Integrating Bio-Inorganic and Analytical Chemistry into an Undergraduate Biochemistry Laboratory

ERIC Educational Resources Information Center

Erasmus, Daniel J.; Brewer, Sharon E.; Cinel, Bruno

2015-01-01

Undergraduate laboratories expose students to a wide variety of topics and techniques in a limited amount of time. This can be a challenge and lead to less exposure to concepts and activities in bio-inorganic chemistry and analytical chemistry that are closely-related to biochemistry. To address this, we incorporated a new iron determination by…

Inorganic chemistry of defensive peroxidases in the human oral cavity.

PubMed

Ashby, M T

2008-10-01

The innate host response system is comprised of various mechanisms for orchestrating host response to microbial infection of the oral cavity. The heterogeneity of the oral cavity and the associated microenvironments that are produced give rise to different chemistries that affect the innate defense system. One focus of this review is on how these spatial differences influence the two major defensive peroxidases of the oral cavity, salivary peroxidase (SPO) and myeloperoxidase (MPO). With hydrogen peroxide (H(2)O(2)) as an oxidant, the defensive peroxidases use inorganic ions to produce antimicrobials that are generally more effective than H(2)O(2) itself. The concentrations of the inorganic substrates are different in saliva vs. gingival crevicular fluid (GCF). Thus, in the supragingival regime, SPO and MPO work in unison for the exclusive production of hypothiocyanite (OSCN(-), a reactive inorganic species), which constantly bathes nascent plaques. In contrast, MPO is introduced to the GCF during inflammatory response, and in that environment it is capable of producing hypochlorite (OCl(-)), a chemically more powerful oxidant that is implicated in host tissue damage. A second focus of this review is on inter-person variation that may contribute to different peroxidase function. Many of these differences are attributed to dietary or smoking practices that alter the concentrations of relevant inorganic species in the oral cavity (e.g.: fluoride, F(-); cyanide, CN(-); cyanate, OCN(-); thiocyanate, SCN(-); and nitrate, NO(3)(-)). Because of the complexity of the host and microflora biology and the associated chemistry, it is difficult to establish the significance of the human peroxidase systems during the pathogenesis of oral diseases. The problem is particularly complex with respect to the gingival sulcus and periodontal pockets (where the very different defensive stratagems of GCF and saliva co-mingle). Despite this complexity, intriguing in vitro and in vivo

The Second Year Course in Inorganic Chemistry at the Free University of Amsterdam.

ERIC Educational Resources Information Center

de Bolster, M. W. G.

1979-01-01

An inorganic chemistry course at the Free University of Amsterdam is part of an integrated program involving practical work and theoretical study for chemistry students. Twelve experiments are required and 11 are performed by students in groups of fours. (Author/SA)

A Visually Attractive "Interconnected Network of Ideas" for Organizing the Teaching and Learning of Descriptive Inorganic Chemistry

ERIC Educational Resources Information Center

Rodgers, Glen E.

2014-01-01

A visually attractive interconnected network of ideas that helps general and second-year inorganic chemistry students make sense of the descriptive inorganic chemistry of the main-group elements is presented. The eight network components include the periodic law, the uniqueness principle, the diagonal effect, the inert-pair effect, the…

Discovery Lab in the Chemistry Lecture Room: Design and Evaluation of Audio-Visual Constructivist Methodology of Teaching Descriptive Inorganic Chemistry.

ERIC Educational Resources Information Center

Young, Barbara N.; Hoffman, Lyubov

Demonstration of chemical reactions is a tool used in the teaching of inorganic descriptive chemistry to enable students to understand the fundamental concepts of chemistry through the use of concrete examples. For maximum benefit, students need to learn through discovery to observe, interpret, hypothesize, and draw conclusions; however, chemical…

Chemistry of Mesoporous Organosilica in Nanotechnology: Molecularly Organic-Inorganic Hybridization into Frameworks.

PubMed

Chen, Yu; Shi, Jianlin

2016-05-01

Organic-inorganic hybrid materials aiming to combine the individual advantages of organic and inorganic components while overcoming their intrinsic drawbacks have shown great potential for future applications in broad fields. In particular, the integration of functional organic fragments into the framework of mesoporous silica to fabricate mesoporous organosilica materials has attracted great attention in the scientific community for decades. The development of such mesoporous organosilica materials has shifted from bulk materials to nanosized mesoporous organosilica nanoparticles (designated as MONs, in comparison with traditional mesoporous silica nanoparticles (MSNs)) and corresponding applications in nanoscience and nanotechnology. In this comprehensive review, the state-of-art progress of this important hybrid nanomaterial family is summarized, focusing on the structure/composition-performance relationship of MONs of well-defined morphology, nanostructure, and nanoparticulate dimension. The synthetic strategies and the corresponding mechanisms for the design and construction of MONs with varied morphologies, compositions, nanostructures, and functionalities are overviewed initially. Then, the following part specifically concentrates on their broad spectrum of applications in nanotechnology, mainly in nanomedicine, nanocatalysis, and nanofabrication. Finally, some critical issues, presenting challenges and the future development of MONs regarding the rational synthesis and applications in nanotechnology are summarized and discussed. It is highly expected that such a unique molecularly organic-inorganic nanohybrid family will find practical applications in nanotechnology, and promote the advances of this discipline regarding hybrid chemistry and materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Degradation of Environmental Contaminants with Water-Soluble Cobalt Catalysts: An Integrative Inorganic Chemistry Investigation

ERIC Educational Resources Information Center

Evans, Alexandra L.; Messersmith, Reid E.; Green, David B.; Fritsch, Joseph M.

2011-01-01

We present an integrative laboratory investigation incorporating skills from inorganic chemistry, analytical instrumentation, and physical chemistry applied to a laboratory-scale model of the environmental problem of chlorinated ethylenes in groundwater. Perchloroethylene (C[subscript 2]Cl[subscript 4], PCE) a common dry cleaning solvent,…

Chemistry, College Level. Annotated Bibliography of Tests.

ERIC Educational Resources Information Center

Educational Testing Service, Princeton, NJ. Test Collection.

Most of the 30 tests cited in this bibliography are those of the American Chemical Society. Subjects covered include physical chemistry, organic chemistry, inorganic chemistry, analytical chemistry, and other specialized areas. The tests are designed only for advanced high school, and both bachelor/graduate degree levels of college students. This…

Polyoxometalates: from inorganic chemistry to materials science.

PubMed

Casañ-Pastor, Nieves; Gómez-Romero, Pedro

2004-05-01

Polyoxometalates have been traditionally the subject of study of molecular inorganic chemistry. Yet, these polynuclear molecules, reminiscent of oxide clusters, present a wide range of structures and with them ideal frameworks for the deployment of a plethora of useful magnetic, electroionic, catalytic, bioactive and photochemical properties. With this in mind, a new trend towards the application of these remarkable species in materials science is beginning to develop. In this review we analyze this trend and discuss two main lines of thought for the application of polyoxometalates as materials. On the one hand, there is their use as clusters with inherently useful properties on themselves, a line which has produced fundamental studies of their magnetic, electronic or photoelectrochemical properties and has shown these clusters as models for quantum-sized oxides. On the other hand, the encapsulation or integration of polyoxometalates into organic, polymeric or inorganic matrices or substrates opens a whole new field within the area of hybrid materials for harnessing the multifunctional properties of these versatile species in a wide variety of applications, ranging from catalysis to energy storage to biomedicine.

Enhanced ozone loss by active inorganic bromine chemistry in the tropical troposphere

NASA Astrophysics Data System (ADS)

Le Breton, Michael; Bannan, Thomas J.; Shallcross, Dudley E.; Khan, M. Anwar; Evans, Mathew J.; Lee, James; Lidster, Richard; Andrews, Stephen; Carpenter, Lucy J.; Schmidt, Johan; Jacob, Daniel; Harris, Neil R. P.; Bauguitte, Stephane; Gallagher, Martin; Bacak, Asan; Leather, Kimberley E.; Percival, Carl J.

2017-04-01

Bromine chemistry, particularly in the tropics, has been suggested to play an important role in tropospheric ozone loss although a lack of measurements of active bromine species impedes a quantitative understanding of its impacts. Recent modelling and measurements of bromine monoxide (BrO) by Wang et al. (2015) have shown current models under predict BrO concentrations over the Pacific Ocean and allude to a missing source of BrO. Here, we present the first simultaneous aircraft measurements of atmospheric bromine monoxide, BrO (a radical that along with atomic Br catalytically destroys ozone) and the inorganic Br precursor compounds HOBr, BrCl and Br2 over the Western Pacific Ocean from 0.5 to 7 km. The presence of 0.17-1.64 pptv BrO and 3.6-8 pptv total inorganic Br from these four species throughout the troposphere causes 10-20% of total ozone loss, and confirms the importance of bromine chemistry in the tropical troposphere; contributing to a 6 ppb decrease in ozone levels due to halogen chemistry. Observations are compared with a global chemical transport model and find that the observed high levels of BrO, BrCl and HOBr can be reconciled by active multiphase oxidation of halide (Br- and Cl-) by HOBr and ozone in cloud droplets and aerosols. Measurements indicate that 99% of the instantaneous free Br in the troposphere up to 8 km originates from inorganic halogen photolysis rather than from photolysis of organobromine species.

Mercouri G. Kanatzidis: Excellence and Innovations in Inorganic and Solid-State Chemistry.

PubMed

Arachchige, Indika U; Armatas, Gerasimos S; Biswas, Kanishka; Subrahmanyam, Kota S; Latturner, Susan; Malliakas, Christos D; Manos, Manolis J; Oh, Youngtak; Polychronopoulou, Kyriaki; P Poudeu, Pierre F; Trikalitis, Pantelis N; Zhang, Qichun; Zhao, Li-Dong; Peter, Sebastian C

2017-07-17

Over the last 3-4 decades, solid-state chemistry has emerged as the forefront of materials design and development. The field has revolutionized into a multidisciplinary subject and matured with a scope of new synthetic strategies, new challenges, and opportunities. Understanding the structure is very crucial in the design of appropriate materials for desired applications. Professor Mercouri G. Kanatzidis has encountered both challenges and opportunities during the course of the discovery of many novel materials. Throughout his scientific career, Mercouri and his group discovered several inorganic compounds and pioneered structure-property relationships. We, a few Ph.D. and postdoctoral students, celebrate his 60th birthday by providing a Viewpoint summarizing his contributions to inorganic solid-state chemistry. The topics discussed here are of significant interest to various scientific communities ranging from condensed matter to green energy production.

A refuge for inorganic chemistry: Bunsen's Heidelberg laboratory.

PubMed

Nawa, Christine

2014-05-01

Immediately after its opening in 1855, Bunsen's Heidelberg laboratory became iconic as the most modern and best equipped laboratory in Europe. Although comparatively modest in size, the laboratory's progressive equipment made it a role model for new construction projects in Germany and beyond. In retrospect, it represents an intermediate stage of development between early teaching facilities, such as Liebig's laboratory in Giessen, and the new 'chemistry palaces' that came into existence with Wöhler's Göttingen laboratory of 1860. As a 'transition laboratory,' Bunsen's Heidelberg edifice is of particular historical interest. This paper explores the allocation of spaces to specific procedures and audiences within the laboratory, and the hierarchies and professional rites of passage embedded within it. On this basis, it argues that the laboratory in Heidelberg was tailored to Bunsen's needs in inorganic and physical chemistry and never aimed at a broad-scale representation of chemistry as a whole. On the contrary, it is an example of early specialisation within a chemical laboratory preceding the process of differentiation into chemical sub-disciplines. Finally, it is shown that the relatively small size of this laboratory, and the fact that after ca. 1860 no significant changes were made within the building, are inseparably connected to Bunsen's views on chemistry teaching.

Report of the Polymer Core Course Committee: Inclusion of Polymer Topics into Undergraduate Inorganic Chemistry Courses.

ERIC Educational Resources Information Center

Miller, Norman E.; And Others

1984-01-01

Suggests polymer topics for study in inorganic chemistry courses. Commercial materials (including list of inorganic compounds utilized in polymer industry), anchored metal catalysis, polymers modified or formed by coordination, polysiloxanes, phosphazene or phosphonitrilic halide polymers, and hetergeneous polymerization catalysts are considered.…

A Wiki-Based Group Project in an Inorganic Chemistry Foundation Course

ERIC Educational Resources Information Center

Kristian, Kathleen E.

2015-01-01

A semester-long group project that utilizes wiki sites to enhance collaboration was developed for a foundation course in inorganic chemistry. Through structured assignments, student groups use metal-based or metal-combating therapeutic agents as a model for applying and understanding course concepts; they also gain proficiency with scientific- and…

Six Impossible Mechanisms before Breakfast: Arrow Pushing as an Instructional Device in Inorganic Chemistry

ERIC Educational Resources Information Center

Berg, Steffen; Ghosh, Abhik

2013-01-01

In a recent article by the authors, the suggestion was made that arrow pushing, a widely used tool in organic chemistry, could also be profitably employed in the teaching of introductory inorganic chemistry. A number of relatively simple reactions were used to illustrate this thesis, raising the question whether the same approach might rationalize…

The Inorganic Illustrator: A 3-D Graphical Supplement for Inorganic and Bioinorganic Chemistry Courses Distributed on CD-ROM

NASA Astrophysics Data System (ADS)

Childs, Scott L.; Hagen, Karl S.

1996-10-01

The visualization of molecular and solid state chemical structures in three dimensions is a particularly difficult problem for students to overcome when the primary means of communication is the two-dimensional world of textbooks, blackboards, and overhead projector screens. Recent editions of popular textbooks in organic, inorganic, and biochemistry have included stereoviews of molecules to aid the student, and stereoviews of crystal structures have been used in inorganic chemistry publications for many years. These are powerful aids for visualizing complex molecules, but with the exception of the biochemistry text mentioned above, they are limited to single, static images generally in black and white. Molecular model kits are routinely used very effectively in organic chemistry but their utility in inorganic chemistry is limited to all but the most simple molecules encountered. Now that personal computers are generally accessible and multimedia tools are starting to make an appearance in chemistry lecture halls (1), we can make our inorganic and bioinorganic chemistry and crystallography lectures come alive with the aid of the computer-based resources, which are the essence of this project. As part of this project we are accumulating a database of representative crystal structures of main group molecules, coordination complexes, organometallic compounds, small metalloproteins, bioinorganic model complexes, clusters, and solid state materials in Chem3D Plus format to be viewed with Chem3D Viewer, which is free software from Cambridge Scientific Computing. We are also generating a library of high-quality graphic images of these same molecules and structures using Cerius2 package from Molecular Simulations. These include polyhedral representations of clusters and solid state structures (see Fig. 1). Figure 1. Representation of the user interface: the title page and an example of polyhedral and ball-and-stick representation of an octanuclear iron-oxo cluster. The

The biological inorganic chemistry of zinc ions.

PubMed

Krężel, Artur; Maret, Wolfgang

2016-12-01

The solution and complexation chemistry of zinc ions is the basis for zinc biology. In living organisms, zinc is redox-inert and has only one valence state: Zn(II). Its coordination environment in proteins is limited by oxygen, nitrogen, and sulfur donors from the side chains of a few amino acids. In an estimated 10% of all human proteins, zinc has a catalytic or structural function and remains bound during the lifetime of the protein. However, in other proteins zinc ions bind reversibly with dissociation and association rates commensurate with the requirements in regulation, transport, transfer, sensing, signalling, and storage. In contrast to the extensive knowledge about zinc proteins, the coordination chemistry of the "mobile" zinc ions in these processes, i.e. when not bound to proteins, is virtually unexplored and the mechanisms of ligand exchange are poorly understood. Knowledge of the biological inorganic chemistry of zinc ions is essential for understanding its cellular biology and for designing complexes that deliver zinc to proteins and chelating agents that remove zinc from proteins, for detecting zinc ion species by qualitative and quantitative analysis, and for proper planning and execution of experiments involving zinc ions and nanoparticles such as zinc oxide (ZnO). In most investigations, reference is made to zinc or Zn 2+ without full appreciation of how biological zinc ions are buffered and how the d-block cation Zn 2+ differs from s-block cations such as Ca 2+ with regard to significantly higher affinity for ligands, preference for the donor atoms of ligands, and coordination dynamics. Zinc needs to be tightly controlled. The interaction with low molecular weight ligands such as water and inorganic and organic anions is highly relevant to its biology but in contrast to its coordination in proteins has not been discussed in the biochemical literature. From the discussion in this article, it is becoming evident that zinc ion speciation is

Arrow Pushing: A Rational, Participatory Approach to Teaching Descriptive Inorganic Chemistry

ERIC Educational Resources Information Center

Berg, Steffen; Ghosh, Abhik

2011-01-01

Inorganic chemistry at core consists of a vast array of molecules and chemical reactions. To master the subject, students must learn to think intelligently about this vast body of facts, a feat seldom accomplished in an introductory course. All too often, young undergraduate students perceive the field as an amorphous and illogical body of…

An Alternative Educational Approach for an Inorganic Chemistry Laboratory Course in Industrial and Chemical Engineering

ERIC Educational Resources Information Center

Garces, Andres; Sanchez-Barba, Luis Fernando

2011-01-01

We describe an alternative educational approach for an inorganic chemistry laboratory module named "Experimentation in Chemistry", which is included in Industrial Engineering and Chemical Engineering courses. The main aims of the new approach were to reduce the high levels of failure and dropout on the module and to make the content match the…

Chemistry Division: Annual progress report for period ending March 31, 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-08-01

This report is divided into the following sections: coal chemistry; aqueous chemistry at high temperatures and pressures; geochemistry of crustal processes to high temperatures and pressures; chemistry of advanced inorganic materials; structure and dynamics of advanced polymeric materials; chemistry of transuranium elements and compounds; separations chemistry; reactions and catalysis in molten salts; surface science related to heterogeneous catalysis; electron spectroscopy; chemistry related to nuclear waste disposal; computational modeling of security document printing; and special topics. (DLC)

Targeting the folate receptor: improving efficacy in inorganic medicinal chemistry.

PubMed

Carron, Pauraic Mc; Crowley, Aisling; O'Shea, Denis; McCann, Malachy; Howe, Orla; Hunt, Mary; Devereux, Michael

2018-02-09

The discovery of the high-affinity, high-specificity folate receptor in mamalian kidney cells, coupled with the ability of folate to enter cells by folate receptor-mediated endocytosis and the subsequent elucidation of the folate receptor's overexpression in specific cancer cell types; heralded the arrival of the area of chemotherapeutic folate targeting. The application of purely organic folate-based small-molecule drug conjugates that selectively target the folate receptor, which is over expressed in several diseases such as cancer, is well established. The application of inorganic folate-targeted drugs offers significant potential to expand and enhance this therapeutic approach. From the data made available to date, it is apparent that this aspect of inorganic medicinal chemistry is in its youth but has the capability to contribute greatly to cancer research, both in therapy and diagnosis. The union of folate-receptor targeting and inorganic medicine may also lead to the development of treatments for disorders such as chronic-inflammation, tuberculosis, neurodegenerative disease and leishmaniasis. In this review, we summarize what is known about the coordination chemistry of folic acid and the therapeutic potential of such complexes. We also describe approaches adopted to conjugate platinum drugs to folate- or folate-carrier- systems and their prospective ability to overcome problems associated with unwanted side-effects and resistance by improving their delivery and/or selectivity. The literature pertaining to non-platinum metal complex conjugates with folic acid is also reviewed revealing that this is an area that offers significant potential to develop targeted therapeutic approaches in areas such as chemotherapy and molecular imaging for diagnostics. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Engineering functional inorganic-organic hybrid systems: advances in siRNA therapeutics.

PubMed

Shen, Jianliang; Zhang, Wei; Qi, Ruogu; Mao, Zong-Wan; Shen, Haifa

2018-03-21

Cancer treatment still faces a lot of obstacles such as tumor heterogeneity, drug resistance and systemic toxicities. Beyond the traditional treatment modalities, exploitation of RNA interference (RNAi) as an emerging approach has immense potential for the treatment of various gene-caused diseases including cancer. The last decade has witnessed enormous research and achievements focused on RNAi biotechnology. However, delivery of small interference RNA (siRNA) remains a key challenge in the development of clinical RNAi therapeutics. Indeed, functional nanomaterials play an important role in siRNA delivery, which could overcome a wide range of sequential physiological and biological obstacles. Nanomaterial-formulated siRNA systems have potential applications in protection of siRNA from degradation, improving the accumulation in the target tissues, enhancing the siRNA therapy and reducing the side effects. In this review, we explore and summarize the role of functional inorganic-organic hybrid systems involved in the siRNA therapeutic advancements. Additionally, we gather the surface engineering strategies of hybrid systems to optimize for siRNA delivery. Major progress in the field of inorganic-organic hybrid platforms including metallic/non-metallic cores modified with organic shells or further fabrication as the vectors for siRNA delivery is discussed to give credit to the interdisciplinary cooperation between chemistry, pharmacy, biology and medicine.

Chemistry Division annual progress report for period ending April 30, 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poutsma, M.L.; Ferris, L.M.; Mesmer, R.E.

1993-08-01

The Chemistry Division conducts basic and applied chemical research on projects important to DOE`s missions in sciences, energy technologies, advanced materials, and waste management/environmental restoration; it also conducts complementary research for other sponsors. The research are arranged according to: coal chemistry, aqueous chemistry at high temperatures and pressures, geochemistry, chemistry of advanced inorganic materials, structure and dynamics of advanced polymeric materials, chemistry of transuranium elements and compounds, chemical and structural principles in solvent extraction, surface science related to heterogeneous catalysis, photolytic transformations of hazardous organics, DNA sequencing and mapping, and special topics.

Undergraduate Professional Education in Chemistry: Guidelines and Evaluation Procedures.

ERIC Educational Resources Information Center

American Chemical Society, Washington, DC.

Provided are guidelines for evaluating undergraduate professional education in chemistry. The guidelines summarize an approved program as including: 400 hours of classroom work; 500 hours of laboratory work; a core curriculum covering principles of analytical, inorganic, organic, and physical chemistry; 1 year of advanced work in chemistry or…

Inorganic Chemistry Solutions to Semiconductor Nanocrystal Problems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvarado, Samuel R.; Guo, Yijun; Ruberu, T. Purnima A.

2014-03-15

The optoelectronic and chemical properties of semiconductor nanocrystals heavily depend on their composition, size, shape and internal structure, surface functionality, etc. Available strategies to alter these properties through traditional colloidal syntheses and ligand exchange methods place a premium on specific reaction conditions and surfactant combinations. In this invited review, we apply a molecular-level understanding of chemical precursor reactivity to reliably control the morphology, composition and intimate architecture (core/shell vs. alloyed) of semiconductor nanocrystals. We also describe our work aimed at achieving highly selective, low-temperature photochemical methods for the synthesis of semiconductor–metal and semiconductor–metal oxide photocatalytic nanocomposites. In addition, we describemore » our work on surface modification of semiconductor nanocrystal quantum dots using new approaches and methods that bypass ligand exchange, retaining the nanocrystal's native ligands and original optical properties, as well as on spectroscopic methods of characterization useful in determining surface ligand organization and chemistry. Using recent examples from our group and collaborators, we demonstrate how these efforts have lead to faster, wider and more systematic application of semiconductor nanocrystal-based materials to biological imaging and tracking, and to photocatalysis of unconventional substrates. We believe techniques and methods borrowed from inorganic chemistry (including coordination, organometallic and solid state chemistry) have much to offer in reaching a better understanding of the synthesis, functionalization and real-life application of such exciting materials as semiconductor nanocrystals (quantum dots, rods, tetrapods, etc.).« less

Ionic Liquids and Poly(ionic liquid)s for Morphosynthesis of Inorganic Materials.

PubMed

Gao, Min-Rui; Yuan, Jiayin; Antonietti, Markus

2017-04-24

Ionic liquids (ILs) are new, innovative ionic solvents with rich physicochemical properties and intriguing pre-organized solvent structures; these materials offer great potential to impact across versatile areas of scientific research, for example, synthetic inorganic chemistry. Recent use of ILs as precursors, templates, and solvents has led to inorganic materials with tailored sizes, dimensionalities, morphologies, and functionalities that are difficult to obtain, or even not accessible, by using conventional solvents. Poly(ionic liquid)s (PILs) polymerized from IL monomers also raise the prospect of modifying nucleation, growth, and crystallization of inorganic objects, shedding light on the synthesis of a wide range of new materials. Here we survey recent key progress in using ILs and PILs in the field of synthetic inorganic chemistry. As well as highlighting the unique features of ILs and PILs that enable advanced synthesis, the effects of adding other solvents to the final products, along with the emerging applications of the created inorganic materials will be discussed. We finally provide an outlook on several development opportunities that could lead to new advancements of this exciting research field. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and Metalation of a Ligand: An Interdisciplinary Laboratory Experiment for Second-Year Organic and Introductory Inorganic Chemistry Students

ERIC Educational Resources Information Center

Kasting, Benjamin J.; Bowser, Andrew K.; Anderson-Wile, Amelia M.; Wile, Bradley M.

2015-01-01

An interdisciplinary laboratory experiment involving second-year undergraduate organic chemistry and introductory inorganic chemistry undergraduate students is described. Organic chemistry students prepare a series of amine-bis(phenols) via a Mannich reaction, and characterize their products using melting point; FTIR; and [superscript 1]H,…

Integrating bio-inorganic and analytical chemistry into an undergraduate biochemistry laboratory.

PubMed

Erasmus, Daniel J; Brewer, Sharon E; Cinel, Bruno

2015-01-01

Undergraduate laboratories expose students to a wide variety of topics and techniques in a limited amount of time. This can be a challenge and lead to less exposure to concepts and activities in bio-inorganic chemistry and analytical chemistry that are closely-related to biochemistry. To address this, we incorporated a new iron determination by atomic absorption spectroscopy exercise as part of a five-week long laboratory-based project on the purification of myoglobin from beef. Students were required to prepare samples for chemical analysis, operate an atomic absorption spectrophotometer, critically evaluate their iron data, and integrate these data into a study of myoglobin. © 2015 The International Union of Biochemistry and Molecular Biology.

Recent advances in inorganic nanoparticle-based drug delivery systems.

PubMed

Murakami, Tatsuya; Tsuchida, Kunihiro

2008-02-01

Drug delivery systems, designed to enhance drug efficacy and reduce their adverse effects, have evolved accompanied by the development of novel materials. Nanotechnology is an emerging scientific area that has created a variety of intriguing inorganic nanoparticles. In this review, we focus on the feasibility of inorganic nanoparticles, including iron oxide nanoparticles, gold nanoparticles, fullerenes and carbon nanohorns, as drug carriers, and summarize recent advances in this field.

Rotor-Shaped Cyclopentadienyltetraphenyl-Cyclobutadienecobalt: An Advanced Inorganic Experiment

ERIC Educational Resources Information Center

MacFarland, Darren K.; Gorodetzer, Rebecca

2005-01-01

Organometallic complex synthesis in advanced inorganic or organic courses usually begin with the synthesis of ferrocene. A synthetic experiment of an alternative compound that has a more interesting structure and the same air stability that makes ferrocene desirable is presented.

Bringing inorganic chemistry to life with inspiration from R. J. P. Williams.

PubMed

Hill, H Allen O; Sadler, Peter J

2016-03-01

Our appreciation of the scholarly ideas and thinking of Bob Williams is illustrated here by a few of the areas in which he inspired us. His journey to bring inorganic chemistry to life began with an early interest in analytical chemistry, rationalising the relative stabilities of metal coordination complexes (The Irving-Williams Series), and elucidating the organometallic redox chemistry of vitamin B12. He (and Vallee) recognised that metal ions are in energised (entatic) states in proteins and enzymes, which themselves are dynamic structures of rods and springs. He played a key role in helping Rosenberg to pave the road toward the clinic for the anticancer drug cisplatin. He believed that evolution is not just dependent on DNA, but also on the metallome. Organisms and the environment are one system: does DNA code directly for all the essential elements of life?

The crystal chemistry of inorganic metal borohydrides and their relation to metal oxides.

PubMed

Černý, Radovan; Schouwink, Pascal

2015-12-01

The crystal structures of inorganic homoleptic metal borohydrides are analysed with respect to their structural prototypes found amongst metal oxides in the inorganic databases such as Pearson's Crystal Data [Villars & Cenzual (2015). Pearson's Crystal Data. Crystal Structure Database for Inorganic Compounds, Release 2014/2015, ASM International, Materials Park, Ohio, USA]. The coordination polyhedra around the cations and the borohydride anion are determined, and constitute the basis of the structural systematics underlying metal borohydride chemistry in various frameworks and variants of ionic packing, including complex anions and the packing of neutral molecules in the crystal. Underlying nets are determined by topology analysis using the program TOPOS [Blatov (2006). IUCr CompComm. Newsl. 7, 4-38]. It is found that the Pauling rules for ionic crystals apply to all non-molecular borohydride crystal structures, and that the latter can often be derived by simple deformation of the close-packed anionic lattices c.c.p. and h.c.p., by partially removing anions and filling tetrahedral or octahedral sites. The deviation from an ideal close packing is facilitated in metal borohydrides with respect to the oxide due to geometrical and electronic considerations of the BH4(-) anion (tetrahedral shape, polarizability). This review on crystal chemistry of borohydrides and their similarity to oxides is a contribution which should serve materials engineers as a roadmap to design new materials, synthetic chemists in their search for promising compounds to be prepared, and materials scientists in understanding the properties of novel materials.

Review: Impacts of permafrost degradation on inorganic chemistry of surface fresh water

NASA Astrophysics Data System (ADS)

Colombo, Nicola; Salerno, Franco; Gruber, Stephan; Freppaz, Michele; Williams, Mark; Fratianni, Simona; Giardino, Marco

2018-03-01

Recent studies have shown that climate change is impacting the inorganic chemical characteristics of surface fresh water in permafrost areas and affecting aquatic ecosystems. Concentrations of major ions (e.g., Ca2 +, Mg2 +, SO42 -, NO3-) can increase following permafrost degradation with associated deepening of flow pathways and increased contributions of deep groundwater. In addition, thickening of the active layer and melting of near-surface ground ice can influence inorganic chemical fluxes from permafrost into surface water. Permafrost degradation has also the capability to modify trace element (e.g., Ni, Mn, Al, Hg, Pb) contents in surface water. Although several local and regional modifications of inorganic chemistry of surface fresh water have been attributed to permafrost degradation, a comprehensive review of the observed changes is lacking. The goal of this paper is to distil insight gained across differing permafrost settings through the identification of common patterns in previous studies, at global scale. In this review we focus on three typical permafrost configurations (pervasive permafrost degradation, thermokarst, and thawing rock glaciers) as examples and distinguish impacts on (i) major ions and (ii) trace elements. Consequences of warming climate have caused spatially-distributed progressive increases of major ion and trace element delivery to surface fresh water in both polar and mountain areas following pervasive permafrost degradation. Moreover, localised releases of major ions and trace elements to surface water due to the liberation of soluble materials sequestered in permafrost and ground ice have been found in ice-rich terrains both at high latitude (thermokarst features) and high elevation (rock glaciers). Further release of solutes and related transport to surface fresh water can be expected under warming climatic conditions. However, complex interactions among several factors able to influence the timing and magnitude of the impacts

Improving Student Achievement and Satisfaction by Adopting a Blended Learning Approach to Inorganic Chemistry

ERIC Educational Resources Information Center

Williams, Neil A.; Bland, Will; Christie, Gillian

2008-01-01

A blended learning approach to the teaching of a level 2 inorganic chemistry module is presented. Lectures were replaced by study packs, which were supported by formative on-line assessment delivered via Blackboard and a programme of 20 workshops. Learning activities written using the Lockwood format were included in the study pack to facilitate…

The Chemistry of Inorganic Precursors during the Chemical Deposition of Films on Solid Surfaces.

PubMed

Barry, Seán T; Teplyakov, Andrew V; Zaera, Francisco

2018-03-20

The deposition of thin solid films is central to many industrial applications, and chemical vapor deposition (CVD) methods are particularly useful for this task. For one, the isotropic nature of the adsorption of chemical species affords even coverages on surfaces with rough topographies, an increasingly common requirement in microelectronics. Furthermore, by splitting the overall film-depositing reactions into two or more complementary and self-limiting steps, as it is done in atomic layer depositions (ALD), film thicknesses can be controlled down to the sub-monolayer level. Thanks to the availability of a vast array of inorganic and metalorganic precursors, CVD and ALD are quite versatile and can be engineered to deposit virtually any type of solid material. On the negative side, the surface chemistry that takes place in these processes is often complex, and can include undesirable side reactions leading to the incorporation of impurities in the growing films. Appropriate precursors and deposition conditions need to be chosen to minimize these problems, and that requires a proper understanding of the underlying surface chemistry. The precursors for CVD and ALD are often designed and chosen based on their known thermal chemistry from inorganic chemistry studies, taking advantage of the vast knowledge developed in that field over the years. Although a good first approximation, however, this approach can lead to wrong choices, because the reactions of these precursors at gas-solid interfaces can be quite different from what is seen in solution. For one, solvents often aid in the displacement of ligands in metalorganic compounds, providing the right dielectric environment, temporarily coordinating to the metal, or facilitating multiple ligand-complex interactions to increase reaction probabilities; these options are not available in the gas-solid reactions associated with CVD and ALD. Moreover, solid surfaces act as unique "ligands", if these reactions are to be

Inorganic chemistry in nuclear imaging and radiotherapy: current and future directions

PubMed Central

Carroll, Valerie; Demoin, Dustin W.; Hoffman, Timothy J; Jurisson, Silvia S

2013-01-01

Summary Radiometals play an important role in diagnostic and therapeutic radiopharmaceuticals. This field of radiochemistry is multidisciplinary, involving radiometal production, separation of the radiometal from its target, chelate design for complexing the radiometal in a biologically stable environment, specific targeting of the radiometal to its in vivo site, and nuclear imaging and/or radiotherapy applications of the resultant radiopharmaceutical. The critical importance of inorganic chemistry in the design and application of radiometal-containing imaging and therapy agents is described from a historical perspective to future directions. PMID:25382874

Recent Advances in Cyanamide Chemistry: Synthesis and Applications.

PubMed

Prabhath, M R Ranga; Williams, Luke; Bhat, Shreesha V; Sharma, Pallavi

2017-04-12

The application of alkyl and aryl substituted cyanamides in synthetic chemistry has diversified multi-fold in recent years. In this review, we discuss recent advances (since 2012) in the chemistry of cyanamides and detail their application in cycloaddition chemistry, aminocyanation reactions, as well as electrophilic cyanide-transfer agents and their unique radical and coordination chemistry.

Intracellular Chemistry: Integrating Molecular Inorganic Catalysts with Living Systems.

PubMed

Ngo, Anh H; Bose, Sohini; Do, Loi H

2018-03-23

This concept article focuses on the rapid growth of intracellular chemistry dedicated to the integration of small-molecule metal catalysts with living cells and organisms. Although biological systems contain a plethora of biomolecules that can deactivate inorganic species, researchers have shown that small-molecule metal catalysts could be engineered to operate in heterogeneous aqueous environments. Synthetic intracellular reactions have recently been reported for olefin hydrogenation, hydrolysis/oxidative cleavage, azide-alkyne cycloaddition, allylcarbamate cleavage, C-C bond cross coupling, and transfer hydrogenation. Other promising targets for new biocompatible reaction discovery will also be discussed, with a special emphasis on how such innovations could lead to the development of novel technologies and chemical tools. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

21 CFR 862.1580 - Phosphorus (inorganic) test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Phosphorus (inorganic) test system. 862.1580... (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1580 Phosphorus (inorganic) test system. (a) Identification. A phosphorus (inorganic) test...

21 CFR 862.1580 - Phosphorus (inorganic) test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Phosphorus (inorganic) test system. 862.1580... (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1580 Phosphorus (inorganic) test system. (a) Identification. A phosphorus (inorganic) test...

Advanced Chemistry for Operators. Training Module 1.321.3.77.

ERIC Educational Resources Information Center

Kirkwood Community Coll., Cedar Rapids, IA.

This document is an instructional module package prepared in objective form for use by an instructor familiar with inorganic and general organic chemistry as applied to water and wastewater treatment. Included are objectives, instructor guides, and student handouts. The module contains material related to chemical reactions in water solutions,…

Advanced Organic Chemistry: Reactions and Mechanisms (by Bernard Miller)

NASA Astrophysics Data System (ADS)

Berger, Daniel

1998-12-01

Prentice Hall: Upper Saddle River, NJ, 1998. 338 pp, index. ISBN 0-13-373275-4. $59.00. Recently several short texts on intermediate organic chemistry have been published, intended for use in one-term courses for advanced undergraduates and for graduate students who need more background before taking a graduate-level course. These books fill a need not fully met by graduate-level texts such as Lowry and Richardson's Mechanism and Theory in Organic Chemistry or Carey and Sundberg's Advanced Organic Chemistry.

Determining the Quantum Efficiency for Activation of an Organometallic Photoinitiator for Cationic Polymerization: An Experiment for the Physical or Inorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Hayes, David M.; Mahar, Maura; Schnabel, R. Chris; Shah, Paras; Lees, Alistair J.; Jakubek, Vladimir

2007-01-01

We present a new laboratory experiment on the photochemistry of organometallic [eta][superscript 5],[eta][superscript 6]-mixed-sandwich compounds, which is suitable for both the physical chemistry and inorganic chemistry laboratory. Specifically, students use 1,10-phenanthroline to trap the intermediate formed when…

On some problems of inorganic supramolecular chemistry.

PubMed

Pervov, Vladislav S; Zotova, Anna E

2013-12-02

In this study, some features that distinguish inorganic supramolecular host-guest objects from traditional architectures are considered. Crystalline inorganic supramolecular structures are the basis for the development of new functional materials. Here, the possible changes in the mechanism of crystalline inorganic supramolecular structure self-organization at high interaction potentials are discussed. The cases of changes in the host structures and corresponding changes in the charge states under guest intercalation, as well as their impact on phase stability and stoichiometry are considered. It was demonstrated that the deviation from the geometrical and topological complementarity conditions may be due to the additional energy gain from forming inorganic supramolecular structures. It has been assumed that molecular recognition principles can be employed for the development of physicochemical analysis and interpretation of metastable states in inorganic crystalline alloys. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced Chemistry Collection, 2nd Edition

NASA Astrophysics Data System (ADS)

2001-11-01

Software requirements are given in Table 3. Some programs have additional special requirements. Please see the individual program abstracts at JCE Online or the documentation included on the CD-ROM for more specific information. Table 3. General software requirements for the Advanced Chemistry Collection.

Literature Cited

1. General Chemistry Collection, 5th ed.; J. Chem. Educ. Software, 2001, SP16.
2. Advanced Chemistry Collection; J. Chem. Educ. Software, 2001, SP28.

Inorganic sulfur-nitrogen compounds: from gunpowder chemistry to the forefront of biological signaling.

PubMed

Cortese-Krott, Miriam M; Butler, Anthony R; Woollins, J Derek; Feelisch, Martin

2016-04-14

The reactions between inorganic sulfur and nitrogen-bearing compounds to form S-N containing species have a long history and, besides assuming importance in industrial synthetic processes, are of relevance to microbial metabolism; waste water treatment; aquatic, soil and atmospheric chemistry; and combustion processes. The recent discovery that hydrogen sulfide and nitric oxide exert often similar, sometimes mutually dependent effects in a variety of biological systems, and that the chemical interaction of these two species leads to formation of S-N compounds brought this chemistry to the attention of physiologists, biochemists and physicians. We here provide a perspective about the potential role of S-N compounds in biological signaling and briefly review their chemical properties and bioactivities in the context of the chronology of their discovery. Studies of the biological role of NO revealed why its chemistry is ideally suited for the tasks Nature has chosen for it; realising how the distinctive properties of sulfur can enrich this bioactivity does much to revive 'die Freude am experimentellen Spiel' of the pioneers in this field.

Electrochemistry of (Dihapto-Buckminster-Fullerene) Pentacarbonyl Tungsten(0): An Experiment for the Inorganic Chemistry Laboratory, Part III

ERIC Educational Resources Information Center

Igartua-Nieves, Elvin; Ocasio-Delgado, Yessenia; Rivera-Pagan, Jose; Cortes-Figueroa, Jose E.

2007-01-01

Cyclic voltammetry experiments on [60]fullerene, (C[subscript 60]), and (dihapto-[60]fullerene) pentacarbonyl tungsten(0), ([eta][superscript 2]-C[subscript 60])W(CO)[subscript 5], constitute an educational experiment for the inorganic chemistry laboratory with a primary objective to teach the chemical interpretation of a voltammogram, in…

Synthesis and Characterization of a Layered Manganese Oxide: Materials Chemistry for the Inorganic or Instrumental Methods Lab

ERIC Educational Resources Information Center

Ching, Stanton; Neupane, Ram P.; Gray, Timothy P.

2006-01-01

A three-week laboratory project involving synthesis and characterization of a layered manganese oxide provides an excellent vehicle for teaching important concepts of inorganic chemistry and instrumental methods related to non-molecular systems. Na-birnessite is an easily prepared manganese oxide with a 7 A interlayer spacing and Na[superscript +]…

Organic templates for the generation of inorganic materials.

PubMed

van Bommel, Kjeld J C; Friggeri, Arianna; Shinkai, Seiji

2003-03-03

Mankind's fascination with shapes and patterns, many examples of which come from nature, has greatly influenced areas such as art and architecture. Science too has long since been interested in the origin of shapes and structures found in nature. Whereas organic chemistry in general, and supramolecular chemistry especially, has been very successful in creating large superstructures of often stunning morphology, inorganic chemistry has lagged behind. Over the last decade, however, researchers in various fields of chemistry have been studying novel methods through which the shape of inorganic materials can be controlled at the micro- or even nanoscopic level. A method that has proven very successful is the formation of inorganic structures under the influence of (bio)organic templates, which has resulted in the generation of a large variety of structured inorganic structures that are currently unattainable through any other method.

BIBLIOGRAPHIC GUIDE FOR ADVANCED PLACEMENT, CHEMISTRY.

ERIC Educational Resources Information Center

WILLIAMS, HARRY; KING, CLYDE

REFERENCES AND AUDIOVISUAL MATERIALS ARE LISTED IN THIS GUIDE FOR SECONDARY SCHOOL ADVANCED PLACEMENT CHEMISTRY TEACHERS AND LIBRARIANS. BOOKS, PERIODICALS, WALL CHARTS, FILMS, AND FILMSTRIPS ARE INCLUDED. CITATIONS ARE COMPLETE AND INCLUDE INFORMATION PERTINENT TO THE ACQUISITION OF THE MATERIALS. (AG)

Advances in organic-inorganic hybrid sorbents for the extraction of organic and inorganic pollutants in different types of food and environmental samples.

PubMed

Ng, Nyuk-Ting; Kamaruddin, Amirah Farhan; Wan Ibrahim, Wan Aini; Sanagi, Mohd Marsin; Abdul Keyon, Aemi S

2018-01-01

The efficiency of the extraction and removal of pollutants from food and the environment has been an important issue in analytical science. By incorporating inorganic species into an organic matrix, a new material known as an organic-inorganic hybrid material is formed. As it possesses high selectivity, permeability, and mechanical and chemical stabilities, organic-inorganic hybrid materials constitute an emerging research field and have become popular to serve as sorbents in various separaton science methods. Here, we review recent significant advances in analytical solid-phase extraction employing organic-inorganic composite/nanocomposite sorbents for the extraction of organic and inorganic pollutants from various types of food and environmental matrices. The physicochemical characteristics, extraction properties, and analytical performances of sorbents are discussed; including morphology and surface characteristics, types of functional groups, interaction mechanism, selectivity and sensitivity, accuracy, and regeneration abilities. Organic-inorganic hybrid sorbents combined with extraction techniques are highly promising for sample preparation of various food and environmental matrixes with analytes at trace levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tuberculosis: An Inorganic Medicinal Chemistry Perspective.

PubMed

Viganor, Livia; Skerry, Ciaran; McCann, Malachy; Devereux, Michael

2015-01-01

Tuberculosis (TB) which is caused by the resilient pathogen Mycobacterium tuberculosis (MTB) has re-emerged to become a leading public health problem in the world. The growing number of multi-drug resistant MTB strains and the more recently emerging problem with the extensively drug resistant strains of the pathogen are greatly undermining conventional anti-TB therapeutic strategies which are lengthy and expose patients to toxicity and other unwanted side effects. The search for new anti-TB drugs essentially involves either the repurposing of existing organic drugs which are now off patent and already FDA approved, the synthesis of modified analogues of existing organic drugs, with the aim of shortening and improving drug treatment for the disease, or the search for novel structures that offer the possibility of new mechanisms of action against the mycobacterium. Inorganic medicinal chemistry offers an alternative to organic drugs through opportunities for the design of therapeutics that target different biochemical pathways. The incorporation of metal ions into the molecular structure of a potential drug offers the medicinal chemist an opportunity to exploit structural diversity, have access to various oxidation states of the metal and also offer the possibility of enhancing the activity of an established organic drug through its coordination to the metal centre. In this review, we summarize what is currently known about the antitubercular capability of metal complexes, their mechanisms of action and speculate on their potential applications in the clinic.

Recent advances in computational actinoid chemistry.

PubMed

Wang, Dongqi; van Gunsteren, Wilfred F; Chai, Zhifang

2012-09-07

We briefly review advances in computational actinoid (An) chemistry during the past ten years in regard to two issues: the geometrical and electronic structures, and reactions. The former addresses the An-O, An-C, and M-An (M is a metal atom including An) bonds in the actinoid molecular systems, including actinoid oxo and oxide species, actinoid-carbenoid, dinuclear and diatomic systems, and the latter the hydration and ligand exchange, the disproportionation, the oxidation, the reduction of uranyl, hydroamination, and the photolysis of uranium azide. Concerning their relevance to the electronic structures and reactions of actinoids and their importance in the development of an advanced nuclear fuel cycle, we also mentioned the work on actinoid carbides and nitrides, which have been proposed to be candidates of the next generation of nuclear fuel, and the oxidation of PuO(x), which is important to understand the speciation of actinoids in the environment, followed by a brief discussion on the urgent need for a heavier involvement of computational actinoid chemistry in developing advanced reprocessing protocols of spent nuclear fuel. The paper is concluded with an outlook.

Influence of solution chemistry on the boron content in inorganic calcite grown in artificial seawater

NASA Astrophysics Data System (ADS)

Uchikawa, Joji; Harper, Dustin T.; Penman, Donald E.; Zachos, James C.; Zeebe, Richard E.

2017-12-01

The ratio of boron to calcium (B/Ca) in marine biogenic carbonates has been proposed as a proxy for properties of seawater carbonate chemistry. Applying this proxy to planktic foraminifera residing in the surface seawater largely in equilibrium with the atmosphere may provide a valuable handle on past atmospheric CO2 concentrations. However, precise controls on B/Ca in planktic foraminifera remain enigmatic because it has been shown to depend on multiple physicochemical seawater properties. To help establish a firm inorganic basis for interpreting the B/Ca records, we examined the effect of a suite of chemical parameters ([Ca2+], pH, [DIC], salinity and [PO43-]) on B/Ca in inorganic calcite precipitated in artificial seawater. These parameters were primarily varied individually while keeping all others constant, but we also tested the influence of pH and [DIC] at a constant calcite precipitation rate (R) by concurrent [Ca2+] adjustments. In the simple [Ca2+], pH and [DIC] experiments, both R and B/Ca increased with these parameters. In the pH-[Ca2+] and [DIC]-[Ca2+] experiments at constant R, on the other hand, B/Ca was invariant at different pH and decreased with [DIC], respectively. These patterns agree with the behavior of solution [BTotal/DIC] ratio such that, at a fixed [BTotal], it is independent of pH but decreases with [DIC]. Based on these results, R and [BTotal/DIC] ratio appear to be the primary controls on B/Ca in inorganic calcite, suggesting that both B(OH)4- and B(OH)3 are possibly involved in B incorporation. Moreover, B/Ca modestly increased with salinity and [PO43-]. Inorganic calcite precipitated at higher R and in the presence of oxyanions such as SO42- and PO43- in growth solutions often undergoes surface roughening due to formation of crystallographic defects, vacancies and, occasionally, amorphous/hydrous CaCO3. These non-lattice sites may provide additional space for B, particularly B(OH)3. Consequently, besides the macroscopic influence of

Synthesis and Small Molecule Exchange Studies of a Magnesium Bisformate Metal-Organic Framework: An Experiment in Host-Guest Chemistry for the Undergraduate Laboratory

ERIC Educational Resources Information Center

Rood, Jeffrey A.; Henderson, Kenneth W.

2013-01-01

concepts of host-guest chemistry and size exclusion in porous metal-organic frameworks (MOFs). The experiment has been successfully carried out in both introductory and advanced-level inorganic chemistry laboratories. Students synthesized the porous MOF, alpha-Mg[subscript…

Inorganic nanotubes.

PubMed

Tenne, Reshef; Rao, C N R

2004-10-15

Following the discovery of carbon fullerenes and carbon nanotubes, it was hypothesized that nanoparticles of inorganic compounds with layered (two-dimensional) structure, such as MoS(2), will not be stable against folding and form nanotubes and fullerene-like structures: IF. The synthesis of numerous other inorganic nanotubes has been reported in recent years. Various techniques for the synthesis of inorganic nanotubes, including high-temperature reactions and strategies based on 'chemie douce' (soft chemistry, i.e. low-temperature) processes, are described. First-principle, density functional theory based calculations are able to provide substantial information on the structure and properties of such nanotubes. Various properties of inorganic nanotubes, including mechanical, electronic and optical properties, are described in brief. Some potential applications of the nanotubes in tribology, protection against impact, (photo)catalysis, batteries, etc., are discussed.

[60]Fullerene Displacement from (Dihapto-Buckminster-Fullerene) Pentacarbonyl Tungsten(0): An Experiment for the Inorganic Chemistry Laboratory, Part II

ERIC Educational Resources Information Center

Cortes-Figueroa, Jose E.; Moore-Russo, Deborah A.

2006-01-01

The kinetics experiments on the ligand-C[subscript 60] exchange reactions on (dihapto-[60]fullerene) pentacarbonyl tungsten(0), ([eta][superscript 2]-C[subscript 60])W(CO)[subscript 5], form an educational activity for the inorganic chemistry laboratory that promotes graphical thinking as well as the understanding of kinetics, mechanisms, and the…

Interactions of Native Cyclodextrins with Metal Ions and Inorganic Nanoparticles: Fertile Landscape for Chemistry and Materials Science.

PubMed

Prochowicz, Daniel; Kornowicz, Arkadiusz; Lewiński, Janusz

2017-11-22

Readily available cyclodextrins (CDs) with an inherent hydrophobic internal cavity and hydrophilic external surface are macrocyclic entities that display a combination of molecular recognition and complexation properties with vital implications for host-guest supramolecular chemistry. While the host-guest chemistry of CDs has been widely recognized and led to their exploitation in a variety of important functions over the last five decades, these naturally occurring macrocyclic systems have emerged only recently as promising macrocyclic molecules to fabricate environmentally benign functional nanomaterials. This review surveys the development in the field paying special attention to the synthesis and emerging uses of various unmodified CD-metal complexes and CD-inorganic nanoparticle systems and identifies possible future directions. The association of a hydrophobic cavity of CDs with metal ions or various inorganic nanoparticles is a very appealing strategy for controlling the inorganic subunits properties in the very competitive water environment. In this review we provide the most prominent examples of unmodified CDs' inclusion complexes with organometallic guests and update the research in this field from the past decade. We discuss also the coordination flexibility of native CDs to metal ions in CD-based metal complexes and summarize the progress in the synthesis and characterization of CD-metal complexes and their use in catalysis and sensing as well as construction of molecular magnets. Then we provide a comprehensive overview of emerging applications of native CDs in materials science and nanotechnology. Remarkably, in the past few years CDs have appeared as attractive building units for the synthesis of carbohydrate metal-organic frameworks (CD-MOFs) in a combination of alkali-metal cations. The preparation of this new class of highly porous materials and their applications in the separation of small molecules, the loading of drug molecules, as well as

Chemistry of electronic ceramic materials. Proceedings of the International Conference on the Chemistry of Electronic Ceramic Materials

NASA Technical Reports Server (NTRS)

Davies, P. K.; Roth, R. S.

1991-01-01

The conference was held at Jackson Hole, Wyoming from August 17 to 22, 1990, and in an attempt to maximize the development of this rapidly moving, multidisciplinary field, this conference brought together major national and international researchers to bridge the gap between those primarily interested in the pure chemistry of inorganic solids and those interested in the physical and electronic properties of ceramics. With the many major discoveries that have occurred over the last decade, one of the goals of this meeting was to evaluate the current understanding of the chemistry of electronic ceramic materials, and to assess the state of a field that has become one of the most important areas of advanced materials research. The topics covered include: crystal chemistry; dielectric ceramics; low temperature synthesis and characterization; solid state synthesis and characterization; surface chemistry; superconductors; theory and modeling.

NUCLEAR CHEMISTRY ANNUAL REPORT 1970

DOE Office of Scientific and Technical Information (OSTI.GOV)

Authors, Various

Papers are presented for the following topics: (1) Nuclear Structure and Nuclear Properties - (a) Nuclear Spectroscopy and Radioactivity; (b) Nuclear Reactions and Scattering; (c) Nuclear Theory; and (d) Fission. (2) Chemical and Atomic Physics - (a) Atomic and Molecular Spectroscopy; and (b) Hyperfine Interactions. (3) Physical, Inorganic, and Analytical Chemistry - (a) X-Ray Crystallography; (b) Physical and Inorganic Chemistry; (c) Radiation Chemistry; and (d) Chemical Engineering. (4) Instrumentation and Systems Development.

Photoelectron Spectroscopy in Advanced Placement Chemistry

ERIC Educational Resources Information Center

Benigna, James

2014-01-01

Photoelectron spectroscopy (PES) is a new addition to the Advanced Placement (AP) Chemistry curriculum. This article explains the rationale for its inclusion, an overview of how the PES instrument records data, how the data can be analyzed, and how to include PES data in the course. Sample assessment items and analysis are included, as well as…

Zinc complexes developed as metallopharmaceutics for treating diabetes mellitus based on the bio-medicinal inorganic chemistry.

PubMed

Yoshikawa, Yutaka; Yasui, Hiroyuki

2012-01-01

Biological trace metals such as iron, zinc, copper, and manganese are essential to life and health of humans, and the success of platinum drugs in the cancer chemotherapy has rapidly grown interest in developing inorganic pharmaceutical agents in medicinal chemistry, that is, medicinal inorganic chemistry, using essential elements and other biological trace metals. Transition metal complexes with unique chemical structures may be useful alternatives to the drugs available to address some of the incurable diseases. In this review, we emphasize that metal complexes are an expanding of interest in the research field of treatment of diabetes mellitus. Especially, orally active anti-diabetic and anti-metabolic syndrome zinc complexes have been developed and progressed since the discovery in 2001, where several highly potent anti-diabetic zinc complexes with different coordination structures have quite recently been disclosed, using experimental diabetic animals. In all of the complexes discussed, zinc is found to be biologically active and function by interacting with some target proteins related with diabetes mellitus. The design and screening of zinc complexes with higher activity is not efficient without consideration of the translational research. For the development of a clinically useful metallopharmaceutics, the research of zinc complexes on the long-term toxicity including side effects, clear-cut evidence of target molecule for the in vivo pharmacological action, and good pharmacokinetic property are essential in the current and future studies.

Redox-responsive theranostic nanoplatforms based on inorganic nanomaterials.

PubMed

Han, Lu; Zhang, Xiao-Yong; Wang, Yu-Long; Li, Xi; Yang, Xiao-Hong; Huang, Min; Hu, Kun; Li, Lu-Hai; Wei, Yen

2017-08-10

Spurred on by advances in materials chemistry and nanotechnology, scientists have developed many novel nanopreparations for cancer diagnosis and therapy. To treat complex malignant tumors effectively, multifunctional nanomedicines with targeting ability, imaging properties and controlled drug release behavior should be designed and exploited. The therapeutic efficiency of loaded drugs can be dramatically improved using redox-responsive nanoplatforms which can sense the differences in the redox status of tumor tissues and healthy ones. Redox-sensitive nanocarriers can be constructed from both organic and inorganic nanomaterials; however, at present, drug delivery nanovectors progressively lean towards inorganic nanomaterials because of their facile synthesis/modification and their unique physicochemical properties. In this review, we focus specifically on the preparation and application of redox-sensitive nanosystems based on mesoporous silica nanoparticles (MSNs), carbon nanomaterials, magnetic nanoparticles, gold nanomaterials and other inorganic nanomaterials. We discuss relevant examples of redox-sensitive nanosystems in each category. Finally, we discuss current challenges and future strategies from the aspect of material design and practical application. Copyright © 2017 Elsevier B.V. All rights reserved.

Recent Advances in Inorganic Heterogeneous Electrocatalysts for Reduction of Carbon Dioxide.

PubMed

Zhu, Dong Dong; Liu, Jin Long; Qiao, Shi Zhang

2016-05-01

In view of the climate changes caused by the continuously rising levels of atmospheric CO2 , advanced technologies associated with CO2 conversion are highly desirable. In recent decades, electrochemical reduction of CO2 has been extensively studied since it can reduce CO2 to value-added chemicals and fuels. Considering the sluggish reaction kinetics of the CO2 molecule, efficient and robust electrocatalysts are required to promote this conversion reaction. Here, recent progress and opportunities in inorganic heterogeneous electrocatalysts for CO2 reduction are discussed, from the viewpoint of both experimental and computational aspects. Based on elemental composition, the inorganic catalysts presented here are classified into four groups: metals, transition-metal oxides, transition-metal chalcogenides, and carbon-based materials. However, despite encouraging accomplishments made in this area, substantial advances in CO2 electrolysis are still needed to meet the criteria for practical applications. Therefore, in the last part, several promising strategies, including surface engineering, chemical modification, nanostructured catalysts, and composite materials, are proposed to facilitate the future development of CO2 electroreduction. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Goldilocks and the three inorganic equilibria: how Earth's chemistry and life coevolve to be nearly in tune.

PubMed

Rickaby, R E M

2015-03-13

Life and the chemical environment are united in an inescapable feedback cycle. The periodic table of the elements essential for life has transformed over Earth's history, but, as today, evolved in tune with the elements available in abundance in the environment. The most revolutionary time in life's history was the advent and proliferation of oxygenic photosynthesis which forced the environment towards a greater degree of oxidation. Consideration of three inorganic chemical equilibria throughout this gradual oxygenation prescribes a phased release of trace metals to the environment, which appear to have coevolved with employment of these new chemicals by life. Evolution towards complexity was chemically constrained, and changes in availability of notably Fe, Zn and Cu paced the systematic development of complex organisms. Evolving life repeatedly catalysed its own chemical challenges via the unwitting release of new and initially toxic chemicals. Ultimately, the harnessing of these allowed life to advance to greater complexity, though the mechanism responsible for translating novel chemistry to heritable use remains elusive. Whether a chemical acts as a poison or a nutrient lies both in the dose and in its environmental history. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Recent Advances in Azaborine Chemistry

PubMed Central

Campbell, Patrick G.; Marwitz, Adam J. V.

2013-01-01

The chemistry of organoboron compounds has been primarily dominated by their use as powerful reagents in synthetic organic chemistry. Recently, the incorporation of boron as part of a functional target structure has emerged as a useful way to generate diversity in organic compounds. A commonly applied strategy is the replacement of a CC unit with its isoelectronic BN unit. In particular, the BN/CC isosterism of the ubiquitous arene motif has undergone a renaissance in the past decade. The parent molecule of the 1,2-dihydro-1,2-azaborine family has now been isolated. New mono- and polycyclic BN heterocycles have been synthesized for potential use in biomedical and materials science applications. This review is a tribute to Dewar's first synthesis of a monocyclic 1,2-dihydro-1,2-azaborine 50 years ago and discusses recent advances in the synthesis and characterization of carbon(C)-boron(B)-nitrogen(N)-containing heterocycles. PMID:22644658

Methods for Introducing Inorganic Polymer Concepts throughout the Undergraduate Curriculum

ERIC Educational Resources Information Center

de Lill, Daniel T.; Carraher, Charles E., Jr.

2017-01-01

Inorganic polymers can be introduced in a variety of undergraduate courses to discuss concepts related to polymer chemistry. Inorganic polymers such as silicates and polysiloxanes are simple materials that can be incorporated into an introductory or descriptive inorganic course. Polymers based on inorganic carbon, including diamond and graphite,…

Development and Application of a Two-Tier Multiple Choice Diagnostic Instrument To Assess High School Students' Understanding of Inorganic Chemistry Qualitative Analysis.

ERIC Educational Resources Information Center

Tan, Kim Chwee Daniel; Goh, Ngoh Khang; Chia, Lian Sai; Treagust, David F.

2002-01-01

Describes the development and application of a two-tier multiple choice diagnostic instrument to assess high school students' understanding of inorganic chemistry qualitative analysis. Shows that the Grade 10 students had difficulty understanding the reactions involved in the identification of cations and anions, for example, double decomposition…

Nuclear chemistry. Annual report, 1974

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conzett, H.E.; Edelstein, N.M.; Tsang, C.F.

1975-07-01

The 1974 Nuclear Chemistry Annual Report contains information on research in the following areas: nuclear science (nuclear spectroscopy and radioactivity, nuclear reactions and scattering, nuclear theory); chemical and atomic physics (heavy ion-induced atomic reactions, atomic and molecular spectroscopy, photoelectron spectroscopy and hyperfine interactions); physical, inorganic, and analytical chemistry (x-ray crystallography, physical and inorganic chemistry, geochemistry); and instrumentation. Thesis abstracts, 1974 publication titles, and an author index are also included. Papers having a significant amount of information are listed separately by title. (RWR)

Diversity and Periodicity: An Inorganic Chemistry Module.

ERIC Educational Resources Information Center

Huheey, James

This book is one in a series of Interdisciplinary Approaches to Chemistry (IAC) designed to help students discover that chemistry is a lively science and actively used to pursue solutions to the important problems of today. It is expected for students to see how chemistry takes place continuously all around and to readily understand the daily…

Advances on Aryldiazonium Salt Chemistry Based Interfacial Fabrication for Sensing Applications.

PubMed

Cao, Chaomin; Zhang, Yin; Jiang, Cheng; Qi, Meng; Liu, Guozhen

2017-02-15

Aryldiazonium salts as coupling agents for surface chemistry have evidenced their wide applications for the development of sensors. Combined with advances in nanomaterials, current trends in sensor science and a variety of particular advantages of aryldiazonium salt chemistry in sensing have driven the aryldiazonium salt-based sensing strategies to grow at an astonishing pace. This review focuses on the advances in the use of aryldiazonium salts for modifying interfaces in sensors and biosensors during the past decade. It will first summarize the current methods for modification of interfaces with aryldiazonium salts, and then discuss the sensing applications of aryldiazonium salts modified on different transducers (bulky solid electrodes, nanomaterials modified bulky solid electrodes, and nanoparticles). Finally, the challenges and perspectives that aryldiazonium salt chemistry is facing in sensing applications are critically discussed.

An Integrated Curriculum for First- and Second-Year Chemistry Courses

NASA Astrophysics Data System (ADS)

Rettich, T. R.; Bailey, David N.; Frank, Forrest J.; Frick, Jeffrey A.

1996-07-01

The chemistry department at Illinois Wesleyan University is revising its freshman and sophomore sequence as outlined earlier in this Journal (1). Key features of this innovation are the integration of organic and inorganic chemical concepts throughout the first two years of the curriculum, the incorporation of modern instrumentation into lecture and laboratory beginning the first semester, and the matching of topic development to student ability throughout the two-year sequence. We believe the proposed curriculum has unique advantages in comparison to the traditional, the organic first, and the two-cycle approaches. A student whose only college-level experience with molecular science is traditional general chemistry sees a very isolated view of the subject: a view long on theory and quantitative problem solving, but short on those qualitative skills, life science applications, and hands-on use of advanced chemical instrumentation typically found in organic chemistry. Those programs that put organic first, either as a full year or as part of a two-cycle approach, have the advantage of introducing new topics to college freshmen with an adequate high school chemistry background. But merely shuffling the order of the first four traditional semesters of college chemistry simply exchanges one set of problems for another. Segregating inorganic and organic topics according to semesters means that the most advanced inorganic (or organic) chemical concepts are usually presented in the second semester (or possibly the third semester with a two-cycle approach). Even very capable students who successfully complete such a four-semester program will often view chemistry as disjointed; that is, the sophomore organic chemistry class is seen neither as a logical continuation of nor as a development based upon the first year's experience. The first two years of college chemistry are perceived by most students, and often treated by faculty, as distinct entities. The two courses are

Great expectations: using an analysis of current practices to propose a framework for the undergraduate inorganic curriculum.

PubMed

Reisner, Barbara A; Smith, Sheila R; Stewart, Joanne L; Raker, Jeffrey R; Crane, Johanna L; Sobel, Sabrina G; Pesterfield, Lester L

2015-09-21

The undergraduate inorganic chemistry curriculum in the United States mirrors the broad diversity of the inorganic research community and poses a challenge for the development of a coherent curriculum that is thorough, rigorous, and engaging. A recent large survey of the inorganic community has provided information about the current organization and content of the inorganic curriculum from an institutional level. The data reveal shared "core" concepts that are broadly taught, with tremendous variation in content coverage beyond these central ideas. The data provide an opportunity for a community-driven discussion about how the American Chemical Society's Committee on Professional Training's vision of a foundation and in-depth course for each of the five subdisciplines maps onto an inorganic chemistry curriculum that is consistent in its coverage of the core inorganic concepts, yet reflects the diversity and creativity of the inorganic community. The goal of this Viewpoint is to present the current state of the diverse undergraduate curriculum and lay a framework for an effective and engaging curriculum that illustrates the essential role inorganic chemistry plays within the chemistry community.

Research for the advancement of green chemistry practice: Studies in atmospheric and educational chemistry

NASA Astrophysics Data System (ADS)

Cullipher, Steven Gene

Green chemistry is a philosophy of chemistry that emphasizes a decreasing dependence on limited non-renewable resources and an increasing focus on preventing pollution byproducts of the chemical industry. In short, it is the discipline of chemistry practiced through the lens of environmental stewardship. In an effort to advance the practice of green chemistry, three studies will be described that have ramifications for the practice. The first study examines the atmospheric oxidation of a hydrofluorinated ether, a third-generation CFC replacement compound with primarily unknown atmospheric degradation products. Determination of these products has the potential to impact decisions on refrigerant usage in the future. The second study examines chemistry students' development of understanding benefits-costs-risks analysis when presented with two real-world scenarios: refrigerant choice and fuel choice. By studying how benefits-costs-risks thinking develops, curricular materials and instructional approaches can be designed to better foster the development of an ability that is both necessary for green chemists and important in daily decision-making for non-chemists. The final study uses eye tracking technology to examine students' abilities to interpret molecular properties from structural information in the context of global warming. Such abilities are fundamental if chemists are to appropriately assess risks and hazards of chemistry practice.

Advances in analytical chemistry

NASA Technical Reports Server (NTRS)

Arendale, W. F.; Congo, Richard T.; Nielsen, Bruce J.

1991-01-01

Implementation of computer programs based on multivariate statistical algorithms makes possible obtaining reliable information from long data vectors that contain large amounts of extraneous information, for example, noise and/or analytes that we do not wish to control. Three examples are described. Each of these applications requires the use of techniques characteristic of modern analytical chemistry. The first example, using a quantitative or analytical model, describes the determination of the acid dissociation constant for 2,2'-pyridyl thiophene using archived data. The second example describes an investigation to determine the active biocidal species of iodine in aqueous solutions. The third example is taken from a research program directed toward advanced fiber-optic chemical sensors. The second and third examples require heuristic or empirical models.

Organic chemistry on solid surfaces

NASA Astrophysics Data System (ADS)

Ma, Zhen; Zaera, Francisco

2006-07-01

Chemistry on solid surfaces is central to many areas of practical interest such as heterogeneous catalysis, tribology, electrochemistry, and materials processing. With the development of many surface-sensitive analytical techniques in the past decades, great advances have been possible in our understanding of such surface chemistry at the molecular level. Earlier studies with model systems, single crystals in particular, have provided rich information about the adsorption and reaction kinetics of simple inorganic molecules. More recently, the same approach has been expanded to the study of the surface chemistry of relatively complex organic molecules, in large measure in connection with the selective synthesis of fine chemicals and pharmaceuticals. In this report, the chemical reactions of organic molecules and fragments on solid surfaces, mainly on single crystals of metals but also on crystals of metal oxides, carbides, nitrides, phosphides, sulfides and semiconductors as well as on more complex models such as bimetallics, alloys, and supported particles, are reviewed. A scheme borrowed from the organometallic and organic chemistry literature is followed in which key examples of representative reactions are cited first, and general reactivity trends in terms of both the reactants and the nature of the surface are then identified to highlight important mechanistic details. An attempt has been made to emphasize recent advances, but key earlier examples are cited as needed. Finally, correlations between surface and organometallic and organic chemistry, the relevance of surface reactions to applied catalysis and materials functionalization, and some promising future directions in this area are briefly discussed.

Integration of a Communicating Science Module into an Advanced Chemistry Laboratory Course

ERIC Educational Resources Information Center

Renaud, Jessica; Squier, Christopher; Larsen, Sarah C.

2006-01-01

A communicating science module was introduced into an advanced undergraduate physical chemistry laboratory course. The module was integrated into the course such that students received formal instruction in communicating science interwoven with the chemistry laboratory curriculum. The content of the communicating science module included three…

Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise.

PubMed

Rapp, Teresa L; Phillips, Susan R; Dmochowski, Ivan J

2016-12-13

The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, light-driven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes that provide a sterically bulky, photolabile moiety for transiently "caging" biologically active molecules. Photouncaging involves the use of visible (1-photon) or near-IR (2-photon) light to break one or more bonds between ruthenium and coordinated ligand(s), which can occur on short time scales and in high quantum yields. In this work we demonstrate the use of a model "caged" acetonitrile complex, Ru(2,2'-bipyridine) 2 (acetonitrile) 2 , or RuMeCN in an advanced synthesis and physical chemistry laboratory. Students made RuMeCN in an advanced synthesis laboratory course and performed UV-vis spectroscopy and electrochemistry. The following semester students investigated RuMeCN photolysis kinetics in a physical chemistry laboratory. These two exercises may also be combined to create a 2-week module in an advanced undergraduate laboratory course.

Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

PubMed Central

2016-01-01

The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, light-driven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes that provide a sterically bulky, photolabile moiety for transiently “caging” biologically active molecules. Photouncaging involves the use of visible (1-photon) or near-IR (2-photon) light to break one or more bonds between ruthenium and coordinated ligand(s), which can occur on short time scales and in high quantum yields. In this work we demonstrate the use of a model “caged” acetonitrile complex, Ru(2,2′-bipyridine)2(acetonitrile)2, or RuMeCN in an advanced synthesis and physical chemistry laboratory. Students made RuMeCN in an advanced synthesis laboratory course and performed UV–vis spectroscopy and electrochemistry. The following semester students investigated RuMeCN photolysis kinetics in a physical chemistry laboratory. These two exercises may also be combined to create a 2-week module in an advanced undergraduate laboratory course. PMID:28649139

Development of an Advanced Training Course for Teachers and Researchers in Chemistry

ERIC Educational Resources Information Center

Dragisich, Vera; Keller, Valerie; Black, Rebecca; Heaps, Charles W.; Kamm, Judith M.; Olechnowicz, Frank; Raybin, Jonathan; Rombola, Michael; Zhao, Meishan

2016-01-01

Based on our long-standing Intensive Training Program for Effective Teaching Assistants in Chemistry, we have developed an Advanced Training Course for Teachers and Researchers in Chemistry at The University of Chicago. The topics in this course are designed to train graduate teaching assistants (GTAs) to become effective teachers and well-rounded…

21 CFR 862.1580 - Phosphorus (inorganic) test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Phosphorus (inorganic) test system. 862.1580 Section 862.1580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

The Birthday of Organic Chemistry.

ERIC Educational Resources Information Center

Benfey, Otto Theodor; Kaufman, George B.

1979-01-01

Describes how the synthesis of urea, 150 years ago, was a major factor in breaking the artificial barrier that existed between organic and inorganic chemistry, and this contributed to the rapid growth of organic chemistry. (GA)

Metalloporphyrins as Oxidation Catalysts: Moving toward "Greener" Chemistry in the Inorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Clark, Rose A.; Stock, Anne E.; Zovinka, Edward P.

2012-01-01

Training future chemists to be aware of the environmental impact of their work is of fundamental importance to global society. To convince chemists to embrace sustainability, the integration of green chemistry across the entire chemistry curriculum is a necessary step. This experiment expands the reach of green chemistry techniques into the…

A Multiweek Upper-Division Inorganic Laboratory Based on Metallacrowns

ERIC Educational Resources Information Center

Sirovetz, Brian J.; Walters, Nicole E.; Bender, Collin N.; Lenivy, Christopher M.; Troup, Anna S.; Predecki, Daniel P.; Richardson, John N.; Zaleski, Curtis M.

2013-01-01

Metallacrowns are a versatile class of inorganic compounds with uses in several areas of chemistry. Students engage in a multiweek, upper-division inorganic laboratory that explores four different metallacrown compounds: Fe[superscript III](O[subscript 2]CCH[subscript 3])[subscript 3][9-MC[subscript Fe][superscript III][subscript…

A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

NASA Technical Reports Server (NTRS)

Reid, Concha M.; Bennett, William R.

2010-01-01

NASAs Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair Lunar Lander and the Extravehicular Activities (EVA) advanced Lunar surface spacesuit. These customers require safe, reliable batteries with extremely high specific energy as compared to state-of-the-art. The specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery-level at 0 degrees Celsius ( C) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation between 0 and 30 C and 200 cycles are targeted. Electrode materials that were considered include layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. Advanced cell chemistry options were evaluated with respect to multiple quantitative and qualitative attributes while considering their projected performance at the end of the available development timeframe. Following a rigorous ranking process, a chemistry that combines a lithiated nickel manganese cobalt oxide Li(LiNMC)O2 cathode with a silicon-based composite anode was selected as the technology that can potentially offer the best combination of safety, specific energy, energy density, and likelihood of success.

Inorganic Analyses in Water Quality Control Programs. Training Manual.

ERIC Educational Resources Information Center

Kroner, Audrey; And Others

This lecture/laboratory manual for a five-day course deals with the analysis of selected inorganic pollutants. The manual is an instructional aid for classroom presentations to those with little or no experience in the field, but having one year (or equivalent) of college level inorganic chemistry, one semester of college level quantitative…

Inorganic Analyses in Water Quality Control Programs. Training Manual.

ERIC Educational Resources Information Center

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

This document is a lecture/laboratory manual dealing with the analysis of selected inorganic pollutants. The manual is an instructional aid for classroom presentations to those with little or no experience in the field, but having one year (or equivalent) of college level inorganic chemistry and having basic laboratory skills. Topics include:…

Growth, characterization and post-processing of inorganic and hybrid organic-inorganic thin films deposited using atomic and molecular layer deposition techniques

NASA Astrophysics Data System (ADS)

Abdulagatov, Aziz Ilmutdinovich

Atomic layer deposition (ALD) and molecular layer deposition (MLD) are advanced thin film coating techniques developed for deposition of inorganic and hybrid organic-inorganic films respectively. Decreasing device dimensions and increasing aspect ratios in semiconductor processing has motivated developments in ALD. The beginning of this thesis will cover study of new ALD chemistry for high dielectric constant Y 2O3. In addition, the feasibility of conducting low temperature ALD of TiN and TiAlN is explored using highly reactive hydrazine as a new nitrogen source. Developments of these ALD processes are important for the electronics industry. As the search for new materials with more advanced properties continues, attention has shifted toward exploring the synthesis of hierarchically nanostructured thin films. Such complex architectures can provide novel functions important to the development of state of the art devices for the electronics industry, catalysis, energy conversion and memory storage as a few examples. Therefore, the main focus of this thesis is on the growth, characterization, and post-processing of ALD and MLD films for fabrication of novel composite (nanostructured) thin films. Novel composite materials are created by annealing amorphous ALD oxide alloys in air and by heat treatment of hybrid organic-inorganic MLD films in inert atmosphere (pyrolysis). The synthesis of porous TiO2 or Al2O3 supported V2O5 for enhanced surface area catalysis was achieved by the annealing of inorganic TiVxOy and AlV xOy ALD films in air. The interplay between phase separation, surface energy difference, crystallization, and melting temperature of individual oxides were studied for their control of film morphology. In other work, a class of novel metal oxide-graphitic carbon composite thin films was produced by pyrolysis of MLD hybrid organic-inorganic films. For example, annealing in argon of titania based hybrid films enabled fabrication of thin films of intimately

An Undergraduate Laboratory Experiment in Bioinorganic Chemistry: Ligation States of Myoglobin

ERIC Educational Resources Information Center

Bailey, James A.

2011-01-01

Although there are numerous inorganic model systems that are readily presented as undergraduate laboratory experiments in bioinorganic chemistry, there are few examples that explore the inorganic chemistry of actual biological molecules. We present a laboratory experiment using the oxygen-binding protein myoglobin that can be easily incorporated…

Halogen Chemistry in the CMAQ Model

EPA Science Inventory

Halogens (iodine and bromine) emitted from oceans alter atmospheric chemistry and influence atmospheric ozone mixing ratio. We previously incorporated a representation of detailed halogen chemistry and emissions of organic and inorganic halogen species into the hemispheric Commun...

Inkjet printing for biosensor fabrication: combining chemistry and technology for advanced manufacturing.

PubMed

Li, Jia; Rossignol, Fabrice; Macdonald, Joanne

2015-06-21

Inkjet printing is emerging at the forefront of biosensor fabrication technologies. Parallel advances in both ink chemistry and printers have led to a biosensor manufacturing approach that is simple, rapid, flexible, high resolution, low cost, efficient for mass production, and extends the capabilities of devices beyond other manufacturing technologies. Here we review for the first time the factors behind successful inkjet biosensor fabrication, including printers, inks, patterning methods, and matrix types. We discuss technical considerations that are important when moving beyond theoretical knowledge to practical implementation. We also highlight significant advances in biosensor functionality that have been realised through inkjet printing. Finally, we consider future possibilities for biosensors enabled by this novel combination of chemistry and technology.

A Multistep Synthesis for an Advanced Undergraduate Organic Chemistry Laboratory

ERIC Educational Resources Information Center

Chang Ji; Peters, Dennis G.

2006-01-01

Multistep syntheses are often important components of the undergraduate organic laboratory experience and a three-step synthesis of 5-(2-sulfhydrylethyl) salicylaldehyde was described. The experiment is useful as a special project for an advanced undergraduate organic chemistry laboratory course and offers opportunities for students to master a…

Assessing Advanced High School and Undergraduate Students' Thinking Skills: The Chemistry--From the Nanoscale to Microelectronics Module

ERIC Educational Resources Information Center

Dori, Yehudit Judy; Dangur, Vered; Avargil, Shirly; Peskin, Uri

2014-01-01

Chemistry students in Israel have two options for studying chemistry: basic or honors (advanced placement). For instruction in high school honors chemistry courses, we developed a module focusing on abstract topics in quantum mechanics: Chemistry--From the Nanoscale to Microelectronics. The module adopts a visual-conceptual approach, which…

Integrating Project-Based Service-Learning into an Advanced Environmental Chemistry Course

ERIC Educational Resources Information Center

Draper, Alison J.

2004-01-01

An active service-learning research work is conducted in the field of advanced environmental chemistry. Multiple projects are assigned to students, which promote individual learning skills, self-confidence as scientists, and a deep understanding of the environmental chemist's profession.

Infrared Spectrometry of Inorganic Salts

ERIC Educational Resources Information Center

Ackermann, Martin N.

1970-01-01

Describes a general chemistry experiment which uses infrared spectroscopy to analyze inorganic ions and thereby serves to introduce an important instrumental method of analysis. Presents a table of eight anions and the ammonium ion with the frequencies of their normal modes, as well as the spectra of three sulfate salts. (RR)

Synthesis and Characterization of Europium(III) and Terbium(III) Complexes: An Advanced Undergraduate Inorganic Chemistry Experiment

ERIC Educational Resources Information Center

Swavey, Shawn

2010-01-01

Undergraduate laboratories rarely involve lanthanide coordination chemistry. This is unfortunate in light of the ease with which many of these complexes are made and the interesting and instructive photophysical properties they entail. The forbidden nature of the 4f transitions associated with the lanthanides is overcome by incorporation of…

Inorganic dendrimers: recent advances for catalysis, nanomaterials, and nanomedicine.

PubMed

Caminade, Anne-Marie

2016-10-07

Dendrimers are hyperbranched polymers having a perfectly defined structure because they are synthesized step-by-step in an iterative fashion, and not by polymerization reactions. Some dendrimers are considered as inorganic, as they possess inorganic atoms at each branching point. Among numerous examples, two families of inorganic dendrimers have emerged as particularly promising: silicon-containing dendrimers, particularly carbosilanes, and phosphorus-containing dendrimers, particularly phosphorhydrazones. This tutorial review will display the main properties of both families of dendrimers in the fields of catalysis, materials and biology/nanomedicine. Emphasis will be put on the most recent and promising examples.

All-inorganic Germanium nanocrystal films by cationic ligand exchange

DOE PAGES

Wheeler, Lance M.; Nichols, Asa W.; Chernomordik, Boris D.; ...

2016-01-21

In this study, we introduce a new paradigm for group IV nanocrystal surface chemistry based on room temperature surface activation that enables ionic ligand exchange. Germanium nanocrystals synthesized in a gas-phase plasma reactor are functionalized with labile, cationic alkylammonium ligands rather than with traditional covalently bound groups. We employ Fourier transform infrared and 1H nuclear magnetic resonance spectroscopies to demonstrate the alkylammonium ligands are freely exchanged on the germanium nanocrystal surface with a variety of cationic ligands, including short inorganic ligands such as ammonium and alkali metal cations. This ionic ligand exchange chemistry is used to demonstrate enhanced transport inmore » germanium nanocrystal films following ligand exchange as well as the first photovoltaic device based on an all-inorganic germanium nanocrystal absorber layer cast from solution. This new ligand chemistry should accelerate progress in utilizing germanium and other group IV nanocrystals for optoelectronic applications.« less

An Advanced Undergraduate Chemistry Laboratory Experiment Exploring NIR Spectroscopy and Chemometrics

ERIC Educational Resources Information Center

Wanke, Randall; Stauffer, Jennifer

2007-01-01

An advanced undergraduate chemistry laboratory experiment to study the advantages and hazards of the coupling of NIR spectroscopy and chemometrics is described. The combination is commonly used for analysis and process control of various ingredients used in agriculture, petroleum and food products.

Potential Role of Inorganic Confined Environments in Prebiotic Phosphorylation.

PubMed

Dass, Avinash Vicholous; Jaber, Maguy; Brack, André; Foucher, Frédéric; Kee, Terence P; Georgelin, Thomas; Westall, Frances

2018-03-05

A concise outlook on the potential role of confinement in phosphorylation and phosphate condensation pertaining to prebiotic chemistry is presented. Inorganic confinement is a relatively uncharted domain in studies concerning prebiotic chemistry, and even more so in terms of experimentation. However, molecular crowding within confined dimensions is central to the functioning of contemporary biology. There are numerous advantages to confined environments and an attempt to highlight this fact, within this article, has been undertaken, keeping in context the limitations of aqueous phase chemistry in phosphorylation and, to a certain extent, traditional approaches in prebiotic chemistry.

Techniques in Chemistry: The Centerpiece of a Research-Oriented Curriculum.

ERIC Educational Resources Information Center

Hanks, T. W.; Wright, Laura L.

2002-01-01

Introduces the Techniques in Chemistry I course taught in the Furman University Department of Chemistry which focuses on organic and inorganic chemistry. Uses a problem solving approach and active learning. (Contains 17 references.) (YDS)

Recent Advances on Inorganic Nanoparticle-Based Cancer Therapeutic Agents

PubMed Central

Wang, Fenglin; Li, Chengyao; Cheng, Jing; Yuan, Zhiqin

2016-01-01

Inorganic nanoparticles have been widely investigated as therapeutic agents for cancer treatments in biomedical fields due to their unique physical/chemical properties, versatile synthetic strategies, easy surface functionalization and excellent biocompatibility. This review focuses on the discussion of several types of inorganic nanoparticle-based cancer therapeutic agents, including gold nanoparticles, magnetic nanoparticles, upconversion nanoparticles and mesoporous silica nanoparticles. Several cancer therapy techniques are briefly introduced at the beginning. Emphasis is placed on how these inorganic nanoparticles can provide enhanced therapeutic efficacy in cancer treatment through site-specific accumulation, targeted drug delivery and stimulated drug release, with elaborations on several examples to highlight the respective strategies adopted. Finally, a brief summary and future challenges are included. PMID:27898016

Recent Advances on Inorganic Nanoparticle-Based Cancer Therapeutic Agents.

PubMed

Wang, Fenglin; Li, Chengyao; Cheng, Jing; Yuan, Zhiqin

2016-11-25

Inorganic nanoparticles have been widely investigated as therapeutic agents for cancer treatments in biomedical fields due to their unique physical/chemical properties, versatile synthetic strategies, easy surface functionalization and excellent biocompatibility. This review focuses on the discussion of several types of inorganic nanoparticle-based cancer therapeutic agents, including gold nanoparticles, magnetic nanoparticles, upconversion nanoparticles and mesoporous silica nanoparticles. Several cancer therapy techniques are briefly introduced at the beginning. Emphasis is placed on how these inorganic nanoparticles can provide enhanced therapeutic efficacy in cancer treatment through site-specific accumulation, targeted drug delivery and stimulated drug release, with elaborations on several examples to highlight the respective strategies adopted. Finally, a brief summary and future challenges are included.

FORUM: Bioinspired Heme, Heme/non-heme Diiron, Heme/copper and Inorganic NOx Chemistry: ·NO(g) Oxidation, Peroxynitrite-Metal Chemistry and ·NO(g) Reductive Coupling

PubMed Central

Schopfer, Mark P.; Wang, Jun; Karlin, Kenneth D.

2010-01-01

The focus of this Forum review highlights work from our own laboratories and those of others in the area of biochemical and biologically inspired inorganic chemistry dealing with nitric oxide (nitrogen monoxide, ·NO(g)) and its biological roles and reactions. The latter focus is on (i) oxidation of ·NO(g) to nitrate by nitric oxide dioxygenases (NOD’s), and (ii) reductive coupling of two molecules of ·NO(g) to give N2O(g). In the former case, NOD’s are described and the highlighting of possible peroxynitrite-heme intermediates and consequences of this are given by discussion of recent works with myoglobin and a synthetic heme model system for NOD action. Summaries of recent copper complex chemistries with ·NO(g) and O2(g) leading to peroxynitrite species are given. The coverage of biological reductive coupling of ·NO(g) deals with bacterial nitric oxide reductases (NOR’s) with heme/non-heme diiron active sites, and on heme/Cu oxidases such as cytochrome c oxidase which can mediate the same chemistry. Recent designed protein and synthetic model compound (heme/non-heme diiron or heme/copper) as functional mimics are discussed in some detail. We also highlight examples from the chemical literature, not necessarily involving biologically relevant metal ions, which describe the oxidation of ·NO(g) to nitrate (or nitrite) and possible peroxynitrite intermediates, or reductive coupling of ·NO(g) to give nitrous oxide. PMID:20666386

Polynitrogen Chemistry

DTIC Science & Technology

2013-09-24

pentadienide anion and one could envision a wealth of inorganic ferrocene -type chemistry using cyclo-N5 - . Although several dozen theoretical...publications have predicted the stability of such ferrocene analogues, the bulk synthesis of an N5 - salt has not been realized so far. 6,7 Similarly, the

Apoc Social: A Mobile Interactive and Social Learning Platform for Collaborative Solving of Advanced Problems in Organic Chemistry.

PubMed

Sievertsen, Niels; Carreira, Erick M

2018-02-01

Mobile devices such as smartphones are carried in the pockets of university students around the globe and are increasingly cheap to come by. These portable devices have evolved into powerful and interconnected handheld computers, which, among other applications, can be used as advanced learning tools and providers of targeted, curated content. Herein, we describe Apoc Social (Advanced Problems in Organic Chemistry Social), a mobile application that assists both learning and teaching college-level organic chemistry both in the classroom and on the go. With more than 750 chemistry exercises available, Apoc Social facilitates collaborative learning through discussion boards and fosters enthusiasm for complex organic chemistry.

Potential Role of Inorganic Confined Environments in Prebiotic Phosphorylation

PubMed Central

Jaber, Maguy; Brack, André; Foucher, Frédéric; Kee, Terence P.; Westall, Frances

2018-01-01

A concise outlook on the potential role of confinement in phosphorylation and phosphate condensation pertaining to prebiotic chemistry is presented. Inorganic confinement is a relatively uncharted domain in studies concerning prebiotic chemistry, and even more so in terms of experimentation. However, molecular crowding within confined dimensions is central to the functioning of contemporary biology. There are numerous advantages to confined environments and an attempt to highlight this fact, within this article, has been undertaken, keeping in context the limitations of aqueous phase chemistry in phosphorylation and, to a certain extent, traditional approaches in prebiotic chemistry. PMID:29510574

Fluorometric method for inorganic pyrophosphatase activity detection and inhibitor screening based on click chemistry.

PubMed

Xu, Kefeng; Chen, Zhonghui; Zhou, Ling; Zheng, Ou; Wu, Xiaoping; Guo, Longhua; Qiu, Bin; Lin, Zhenyu; Chen, Guonan

2015-01-06

A fluorometric method for pyrophosphatase (PPase) activity detection was developed based on click chemistry. Cu(II) can coordinate with pyrophosphate (PPi), the addition of pyrophosphatase (PPase) into the above system can destroy the coordinate compound because PPase catalyzes the hydrolysis of PPi into inorganic phosphate and produces free Cu(II), and free Cu(II) can be reduced by sodium ascorbate (SA) to form Cu(I), which in turn initiates the ligating reaction between nonfluorescent 3-azidocoumarins and terminal alkynes to produce a highly fluorescent triazole complex, based on which, a simple and sensitive turn on fluorometric method for PPase can be developed. The fluorescence intensity of the system has a linear relationship with the logarithm of the PPase concentration in the range of 0.5 and 10 mU with a detection limit down to 0.2 mU (S/N = 3). This method is cost-effective and convenient without any labels or complicated operations. The proposed system was applied to screen the potential PPase inhibitor with high efficiency. The proposed method can be applied to diagnosis of PPase-related diseases.

Hydrocarbons. Independent Learning Project for Advanced Chemistry (ILPAC). Unit O1.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on hydrocarbons is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit is divided into sections dealing with alkanes, alkenes, alkynes, arenes, and several aspects of the petroleum industry. Two experiments, exercises (with answers), and pre- and post-tests are included.…

New Guidelines for Undergraduate Chemistry Curricula Examined.

ERIC Educational Resources Information Center

Worthy, Ward

1989-01-01

Reviews current biochemistry, education, and polymer course options found in chemistry programs. Proposes a new core curriculum with 28 semester hours with courses in inorganic, chemical, and instrumental analysis, organic, bioorganic, and physical chemistry. Notes that the new curriculum would better prepare students for the existing employment…

Independent Learning Project for Advanced Chemistry (ILPAC). Teachers' and Technicians' Notes for First Year Units.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

The Independent Learning Project for Advanced Chemistry (ILPAC) has produced units of study for students in A-level chemistry. Students completing ILPAC units assume a greater responsibility for their own learning and can work, to some extent, at their own pace. By providing guidance, and detailed solutions to exercises in the units, supported by…

Inorganic hydrogen polysulfides: chemistry, chemical biology and detection.

PubMed

Liu, Heng; Radford, Miles N; Yang, Chun-Tao; Chen, Wei; Xian, Ming

2018-04-18

Recent studies suggest that inorganic hydrogen polysulfides (H 2 S n , n ≥ 2) play important regulatory roles in redox biology. Modulation of their cellular levels could have potential therapeutic value. This review article focuses on our current understanding of the biosynthesis, biofunctions, fundamental physical/chemical properties, detection methods and delivery techniques of H 2 S n . © 2018 The British Pharmacological Society.

Chemistry WebBook

National Institute of Standards and Technology Data Gateway

SRD 69 NIST Chemistry WebBook (Web, free access)   The NIST Chemistry WebBook contains: Thermochemical data for over 7000 organic and small inorganic compounds; thermochemistry data for over 8000 reactions; IR spectra for over 16,000 compounds; mass spectra for over 33,000 compounds; UV/Vis spectra for over 1600 compounds; electronic and vibrational spectra for over 5000 compounds; constants of diatomic molecules(spectroscopic data) for over 600 compounds; ion energetics data for over 16,000 compounds; thermophysical property data for 74 fluids.

Synthesis of Well-Defined Copper "N"-Heterocyclic Carbene Complexes and Their Use as Catalysts for a "Click Reaction": A Multistep Experiment that Emphasizes the Role of Catalysis in Green Chemistry

ERIC Educational Resources Information Center

Ison, Elon A.; Ison, Ana

2012-01-01

A multistep experiment for an advanced synthesis lab course that incorporates topics in organic-inorganic synthesis and catalysis and highlights green chemistry principles was developed. Students synthesized two "N"-heterocyclic carbene ligands, used them to prepare two well-defined copper(I) complexes and subsequently utilized the complexes as…

Inorganic separator technology program

NASA Technical Reports Server (NTRS)

Smatko, J. S.; Weaver, R. D.; Kalhammer, F. R.

1973-01-01

Testing and failure analyses of silver zinc cells with largely inorganic separators were performed. The results showed that the wet stand and cycle life objective of the silver-zinc cell development program were essentially accomplished and led to recommendations for cell composition, design, and operation that should yield further improvement in wet and cycle life. A series of advanced inorganic materials was successfully developed and formulated into rigid and semiflexible separator samples. Suitable screening tests for evaluation of largely inorganic separators were selected and modified for application to the separator materials. The results showed that many of these formulations are potentially superior to previously used materials and permitted selection of three promising materials for further evaluation in silver-zinc cells.

New trends in chemistry and materials science in extremely tight space

DOE PAGES

Song, Yang; Manaa, M. Riad

2012-01-26

Pressure plays a critical role in regulating the structures and properties of materials. Since Percy Bridgeman was recognized by the 1946 Nobel Prize in Physics for his contribution in high-pressure physics, high-pressure research has remained an interdisciplinary scientific frontier with many extraordinary breakthroughs. Over the past decade or so, in particular, high-pressure chemistry and materials research has undergone major advances with the discovery of numerous exotic structures and properties. Furthermore, brand new classes of inorganic materials of unusual stoichiometries and crystal structures, which have a wide range of optical, mechanical, electronic and magnetic properties, have been produced at high pressures.

New trends in chemistry and materials science in extremely tight space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Yang; Manaa, M. Riad

Pressure plays a critical role in regulating the structures and properties of materials. Since Percy Bridgeman was recognized by the 1946 Nobel Prize in Physics for his contribution in high-pressure physics, high-pressure research has remained an interdisciplinary scientific frontier with many extraordinary breakthroughs. Over the past decade or so, in particular, high-pressure chemistry and materials research has undergone major advances with the discovery of numerous exotic structures and properties. Furthermore, brand new classes of inorganic materials of unusual stoichiometries and crystal structures, which have a wide range of optical, mechanical, electronic and magnetic properties, have been produced at high pressures.

A Laboratory Program for Bioinorganic Chemistry

ERIC Educational Resources Information Center

Ochiai, Ei-ichiro

1973-01-01

Outlines a laboratory course entitled Inorganic Chemistry for Biological Sciences'' which is designed primarily for juniors in biochemistry, physiology, and soil sciences. Inclusion of relevant environmental topics is indicated. (CC)

Acquisition of an Advanced Thermal Analysis andImaging System for Integration with Interdisciplinary Researchand Education in Low Density Organic Inorganic Materials

DTIC Science & Technology

2017-12-02

Report: Acquisition of an Advanced Thermal Analysis and Imaging System for Integration with Interdisciplinary Research and Education in Low Density...for Integration with Interdisciplinary Research and Education in Low Density Organic-Inorganic Materials Report Term: 0-Other Email: dmisra2

What Does a Student Know Who Earns a Top Score on the Advanced Placement Chemistry Exam?

ERIC Educational Resources Information Center

Claesgens, Jennifer; Daubenmire, Paul L.; Scalise, Kathleen M.; Balicki, Scott; Gochyyev, Perman; Stacy, Angelica M.

2014-01-01

This paper compares the performance of students at a high-performing U.S. public school (n = 64) on the advanced placement (AP) chemistry exam to their performance on the ChemQuery assessment system. The AP chemistry exam was chosen because, as the National Research Council acknowledges, it is the "perceived standard of excellence and school…

Progress and perspective of inorganic nanoparticles based siRNA delivery system

PubMed Central

Jiang, Ying; Huo, Shuaidong; Hardie, Joseph; Liang, Xing-Jie; Rotello, Vincent M.

2016-01-01

Introduction Small interfering RNA (siRNA) is an effective method for regulating the expression of proteins, even “undruggable” ones that are nearly impossible to target through traditional small molecule therapeutics. Delivery to the cell and then to the cytosol is the primary requirement for realization of therapeutic potential of siRNA. Areas covered We summarize recent advances in the design of inorganic nanoparticle with surface functionality and physicochemical properties engineered for siRNA delivery. Specifically, we discuss the main approaches developed so far to load siRNA into/onto NPs, and NP surface chemistry engineered for enhanced intracellular siRNA delivery, endosomal escape, and targeted delivery of siRNA to disease cells and tissues. Expert Opinion Several challenges remain in developing inorganic NPs for efficient and effective siRNA delivery. Getting the material to the chosen site is important, however the greatest hurdle may well be delivery into the cytosol, either through efficient endosomal escape or by direct cytosolic siRNA delivery. Effective delivery at the organismic and cellular level coupled with biocompatible vehicles with low immunogenic response will facilitate the clinical translation of RNAi for the treatment of genetic diseases. PMID:26735861

A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

NASA Technical Reports Server (NTRS)

Reid, Concha; Bennett, William

2009-01-01

NASA's Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair lunar lander and the Extravehicular Activities (EVA) advanced lunar surface spacesuit. These customers require safe, reliable energy storage systems with extremely high specific energy as compared to today's state-of-the-art batteries. Based on customer requirements, the specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery level at 0 degrees Celsius (degrees Celcius) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation over 0 to 30 degrees C, and 200 cycles are targeted. The team, consisting of members from NASA Glenn Research Center, Johnson Space Center, and Jet Propulsion laboratory, surveyed the literature, compiled information on recent materials developments, and consulted with other battery experts in the community to identify advanced battery materials that might be capable of achieving the desired results with further development. A variety of electrode materials were considered, including layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. lithium-sulfur systems were also considered. Hypothetical cell constructs that combined compatible anode and cathode materials with suitable electrolytes, separators, current collectors, headers, and cell enclosures were modeled. While some of these advanced materials are projected to obtain the desired electrical performance, there are risks that also factored into the decision making process. The risks include uncertainties due to issues such as safety of a system containing some of these materials, ease of scaling-up of large batches of raw materials, adaptability of the materials to processing using established

USSR Report, Chemistry

DTIC Science & Technology

1984-01-06

Sep-Oct 83) ................................. ANALYTICAL CHEMISTRY Ionometric Determination of Copper in Organic Compounds S(S. L. Davydova, et al...Committee Reviews Progress in Fertilizer Industry (EKONOMICHESKAYA GAZETA, No 42, Oct 83) .................. 30 INORGANIC COMPOUNDS Speed of Ultrasound...Sep 83).. ........... .......... . . .. . . . . .... 39 NITROGEN COMPOUNDS Phototropy of Quaternary Ammonium Salts of N,N’-Bis- Substituted Diimides

Organic Experiments for Introductory Chemistry.

ERIC Educational Resources Information Center

Rayner-Canham, Geoff

1985-01-01

Describes test-tube organic chemistry procedures (using comparatively safe reagents) for the beginning student. These procedures are used to: examine differences between saturated and unsaturated hydrocarbons; compare structural isomers; and compare organic and inorganic acids and bases. (DH)

Communist China’s Progress in Inorganic, Organic, and Physical Chemistry in Recent Decade

DTIC Science & Technology

1960-03-16

situation, develp t ms bin- dered. ?ollwving the revival of nastieal tahvoloe In World War I, Inorganic chemstry , lMke other branches of che•strj, mde seem...in high-density sam~ples." Looking back at the devolou t of our inorganic chemstry in the pest decadse, we believe that today’s echievemt from a blank...8217, and rich chemical resources are Iamting for. solutions, Therefore, Our Inorganic chemstry workers must bear in mind the development of Chinats

Recent Advances of Metallocenes for Medicinal Chemistry.

PubMed

Santos, Miguel M; Bastos, Pedro; Catela, Isabelle; Zalewska, Karolina; Branco, Luis C

2017-01-01

The recent advances for the synthesis and application of different metallocenes for Medicinal Chemistry is reviewed. This manuscript presents the different metallocene scaffolds, with special emphasis on ferrocene derivatives, and their potential pharmaceutical application. Over the last years, the synthesis of new metallocene compounds and their biological and medicinal effects against some types of diseases (e.g. anti-tumoral, antibiotics, anti-viral) have been reported. From the medicinal point of view, the attractive properties of metallocene derivatives, such as their high stability, low toxicity and appealing redox behaviors are particularly relevant. This area has attracted many researchers as well as the pharmaceutical industry due to the promising results of some metallocenes, in particular ferrocene compounds, in breast cancer and malaria. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Chemical Energetics. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S3.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on chemical energetics is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, provides a clear yet detailed and thorough introduction to the topic. Level one extends ideas from previous courses, introduces and emphasizes the importance of Hess'…

Atomic Structure. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S2.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on atomic structure is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit consists of two levels. Level one focuses on the atomic nucleus. Level two focuses on the arrangement of extranuclear electrons, approaching atomic orbitals through both electron bombardment and spectra.…

Hybrid organic-inorganic rotaxanes and molecular shuttles.

PubMed

Lee, Chin-Fa; Leigh, David A; Pritchard, Robin G; Schultz, David; Teat, Simon J; Timco, Grigore A; Winpenny, Richard E P

2009-03-19

The tetravalency of carbon and its ability to form covalent bonds with itself and other elements enables large organic molecules with complex structures, functions and dynamics to be constructed. The varied electronic configurations and bonding patterns of inorganic elements, on the other hand, can impart diverse electronic, magnetic, catalytic and other useful properties to molecular-level structures. Some hybrid organic-inorganic materials that combine features of both chemistries have been developed, most notably metal-organic frameworks, dense and extended organic-inorganic frameworks and coordination polymers. Metal ions have also been incorporated into molecules that contain interlocked subunits, such as rotaxanes and catenanes, and structures in which many inorganic clusters encircle polymer chains have been described. Here we report the synthesis of a series of discrete rotaxane molecules in which inorganic and organic structural units are linked together mechanically at the molecular level. Structural units (dialkyammonium groups) in dumb-bell-shaped organic molecules template the assembly of essentially inorganic 'rings' about 'axles' to form rotaxanes consisting of various numbers of rings and axles. One of the rotaxanes behaves as a 'molecular shuttle': the ring moves between two binding sites on the axle in a large-amplitude motion typical of some synthetic molecular machine systems. The architecture of the rotaxanes ensures that the electronic, magnetic and paramagnetic characteristics of the inorganic rings-properties that could make them suitable as qubits for quantum computers-can influence, and potentially be influenced by, the organic portion of the molecule.

First-Year Chemistry in the Context of the Periodic Table.

ERIC Educational Resources Information Center

Woodgate, Sheila D.

1995-01-01

Describes the methods that have been developed to blend descriptive chemistry and principles in a first-year chemistry course. The key is active teaching of the subject using the periodic table as a template. Inorganic chemistry is taught using a group approach: developing trends that help teaching and learning become obvious if all elements of…

ADVANCES IN GREEN CHEMISTRY: CHEMICAL SYNTHESES USING MICROWAVE IRRADIATION, ISBN 81-901238-5-8

EPA Science Inventory

16. Abstract Advances in Green Chemistry: Chemical Syntheses Using Microwave Irradiation
Microwave-accelerated chemical syntheses in solvents as well as under solvent-free conditions have witnessed an explosive growth. The technique has found widespread application predomi...

Influence of surface chemistry of carbon materials on their interactions with inorganic nitrogen contaminants in soil and water.

PubMed

Sumaraj; Padhye, Lokesh P

2017-10-01

Inorganic nitrogen contaminants (INC) (NH 4 + , NO 3 - , NO 2 - , NH 3 , NO, NO 2 , and N 2 O) pose a growing risk to the environment, and their remediation methods are highly sought after. Application of carbon materials (CM), such as biochar and activated carbon, to remediate INC from agricultural fields and wastewater treatment plants has gained a significant interest since past few years. Understanding the role of surface chemistry of CM in adsorption of various INC is highly critical to increase adsorption efficiency as well as to assess the long term impact of using these highly recalcitrant CM for remediation of INC. Critical reviews of adsorption studies related to INC have revealed that carbon surface chemistry (surface functional groups, pH, Eh, elemental composition, and mineral content) has significant influence on adsorption of INC. Compared to basic functional groups, oxygen containing surface functional groups have been found to be more influential for adsorption of INC. However, basic sites on carbon materials still play an important role in chemisorption of anionic INC. Apart from surface functional groups, pH, Eh and pH zpc of CM and elemental and mineral composition of its surface are important properties capable of altering INC interactions with CM. This review summarizes our current understanding of INC interactions with CM's surface through the known chemisorption mechanisms: electrostatic interaction, hydrogen bonding, electron donor-acceptor mechanism, hydrophobic and hydrophilic interaction, chemisorption aided by minerals, and interactions influenced by pH and elemental composition. Change in surface chemistry of CM in soil during aging is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Halogens. Independent Learning Project for Advanced Chemistry (ILPAC). Unit I2.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, focuses on the elements and compounds of Group IV (halogens) of the periodic table. Level one deals with the physical and chemical properties of the individual elements. Level two considers…

Advanced electron microscopy characterization of nanomaterials for catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Dong

Transmission electron microscopy (TEM) has become one of the most powerful techniques in the fields of material science, inorganic chemistry and nanotechnology. In terms of resolutions, advanced TEM may reach a high spatial resolution of 0.05 nm, a high energy-resolution of 7 meV. In addition, in situ TEM can help researcher to image the process happened within 1 ms. This paper reviews the recent technical approaches of applying advanced TEM characterization on nanomaterials for catalysis. The text is organized according to the demanded information of nanocrystals from the perspective of application: for example, size, composition, phase, strain, and morphology. Themore » electron beam induced effect and in situ TEM are also introduced. As a result, I hope this review can help the scientists in related fields to take advantage of advanced TEM to their own researches.« less

Advanced electron microscopy characterization of nanomaterials for catalysis

DOE PAGES

Su, Dong

2017-04-01

Transmission electron microscopy (TEM) has become one of the most powerful techniques in the fields of material science, inorganic chemistry and nanotechnology. In terms of resolutions, advanced TEM may reach a high spatial resolution of 0.05 nm, a high energy-resolution of 7 meV. In addition, in situ TEM can help researcher to image the process happened within 1 ms. This paper reviews the recent technical approaches of applying advanced TEM characterization on nanomaterials for catalysis. The text is organized according to the demanded information of nanocrystals from the perspective of application: for example, size, composition, phase, strain, and morphology. Themore » electron beam induced effect and in situ TEM are also introduced. As a result, I hope this review can help the scientists in related fields to take advantage of advanced TEM to their own researches.« less

Interannual stability of organic to inorganic carbon production on a coral atoll

NASA Astrophysics Data System (ADS)

Kwiatkowski, Lester; Albright, Rebecca; Hosfelt, Jessica; Nebuchina, Yana; Ninokawa, Aaron; Rivlin, Tanya; Sesboüé, Marine; Wolfe, Kennedy; Caldeira, Ken

2016-04-01

Ocean acidification has the potential to adversely affect marine calcifying organisms, with substantial ocean ecosystem impacts projected over the 21st century. Characterizing the in situ sensitivity of calcifying ecosystems to natural variability in carbonate chemistry may improve our understanding of the long-term impacts of ocean acidification. We explore the potential for intensive temporal sampling to isolate the influence of carbonate chemistry on community calcification rates of a coral reef and compare the ratio of organic to inorganic carbon production to previous studies at the same location. Even with intensive temporal sampling, community calcification displays only a weak dependence on carbonate chemistry variability. However, across three years of sampling, the ratio of organic to inorganic carbon production is highly consistent. Although further work is required to quantify the spatial variability associated with such ratios, this suggests that these measurements have the potential to indicate the response of coral reefs to ongoing disturbance, ocean acidification, and climate change.

Recent advances in porous nanoparticles for drug delivery in antitumoral applications: inorganic nanoparticles and nanoscale metal-organic frameworks.

PubMed

Baeza, Alejandro; Ruiz-Molina, Daniel; Vallet-Regí, María

2017-06-01

Nanotechnology has provided new tools for addressing unmet clinical situations, especially in the oncology field. The development of smart nanocarriers able to deliver chemotherapeutic agents specifically to the diseased cells and to release them in a controlled way has offered a paramount advantage over conventional therapy. Areas covered: Among the different types of nanoparticle that can be employed for this purpose, inorganic porous materials have received significant attention in the last decade due to their unique properties such as high loading capacity, chemical and physical robustness, low toxicity and easy and cheap production in the laboratory. This review discuss the recent advances performed in the application of porous inorganic and metal-organic materials for antitumoral therapy, paying special attention to the application of mesoporous silica, porous silicon and metal-organic nanoparticles. Expert opinion: The use of porous inorganic nanoparticles as drug carriers for cancer therapy has the potential to improve the life expectancy of the patients affected by this disease. However, much work is needed to overcome their drawbacks, which are aggravated by their hard nature, exploiting the advantages offered by highly the ordered pore network of these materials.

Recent Advances in Archaeological Chemistry: A Summary of the Three Major Papers Presented as an Introduction to the Archeological Chemistry Symposium, Anaheim, California

NASA Astrophysics Data System (ADS)

Chen, Wen; Orna, Mary Virginia; O. S., U.

1996-06-01

Modern archaeology is fully supported by advances in science and technology. With the development of chemical and biochemical analyses, the task of the archaeological chemist has become more complex than ever over the past decade. In the symposium on archaeological chemistry held at the American Chemical Society National Meeting in Anaheim, California, from April 2-6, 1995, three noted scientists who have made seminal contributions in their respective fields presented an accompanying pedagogical symposium to provide introductory information on how modern chemistry and biochemistry have revolutionized modern archaeological studies at a molecular level. These three scientists and their presentations were: Stanley Ambrose, "Advances in Stable Isotope Analysis in Dietary Reconstruction"; Svante Pääbo, "Ancient DNA as a Means to Study the History of Humans and Extinct Creatures"; and Robert Hedges, "Radiocarbon Dating of Archaeological Bone by Accelerator Mass Spectrometry.

Mesoporous inorganic nanoscale particles for drug adsorption and controlled release.

PubMed

Cavallaro, Giuseppe; Lazzara, Giuseppe; Fakhrullin, Rawil

2018-03-01

The review provides an overview of the mesoporous inorganic particles employed as drug delivery systems for controlled and sustained release of drugs. We have classified promising nanomaterials for drug delivery on the basis of their natural or synthetic origin. Nanoclays are available in different morphologies (nanotubes, nanoplates and nanofibers) and they are typically available at low cost from natural resources. The surface chemistry of nanoclays is versatile for targeted modifications to control loading and release properties. Synthetic nanomaterials (imogolite, laponite and mesoporous silica) present the advantages of well-established purity and availability with size features that are finely controlled. Both nanoclays and inorganic synthetic nanoparticles can be functionalized forming organic/inorganic architectures with stimuli-responsive features.

Molecular Modeling and Computational Chemistry at Humboldt State University.

ERIC Educational Resources Information Center

Paselk, Richard A.; Zoellner, Robert W.

2002-01-01

Describes a molecular modeling and computational chemistry (MM&CC) facility for undergraduate instruction and research at Humboldt State University. This facility complex allows the introduction of MM&CC throughout the chemistry curriculum with tailored experiments in general, organic, and inorganic courses as well as a new molecular modeling…

The Mole. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S1.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on the mole is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, designed to help students consolidate some of the ideas about the mole learned in previous courses, consists of two levels. The first level focuses on: (1) relative mass; (2) the concept of the mole as the unit…

Contrasting the material chemistry of Cu 2ZnSnSe 4 and Cu 2ZnSnS (4-x)Se x

DOE PAGES

Aguiar, Jeffery A.; Patel, Maulik; Aoki, Toshihiro; ...

2016-02-02

Earth-abundant sustainable inorganic thin-film solar cells, independent of precious elements, pivot on a marginal material phase space targeting specific compounds. Advanced materials characterization efforts are necessary to expose the roles of microstructure, chemistry, and interfaces. Here, the earth-abundant solar cell device, Cu 2ZnSnS (4-x)Se x, is reported, which shows a high abundance of secondary phases compared to similarly grown Cu 2ZnSnSe 4.

Advances in the synthesis of inorganic nanotubes and fullerene-like nanoparticles.

PubMed

Tenne, Reshef

2003-11-03

In analogy to graphite, nanoparticles of inorganic compounds with lamellar two-dimensional structure, such as MoS(2), are not stable against folding, and can adopt nanotubular and fullerene-like structures, nicknamed inorganic fullerenes or IF. Various applications for such nanomaterials were proposed. For instance, IF-WS(2) nanoparticles were shown to have beneficial effects as solid lubricants and as part of tribological surfaces. Further applications of IF for high-tensile-strength fibers, hydrogen storage, rechargeable batteries, catalysis, and in nanotechnology are being contemplated. This Minireview highlights some of the latest developments in the synthesis of inorganic nanotubes and fullerene-like structures. Some structural aspects and properties of IF, which are distinct from the bulk materials, are briefly discussed.

Inorganic materials for bone repair or replacement applications.

PubMed

Hertz, Audrey; Bruce, Ian J

2007-12-01

In recent years, excipient systems have been used increasingly in biomedicine in reconstructive and replacement surgery, as bone cements, drug-delivery vehicles and contrast agents. Particularly, interest has been growing in the development and application of controlled pore inorganic ceramic materials for use in bone-replacement and bone-repair roles and, in this context, attention has been focused on calcium-phosphate, bioactive glasses and SiO2- and TiO2-based materials. It has been shown that inorganic materials that most closely mimic bone structure and surface chemistry most closely function best in bone replacement/repair and, in particular, if a substance possesses a macroporous structure (pores and interconnections >100 microm diameter), then cell infiltration, bone growth and vascularization can all be promoted. The surface roughness and micro/mesoporosity of a material have also been observed to significantly influence its ability to promote apatite nucleation and cell attachment significantly. Pores (where present) can also be packed with pharmaceuticals and biomolecules (e.g., bone morphogenetic proteins [BMPs], which can stimulate bone formation). Finally, the most bio-efficient - in terms of collagen formation and apatite nucleation - materials are those that are able to provide soluble mineralizing species (Si, Ca, PO(4)) at their implant sites and/or are doped or have been surface-activated with specific functional groups. This article presents the context and latest advances in the field of bone-repair materials, especially with respect to the development of bioactive glasses and micro/mesoporous and macroporous inorganic scaffolds. It deals with the possible methods of preparing porous pure/doped or functionalized silicas or their composites, the studies that have been undertaken to evaluate their abilities to act as bone repair scaffolds and also presents future directions for work in that context.

Industrial Chemistry: A Series of New Courses at the Undergraduate Level.

ERIC Educational Resources Information Center

Jasinski, Jerry P.; Miller, Robert E.

1985-01-01

Describes four courses in the undergraduate bachelor of science program in industrial chemistry at Keene State College (NH). They are (1) introduction to industrial chemistry; (2) polymers--synthesis and separation techniques; (3) inorganic industrial processes; and (4) organic industrial processes. (JN)

Silicon and germanium nanoparticles with tailored surface chemistry as novel inorganic fiber brightening agents.

PubMed

Deb-Choudhury, Santanu; Prabakar, Sujay; Krsinic, Gail; Dyer, Jolon M; Tilley, Richard D

2013-07-31

Low-molecular-weight organic molecules, such as coumarins and stilbenes, are used commercially as fluorescent whitening agents (FWAs) to mask photoyellowing and to brighten colors in fabrics. FWAs achieve this by radiating extra blue light, thus changing the hue and also adding to the brightness. However, organic FWAs can rapidly photodegrade in the presence of ultraviolet (UV) radiation, exacerbating the yellowing process through a reaction involving singlet oxygen species. Inorganic nanoparticles, on the other hand, can provide a similar brightening effect with the added advantage of photostability. We report a targeted approach in designing new inorganic silicon- and germanium-based nanoparticles, functionalized with hydrophilic (amine) surface terminations as novel inorganic FWAs. When applied on wool, by incorporation in a sol-gel Si matrix, the inorganic FWAs improved brightness properties, demonstrated enhanced photostability toward UV radiation, especially the germanium nanoparticles, and also generated considerably lower levels of reactive oxygen species compared to a commercial stilbene-based organic FWA, Uvitex NFW.

Recent advances in the application of electron tomography to materials chemistry.

PubMed

Leary, Rowan; Midgley, Paul A; Thomas, John Meurig

2012-10-16

, have all contributed significantly to the further development of quantitative 3D studies of nanostructured materials, including nanoparticle-heterogeneous catalysts, fuel-cell components, and drug-delivery systems, as well as photovoltaic and plasmonic devices, and are likely to enhance our knowledge of many other facets of materials chemistry, such as organic-inorganic composites, solar-energy devices, bionanotechnology, biomineralization, and energy-storage systems composed of high-permittivity metal oxides.

Moving Beyond the Single Center--Ways to Reinforce Molecular Orbital Theory in an Inorganic Course

ERIC Educational Resources Information Center

Cass, Marion E.; Hollingsworth, William E.

2004-01-01

It is suggested that molecular theory should be taught earlier in the inorganic chemistry curriculum even in the introductory chemistry course in order to integrate molecular orbital arguments more effectively throughout the curriculum. The method of teaching relies on having access to molecular modeling software as having access to such software…

Survey of application of radiation to preparative chemistry

NASA Technical Reports Server (NTRS)

Philipp, W. H.

1973-01-01

The use of radiation for preparative chemistry in liquid solutions is investigated. General principles are presented and preparations involving reduction, oxidation, polymerization, and decomposition are given. The use of various solvents, water, other inorganic liquids and organic liquids for this purpose is discussed. Finally, a commentary is made on some specific applications where radiation chemistry as a preparative technique may be useful.

Historical Analysis of the Inorganic Chemistry Curriculum Using ACS Examinations as Artifacts

ERIC Educational Resources Information Center

Srinivasan, Shalini; Reisner, Barbara A.; Smith, Sheila R.; Stewart, Joanne L.; Johnson, Adam R.; Lin, Shirley; Marek, Keith A.; Nataro, Chip; Murphy, Kristen L.; Raker, Jeffrey R.

2018-01-01

ACS Examinations provide a lens through which to examine historical changes in topic coverage via analyses of course-specific examinations. This study is an extension of work completed previously by the ACS Exams Research Staff and collaborators in general chemistry, organic chemistry, and physical chemistry to explore content changes in the…

Equilibrium I: Principles. Independent Learning Project for Advanced Chemistry (ILPAC). Unit P2.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on the principles of equilibrium is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit consists of two levels. After a treatment of non-mathematical aspects in level one (the idea of a reversible reaction, characteristics of an equilibrium state, the Le Chatelier's principle),…

Bonding and Structure. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S4.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on chemical bonding is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, provides an introduction to the main types of chemical bonding and important aspects of structure. The main emphasis is placed on such topics as ionic and covalent bonding,…

s-Block Elements. Independent Learning Project for Advanced Chemistry (ILPAC). Unit I1.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two sections and an appendix, focuses on the elements and compounds of Groups I and II (the s-block) of the periodic table. The groups are treated concurrently to note comparisons between groups and to…

The Gaseous State. Independent Learning Project for Advanced Chemistry (ILPAC). Unit P1.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on the gaseous state is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit consists of two levels. Level one deals with the distinctive characteristics of gases, then considers the gas laws, in particular the ideal gas equation and its applications. Level two concentrates on…

A One-Pot Synthesis of m-Terphenyls: A Guided Exploration of Reaction Chemistry, Chromatography, and Spectroscopy. A Miniproject for the Advanced Organic Chemistry Laboratory

NASA Astrophysics Data System (ADS)

Anam, Kishorekumar T.; Curtis, Michael P.; Irfan, Muhammad J.; Johnson, Michael P.; Royer, Andrew P.; Shahmohammadi, Kianor; Vinod, Thottumkara K.

2002-05-01

This four-week project-based laboratory exercise, developed for advanced organic chemistry students, involves a one-pot synthesis of m-terphenyls. Chemistry of aryl diazonium salts and Grignard reagents and reactivity of aryne intermediates toward nucleophilic reagents form the reaction chemistry basis for the project. The project exposes students to a number of important laboratory techniques (thin-layer chromatography, gas chromatography-mass spectrometry, and column chromatography) for monitoring reaction progress and product isolation. A variety of spectroscopic techniques, including IR, 1H NMR, 13C NMR, and attached proton test are used for product characterization. Students are also introduced to a useful empirical relationship to help predict (with considerable accuracy) the 13C chemical shift values of carbon atoms of substituted benzenes.

A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds.

PubMed

de Jong, Maarten; Chen, Wei; Notestine, Randy; Persson, Kristin; Ceder, Gerbrand; Jain, Anubhav; Asta, Mark; Gamst, Anthony

2016-10-03

Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. The approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials.

A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds

PubMed Central

de Jong, Maarten; Chen, Wei; Notestine, Randy; Persson, Kristin; Ceder, Gerbrand; Jain, Anubhav; Asta, Mark; Gamst, Anthony

2016-01-01

Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. The approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials. PMID:27694824

A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds

DOE PAGES

de Jong, Maarten; Chen, Wei; Notestine, Randy; ...

2016-10-03

Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. Themore » approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials.« less

Exploring Zimbabwean Advanced Level Chemistry Students' Approaches to Investigations from a Learning Perspective

ERIC Educational Resources Information Center

Chirikure, Tamirirofa; Hobden, Paul; Hobden, Sally

2018-01-01

In this paper we report on the findings of a study on Advanced Level Chemistry students' approaches to investigations from a learning perspective in the Zimbabwean educational context. Students' approaches to investigations are inextricably linked to the quality of learning and performances in these practical activities. An explanatory…

Organic materials as templates for the formation of mesoporous inorganic materials and ordered inorganic nanocomposites

NASA Astrophysics Data System (ADS)

Ziegler, Christopher R.

Hierarchically structured inorganic materials are everywhere in nature. From unicellular aquatic algae such as diatoms to the bones and/or cartilage that comprise the skeletal systems of vertebrates. Complex mechanisms involving site-specific chemistries and precision kinetics are responsible for the formation of such structures. In the synthetic realm, reproduction of even the most basic hierarchical structure effortlessly produced in nature is difficult. However, through the utilization of self-assembling structures or "templates", such as polymers or amphiphilic surfactants, combined with some favorable interaction between a chosen inorganic, the potential exists to imprint an inorganic material with a morphology dictated via synthetic molecular self-assembly. In doing so, a very basic hierarchical structure is formed on the angstrom and nanometer scales. The work presented herein utilizes the self-assembly of either surfactants or block copolymers with the desired inorganic or inorganic precursor to form templated inorganic structures. Specifically, mesoporous silica spheres and copolymer directed calcium phosphate-polymer composites were formed through the co-assembly of an organic template and a precursor to form the desired mesostructured inorganic. For the case of the mesoporous silica spheres, a silica precursor was mixed with cetyltrimethylammonium bromide and cysteamine, a highly effective biomimetic catalyst for the conversion of alkoxysilanes to silica. Through charge-based interactions between anionic silica species and the micelle-forming cationic surfactant, ordered silica structures resulted. The incorporation of a novel, effective catalyst was found to form highly condensed silica spheres for potential application as catalyst supports or an encapsulation media. Ordered calcium phosphate-polymer composites were formed using two routes. Both routes take advantage of hydrogen bonding and ionic interactions between the calcium and phosphate precursors

SCIENCE VERSION OF PM CHEMISTRY MODEL

EPA Science Inventory

PM chemistry models containing detailed treatments of key chemical processes controlling ambient concentrations of inorganic and organic compounds in PM2.5 are needed to develop strategies for reducing PM2.5 concentrations. This task, that builds on previous research conducted i...

High School Students' Attitudes and Beliefs on Using the Science Writing Heuristic in an Advanced Placement Chemistry Class

ERIC Educational Resources Information Center

Putti, Alice

2011-01-01

This paper discusses student attitudes and beliefs on using the Science Writing Heuristic (SWH) in an advanced placement (AP) chemistry classroom. During the 2007 school year, the SWH was used in a class of 24 AP chemistry students. Using a Likert-type survey, student attitudes and beliefs on the process were determined. Methods for the study are…

Recent Advances in the Chemistry and Biology of Naturally Occurring Antibiotics

PubMed Central

Chen, Jason S.; Edmonds, David J.; Estrada, Anthony A.

2009-01-01

Lead-in Ever since the world-shaping discovery of penicillin, nature’s molecular diversity has been extensively screened for new medications and lead compounds in drug discovery. The search for anti-infective agents intended to combat infectious diseases has been of particular interest and has enjoyed a high degree of success. Indeed, the history of antibiotics is marked with impressive discoveries and drug development stories, the overwhelming majority of which have their origins in nature. Chemistry, and in particular chemical synthesis, has played a major role in bringing naturally occurring antibiotics and their derivatives to the clinic, and no doubt these disciplines will continue to be key enabling technologies for future developments in the field. In this review article, we highlight a number of recent discoveries and advances in the chemistry, biology, and medicine of naturally occurring antibiotics, with particular emphasis on the total synthesis, analog design, and biological evaluation of molecules with novel mechanisms of action. PMID:19130444

Chitosan bio-based organic-inorganic hybrid aerogel microspheres.

PubMed

El Kadib, Abdelkrim; Bousmina, Mosto

2012-07-02

Recently, organic-inorganic hybrid materials have attracted tremendous attention thanks to their outstanding properties, their efficiency, versatility and their promising applications in a broad range of areas at the interface of chemistry and biology. This article deals with a new family of surface-reactive organic-inorganic hybrid materials built from chitosan microspheres. The gelation of chitosan (a renewable amino carbohydrate obtained by deacetylation of chitin) by pH inversion affords highly dispersed fibrillar networks shaped as self-standing microspheres. Nanocasting of sol-gel processable monomeric alkoxides inside these natural hydrocolloids and their subsequent CO(2) supercritical drying provide high-surface-area organic-inorganic hybrid materials. Examples including chitosan-SiO(2), chitosan-TiO(2), chitosan-redox-clusters and chitosan-clay-aerogel microspheres are described and discussed on the basis of their textural and structural properties, thermal and chemical stability and their performance in catalysis and adsorption. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ENVIRONMENTAL CHEMISTRY

EPA Science Inventory

Environmental chemistry is applied to estimating the exposure of ecosystems and humans to various chemical environmental stressors. Among the stressors of concern are mercury, pesticides, and arsenic. Advanced analytical chemistry techniques are used to measure these stressors ...

Architecture and Surface Chemistry of Compound Nanoclusters

DTIC Science & Technology

2012-08-01

spectroscopy of metal carbonyls and carbocations: Inorganic and organic chemistry in the gas phase," Molecular Dynamics Seminar, Fritz Haber Institute...Disclosures none Pi Honors/Awards Alexander von Humboldt Fellowship ( Fritz Haber Institute, Berlin), 2007-present American Chemical Society

Inorganic Nanomaterials as Carriers for Drug Delivery.

PubMed

Chen, Shizhu; Hao, Xiaohong; Liang, Xingjie; Zhang, Qun; Zhang, Cuimiao; Zhou, Guoqiang; Shen, Shigang; Jia, Guang; Zhang, Jinchao

2016-01-01

For safe and effective therapy, drugs must be delivered efficiently and with minimal systemic side effects. Nanostructured drug carriers enable the delivery of small-molecule drugs as well as nucleic acids and proteins. Inorganic nanomaterials are ideal for drug delivery platforms due to their unique physicochemical properties, such as facile preparation, good storage stability and biocompatibility. Many inorganic nanostructure-based drug delivery platforms have been prepared. Although there are still many obstacles to overcome, significant advances have been made in recent years. This review focuses on the status and development of inorganic nanostructures, including silica, quantum dots, gold, carbon-based and magnetic iron oxide-based nanostructures, as carriers for chemical and biological drugs. We specifically highlight the extensive use of these inorganic drug carriers for cancer therapy. Finally, we discuss the most important areas in the field that urgently require further study.

Architecture and Surface Chemistry of Compound Nanoclusters

DTIC Science & Technology

2012-07-31

Inorganic and organic chemistry in the gas phase," Molecular Dynamics Seminar, Fritz Haber Institute, Berlin, Germany, June 2010. 12. "Infrared...Patent Disclosures none Pi Honors/Awards Alexander von Humboldt Fellowship ( Fritz Haber Institute, Berlin), 2007-present American Chemical

Calcifying tissue regeneration via biomimetic materials chemistry

PubMed Central

Green, David W.; Goto, Tazuko K.; Kim, Kye-Seong; Jung, Han-Sung

2014-01-01

Materials chemistry is making a fundamental impact in regenerative sciences providing many platforms for tissue development. However, there is a surprising paucity of replacements that accurately mimic the structure and function of the structural fabric of tissues or promote faithful tissue reconstruction. Methodologies in biomimetic materials chemistry have shown promise in replicating morphologies, architectures and functional building blocks of acellular mineralized tissues dentine, enamel and bone or that can be used to fully regenerate them with integrated cell populations. Biomimetic materials chemistry encompasses the two processes of crystal formation and mineralization of crystals into inorganic formations on organic templates. This review will revisit the successes of biomimetics materials chemistry in regenerative medicine, including coccolithophore simulants able to promote in vivo bone formation. In-depth knowledge of biomineralization throughout evolution informs the biomimetic materials chemist of the most effective techniques for regenerative framework construction exemplified via exploitation of liquid crystals (LCs) and complex self-organizing media. Therefore, a new innovative direction would be to create chemical environments that perform reaction–diffusion exchanges as the basis for building complex biomimetic inorganic structures. This has evolved widely in biology, as have LCs, serving as self-organizing templates in pattern formation of structural biomaterials. For instance, a study is highlighted in which artificially fabricated chiral LCs, made from bacteriophages are transformed into a faithful copy of enamel. While chemical-based strategies are highly promising at creating new biomimetic structures there are limits to the degree of complexity that can be generated. Thus, there may be good reason to implement living or artificial cells in ‘morphosynthesis’ of complex inorganic constructs. In the future, cellular construction is

Silicateins--a novel paradigm in bioinorganic chemistry: enzymatic synthesis of inorganic polymeric silica.

PubMed

Müller, Werner E G; Schröder, Heinz C; Burghard, Zaklina; Pisignano, Dario; Wang, Xiaohong

2013-05-03

The inorganic matrix of the siliceous skeletal elements of sponges, that is, spicules, is formed of amorphous biosilica. Until a decade ago, it remained unclear how the hard biosilica monoliths of the spicules are formed in sponges that live in a silica-poor (<50 μM) aquatic environment. The following two discoveries caused a paradigm shift and allowed an elucidation of the processes underlying spicule formation; first the discovery that in the spicules only one major protein, silicatein, exists and second, that this protein displays a bio-catalytical, enzymatic function. These findings caused a paradigm shift, since silicatein is the first enzyme that catalyzes the formation of an inorganic polymer from an inorganic monomeric substrate. In the present review the successive steps, following the synthesis of the silicatein product, biosilica, and resulting in the formation of the hard monolithic spicules is given. The new insight is assumed to open new horizons in the field of biotechnology and also in biomedicine. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthetic Strategies in the Preparation of Polymer/Inorganic Hybrid Nanoparticles

PubMed Central

Hood, Matthew A.; Mari, Margherita; Muñoz-Espí, Rafael

2014-01-01

This article reviews the recent advances and challenges in the preparation of polymer/inorganic hybrid nanoparticles. We mainly focus on synthetic strategies, basing our classification on whether the inorganic and the polymer components have been formed in situ or ex situ, of the hybrid material. Accordingly, four types of strategies are identified and described, referring to recent examples: (i) ex situ formation of the components and subsequent attachment or integration, either by covalent or noncovalent bonding; (ii) in situ polymerization in the presence of ex situ formed inorganic nanoparticles; (iii) in situ precipitation of the inorganic components on or in polymer structures; and (iv) strategies in which both polymer and inorganic component are simultaneously formed in situ. PMID:28788665

Inorganic nanolayers: structure, preparation, and biomedical applications.

PubMed

Saifullah, Bullo; Hussein, Mohd Zobir B

2015-01-01

Hydrotalcite-like compounds are two-dimensional inorganic nanolayers also known as clay minerals or anionic clays or layered double hydroxides/layered hydroxy salts, and have emerged as a single type of material with numerous biomedical applications, such as drug delivery, gene delivery, cosmetics, and biosensing. Inorganic nanolayers are promising materials due to their fascinating properties, such as ease of preparation, ability to intercalate different type of anions (inorganic, organic, biomolecules, and even genes), high thermal stability, delivery of intercalated anions in a sustained manner, high biocompatibility, and easy biodegradation. Inorganic nanolayers have been the focus for researchers over the last decade, resulting in widening application horizons, especially in the field of biomedical science. These nanolayers have been widely applied in drug and gene delivery. They have also been applied in biosensing technology, and most recently in bioimaging science. The suitability of inorganic nanolayers for application in drug delivery, gene delivery, biosensing technology, and bioimaging science makes them ideal materials to be applied for theranostic purposes. In this paper, we review the structure, methods of preparation, and latest advances made by inorganic nanolayers in such biomedical applications as drug delivery, gene delivery, biosensing, and bioimaging.

Inorganic nanolayers: structure, preparation, and biomedical applications

PubMed Central

Saifullah, Bullo; Hussein, Mohd Zobir B

2015-01-01

Hydrotalcite-like compounds are two-dimensional inorganic nanolayers also known as clay minerals or anionic clays or layered double hydroxides/layered hydroxy salts, and have emerged as a single type of material with numerous biomedical applications, such as drug delivery, gene delivery, cosmetics, and biosensing. Inorganic nanolayers are promising materials due to their fascinating properties, such as ease of preparation, ability to intercalate different type of anions (inorganic, organic, biomolecules, and even genes), high thermal stability, delivery of intercalated anions in a sustained manner, high biocompatibility, and easy biodegradation. Inorganic nanolayers have been the focus for researchers over the last decade, resulting in widening application horizons, especially in the field of biomedical science. These nanolayers have been widely applied in drug and gene delivery. They have also been applied in biosensing technology, and most recently in bioimaging science. The suitability of inorganic nanolayers for application in drug delivery, gene delivery, biosensing technology, and bioimaging science makes them ideal materials to be applied for theranostic purposes. In this paper, we review the structure, methods of preparation, and latest advances made by inorganic nanolayers in such biomedical applications as drug delivery, gene delivery, biosensing, and bioimaging. PMID:26366081

Advancement on Lead-Free Organic-Inorganic Halide Perovskite Solar Cells: A Review.

PubMed

Sani, Faruk; Shafie, Suhaidi; Lim, Hong Ngee; Musa, Abubakar Ohinoyi

2018-06-14

Remarkable attention has been committed to the recently discovered cost effective and solution processable lead-free organic-inorganic halide perovskite solar cells. Recent studies have reported that, within five years, the reported efficiency has reached 9.0%, which makes them an extremely promising and fast developing candidate to compete with conventional lead-based perovskite solar cells. The major challenge associated with the conventional perovskite solar cells is the toxic nature of lead (Pb) used in the active layer of perovskite material. If lead continues to be used in fabricating solar cells, negative health impacts will result in the environment due to the toxicity of lead. Alternatively, lead free perovskite solar cells could give a safe way by substituting low-cost, abundant and non toxic material. This review focuses on formability of lead-free organic-inorganic halide perovskite, alternative metal cations candidates to replace lead (Pb), and possible substitutions of organic cations, as well as halide anions in the lead-free organic-inorganic halide perovskite architecture. Furthermore, the review gives highlights on the impact of organic cations, metal cations and inorganic anions on stability and the overall performance of lead free perovskite solar cells.

Polymeric and Inorganic Fibers

NASA Astrophysics Data System (ADS)

This series presents critical reviews of the present and future trends in polymer and biopolymer science including chemistry, physical chemistry, physics and materials science. It is addressed to all scientists at universities and in industry who wish to keep abreast of advances in the topics covered. Impact Factor Ranking: Always number one in Polymer Science. More information as well as the electronic version of the whole content available at: www.springerlink.

Insights into the physical chemistry of materials from advances in HAADF-STEM

DOE PAGES

Sohlberg, Karl; Pennycook, Timothy J.; Zhou, Wu; ...

2014-11-13

The observation that, ‘‘New tools lead to new science’’[P. S. Weiss, ACS Nano., 2012, 6(3), 1877–1879], is perhaps nowhere more evident than in scanning transmission electron microscopy (STEM). Advances in STEM have endowed this technique with several powerful and complimentary capabilities. For example, the application of high-angle annular dark-field imaging has made possible real-space imaging at subangstrom resolution with Z-contrast (Z = atomic number). Further advances have wrought: simultaneous real-space imaging and elemental identification by using electron energy loss spectroscopy (EELS); 3-dimensional (3D) mapping by depth sectioning; monitoring of surface diffusion by time-sequencing of images; reduced electron energy imaging formore » probing graphenes; etc. In this paper we review how these advances, often coupled with first-principles theory, have led to interesting and important new insights into the physical chemistry of materials. We then review in detail a few specific applications that highlight some of these STEM capabilities.« less

Heavy haze episodes in Beijing during January 2013: Inorganic ion chemistry and source analysis using highly time-resolved measurements from an urban site.

PubMed

Han, Bin; Zhang, Rui; Yang, Wen; Bai, Zhipeng; Ma, Zhiqiang; Zhang, Wenjie

2016-02-15

The heavy air pollution that occurred in Beijing in January of 2013 attracted intense attention around the world. During this period, we conducted highly time-resolved measurements of inorganic ions associated with PM2.5 at an urban site of Beijing, and investigated ion chemistry and potential sources. Hourly concentrations of Cl(-), NO3(-), SO4(2-), Na(+), NH4(+), K(+), Mg(2+), and Ca(2+) were measured. Peak concentrations of SO4(2-) and NO3(-) were observed on the 10th-15th, 21st-24th, and the 26th-30th during this monitoring campaign. The percentages of SO4(2-) and NH4(+) in total ion concentration increased with the enhancement of PM2.5 concentrations, indicating that high concentrations of SO4(2-) and NH4(+) may play important roles in the formation of haze episodes. The ratio of [NO3(-)]/[SO4(2-)] was calculated, revealing that the sources of SO4(2-) would contribute more to the formation of PM2.5 than mobile sources. Diurnal variations of SO4(2-), NO3(-), NH4(+) (SNA) exhibited a similar pattern, with high concentrations at night and low levels during the day, revealing that meteorological conditions, such as mixing layer height, relative humidity, were likely to be responsible for high levels of SNA at night. The roles of meteorological conditions were further discussed in the formation of secondary inorganic ions. Relative humidity and temperature played key roles and exhibited positive correlations with secondary inorganic ions. An aerosol inorganics simulation model showed that SNA existed mainly in the aqueous phase during the sampling period. Furthermore, potential sources were identified by applying positive matrix factorization model. Secondary nitrate, secondary sulfate, coal combustion and biomass burning, as well as fugitive dust, were considered to be major contributors to total ions. Copyright © 2015. Published by Elsevier B.V.

Curriculum Outline for Introduction to Engineering Chemistry. First Edition. Review Cycle-Annual.

ERIC Educational Resources Information Center

Schlenker, Richard M.

This curriculum outline consists of behavioral objectives (called terminal and enabling objectives) for Introduction to Engineering Chemistry, a one-semester, post-secondary course consisting of four 1-hour lectures each week. Course goal is to introduce marine engineering students to the rudiments of basic/introductory inorganic chemistry. The…

Polymer-Attached Functional Inorganic-Organic Hybrid Nano-Composite Aerogels

DTIC Science & Technology

2003-01-01

drugs. The chemistry to synthesize polyamino- siloxane based aerogel composite was discussed. In addition, two approaches to synthesize PHEMA aerogel... Composite Aerogels DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report: TITLE: Materials...Proc. Vol. 740 © 2003 Materials Research Society 112.24 Polymer-Attached Functional Inorganic-Organic Hybrid Nano- composite Aerogels Xipeng Liu, Mingzhe

Filling a Plastic Bag with Carbon Dioxide: A Student-Designed Guided-Inquiry Lab for Advanced Placement and College Chemistry Courses

ERIC Educational Resources Information Center

Lanni, Laura M.

2014-01-01

A guided-inquiry lab, suitable for first-year general chemistry or high school advanced placement chemistry, is presented that uses only inexpensive, store-bought materials. The reaction of sodium bicarbonate (baking soda) with aqueous acetic acid (vinegar), under the constraint of the challenge to completely fill a sealable plastic bag with the…

A Comprehensive Microfluidics Device Construction and Characterization Module for the Advanced Undergraduate Analytical Chemistry Laboratory

ERIC Educational Resources Information Center

Piunno, Paul A. E.; Zetina, Adrian; Chu, Norman; Tavares, Anthony J.; Noor, M. Omair; Petryayeva, Eleonora; Uddayasankar, Uvaraj; Veglio, Andrew

2014-01-01

An advanced analytical chemistry undergraduate laboratory module on microfluidics that spans 4 weeks (4 h per week) is presented. The laboratory module focuses on comprehensive experiential learning of microfluidic device fabrication and the core characteristics of microfluidic devices as they pertain to fluid flow and the manipulation of samples.…

Using Modern Solid-State Analytical Tools for Investigations of an Advanced Carbon Capture Material: Experiments for the Inorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Wriedt, Mario; Sculley, Julian P.; Aulakh, Darpandeep; Zhou, Hong-Cai

2016-01-01

A simple and straightforward synthesis of an ultrastable porous metal-organic framework (MOF) based on copper(II) and a mixed N donor ligand system is described as a laboratory experiment for chemistry undergraduate students. These experiments and the resulting analysis are designed to teach students basic research tools and procedures while…

Self-assembled hierarchically structured organic-inorganic composite systems.

PubMed

Tritschler, Ulrich; Cölfen, Helmut

2016-05-13

Designing bio-inspired, multifunctional organic-inorganic composite materials is one of the most popular current research objectives. Due to the high complexity of biocomposite structures found in nacre and bone, for example, a one-pot scalable and versatile synthesis approach addressing structural key features of biominerals and affording bio-inspired, multifunctional organic-inorganic composites with advanced physical properties is highly challenging. This article reviews recent progress in synthesizing organic-inorganic composite materials via various self-assembly techniques and in this context highlights a recently developed bio-inspired synthesis concept for the fabrication of hierarchically structured, organic-inorganic composite materials. This one-step self-organization concept based on simultaneous liquid crystal formation of anisotropic inorganic nanoparticles and a functional liquid crystalline polymer turned out to be simple, fast, scalable and versatile, leading to various (multi-)functional composite materials, which exhibit hierarchical structuring over several length scales. Consequently, this synthesis approach is relevant for further progress and scientific breakthrough in the research field of bio-inspired and biomimetic materials.

Mechanics and thermal management of stretchable inorganic electronics.

PubMed

Song, Jizhou; Feng, Xue; Huang, Yonggang

2016-03-01

Stretchable electronics enables lots of novel applications ranging from wearable electronics, curvilinear electronics to bio-integrated therapeutic devices that are not possible through conventional electronics that is rigid and flat in nature. One effective strategy to realize stretchable electronics exploits the design of inorganic semiconductor material in a stretchable format on an elastomeric substrate. In this review, we summarize the advances in mechanics and thermal management of stretchable electronics based on inorganic semiconductor materials. The mechanics and thermal models are very helpful in understanding the underlying physics associated with these systems, and they also provide design guidelines for the development of stretchable inorganic electronics.

Mechanics and thermal management of stretchable inorganic electronics

PubMed Central

Song, Jizhou; Feng, Xue; Huang, Yonggang

2016-01-01

Stretchable electronics enables lots of novel applications ranging from wearable electronics, curvilinear electronics to bio-integrated therapeutic devices that are not possible through conventional electronics that is rigid and flat in nature. One effective strategy to realize stretchable electronics exploits the design of inorganic semiconductor material in a stretchable format on an elastomeric substrate. In this review, we summarize the advances in mechanics and thermal management of stretchable electronics based on inorganic semiconductor materials. The mechanics and thermal models are very helpful in understanding the underlying physics associated with these systems, and they also provide design guidelines for the development of stretchable inorganic electronics. PMID:27547485

Recent advances in the fabrication and structure-specific applications of graphene-based inorganic hybrid membranes.

PubMed

Zhao, Xinne; Zhang, Panpan; Chen, Yuting; Su, Zhiqiang; Wei, Gang

2015-03-12

The preparation and applications of graphene (G)-based materials are attracting increasing interests due to their unique electronic, optical, magnetic, thermal, and mechanical properties. Compared to G-based hybrid and composite materials, G-based inorganic hybrid membrane (GIHM) offers enormous advantages ascribed to their facile synthesis, planar two-dimensional multilayer structure, high specific surface area, and mechanical stability, as well as their unique optical and mechanical properties. In this review, we report the recent advances in the technical fabrication and structure-specific applications of GIHMs with desirable thickness and compositions. In addition, the advantages and disadvantages of the methods utilized for creating GIHMs are discussed in detail. Finally, the potential applications and key challenges of GIHMs for future technical applications are mentioned.

Directed deposition of inorganic oxide networks on patterned polymer templates

NASA Astrophysics Data System (ADS)

Ford, Thomas James Robert

Inspired by nature, we have successfully directed the deposition of inorganic oxide materials on polymer templates via a combination of top-down and bottom-up fabrication methods. We have functionally mimicked the hierarchical silica exoskeletons of diatoms, where specialized proteins chaperone the condensation of silicic acid into nanoscale silica networks confined by microscopic vesicle walls. We replaced the proteins with functionally analogous polyamines and vesicles with lithographically defined polymer templates. We grafted the polyamines either to the surface or throughout the template by changing the template chemistry and altering our grafting strategy. Exposure to an inorganic oxide precursor solution led to electrostatic aggregation at the polyamine chains, catalyzing hydrolysis and condensation to form long-range inorganic oxide nanoparticle networks. Grafted to epoxy surfaces, swelling effects and the hyperbranched brush morphology lead to the formation of nanofruit features that generated thin, conformal inorganic coatings. When the polyamines were grafted throughout hydrogel templates, we obtained composite networks that yielded faithful inorganic replicas of the original patterns. By varying the polyamine chain length and combustion parameters, we controlled the nanoparticle size, morphology, and crystalline phase. The polyamine morphology affected the resulting inorganic network in both fabrication schemes and we could control the depostion over multiple length scales. Because our methods were compatible with a variety of lithographic methods, we were able to generate inorganic replicas of 1D, 2D, and 3D polymer structures. These may be used for a wide range of applications, including sensing, catalysis, photonic, phononic, photovoltaic, and others that require well-defined inorganic structures.

Equilibrium II: Acids and Bases. Independent Learning Project for Advanced Chemistry (ILPAC). Unit P3.

ERIC Educational Resources Information Center

Inner London Education Authority (England).

This unit on equilibrium is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, focuses on the application of equilibrium principles to equilibria involving weak acids and bases, including buffer solutions and indicators. Level one uses Le Chatelier's…

Inorganic Janus particles for biomedical applications

PubMed Central

Schick, Isabel; Lorenz, Steffen; Gehrig, Dominik; Tenzer, Stefan; Storck, Wiebke; Fischer, Karl; Strand, Dennis; Laquai, Frédéric

2014-01-01

Summary Based on recent developments regarding the synthesis and design of Janus nanoparticles, they have attracted increased scientific interest due to their outstanding properties. There are several combinations of multicomponent hetero-nanostructures including either purely organic or inorganic, as well as composite organic–inorganic compounds. Janus particles are interconnected by solid state interfaces and, therefore, are distinguished by two physically or chemically distinct surfaces. They may be, for instance, hydrophilic on one side and hydrophobic on the other, thus, creating giant amphiphiles revealing the endeavor of self-assembly. Novel optical, electronic, magnetic, and superficial properties emerge in inorganic Janus particles from their dimensions and unique morphology at the nanoscale. As a result, inorganic Janus nanoparticles are highly versatile nanomaterials with great potential in different scientific and technological fields. In this paper, we highlight some advances in the synthesis of inorganic Janus nanoparticles, focusing on the heterogeneous nucleation technique and characteristics of the resulting high quality nanoparticles. The properties emphasized in this review range from the monodispersity and size-tunability and, therefore, precise control over size-dependent features, to the biomedical application as theranostic agents. Hence, we show their optical properties based on plasmonic resonance, the two-photon activity, the magnetic properties, as well as their biocompatibility and interaction with human blood serum. PMID:25551063

Curriculum Outline for Introduction to Engineering Chemistry. Second Edition. Review Cycle-Annual.

ERIC Educational Resources Information Center

Schlenker, Richard M.

Introduction to Engineering Chemistry is a four-credit hour (one semester) course designed to introduce marine engineering students to the rudiments of basic (introductory) inorganic chemistry. The course consists of 18 units (numbered 1.0 through 18.0) focusing on these subject areas: fundamental concepts; structure of the atom and the periodic…

Synthesis and Structural Characterization of New Light Molecular Weight Inorganic Oxidizers and Related Derivatives. Volume: 2

DTIC Science & Technology

1993-02-01

of the strong inductive effect of the five fluorine ligands attached to the tellurium atom. 34 It is prepared under anhydrous conditions according to...MOLECULAR WEIGHT INORGANIC OXIDIZERS AND RELATED DERIVATIVES. VOLUME: II Professor G. J. Schrobilgen McMaster University Department of Chemistry...C: F04611-91-K-0004 Molecular Weight Inorganic Oxidizers and Relative PE: 62302F SDerivatives: Volume II 1PR: 5730 6. AUTHOFR(S) TA: 0*( C

Selection and Screening of DNA Aptamers for Inorganic Nanomaterials.

PubMed

Zhou, Yibo; Huang, Zhicheng; Yang, Ronghua; Liu, Juewen

2018-02-21

Searching for DNA sequences that can strongly and selectively bind to inorganic surfaces is a long-standing topic in bionanotechnology, analytical chemistry and biointerface research. This can be achieved either by aptamer selection starting with a very large library of ≈10 14 random DNA sequences, or by careful screening of a much smaller library (usually from a few to a few hundred) with rationally designed sequences. Unlike typical molecular targets, inorganic surfaces often have quite strong DNA adsorption affinities due to polyvalent binding and even chemical interactions. This leads to a very high background binding making aptamer selection difficult. Screening, on the other hand, can be designed to compare relative binding affinities of different DNA sequences and could be more appropriate for inorganic surfaces. The resulting sequences have been used for DNA-directed assembly, sorting of carbon nanotubes, and DNA-controlled growth of inorganic nanomaterials. It was recently discovered that poly-cytosine (C) DNA can strongly bind to a diverse range of nanomaterials including nanocarbons (graphene oxide and carbon nanotubes), various metal oxides and transition-metal dichalcogenides. In this Concept article, we articulate the need for screening and potential artifacts associated with traditional aptamer selection methods for inorganic surfaces. Representative examples of application are discussed, and a few future research opportunities are proposed towards the end of this article. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental and Theoretical Studies of Atmosphereic Inorganic Chlorine Chemistry

NASA Technical Reports Server (NTRS)

Sander, Stanley P.; Friedl, Randall R.

1993-01-01

Over the last five years substantial progress has been made in defining the realm of new chlorine chemistry in the polar stratosphere. Application of existing experimental techniques to potentially important chlorine-containing compounds has yielded quantitative kinetic and spectroscopic data as well as qualitative mechanistic insights into the relevant reactions.

ATR-FTIR Spectroscopy in the Undergraduate Chemistry Laboratory: Part II--A Physical Chemistry Laboratory Experiment on Surface Adsorption

ERIC Educational Resources Information Center

Schuttlefield, Jennifer D.; Larsen, Sarah C.; Grassian, Vicki H.

2008-01-01

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is a useful technique for measuring the infrared spectra of solids and liquids as well as probing adsorption on particle surfaces. The use of FTIR-ATR spectroscopy in organic and inorganic chemistry laboratory courses as well as in undergraduate research was presented…

Recent Development of Inorganic Nanoparticles for Biomedical Imaging

PubMed Central

2018-01-01

Inorganic nanoparticle-based biomedical imaging probes have been studied extensively as a potential alternative to conventional molecular imaging probes. Not only can they provide better imaging performance but they can also offer greater versatility of multimodal, stimuli-responsive, and targeted imaging. However, inorganic nanoparticle-based probes are still far from practical use in clinics due to safety concerns and less-optimized efficiency. In this context, it would be valuable to look over the underlying issues. This outlook highlights the recent advances in the development of inorganic nanoparticle-based probes for MRI, CT, and anti-Stokes shift-based optical imaging. Various issues and possibilities regarding the construction of imaging probes are discussed, and future research directions are suggested. PMID:29632878

Mass spectrometry. [in organic ion and biorganic chemistry and medicine

NASA Technical Reports Server (NTRS)

Burlingame, A. L.; Cox, R. E.; Derrick, P. J.

1974-01-01

Review of the present status of mass spectrometry in the light of pertinent recent publications spanning the period from December 1971 to January 1974. Following an initial survey of techniques, instruments, and computer applications, a sharp distinction is made between the chemistry of organic (radical-)ions and analytical applications in biorganic chemistry and medicine. The emphasis is on the chemistry of organic (radical-)ions at the expense of inorganic, organometallic, and surface ion chemistry. Biochemistry and medicine are chosen because of their contemporary importance and because of the stupendous contributions of mass spectroscopy to these fields in the past two years. In the review of gas-phase organic ion chemistry, special attention is given to studies making significant contributions to the understanding of ion chemistry.

A Quantum Chemistry Concept Inventory for Physical Chemistry Classes

ERIC Educational Resources Information Center

Dick-Perez, Marilu; Luxford, Cynthia J.; Windus, Theresa L.; Holme, Thomas

2016-01-01

A 14-item, multiple-choice diagnostic assessment tool, the quantum chemistry concept inventory or QCCI, is presented. Items were developed based on published student misconceptions and content coverage and then piloted and used in advanced physical chemistry undergraduate courses. In addition to the instrument itself, data from both a pretest,…

CHEMISTRY, A GUIDE FOR TEACHERS.

ERIC Educational Resources Information Center

WHEELER, HUBERT

THE VOLUME INCLUDES AN INTRODUCTION, THE COURSE CONTENT IN CHEMISTRY, AND FIVE APPENDIXES OF USEFUL INFORMATION. THE CHEMISTRY COURSE CONTENT IS FURTHER SUBDIVIDED INTO FIVE SECTIONS--(1) THE OVERVIEW, (2) CHEMICAL REACTIONS, (3) CHEMICAL BONDING AND MOLECULAR ARCHITECTURE, (4) DESCRIPTIVE CHEMISTRY, AND (5) ADVANCED CHEMISTRY. EACH OF THE FIVE…

AIEgens-Functionalized Inorganic-Organic Hybrid Materials: Fabrications and Applications.

PubMed

Li, Dongdong; Yu, Jihong

2016-12-01

Inorganic materials functionalized with organic fluorescent molecules combine advantages of them both, showing potential applications in biomedicine, chemosensors, light-emitting, and so on. However, when more traditional organic dyes are doped into the inorganic materials, the emission of resulting hybrid materials may be quenched, which is not conducive to the efficiency and sensitivity of detection. In contrast to the aggregation-caused quenching (ACQ) system, the aggregation-induced emission luminogens (AIEgens) with high solid quantum efficiency, offer new potential for developing highly efficient inorganic-organic hybrid luminescent materials. So far, many AIEgens have been incorporated into inorganic materials through either physical doping caused by aggregation induced emission (AIE) or chemical bonding (e.g., covalent bonding, ionic bonding, and coordination bonding) caused by bonding induced emission (BIE) strategy. The hybrid materials exhibit excellent photoactive properties due to the intramolecular motion of AIEgens is restricted by inorganic matrix. Recent advances in the fabrication of AIEgens-functionalized inorganic-organic hybrid materials and their applications in biomedicine, chemical sensing, and solid-state light emitting are presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Artificial inorganic biohybrids: The functional combination of microorganisms and cells with inorganic materials.

PubMed

Holzmeister, Ib; Schamel, Martha; Groll, Jürgen; Gbureck, Uwe; Vorndran, Elke

2018-04-24

Biohybrids can be defined as the functional combination of proteins, viable cells or microorganisms with non-biological materials. This article reviews recent findings on the encapsulation of microorganisms and eukaryotic cells in inorganic matrices such as silica gels or cements. The entrapment of biological entities into a support material is of great benefit for processing since the encapsulation matrix protects sensitive cells from shear forces, unfavourable pH changes, or cytotoxic solvents, avoids culture-washout, and simplifies the separation of formed products. After reflecting general aspects of such an immobilization as well as the chemistry of the inorganic matrices, we focused on manufacturing aspects and the application of such biohybrids in biotechnology, medicine as well as in environmental science and for civil engineering purpose. The encapsulation of living cells and microorganisms became an intensively studied and rapidly expanding research field with manifold applications in medicine, bio- and environmental technology, or civil engineering. Here, the use of silica or cements as encapsulation matrices have the advantage of a higher chemical and mechanical resistance towards harsh environmental conditions during processing compared to their polymeric counterparts. In this perspective, the article gives an overview about the inorganic material systems used for cell encapsulation, followed by reviewing the most important applications. The future may lay in a combination of the currently achieved biohybrid systems with additive manufacturing techniques. In a longer perspective, this would enable the direct printing of cell loaded bioreactor components. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Examination of the solution behaviors of the giant inorganic-organic amphiphilic hybrids

NASA Astrophysics Data System (ADS)

Zhang, Baofang

Presently, the self-assembly behaviors of traditional small surfactants and amphiphilic block copolymers are fairly well understood. In comparison, rather little is known about the self-assembly behaviors of the giant inorganic-organic amphiphilic hybrids in solution. It remains a wide open field to explore. Giant inorganic-organic amphiphilic hybrids, consisting of nanoscale inorganic clusters and organic functional groups, represent a novel class of functional hybrid materials. They have unique physical and chemical properties and potential applications in catalysis, electronic, optics, magnetic materials, medicine and biology. Therefore, as emerging building blocks, they have promising prospects in the advanced materials. In this PhD work, several representative giant inorganic-organic amphiphilic hybrids (triangular-shaped polyoxometalate (POM)-containing inorganic/organic amphiphilic hybrids, POM-containing fluorosurfactants hybrids, POM-containing peptide hybrids POM-peptide hybrids and polyhedral oligometric silsesquioxane (POSS)-polystyrene (PS) are chosen for studying their self-assembly behaviors in solution. Based on the knowledge of the physical chemistry, colloid and polymer science, we focus on the mechanism of the self-assembly process, and the morphology control of the supramolecular structures through the internal and external conditions, such as the composition of the giant amphiphilies, molecular architectures, solvent nature, temperature, concentration, and extrally added salts. It is found that the counterion-meditated interactions dominate the self-assembly of triangular-shaped hybrids in acetone/water mixed solutions, due to the highly dominant hydrophilic portions; the solvent-swelling effect, instead of the charge effect, dominates the whole self-assembly process of the POM-containing fluorosurfactants; the analogy between small surfactants and giant amphiphiles POSS-PS allows a rough assessment of the possible morphologies of the

Inorganic nanotubes: One contribution of 12 to a Theme 'Nanotechnology of carbon and related materials'

NASA Astrophysics Data System (ADS)

Tenne, Reshef; Rao, C. N. R.

2004-10-01

Following the discovery of carbon fullerenes and carbon nanotubes, it was hypothesized that nanoparticles of inorganic compounds with layered (two-dimensional) structure, such as MoS2, will not be stable against folding and form nanotubes and fullerene-like structures: IF. The synthesis of numerous other inorganic nanotubes has been reported in recent years. Various techniques for the synthesis of inorganic nanotubes, including high-temperature reactions and strategies based on 'chemie douce' (soft chemistry, i.e. low-temperature) processes, are described. First-principle, density functional theory based calculations are able to provide substantial information on the structure and properties of such nanotubes. Various properties of inorganic nanotubes, including mechanical, electronic and optical properties, are described in brief. Some potential applications of the nanotubes in tribology, protection against impact, (photo)catalysis, batteries, etc., are discussed.

Advances in understanding the surface chemistry of lignocellulosic biomass via time-of-flight secondary ion mass spectrometry

DOE PAGES

Tolbert, Allison K.; Ragauskas, Arthur J.

2016-12-12

Overcoming the natural recalcitrance of lignocellulosic biomass is necessary in order to efficiently convert biomass into biofuels or biomaterials and many times this requires some type of chemical pretreatment and/or biological treatment. While bulk chemical analysis is the traditional method of determining the impact a treatment has on biomass, the chemistry on the surface of the sample can differ from the bulk chemistry. Specifically, enzymes and microorganisms bind to the surface of the biomass and their efficiency could be greatly impacted by the chemistry of the surface. Therefore, it is important to study and understand the chemistry of the biomassmore » at the surface. Time-of- flight secondary ion mass spectrometry (ToF-SIMS) is a powerful tool that can spectrally and spatially analyze the surface chemistry of a sample. This review discusses the advances in understanding lignocellulosic biomass surface chemistry using the ToF-SIMS by addressing the instrument parameters, biomass sample preparation, and characteristic lignocellulosic ion fragmentation peaks along with their typical location in the plant cell wall. Furthermore, the use of the ToF-SIMS in detecting chemical changes due to chemical pretreatments, microbial treatments, and physical or genetic modifications is discussed along with possible future applications of the instrument in lignocellulosic biomass studies.« less

Advances in understanding the surface chemistry of lignocellulosic biomass via time-of-flight secondary ion mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tolbert, Allison K.; Ragauskas, Arthur J.

Overcoming the natural recalcitrance of lignocellulosic biomass is necessary in order to efficiently convert biomass into biofuels or biomaterials and many times this requires some type of chemical pretreatment and/or biological treatment. While bulk chemical analysis is the traditional method of determining the impact a treatment has on biomass, the chemistry on the surface of the sample can differ from the bulk chemistry. Specifically, enzymes and microorganisms bind to the surface of the biomass and their efficiency could be greatly impacted by the chemistry of the surface. Therefore, it is important to study and understand the chemistry of the biomassmore » at the surface. Time-of- flight secondary ion mass spectrometry (ToF-SIMS) is a powerful tool that can spectrally and spatially analyze the surface chemistry of a sample. This review discusses the advances in understanding lignocellulosic biomass surface chemistry using the ToF-SIMS by addressing the instrument parameters, biomass sample preparation, and characteristic lignocellulosic ion fragmentation peaks along with their typical location in the plant cell wall. Furthermore, the use of the ToF-SIMS in detecting chemical changes due to chemical pretreatments, microbial treatments, and physical or genetic modifications is discussed along with possible future applications of the instrument in lignocellulosic biomass studies.« less

Development of multiple regression analysis instruments to predict success in advanced placement chemistry

NASA Astrophysics Data System (ADS)

Wagner, Kurt Collins

2001-10-01

This research asks the fundamental question: "What is the profile of the successful AP chemistry student?" Two populations of students are studied. The first population is comprised of students who attend or attended the South Carolina Governor's School for Science and Mathematics, a specialized high school for high ability students, and who have taken the Advanced Placement (AP) chemistry examination in the past five years. The second population is comprised of the 581 South Carolina public school students at 46 high schools who took the AP chemistry examination in 2000. The first part of the study is intended to be useful in recruitment and placement decisions for schools in the National Consortium for Specialized Secondary Schools of Mathematics, Science and Technology. The second part of the study is intended to facilitate AP chemistry recruitment in South Carolina public schools. The first part of the study was conducted by ex post facto searches of teacher and school records at the South Carolina Governor's School for Science and Mathematics. The second part of the study was conducted by obtaining school participation information from the SC Department of Education and soliciting data from the public schools. Data were collected from 440 of 581 (75.7%) of students in 35 of 46 (76.1%) of schools. Intercorrelational and Multiple Regression Analyses (MRA) have yielded different results for these two populations. For the specialized school population, the significant predictors for success in AP chemistry are PSAT Math, placement test, and PSAT Writing. For the population of SC students, significant predictors for success are PSAT Math, count of prior science courses, and PSAT Writing. Multiple Regressions have been successfully developed for the two populations studied. Recommendations for their application are made.

Porous Inorganic Drug Delivery Systems-a Review.

PubMed

Sayed, E; Haj-Ahmad, R; Ruparelia, K; Arshad, M S; Chang, M-W; Ahmad, Z

2017-07-01

Innovative methods and materials have been developed to overcome limitations associated with current drug delivery systems. Significant developments have led to the use of a variety of materials (as excipients) such as inorganic and metallic structures, marking a transition from conventional polymers. Inorganic materials, especially those possessing significant porosity, are emerging as good candidates for the delivery of a range of drugs (antibiotics, anticancer and anti-inflammatories), providing several advantages in formulation and engineering (encapsulation of drug in amorphous form, controlled delivery and improved targeting). This review focuses on key selected developments in porous drug delivery systems. The review provides a short broad overview of porous polymeric materials for drug delivery before focusing on porous inorganic materials (e.g. Santa Barbara Amorphous (SBA) and Mobil Composition of Matter (MCM)) and their utilisation in drug dosage form development. Methods for their preparation and drug loading thereafter are detailed. Several examples of porous inorganic materials, drugs used and outcomes are discussed providing the reader with an understanding of advances in the field and realistic opportunities.

Clinical chemistry through Clinical Chemistry: a journal timeline.

PubMed

Rej, Robert

2004-12-01

The establishment of the modern discipline of clinical chemistry was concurrent with the foundation of the journal Clinical Chemistry and that of the American Association for Clinical Chemistry in the late 1940s and early 1950s. To mark the 50th volume of this Journal, I chronicle and highlight scientific milestones, and those within the discipline, as documented in the pages of Clinical Chemistry. Amazing progress has been made in the field of laboratory diagnostics over these five decades, in many cases paralleling-as well as being bolstered by-the rapid pace in the development of computer technologies. Specific areas of laboratory medicine particularly well represented in Clinical Chemistry include lipids, endocrinology, protein markers, quality of laboratory measurements, molecular diagnostics, and general advances in methodology and instrumentation.

Host-guest chemistry for tuning colloidal solubility, self-organization and photoconductivity of inorganic-capped nanocrystals

NASA Astrophysics Data System (ADS)

Bodnarchuk, Maryna I.; Yakunin, Sergii; Piveteau, Laura; Kovalenko, Maksym V.

2015-12-01

Colloidal inorganic nanocrystals (NCs), functionalized with inorganic capping ligands, such as metal chalcogenide complexes (MCCs), have recently emerged as versatile optoelectronic materials. As-prepared, highly charged MCC-capped NCs are dispersible only in highly polar solvents, and lack the ability to form long-range ordered NC superlattices. Here we report a simple and general methodology, based on host-guest coordination of MCC-capped NCs with macrocyclic ethers (crown ethers and cryptands), enabling the solubilization of inorganic-capped NCs in solvents of any polarity and improving the ability to form NC superlattices. The corona of organic molecules can also serve as a convenient knob for the fine adjustment of charge transport and photoconductivity in films of NCs. In particular, high-infrared-photon detectivities of up to 3.3 × 1011 Jones with a fast response (3 dB cut-off at 3 kHz) at the wavelength of 1,200 nm were obtained with films of PbS/K3AsS4/decyl-18-crown-6 NCs.

Reactivity II: A Second Foundation-Level Course in Integrated Organic, Inorganic, and Biochemistry

ERIC Educational Resources Information Center

Schaller, Chris P.; Graham, Kate J.; McIntee, Edward J.; Jones, T. Nicholas; Johnson, Brian J.

2016-01-01

A foundation-level course is described that integrates material related to reactivity in organic, inorganic, and biochemistry. Designed for second-year students, the course serves majors in chemistry, biochemistry, and biology, as well as prehealth-professions students. Building on an earlier course that developed concepts of nucleophiles and…

The thermodynamic scale of inorganic crystalline metastability

PubMed Central

Sun, Wenhao; Dacek, Stephen T.; Ong, Shyue Ping; Hautier, Geoffroy; Jain, Anubhav; Richards, William D.; Gamst, Anthony C.; Persson, Kristin A.; Ceder, Gerbrand

2016-01-01

The space of metastable materials offers promising new design opportunities for next-generation technological materials, such as complex oxides, semiconductors, pharmaceuticals, steels, and beyond. Although metastable phases are ubiquitous in both nature and technology, only a heuristic understanding of their underlying thermodynamics exists. We report a large-scale data-mining study of the Materials Project, a high-throughput database of density functional theory–calculated energetics of Inorganic Crystal Structure Database structures, to explicitly quantify the thermodynamic scale of metastability for 29,902 observed inorganic crystalline phases. We reveal the influence of chemistry and composition on the accessible thermodynamic range of crystalline metastability for polymorphic and phase-separating compounds, yielding new physical insights that can guide the design of novel metastable materials. We further assert that not all low-energy metastable compounds can necessarily be synthesized, and propose a principle of ‘remnant metastability’—that observable metastable crystalline phases are generally remnants of thermodynamic conditions where they were once the lowest free-energy phase. PMID:28138514

Crude oil in a shallow sand and gravel aquifer—I. Hydrogeology and inorganic geochemistry

USGS Publications Warehouse

Bennett, P.C.; Siegel, D.E.; Baedecker, M.J.; Hult, M.F.

1993-01-01

The observed changes in inorganic aqueous chemistry document changes in water-mineral interactions caused by the presence of an organic contaminant. These organic-initiated interactions are likely present in many contaminated aquifers and may be analogous to interactions occurring in other organic-rich natural waters.

Pure white-light emitting ultrasmall organic-inorganic hybrid perovskite nanoclusters.

PubMed

Teunis, Meghan B; Lawrence, Katie N; Dutta, Poulami; Siegel, Amanda P; Sardar, Rajesh

2016-10-14

Organic-inorganic hybrid perovskites, direct band-gap semiconductors, have shown tremendous promise for optoelectronic device fabrication. We report the first colloidal synthetic approach to prepare ultrasmall (∼1.5 nm diameter), white-light emitting, organic-inorganic hybrid perovskite nanoclusters. The nearly pure white-light emitting ultrasmall nanoclusters were obtained by selectively manipulating the surface chemistry (passivating ligands and surface trap-states) and controlled substitution of halide ions. The nanoclusters displayed a combination of band-edge and broadband photoluminescence properties, covering a major part of the visible region of the solar spectrum with unprecedentedly large quantum yields of ∼12% and photoluminescence lifetime of ∼20 ns. The intrinsic white-light emission of perovskite nanoclusters makes them ideal and low cost hybrid nanomaterials for solid-state lighting applications.

A Tiny Adventure: The Introduction of Problem Based Learning in an Undergraduate Chemistry Course

ERIC Educational Resources Information Center

Williams, Dylan P.; Woodward, Jonathan R.; Symons, Sarah L.; Davies, David L.

2010-01-01

Year 1 of the chemistry degree at the University of Leicester has been significantly changed by the integration of a problem based learning (PBL) component into the introductory inorganic/physical chemistry module, "Chemical Principles". Small groups of 5-6 students were given a series of problems with real world scenarios and were then…

Polymeric Biomaterials: Diverse Functions Enabled by Advances in Macromolecular Chemistry

PubMed Central

Liang, Yingkai; Li, Linqing; Scott, Rebecca A.; Kiick, Kristi L.

2017-01-01

Biomaterials have been extensively used to leverage beneficial outcomes in various therapeutic applications, such as providing spatial and temporal control over the release of therapeutic agents in drug delivery as well as engineering functional tissues and promoting the healing process in tissue engineering and regenerative medicine. This perspective presents important milestones in the development of polymeric biomaterials with defined structures and properties. Contemporary studies of biomaterial design have been reviewed with focus on constructing materials with controlled structure, dynamic functionality, and biological complexity. Examples of these polymeric biomaterials enabled by advanced synthetic methodologies, dynamic chemistry/assembly strategies, and modulated cell-material interactions have been highlighted. As the field of polymeric biomaterials continues to evolve with increased sophistication, current challenges and future directions for the design and translation of these materials are also summarized. PMID:29151616

Throwing the Book at Elementary Chemistry.

ERIC Educational Resources Information Center

Pauling, Linus

1983-01-01

Several examples of misinformation and advanced topics included in current chemistry textbooks are provided. Suggests that since these books tend to be too long, too advanced, and too heavy, revisions should be shorter and less costly, with confusing aspects of chemistry (such as molecular-orbital theory) left out completely. (JN)

Fluxes of inorganic carbon from two forested catchments in the Appalachian mountains

Treesearch

Fred Worrall; Wayne T. Swank; Tim Burt

2005-01-01

This study uses long-term records of stream chemistry, discharge and air temperature from two neighbouring forested catchments in the southern Appalachians in order to calculate production of dissolved C02 and dissolved inorganic carbon (DIC). One of the pair of catchments was clear-felled during the period of the study. The study shows that: (1...

Virus-based surface patterning of biological molecules, probes, and inorganic materials.

PubMed

Ahn, Suji; Jeon, Seongho; Kwak, Eun-A; Kim, Jong-Man; Jaworski, Justyn

2014-10-01

An essential requirement for continued technological advancement in many areas of biology, physics, chemistry, and materials science is the growing need to generate custom patterned materials. Building from recent achievements in the site-specific modification of virus for covalent surface tethering, we show in this work that stable 2D virus patterns can be generated in custom geometries over large area glass surfaces to yield templates of biological, biochemical, and inorganic materials in high density. As a nanomaterial building block, filamentous viruses have been extensively used in recent years to produce materials with interesting properties, owing to their ease of genetic and chemical modification. By utilizing un-natural amino acids generated at specific locations on the filamentous fd bacteriophage protein coat, surface immobilization is carried out on APTES patterned glass resulting in precise geometries of covalently linked virus material. This technique facilitated the surface display of a high density of virus that were labeled with biomolecules, fluorescent probes, and gold nanoparticles, thereby opening the possibility of integrating virus as functional components for surface engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

Exploring Undergraduates' Understanding of Transition Metals Chemistry with the Use of Cognitive and Confidence Measures

ERIC Educational Resources Information Center

Sreenivasulu, Bellam; Subramaniam, R.

2014-01-01

Compared to studies on school students' understanding of various topics in the sciences, studies involving university students have received relatively less attention in the science education literature. In this study, we investigated university students' understanding of transition metals chemistry, a topic in inorganic chemistry, which…

Host-guest chemistry for tuning colloidal solubility, self-organization and photoconductivity of inorganic-capped nanocrystals.

PubMed

Bodnarchuk, Maryna I; Yakunin, Sergii; Piveteau, Laura; Kovalenko, Maksym V

2015-12-09

Colloidal inorganic nanocrystals (NCs), functionalized with inorganic capping ligands, such as metal chalcogenide complexes (MCCs), have recently emerged as versatile optoelectronic materials. As-prepared, highly charged MCC-capped NCs are dispersible only in highly polar solvents, and lack the ability to form long-range ordered NC superlattices. Here we report a simple and general methodology, based on host-guest coordination of MCC-capped NCs with macrocyclic ethers (crown ethers and cryptands), enabling the solubilization of inorganic-capped NCs in solvents of any polarity and improving the ability to form NC superlattices. The corona of organic molecules can also serve as a convenient knob for the fine adjustment of charge transport and photoconductivity in films of NCs. In particular, high-infrared-photon detectivities of up to 3.3 × 10(11) Jones with a fast response (3 dB cut-off at 3 kHz) at the wavelength of 1,200 nm were obtained with films of PbS/K3AsS4/decyl-18-crown-6 NCs.

Host–guest chemistry for tuning colloidal solubility, self-organization and photoconductivity of inorganic-capped nanocrystals

PubMed Central

Bodnarchuk, Maryna I.; Yakunin, Sergii; Piveteau, Laura; Kovalenko, Maksym V.

2015-01-01

Colloidal inorganic nanocrystals (NCs), functionalized with inorganic capping ligands, such as metal chalcogenide complexes (MCCs), have recently emerged as versatile optoelectronic materials. As-prepared, highly charged MCC-capped NCs are dispersible only in highly polar solvents, and lack the ability to form long-range ordered NC superlattices. Here we report a simple and general methodology, based on host–guest coordination of MCC-capped NCs with macrocyclic ethers (crown ethers and cryptands), enabling the solubilization of inorganic-capped NCs in solvents of any polarity and improving the ability to form NC superlattices. The corona of organic molecules can also serve as a convenient knob for the fine adjustment of charge transport and photoconductivity in films of NCs. In particular, high-infrared-photon detectivities of up to 3.3 × 1011 Jones with a fast response (3 dB cut-off at 3 kHz) at the wavelength of 1,200 nm were obtained with films of PbS/K3AsS4/decyl-18-crown-6 NCs. PMID:26647828

Analytical Chemistry Division annual progress report for period ending December 31, 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shultz, W.D.

1986-05-01

Progress reports are presented for the four major sections of the division: analytical spectroscopy, radioactive materials laboratories, inorganic chemistry, and organic chemistry. A brief discussion of the division's role in the Laboratory's Environmental Restoration and Facilities Upgrade is given. Information about quality assurance and safety programs is presented, along with a tabulation of analyses rendered. Publications, oral presentations, professional activities, educational programs, and seminars are cited.

Advances in the Biology and Chemistry of Sialic Acids

PubMed Central

Chen, Xi; Varki, Ajit

2010-01-01

Sialic acids are a subset of nonulosonic acids, which are nine-carbon alpha-keto aldonic acids. Natural existing sialic acid-containing structures are presented in different sialic acid forms, various sialyl linkages, and on diverse underlying glycans. They play important roles in biological, pathological, and immunological processes. Sialobiology has been a challenging and yet attractive research area. Recent advances in chemical and chemoenzymatic synthesis as well as large-scale E. coli cell-based production have provided a large library of sialoside standards and derivatives in amounts sufficient for structure-activity relationship studies. Sialoglycan microarrays provide an efficient platform for quick identification of preferred ligands for sialic acid-binding proteins. Future research on sialic acid will continue to be at the interface of chemistry and biology. Research efforts will not only lead to a better understanding of the biological and pathological importance of sialic acids and their diversity, but could also lead to the development of therapeutics. PMID:20020717

Incorporating Sustainability and Life Cycle Assessment into First-Year Inorganic Chemistry Major Laboratories

ERIC Educational Resources Information Center

Guron, Marta; Paul, Jared J.; Roeder, Margaret H.

2016-01-01

Although much of the scientific community concerns itself with ideas of a sustainable future, very little of this interest and motivation has reached the classroom experience of the average chemistry major, and therefore, it is imperative to expose students to these ideas early in their careers. The focus of most undergraduate chemistry curricula…

Using an Advanced Computational Laboratory Experiment to Extend and Deepen Physical Chemistry Students' Understanding of Atomic Structure

ERIC Educational Resources Information Center

Hoffman, Gary G.

2015-01-01

A computational laboratory experiment is described, which involves the advanced study of an atomic system. The students use concepts and techniques typically covered in a physical chemistry course but extend those concepts and techniques to more complex situations. The students get a chance to explore the study of atomic states and perform…

Oxidation Kinetics of Copper: An Experiment in Solid State Chemistry.

ERIC Educational Resources Information Center

Ebisuzaki, Y.; Sanborn, W. B.

1985-01-01

Oxidation kinetics in metals and the role defects play in diffusion-controlled reactions are discussed as background for a junior/senior-level experiment in the physical or inorganic chemistry laboratory. Procedures used and typical data obtained are provided for the experiment. (JN)

Temporal and spatial variation in major ion chemistry and source identification of secondary inorganic aerosols in Northern Zhejiang Province, China.

PubMed

Xu, Jing-Sha; Xu, Meng-Xia; Snape, Colin; He, Jun; Behera, Sailesh N; Xu, Hong-Hui; Ji, Dong-Sheng; Wang, Cheng-Jun; Yu, Huan; Xiao, Hang; Jiang, Yu-Jun; Qi, Bing; Du, Rong-Guang

2017-07-01

To investigate the seasonal and spatial variations of ion chemistry of fine particles in Northern Zhejiang Province (NZP), China, one year-long field sampling was conducted at four representative sites (two urban, one suburb, and one rural sites) in both cities of Hangzhou and Ningbo from December 2014 to November 2015. Twelve water soluble inorganic ions (WSII) were characterized in this comprehensive study. The annual average of PM 2.5 concentration in NZP as overall was 66.2 ± 37.7 μg m -3 , and urban sites in NZP were observed with more severe PM 2.5 pollution than the suburban and rural sites. The annual average concentration of total WSII at four sampling sites in NZP was 29.1 ± 19.9 μg m -3 , dominated by SO 4 2- (10.3 μg m -3 ), and followed by NO 3 - (8.9 μg m -3 ), NH 4 + (6.6 μg m -3 ), Cl - (1.3 μg m -3 ) and K + (0.7 μg m -3 ). Among all cations, NH 4 + was the predominant neutralizing ion with the highest neutralization factor (NF), while the remaining cations showed limited neutralization capacity. The highest and lowest sulfur oxidation ratio (SOR) values in this region were found in summer and winter, respectively; while the seasonal patterns for nitrogen oxidation ratio (NOR) were opposite to that of SOR. Principal component analysis (PCA) showed that the significant sources of WSII in NZP were industrial emissions, biomass burning, and formation of secondary inorganic aerosols. In addition, contribution from transboundary transport of polluted aerosols was also confirmed from the assessment through air mass backward trajectory analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cobalt complexes as internal standards for capillary zone electrophoresis-mass spectrometry studies in biological inorganic chemistry.

PubMed

Holtkamp, Hannah U; Morrow, Stuart J; Kubanik, Mario; Hartinger, Christian G

2017-07-01

Run-by-run variations are very common in capillary electrophoretic (CE) separations and cause imprecision in both the migration times and the peak areas. This makes peak and kinetic trend identification difficult and error prone. With the aim to identify suitable standards for CE separations which are compatible with the common detectors UV, ESI-MS, and ICP-MS, the Co III complexes [Co(en) 3 ]Cl 3 , [Co(acac) 3 ] and K[Co(EDTA)] were evaluated as internal standards in the reaction of the anticancer drug cisplatin and guanosine 5'-monophosphate as an example of a classical biological inorganic chemistry experiment. These Co III chelate complexes were considered for their stability, accessibility, and the low detection limit for Co in ICP-MS. Furthermore, the Co III complexes are positively and negatively charged as well as neutral, allowing the detection in different areas of the electropherograms. The background electrolytes were chosen to cover a wide pH range. The compatibility to the separation conditions was dependent on the ligands attached to the Co III centers, with only the acetylacetonato (acac) complex being applicable in the pH range 2.8-9.0. Furthermore, because of being charge neutral, this compound could be used as an electroosmotic flow (EOF) marker. In general, employing Co complexes resulted in improved data sets, particularly with regard to the migration times and peak areas, which resulted, for example, in higher linear ranges for the quantification of cisplatin.

Inorganic carbon speciation and fluxes in the Congo River

NASA Astrophysics Data System (ADS)

Wang, Zhaohui Aleck; Bienvenu, Dinga Jean; Mann, Paul J.; Hoering, Katherine A.; Poulsen, John R.; Spencer, Robert G. M.; Holmes, Robert M.

2013-02-01

Seasonal variations in inorganic carbon chemistry and associated fluxes from the Congo River were investigated at Brazzaville-Kinshasa. Small seasonal variation in dissolved inorganic carbon (DIC) was found in contrast with discharge-correlated changes in pH, total alkalinity (TA), carbonate species, and dissolved organic carbon (DOC). DIC was almost always greater than TA due to the importance of CO2*, the sum of dissolved CO2 and carbonic acid, as a result of low pH. Organic acids in DOC contributed 11-61% of TA and had a strong titration effect on water pH and carbonate speciation. The CO2* and bicarbonate fluxes accounted for ~57% and 43% of the DIC flux, respectively. Congo River surface water released CO2 at a rate of ~109 mol m-2 yr-1. The basin-wide DIC yield was ~8.84 × 104 mol km-2 yr-1. The discharge normalized DIC flux to the ocean amounted to 3.11 × 1011 mol yr-1. The DOC titration effect on the inorganic carbon system may also be important on a global scale for regulating carbon fluxes in rivers.

A Laboratory Exercise to Introduce Inorganic Biomimetic Compounds.

ERIC Educational Resources Information Center

Baird, Donald M.

1985-01-01

Biomimetic chemistry is concerned with the synthesis of small, molecular weight molecules which mimic the properties of metal-containing sites within certain biologically significant species. A series of experiments for an advanced undergraduate laboratory is described as a way to introduce this area into the chemistry curriculum. (JN)

Bioinorganic Life and Neural Activity: Toward a Chemistry of Consciousness?

PubMed

Chang, Christopher J

2017-03-21

Identifying what elements are required for neural activity as potential path toward consciousness, which represents life with the state or quality of awareness, is a "Holy Grail" of chemistry. As life itself arises from coordinated interactions between elements across the periodic table, the majority of which are metals, new approaches for analysis, binding, and control of these primary chemical entities can help enrich our understanding of inorganic chemistry in living systems in a context that is both universal and personal.

Inorganic Photovoltaics Materials and Devices: Past, Present, and Future

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Bailey, Sheila G.; Rafaelle, Ryne P.

2005-01-01

This report describes recent aspects of advanced inorganic materials for photovoltaics or solar cell applications. Specific materials examined will be high-efficiency silicon, gallium arsenide and related materials, and thin-film materials, particularly amorphous silicon and (polycrystalline) copper indium selenide. Some of the advanced concepts discussed include multi-junction III-V (and thin-film) devices, utilization of nanotechnology, specifically quantum dots, low-temperature chemical processing, polymer substrates for lightweight and low-cost solar arrays, concentrator cells, and integrated power devices. While many of these technologies will eventually be used for utility and consumer applications, their genesis can be traced back to challenging problems related to power generation for aerospace and defense. Because this overview of inorganic materials is included in a monogram focused on organic photovoltaics, fundamental issues and metrics common to all solar cell devices (and arrays) will be addressed.

Interaction of inorganic anions with iron-mineral adsorbents in aqueous media--a review.

PubMed

Kumar, Eva; Bhatnagar, Amit; Hogland, William; Marques, Marcia; Sillanpää, Mika

2014-01-01

A number of inorganic anions (e.g., nitrate, fluoride, bromate, phosphate, and perchlorate) have been reported in alarming concentrations in numerous drinking water sources around the world. Their presence even in very low concentrations may cause serious environmental and health related problems. Due to the presence and significance of iron minerals in the natural aquatic environment and increasing application of iron in water treatment, the knowledge of the structure of iron and iron minerals and their interactions with aquatic pollutants, especially inorganic anions in water are of great importance. Iron minerals have been known since long as potential adsorbents for the removal of inorganic anions from aqueous phase. The chemistry of iron and iron minerals reactions in water is complex. The adsorption ability of iron and iron minerals towards inorganic anions is influenced by several factors such as, surface characteristics of the adsorbent (surface area, density, pore volume, porosity, pore size distribution, pHpzc, purity), pH of the solution, and ionic strength. Furthermore, the physico-chemical properties of inorganic anions (pore size, ionic radius, bulk diffusion coefficient) also significantly influence the adsorption process. The aim of this paper is to provide an overview of the properties of iron and iron minerals and their reactivity with some important inorganic anionic contaminants present in water. It also summarizes the usage of iron and iron minerals in water treatment technology. © 2013.

Polypropylene/glass fiber hierarchical composites incorporating inorganic fullerene-like nanoparticles for advanced technological applications.

PubMed

Díez-Pascual, Ana M; Naffakh, Mohammed

2013-10-09

Novel isotactic polypropylene (iPP)/glass fiber (GF) laminates reinforced with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles as environmentally friendly fillers have been successfully fabricated by simple melt-blending and fiber impregnation in a hot-press without the addition of any compatibilizer. The influence of IF-WS2 concentration on the morphology, viscosity. and thermal and mechanical behavior of the hierarchical composites has been investigated. Results revealed an unprecedented 62 °C increase in the degradation temperature of iPP/GF upon addition of only 4.0 wt % IF-WS2. The coexistence of both micro- and nanoscale fillers resulted in synergistic effects on enhancing the stiffness, strength, crystallinity, thermal stability, glass transition (Tg) and heat distortion temperature (HDT) of the matrix. The approach used in this work is an efficient, versatile, scalable and economic strategy to improve the mechanical and thermal behavior of GF-reinforced thermoplastics with a view to extend their use in advanced technological applications. This new type of composite materials shows great potential to improve the efficiency and sustainability of many forms of transport.

POREWATER CHEMISTRY: EFFECTS OF SAMPLING, STORAGE, HANDLING, AND TOXICITY TESTING

EPA Science Inventory

As a general principle, it is nearly impossible to remove a porewater sample from sediment, use it in a toxicity testing vessel with test organisms, and prevent changes in the chemistry of the natural and anthropogenic organic and inorganic constituents. The degree of change in t...

Teaching Inorganic Photophysics and Photochemistry with Three Ruthenium(II) Polypyridyl Complexes: A Computer-Based Exercise

ERIC Educational Resources Information Center

Garino, Claudio; Terenzi, Alessio; Barone, Giampaolo; Salassa, Luca

2016-01-01

Among computational methods, DFT (density functional theory) and TD-DFT (time-dependent DFT) are widely used in research to describe, "inter alia," the optical properties of transition metal complexes. Inorganic/physical chemistry courses for undergraduate students treat such methods, but quite often only from the theoretical point of…

Organic-inorganic hybrid mesoporous silicas: functionalization, pore size, and morphology control.

PubMed

Park, Sung Soo; Ha, Chang-Sik

2006-01-01

Topological design of mesoporous silica materials, pore architecture, pore size, and morphology are currently major issues in areas such as catalytic conversion of bulky molecules, adsorption, host-guest chemistry, etc. In this sense, we discuss the pore size-controlled mesostructure, framework functionalization, and morphology control of organic-inorganic hybrid mesoporous silicas by which we can improve the applicability of mesoporous materials. First, we explain that the sizes of hexagonal- and cubic-type pores in organic-inorganic hybrid mesoporous silicas are well controlled from 24.3 to 98.0 A by the direct micelle-control method using an organosilica precursor and surfactants with different alkyl chain lengths or triblock copolymers as templates and swelling agents incorporated in the formed micelles. Second, we describe that organic-inorganic hybrid mesoporous materials with various functional groups form various external morphologies such as rod, cauliflower, film, rope, spheroid, monolith, and fiber shapes. Third, we discuss that transition metals (Ti and Ru) and rare-earth ions (Eu(3+) and Tb(3+)) are used to modify organic-inorganic hybrid mesoporous silica materials. Such hybrid mesoporous silica materials are expected to be applied as excellent catalysts for organic reactions, photocatalysis, optical devices, etc. c) 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Synthesis of inorganic polymers using fly ash and primary lead slag.

PubMed

Onisei, S; Pontikes, Y; Van Gerven, T; Angelopoulos, G N; Velea, T; Predica, V; Moldovan, P

2012-02-29

The present work reports on the synthesis and properties of inorganic polymers ("geopolymers") made of 100% fly ash from lignite's combustion, 100% primary lead slag and mixtures of the two. In the inorganic polymers with both fly ash and lead slag the main crystalline phases detected are wüstite, magnetite, sodium zinc silicate, quartz, anorthite, and gehlenite; litharge partially dissolves. FTIR analysis in these samples revealed that the main peaks and bands of end members also exist, along with a new amorphous reaction product. In terms of microstructure, both fly ash and lead slag dissolve and contribute in the binding phase whereas the larger particles act as aggregates. For an increasing lead slag in the composition, the binding phase is changing in chemistry and reaches PbO values higher than 50 wt.% for the 100% lead slag inorganic polymer. Regarding the properties of fly ash and lead slag inorganic polymers, compressive strength is higher than 35 MPa in all cases and water absorption diminishes as the lead slag content increases. A comparison of leaching results before and after polymerisation reveals that pH is an important factor as Pb is immobilised in the binding phase, unlike Zn and As. Copyright © 2011 Elsevier B.V. All rights reserved.

Chemistry in Microfluidic Channels

ERIC Educational Resources Information Center

Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

2011-01-01

General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

Constraining wintertime sources of inorganic chlorine over the northeast United States

NASA Astrophysics Data System (ADS)

Haskins, J.; Jaegle, L.; Shah, V.; Lopez-Hilfiker, F.; Lee, B. H.; Campuzano Jost, P.; Schroder, J. C.; Day, D. A.; Fiddler, M. N.; Holloway, J. S.; Sullivan, A.; Veres, P. R.; Weber, R. J.; Dibb, J. E.; Brown, S. S.; Jimenez, J. L.; Thornton, J. A.

2017-12-01

Wintertime multiphase chlorine chemistry is thought to play a significant role in the regional distribution of oxidants, the lifetime of VOCs, and the transport of NOx downwind of urban sources. However, the sources and chemistry of reactive chlorine remain highly uncertain. During the WINTER 2015 aircraft campaign, the inorganic chlorine budget was dominated by HCl (g) and total particulate chloride, accounting for greater than 85% of the total chlorine budget within the boundary layer. The total concentration of inorganic chlorine compounds found over marine regions was 1014 pptv and 609 pptv over continental regions with variability found to be driven by changes in meteorological conditions, particle liquid water content, particle pH, and proximity to large anthropogenic sources. However, displacement of particle chloride was often not a large enough source to fully explain the concentrations of gas phase Cly compounds. We use the GEOS-Chem global chemical transport model to simulate the emissions, gas-particle partitioning, and downwind transport and deposition of Cly during winter. Simulated concentrations of HCl, particle chloride, and other dominant Cly compounds are compared to measurements made during the WINTER aircraft campaign. The relative roles of Cly sources from sea-salt aerosol and anthropogenic sources such as power plants, biomass burning and road salt are explored.

Emerging of Inorganic Hole Transporting Materials For Perovskite Solar Cells.

PubMed

Rajeswari, Ramireddy; Mrinalini, Madoori; Prasanthkumar, Seelam; Giribabu, Lingamallu

2017-07-01

Hole transporting material (HTM) is a significant component to achieve the high performance perovskite solar cells (PSCs). Over the years, inorganic, organic and hybrid (organic-inorganic) material based HTMs have been developed and investigated successfully. Today, perovskite solar cells achieved the efficiency of 22.1 % with with 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine) 9,9-spirobifluorene (spiro-OMeTAD) as HTM. Nevertheless, synthesis and cost of organic HTMs is a major challenging issue and therefore alternative materials are required. From the past few years, inorganic HTMs showed large improvement in power conversion efficiency (PCE) and stability. Recently CuO x reached the PCE of 19.0% with better stability. These developments affirms that inorganic HTMs are better alternativesto the organic HTMs for next generation PSCs. In this report, we mainly focussed on the recent advances of inorganic and hybrid HTMs for PSCs and highlighted the efficiency and stability of PSCs improved by changing metal oxides as HTMs. Consequently, we expect that energy levels of these inorganic HTMs matches very well with the valence band of perovskites and improved efficiency helps in future practical deployment of low cost PSCs. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multifunctional Inorganic Nanoparticles: Recent Progress in Thermal Therapy and Imaging

PubMed Central

Cherukula, Kondareddy; Manickavasagam Lekshmi, Kamali; Uthaman, Saji; Cho, Kihyun; Cho, Chong-Su; Park, In-Kyu

2016-01-01

Nanotechnology has enabled the development of many alternative anti-cancer approaches, such as thermal therapies, which cause minimal damage to healthy cells. Current challenges in cancer treatment are the identification of the diseased area and its efficient treatment without generating many side effects. Image-guided therapies can be a useful tool to diagnose and treat the diseased tissue and they offer therapy and imaging using a single nanostructure. The present review mainly focuses on recent advances in the field of thermal therapy and imaging integrated with multifunctional inorganic nanoparticles. The main heating sources for heat-induced therapies are the surface plasmon resonance (SPR) in the near infrared region and alternating magnetic fields (AMFs). The different families of inorganic nanoparticles employed for SPR- and AMF-based thermal therapies and imaging are described. Furthermore, inorganic nanomaterials developed for multimodal therapies with different and multi-imaging modalities are presented in detail. Finally, relevant clinical perspectives and the future scope of inorganic nanoparticles in image-guided therapies are discussed. PMID:28335204

Reactivity III: An Advanced Course in Integrated Organic, Inorganic, and Biochemistry

ERIC Educational Resources Information Center

Schaller, Chris P.; Graham, Kate J.; Jakubowski, Henry V.

2017-01-01

Reactivity III is a new course that presents chemical reactions from the domains of organic, inorganic, and biochemistry that are not readily categorized by electrophile-nucleophile interactions. Many of these reactions involve the transfer of a single electron, in either an intermolecular fashion in the case of oxidation/reduction reactions or an…

Virtually going green: The role of quantum computational chemistry in reducing pollution and toxicity in chemistry

NASA Astrophysics Data System (ADS)

Stevens, Jonathan

2017-07-01

Continuing advances in computational chemistry has permitted quantum mechanical calculation to assist in research in green chemistry and to contribute to the greening of chemical practice. Presented here are recent examples illustrating the contribution of computational quantum chemistry to green chemistry, including the possibility of using computation as a green alternative to experiments, but also illustrating contributions to greener catalysis and the search for greener solvents. Examples of applications of computation to ambitious projects for green synthetic chemistry using carbon dioxide are also presented.

Physics-informed machine learning for inorganic scintillator discovery

NASA Astrophysics Data System (ADS)

Pilania, G.; McClellan, K. J.; Stanek, C. R.; Uberuaga, B. P.

2018-06-01

Applications of inorganic scintillators—activated with lanthanide dopants, such as Ce and Eu—are found in diverse fields. As a strict requirement to exhibit scintillation, the 4f ground state (with the electronic configuration of [Xe]4fn 5d0) and 5d1 lowest excited state (with the electronic configuration of [Xe]4fn-1 5d1) levels induced by the activator must lie within the host bandgap. Here we introduce a new machine learning (ML) based search strategy for high-throughput chemical space explorations to discover and design novel inorganic scintillators. Building upon well-known physics-based chemical trends for the host dependent electron binding energies within the 4f and 5d1 energy levels of lanthanide ions and available experimental data, the developed ML model—coupled with knowledge of the vacuum referred valence and conduction band edges computed from first principles—can rapidly and reliably estimate the relative positions of the activator's energy levels relative to the valence and conduction band edges of any given host chemistry. Using perovskite oxides and elpasolite halides as examples, the presented approach has been demonstrated to be able to (i) capture systematic chemical trends across host chemistries and (ii) effectively screen promising compounds in a high-throughput manner. While a number of other application-specific performance requirements need to be considered for a viable scintillator, the scheme developed here can be a practically useful tool to systematically down-select the most promising candidate materials in a first line of screening for a subsequent in-depth investigation.

Extraordinary plasticity of an inorganic semiconductor in darkness.

PubMed

Oshima, Yu; Nakamura, Atsutomo; Matsunaga, Katsuyuki

2018-05-18

Inorganic semiconductors generally tend to fail in a brittle manner. Here, we report that extraordinary "plasticity" can take place in an inorganic semiconductor if the deformation is carried out "in complete darkness." Room-temperature deformation tests of zinc sulfide (ZnS) were performed under varying light conditions. ZnS crystals immediately fractured when they deformed under light irradiation. In contrast, it was found that ZnS crystals can be plastically deformed up to a deformation strain of ε t = 45% in complete darkness. In addition, the optical bandgap of the deformed ZnS crystals was distinctly decreased after deformation. These results suggest that dislocations in ZnS become mobile in complete darkness and that multiplied dislocations can affect the optical bandgap over the whole crystal. Inorganic semiconductors are not necessarily intrinsically brittle. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Bioorganic and bioinorganic chemistry.

PubMed

Constable, Edwin C; Housecroft, Catherine E; Creus, Marc; Gademann, Karl; Giese, Bernd; Ward, Thomas R; Woggon, Wolf D; Chougnet, Antoinette

2010-01-01

The interdisciplinary projects in bioinorganic and bioorganic chemistry of the Department of Chemistry, University of Basel led to the preparation of new systems that mimic biologically important processes and to the discovery of compounds from natural sources which are very promising with respect to medical applications. The advances in these areas are reported here.

Mineral-Enhanced Polyacrylic Acid Hydrogel as an Oyster-Inspired Organic-Inorganic Hybrid Adhesive.

PubMed

Li, Ang; Jia, Yunfei; Sun, Shengtong; Xu, Yisheng; Minsky, Burcu Baykal; Stuart, M A Cohen; Cölfen, Helmut; von Klitzing, Regine; Guo, Xuhong

2018-03-28

Underwater adhesion is crucial to many marine life forms living a sedentary lifestyle. Amongst them, mussel adhesion has been mostly studied, which inspires numerous investigations of 3,4-dihydroxyphenylalanine (DOPA)-based organic adhesives. In contrast, reef-building oysters represent another important "inorganic" strategy of marine molluscs for adhesion by generating biomineralized organic-inorganic adhesives, which is still rarely studied and no synthetic analogues have ever been reported so far. Here, a novel type of oyster-inspired organic-inorganic adhesive based on a biomineralized polyelectrolyte hydrogel is reported, which consists of polyacrylic acid physically cross-linked by very small amorphous calcium carbonate nanoparticles (<3 nm). The mineral-enhanced polyelectrolyte hydrogel adhesive is shown to be injectable, reusable, and optically clear upon curing in air. Moreover, comparable adhesion performance to DOPA-based adhesives is found for the hydrogel adhesive in both dry and wet conditions, which can even be further enhanced by introducing a small amount of second large cross-linker such as negatively charged nanoparticles. The present mineral hydrogel represents a new type of bio-inspired organic-inorganic adhesive that may find a variety of potential applications in adhesive chemistry.

Biomineralization of unicellular organisms: an unusual membrane biochemistry for the production of inorganic nano- and microstructures.

PubMed

Bäuerlein, Edmund

2003-02-10

With evolution, Nature has ingeniously succeeded in giving rise to an impressive variety of inorganic structures. Every organism that synthesizes biogenic minerals does so in a form that is unique to that species. This biomineralization is apparently biologically controlled. It is thus expected that both the synthesis and the form of every specific biogenic mineral is genetically determined and controlled. An investigation of the mechanism of biomineralization has only become possible with the development of modern methods in molecular biology. Unicellular organisms such as magnetic bacteria, calcareous algae, and diatoms, all of which are amongst the simplest forms of life, are particularly suited to be investigated by these methods. Crystals and composites of proteins and amorphous inorganic polymers are formed as complex structures within these organisms; these structures are not known in conventional inorganic chemistry.

Casting inorganic structures with DNA molds.

PubMed

Sun, Wei; Boulais, Etienne; Hakobyan, Yera; Wang, Wei Li; Guan, Amy; Bathe, Mark; Yin, Peng

2014-11-07

We report a general strategy for designing and synthesizing inorganic nanostructures with arbitrarily prescribed three-dimensional shapes. Computationally designed DNA strands self-assemble into a stiff "nanomold" that contains a user-specified three-dimensional cavity and encloses a nucleating gold "seed." Under mild conditions, this seed grows into a larger cast structure that fills and thus replicates the cavity. We synthesized a variety of nanoparticles with 3-nanometer resolution: three distinct silver cuboids with three independently tunable dimensions, silver and gold nanoparticles with diverse cross sections, and composite structures with homo- and heterogeneous components. The designer equilateral silver triangular and spherical nanoparticles exhibited plasmonic properties consistent with electromagnetism-based simulations. Our framework is generalizable to more complex geometries and diverse inorganic materials, offering a range of applications in biosensing, photonics, and nanoelectronics. Copyright © 2014, American Association for the Advancement of Science.

Microwave-Assisted Chemistry: Synthetic Applications for Rapid Assembly of Nanomaterials and Organics

EPA Science Inventory

The magic of microwave (MW) heating technique, termed as the Bunsen burner of the 21th Century, has emerged as valuable alternative in synthesis of organics, polymers, inorganics, and nanomaterials. Important innovations in MW-assisted chemistry now enable chemists to prepare cat...

Matrices for Sensors from Inorganic, Organic, and Biological Nanocomposites

PubMed Central

Nicolini, Claudio; Sivozhelezov, Victor; Bavastrello, Valter; Bezzerra, Tercio; Scudieri, Dora; Spera, Rosanna; Pechkova, Eugenia

2011-01-01

Matrices and sensors resulting from inorganic, organic and biological nanocomposites are presented in this overview. The term nanocomposite designates a solid combination of a matrix and of nanodimensional phases differing in properties from the matrix due to dissimilarities in structure and chemistry. The nanoocomposites chosen for a wide variety of health and environment sensors consist of Anodic Porous Allumina and P450scc, Carbon nanotubes and Conductive Polymers, Langmuir Blodgett Films of Lipases, Laccases, Cytochromes and Rhodopsins, Three-dimensional Nanoporous Materials and Nucleic Acid Programmable Protein Arrays. PMID:28824154

Impact of seawater carbonate chemistry on the calcification of marine bivalves

NASA Astrophysics Data System (ADS)

Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

2015-07-01

Bivalve calcification, particularly of the early larval stages, is highly sensitive to the change in ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no effects and [HCO3-] and pH had only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. An equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the mechanisms that limit or facilitate adaptation to future ocean acidification, it is necessary to better

Impact of seawater carbonate chemistry on the calcification of marine bivalves

NASA Astrophysics Data System (ADS)

Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

2015-01-01

Bivalve calcification, particular of the early larval stages is highly sensitive to the change of ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no and [HCO3-] and pH only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. Therefore, the availability of [HCO3-] combined with favorable environmental pH determines calcification rate and an equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the

International year of Chemistry 2011. A guide to the history of clinical chemistry.

PubMed

Kricka, Larry J; Savory, John

2011-08-01

This review was written as part of the celebration of the International Year of Chemistry 2011. In this review we provide a chronicle of the history of clinical chemistry, with a focus on North America. We outline major methodological advances and trace the development of professional societies and journals dedicated to clinical chemistry. This review also serves as a guide to reference materials for those interested in the history of clinical chemistry. The various resources available, in sound recordings, videos, moving images, image and document archives, museums, and websites dedicated to diagnostic company timelines, are surveyed. These resources provide a map of how the medical subspecialty of clinical chemistry arrived at its present state. This information will undoubtedly help visionaries to determine in which direction clinical chemistry will move in the future.

Surface chemistry: Key to control and advance myriad technologies

PubMed Central

Yates, John T.; Campbell, Charles T.

2011-01-01

This special issue on surface chemistry is introduced with a brief history of the field, a summary of the importance of surface chemistry in technological applications, a brief overview of some of the most important recent developments in this field, and a look forward to some of its most exciting future directions. This collection of invited articles is intended to provide a snapshot of current developments in the field, exemplify the state of the art in fundamental research in surface chemistry, and highlight some possibilities in the future. Here, we show how those articles fit together in the bigger picture of this field. PMID:21245359

Recent advances in medicinal chemistry of sulfonamides. Rational design as anti-tumoral, anti-bacterial and anti-inflammatory agents.

PubMed

Shah, Syed Shoaib Ahmad; Rivera, Gildardo; Ashfaq, Muhammad

2013-01-01

Now-a-days, cancer is becoming one of the major problems of public health in the world. Pharmacology treatment is a way to increase quality and long life. Predominantly, in last decade sulfonamide derivatives have been described as potential carbonic anhydrase inhibitors. In the present work, we describe recent advances during the last decade in medicinal chemistry of sulfonamides derivatives with some examples of rational design as anti-tumoral, antibacterial and anti-inflammatory agents. We show strategy design, structure-activity relationship, biological activity and advances of new sulfonamide compounds that have more health significance than some clinically used sulfonamides.

Support for chemistry symposia at the 2011 American Association for the Advancement of Science meeting, February 17-21 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charles Casey

2011-08-20

This proposal supported Chemistry Symposia at the 2011 American Association for the Advancement of Science (AAAS) Meeting in Washington, DC February 17-21, 2011. The Chemistry Section of AAAS presented an unusually strong set of symposia for the 2011 AAAS meeting to help celebrate the 2011 International Year of Chemistry. The AAAS meeting provided an unusual opportunity to convey the excitement and importance of chemistry to a very broad audience and allowed access to a large contingent of the scientific press. Excellent suggestions for symposia were received from AAAS Chemistry Fellows and from the chairs of the American Chemical Society Technicalmore » Divisions. The AAAS Chemistry executive committee selected topics that would have wide appeal to scientists, the public, and the press for formal proposals of symposia. The symposia proposals were peer reviewed by AAAS. The Chemistry Section made a strong case to the program selection committee for approval of the chemistry symposia and 6 were approved for the 2011 annual meeting. The titles of the approved symposia were: (1) Powering the Planet: Generation of Clean Fuels from Sunlight and Water, (2) Biological Role and Consequences of Intrinsic Protein Disorder, (3) Chemically Speaking: How Organisms Talk to Each Other, (4) Molecular Self-Assembly and Artificial Molecular Machines, (5) Frontiers in Organic Materials for Information Processing, Energy and Sensors, and (6) Celebrating Marie Curie's 100th Anniversary of Her Nobel Prize in Chemistry. The Chemistry Section of AAAS is provided with funds to support only 1-2 symposia a year. Because of the much greater number of symposia approved in conjunction with observance of the 2011 International Year of Chemistry, additional support was sought from DOE to help support the 30 invited speakers and 8 symposia moderators/organizers. Support for the symposia provided the opportunity to highlight the excitement of current chemical research, to educate the public about

Plasma chemistry as a tool for green chemistry, environmental analysis and waste management.

PubMed

Mollah, M Y; Schennach, R; Patscheider, J; Promreuk, S; Cocke, D L

2000-12-15

The applications of plasma chemistry to environmental problems and to green chemistry are emerging fields that offer unique opportunities for advancement. There has been substantial progress in the application of plasmas to analytical diagnostics and to waste reduction and waste management. This review discusses the chemistry and physics necessary to a basic understanding of plasmas, something that has been missing from recent technical reviews. The current status of plasmas in environmental chemistry is summarized and emerging areas of application for plasmas are delineated. Plasmas are defined and discussed in terms of their properties that make them useful for environmental chemistry. Information is drawn from diverse fields to illustrate the potential applications of plasmas in analysis, materials modifications and hazardous waste treatments.

200 Years of Lithium and 100 Years of Organolithium Chemistry

PubMed Central

2018-01-01

The element lithium has been discovered 200 years ago. Due to its unique properties it has emerged to play a vital role in industry, esp. for energy storage, and lithium‐based products and processes support sustainable technological developments. In addition to the many uses of lithium in its inorganic forms, lithium has a rich organometallic chemistry. The development of organometallic chemistry has been hindered by synthetic problems from the start. When Wilhelm Schlenk developed the basic principles to handle and synthesize air‐ and moisture‐sensitive compounds, the road was open to further developments. After more information was available about the stability and solubility of such compounds, they started to play an essential role in other fields of chemistry as alkyl or aryl transfer reagents. PMID:29540939

An Advanced Analytical Chemistry Experiment Using Gas Chromatography-Mass Spectrometry, MATLAB, and Chemometrics to Predict Biodiesel Blend Percent Composition

ERIC Educational Resources Information Center

Pierce, Karisa M.; Schale, Stephen P.; Le, Trang M.; Larson, Joel C.

2011-01-01

We present a laboratory experiment for an advanced analytical chemistry course where we first focus on the chemometric technique partial least-squares (PLS) analysis applied to one-dimensional (1D) total-ion-current gas chromatography-mass spectrometry (GC-TIC) separations of biodiesel blends. Then, we focus on n-way PLS (n-PLS) applied to…

New Thinking in School Chemistry.

ERIC Educational Resources Information Center

Organisation for Economic Cooperation and Development, Paris (France).

This report contains the text of addresses given at a seminar on the status and development of the teaching of secondary school chemistry held in 1960 by the Organization for European Economic Development (now the Organization for Economic Cooperation and Development). The speakers considered advances in theoretical chemistry since 1900, the…

Hybrid protein-inorganic nanoparticles: From tumor-targeted drug delivery to cancer imaging.

PubMed

Elzoghby, Ahmed O; Hemasa, Ayman L; Freag, May S

2016-12-10

Recently, a great interest has been paid to the development of hybrid protein-inorganic nanoparticles (NPs) for drug delivery and cancer diagnostics in order to combine the merits of both inorganic and protein nanocarriers. This review primarily discusses the most outstanding advances in the applications of the hybrids of naturally-occurring proteins with iron oxide, gadolinium, gold, silica, calcium phosphate NPs, carbon nanotubes, and quantum dots in drug delivery and cancer imaging. Various strategies that have been utilized for the preparation of protein-functionalized inorganic NPs and the mechanisms involved in the drug loading process are discussed. How can the protein functionalization overcome the limitations of colloidal stability, poor dispersibility and toxicity associated with inorganic NPs is also investigated. Moreover, issues relating to the influence of protein hybridization on the cellular uptake, tumor targeting efficiency, systemic circulation, mucosal penetration and skin permeation of inorganic NPs are highlighted. A special emphasis is devoted to the novel approaches utilizing the protein-inorganic nanohybrids in combined cancer therapy, tumor imaging, and theranostic applications as well as stimuli-responsive drug release from the nanohybrids. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis and Characterization of Copper Complexes with a Tridentate Nitrogen-Donor Ligand: An Integrated Research Experiment for Undergraduate Students

ERIC Educational Resources Information Center

Bussey, Katherine A.; Cavalier, Annie R.; Connell, Jennifer R.; Mraz, Margaret E.; Holderread, Ashley S.; Oshin, Kayode D.; Pintauer, Tomislav

2015-01-01

An integrated laboratory experiment applying concepts and techniques developed in organic chemistry, inorganic chemistry, and instrumental analysis is presented for use by students interested in undergraduate research. The experiment incorporates some advanced laboratory practices such as multistep organic synthesis and purification, detailed…

Synthesis, Processing, and Characterization of Inorganic-Organic Hybrid Cross-Linked Silica, Organic Polyimide, and Inorganic Aluminosilicate Aerogels

NASA Technical Reports Server (NTRS)

Nguyen, Baochau N.; Guo, Haiquan N.; McCorkle, Linda S.

2014-01-01

As aerospace applications become ever more demanding, novel insulation materials with lower thermal conductivity, lighter weight and higher use temperature are required to fit the aerospace application needs. Having nanopores and high porosity, aerogels are superior thermal insulators, among other things. The use of silica aerogels in general is quite restricted due to their inherent fragility, hygroscopic nature, and poor mechanical properties, especially in extereme aerospace environments. Our research goal is to develop aerogels with better mechanical and environmental stability for a variety of aeronautic and space applications including space suit insulation for planetary surface missions, insulation for inflatable structures for habitats, inflatable aerodynamic decelerators for entry, descent and landing (EDL) operations, and cryotank insulation for advance space propulsion systems. Different type of aerogels including organic-inorganic polymer reinforced (hybrid) silica-based aerogels, polyimide aerogels and inorganic aluminosilicate aerogels have been developed and examined.

Chemistry Is Dead. Long Live Chemistry!

PubMed

Lavis, Luke D

2017-10-03

Chemistry, once king of fluorescence microscopy, was usurped by the field of fluorescent proteins. The increased demands of modern microscopy techniques on the "photon budget" require better and brighter fluorophores, causing a renewed interest in synthetic dyes. Here, we review the recent advances in biochemistry, protein engineering, and organic synthesis that have allowed a triumphant return of chemical fluorophores to modern biological imaging.

Nanobio interfaces: charge control of enzyme/inorganic interfaces for advanced biocatalysis.

PubMed

Deshapriya, Inoka K; Kumar, Challa V

2013-11-19

Specific approaches to the rational design of nanobio interfaces for enzyme and protein binding to nanomaterials are vital for engineering advanced, functional nanobiomaterials for biocatalysis, sensing, and biomedical applications. This feature article presents an overview of our recent discoveries on structural, functional, and mechanistic details of how enzymes interact with inorganic nanomaterials and how they can be controlled in a systematic manner using α-Zr(IV)phosphate (α-ZrP) as a model system. The interactions of a number of enzymes having a wide array of surface charges, sizes, and functional groups are investigated. Interactions are carefully controlled to screen unfavorable repulsions and enhance favorable interactions for high affinity, structure retention, and activity preservation. In specific cases, catalytic activities and substrate selectivities are improved over those of the pristine enzymes, and two examples of high activity near the boiling point of water have been demonstrated. Isothermal titration calorimetric studies indicated that enzyme binding is coupled to ion sequestration or release to or from the nanobio interface, and binding is controlled in a rational manner. We learned that (1) bound enzyme stabilities are improved by lowering the entropy of the denatured state; (2) maximal loadings are obtained by matching charge footprints of the enzyme and the nanomaterial surface; (3) binding affinities are improved by ion sequestration at the nanobio interface; and (4) maximal enzyme structure retention is obtained by biophilizing the nanobio interface with protein glues. The chemical and physical manipulations of the nanobio interface are significant not only for understanding the complex behaviors of enzymes at biological interfaces but also for desiging better functional nanobiomaterials for a wide variety of practical applications.

Synthesis and evaluation of chromogenic and fluorogenic substrates for high-throughput detection of enzymes that hydrolyze inorganic polyphosphate.

PubMed

Hebbard, Carleigh F F; Wang, Yan; Baker, Catherine J; Morrissey, James H

2014-08-11

Inorganic polyphosphates, linear polymers of orthophosphate, occur naturally throughout biology and have many industrial applications. Their biodegradable nature makes them attractive for a multitude of uses, and it would be important to understand how polyphosphates are turned over enzymatically. Studies of inorganic polyphosphatases are, however, hampered by the lack of high-throughput methods for detecting and quantifying rates of polyphosphate degradation. We now report chromogenic and fluorogenic polyphosphate substrates that permit spectrophotometric monitoring of polyphosphate hydrolysis and allow for high-throughput analyses of both endopolyphosphatase and exopolyphosphatase activities, depending on assay configuration. These substrates contain 4-nitrophenol or 4-methylumbelliferone moieties that are covalently attached to the terminal phosphates of polyphosphate via phosphoester linkages formed during reactions mediated by EDAC (1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide). This report identifies Nudt2 as an inorganic polyphosphatase and also adds to the known coupling chemistry for polyphosphates, permitting facile covalent linkage of alcohols with the terminal phosphates of inorganic polyphosphate.

Chemically Integrated Inorganic-Graphene Two-Dimensional Hybrid Materials for Flexible Energy Storage Devices.

PubMed

Peng, Lele; Zhu, Yue; Li, Hongsen; Yu, Guihua

2016-12-01

State-of-the-art energy storage devices are capable of delivering reasonably high energy density (lithium ion batteries) or high power density (supercapacitors). There is an increasing need for these power sources with not only superior electrochemical performance, but also exceptional flexibility. Graphene has come on to the scene and advancements are being made in integration of various electrochemically active compounds onto graphene or its derivatives so as to utilize their flexibility. Many innovative synthesis techniques have led to novel graphene-based hybrid two-dimensional nanostructures. Here, the chemically integrated inorganic-graphene hybrid two-dimensional materials and their applications for energy storage devices are examined. First, the synthesis and characterization of different kinds of inorganic-graphene hybrid nanostructures are summarized, and then the most relevant applications of inorganic-graphene hybrid materials in flexible energy storage devices are reviewed. The general design rules of using graphene-based hybrid 2D materials for energy storage devices and their current limitations and future potential to advance energy storage technologies are also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The intercalation chemistry of layered iron chalcogenide superconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vivanco, Hector K.; Rodriguez, Efrain E., E-mail: efrain@umd.edu

The iron chalcogenides FeSe and FeS are superconductors composed of two-dimensional sheets held together by van der Waals interactions, which makes them prime candidates for the intercalation of various guest species. We review the intercalation chemistry of FeSe and FeS superconductors and discuss their synthesis, structure, and physical properties. Before we review the latest work in this area, we provide a brief background on the intercalation chemistry of other inorganic materials that exhibit enhanced superconducting properties upon intercalation, which include the transition metal dichalcogenides, fullerenes, and layered cobalt oxides. From past studies of these intercalated superconductors, we discuss the rolemore » of the intercalates in terms of charge doping, structural distortions, and Fermi surface reconstruction. We also briefly review the physical and chemical properties of the host materials—mackinawite-type FeS and β-FeSe. The three types of intercalates for the iron chalcogenides can be placed in three categories: 1.) alkali and alkaline earth cations intercalated through the liquid ammonia technique; 2.) cations intercalated with organic amines such as ethylenediamine; and 3.) layered hydroxides intercalated during hydrothermal conditions. A recurring theme in these studies is the role of the intercalated guest in electron doping the chalcogenide host and in enhancing the two-dimensionality of the electronic structure by spacing the FeSe layers apart. We end this review discussing possible new avenues in the intercalation chemistry of transition metal monochalcogenides, and the promise of these materials as a unique set of new inorganic two-dimensional systems.« less

Safety in the Chemical Laboratory: Is Thioacetamide a Serious Health Hazard in Inorganic Chemistry Laboratories?

ERIC Educational Resources Information Center

Elo, Hannu

1987-01-01

Describes the potential health hazards of using thioacetamide in introductory courses where students are involved in qualitative inorganic analysis. Describes the chemical as possessing carcinogenic, hepatotoxic, and mutagenic properties. Cautions that thioacetamide has caused various biochemical changes in the liver, and recommends limited uses…

Reactivity I: A Foundation-Level Course for Both Majors and Nonmajors in Integrated Organic, Inorganic, and Biochemistry

ERIC Educational Resources Information Center

Schaller, Chris P.; Graham, Kate J.; Johnson, Brian J.; Jones, T. Nicholas; McIntee, Edward J.

2015-01-01

A foundation level course is presented that integrates aspects of organic, inorganic and biochemistry in the context of reactivity. The course was designed to serve majors in chemistry and other sciences (biochemistry, biology, nutrition), as well as nursing and pre-health professions students. Themes of the course were designed to highlight a…

Science Update: Analytical Chemistry.

ERIC Educational Resources Information Center

Worthy, Ward

1980-01-01

Briefly discusses new instrumentation in the field of analytical chemistry. Advances in liquid chromatography, photoacoustic spectroscopy, the use of lasers, and mass spectrometry are also discussed. (CS)

Hybrid Organic/Inorganic Materials Depth Profiling Using Low Energy Cesium Ions

NASA Astrophysics Data System (ADS)

Noël, Céline; Houssiau, Laurent

2016-05-01

The structures developed in organic electronics, such as organic light emitting diodes (OLEDs) or organic photovoltaics (OPVs) devices always involve hybrid interfaces, joining metal or oxide layers with organic layers. No satisfactory method to probe these hybrid interfaces physical chemistry currently exists. One promising way to analyze such interfaces is to use in situ ion beam etching, but this requires ion beams able to depth profile both inorganic and organic layers. Mono- or diatomic ion beams commonly used to depth profile inorganic materials usually perform badly on organics, while cluster ion beams perform excellently on organics but yield poor results when organics and inorganics are mixed. Conversely, low energy Cs+ beams (<500 eV) allow organic and inorganic materials depth profiling with comparable erosion rates. This paper shows a successful depth profiling of a model hybrid system made of metallic (Au, Cr) and organic (tyrosine) layers, sputtered with 500 eV Cs+ ions. Tyrosine layers capped with metallic overlayers are depth profiled easily, with high intensities for the characteristic molecular ions and other specific fragments. Metallic Au or Cr atoms are recoiled into the organic layer where they cause some damage near the hybrid interface as well as changes in the erosion rate. However, these recoil implanted metallic atoms do not appear to severely degrade the depth profile overall quality. This first successful hybrid depth profiling report opens new possibilities for the study of OLEDs, organic solar cells, or other hybrid devices.

Nobel Chemistry in the Laboratory: Synthesis of a Ruthenium Catalyst for Ring-Closing Olefin Metathesis--An Experiment for the Advanced Inorganic or Organic Laboratory

ERIC Educational Resources Information Center

Greco, George E.

2007-01-01

An experiment for the upper-level undergraduate laboratory is described in which students synthesize a ruthenium olefin metathesis catalyst, then use the catalyst to carry out the ring-closing metathesis of diethyl diallylmalonate. The olefin metathesis reaction was the subject of the 2005 Nobel Prize in chemistry. The catalyst chosen for this…

Comparing Recent Organizing Templates for Test Content between ACS Exams in General Chemistry and AP Chemistry

ERIC Educational Resources Information Center

Holme, Thomas

2014-01-01

Two different versions of "big ideas" rooted content maps have recently been published for general chemistry. As embodied in the content outline from the College Board, one of these maps is designed to guide curriculum development and testing for advanced placement (AP) chemistry. The Anchoring Concepts Content Map for general chemistry…

Regional Impacts of extending inorganic and organic cloud chemistry with AQCHEM-KMT

EPA Science Inventory

Starting with CMAQ version 5.1, AQCHEM-KMT has been offered as a readily expandable option for cloud chemistry via application of the Kinetic PreProcessor (KPP). AQCHEM-KMT treats kinetic mass transfer between the gas and aqueous phases, ionization, chemical kinetics, droplet sc...

Advances in bionanomaterials for bone tissue engineering.

PubMed

Scott, Timothy G; Blackburn, Gary; Ashley, Michael; Bayer, Ilker S; Ghosh, Anindya; Biris, Alexandru S; Biswas, Abhijit

2013-01-01

Bone is a specialized form of connective tissue that forms the skeleton of the body and is built at the nano and microscale levels as a multi-component composite material consisting of a hard inorganic phase (minerals) in an elastic, dense organic network. Mimicking bone structure and its properties present an important frontier in the fields of nanotechnology, materials science and bone tissue engineering, given the complex morphology of this tissue. There has been a growing interest in developing artificial bone-mimetic nanomaterials with controllable mineral content, nanostructure, chemistry for bone, cartilage tissue engineering and substitutes. This review describes recent advances in bionanomaterials for bone tissue engineering including developments in soft tissue engineering. The significance and basic process of bone tissue engineering along with different bionanomaterial bone scaffolds made of nanocomposites and nanostructured biopolymers/bioceramics and the prerequisite biomechanical functions are described. It also covers latest developments in soft-tissue reconstruction and replacement. Finally, perspectives on the future direction in nanotechnology-enabled bone tissue engineering are presented.

Roles of surface chemistry on safety and electrochemistry in lithium ion batteries.

PubMed

Lee, Kyu Tae; Jeong, Sookyung; Cho, Jaephil

2013-05-21

Motivated by new applications including electric vehicles and the smart grid, interest in advanced lithium ion batteries has increased significantly over the past decade. Therefore, research in this field has intensified to produce safer devices with better electrochemical performance. Most research has focused on the development of new electrode materials through the optimization of bulk properties such as crystal structure, ionic diffusivity, and electric conductivity. More recently, researchers have also considered the surface properties of electrodes as critical factors for optimizing performance. In particular, the electrolyte decomposition at the electrode surface relates to both a lithium ion battery's electrochemical performance and safety. In this Account, we give an overview of the major developments in the area of surface chemistry for lithium ion batteries. These ideas will provide the basis for the design of advanced electrode materials. Initially, we present a brief background to lithium ion batteries such as major chemical components and reactions that occur in lithium ion batteries. Then, we highlight the role of surface chemistry in the safety of lithium ion batteries. We examine the thermal stability of cathode materials: For example, we discuss the oxygen generation from cathode materials and describe how cells can swell and heat up in response to specific conditions. We also demonstrate how coating the surfaces of electrodes can improve safety. The surface chemistry can also affect the electrochemistry of lithium ion batteries. The surface coating strategy improved the energy density and cycle performance for layered LiCoO2, xLi2MnO3·(1 - x)LiMO2 (M = Mn, Ni, Co, and their combinations), and LiMn2O4 spinel materials, and we describe a working mechanism for these enhancements. Although coating the surfaces of cathodes with inorganic materials such as metal oxides and phosphates improves the electrochemical performance and safety properties of

Survey of inorganic polymers. [for composite matrix resins

NASA Technical Reports Server (NTRS)

Gerber, A. H.; Mcinerney, E. F.

1979-01-01

A literature search was carried out in order to identify inorganic, metallo-organic, and hybrid inorganic-organic polymers that could serve as potential matrix resins for advanced composites. The five most promising candidates were critically reviewed and recommendations were made for the achievement of their potential in terms of performance and cost. These generic polymer classes comprise: (1) Poly(arylsil sesquioxanes); (2) Poly(silyl arylene siloxanes); (3) Poly(silarylenes); (4) Poly(silicon-linked ferrocenes); and (5) Poly(organo phosphazenes). No single candidate currently possesses the necessary combination of physicomechanical properties, thermal stability, processability, and favorable economics. The first three classes exhibit the best thermal performance. On the other hand, poly (organo phosphazenes), the most extensively studied polymer class, exhibit the best combination of structure-property control, processability, and favorable economics.

Green Chemistry: Progress and Barriers

NASA Astrophysics Data System (ADS)

Green, Sarah A.

2016-10-01

Green chemistry can advance both the health of the environment and the primary objectives of the chemical enterprise: to understand the behavior of chemical substances and to use that knowledge to make useful substances. We expect chemical research and manufacturing to be done in a manner that preserves the health and safety of workers; green chemistry extends that expectation to encompass the health and safety of the planet. While green chemistry may currently be treated as an independent branch of research, it should, like safety, eventually become integral to all chemistry activities. While enormous progress has been made in shifting from "brown" to green chemistry, much more effort is needed to effect a sustainable economy. Implementation of new, greener paradigms in chemistry is slow because of lack of knowledge, ends-justify-the-means thinking, systems inertia, and lack of financial or policy incentives.

Self-assembly of inorganic nanoparticles: Ab ovo

NASA Astrophysics Data System (ADS)

Kotov, Nicholas A.

2017-09-01

There are numerous remarkable studies related to the self-organization of polymers, coordination compounds, microscale particles, biomolecules, macroscale particles, surfactants, and reactive molecules on surfaces. The focus of this paper is on the self-organization of nanoscale inorganic particles or simply nanoparticles (NPs). Although there are fascinating and profound discoveries made with other self-assembling structures, the ones involving NPs deserve particular attention because they (a) are omnipresent in Nature; (b) have relevance to numerous disciplines (physics, chemistry, biology, astronomy, Earth sciences, and others); (c) embrace most of the features, geometries, and intricacies observed for the self-organization of other chemical species; (d) offer new tools for studies of self-organization phenomena; and (e) have a large economic impact, extending from energy and construction industries, to optoelectronics, biomedical technologies, and food safety. Despite the overall success of the field it is necessary to step back from its multiple ongoing research venues and consider two questions: What is self-assembly of nanoparticles? and Why do we need to study it? The reason to bring them up is to achieve greater scientific depth in the understanding of these omnipresent phenomena and, perhaps, deepen their multifaceted impact. Contribution to the Focus Issue Self-assemblies of Inorganic and Organic Nanomaterials edited by Marie-Paule Pileni.

Frontiers in Chemistry.

ERIC Educational Resources Information Center

Joyce, Robert M., Ed.

1980-01-01

This article describes recent progress in chemical synthesis which depends on comparable advances in other areas of chemistry. Analysis and theories of chemical structure and reactions are determinants in progress in chemical synthesis and are described also. (Author/SA)

Nuclear Chemistry, Science (Experimental): 5316.62.

ERIC Educational Resources Information Center

Williams, Russell R.

This nuclear chemistry module includes topics on atomic structure, instability of the nucleus, detection strengths and the uses of radioactive particles. Laboratory work stresses proper use of equipment and safe handling of radioactive materials. Students with a strong mathematics background may consider this course as advanced work in chemistry.…

Free Radical Addition Polymerization Kinetics without Steady-State Approximations: A Numerical Analysis for the Polymer, Physical, or Advanced Organic Chemistry Course

ERIC Educational Resources Information Center

Iler, H. Darrell; Brown, Amber; Landis, Amanda; Schimke, Greg; Peters, George

2014-01-01

A numerical analysis of the free radical addition polymerization system is described that provides those teaching polymer, physical, or advanced organic chemistry courses the opportunity to introduce students to numerical methods in the context of a simple but mathematically stiff chemical kinetic system. Numerical analysis can lead students to an…

Inorganic SnIP-Type Double Helices in Main-Group Chemistry.

PubMed

Baumgartner, Maximilian; Weihrich, Richard; Nilges, Tom

2017-05-05

Inspired by the synthesis of the first atomic-scale double-helix semiconductor SnIP, this study deals with the question of whether more atomistic, inorganic double-helix compounds are accessible. With the aid of quantum chemical calculations, we have identified 31 candidates by a homoatomic substitution in MXPn, varying the Group 14 M-element from Si to Pb, the Group 17 X-element from F to I and replacing the pnictide (Pn) phosphorus by arsenic. The double-helical structure of SnIP has been used as the starting model for all candidates and the electronic structure and vibrational spectra were determined within the framework of density functional theory (DFT). Varying the outer MX or the inner Pn helix led to the conclusion that iodide- and bromide-containing MXPn compounds show similar structures to SnIP. Here, the calculations indicate interesting effects for electronic band-gap tuning. For the highly polarized fluorides, a segregation of the helices to more complex MX substructures is predicted. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigating hygroscopic behavior and phase separation of organic/inorganic mixed phase aerosol particles with FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Zawadowicz, M. A.; Cziczo, D. J.

2013-12-01

Atmospheric aerosol particles can be composed of inorganic salts, such as ammonium sulfate and sodium chloride, and therefore exhibit hygroscopic properties. Many inorganic salts have very well-defined deliquescence and efflorescence points at which they take up and lose water, respectively. For example, the deliquescence relative humidity of pure ammonium sulfate is about 80% and its efflorescence point is about 35%. This behavior of ammonium sulfate is important to atmospheric chemistry because some reactions, such as the hydrolysis of nitrogen pentoxide, occur on aqueous but not crystalline surfaces. Deliquescence and efflorescence of simple inorganic salt particles have been investigated by a variety of methods, such as IR spectroscopy, tandem mobility analysis and electrodynamic balance. Field measurements have shown that atmospheric aerosol are not typically a single inorganic salt, instead they often contain organic as well as inorganic species. Mixed inorganic/organic aerosol particles, while abundant in the atmosphere, have not been studied as extensively. Many recent studies have focused on microscopy techniques that require deposition of the aerosol on a glass slide, possibly changing its surface properties. This project investigates the deliquescence and efflorescence points, phase separation and ability to exchange gas-phase components of mixed organic and inorganic aerosol using a flow tube coupled with FTIR spectroscopy. Ammonium sulfate aerosol mixed with organic polyols with different O:C ratios, including glycerol, 1,2,6-hexanetriol, 1,4-butanediol and 1,5-pentanediol have been investigated. This project aims to study gas-phase exchange in these aerosol systems to determine if exchange is impacted when phase separation occurs.

Synthesis and Self-Assembly of the "Tennis Ball" Dimer and Subsequent Encapsulation of Methane. An Advanced Organic Chemistry Laboratory Experiment

NASA Astrophysics Data System (ADS)

Hof, Fraser; Palmer, Liam C.; Rebek, Julius, Jr.

2001-11-01

While important to the biological and materials sciences, noncovalent interactions, self-folding, and self-assembly often receive little discussion in the undergraduate chemistry curriculum. The synthesis and NMR characterization of a molecular "tennis ball" in an advanced undergraduate organic chemistry laboratory is a simple and effective way to introduce the relevance of these concepts. In appropriate solvents, the monomer dimerizes through a seam of eight hydrogen bonds with encapsulation of a guest molecule and symmetry reminiscent of a tennis ball. The entire experiment can be completed in three lab periods, however large-scale synthetic preparation of the starting monomer by a teaching assistant would reduce the laboratory to a single lab period for NMR studies.

Computation of Phase Equilibria, State Diagrams and Gas/Particle Partitioning of Mixed Organic-Inorganic Aerosols

NASA Astrophysics Data System (ADS)

Zuend, A.; Marcolli, C.; Peter, T.

2009-04-01

The chemical composition of organic-inorganic aerosols is linked to several processes and specific topics in the field of atmospheric aerosol science. Photochemical oxidation of organics in the gas phase lowers the volatility of semi-volatile compounds and contributes to the particulate matter by gas/particle partitioning. Heterogeneous chemistry and changes in the ambient relative humidity influence the aerosol composition as well. Molecular interactions between condensed phase species show typically non-ideal thermodynamic behavior. Liquid-liquid phase separations into a mainly polar, aqueous and a less polar, organic phase may considerably influence the gas/particle partitioning of semi-volatile organics and inorganics (Erdakos and Pankow, 2004; Chang and Pankow, 2006). Moreover, the phases present in the aerosol particles feed back on the heterogeneous, multi-phase chemistry, influence the scattering and absorption of radiation and affect the CCN ability of the particles. Non-ideal thermodynamic behavior in mixtures is usually described by an expression for the excess Gibbs energy, enabling the calculation of activity coefficients. We use the group-contribution model AIOMFAC (Zuend et al., 2008) to calculate activity coefficients, chemical potentials and the total Gibbs energy of mixed organic-inorganic systems. This thermodynamic model was combined with a robust global optimization module to compute potential liquid-liquid (LLE) and vapor-liquid-liquid equilibria (VLLE) as a function of particle composition at room temperature. And related to that, the gas/particle partitioning of semi-volatile components. Furthermore, we compute the thermodynamic stability (spinodal limits) of single-phase solutions, which provides information on the process type and kinetics of a phase separation. References Chang, E. I. and Pankow, J. F.: Prediction of activity coefficients in liquid aerosol particles containing organic compounds, dissolved inorganic salts, and water - Part

Laboratory investigation of inorganic carbon uptake by cryoconite debris from Werenskioldbreen, Svalbard

NASA Astrophysics Data System (ADS)

Stibal, Marek; Tranter, Martyn

2007-12-01

Laboratory experiments were undertaken to determine the inorganic carbon uptake rate and the interactions between photosynthesis and water chemistry, particularly pH and nutrient concentrations, for cryoconite debris from Werenskioldbreen, a well-researched Svalbard glacier. Microorganisms in cryoconite debris took up inorganic carbon at rates between 0.6 and 15 μg C L-1 h-1 and fixed it as organic carbon. Cyanobacterial photosynthesis (75-93%) was the main process responsible for inorganic carbon fixation, while heterotrophic uptake (6-15%) only accounted for a minor part. The microbes in cryoconite debris were active shortly after melt and fixed carbon as long as there were favorable conditions. They were not truly psychrophilic: their physiological optimum temperature was higher than is prevalent in cryoconite holes. The pH was also a factor affecting photosynthesis in the cryoconite slurry. The highest dissolved inorganic carbon (DIC) uptake rates per liter of slurry occurred at pH ˜7, and there was a significant correlation between the initial pH and DIC fixation on a per cell basis, showing increasing DIC uptake rates when pH increased from ˜5.5 to 9. Inorganic carbon fixation resulted in an increased pH in solution. However, the microbes were able to photosynthesize in a wide range of pH from ˜4 to ˜10. The average C:N:P molar ratios in solution were ˜350:75:1. Unlike nitrogen, phosphorus concentrations decreased with increasing carbon uptake, and when the rate approached ˜15 μg C L-1 h-1, all available dissolved phosphorus was utilized within 6 h. Hence phosphorus is probably biolimiting in this system.

Integrating Particulate Representations into AP Chemistry and Introductory Chemistry Courses

ERIC Educational Resources Information Center

Prilliman, Stephen G.

2014-01-01

The College Board's recently revised curriculum for advanced placement (AP) chemistry places a strong emphasis on conceptual understanding, including representations of particle phenomena. This change in emphasis is informed by years of research showing that students could perform algorithmic calculations but not explain those calculations…

Recent advances in research applications of nanophase hydroxyapatite.

PubMed

Fox, Kate; Tran, Phong A; Tran, Nhiem

2012-07-16

Hydroxyapatite, the main inorganic material in natural bone, has been used widely for orthopaedic applications. Due to size effects and surface phenomena at the nanoscale, nanophase hydroxyapatite possesses unique properties compared to its bulk-phase counterpart. The high surface-to-volume ratio, reactivities, and biomimetic morphologies make nano-hydroxyapatite more favourable in applications such as orthopaedic implant coating or bone substitute filler. Recently, more efforts have been focused on the possibility of combining hydroxyapatite with other drugs and materials for multipurpose applications, such as antimicrobial treatments, osteoporosis treatments and magnetic manipulation. To build more effective nano-hydroxyapatite and composite systems, the particle synthesis processes, chemistry, and toxicity have to be thoroughly investigated. In this Minireview, we report the recent advances in research regarding nano-hydroxyapatite. Synthesis routes and a wide range of applications of hydroxyapatite nanoparticles will be discussed. The Minireview also addresses several challenges concerning the biosafety of the nanoparticles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low temperature surface chemistry and nanostructures

NASA Astrophysics Data System (ADS)

Sergeev, G. B.; Shabatina, T. I.

2002-03-01

The new scientific field of low temperature surface chemistry, which combines the low temperature chemistry (cryochemistry) and surface chemistry approaches, is reviewed in this paper. One of the most exciting achievements in this field of science is the development of methods to create highly ordered hybrid nanosized structures on different organic and inorganic surfaces and to encapsulate nanosized metal particles in organic and polymer matrices. We consider physical and chemical behaviour for the systems obtained by co-condensation of the components vapours on the surfaces cooled down to 4-10 and 70-100 K. In particular the size effect of both types, the number of atoms in the reactive species structure and the thickness of growing co-condensate film, on the chemical activity of the system is analysed in detail. The effect of the internal mechanical stresses on the growing interfacial co-condensate film formation and on the generation of fast (explosive) spontaneous reactions at low temperatures is discussed. The examples of unusual chemical interactions of metal atoms, clusters and nanosized particles, obtained in co-condensate films on the cooled surfaces under different conditions, are presented. The examples of highly ordered surface and volume hybrid nanostructures formation are analysed.

Using Oral Examination as a Technique to Assess Student Understanding and Teaching Effectiveness

ERIC Educational Resources Information Center

Roecker, Lee

2007-01-01

This paper discusses the use of oral examinations to assess student understanding in a general chemistry course and in an advanced inorganic chemistry course. Examination design, administration, and grading are explored, as well as the benefits to both instructors and students. Students react positively to the oral examination format and generally…

Extraterrestrial Radiation Chemistry and Molecular Astronomy

NASA Technical Reports Server (NTRS)

Hudson, Reggie L.; Moore, Marla H.

2009-01-01

Astronomical observations of both solar system and interstellar regions have revealed a rich chemical inventory that includes most classes of organic molecules and selected inorganics. For example, gas-phase ethylene glycol and SOz have been observed by astronomers, while solidphase detections include OCS, H2O2 , and the cyanate anion.' All of these are found in environments that are, by earthly standards, exceedingly hostile: temperatures of 10 - 100 K, miniscule densities, and near-ubiquitous ionizing-radiation fields. Beyond the simplest chemical species, these conditions have made it difficult-to-impassible to account for the observed molecular abundances using gas-phase chemistry, suggesting solid-phase reactions play an important role. In extraterrestrial environments, cosmic rays, UV photons, and magnetospheric radiation all drive chemical reactions, even at cryogenic temperatures. To study this chemistry, radiation astrochemists conduct experiments on icy materials, frozen under vacuum and exposed to sources such as keV electrons and MeV protons. Compositional changes usually are followed with IR spectroscopy and, in selected cases, more-sensitive mass-spectral techniques. This talk will review some recent results on known and suspected extraterrestrial molecules and ions. Spectra and reaction pathways will be presented, and predictions made for interstellar chemistry and the chemistry of selected solar system objects. Some past radiation-chemical contributions, and future needs, will be explored.

Solventless and One-Pot Synthesis of Cu(II) Phthalocyanine Complex: A Green Chemistry Experiment

ERIC Educational Resources Information Center

Sharma, R. K.; Sharma, Chetna; Sidhwani, Indu Tucker

2011-01-01

With the growing awareness of green chemistry, it is increasingly important for students to understand this concept in the context of laboratory experiments. Although microwave-assisted organic synthesis has become a common and invaluable technique in recent years, there have been few procedures published for microwave-assisted inorganic synthesis…

Bioorthogonal chemistry: applications in activity-based protein profiling.

PubMed

Willems, Lianne I; van der Linden, Wouter A; Li, Nan; Li, Kah-Yee; Liu, Nora; Hoogendoorn, Sascha; van der Marel, Gijs A; Florea, Bogdan I; Overkleeft, Herman S

2011-09-20

The close interaction between organic chemistry and biology goes back to the late 18th century, when the modern natural sciences began to take shape. After synthetic organic chemistry arose as a discipline, organic chemists almost immediately began to pursue the synthesis of naturally occurring compounds, thereby contributing to the understanding of their functions in biological processes. Research in those days was often remarkably interdisciplinary; in fact, it constituted chemical biology research before the phrase even existed. For example, histological dyes, both of an organic and inorganic nature, were developed and applied by independent researchers (Gram and Golgi) with the aim of visualizing cellular substructures (the bacterial cell wall and the Golgi apparatus). Over the years, as knowledge within the various fields of the natural sciences deepened, research disciplines drifted apart, becoming rather monodisciplinary. In these years, broadly ranging from the end of World War II to about the 1980s, organic chemistry continued to impact life sciences research, but contributions were of a more indirect nature. As an example, the development of the polymerase chain reaction, from which molecular biology and genetics research have greatly profited, was partly predicated on the availability of synthetic oligonucleotides. These molecules first became available in the late 1960s, the result of organic chemists pursuing the synthesis of DNA oligomers primarily because of the synthetic challenges involved. Today, academic natural sciences research is again becoming more interdisciplinary, and sometimes even multidisciplinary. What was termed "chemical biology" by Stuart Schreiber at the end of the last century can be roughly described as the use of intellectually chemical approaches to shed light on processes that are fundamentally rooted in biology. Chemical tools and techniques that are developed for biological studies in the exciting and rapidly evolving field

The chemistry of cationic polyphosphorus cages – syntheses, structure and reactivity

PubMed Central

Holthausen, Michael H.

2014-01-01

The aim of this review is to provide a comprehensive view of the chemistry of cationic polyphosphorus cages. The synthetic protocols established for their preparation, which are all based on the functionalization of P4, and their intriguing follow-up chemistry are highlighted. In addition, this review intends to foster the interest of the inorganic, organic, catalytic and material oriented chemical communities in the versatile field of polyphosphorus cage compounds. In the long term, this is envisioned to contribute to the development of new synthetic procedures for the functionalization of P4 and its transformation into (organo-)phosphorus compounds and materials of added value. PMID:24740160

Flow chemistry meets advanced functional materials.

PubMed

Myers, Rebecca M; Fitzpatrick, Daniel E; Turner, Richard M; Ley, Steven V

2014-09-22

Flow chemistry and continuous processing techniques are beginning to have a profound impact on the production of functional materials ranging from quantum dots, nanoparticles and metal organic frameworks to polymers and dyes. These techniques provide robust procedures which not only enable accurate control of the product material's properties but they are also ideally suited to conducting experiments on scale. The modular nature of flow and continuous processing equipment rapidly facilitates reaction optimisation and variation in function of the products. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Advancements of computer chemistry in separation of Chinese medicine].

PubMed

Li, Lingjuan; Hong, Hong; Xu, Xuesong; Guo, Liwei

2011-12-01

Separating technique of Chinese medicine is not only a key technique in the field of Chinese medicine' s research and development, but also a significant step in the modernization of Chinese medicinal preparation. Computer chemistry can build model and look for the regulations from Chinese medicine system which is full of complicated data. This paper analyzed the applicability, key technology, basic mode and common algorithm of computer chemistry applied in the separation of Chinese medicine, introduced the mathematic mode and the setting methods of Extraction kinetics, investigated several problems which based on traditional Chinese medicine membrane procession, and forecasted the application prospect.

Nickel-Catalyzed Suzuki-Miyaura Cross-Coupling in a Green Alcohol Solvent for an Undergraduate Organic Chemistry Laboratory.

PubMed

Hie, Liana; Chang, Jonah J; Garg, Neil K

2015-03-10

A modern undergraduate organic chemistry laboratory experiment involving the Suzuki-Miyaura coupling is reported. Although Suzuki-Miyaura couplings typically employ palladium catalysts in environmentally harmful solvents, this experiment features the use of inexpensive nickel catalysis, in addition to a "green" alcohol solvent. The experiment employs heterocyclic substrates, which are important pharmaceutical building blocks. Thus, this laboratory procedure exposes students to a variety of contemporary topics in organic chemistry, including transition metal-catalyzed cross-couplings, green chemistry, and the importance of heterocycles in drug discovery, none of which are well represented in typical undergraduate organic chemistry curricula. The experimental protocol uses commercially available reagents and is useful in both organic and inorganic instructional laboratories.

Inorganic Reactive Sulfur-Nitrogen Species: Intricate Release Mechanisms or Cacophony in Yellow, Blue and Red?

PubMed Central

Grman, Marian; Nasim, Muhammad Jawad; Leontiev, Roman; Misak, Anton; Jakusova, Veronika; Ondrias, Karol; Jacob, Claus

2017-01-01

Since the heydays of Reactive Sulfur Species (RSS) research during the first decade of the Millennium, numerous sulfur species involved in cellular regulation and signalling have been discovered. Yet despite the general predominance of organic species in organisms, recent years have also seen the emergence of inorganic reactive sulfur species, ranging from inorganic polysulfides (HSx−/Sx2−) to thionitrous acid (HSNO) and nitrosopersulfide (SSNO−). These inorganic species engage in a complex interplay of reactions in vitro and possibly also in vivo. Employing a combination of spectrophotometry and sulfide assays, we have investigated the role of polysulfanes from garlic during the release of nitric oxide (•NO) from S-nitrosoglutathione (GSNO) in the absence and presence of thiol reducing agents. Our studies reveal a distinct enhancement of GSNO decomposition by compounds such as diallyltrisulfane, which is most pronounced in the presence of cysteine and glutathione and presumably proceeds via the initial release of an inorganic mono- or polysulfides, i.e., hydrogen sulfide (H2S) or HSx−, from the organic polysulfane. Albeit being of a preliminary nature, our spectrophotometric data also reveals a complicated underlying mechanism which appears to involve transient species such as SSNO−. Eventually, more in depth studies are required to further explore the underlying chemistry and wider biological and nutritional implications of this interplay between edible garlic compounds, reductive activation, inorganic polysulfides and their interplay with •NO storage and release. PMID:28212297

[Impact of Rocky Desertification Treatment on Underground Water Chemistry and Dissolved Inorganic Carbon Isotope in Karst Areas].

PubMed

Xiao, Shi-zhen; Xiong, Kang-ning; Lan, Jia-cheng; Zhang, Hui; Yang, Long

2015-05-01

Five springs representing different land-use types and different karst rocky desertification treatment models were chosen at the Huajiang Karst Rocky Desertification Treatment Demonstration Site in Guanling-Zhenfeng Counties in Guizhou, to analyze the features of underground water chemistry and dissolved inorganic carbon isotopes (δ13C(DIC)) and reveal the effect of rocky desertification treatment on karstification and water quality. It was found that, the underground water type of the research area was HCO3-Ca; the water quality of the springs which were relatively less affected by human activities including Shuijingwan Spring (SJW) , Gebei Spring (GB), and Maojiawan Spring (MJW) was better than those relatively more affected by human activities including Diaojing Spring (DJ) and Tanjiazhai Spring (TJZ) , the main ion concentrations and electrical conductivity of which were higher; pH, SIc and pCO2 were sensitive to land-use types and rocky desertification treatment, which could be shown by the higher pH and SIc and lower pCO2 in MJW than those in the other four springs; (Ca(2+) + Mg2+)/HCO(3-) of SJW, MJW and GB were nearly 1:1, dominated by carbonate rock weathering by carbon acid, while the (Ca(2+) + Mg2+) of DJ and TJZ was much higher than HCO3-, suggesting that sulfate and nitrate might also dissolve carbonate rock because of the agricultural activities; δ13C(DIC) was lighter in wet season because of the higher biological activities; the average δ13C(DIC) was in the order of DJ (-12.79 per thousand) < SJW (-12.48 per thousand) < GB (-10.76 per thousand)) < MJW (-10.30 per thousand) < TJZ (-6.70 per thousand), which demonstrated that δ13C(DIC) would be heavier after rocky desertification and lighter after the rocky desertification are treated and controlled.

UNESCO Chemistry Teaching Project in Asia, Newsletter, Volume 3, Number 1, August 1969.

ERIC Educational Resources Information Center

United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand).

The "Chemistry Card Game" for teaching stoichiometry of inorganic precipitation and ionic complex reactions is described in the first article of this UNESCO newsletter. The game is played with 106 cards consisting of 19 kinds of cations, 14 kinds of anions, and one kind of molecules (NH3). Included are the instructions for making the…

Mono- and binuclear non-heme iron chemistry from a theoretical perspective.

PubMed

Rokob, Tibor András; Chalupský, Jakub; Bím, Daniel; Andrikopoulos, Prokopis C; Srnec, Martin; Rulíšek, Lubomír

2016-09-01

In this minireview, we provide an account of the current state-of-the-art developments in the area of mono- and binuclear non-heme enzymes (NHFe and NHFe2) and the smaller NHFe(2) synthetic models, mostly from a theoretical and computational perspective. The sheer complexity, and at the same time the beauty, of the NHFe(2) world represents a challenge for experimental as well as theoretical methods. We emphasize that the concerted progress on both theoretical and experimental side is a conditio sine qua non for future understanding, exploration and utilization of the NHFe(2) systems. After briefly discussing the current challenges and advances in the computational methodology, we review the recent spectroscopic and computational studies of NHFe(2) enzymatic and inorganic systems and highlight the correlations between various experimental data (spectroscopic, kinetic, thermodynamic, electrochemical) and computations. Throughout, we attempt to keep in mind the most fascinating and attractive phenomenon in the NHFe(2) chemistry, which is the fact that despite the strong oxidative power of many reactive intermediates, the NHFe(2) enzymes perform catalysis with high selectivity. We conclude with our personal viewpoint and hope that further developments in quantum chemistry and especially in the field of multireference wave function methods are needed to have a solid theoretical basis for the NHFe(2) studies, mostly by providing benchmarking and calibration of the computationally efficient and easy-to-use DFT methods.

Integration of Computational Chemistry into the Undergraduate Organic Chemistry Laboratory Curriculum

ERIC Educational Resources Information Center

Esselman, Brian J.; Hill, Nicholas J.

2016-01-01

Advances in software and hardware have promoted the use of computational chemistry in all branches of chemical research to probe important chemical concepts and to support experimentation. Consequently, it has become imperative that students in the modern undergraduate curriculum become adept at performing simple calculations using computational…

An electrochemical and photophysical study of a covalently linked inorganic-organic dyad.

PubMed

Kahnt, Axel; Heiniger, Leo-Philipp; Liu, Shi-Xia; Tu, Xiaoyan; Zheng, Zhiping; Hauser, Andreas; Decurtins, Silvio; Guldi, Dirk M

2010-02-22

A molecular donor-acceptor dyad comprising a hexarhenium cluster core, [Re(6)(mu(3)-Se)(8)](2+), and a fullerene moiety which are covalently linked through a pyridine ligand was synthesized and fully characterized. The electrochemical and photophysical properties are reported. The detailed study includes cyclic voltammetry, steady-state absorption and fluorescence spectroscopy, radiation chemistry and transient absorption spectroscopy. A light-induced electron transfer between the inorganic cluster moiety and the fullerene can be excluded. However, a light-induced energy transfer from the rhenium cluster to the fullerene is proposed.

Thermal Behavior of d-Ribose Adsorbed on Silica: Effect of Inorganic Salt Coadsorption and Significance for Prebiotic Chemistry.

PubMed

Akouche, Mariame; Jaber, Maguy; Zins, Emilie-Laure; Maurel, Marie-Christine; Lambert, Jean-Francois; Georgelin, Thomas

2016-10-24

Understanding ribose reactivity is a crucial step in the "RNA world" scenario because this molecule is a component of all extant nucleotides that make up RNA. In solution, ribose is unstable and susceptible to thermal destruction. We examined how ribose behaves upon thermal activation when adsorbed on silica, either alone or with the coadsorption of inorganic salts (MgCl 2 , CaCl 2 , SrCl 2 , CuCl 2 , FeCl 2 , FeCl 3 , ZnCl 2 ). A combination of 13 C NMR, in situ IR, and TGA analyses revealed a variety of phenomena. When adsorbed alone, ribose remains stable up to 150 °C, at which point ring opening is observed, together with minor oxidation to a lactone. All the metal salts studied showed specific interactions with ribose after dehydration, resulting in the formation of polydentate metal ion complexes. Anomeric equilibria were affected, generally favoring ribofuranoses. Zn 2+ stabilized ribose up to higher temperatures than bare silica (180 to 200 °C). Most other cations had an adverse effect on ribose stability, with ring opening already upon drying at 70 °C. In addition, alkaline earth cations catalyzed the dehydration of ribose to furfural and, to variable degrees, its further decarbonylation to furan. Transition-metal ions with open d-shells took part in redox reactions with ribose, either as reagents or as catalysts. These results allow the likelihood of prebiotic chemistry scenarios to be evaluated, and may also be of interest for the valorization of biomass-derived carbohydrates by heterogeneous catalysis. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Continuous Symmetry and Chemistry Teachers: Learning Advanced Chemistry Content through Novel Visualization Tools

ERIC Educational Resources Information Center

Tuvi-Arad, Inbal; Blonder, Ron

2010-01-01

In this paper we describe the learning process of a group of experienced chemistry teachers in a specially designed workshop on molecular symmetry and continuous symmetry. The workshop was based on interactive visualization tools that allow molecules and their symmetry elements to be rotated in three dimensions. The topic of continuous symmetry is…

Properties, performance and associated hazards of state-of-the-art durable water repellent (DWR) chemistry for textile finishing.

PubMed

Holmquist, H; Schellenberger, S; van der Veen, I; Peters, G M; Leonards, P E G; Cousins, I T

2016-05-01

Following the phase-out of long-chain per- and polyfluoroalkyl substances (PFASs), the textile industry had to find alternatives for side-chain fluorinated polymer based durable water repellent (DWR) chemistries that incorporated long perfluoroalkyl side chains. This phase-out and subsequent substitution with alternatives has resulted in a market where both fluorinated and non-fluorinated DWRs are available. These DWR alternatives can be divided into four broad groups that reflect their basic chemistry: side-chain fluorinated polymers, silicones, hydrocarbons and other chemistries (includes dendrimer and inorganic nanoparticle chemistries). In this critical review, the alternative DWRs are assessed with regards to their structural properties and connected performance, loss and degradation processes resulting in diffuse environmental emissions, and hazard profiles for selected emitted substances. Our review shows that there are large differences in performance between the alternative DWRs, most importantly the lack of oil repellence of non-fluorinated alternatives. It also shows that for all alternatives, impurities and/or degradation products of the DWR chemistries are diffusively emitted to the environment. Our hazard ranking suggests that hydrocarbon based DWR is the most environmentally benign, followed by silicone and side-chain fluorinated polymer-based DWR chemistries. Industrial commitments to reduce the levels of impurities in silicone based and side-chain fluorinated polymer based DWR formulations will lower the actual risks. There is a lack of information on the hazards associated with DWRs, in particular for the dendrimer and inorganic nanoparticle chemistries, and these data gaps must be filled. Until environmentally safe alternatives, which provide the required performance, are available our recommendation is to choose DWR chemistry on a case-by-case basis, always weighing the benefits connected to increased performance against the risks to the

Inorganic-Organic Polymers and Their Role in Materials Science

DTIC Science & Technology

1994-05-18

North Quincy Street AD-A279 715 Arlington, Virginia 22217-5000 H IM 11. SUPPLEMENTARY NOTES Prepared for publication in ADVAtICED MlATERIALS 12a...This document has been approved for public release; distribution is unlimited. 13. ABSTRACT (Maximum 200 words) The design and synthesis of new...Technical Report No. 19 INORGANIC-ORGANIC POLYMERS AND THEIR ROLE IN MATERIALS SCIENCE by Harry R. Allcock Prepared for Publication in Advanced Materials

Per-Olov Löwdin - father of quantum chemistry

NASA Astrophysics Data System (ADS)

Brändas, Erkki J.

2017-09-01

During 2016, we celebrate the 100th anniversary of the birth of Per-Olov Löwdin. He was appointed to the first Lehrstuhl in quantum chemistry at Uppsala University in 1960. Löwdin introduced quantum chemistry as a field in its own right by formulating its goals, establishing fundamental concepts, like the correlation energy, the method of configuration interaction, reduced density matrices, natural spin orbitals, charge and bond order matrices, symmetric orthogonalisation, and generalised self-consistent fields. His exposition of partitioning technique and perturbation theory, wave and reaction operators and associated non-linear summation techniques, introduced mathematical rigour and deductive order in the interpretative organisation of the new field. He brought the first computer to Uppsala University and pioneered the initiation of 'electronic brains' and anticipated their significance for quantum chemistry. Perhaps his single most influential contribution to the field was his education of two generations of future faculty in quantum chemistry through Summer Schools in the Scandinavian Mountains, Winter Institutes at Sanibel Island in the Gulf of Mexico. Per-Olov Löwdin founded the book series Advances in Quantum Chemistry and the International Journal of Quantum Chemistry. The evolution of quantum chemistry is appraised, starting from a collection of cross-disciplinary applications of quantum mechanics to the technologically advanced and predominant field of today, virtually used in all branches of chemistry. The scientific work of Per-Olov Löwdin has been crucial for the development of this new important province of science.

Semiconducting Organic-Inorganic Nanodots Heterojunctions: Platforms for General Photoelectrochemical Bioanalysis Application.

PubMed

Wang, Qian; Ruan, Yi-Fan; Zhao, Wei-Wei; Lin, Peng; Xu, Jing-Juan; Chen, Hong-Yuan

2018-03-20

In this study, semiconducting organic polymer dots (Pdots) and inorganic quantum dots (Qdots) were first utilized to construct the organic-inorganic nanodots heterojunction for the photoelectrochemical (PEC) bioanalysis application. Specifically, n-type CdS Qdots, p-type CdTe Qdots, and tetraphenylporphyrin (TPP)-doped poly[(9,9-dioctylfluorenyl-2,7-diyl)- co-(1,4-benzo-{2,1',3}-thiadazole)] (PFBT) Pdots were fabricated, and their energy levels, that is, their valence band (VB)/conduction band (CB) or lowest unoccupied molecular orbital (LUMO)/highest occupied molecular orbital (HOMO) values, were also determined. Then, these nanodots were integrated to construct four types of p-n and p-p organic-inorganic nanodots heterojunctions, that is, CdS Qdots/TPP-doped PFBT Pdots, TPP-doped PFBT Pdots/CdS Qdots, CdTe Qdots/TPP-doped PFBT Pdots, and TPP-doped PFBT Pdots/CdTe Qdots, on the transparent glass electrode. Upon light irradiation, four heterojunctions exhibited different PEC behaviors with some having prominent photocurrent enhancement. With the model molecule l-cysteine (l-cys) as target, the proposed PEC sensor exhibited good performances. In brief, this work presents the first semiconducting organic-inorganic nanodots heterojunction for PEC bioanalysis application, which could be easily used as a general platform for future PEC bioanalysis building. Besides, it is expected to inspire more interest in the design, development, and implementation of various organic-inorganic heterojunctions for advanced PEC bioanalysis in the future.

Recent Advances in Inorganic Nanoparticle-Based NIR Luminescence Imaging: Semiconductor Nanoparticles and Lanthanide Nanoparticles.

PubMed

Kim, Dokyoon; Lee, Nohyun; Park, Yong Il; Hyeon, Taeghwan

2017-01-18

Several types of nanoparticle-based imaging probes have been developed to replace conventional luminescent probes. For luminescence imaging, near-infrared (NIR) probes are useful in that they allow deep tissue penetration and high spatial resolution as a result of reduced light absorption/scattering and negligible autofluorescence in biological media. They rely on either an anti-Stokes or a Stokes shift process to generate luminescence. For example, transition metal-doped semiconductor nanoparticles and lanthanide-doped inorganic nanoparticles have been demonstrated as anti-Stokes shift-based agents that absorb NIR light through two- or three-photon absorption process and upconversion process, respectively. On the other hand, quantum dots (QDs) and lanthanide-doped nanoparticles that emit in NIR-II range (∼1000 to ∼1350 nm) were suggested as promising Stokes shift-based imaging agents. In this topical review, we summarize and discuss the recent progress in the development of inorganic nanoparticle-based luminescence imaging probes working in NIR range.

PhET Interactive Simulations: Transformative Tools for Teaching Chemistry

ERIC Educational Resources Information Center

Moore, Emily B.; Chamberlain, Julia M.; Parson, Robert; Perkins, Katherine K.

2014-01-01

Developing fluency across symbolic-, macroscopic-, and particulate-level representations is central to learning chemistry. Within the chemistry education community, animations and simulations that support multi-representational fluency are considered critical. With advances in the accessibility and sophistication of technology,…

Integrating Project-Based Service-Learning into an Advanced Environmental Chemistry Course

NASA Astrophysics Data System (ADS)

Draper, Alison J.

2004-02-01

In an advanced environmental chemistry course, the inclusion of semester-long scientific service projects successfully integrated the research process with course content. Each project involved a unique community-based environmental analysis in which students assessed an aspect of environmental health. The projects were due in small pieces at even intervals, and students worked independently or in pairs. Initially, students wrote a project proposal in which they chose and justified a project. Following a literature review of their topic, they drafted sampling and analysis plans using methods in the literature. Samples were collected and analyzed, and all students assembled scientific posters describing the results of their study. In the last week of the semester, the class traveled to a regional professional meeting to present the posters. In all, students found the experience valuable. They learned to be professional environmental chemists and learned the value of the discipline to community health. Students not only learned about their own project in depth, but they were inspired to learn textbook material, not for an exam, but because it helped them understand their own project. Finally, having a community to answer to at the end of the project motivated students to do careful work.

Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry

PubMed Central

Küpper, Frithjof C.; Carpenter, Lucy J.; McFiggans, Gordon B.; Palmer, Carl J.; Waite, Tim J.; Boneberg, Eva-Maria; Woitsch, Sonja; Weiller, Markus; Abela, Rafael; Grolimund, Daniel; Potin, Philippe; Butler, Alison; Luther, George W.; Kroneck, Peter M. H.; Meyer-Klaucke, Wolfram; Feiters, Martin C.

2008-01-01

Brown algae of the Laminariales (kelps) are the strongest accumulators of iodine among living organisms. They represent a major pump in the global biogeochemical cycle of iodine and, in particular, the major source of iodocarbons in the coastal atmosphere. Nevertheless, the chemical state and biological significance of accumulated iodine have remained unknown to this date. Using x-ray absorption spectroscopy, we show that the accumulated form is iodide, which readily scavenges a variety of reactive oxygen species (ROS). We propose here that its biological role is that of an inorganic antioxidant, the first to be described in a living system. Upon oxidative stress, iodide is effluxed. On the thallus surface and in the apoplast, iodide detoxifies both aqueous oxidants and ozone, the latter resulting in the release of high levels of molecular iodine and the consequent formation of hygroscopic iodine oxides leading to particles, which are precursors to cloud condensation nuclei. In a complementary set of experiments using a heterologous system, iodide was found to effectively scavenge ROS in human blood cells. PMID:18458346

Inorganic Polymers.

DTIC Science & Technology

1987-07-16

inorganic plastics since the siloxanes . They have great potential and may in time prove to be even more useful than the polysiloxanes since many of these...important new class of seni-inorganic plastics since the siloxanes . They have great potential and may in time prove to be even more useful than the... biomedical qualities and useful engineering material parameters, toxicological, corrosion and fire resistance characteristics place many of the

ANALYTICAL CHEMISTRY DIVISION ANNUAL PROGRESS REPORT FOR PERIOD ENDING DECEMBER 31, 1961

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1962-02-01

Research and development progress is reported on analytlcal instrumentation, dlssolver-solution analyses, special research problems, reactor projects analyses, x-ray and spectrochemical analyses, mass spectrometry, optical and electron microscopy, radiochemical analyses, nuclear analyses, inorganic preparations, organic preparations, ionic analyses, infrared spectral studies, anodization of sector coils for the Analog II Cyclotron, quality control, process analyses, and the Thermal Breeder Reactor Projects Analytical Chemistry Laboratory. (M.C.G.)

A Test of Strategies for Enhanced Learning of AP Descriptive Chemistry

ERIC Educational Resources Information Center

Kotcherlakota, Suhasini; Brooks, David W.

2008-01-01

The Advanced Placement (AP) Descriptive Chemistry Website allows users to practice chemistry problems. This study involved the redesign of the Website using worked examples to enhance learner performance. The population sample for the study includes users (students and teachers) interested in learning descriptive chemistry materials. The users…

Organic and inorganic composition and microbiology of produced waters from Pennsylvania shale gas wells

USGS Publications Warehouse

Akob, Denise M.; Cozzarelli, Isabelle M.; Dunlap, Darren S.; Rowan, Elisabeth L.; Lorah, Michelle M.

2015-01-01

Hydraulically fractured shales are becoming an increasingly important source of natural gas production in the United States. This process has been known to create up to 420 gallons of produced water (PW) per day, but the volume varies depending on the formation, and the characteristics of individual hydraulic fracture. PW from hydraulic fracturing of shales are comprised of injected fracturing fluids and natural formation waters in proportions that change over time. Across the state of Pennsylvania, shale gas production is booming; therefore, it is important to assess the variability in PW chemistry and microbiology across this geographical span. We quantified the inorganic and organic chemical composition and microbial communities in PW samples from 13 shale gas wells in north central Pennsylvania. Microbial abundance was generally low (66–9400 cells/mL). Non-volatile dissolved organic carbon (NVDOC) was high (7–31 mg/L) relative to typical shallow groundwater, and the presence of organic acid anions (e.g., acetate, formate, and pyruvate) indicated microbial activity. Volatile organic compounds (VOCs) were detected in four samples (∼1 to 11.7 μg/L): benzene and toluene in the Burket sample, toluene in two Marcellus samples, and tetrachloroethylene (PCE) in one Marcellus sample. VOCs can be either naturally occurring or from industrial activity, making the source of VOCs unclear. Despite the addition of biocides during hydraulic fracturing, H2S-producing, fermenting, and methanogenic bacteria were cultured from PW samples. The presence of culturable bacteria was not associated with salinity or location; although organic compound concentrations and time in production were correlated with microbial activity. Interestingly, we found that unlike the inorganic chemistry, PW organic chemistry and microbial viability were highly variable across the 13 wells sampled, which can have important implications for the reuse and handling of these fluids

New chemistry of transition metal oxyhydrides

PubMed Central

Kobayashi, Yoji; Hernandez, Olivier; Tassel, Cédric; Kageyama, Hiroshi

2017-01-01

Abstract In this review we describe recent advances in transition metal oxyhydride chemistry obtained by topochemical routes, such as low temperature reduction with metal hydrides, or high-pressure solid-state reactions. Besides the crystal chemistry, magnetic and transport properties of the bulk powder and epitaxial thin film samples, the remarkable lability of the hydride anion is particularly highlighted as a new strategy to discover unprecedented mixed anion materials. PMID:29383042

Physical and Chemical Properties of the Copper-Alanine System: An Advanced Laboratory Project

ERIC Educational Resources Information Center

Farrell, John J.

1977-01-01

An integrated physical-analytical-inorganic chemistry laboratory procedure for use with undergraduate biology majors is described. The procedure requires five to six laboratory periods and includes acid-base standardizations, potentiometric determinations, computer usage, spectrophotometric determinations of crystal-field splitting…

Recent advances in magnetic resonance microscopy to the physical structure characterization of carbonaceous and inorganic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gregory, D.M.; Gerald, R.E.; Cody, G.D.

1997-04-01

Magnetic resonance microscopy (MRM) techniques have been employed to study the molecular architectures and properties of structural polymers, fossil fuels, microporous carbons and inorganic catalysts.

Beyond temperature: Clumped isotope signatures in dissolved inorganic carbon species and the influence of solution chemistry on carbonate mineral composition

NASA Astrophysics Data System (ADS)

Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B.; Henry, Drew

2015-10-01

;Clumped-isotope; thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 13C and 18O isotopes bound to each other within carbonate minerals in 13C18O16O22- groups (heavy isotope ;clumps;). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solution chemistry), several factors other than temperature, including dissolved inorganic carbon (DIC) speciation may influence mineral isotopic signatures. Therefore we used a combination of approaches to understand the potential influence of different variables on the clumped isotope (and oxygen isotope) composition of minerals. We conducted witherite precipitation experiments at a single temperature and at varied pH to empirically determine 13C-18O bond ordering (Δ47) and δ18O of CO32- and HCO3- molecules at a 25 °C equilibrium. Ab initio cluster models based on density functional theory were used to predict equilibrium 13C-18O bond abundances and δ18O of different DIC species and minerals as a function of temperature. Experiments and theory indicate Δ47 and δ18O compositions of CO32- and HCO3- ions are significantly different from each other. Experiments constrain the Δ47-δ18O slope for a pH effect (0.011 ± 0.001; 12 ⩾ pH ⩾ 7). Rapidly-growing temperate corals exhibit disequilibrium mineral isotopic signatures with a Δ47-δ18O slope of 0.011 ± 0.003, consistent with a pH effect. Our theoretical calculations for carbonate minerals indicate equilibrium lattice calcite values for Δ47 and δ18O are intermediate between HCO3- and CO32-. We analyzed synthetic calcites grown at temperatures ranging from 0.5 to 50 °C with and without the enzyme carbonic anhydrase present. This enzyme catalyzes oxygen isotopic exchange between DIC species and is present in many natural systems. The two

Beyond temperature: Clumped isotope signatures in dissolved inorganic carbon species and the influence of solution chemistry on carbonate mineral composition

USGS Publications Warehouse

Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B.; Henry, Drew

2015-01-01

“Clumped-isotope” thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 13C and 18O isotopes bound to each other within carbonate minerals in 13C18O16O22- groups (heavy isotope “clumps”). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solution chemistry), several factors other than temperature, including dissolved inorganic carbon (DIC) speciation may influence mineral isotopic signatures. Therefore we used a combination of approaches to understand the potential influence of different variables on the clumped isotope (and oxygen isotope) composition of minerals.We conducted witherite precipitation experiments at a single temperature and at varied pH to empirically determine 13C-18O bond ordering (Δ47) and δ18O of CO32- and HCO3- molecules at a 25 °C equilibrium. Ab initio cluster models based on density functional theory were used to predict equilibrium 13C-18O bond abundances and δ18O of different DIC species and minerals as a function of temperature. Experiments and theory indicate Δ47 and δ18O compositions of CO32- and HCO3- ions are significantly different from each other. Experiments constrain the Δ47-δ18O slope for a pH effect (0.011 ± 0.001; 12 ⩾ pH ⩾ 7). Rapidly-growing temperate corals exhibit disequilibrium mineral isotopic signatures with a Δ47-δ18O slope of 0.011 ± 0.003, consistent with a pH effect.Our theoretical calculations for carbonate minerals indicate equilibrium lattice calcite values for Δ47 and δ18O are intermediate between HCO3− and CO32−. We analyzed synthetic calcites grown at temperatures ranging from 0.5 to 50 °C with and without the enzyme carbonic anhydrase present. This enzyme catalyzes oxygen isotopic exchange between DIC species and is present in many

Chemistry Modeling for Aerothermodynamics and TPS

NASA Technical Reports Server (NTRS)

Wang, Dunyou; Stallcop, James R.; Dateo, Christopher e.; Schwenke, David W.; Halicioglu, Timur; Huo, winifred M.

2005-01-01

Recent advances in supercomputers and highly scalable quantum chemistry software render computational chemistry methods a viable means of providing chemistry data for aerothermal analysis at a specific level of confidence. Four examples of first principles quantum chemistry calculations will be presented. Study of the highly nonequilibrium rotational distribution of a nitrogen molecule from the exchange reaction N + N2 illustrates how chemical reactions can influence rotational distribution. The reaction C2H + H2 is one example of a radical reaction that occurs during hypersonic entry into an atmosphere containing methane. A study of the etching of a Si surface illustrates our approach to surface reactions. A recently developed web accessible database and software tool (DDD) that provides the radiation profile of diatomic molecules is also described.

Chemistry Modeling for Aerothermodynamics and TPS

NASA Technical Reports Server (NTRS)

Wang, Dun-You; Stallcop, James R.; Dateo, Christopher E.; Schwenke, David W.; Haliciogiu, Timur; Huo, Winifred

2004-01-01

Recent advances in supercomputers and highly scalable quantum chemistry software render computational chemistry methods a viable means of providing chemistry data for aerothermal analysis at a specific level of confidence. Four examples of first principles quantum chemistry calculations will be presented. The study of the highly nonequilibrium rotational distribution of nitrogen molecule from the exchange reaction N + N2 illustrates how chemical reactions can influence the rotational distribution. The reaction C2H + H2 is one example of a radical reaction that occurs during hypersonic entry into a methane containing atmosphere. A study of the etching of Si surface illustrates our approach to surface reactions. A recently developed web accessible database and software tool (DDD) that provides the radiation profile of diatomic molecules is also described.

Static Chemistry in Disks or Clouds

NASA Astrophysics Data System (ADS)

Semenov, D.; Wiebe, D.

2006-11-01

This FORTRAN77 code can be used to model static, time-dependent chemistry in ISM and circumstellar disks. Current version is based on the OSU'06 gas-grain astrochemical network with all updates to the reaction rates, and includes surface chemistry from Hasegawa & Herbst (1993) and Hasegawa, Herbst, and Leung (1992). Surface chemistry can be modeled either with the standard rate equation approach or modified rate equation approach (useful in disks). Gas-grain interactions include sticking of neutral molecules to grains, dissociative recombination of ions on grains as well as thermal, UV, X-ray, and CRP-induced desorption of frozen species. An advanced X-ray chemistry and 3 grain sizes with power-law size distribution are also included. An deuterium extension to this chemical model is available.

Mass spectrometry. [in organic chemistry

NASA Technical Reports Server (NTRS)

Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

1978-01-01

A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

Removing inorganics: Common methods have limits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorg, T.J.

1991-06-01

When EPA sets a regulation (a maximum contaminant level) for a contaminant, it must also specify the best available technology (BAT) that can be used to remove the contaminant. Because the regulations apply to community water systems, the technologies selected are ones that are commonly used to treat community size water systems. Thus, EPA R and D program has focused its efforts on evaluating primarily community applied technologies such as conventional coagulation-filtration, lime softening, ion exchange, adsorption, and membrane process. When BAT is identified for a specific contaminant, frequently the BAT will be listed with its limitations because the processmore » is often not effective under all water quality conditions. The same limitations would also apply to POU/POE treatment. The paper discusses EPA's regulations on inorganic contaminants, the best available technologies cited by EPA, and the limitations of the processes. Using arsenic as an example, the impact of the contaminant chemistry and water quality on removals is presented.« less

Dynamic combinatorial libraries: new opportunities in systems chemistry.

PubMed

Hunt, Rosemary A R; Otto, Sijbren

2011-01-21

Combinatorial chemistry is a tool for selecting molecules with special properties. Dynamic combinatorial chemistry started off aiming to be just that. However, unlike ordinary combinatorial chemistry, the interconnectedness of dynamic libraries gives them an extra dimension. An understanding of these molecular networks at systems level is essential for their use as a selection tool and creates exciting new opportunities in systems chemistry. In this feature article we discuss selected examples and considerations related to the advanced exploitation of dynamic combinatorial libraries for their originally conceived purpose of identifying strong binding interactions. Also reviewed are examples illustrating a trend towards increasing complexity in terms of network behaviour and reversible chemistry. Finally, new applications of dynamic combinatorial chemistry in self-assembly, transport and self-replication are discussed.

Diel variations in stream chemistry and isotopic composition of dissolved inorganic carbon, upper Clark Fork River, Montana, USA

USGS Publications Warehouse

Parker, Stephen R.; Gammons, Christopher H.; Poulson, Simon R.; DeGrandpre, Michael D.

2007-01-01

Many rivers undergo diel (24-h) concentration fluctuations of pH, dissolved gases, trace metals, nutrients, and other chemical species. A study conducted in 1994 documented such behavior in the upper Clark Fork River, Montana, a stream whose headwaters have been severely impacted by historic metal mining, milling, and smelting. The purpose of the present investigation was to expand on these earlier findings by conducting simultaneous diel samplings at two sites on the upper Clark Fork River separated by 2.5 h of stream travel time. By monitoring two stations, it was possible to more closely examine the processes that control temporal and spatial gradients in stream chemistry. Another objective was to examine diel changes in the δ13C composition of dissolved inorganic C (DIC) and their relationship to biological activity in the stream. The most important findings of this study include: (1) concentrations of dissolved and particulate heavy metals increased during the night and decreased during the day, in agreement with previous work; (2) these changes were positively correlated to diel changes in pH, dissolved O2, and water temperature; (3) dissolved concentrations increased during the night at the lower site, but showed the opposite behavior at the upper site; and (4) diel changes in δ13C-DIC were noted at both sites, although the timing and magnitudes of the cycles differed. Hypotheses to explain the first two observations include: cyclic co-precipitation of divalent metals with carbonate minerals; pH- and temperature-dependent sorption of metal cations onto the streambed and suspended particles; or photosynthetically enhanced oxidation and removal of Fe and Mn oxides at biofilm surfaces during the daytime. The latter model explains the majority of the field observations, including night-time increases in particulate forms of Fe and other elements.

In situ intercalation strategies for device-quality hybrid inorganic-organic self-assembled quantum wells

NASA Astrophysics Data System (ADS)

Pradeesh, K.; Baumberg, J. J.; Prakash, G. Vijaya

2009-07-01

Thin films of self-organized quantum wells of inorganic-organic hybrid perovskites of (C6H9C2H4NH3)2PbI4 are formed from a simple intercalation strategy to yield well-ordered uniform films over centimeter-size scales. These films compare favorably with traditional solution-chemistry-synthesized thin films. The hybrid films show strong room-temperature exciton-related absorption and photoluminescence, which shift with fabrication protocol. We demonstrate the potential of this method for electronic and photonic device applications.

Force-controlled inorganic crystallization lithography.

PubMed

Cheng, Chao-Min; LeDuc, Philip R

2006-09-20

Lithography plays a key role in integrated circuits, optics, information technology, biomedical applications, catalysis, and separation technologies. However, inorganic lithography techniques remain of limited utility for applications outside of the typical foci of integrated circuit manufacturing. In this communication, we have developed a novel stamping method that applies pressure on the upper surface of the stamp to regulate the dewetting process of the inorganic buffer and the evaporation rate of the solvent in this buffer between the substrate and the surface of the stamp. We focused on generating inorganic microstructures with specific locations and also on enabling the ability to pattern gradients during the crystallization of the inorganic salts. This approach utilized a combination of lithography with bottom-up growth and assembly of inorganic crystals. This work has potential applications in a variety of fields, including studying inorganic material patterning and small-scale fabrication technology.

TDPAC and β-NMR applications in chemistry and biochemistry

NASA Astrophysics Data System (ADS)

Jancso, Attila; Correia, Joao G.; Gottberg, Alexander; Schell, Juliana; Stachura, Monika; Szunyogh, Dániel; Pallada, Stavroula; Lupascu, Doru C.; Kowalska, Magdalena; Hemmingsen, Lars

2017-06-01

Time differential perturbed angular correlation (TDPAC) of γ-rays spectroscopy has been applied in chemistry and biochemistry for decades. Herein we aim to present a comprehensive review of chemical and biochemical applications of TDPAC spectroscopy conducted at ISOLDE over the past 15 years, including elucidation of metal site structure and dynamics in proteins and model systems. β-NMR spectroscopy is well established in nuclear physics, solid state physics, and materials science, but only a limited number of applications in chemistry have appeared. Current endeavors at ISOLDE advancing applications of β-NMR towards chemistry and biochemistry are presented, including the first experiment on 31Mg2+ in an ionic liquid solution. Both techniques require the production of radioisotopes combined with advanced spectroscopic instrumentation present at ISOLDE.

Advanced Experiments in Nuclear Science, Volume I: Advanced Nuclear Physics and Chemistry Experiments.

ERIC Educational Resources Information Center

Duggan, Jerome L.; And Others

The experiments in this manual represent state-of-the-art techniques which should be within the budgetary constraints of a college physics or chemistry department. There are fourteen experiments divided into five modules. The modules are on X-ray fluorescence, charged particle detection, neutron activation analysis, X-ray attenuation, and…

Synthesis and Spectra of Vanadium Complexes.

ERIC Educational Resources Information Center

Ophardt, Charles E.; Stupgia, Sean

1984-01-01

Describes an experiment which illustrates simple synthetic techniques, redox principles in synthesis reactions, interpretation of visible spectra using Orgel diagrams, and the spectrochemical series. The experiment is suitable for the advanced undergraduate inorganic chemistry laboratory. (JN)

Current status and future prospects for enabling chemistry technology in the drug discovery process.

PubMed

Djuric, Stevan W; Hutchins, Charles W; Talaty, Nari N

2016-01-01

This review covers recent advances in the implementation of enabling chemistry technologies into the drug discovery process. Areas covered include parallel synthesis chemistry, high-throughput experimentation, automated synthesis and purification methods, flow chemistry methodology including photochemistry, electrochemistry, and the handling of "dangerous" reagents. Also featured are advances in the "computer-assisted drug design" area and the expanding application of novel mass spectrometry-based techniques to a wide range of drug discovery activities.

Computing protein infrared spectroscopy with quantum chemistry.

PubMed

Besley, Nicholas A

2007-12-15

Quantum chemistry is a field of science that has undergone unprecedented advances in the last 50 years. From the pioneering work of Boys in the 1950s, quantum chemistry has evolved from being regarded as a specialized and esoteric discipline to a widely used tool that underpins much of the current research in chemistry today. This achievement was recognized with the award of the 1998 Nobel Prize in Chemistry to John Pople and Walter Kohn. As the new millennium unfolds, quantum chemistry stands at the forefront of an exciting new era. Quantitative calculations on systems of the magnitude of proteins are becoming a realistic possibility, an achievement that would have been unimaginable to the early pioneers of quantum chemistry. In this article we will describe ongoing work towards this goal, focusing on the calculation of protein infrared amide bands directly with quantum chemical methods.

Synthesis and Structural Characterization of New High-Valent Inorganic Fluorine Compounds and their Oxidizing Properties. Volume 3

DTIC Science & Technology

1992-02-01

COMPOUNDS AND T•EIR OXIDIZING PROPERTIES: VOLUME 3. Prof. G.J. Schrobilgen DTI.DTIC_* Mc Mastf-• University f ELECTE Department of Chemistry JUN 16...STRUCTURAL CHARACTERIZATION OF NEW HIGH- C - F49620-87-C-0049 VALENT INORGANIC FLUORINE COMPOUNDS AND THEIR OXIDIZING PR- 5730 PROPERTIES TA- 007C S6...fluorine, oxidizers of Neon, Krypton. Argon, and Xenon have been synthesized and characterized. KrF+ and ),eF+ caticmns have been made with neutral

Ultrasmooth organic-inorganic perovskite thin-film formation and crystallization for efficient planar heterojunction solar cells.

PubMed

Zhang, Wei; Saliba, Michael; Moore, David T; Pathak, Sandeep K; Hörantner, Maximilian T; Stergiopoulos, Thomas; Stranks, Samuel D; Eperon, Giles E; Alexander-Webber, Jack A; Abate, Antonio; Sadhanala, Aditya; Yao, Shuhua; Chen, Yulin; Friend, Richard H; Estroff, Lara A; Wiesner, Ulrich; Snaith, Henry J

2015-01-30

To date, there have been a plethora of reports on different means to fabricate organic-inorganic metal halide perovskite thin films; however, the inorganic starting materials have been limited to halide-based anions. Here we study the role of the anions in the perovskite solution and their influence upon perovskite crystal growth, film formation and device performance. We find that by using a non-halide lead source (lead acetate) instead of lead chloride or iodide, the perovskite crystal growth is much faster, which allows us to obtain ultrasmooth and almost pinhole-free perovskite films by a simple one-step solution coating with only a few minutes annealing. This synthesis leads to improved device performance in planar heterojunction architectures and answers a critical question as to the role of the anion and excess organic component during crystallization. Our work paves the way to tune the crystal growth kinetics by simple chemistry.

Inorganic and methane clathrates: Versatility of guest–host compounds for energy harvesting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishna, Lakshmi; Koh, Carolyn A.

ABSTRACT This review article evaluates the structure–property relations of inorganic clathrates and clathrate hydrates and their potential role in energy harvesting. There is potential cross-fertilization between the two research areas. Guest–host clathrate compounds exhibit unique structural and physical properties, which lead to their versatile roles in energy applications. Prominent classes of clathrate compounds are gas hydrates and inorganic clathrates. That said, there is limited cross-fertilization between the clathrate hydrate and inorganic clathrate communities, with researchers in the respective fields being less informed on the other field. Yet the structures and unique guest–host interactions in both these compounds are common importantmore » features of these clathrates. Common features and procedures can inspire and inform development between the compound classes, which may be important to the technological advancements for the different clathrate materials, e.g., structure characterization techniques and guest–host dynamics in which the “guest” tends to be imprisoned in the host structure, until external forces are applied. Conversely, the diversity in chemical compositions of these two classes of materials leads to the different applications from methane capture and storage to converting waste heat to electricity (thermoelectrics). This article highlights the structural and physical similarities and differences of inorganic and methane clathrates. The most promising state-of-the-art applications of the clathrates are highlighted for harvesting energy from methane (clathrate) hydrate deposits under the ocean and for inorganic clathrates as promising thermoelectric materials.« less

Inorganic and methane clathrates: Versatility of guest–host compounds for energy harvesting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishna, Lakshmi; Koh, Carolyn A.

2015-01-01

ABSTRACT This review article evaluates the structure–property relations of inorganic clathrates and clathrate hydrates and their potential role in energy harvesting. There is potential cross-fertilization between the two research areas. Guest–host clathrate compounds exhibit unique structural and physical properties, which lead to their versatile roles in energy applications. Prominent classes of clathrate compounds are gas hydrates and inorganic clathrates. That said, there is limited cross-fertilization between the clathrate hydrate and inorganic clathrate communities, with researchers in the respective fields being less informed on the other field. Yet the structures and unique guest–host interactions in both these compounds are common importantmore » features of these clathrates. Common features and procedures can inspire and inform development between the compound classes, which may be important to the technological advancements for the different clathrate materials, e.g., structure characterization techniques and guest–host dynamics in which the “guest” tends to be imprisoned in the host structure, until external forces are applied. Conversely, the diversity in chemical compositions of these two classes of materials leads to the different applications from methane capture and storage to converting waste heat to electricity (thermoelectrics). This article highlights the structural and physical similarities and differences of inorganic and methane clathrates. The most promising state-of-the-art applications of the clathrates are highlighted for harvesting energy from methane (clathrate) hydrate deposits under the ocean and for inorganic clathrates as promising thermoelectric materials.« less

Avogadro: an advanced semantic chemical editor, visualization, and analysis platform

PubMed Central

2012-01-01

Background The Avogadro project has developed an advanced molecule editor and visualizer designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science, and related areas. It offers flexible, high quality rendering, and a powerful plugin architecture. Typical uses include building molecular structures, formatting input files, and analyzing output of a wide variety of computational chemistry packages. By using the CML file format as its native document type, Avogadro seeks to enhance the semantic accessibility of chemical data types. Results The work presented here details the Avogadro library, which is a framework providing a code library and application programming interface (API) with three-dimensional visualization capabilities; and has direct applications to research and education in the fields of chemistry, physics, materials science, and biology. The Avogadro application provides a rich graphical interface using dynamically loaded plugins through the library itself. The application and library can each be extended by implementing a plugin module in C++ or Python to explore different visualization techniques, build/manipulate molecular structures, and interact with other programs. We describe some example extensions, one which uses a genetic algorithm to find stable crystal structures, and one which interfaces with the PackMol program to create packed, solvated structures for molecular dynamics simulations. The 1.0 release series of Avogadro is the main focus of the results discussed here. Conclusions Avogadro offers a semantic chemical builder and platform for visualization and analysis. For users, it offers an easy-to-use builder, integrated support for downloading from common databases such as PubChem and the Protein Data Bank, extracting chemical data from a wide variety of formats, including computational chemistry output, and native, semantic support for the CML file format. For developers, it can be

Avogadro: an advanced semantic chemical editor, visualization, and analysis platform.

PubMed

Hanwell, Marcus D; Curtis, Donald E; Lonie, David C; Vandermeersch, Tim; Zurek, Eva; Hutchison, Geoffrey R

2012-08-13

The Avogadro project has developed an advanced molecule editor and visualizer designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science, and related areas. It offers flexible, high quality rendering, and a powerful plugin architecture. Typical uses include building molecular structures, formatting input files, and analyzing output of a wide variety of computational chemistry packages. By using the CML file format as its native document type, Avogadro seeks to enhance the semantic accessibility of chemical data types. The work presented here details the Avogadro library, which is a framework providing a code library and application programming interface (API) with three-dimensional visualization capabilities; and has direct applications to research and education in the fields of chemistry, physics, materials science, and biology. The Avogadro application provides a rich graphical interface using dynamically loaded plugins through the library itself. The application and library can each be extended by implementing a plugin module in C++ or Python to explore different visualization techniques, build/manipulate molecular structures, and interact with other programs. We describe some example extensions, one which uses a genetic algorithm to find stable crystal structures, and one which interfaces with the PackMol program to create packed, solvated structures for molecular dynamics simulations. The 1.0 release series of Avogadro is the main focus of the results discussed here. Avogadro offers a semantic chemical builder and platform for visualization and analysis. For users, it offers an easy-to-use builder, integrated support for downloading from common databases such as PubChem and the Protein Data Bank, extracting chemical data from a wide variety of formats, including computational chemistry output, and native, semantic support for the CML file format. For developers, it can be easily extended via a powerful

Water oxidation chemistry of photosystem II.

PubMed Central

Vrettos, John S; Brudvig, Gary W

2002-01-01

The O(2)-evolving complex of photosystem II catalyses the light-driven four-electron oxidation of water to dioxygen in photosynthesis. In this article, the steps leading to photosynthetic O(2) evolution are discussed. Emphasis is given to the proton-coupled electron-transfer steps involved in oxidation of the manganese cluster by oxidized tyrosine Z (Y(*)(Z)), the function of Ca(2+) and the mechanism by which water is activated for formation of an O-O bond. Based on a consideration of the biophysical studies of photosystem II and inorganic manganese model chemistry, a mechanism for photosynthetic O(2) evolution is presented in which the O-O bond-forming step occurs via nucleophilic attack on an electron-deficient Mn(V)=O species by a calcium-bound water molecule. The proposed mechanism includes specific roles for the tetranuclear manganese cluster, calcium, chloride, Y(Z) and His190 of the D1 polypeptide. Recent studies of the ion selectivity of the calcium site in the O(2)-evolving complex and of a functional inorganic manganese model system that test key aspects of this mechanism are also discussed. PMID:12437878

Automated Water Chemistry Control at University of Virginia Pools.

ERIC Educational Resources Information Center

Krone, Dan

1997-01-01

Describes the technologically advanced aquatic and fitness center at the University of Virginia. Discusses the imprecise water chemistry control at the former facility and its intensive monitoring requirements. Details the new chemistry control standards initiated in the new center, which ensure constant chlorine and pH levels. (RJM)

An SOA model for toluene oxidation in the presence of inorganic aerosols.

PubMed

Cao, Gang; Jang, Myoseon

2010-01-15

A predictive model for secondary organic aerosol (SOA) formation including both partitioning and heterogeneous reactions is explored for the SOA produced from the oxidation of toluene in the presence of inorganic seed aerosols. The predictive SOA model comprises the explicit gas-phase chemistry of toluene, gas-particle partitioning, and heterogeneous chemistry. The resulting products from the explicit gas phase chemistry are lumped into several classes of chemical species based on their vapor pressure and reactivity for heterogeneous reactions. Both the gas-particle partitioning coefficient and the heterogeneous reaction rate constant of each lumped gas-phase product are theoretically determined using group contribution and molecular structure-reactivity. In the SOA model, the predictive SOA mass is decoupled into partitioning (OM(P)) and heterogeneous aerosol production (OM(H)). OM(P) is estimated from the SOA partitioning model developed by Schell et al. (J. Geophys. Res. 2001, 106, 28275-28293 ) that has been used in a regional air quality model (CMAQ 4.7). OM(H) is predicted from the heterogeneous SOA model developed by Jang et al. (Environ. Sci. Technol. 2006, 40, 3013-3022 ). The SOA model is evaluated using a number of the experimental SOA data that are generated in a 2 m(3) indoor Teflon film chamber under various experimental conditions (e.g., humidity, inorganic seed compositions, NO(x) concentrations). The SOA model reasonably predicts not only the gas-phase chemistry, such as the ozone formation, the conversion of NO to NO(2), and the toluene decay, but also the SOA production. The model predicted that the OM(H) fraction of the total toluene SOA mass increases as NO(x) concentrations decrease: 0.73-0.83 at low NO(x) levels and 0.17-0.47 at middle and high NO(x) levels for SOA experiments with high initial toluene concentrations. Our study also finds a significant increase in the OM(H) mass fraction in the SOA generated with low initial toluene

Development of inorganic resists for electron beam lithography: Novel materials and simulations

NASA Astrophysics Data System (ADS)

Jeyakumar, Augustin

Electron beam lithography is gaining widespread utilization as the semiconductor industry progresses towards both advanced optical and non-optical lithographic technologies for high resolution patterning. The current resist technologies are based on organic systems that are imaged most commonly through chain scission, networking, or a chemically amplified polarity change in the material. Alternative resists based on inorganic systems were developed and characterized in this research for high resolution electron beam lithography and their interactions with incident electrons were investigated using Monte Carlo simulations. A novel inorganic resist imaging scheme was developed using metal-organic precursors which decompose to form metal oxides upon electron beam irradiation that can serve as inorganic hard masks for hybrid bilayer inorganic-organic imaging systems and also as directly patternable high resolution metal oxide structures. The electron beam imaging properties of these metal-organic materials were correlated to the precursor structure by studying effects such as interactions between high atomic number species and the incident electrons. Optimal single and multicomponent precursors were designed for utilization as viable inorganic resist materials for sub-50nm patterning in electron beam lithography. The electron beam imaging characteristics of the most widely used inorganic resist material, hydrogen silsesquioxane (HSQ), was also enhanced using a dual processing imaging approach with thermal curing as well as a sensitizer catalyzed imaging approach. The interaction between incident electrons and the high atomic number species contained in these inorganic resists was also studied using Monte Carlo simulations. The resolution attainable using inorganic systems as compared to organic systems can be greater for accelerating voltages greater than 50 keV due to minimized lateral scattering in the high density inorganic systems. The effects of loading

Inorganic dual-layer microporous supported membranes

DOEpatents

Brinker, C. Jeffrey; Tsai, Chung-Yi; Lu, Yungfeng

2003-03-25

The present invention provides for a dual-layer inorganic microporous membrane capable of molecular sieving, and methods for production of the membranes. The inorganic microporous supported membrane includes a porous substrate which supports a first inorganic porous membrane having an average pore size of less than about 25 .ANG. and a second inorganic porous membrane coating the first inorganic membrane having an average pore size of less than about 6 .ANG.. The dual-layered membrane is produced by contacting the porous substrate with a surfactant-template polymeric sol, resulting in a surfactant sol coated membrane support. The surfactant sol coated membrane support is dried, producing a surfactant-templated polymer-coated substrate which is calcined to produce an intermediate layer surfactant-templated membrane. The intermediate layer surfactant-templated membrane is then contacted with a second polymeric sol producing a polymeric sol coated substrate which is dried producing an inorganic polymeric coated substrate. The inorganic polymeric coated substrate is then calcined producing an inorganic dual-layered microporous supported membrane in accordance with the present invention.

Current status and future prospects for enabling chemistry technology in the drug discovery process

PubMed Central

Djuric, Stevan W.; Hutchins, Charles W.; Talaty, Nari N.

2016-01-01

This review covers recent advances in the implementation of enabling chemistry technologies into the drug discovery process. Areas covered include parallel synthesis chemistry, high-throughput experimentation, automated synthesis and purification methods, flow chemistry methodology including photochemistry, electrochemistry, and the handling of “dangerous” reagents. Also featured are advances in the “computer-assisted drug design” area and the expanding application of novel mass spectrometry-based techniques to a wide range of drug discovery activities. PMID:27781094

Thermodynamic limit for synthesis of metastable inorganic materials.

PubMed

Aykol, Muratahan; Dwaraknath, Shyam S; Sun, Wenhao; Persson, Kristin A

2018-04-01

Realizing the growing number of possible or hypothesized metastable crystalline materials is extremely challenging. There is no rigorous metric to identify which compounds can or cannot be synthesized. We present a thermodynamic upper limit on the energy scale, above which the laboratory synthesis of a polymorph is highly unlikely. The limit is defined on the basis of the amorphous state, and we validate its utility by effectively classifying more than 700 polymorphs in 41 common inorganic material systems in the Materials Project for synthesizability. The amorphous limit is highly chemistry-dependent and is found to be in complete agreement with our knowledge of existing polymorphs in these 41 systems, whether made by the nature or in a laboratory. Quantifying the limits of metastability for realizable compounds, the approach is expected to find major applications in materials discovery.

Thermodynamic limit for synthesis of metastable inorganic materials

PubMed Central

2018-01-01

Realizing the growing number of possible or hypothesized metastable crystalline materials is extremely challenging. There is no rigorous metric to identify which compounds can or cannot be synthesized. We present a thermodynamic upper limit on the energy scale, above which the laboratory synthesis of a polymorph is highly unlikely. The limit is defined on the basis of the amorphous state, and we validate its utility by effectively classifying more than 700 polymorphs in 41 common inorganic material systems in the Materials Project for synthesizability. The amorphous limit is highly chemistry-dependent and is found to be in complete agreement with our knowledge of existing polymorphs in these 41 systems, whether made by the nature or in a laboratory. Quantifying the limits of metastability for realizable compounds, the approach is expected to find major applications in materials discovery. PMID:29725618

Inorganic Nanotubes and Fullerene-like Nanoparticles at the Crossroads between Solid-State Chemistry and Nanotechnology.

PubMed

Višić, Bojana; Panchakarla, Leela Srinivas; Tenne, Reshef

2017-09-20

Inorganic nanotubes (NTs) and fullerene-like nanoparticles (NPs) of WS 2 were discovered some 25 years ago and are produced now on a commercial scale for various applications. This Perspective provides a brief description of recent progress in this scientific discipline. The conceptual evolution leading to the discovery of these NTs and NPs is briefly discussed. Subsequently, recent progress in the synthesis of such NPs from a variety of inorganic compounds with layered (2D) structure is described. In particular, we discuss the synthesis of NTs from chalcogenide- and oxide-based ternary misfit layered compounds, as well as their structure and different growth mechanisms. Next we deliberate on the mechanical, optical, electrical, and electromechanical properties, which delineate them from their bulk counterparts and also from their graphene-like analogues. Here, different experiments with individual NTs coupled with first-principles and molecular dynamics calculations demonstrate the unique physical nature of these quasi-1D nanostructures. Finally, the various applications of the fullerene-like NPs of WS 2 and NTs formed therefrom are deliberated. Foremost among the possibilities are their extensive uses as superior solid lubricants. Combined with their nontoxicity and their facile dispersion, these NTs, with an ultimate strength of about 20 GPa, are likely to find numerous applications in reinforcing polymers, adhesives, textiles, medical devices, metallic alloys, and even concrete. Other potential applications in energy-harvesting and catalysis are discussed in brief.

Inorganic and Organometallic Molecular Wires for Single-Molecule Devices.

PubMed

Tanaka, Yuya; Kiguchi, Manabu; Akita, Munetaka

2017-04-06

Recent developments of single-molecule conductance measurements allow us to understand fundamental conducting properties of molecular wires. While a wide variety of organic molecular wires have been studied so far, inorganic and organometallic molecular wires have received much less attention. However, molecular wires with transition-metal atoms show interesting features and functions distinct from those of organic wires. These properties originate mainly from metal-ligand dπ-pπ interactions and metal-metal d-d interactions. Thanks to the rich combination of metal atoms and supporting ligands, frontier orbital energies of the molecular wires can be finely tuned to lead to highly conducting molecular wires. Moreover, the unique electronic structures of metal complexes are susceptible to subtle environmental changes, leading to potential functional molecular devices. This article reviews recent advances in the single-molecule conductance study of inorganic and organometallic molecular wires. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evolution of water chemistry during Marcellus Shale gas development: A case study in West Virginia.

PubMed

Ziemkiewicz, Paul F; Thomas He, Y

2015-09-01

Hydraulic fracturing (HF) has been used with horizontal drilling to extract gas and natural gas liquids from source rock such as the Marcellus Shale in the Appalachian Basin. Horizontal drilling and HF generates large volumes of waste water known as flowback. While inorganic ion chemistry has been well characterized, and the general increase in concentration through the flowback is widely recognized, the literature contains little information relative to organic compounds and radionuclides. This study examined the chemical evolution of liquid process and waste streams (including makeup water, HF fluids, and flowback) in four Marcellus Shale gas well sites in north central West Virginia. Concentrations of organic and inorganic constituents and radioactive isotopes were measured to determine changes in waste water chemistry during shale gas development. We found that additives used in fracturing fluid may contribute to some of the constituents (e.g., Fe) found in flowback, but they appear to play a minor role. Time sequence samples collected during flowback indicated increasing concentrations of organic, inorganic and radioactive constituents. Nearly all constituents were found in much higher concentrations in flowback water than in injected HF fluids suggesting that the bulk of constituents originate in the Marcellus Shale formation rather than in the formulation of the injected HF fluids. Liquid wastes such as flowback and produced water, are largely recycled for subsequent fracturing operations. These practices limit environmental exposure to flowback. Copyright © 2015 Elsevier Ltd. All rights reserved.

Understanding Differences in Chemistry Climate Model Projections of Stratospheric Ozone

NASA Technical Reports Server (NTRS)

Douglass, A. R.; Strahan, S. E.; Oman, L. D.; Stolarski, R. S.

2014-01-01

Chemistry climate models (CCMs) are used to project future evolution of stratospheric ozone as concentrations of ozone-depleting substances (ODSs) decrease and greenhouse gases increase, cooling the stratosphere. CCM projections exhibit not only many common features but also a broad range of values for quantities such as year of ozone return to 1980 and global ozone level at the end of the 21st century. Multiple linear regression is applied to each of 14 CCMs to separate ozone response to ODS concentration change from that due to climate change. We show that the sensitivity of lower stratospheric ozone to chlorine change Delta Ozone/Delta inorganic chlorine is a near-linear function of partitioning of total inorganic chlorine into its reservoirs; both inorganic chlorine and its partitioning are largely controlled by lower stratospheric transport. CCMs with best performance on transport diagnostics agree with observations for chlorine reservoirs and produce similar ozone responses to chlorine change. After 2035, differences in Delta Ozone/Delta inorganic chlorine contribute little to the spread in CCM projections as the anthropogenic contribution to inorganic chlorine becomes unimportant. Differences among upper stratospheric ozone increases due to temperature decreases are explained by differences in ozone sensitivity to temperature change Delta Ozone/Delta T due to different contributions from various ozone loss processes, each with its own temperature dependence. Ozone decrease in the tropical lower stratosphere caused by a projected speedup in the Brewer-Dobson circulation may or may not be balanced by ozone increases in the middle- and high-latitude lower stratosphere and upper troposphere. This balance, or lack thereof, contributes most to the spread in late 21st century projections.

Carbohydrates in Supramolecular Chemistry.

PubMed

Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

2016-02-24

Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed.

The Chemistry of Health.

ERIC Educational Resources Information Center

National Inst. of General Medical Sciences (NIH), Bethesda, MD.

This booklet, geared toward an advanced high school or early college-level audience, describes how basic chemistry and biochemistry research can spur a better understanding of human health. It reveals how networks of chemical reactions keep our bodies running smoothly. Some of the tools and technologies used to explore these reactions are…

Supramolecular chemistry: from molecular information towards self-organization and complex matter

NASA Astrophysics Data System (ADS)

Lehn, Jean-Marie

2004-03-01

Molecular chemistry has developed a wide range of very powerful procedures for constructing ever more sophisticated molecules from atoms linked by covalent bonds. Beyond molecular chemistry lies supramolecular chemistry, which aims at developing highly complex chemical systems from components interacting via non-covalent intermolecular forces. By the appropriate manipulation of these interactions, supramolecular chemistry became progressively the chemistry of molecular information, involving the storage of information at the molecular level, in the structural features, and its retrieval, transfer, and processing at the supramolecular level, through molecular recognition processes operating via specific interactional algorithms. This has paved the way towards apprehending chemistry also as an information science. Numerous receptors capable of recognizing, i.e. selectively binding, specific substrates have been developed, based on the molecular information stored in the interacting species. Suitably functionalized receptors may perform supramolecular catalysis and selective transport processes. In combination with polymolecular organization, recognition opens ways towards the design of molecular and supramolecular devices based on functional (photoactive, electroactive, ionoactive, etc) components. A step beyond preorganization consists in the design of systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined supramolecular architectures by self-assembly from their components. Self-organization processes, directed by the molecular information stored in the components and read out at the supramolecular level through specific interactions, represent the operation of programmed chemical systems. They have been implemented for the generation of a variety of discrete functional architectures of either organic or inorganic nature. Self-organization processes also give access to advanced supramolecular materials, such as

Remote Monitoring, Inorganic Monitoring

EPA Science Inventory

This chapter provides an overview of applicability, amenability, and operating parameter ranges for various inorganic parameters:this chapter will also provide a compilation of existing and new online technologies for determining inorganic compounds in water samples. A wide vari...

General route for the assembly of functional inorganic capsules.

PubMed

Akartuna, Ilke; Tervoort, Elena; Studart, André R; Gauckler, Ludwig J

2009-11-03

Semipermeable, hollow capsules are attractive materials for the encapsulation and delivery of active agents in food processing, pharmaceutical and agricultural industries, and biomedicine. These capsules can be produced by forming a solid shell of close packed colloidal particles, typically polymeric particles, at the surface of emulsion droplets. However, current methods to prepare such capsules may involve multistep chemical procedures to tailor the surface chemistry of particles or are limited to particles that exhibit inherently the right hydrophobic-hydrophilic balance to adsorb around emulsion droplets. In this work, we describe a general and simple method to fabricate semipermeable, inorganic capsules from emulsion droplets stabilized by a wide variety of colloidal metal oxide particles. The assembly of particles at the oil-water interface is induced by the in situ hydrophobization of the particle surface through the adsorption of short amphiphilic molecules. The adsorption of particles at the interface leads to stable capsules comprising a single layer of particles in the outer shell. Such capsules can be used in the wet state or can be further processed into dry capsules. The permeability of the capsules can be modified by filling the interstices between the shell particles with polymeric or inorganic species. Functional capsules with biocompatible, bioresorbable, heat-resistant, chemical-resistant, and magnetic properties were prepared using alumina, silica, iron oxide, or tricalcium phosphate as particles in the shell.

Biomineralization-inspired synthesis of functional organic/inorganic hybrid materials: organic molecular control of self-organization of hybrids.

PubMed

Arakaki, Atsushi; Shimizu, Katsuhiko; Oda, Mayumi; Sakamoto, Takeshi; Nishimura, Tatsuya; Kato, Takashi

2015-01-28

Organisms produce various organic/inorganic hybrid materials, which are called biominerals. They form through the self-organization of organic molecules and inorganic elements under ambient conditions. Biominerals often have highly organized and hierarchical structures from nanometer to macroscopic length scales, resulting in their remarkable physical and chemical properties that cannot be obtained by simple accumulation of their organic and inorganic constituents. These observations motivate us to create novel functional materials exhibiting properties superior to conventional materials--both synthetic and natural. Herein, we introduce recent progress in understanding biomineralization processes at the molecular level and the development of organic/inorganic hybrid materials by these processes. We specifically outline fundamental molecular studies on silica, iron oxide, and calcium carbonate biomineralization and describe material synthesis based on these mechanisms. These approaches allow us to design a variety of advanced hybrid materials with desired morphologies, sizes, compositions, and structures through environmentally friendly synthetic routes using functions of organic molecules.

Role of Metabolism in Arsenic-Induced Toxicity: Identification and Quantification of Arsenic Metabolites in Tissues and Excreta

EPA Science Inventory

Arsenic is a known toxicant and carcinogen. Methylation of inorganic arsenic was once thought to be a detoxification mechanism because of the rapid excretion and relatively lower toxicity of the pentavalent organic arsenical metabolites. Advances in analytical chemistry have al...

Inorganic Crystal Structure Database (ICSD)

National Institute of Standards and Technology Data Gateway

SRD 84 FIZ/NIST Inorganic Crystal Structure Database (ICSD) (PC database for purchase)   The Inorganic Crystal Structure Database (ICSD) is produced cooperatively by the Fachinformationszentrum Karlsruhe(FIZ) and the National Institute of Standards and Technology (NIST). The ICSD is a comprehensive collection of crystal structure data of inorganic compounds containing more than 140,000 entries and covering the literature from 1915 to the present.

Deciphering the Complex Chemistry of Deep-Ocean Particles Using Complementary Synchrotron X-ray Microscope and Microprobe Instruments.

PubMed

Toner, Brandy M; German, Christopher R; Dick, Gregory J; Breier, John A

2016-01-19

The reactivity and mobility of natural particles in aquatic systems have wide ranging implications for the functioning of Earth surface systems. Particles in the ocean are biologically and chemically reactive, mobile, and complex in composition. The chemical composition of marine particles is thought to be central to understanding processes that convert globally relevant elements, such as C and Fe, among forms with varying bioavailability and mobility in the ocean. The analytical tools needed to measure the complex chemistry of natural particles are the subject of this Account. We describe how a suite of complementary synchrotron radiation instruments with nano- and micrometer focusing, and X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) capabilities are changing our understanding of deep-ocean chemistry and life. Submarine venting along mid-ocean ridges creates hydrothermal plumes where dynamic particle-forming reactions occur as vent fluids mix with deep-ocean waters. Whether plumes are net sources or sinks of elements in ocean budgets depends in large part on particle formation, reactivity, and transport properties. Hydrothermal plume particles have been shown to host microbial communities and exhibit complex size distributions, aggregation behavior, and composition. X-ray microscope and microprobe instruments can address particle size and aggregation, but their true strength is in measuring chemical composition. Plume particles comprise a stunning array of inorganic and organic phases, from single-crystal sulfides to poorly ordered nanophases and polymeric organic matrices to microbial cells. X-ray microscopes and X-ray microprobes with elemental imaging, XAS, and XRD capabilities are ideal for investigating these complex materials because they can (1) measure the chemistry of organic and inorganic constituents in complex matrices, usually within the same particle or aggregate, (2) provide strong signal-to-noise data with exceedingly small

Tracing river chemistry in space and time: Dissolved inorganic constituents of the Fraser River, Canada

NASA Astrophysics Data System (ADS)

Voss, Britta M.; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy I.; Fiske, Gregory; Wang, Zhaohui Aleck; Hoering, Katherine A.; Montluçon, Daniel B.; LeCroy, Chase; Pal, Sharmila; Marsh, Steven; Gillies, Sharon L.; Janmaat, Alida; Bennett, Michelle; Downey, Bryce; Fanslau, Jenna; Fraser, Helena; Macklam-Harron, Garrett; Martinec, Michelle; Wiebe, Brayden

2014-01-01

The Fraser River basin in southwestern Canada bears unique geologic and climatic features which make it an ideal setting for investigating the origins, transformations and delivery to the coast of dissolved riverine loads under relatively pristine conditions. We present results from sampling campaigns over three years which demonstrate the lithologic and hydrologic controls on fluxes and isotope compositions of major dissolved inorganic runoff constituents (dissolved nutrients, major and trace elements, 87Sr/86Sr, δD). A time series record near the Fraser mouth allows us to generate new estimates of discharge-weighted concentrations and fluxes, and an overall chemical weathering rate of 32 t km-2 y-1. The seasonal variations in dissolved inorganic species are driven by changes in hydrology, which vary in timing across the basin. The time series record of dissolved 87Sr/86Sr is of particular interest, as a consistent shift between higher (“more radiogenic”) values during spring and summer and less radiogenic values in fall and winter demonstrates the seasonal variability in source contributions throughout the basin. This seasonal shift is also quite large (0.709-0.714), with a discharge-weighted annual average of 0.7120 (2 s.d. = 0.0003). We present a mixing model which predicts the seasonal evolution of dissolved 87Sr/86Sr based on tributary compositions and water discharge. This model highlights the importance of chemical weathering fluxes from the old sedimentary bedrock of headwater drainage regions, despite their relatively small contribution to the total water flux.

Chemical characteristics of size-resolved atmospheric aerosols in Iasi, north-eastern Romania: nitrogen-containing inorganic compounds control aerosol chemistry in the area

NASA Astrophysics Data System (ADS)

Giorgiana Galon-Negru, Alina; Iulian Olariu, Romeo; Arsene, Cecilia

2018-04-01

This study assesses the effects of particle size and season on the content of the major inorganic and organic aerosol ionic components in the Iasi urban area, north-eastern Romania. Continuous measurements were carried out over 2016 using a cascade Dekati low-pressure impactor (DLPI) performing aerosol size classification in 13 specific fractions over the 0.0276-9.94 µm size range. Fine-particulate Cl-, NO3-, NH4+, and K+ exhibited clear minima during the warm season and clear maxima over the cold season, mainly due to trends in emission sources, changes in the mixing layer depth and specific meteorological conditions. Fine-particulate SO42- did not show much variation with respect to seasons. Particulate NH4+ and NO3- ions were identified as critical parameters controlling aerosol chemistry in the area, and their measured concentrations in fine-mode (PM2.5) aerosols were found to be in reasonable good agreement with modelled values for winter but not for summer. The likely reason is that NH4NO3 aerosols are lost due to volatility over the warm season. We found that NH4+ in PM2.5 is primarily associated with SO42- and NO3- but not with Cl-. Actually, indirect ISORROPIA-II estimations showed that the atmosphere in the Iasi area might be ammonia rich during both the cold and warm seasons, enabling enough NH3 to be present to neutralize H2SO4, HNO3, and HCl acidic components and to generate fine-particulate ammonium salts, in the form of (NH4)2SO4, NH4NO3, and NH4Cl. ISORROPIA-II runs allowed us to estimate that over the warm season ˜ 35 % of the total analysed samples had very strongly acidic pH (0-3), a fraction that rose to ˜ 43 % over the cold season. Moreover, while in the cold season the acidity is mainly accounted for by inorganic acids, in the warm ones there is an important contribution by other compounds, possibly organic. Indeed, changes in aerosol acidity would most likely impact the gas-particle partitioning of semi-volatile organic acids. Overall, we

Organic nutrient chemistry and the marine microbiome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Repeta, Daniel J.; Boiteau, Rene M.

Vast expanses of the ocean are characterized by extraordinarily low concentrations of nutrients but nevertheless support vibrant communities of marine microbes. In aggregate, these communities drive many of the important elemental cycles that sustain life on Earth. Microbial communities are organized to maximize nutrient and energy transfer between cells, and efficiently recycle organic carbon, nitrogen, phosphorus and trace metals. Energy and nutrient transfer occurs across a broad range of spatial scales. Large-sized marine algae and bacteria support epibiont communities that are physically in contact, exchanging nutrients and energy across cell membranes, while other communities that are physically far apart, relymore » on the horizontal mixing of ocean currents or the vertical pull of gravity to transfer nutrient and energy containing organic matter. Marine organic geochemists are making rapid progress in understanding the chemistry of the marine microbiome. These advances have benefited from parallel developments in analytical chemistry, microbial isolation and culture techniques, and advances in microbial genomics, transcriptomics, and proteomics. The combination of all three approaches has proven to be quite powerful. Here we highlight two aspects of the chemistry of organic phosphorus and trace metal cycling and the marine microbiome. In each study, advances in chemical analyses, microbial culture, and microbial genomics played key roles in understanding how microbial communities interact to facilitate nutrient cycling in the open ocean.« less

Room-temperature ductile inorganic semiconductor.

PubMed

Shi, Xun; Chen, Hongyi; Hao, Feng; Liu, Ruiheng; Wang, Tuo; Qiu, Pengfei; Burkhardt, Ulrich; Grin, Yuri; Chen, Lidong

2018-05-01

Ductility is common in metals and metal-based alloys, but is rarely observed in inorganic semiconductors and ceramic insulators. In particular, room-temperature ductile inorganic semiconductors were not known until now. Here, we report an inorganic α-Ag 2 S semiconductor that exhibits extraordinary metal-like ductility with high plastic deformation strains at room temperature. Analysis of the chemical bonding reveals systems of planes with relatively weak atomic interactions in the crystal structure. In combination with irregularly distributed silver-silver and sulfur-silver bonds due to the silver diffusion, they suppress the cleavage of the material, and thus result in unprecedented ductility. This work opens up the possibility of searching for ductile inorganic semiconductors/ceramics for flexible electronic devices.

Room-temperature ductile inorganic semiconductor

NASA Astrophysics Data System (ADS)

Shi, Xun; Chen, Hongyi; Hao, Feng; Liu, Ruiheng; Wang, Tuo; Qiu, Pengfei; Burkhardt, Ulrich; Grin, Yuri; Chen, Lidong

2018-05-01

Ductility is common in metals and metal-based alloys, but is rarely observed in inorganic semiconductors and ceramic insulators. In particular, room-temperature ductile inorganic semiconductors were not known until now. Here, we report an inorganic α-Ag2S semiconductor that exhibits extraordinary metal-like ductility with high plastic deformation strains at room temperature. Analysis of the chemical bonding reveals systems of planes with relatively weak atomic interactions in the crystal structure. In combination with irregularly distributed silver-silver and sulfur-silver bonds due to the silver diffusion, they suppress the cleavage of the material, and thus result in unprecedented ductility. This work opens up the possibility of searching for ductile inorganic semiconductors/ceramics for flexible electronic devices.

Computational chemistry

NASA Technical Reports Server (NTRS)

Arnold, J. O.

1987-01-01

With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

Advances in dental materials.

PubMed

Fleming, Garry J P

2014-05-01

The dental market is replete with new resorative materials marketed on the basis of novel technological advances in materials chemistry, bonding capability or reduced operator time and/or technique sensitivity. This paper aims to consider advances in current materials, with an emphasis on their role in supporting contemporary clinical practice.

Inorganic Nanoporous Membranes for Immunoisolated Cell-Based Drug Delivery

PubMed Central

Mendelsohn, Adam; Desai, Tejal

2014-01-01

Materials advances enabled by nanotechnology have brought about promising approaches to improve the encapsulation mechanism for immunoisolated cell-based drug delivery. Cell-based drug delivery is a promising treatment for many diseases but has thus far achieved only limited clinical success. Treatment of insulin dependent diabetes mellitus (IDDM) by transplantation of pancreatic β-cells represents the most anticipated application of cell-based drug delivery technology. This review outlines the challenges involved with maintaining transplanted cell viability and discusses how inorganic nanoporous membranes may be useful in achieving clinical success. PMID:20384222

Recent Advances in the Chemistry and Biology of Podophyllotoxins.

PubMed

Yu, Xiang; Che, Zhiping; Xu, Hui

2017-04-03

Podophyllotoxin and its related aryltetralin cyclolignans belong to a family of important products that exhibit various biological properties (e.g., cytotoxic, insecticidal, antifungal, antiviral, anti-inflammatory, neurotoxic, immunosuppressive, antirheumatic, antioxidative, antispasmogenic, and hypolipidemic activities). This Review provides a survey of podophyllotoxin and its analogues isolated from plants. In particular, recent developments in the elegant total chemical synthesis, structural modifications, biosynthesis, and biotransformation of podophyllotoxin and its analogues are summarized. Moreover, a deoxypodophyllotoxin-based chemosensor for selective detection of mercury ion is described. In addition to the most active podophyllotoxin derivatives in each series against human cancer cell lines and insect pests listed in the tables, the structure-activity relationships of podophyllotoxin derivatives as cytotoxic and insecticidal agents are also outlined. Future prospects and further developments in this area are covered at the end of the Review. We believe that this Review will provide necessary information for synthetic, medicinal, and pesticidal chemistry researchers who are interested in the chemistry and biology of podophyllotoxins. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

"Rinse and trickle": a protocol for TEM preparation and investigation of inorganic fibers from biological material.

PubMed

Vigliaturo, Ruggero; Capella, Silvana; Rinaudo, Caterina; Belluso, Elena

2016-07-01

The purpose of this work is to define a sample preparation protocol that allows inorganic fibers and particulate matter extracted from different biological samples to be characterized morphologically, crystallographically and chemically by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). The method does not damage or create artifacts through chemical attacks of the target material. A fairly rapid specimen preparation is applied with the aim of performing as few steps as possible to transfer the withdrawn inorganic matter onto the TEM grid. The biological sample is previously digested chemically by NaClO. The salt is then removed through a series of centrifugation and rinse cycles in deionized water, thus drastically reducing the digestive power of the NaClO and concentrating the fibers for TEM analysis. The concept of equivalent hydrodynamic diameter is introduced to calculate the settling velocity during the centrifugation cycles. This technique is applicable to lung tissues and can be extended to a wide range of organic materials. The procedure does not appear to cause morphological damage to the fibers or modify their chemistry or degree of crystallinity. The extrapolated data can be used in interdisciplinary studies to understand the pathological effects caused by inorganic materials.

The chemistry of peroxovanadium compounds relevant to insulin mimesis.

PubMed

Shaver, A; Ng, J B; Hall, D A; Posner, B I

The inorganic coordination chemistry of peroxovanadium compounds relevant to insulin mimesis is reviewed. The structure and kinetic reactivity of solutions of vanadate anion, vanadyl complexes and peroxovanadate complexes are briefly compared. Peroxovanadium compounds contain an oxo group, one or two peroxo ligands (O2(2-)) and an ancillary ligand which is usually bidentate. These compounds approximate a trigonal bipyramidal structure which can be divided conceptually into a polar 'oxo' half and a relatively non-polar organic half. This presents a number of interesting design variations which are discussed with respect to the development of a rudimentary structure-activity correlation of insulin mimetic ability.

Advances in design and modeling of porous materials

NASA Astrophysics Data System (ADS)

Ayral, André; Calas-Etienne, Sylvie; Coasne, Benoit; Deratani, André; Evstratov, Alexis; Galarneau, Anne; Grande, Daniel; Hureau, Matthieu; Jobic, Hervé; Morlay, Catherine; Parmentier, Julien; Prelot, Bénédicte; Rossignol, Sylvie; Simon-Masseron, Angélique; Thibault-Starzyk, Frédéric

2015-07-01

This special issue of the European Physical Journal Special Topics is dedicated to selected papers from the symposium "High surface area porous and granular materials" organized in the frame of the conference "Matériaux 2014", held on November 24-28, 2014 in Montpellier, France. Porous materials and granular materials gather a wide variety of heterogeneous, isotropic or anisotropic media made of inorganic, organic or hybrid solid skeletons, with open or closed porosity, and pore sizes ranging from the centimeter scale to the sub-nanometer scale. Their technological and industrial applications cover numerous areas from building and civil engineering to microelectronics, including also metallurgy, chemistry, health, waste water and gas effluent treatment. Many emerging processes related to environmental protection and sustainable development also rely on this class of materials. Their functional properties are related to specific transfer mechanisms (matter, heat, radiation, electrical charge), to pore surface chemistry (exchange, adsorption, heterogeneous catalysis) and to retention inside confined volumes (storage, separation, exchange, controlled release). The development of innovative synthesis, shaping, characterization and modeling approaches enables the design of advanced materials with enhanced functional performance. The papers collected in this special issue offer a good overview of the state-of-the-art and science of these complex media. We would like to thank all the speakers and participants for their contribution to the success of the symposium. We also express our gratitude to the organization committee of "Matériaux 2014". We finally thank the reviewers and the staff of the European Physical Journal Special Topics who made the publication of this special issue possible.

Phage as a Genetically Modifiable Supramacromolecule in Chemistry, Materials and Medicine.

PubMed

Cao, Binrui; Yang, Mingying; Mao, Chuanbin

2016-06-21

Filamentous bacteriophage (phage) is a genetically modifiable supramacromolecule. It can be pictured as a semiflexible nanofiber (∼900 nm long and ∼8 nm wide) made of a DNA core and a protein shell with the former genetically encoding the latter. Although phage bioengineering and phage display techniques were developed before the 1990s, these techniques have not been widely used for chemistry, materials, and biomedical research from the perspective of supramolecular chemistry until recently. Powered by our expertise in displaying a foreign peptide on its surface through engineering phage DNA, we have employed phage to identify target-specific peptides, construct novel organic-inorganic nanohybrids, develop biomaterials for disease treatment, and generate bioanalytical methods for disease diagnosis. Compared with conventional biomimetic chemistry, phage-based supramolecular chemistry represents a new frontier in chemistry, materials science, and medicine. In this Account, we introduce our recent successful efforts in phage-based supramolecular chemistry, by integrating the unique nanofiber-like phage structure and powerful peptide display techniques into the fields of chemistry, materials science, and medicine: (1) successfully synthesized and assembled silica, hydroxyapatite, and gold nanoparticles using phage templates to form novel functional materials; (2) chemically introduced azo units onto the phage to form photoresponsive functional azo-phage nanofibers via a diazotization reaction between aromatic amino groups and the tyrosine residues genetically displayed on phage surfaces; (3) assembled phage into 2D films for studying the effects of both biochemical (the peptide sequences displayed on the phages) and biophysical (the topographies of the phage films) cues on the proliferation and differentiation of mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs) and identified peptides and topographies that can induce their osteogenic

Phage as a Genetically Modifiable Supramacromolecule in Chemistry, Materials and Medicine

PubMed Central

Cao, Binrui; Yang, Mingying; Mao, Chuanbin

2016-01-01

CONSPECTUS Filamentous bacteriophage (phage) is a genetically modifiable supramacromolecule. It can be pictured as a semiflexible nanofiber (~900 nm long and ~8 nm wide) made of a DNA core and a protein shell with the former genetically encoding the latter. Although phage bioengineering and phage display techniques were developed before the 1990s, these techniques have not been widely used for chemistry, materials, and biomedical research from the perspective of supramolecular chemistry until recently. Powered by our expertise in displaying a foreign peptide on its surface through engineering phage DNA, we have employed phage to identify target-specific peptides, construct novel organic–inorganic nanohybrids, develop biomaterials for disease treatment, and generate bioanalytical methods for disease diagnosis. Compared with conventional biomimetic chemistry, phage-based supramolecular chemistry represents a new frontier in chemistry, materials science, and medicine. In this Account, we introduce our recent successful efforts in phage-based supramolecular chemistry, by integrating the unique nanofiber-like phage structure and powerful peptide display techniques into the fields of chemistry, materials science, and medicine: (1) successfully synthesized and assembled silica, hydroxyapatite, and gold nanoparticles using phage templates to form novel functional materials; (2) chemically introduced azo units onto the phage to form photoresponsive functional azo-phage nanofibers via a diazotization reaction between aromatic amino groups and the tyrosine residues genetically displayed on phage surfaces; (3) assembled phage into 2D films for studying the effects of both biochemical (the peptide sequences displayed on the phages) and biophysical (the topographies of the phage films) cues on the proliferation and differentiation of mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs) and identified peptides and topographies that can induce their

Ultrahigh Performance C60 Nanorod Large Area Flexible Photoconductor Devices via Ultralow Organic and Inorganic Photodoping

PubMed Central

Saran, Rinku; Stolojan, Vlad; Curry, Richard J.

2014-01-01

One dimensional single-crystal nanorods of C60 possess unique optoelectronic properties including high electron mobility, high photosensitivity and an excellent electron accepting nature. In addition, their rapid large scale synthesis at room temperature makes these organic semiconducting nanorods highly attractive for advanced optoelectronic device applications. Here, we report low-cost large-area flexible photoconductor devices fabricated using C60 nanorods. We demonstrate that the photosensitivity of the C60 nanorods can be enhanced ~400-fold via an ultralow photodoping mechanism. The photodoped devices offer broadband UV-vis-NIR spectral tuneability, exhibit a detectivitiy >109 Jones, an external quantum efficiency of ~100%, a linear dynamic range of 80 dB, a rise time 60 µs and the ability to measure ac signals up to ~250 kHz. These figures of merit combined are among the highest reported for one dimensional organic and inorganic large-area planar photoconductors and are competitive with commercially available inorganic photoconductors and photoconductive cells. With the additional processing benefits providing compatibility with large-area flexible platforms, these devices represent significant advances and make C60 nanorods a promising candidate for advanced photodetector technologies. PMID:24853479

Inorganic aerosols responses to emission changes in Yangtze River Delta, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Xinyi; Li, Juan; Fu, Joshua S.

2014-05-15

China announced the Chinese National Ambient Air Quality standards (CH-NAAQS) on Feb. 29th, 2012, and PM2.5 is for the very first time included in the standards as a criteria pollutant. In order to probe into PM2.5 pollution over Yangtze River Delta, which is one of the major urban clusters hosting more than 80 million people in China, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Both simulation and observation demonstrated that, inorganic aerosols have substantial contributions to PM2.5 overmore » YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3-) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3-concentration throughout the year. We also found that in winter NO3- was even increased under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4+) and sulfate (SO42-), while other seasons showed decrease response of NO3-. Sensitivity responses of NO3- under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3- formation was actually VOC sensitive due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols.« less

Semiconducting organic-inorganic nanocomposites by intimately tethering conjugated polymers to inorganic tetrapods

NASA Astrophysics Data System (ADS)

Jung, Jaehan; Yoon, Young Jun; Lin, Zhiqun

2016-04-01

Semiconducting organic-inorganic nanocomposites were judiciously crafted by placing conjugated polymers in intimate contact with inorganic tetrapods via click reaction. CdSe tetrapods were first synthesized by inducing elongated arms from CdSe zincblende seeds through seed-mediated growth. The subsequent effective inorganic ligand treatment, followed by reacting with short bifunctional ligands, yielded azide-functionalized CdSe tetrapods (i.e., CdSe-N3). Finally, the ethynyl-terminated conjugated polymer poly(3-hexylthiophene) (i.e., P3HT-&z.tbd;) was tethered to CdSe-N3 tetrapods via a catalyst-free alkyne-azide cycloaddition, forming intimate semiconducting P3HT-CdSe tetrapod nanocomposites. Intriguingly, the intimate contact between P3HT and CdSe tetrapod was found to not only render the effective dispersion of CdSe tetrapods in the P3HT matrix, but also facilitate the efficient electronic interaction between these two semiconducting constituents. The successful anchoring of P3HT chains onto CdSe tetrapods was substantiated through Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy measurements. Moreover, the absorption and photoluminescence studies further corroborated the intimate tethering between P3HT and CdSe tetrapods. The effect of the type of bifunctional ligands (i.e., aryl vs. aliphatic ligands) and the size of tetrapods on the device performance of hybrid organic-inorganic solar cells was also scrutinized. Interestingly, P3HT-CdSe tetrapod nanocomposites produced via the use of an aryl bifunctional ligand (i.e., 4-azidobenzoic acid) exhibited an improved photovoltaic performance compared to that synthesized with their aliphatic ligand counterpart (i.e., 5-bromovaleric acid). Clearly, the optimal size of CdSe tetrapods ensuring the effective charge transport in conjunction with the good dispersion of CdSe tetrapods rendered an improved device performance. We envision that the click-reaction strategy enabled by

Advanced oxidation chemistry of paracetamol. UV/H(2)O(2)-induced hydroxylation/degradation pathways and (15)N-aided inventory of nitrogenous breakdown products.

PubMed

Vogna, Davide; Marotta, Raffaele; Napolitano, Alessandra; D'Ischia, Marco

2002-08-23

The advanced oxidation chemistry of the antipyretic drug paracetamol (1) with the UV/H(2)O(2) system was investigated by an integrated methodology based on (15)N-labeling and GC-MS, HPLC, and 2D (1)H, (13)C, and (15)N NMR analysis. Main degradation pathways derived from three hydroxylation steps, leading to 1,4-hydroquinone/1,4-benzoquinone, 4-acetylaminocatechol and, to a much lesser extent, 4-acetylaminoresorcine. Oxidation of the primary aromatic intermediates, viz. 4-acetylaminocatechol, 1,4-hydroquinone, 1,4-benzoquinone, and 1,2,4-benzenetriol, resulted in a series of nitrogenous and non-nitrogenous degradation products. The former included N-acetylglyoxylamide, acetylaminomalonic acid, acetylaminohydroxymalonic acid, acetylaminomaleic acid, diastereoisomeric 2-acetylamino-3-hydroxybutanedioic acids, 2-acetylaminobutenedioic acid, 3-acetylamino-4-hydroxy-2-pentenedioic acid, and 2,4-dihydroxy-3-acetylamino-2-pentenedioic acid, as well as two muconic and hydroxymuconic acid derivatives. (15)N NMR spectra revealed the accumulation since the early stages of substantial amounts of acetamide and oxalic acid monoamide. These results provide the first insight into the advanced oxidation chemistry of a 4-aminophenol derivative by the UV/H(2)O(2) system, and highlight the investigative potential of integrated GC-MS/NMR methodologies based on (15)N-labeling to track degradation pathways of nitrogenous species.

The Hydric Effect in Inorganic Nanomaterials for Nanoelectronics and Energy Applications.

PubMed

Sun, Xu; Guo, Yuqiao; Wu, Changzheng; Xie, Yi

2015-07-08

Protons, as one of the world's smallest ions, are able to trigger the charge effect without obvious lattice expansion inside inorganic materials, offering a unique and important test-bed for controlling their diverse functionalities. Arising from the high chemical reactivity of hydrogen (easily losing an electron) with various main group anions (easily accepting a proton), the hydric effect provides a convenient and environmentally benign route to bring about fascinating new physicochemical properties, as well as to create new inorganic structures based on the "old lattice" without dramatically destroying the pristine structure, covering most inorganic materials. Moreover, hydrogen atoms tend to bond with anions or to produce intrinsic defects, both of which are expected to inject extra electrons into lattice framework, promising advances in control of bandgap, spin behavior, and carrier concentration, which determine functionality for wide applications. In this review article, recently developed effective hydric strategies are highlighted, which include the conventional hydric reaction under high temperature or room temperature, proton irradiation or hydrogen plasma treatment, and gate-electrolyte-driven adsorption or doping. The diverse physicochemical properties brought by the hydric effect via modulation of the intrinsic electronic structure are also summarized, finding wide applications in nanoelectronics, energy applications, and catalysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flow chemistry syntheses of natural products.

PubMed

Pastre, Julio C; Browne, Duncan L; Ley, Steven V

2013-12-07

The development and application of continuous flow chemistry methods for synthesis is a rapidly growing area of research. In particular, natural products provide demanding challenges to this developing technology. This review highlights successes in the area with an emphasis on new opportunities and technological advances.

Development of a chlorine chemistry module for the Master Chemical Mechanism

NASA Astrophysics Data System (ADS)

Xue, L. K.; Saunders, S. M.; Wang, T.; Gao, R.; Wang, X. F.; Zhang, Q. Z.; Wang, W. X.

2015-06-01

The chlorine atom (Cl·) has a high potential to perturb atmospheric photochemistry by oxidizing volatile organic compounds (VOCs), but the exact role it plays in the polluted troposphere remains unclear. The Master Chemical Mechanism (MCM) is a near explicit mechanism that has been widely applied in the atmospheric chemistry research. While it addresses comprehensively the chemistry initiated by the OH, O3 and NO3 radicals, its representation of the Cl· chemistry is incomplete as it only considers the reactions for alkanes. In this paper, we develop a more comprehensive Cl· chemistry module that can be directly incorporated within the MCM framework. A suite of 199 chemical reactions describes the Cl·-initiated degradation of alkenes, aromatics, aldehydes, ketones, alcohols, and some organic acids and nitrates, along with the inorganic chemistry involving Cl· and its precursors. To demonstrate the potential influence of the new chemistry module, it was incorporated into a MCM box model to evaluate the impacts of nitryl chloride (ClNO2), a product of nocturnal halogen activation by nitrogen oxides (NOx), on the following-day's atmospheric photochemistry. With constraints of recent observations collected at a coastal site in Hong Kong, southern China, the modeling analyses suggest that the Cl· produced from ClNO2 photolysis may substantially enhance the atmospheric oxidative capacity, VOC oxidation, and O3 formation, particularly in the early morning period. The results demonstrate the critical need for photochemical models to include more fully chlorine chemistry in order to better understand the atmospheric photochemistry in polluted environments subject to intense emissions of NOx, VOCs and chlorine-containing constituents.

Development of a chlorine chemistry module for the Master Chemical Mechanism

NASA Astrophysics Data System (ADS)

Xue, L. K.; Saunders, S. M.; Wang, T.; Gao, R.; Wang, X. F.; Zhang, Q. Z.; Wang, W. X.

2015-10-01

The chlorine atom (Cl·) has a high potential to perturb atmospheric photochemistry by oxidizing volatile organic compounds (VOCs), but the exact role it plays in the polluted troposphere remains unclear. The Master Chemical Mechanism (MCM) is a near-explicit mechanism that has been widely applied in the atmospheric chemistry research. While it addresses comprehensively the chemistry initiated by the OH, O3 and NO3 radicals, its representation of the Cl· chemistry is incomplete as it only considers the reactions for alkanes. In this paper, we develop a more comprehensive Cl· chemistry module that can be directly incorporated within the MCM framework. A suite of 205 chemical reactions describes the Cl·-initiated degradation of alkenes, aromatics, alkynes, aldehydes, ketones, alcohols, and some organic acids and nitrates, along with the inorganic chemistry involving Cl· and its precursors. To demonstrate the potential influence of the new chemistry module, it was incorporated into a MCM box model to evaluate the impacts of nitryl chloride (ClNO2), a product of nocturnal halogen activation by nitrogen oxides (NOX), on the following day's atmospheric photochemistry. With constraints of recent observations collected at a coastal site in Hong Kong, southern China, the modeling analyses suggest that the Cl· produced from ClNO2 photolysis may substantially enhance the atmospheric oxidative capacity, VOC oxidation and O3 formation, particularly in the early morning period. The results demonstrate the critical need for photochemical models to include more detailed chlorine chemistry in order to better understand the atmospheric photochemistry in polluted environments subject to intense emissions of NOX, VOCs and chlorine-containing constituents.

Impact of Enhanced Ozone Deposition and Halogen Chemistry on Tropospheric Ozone over the Northern Hemisphere.

PubMed

Sarwar, Golam; Gantt, Brett; Schwede, Donna; Foley, Kristen; Mathur, Rohit; Saiz-Lopez, Alfonso

2015-08-04

Fate of ozone in marine environments has been receiving increased attention due to the tightening of ambient air quality standards. The role of deposition and halogen chemistry is examined through incorporation of an enhanced ozone deposition algorithm and inclusion of halogen chemistry in a comprehensive atmospheric modeling system. The enhanced ozone deposition treatment accounts for the interaction of iodide in seawater with ozone and increases deposition velocities by 1 order of magnitude. Halogen chemistry includes detailed chemical reactions of organic and inorganic bromine and iodine species. Two different simulations are completed with the halogen chemistry: without and with photochemical reactions of higher iodine oxides. Enhanced deposition reduces mean summer-time surface ozone by ∼3% over marine regions in the Northern Hemisphere. Halogen chemistry without the photochemical reactions of higher iodine oxides reduces surface ozone by ∼15% whereas simulations with the photochemical reactions of higher iodine oxides indicate ozone reductions of ∼48%. The model without these processes overpredicts ozone compared to observations whereas the inclusion of these processes improves predictions. The inclusion of photochemical reactions for higher iodine oxides leads to ozone predictions that are lower than observations, underscoring the need for further refinement of the halogen emissions and chemistry scheme in the model.

Surface Conductive Glass.

ERIC Educational Resources Information Center

Tanaka, John; Suib, Steven L.

1984-01-01

Discusses the properties of surface-conducting glass and the chemical nature of surface-conducting stannic (tin) oxide. Also provides the procedures necessary for the preparation of surface-conducting stannic oxide films on glass substrates. The experiment is suitable for the advanced inorganic chemistry laboratory. (JN)

The Pythagorean Theorem and the Solid State

ERIC Educational Resources Information Center

Kelly, Brenda S.; Splittgerber, Allan G.

2005-01-01

Packing efficiency and crystal density can be calculated from basic geometric principles employing the Pythagorean theorem, if the unit-cell structure is known. The procedures illustrated have applicability in courses such as general chemistry, intermediate and advanced inorganic, materials science, and solid-state physics.

Advances in molecular quantum chemistry contained in the Q-Chem 4 program package

NASA Astrophysics Data System (ADS)

Shao, Yihan; Gan, Zhengting; Epifanovsky, Evgeny; Gilbert, Andrew T. B.; Wormit, Michael; Kussmann, Joerg; Lange, Adrian W.; Behn, Andrew; Deng, Jia; Feng, Xintian; Ghosh, Debashree; Goldey, Matthew; Horn, Paul R.; Jacobson, Leif D.; Kaliman, Ilya; Khaliullin, Rustam Z.; Kuś, Tomasz; Landau, Arie; Liu, Jie; Proynov, Emil I.; Rhee, Young Min; Richard, Ryan M.; Rohrdanz, Mary A.; Steele, Ryan P.; Sundstrom, Eric J.; Woodcock, H. Lee, III; Zimmerman, Paul M.; Zuev, Dmitry; Albrecht, Ben; Alguire, Ethan; Austin, Brian; Beran, Gregory J. O.; Bernard, Yves A.; Berquist, Eric; Brandhorst, Kai; Bravaya, Ksenia B.; Brown, Shawn T.; Casanova, David; Chang, Chun-Min; Chen, Yunqing; Chien, Siu Hung; Closser, Kristina D.; Crittenden, Deborah L.; Diedenhofen, Michael; DiStasio, Robert A., Jr.; Do, Hainam; Dutoi, Anthony D.; Edgar, Richard G.; Fatehi, Shervin; Fusti-Molnar, Laszlo; Ghysels, An; Golubeva-Zadorozhnaya, Anna; Gomes, Joseph; Hanson-Heine, Magnus W. D.; Harbach, Philipp H. P.; Hauser, Andreas W.; Hohenstein, Edward G.; Holden, Zachary C.; Jagau, Thomas-C.; Ji, Hyunjun; Kaduk, Benjamin; Khistyaev, Kirill; Kim, Jaehoon; Kim, Jihan; King, Rollin A.; Klunzinger, Phil; Kosenkov, Dmytro; Kowalczyk, Tim; Krauter, Caroline M.; Lao, Ka Un; Laurent, Adèle D.; Lawler, Keith V.; Levchenko, Sergey V.; Lin, Ching Yeh; Liu, Fenglai; Livshits, Ester; Lochan, Rohini C.; Luenser, Arne; Manohar, Prashant; Manzer, Samuel F.; Mao, Shan-Ping; Mardirossian, Narbe; Marenich, Aleksandr V.; Maurer, Simon A.; Mayhall, Nicholas J.; Neuscamman, Eric; Oana, C. Melania; Olivares-Amaya, Roberto; O'Neill, Darragh P.; Parkhill, John A.; Perrine, Trilisa M.; Peverati, Roberto; Prociuk, Alexander; Rehn, Dirk R.; Rosta, Edina; Russ, Nicholas J.; Sharada, Shaama M.; Sharma, Sandeep; Small, David W.; Sodt, Alexander; Stein, Tamar; Stück, David; Su, Yu-Chuan; Thom, Alex J. W.; Tsuchimochi, Takashi; Vanovschi, Vitalii; Vogt, Leslie; Vydrov, Oleg; Wang, Tao; Watson, Mark A.; Wenzel, Jan; White, Alec; Williams, Christopher F.; Yang, Jun; Yeganeh, Sina; Yost, Shane R.; You, Zhi-Qiang; Zhang, Igor Ying; Zhang, Xing; Zhao, Yan; Brooks, Bernard R.; Chan, Garnet K. L.; Chipman, Daniel M.; Cramer, Christopher J.; Goddard, William A., III; Gordon, Mark S.; Hehre, Warren J.; Klamt, Andreas; Schaefer, Henry F., III; Schmidt, Michael W.; Sherrill, C. David; Truhlar, Donald G.; Warshel, Arieh; Xu, Xin; Aspuru-Guzik, Alán; Baer, Roi; Bell, Alexis T.; Besley, Nicholas A.; Chai, Jeng-Da; Dreuw, Andreas; Dunietz, Barry D.; Furlani, Thomas R.; Gwaltney, Steven R.; Hsu, Chao-Ping; Jung, Yousung; Kong, Jing; Lambrecht, Daniel S.; Liang, WanZhen; Ochsenfeld, Christian; Rassolov, Vitaly A.; Slipchenko, Lyudmila V.; Subotnik, Joseph E.; Van Voorhis, Troy; Herbert, John M.; Krylov, Anna I.; Gill, Peter M. W.; Head-Gordon, Martin

2015-01-01

A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Møller-Plesset (MP2) methods for intermolecular interactions, a variety of parallel performance benchmarks, and tests of the accuracy of implicit solvation models. Some specific chemical examples include calculations on the strongly correlated Cr2 dimer, exploring zeolite-catalysed ethane dehydrogenation, energy decomposition analysis of a charged ter-molecular complex arising from glycerol photoionisation, and natural transition orbitals for a Frenkel exciton state in a nine-unit model of a self-assembling nanotube.

A Simplified Model to Predict the Effect of Increasing Atmospheric CO[subscript 2] on Carbonate Chemistry in the Ocean

ERIC Educational Resources Information Center

Bozlee, Brian J.; Janebo, Maria; Jahn, Ginger

2008-01-01

The chemistry of dissolved inorganic carbon in seawater is reviewed and used to predict the potential effect of rising levels of carbon dioxide in the atmosphere. In agreement with more detailed treatments, we find that calcium carbonate (aragonite) may become unsaturated in cold surface seawater by the year 2100 C.E., resulting in the destruction…

Recent advances in the research of inorganic nanotubes and fullerene-like nanoparticles

NASA Astrophysics Data System (ADS)

Tenne, Reshef

2014-06-01

This minireview outlines the main scientific directions in the research of inorganic nanotubes (INT) and fullerene-like (IF) nanoparticles from layered compounds, in recent years. In particular, this review describes to some detail the progress in the synthesis of new nanotubes, including those from misfit compounds; core-shell and the successful efforts to scale-up the synthesis of WS2 multiwall nanotubes. The high-temperature catalytic growth of nanotubes, via solar ablation is discussed as well. Furthermore, the doping of the IF-MoS2 nanoparticles and its influence on the physiochemical properties of the nanoparticles, including their interesting tribological properties are briefly discussed. Finally, the numerous applications of these nanoparticles as superior solid lubricants and for reinforcing variety of polymers are discussed in brief.

Understanding and Using the New Guided-Inquiry AP Chemistry Laboratory Manual

ERIC Educational Resources Information Center

Cacciatore, Kristen L.

2014-01-01

To support teaching and learning in the advanced placement (AP) chemistry laboratory, the College Board published a laboratory manual, "AP Chemistry Guided-Inquiry Experiments: Applying the Science Practices," in 2013 as part of the redesigned course. This article provides a discussion of the rationale for the existence of the manual as…

Printing, folding and assembly methods for forming 3D mesostructures in advanced materials

NASA Astrophysics Data System (ADS)

Zhang, Yihui; Zhang, Fan; Yan, Zheng; Ma, Qiang; Li, Xiuling; Huang, Yonggang; Rogers, John A.

2017-03-01

A rapidly expanding area of research in materials science involves the development of routes to complex 3D structures with feature sizes in the mesoscopic range (that is, between tens of nanometres and hundreds of micrometres). A goal is to establish methods for controlling the properties of materials systems and the function of devices constructed with them, not only through chemistry and morphology, but also through 3D architectures. The resulting systems, sometimes referred to as metamaterials, offer engineered behaviours with optical, thermal, acoustic, mechanical and electronic properties that do not occur in the natural world. Impressive advances in 3D printing techniques represent some of the most broadly recognized developments in this field, but recent successes with strategies based on concepts in origami, kirigami and deterministic assembly provide additional, unique options in 3D design and high-performance materials. In this Review, we highlight the latest progress and trends in methods for fabricating 3D mesostructures, beginning with the development of advanced material inks for nozzle-based approaches to 3D printing and new schemes for 3D optical patterning. In subsequent sections, we summarize more recent methods based on folding, rolling and mechanical assembly, including their application with materials such as designer hydrogels, monocrystalline inorganic semiconductors and graphene.

Free Radical Chemistry of Disinfection Byproducts. 3. Degradation Mechanisms of Chloronitromethane, Bromonitromethane and Dichloronitromethane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruce J. Mincher; Stephen P. Mezyk; William J. Cooper

2010-01-01

Halonitromethanes (HNMs) are byproducts formed through ozonation and chlorine/ chloramine disinfection processes in drinking waters that contain dissolved organic matter and bromide ions. These species occur at low concentration, but have been determined to have high cytotoxicity and mutagenicity and therefore may represent a human health hazard. In this study, we have investigated the chemistry involved in the mineralization of HNMs to non-hazardous inorganic products through the application of advanced oxidation and reduction processes. We have combined measured absolute reaction rate constants for the reactions of chloronitromethane, bromonitromethane and dichloronitromethane with the hydroxyl radical and the hydrated electron with amore » kinetic computer model in an attempt to elucidate the reaction pathways of these HNMs. The results are compared to measurements of stable products resulting from steady-state 60Co y-irradiations of the same compounds. The model predicted the decomposition of the parent compounds and ingrowth of chloride and bromide ions with excellent accuracy, but the prediction of the total nitrate ion concentration was slightly in error, reflecting the complexity of nitrogen oxide species reactions in irradiated solution.« less

CsI Pre-Intercalation in the Inorganic Framework for Efficient and Stable FA1-x Csx PbI3 (Cl) Perovskite Solar Cells.

PubMed

Zhou, Ning; Shen, Yiheng; Zhang, Yu; Xu, Ziqi; Zheng, Guanhaojie; Li, Liang; Chen, Qi; Zhou, Huanping

2017-06-01

Engineering the chemical composition of organic and inorganic hybrid perovskite materials is one of the most feasible methods to boost the efficiency of perovskite solar cells with improved device stability. Among the diverse hybrid perovskite family of ABX 3 , formamidinium (FA)-based mixed perovskite (e.g., FA 1- x Cs x PbI 3 ) possesses optimum bandgaps, superior optoelectronic property, as well as thermal- and photostability, which is proven to be the most promising candidate for advanced solar cell. Here, FA 0.9 Cs 0.1 PbI 3 (Cl) is implemented as the light-harvesting layer in planar devices, whereas a low temperature, two-step solution deposition method is employed for the first time in this materials system. This paper comprehensively exploits the role of Cs + in the FA 0.9 Cs 0.1 PbI 3 (Cl) perovskite that affects the precursor chemistry, film nucleation and grain growth, and defect property via pre-intercalation of CsI in the inorganic framework. In addition, the resultant FA 0.9 Cs 0.1 PbI 3 (Cl) films are demonstrated to exhibit an improved optoelectronic property with an elevated device power conversion efficiency (PCE) of 18.6%, as well as a stable phase with substantial enhancement in humidity and thermal stability, as compared to that of FAPbI 3 (Cl). The present method is able to be further extended to a more complicated (FA,MA,Cs)PbX 3 material system by delivering a PCE of 19.8%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation Of Student Learning In Thermodynamics And Implications For Instruction In Chemistry And Engineering

NASA Astrophysics Data System (ADS)

Meltzer, David E.

2007-01-01

As part of an investigation into student learning of thermodynamics, we have probed the reasoning of students enrolled in introductory and advanced courses in both physics and chemistry. A particular focus of this work has been put on the learning difficulties encountered by physics, chemistry, and engineering students enrolled in an upper-level thermal physics course that included many topics also covered in physical chemistry courses. We have explored the evolution of students' understanding as they progressed from the introductory course through more advanced courses. Through this investigation we have gained insights into students' learning difficulties in thermodynamics at various levels. Our experience in addressing these learning difficulties may provide insights into analogous pedagogical issues in upper-level courses in both engineering and chemistry which focus on the theory and applications of thermodynamics.

Preparation and Luminescence Thermochromism of Tetranuclear Copper(I)-Pyridine-Iodide Clusters

ERIC Educational Resources Information Center

Parmeggiani, Fabio; Sacchetti, Alessandro

2012-01-01

A simple and straightforward synthesis of a tetranuclear copper(I)-pyridine-iodide cluster is described as a laboratory experiment for advanced inorganic chemistry undergraduate students. The product is used to demonstrate the fascinating and visually impressive phenomenon of luminescence thermochromism: exposed to long-wave UV light, the…

21 CFR 862.1580 - Phosphorus (inorganic) test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Phosphorus (inorganic) test system. 862.1580... Systems § 862.1580 Phosphorus (inorganic) test system. (a) Identification. A phosphorus (inorganic) test system is a device intended to measure inorganic phosphorus in serum, plasma, and urine. Measurements of...

21 CFR 862.1580 - Phosphorus (inorganic) test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Phosphorus (inorganic) test system. 862.1580... Systems § 862.1580 Phosphorus (inorganic) test system. (a) Identification. A phosphorus (inorganic) test system is a device intended to measure inorganic phosphorus in serum, plasma, and urine. Measurements of...

Magnetic separation: its application in mining, waste purification, medicine, biochemistry and chemistry.

PubMed

Iranmanesh, M; Hulliger, J

2017-10-02

The use of strong magnetic field gradients and high magnetic fields generated by permanent magnets or superconducting coils has found applications in many fields such as mining, solid state chemistry, biochemistry and medical research. Lab scale or industrial implementations involve separation of macro- and nanoparticles, cells, proteins, and macromolecules down to small molecules and ions. Most promising are those attempts where the object to be separated is attached to a strong magnetic nanoparticle. Here, all kinds of specific affinity interactions are used to attach magnetic carrier particles to mainly objects of biological interest. Other attempts use a strong paramagnetic suspension for the separation of purely diamagnetic objects, such as bio-macromolecules or heavy metals. The application of magnetic separation to superconducting inorganic phases is of particular interest in combination with ceramic combinatorial chemistry to generate a library of e.g. cuprate superconductors.

Inorganic Crystal Structure Database (ICSD) and Standardized Data and Crystal Chemical Characterization of Inorganic Structure Types (TYPIX)—Two Tools for Inorganic Chemists and Crystallographers

PubMed Central

Fluck, Ekkehard

1996-01-01

The two databases ICSD and TYPIX are described. ICSD is a comprehensive compilation of crystal structure data of inorganic compounds (about 39 000 entries). TYPIX contains 3600 critically evaluated data sets representative of structure types formed by inorganic compounds. PMID:27805158

Research advances in polymer emulsion based on "core-shell" structure particle design.

PubMed

Ma, Jian-zhong; Liu, Yi-hong; Bao, Yan; Liu, Jun-li; Zhang, Jing

2013-09-01

In recent years, quite many studies on polymer emulsions with unique core-shell structure have emerged at the frontier between material chemistry and many other fields because of their singular morphology, properties and wide range of potential applications. Organic substance as a coating material onto either inorganic or organic internal core materials promises an unparalleled opportunity for enhancement of final functions through rational designs. This contribution provides a brief overview of recent progress in the synthesis, characterization, and applications of both inorganic-organic and organic-organic polymer emulsions with core-shell structure. In addition, future research trends in polymer composites with core-shell structure are also discussed in this review. Copyright © 2013 Elsevier B.V. All rights reserved.

PATHWAY OF INORGANIC ARSENIC METABOLISM

EPA Science Inventory

A remarkable aspect of the metabolism of inorganic arsenic in humans is its conversion to methylated metabolites. These metabolites account for most of the arsenic found in urine after exposure to inorganic arsenic. At least some of the adverse health effects attributed to inor...

Materials Chemistry and Performance of Silicone-Based Replicating Compounds.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brumbach, Michael T.; Mirabal, Alex James; Kalan, Michael

Replicating compounds are used to cast reproductions of surface features on a variety of materials. Replicas allow for quantitative measurements and recordkeeping on parts that may otherwise be difficult to measure or maintain. In this study, the chemistry and replicating capability of several replicating compounds was investigated. Additionally, the residue remaining on material surfaces upon removal of replicas was quantified. Cleaning practices were tested for several different replicating compounds. For all replicating compounds investigated, a thin silicone residue was left by the replica. For some compounds, additional inorganic species could be identified in the residue. Simple solvent cleaning could removemore » some residue.« less

Direct-push geochemical profiling for assessment of inorganic chemical heterogeneity in aquifers

USGS Publications Warehouse

Schulmeister, M.K.; Healey, J.M.; Butler, J.J.; McCall, G.W.

2004-01-01

Discrete-depth sampling of inorganic groundwater chemistry is essential for a variety of site characterization activities. Although the mobility and rapid sampling capabilities of direct-push techniques have led to their widespread use for evaluating the distribution of organic contaminants, complementary methods for the characterization of spatial variations in geochemical conditions have not been developed. In this study, a direct-push-based approach for high-resolution inorganic chemical profiling was developed at a site where sharp chemical contrasts and iron-reducing conditions had previously been observed. Existing multilevel samplers (MLSs) that span a fining-upward alluvial sequence were used for comparison with the direct-push profiling. Chemical profiles obtained with a conventional direct-push exposed-screen sampler differed from those obtained with an adjacent MLS because of sampler reactivity and mixing with water from previous sampling levels. The sampler was modified by replacing steel sampling components with stainless-steel and heat-treated parts, and adding an adapter that prevents mixing. Profiles obtained with the modified approach were in excellent agreement with those obtained from an adjacent MLS for all constituents and parameters monitored (Cl, NO3, Fe, Mn, DO, ORP, specific conductance and pH). Interpretations of site redox conditions based on field-measured parameters were supported by laboratory analysis of dissolved Fe. The discrete-depth capability of this approach allows inorganic chemical variations to be described at a level of detail that has rarely been possible. When combined with the mobility afforded by direct-push rigs and on-site methods of chemical analysis, the new approach is well suited for a variety of interactive site-characterization endeavors. ?? 2003 Elsevier B.V. All rights reserved.

Inorganic aerosols responses to emission changes in Yangtze River Delta, China.

PubMed

Dong, Xinyi; Li, Juan; Fu, Joshua S; Gao, Yang; Huang, Kan; Zhuang, Guoshun

2014-05-15

The new Chinese National Ambient Air Quality standards (CH-NAAQS) published on Feb. 29th, 2012 listed PM2.5 as criteria pollutant for the very first time. In order to probe into PM2.5 pollution over Yangtze River Delta, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Total PM2.5 concentration over YRD was found to have strong seasonal variation with higher values in winter months (up to 89.9 μg/m(3) in January) and lower values in summer months (down to 28.8 μg/m(3) in July). Inorganic aerosols were found to have substantial contribution to PM2.5 over YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3(-)) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3(-) concentration throughout the year. In winter, NO3(-) was found to increase under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4(+)) and sulfate (SO4(2-)), while other seasons showed decrease response of NO3(-). Sensitivity responses of NO3(-) under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3(-) formation was actually more sensitive to VOC than NOx due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols. Copyright © 2014 Elsevier B.V. All rights reserved.

Creation of Medicinal Chemistry Learning Communities Through Enhanced Technology and Interdisciplinary Collaboration

PubMed Central

Roche, Victoria

2012-01-01

Objectives. To build an integrated medicinal chemistry learning community of campus and distance pharmacy students though the use of innovative technology and interdisciplinary teaching. Design. Mechanisms were implemented to bring distance students into campus-based medicinal chemistry classrooms in real time, stimulate interaction between instructors and various student cohorts, and promote group work during class. Also, pharmacy clinician colleagues were recruited to contribute to the teaching of the 3 medicinal chemistry courses. Assessment. Student perceptions on the value of technology to build community and advance learning were gleaned from course evaluations, in class feedback, and conversations with class officers and student groups. Responses on a survey of second-year students confirmed the benefits of interdisciplinary content integration on engagement and awareness of the connection between drug chemistry and pharmacy practice. A survey of clinician colleagues who contributed to teaching the 3 medicinal chemistry courses found their views were similar to those of students. Conclusions. The purposeful use of technology united learners, fostered communication, and advanced content comprehension in 3 medicinal chemistry courses taught to campus and distance students. Teaching collaboration with pharmacy clinicians enhanced learner interest in course content and provided insight into the integrated nature of the profession of pharmacy. PMID:23129857

Creation of medicinal chemistry learning communities through enhanced technology and interdisciplinary collaboration.

PubMed

Henriksen, Brian; Roche, Victoria

2012-10-12

Objectives. To build an integrated medicinal chemistry learning community of campus and distance pharmacy students though the use of innovative technology and interdisciplinary teaching.Design. Mechanisms were implemented to bring distance students into campus-based medicinal chemistry classrooms in real time, stimulate interaction between instructors and various student cohorts, and promote group work during class. Also, pharmacy clinician colleagues were recruited to contribute to the teaching of the 3 medicinal chemistry courses.Assessment. Student perceptions on the value of technology to build community and advance learning were gleaned from course evaluations, in class feedback, and conversations with class officers and student groups. Responses on a survey of second-year students confirmed the benefits of interdisciplinary content integration on engagement and awareness of the connection between drug chemistry and pharmacy practice. A survey of clinician colleagues who contributed to teaching the 3 medicinal chemistry courses found their views were similar to those of students.Conclusions. The purposeful use of technology united learners, fostered communication, and advanced content comprehension in 3 medicinal chemistry courses taught to campus and distance students. Teaching collaboration with pharmacy clinicians enhanced learner interest in course content and provided insight into the integrated nature of the profession of pharmacy.

Medicinal chemistry for 2020

PubMed Central

Satyanarayanajois, Seetharama D; Hill, Ronald A

2011-01-01

Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five main angles to be addressed are: protein–protein interactions; peptides and peptidomimetics; molecular diversity and pharmacological space; molecular pharmacodynamics (significance, potential and challenges); and early-stage clinical efficacy and safety. We then consider, in light of these, the future of medicinal chemistry and the educational preparation that will be required for future medicinal chemists. PMID:22004084

Organic-Inorganic Composites Toward Biomaterial Application.

PubMed

Miyazaki, Toshiki; Sugawara-Narutaki, Ayae; Ohtsuki, Chikara

2015-01-01

Bioactive ceramics are known to exhibit specific biological affinities and are able to show direct integration with surrounding bone when implanted in bony defects. However, their inadequate mechanical properties, such as low fracture toughness and high Young's modulus in comparison to natural bone, limit their clinical application. Bone is a kind of organic-inorganic composite where apatite nanocrystals are precipitated onto collagen fibre networks. Thus, one way to address these problems is to mimic the natural composition of bone by using bioactive ceramics via material designs based on organic-inorganic composites. In this chapter, the current research on the development of the various organic-inorganic composites designed for biomaterial applications has been reviewed. Various compounds such as calcium phosphate, calcium sulphate and calcium carbonate can be used for the inorganic phases to design composites with the desired mechanical and biological properties of bone. Not only classical mechanical mixing but also coating of the inorganic phase in aqueous conditions is available for the fabrication of such composites. Organic modifications using various polymers enable the control of the crystalline structure of the calcium carbonate in the composites. These approaches on the fabrication of organic-inorganic composites provide important options for biomedical materials with novel functions. © 2015 S. Karger AG, Basel.

Comptox Chemistry Dashboard: Web-Based Data Integration Hub for Environmental Chemistry and Toxicology Data (ACS Fall meeting 4 of 12)

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) Computational Toxicology Program integrate advances in biology, chemistry, exposure and computer science to help prioritize chemicals for further research based on potential human health risks. This work involves computational and da...

All-Inorganic Perovskite Solar Cells.

PubMed

Liang, Jia; Wang, Caixing; Wang, Yanrong; Xu, Zhaoran; Lu, Zhipeng; Ma, Yue; Zhu, Hongfei; Hu, Yi; Xiao, Chengcan; Yi, Xu; Zhu, Guoyin; Lv, Hongling; Ma, Lianbo; Chen, Tao; Tie, Zuoxiu; Jin, Zhong; Liu, Jie

2016-12-14

The research field on perovskite solar cells (PSCs) is seeing frequent record breaking in the power conversion efficiency (PCE). However, organic-inorganic hybrid halide perovskites and organic additives in common hole-transport materials (HTMs) exhibit poor stability against moisture and heat. Here we report the successful fabrication of all-inorganic PSCs without any labile or expensive organic components. The entire fabrication process can be operated in ambient environment without humidity control (e.g., a glovebox). Even without encapsulation, the all-inorganic PSCs present no performance degradation in humid air (90-95% relative humidity, 25 °C) for over 3 months (2640 h) and can endure extreme temperatures (100 and -22 °C). Moreover, by elimination of expensive HTMs and noble-metal electrodes, the cost was significantly reduced. The highest PCE of the first-generation all-inorganic PSCs reached 6.7%. This study opens the door for next-generation PSCs with long-term stability under harsh conditions, making practical application of PSCs a real possibility.

Inorganic-based proton conductive composite membranes for elevated temperature and reduced relative humidity PEM fuel cells

NASA Astrophysics Data System (ADS)

Wang, Chunmei

Proton exchange membrane (PEM) fuel cells are regarded as highly promising energy conversion systems for future transportation and stationary power generation and have been under intensive investigations for the last decade. Unfortunately, cutting edge PEM fuel cell design and components still do not allow economically commercial implementation of this technology. The main obstacles are high cost of proton conductive membranes, low-proton conductivity at low relative humidity (RH), and dehydration and degradation of polymer membranes at high temperatures. The objective of this study was to develop a systematic approach to design a high proton conductive composite membrane that can provide a conductivity of approximately 100 mS cm-1 under hot and dry conditions (120°C and 50% RH). The approach was based on fundamental and experimental studies of the proton conductivity of inorganic additives and composite membranes. We synthesized and investigated a variety of organic-inorganic Nafion-based composite membranes. In particular, we analyzed their fundamental properties, which included thermal stability, morphology, the interaction between inorganic network and Nafion clusters, and the effect of inorganic phase on the membrane conductivity. A wide range of inorganic materials was studied in advance in order to select the proton conductive inorganic additives for composite membranes. We developed a conductivity measurement method, with which the proton conductivity characteristics of solid acid materials, zirconium phosphates, sulfated zirconia (S-ZrO2), phosphosilicate gels, and Santa Barbara Amorphous silica (SBA-15) were discussed in detail. Composite membranes containing Nafion and different amounts of functionalized inorganic additives (sulfated inorganics such as S-ZrO2, SBA-15, Mobil Composition of Matter MCM-41, and S-SiO2, and phosphonated inorganic P-SiO2) were synthesized with different methods. We incorporated inorganic particles within Nafion clusters

Environmental chemistry at vapor/water interfaces: insights from vibrational sum frequency generation spectroscopy.

PubMed

Jubb, Aaron M; Hua, Wei; Allen, Heather C

2012-01-01

The chemistry that occurs at surfaces has been an intense area of study for many years owing to its complexity and importance in describing a wide range of physical phenomena. The vapor/water interface is particularly interesting from an environmental chemistry perspective as this surface plays host to a wide range of chemistries that influence atmospheric and geochemical interactions. The application of vibrational sum frequency generation (VSFG), an inherently surface-specific, even-order nonlinear optical spectroscopy, enables the direct interrogation of various vapor/aqueous interfaces to elucidate the behavior and reaction of chemical species within the surface regime. In this review we discuss the application of VSFG to the study of a variety of atmospherically important systems at the vapor/aqueous interface. Chemical systems presented include inorganic ionic solutions prevalent in aqueous marine aerosols, small molecular solutes, and long-chain fatty acids relevant to fat-coated aerosols. The ability of VSFG to probe both the organization and reactions that may occur for these systems is highlighted. A future perspective toward the application of VSFG to the study of environmental interfaces is also provided.

Affordances of instrumentation in general chemistry laboratories

NASA Astrophysics Data System (ADS)

Sherman, Kristin Mary Daniels

The purpose of this study is to find out what students in the first chemistry course at the undergraduate level (general chemistry for science majors) know about the affordances of instrumentation used in the general chemistry laboratory and how their knowledge develops over time. Overall, students see the PASCO(TM) system as a useful and accurate measuring tool for general chemistry labs. They see the probeware as easy to use, portable, and able to interact with computers. Students find that the PASCO(TM) probeware system is useful in their general chemistry labs, more advanced chemistry labs, and in other science classes, and can be used in a variety of labs done in general chemistry. Students learn the affordances of the probeware through the lab manual, the laboratory teaching assistant, by trial and error, and from each other. The use of probeware systems provides lab instructors the opportunity to focus on the concepts illustrated by experiments and the opportunity to spend time discussing the results. In order to teach effectively, the instructor must know the correct name of the components involved, how to assemble and disassemble it correctly, how to troubleshoot the software, and must be able to replace broken or missing components quickly. The use of podcasts or Web-based videos should increase student understanding of affordances of the probeware.

A One-Pot Self-Assembly Reaction to Prepare a Supramolecular Palladium(II) Cyclometalated Complex: An Undergraduate Organometallic Laboratory Experiment

ERIC Educational Resources Information Center

Fernandez, Alberto; Lopez-Torres, Margarita; Fernandez, Jesus J.; Vazquez-Garcia, Digna; Vila, Jose M.

2012-01-01

A laboratory experiment for students in advanced inorganic chemistry is described. Students prepare palladium(II) cyclometalated complexes. A terdentate [C,N,O] Schiff base ligand is doubly deprotonated upon reaction with palladium(II) acetate in a self-assembly process to give a palladacycle with a characteristic tetranuclear structure. This…

Infrared Spectroscopic Analysis of Linkage Isomerism in Metal-Thiocyanate Complexes

ERIC Educational Resources Information Center

Baer, Carl; Pike, Jay

2010-01-01

We developed an experiment suitable for an advanced inorganic chemistry laboratory that utilizes a cooperative learning environment, which allows students to develop an empirical method of determining the bonding mode of a series of unknown metal-thiocyanate complexes. Students synthesize the metal-thiocyanate complexes and obtain the FT-IR…

Digital biology and chemistry.

PubMed

Witters, Daan; Sun, Bing; Begolo, Stefano; Rodriguez-Manzano, Jesus; Robles, Whitney; Ismagilov, Rustem F

2014-09-07

This account examines developments in "digital" biology and chemistry within the context of microfluidics, from a personal perspective. Using microfluidics as a frame of reference, we identify two areas of research within digital biology and chemistry that are of special interest: (i) the study of systems that switch between discrete states in response to changes in chemical concentration of signals, and (ii) the study of single biological entities such as molecules or cells. In particular, microfluidics accelerates analysis of switching systems (i.e., those that exhibit a sharp change in output over a narrow range of input) by enabling monitoring of multiple reactions in parallel over a range of concentrations of signals. Conversely, such switching systems can be used to create new kinds of microfluidic detection systems that provide "analog-to-digital" signal conversion and logic. Microfluidic compartmentalization technologies for studying and isolating single entities can be used to reconstruct and understand cellular processes, study interactions between single biological entities, and examine the intrinsic heterogeneity of populations of molecules, cells, or organisms. Furthermore, compartmentalization of single cells or molecules in "digital" microfluidic experiments can induce switching in a range of reaction systems to enable sensitive detection of cells or biomolecules, such as with digital ELISA or digital PCR. This "digitizing" offers advantages in terms of robustness, assay design, and simplicity because quantitative information can be obtained with qualitative measurements. While digital formats have been shown to improve the robustness of existing chemistries, we anticipate that in the future they will enable new chemistries to be used for quantitative measurements, and that digital biology and chemistry will continue to provide further opportunities for measuring biomolecules, understanding natural systems more deeply, and advancing molecular and

Introducing Quantum Mechanics into General Chemistry

NASA Astrophysics Data System (ADS)

Popkowski, Iwona; Bascal, Hafed

2008-10-01

Periodicity has long been recognized as the tool that chemists can use to bring some order to investigating the chemistry of more than one hundred elements. Such studies provide useful tools for understanding a wide array of chemical principles. The advances in computational chemistry make it possible to study and teach such trends with hands on approach. In this study we utilize recently acquired software Spartan Pro to illustrate theoretical measurements of bond length, bond angle and dipole as compared to experimental data. We constructed a matrix of values obtained from the theoretical calculations and obtained trends in bond length, bond angle and dipoles for the several periodic groups.

Nanoscale patterning controls inorganic-membrane interface structure

NASA Astrophysics Data System (ADS)

Almquist, Benjamin D.; Verma, Piyush; Cai, Wei; Melosh, Nicholas A.

2011-02-01

The ability to non-destructively integrate inorganic structures into or through biological membranes is essential to realizing full bio-inorganic integration, including arrayed on-chip patch-clamps, drug delivery, and biosensors. Here we explore the role of nanoscale patterning on the strength of biomembrane-inorganic interfaces. AFM measurements show that inorganic probes functionalized with hydrophobic bands with thicknesses complimentary to the hydrophobic lipid bilayer core exhibit strong attachment in the bilayer. As hydrophobic band thickness increases to 2-3 times the bilayer core the interfacial strength decreases, comparable to homogeneously hydrophobic probes. Analytical calculations and molecular dynamics simulations predict a transition between a `fused' interface and a `T-junction' that matches the experimental results, showing lipid disorder and defect formation for thicker bands. These results show that matching biological length scales leads to more intimate bio-inorganic junctions, enabling rational design of non-destructive membrane interfaces.The ability to non-destructively integrate inorganic structures into or through biological membranes is essential to realizing full bio-inorganic integration, including arrayed on-chip patch-clamps, drug delivery, and biosensors. Here we explore the role of nanoscale patterning on the strength of biomembrane-inorganic interfaces. AFM measurements show that inorganic probes functionalized with hydrophobic bands with thicknesses complimentary to the hydrophobic lipid bilayer core exhibit strong attachment in the bilayer. As hydrophobic band thickness increases to 2-3 times the bilayer core the interfacial strength decreases, comparable to homogeneously hydrophobic probes. Analytical calculations and molecular dynamics simulations predict a transition between a `fused' interface and a `T-junction' that matches the experimental results, showing lipid disorder and defect formation for thicker bands. These results

A Review of Organic and Inorganic Biomaterials for Neural Interfaces

PubMed Central

Fattahi, Pouria; Yang, Guang; Kim, Gloria

2015-01-01

Recent advances in nanotechnology have generated wide interest in applying nanomaterials for neural prostheses. An ideal neural interface should create seamless integration into the nervous system and performs reliably for long periods of time. As a result, many nanoscale materials not originally developed for neural interfaces become attractive candidates to detect neural signals and stimulate neurons. In this comprehensive review, an overview of state-of-the-art microelectrode technologies provided first, with focus on the material properties of these microdevices. The advancements in electro active nanomaterials are then reviewed, including conducting polymers, carbon nanotubes, graphene, silicon nanowires, and hybrid organic-inorganic nanomaterials, for neural recording, stimulation, and growth. Finally, technical and scientific challenges are discussed regarding biocompatibility, mechanical mismatch, and electrical properties faced by these nanomaterials for the development of long-lasting functional neural interfaces. PMID:24677434

A review of organic and inorganic biomaterials for neural interfaces.

PubMed

Fattahi, Pouria; Yang, Guang; Kim, Gloria; Abidian, Mohammad Reza

2014-03-26

Recent advances in nanotechnology have generated wide interest in applying nanomaterials for neural prostheses. An ideal neural interface should create seamless integration into the nervous system and performs reliably for long periods of time. As a result, many nanoscale materials not originally developed for neural interfaces become attractive candidates to detect neural signals and stimulate neurons. In this comprehensive review, an overview of state-of-the-art microelectrode technologies provided fi rst, with focus on the material properties of these microdevices. The advancements in electro active nanomaterials are then reviewed, including conducting polymers, carbon nanotubes, graphene, silicon nanowires, and hybrid organic-inorganic nanomaterials, for neural recording, stimulation, and growth. Finally, technical and scientific challenges are discussed regarding biocompatibility, mechanical mismatch, and electrical properties faced by these nanomaterials for the development of long-lasting functional neural interfaces.

[Application of simultaneous determination of inorganic ionic species by advanced ion chromatography for water quality monitoring of river water and wastewater].

PubMed

Nakatani, Nobutake; Kozaki, Daisuke; Tanaka, Kazuhiko

2012-04-01

In this study, our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions (SO4(2-), Cl(-) and NO3(-)) and cations (Na+, NH4+, K+, Mg2+, and Ca2+), nutrients (phosphate and silicate) and hydrogen ion/alkalinity are summarized first. Then, the applications using these methods for monitoring environmental water quality are also presented. For the determination of common anions and cations with nutrients, the separation was successfully performed by a polymethacrylate-based weakly acidic cation-exchange column of TSKgel Super IC-A/C (Tosoh, 150 mm x 6.0 mm i. d.) and a mixture solution of 100 mmol/L ascorbic acid and 4 mmol/L 18-crown-6 as acidic eluent with dual detection of conductivity and spectrophotometry. For the determination of hydrogen ion/alkalinity, the separation was conducted by TSKgel ODS-100Z column (Tosoh, 150 mm x 4.5 mm i. d.) modified with lithium dodecylsulfate and an eluent of 40 mmol/L LiCl/0.1 mmol/L lithium dodecylsulfate/0.05 mmol/L H2SO4 with conductivity detector. The differences of ion concentration between untreated and treated wastewater showed the variation of ionic species during biological treatment process in a sewage treatment plant. Occurrence and distribution of water-quality conditions were related to the bioavailability and human activity in watershed. From these results, our advanced ion chromatographic methods have contributed significantly for water quality monitoring of environmental waters.

Visualizing Chemistry: The Progess and Promise of Advanced Chemical Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Committee on Revealing Chemistry Through Advanced Chemical Imaging

2006-09-01

The field of chemical imaging can provide detailed structural, functional, and applicable information about chemistry and chemical engineering phenomena that have enormous impacts on medicine, materials, and technology. In recognizing the potential for more research development in the field of chemical imaging, the National Academies was asked by the National Science Foundation, Department of Energy, U.S. Army, and National Cancer Institute to complete a study that would review the current state of molecular imaging technology, point to promising future developments and their applications, and suggest a research and educational agenda to enable breakthrough improvements in the ability to image molecularmore » processes simultaneously in multiple physical dimensions as well as time. The study resulted in a consensus report that provides guidance for a focused research and development program in chemical imaging and identifies research needs and possible applications of imaging technologies that can provide the breakthrough knowledge in chemistry, materials science, biology, and engineering for which we should strive. Public release of this report is expected in early October.« less

Chemistry and Biology of the Caged Garcinia Xanthones

PubMed Central

Chantarasriwong, Oraphin; Batova, Ayse; Chavasiri, Warinthorn

2011-01-01

Natural products have been a great source of many small molecule drugs for various diseases. In spite of recent advances in biochemical engineering and fermentation technologies that allow us to explore microorganisms and the marine environment as alternative sources of drugs, more than 70% of the current small molecule therapeutics derive their structures from plants used in traditional medicine. Natural-product-based drug discovery relies heavily on advances made in the sciences of biology and chemistry. Whereas biology aims to investigate the mode of action of a natural product, chemistry aims to overcome challenges related to its supply, bioactivity, and target selectivity. This review summarizes the explorations of the caged Garcinia xanthones, a family of plant metabolites that possess a unique chemical structure, potent bioactivities, and a promising pharmacology for drug design and development. PMID:20648491

A Review on Recent Patents and Applications of Inorganic Material Binding Peptides.

PubMed

Thota, Veeranjaneyulu; Perry, Carole C

2017-01-01

Although the popularity of using combinatorial display techniques for recognising unique peptides having high affinity for inorganic (nano) particles has grown rapidly, there are no systematic reviews showcasing current developments or patents on binding peptides specific to these materials. In this review, we summarize and discuss recent progress in patents on material binding peptides specifically exploring inorganic nano surfaces such as metals, metal oxides, minerals, carbonbased materials, polymer based materials, magnetic materials and semiconductors. We consider both the peptide display strategies used and the exploitation of the identified peptides in the generation of advanced nanomaterials. In order to get a clear picture on the number of patents and literature present to date relevant to inorganic material binding biomolecules and their applications, a thorough online search was conducted using national and worldwide databases. The literature search include standard bibliographic databases while patents included EPO Espacenet, WIPO patent scope, USPTO, Google patent search, Patent lens, etc. along with commercial databases such as Derwent and Patbase. Both English and American spellings were included in the searches. The initial number of patents found related to material binders were 981. After reading and excluding irrelevant patents such as organic binding peptides, works published before 2001, repeated patents, documents not in English etc., 51 highly relevant patents published from 2001 onwards were selected and analysed. These patents were further separated into six categories based on their target inorganic material and combinatorial library used. They include relevant patents on metal, metal oxide or combination binding peptides (19), magnetic and semiconductor binding peptides (8), carbon based (3), mineral (5), polymer (8) and other binders (9). Further, how these material specific binders have been used to synthesize simple to complex bio- or

Inorganic Chlorine Partitioning in the Summer Lower Stratosphere: Modeled and Measured [ClONO2/HCl] During POLARIS

NASA Technical Reports Server (NTRS)

Voss, P. B.; Stimpfle, R. M.; Cohen, R. C.; Hanisco, T. F.; Bonne, G. P.; Perkins, K. K.; Lanzendorf, E. J.; Anderson, J. G.; Salawitch, R. J.

2001-01-01

We examine inorganic chlorine (Cly) partitioning in the summer lower stratosphere using in situ ER-2 aircraft observations made during the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) campaign. New steady state and numerical models estimate [ClONO2]/[HCl] using currently accepted photochemistry. These models are tightly constrained by observations with OH (parameterized as a function of solar zenith angle) substituting for modeled HO2 chemistry. We find that inorganic chlorine photochemistry alone overestimates observed [ClONO2]/[HCl] by approximately 55-60% at mid and high latitudes. On the basis of POLARIS studies of the inorganic chlorine budget, [ClO]/[ClONO2], and an intercomparison with balloon observations, the most direct explanation for the model-measurement discrepancy in Cly partitioning is an error in the reactions, rate constants, and measured species concentrations linking HCl and ClO (simulated [ClO]/[HCl] too high) in combination with a possible systematic error in the ER-2 ClONO2 measurement (too low). The high precision of our simulation (+/-15% 1-sigma for [ClONO2]/[HCl], which is compared with observations) increases confidence in the observations, photolysis calculations, and laboratory rate constants. These results, along with other findings, should lead to improvements in both the accuracy and precision of stratospheric photochemical models.

Straightforward Preparation Method for Complexes Bearing a Bidentate N-Heterocyclic Carbene to Introduce Undergraduate Students to Research Methodology

ERIC Educational Resources Information Center

Fernández, Alberto; López-Torres, Margarita; Fernández, Jesús J.; Vázquez-García, Digna; Marcos, Ismael

2017-01-01

A laboratory experiment for students in advanced inorganic chemistry is described. In this experiment, students prepare two metal complexes with a potentially bidentate-carbene ligand. The complexes are synthesized by reaction of a bisimidazolium salt with silver(I) oxide or palladium(II) acetate. Silver and palladium complexes are binuclear and…

Inorganic nanoparticles for transfection of mammalian cells and removal of viruses from aqueous solutions.

PubMed

Link, Nils; Brunner, Tobias J; Dreesen, Imke A J; Stark, Wendelin J; Fussenegger, Martin

2007-12-01

Owing to their small size, synthetic nanoparticles show unprecedented biophysical and biochemical properties which may foster novel advances in life-science research. Using flame-spray synthesis technology we have produced non-coated aluminum-, calcium-, cerium-, and zirconium-derived inorganic metal oxide nanoparticles which not only exhibit high affinity for nucleic acids, but can sequester such compounds from aqueous solution. This non-covalent DNA-binding capacity was successfully used to transiently transfect a variety of mammalian cells including human, reaching transfection efficiencies which compared favorably with classic calcium phosphate precipitation (CaP) procedures and lipofection. In this straightforward protocol, transfection was enabled by simply mixing nanoparticles with DNA in solution prior to addition to the target cell population. Transiently transfected cells showed higher production levels of the human secreted glycoprotein SEAP compared to isogenic populations transfected with established technologies. Inorganic metal oxide nanoparticles also showed a high binding capacity to human-pathogenic viruses including adenovirus, adeno-associated virus and human immunodeficiency virus type 1 and were able to clear these pathogens from aqueous solutions. The DNA transfection and viral clearance capacities of inorganic metal oxide nanoparticles may provide cost-effective biopharmaceutical manufacturing and water treatment in developing countries.

Preparing, Characterizing, and Investigating Luminescent Properties of a Series of Long-Lasting Phosphors in a SrO-Al[subscript 2]O[subscript 3] System: An Integrated and Inquiry-Based Experiment in Solid State Chemistry for the Undergraduate Laboratory

ERIC Educational Resources Information Center

Ma, Yan-Zi; Jia, Li; Ma, Kai-Guo; Wang, Hai-Hong; Jing, Xi-Ping

2017-01-01

An integrated and inquiry-based experiment on solid state chemistry is applied to an inorganic chemistry lab course to provide insight into the characteristics of the solid phase reaction. In this experiment, students have the opportunity to synthesize long-lasting phosphors with formula xSrO·yAl[subscript 2]O[subscript 3]:Eu[superscript 2+],…

Inorganic nanostructure-organic polymer heterostructures useful for thermoelectric devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

See, Kevin C.; Urban, Jeffrey J.; Segalman, Rachel A.

The present invention provides for an inorganic nanostructure-organic polymer heterostructure, useful as a thermoelectric composite material, comprising (a) an inorganic nanostructure, and (b) an electrically conductive organic polymer disposed on the inorganic nanostructure. Both the inorganic nanostructure and the electrically conductive organic polymer are solution-processable.

Fabricating porous materials using interpenetrating inorganic-organic composite gels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seo, Dong-Kyun; Volosin, Alex

Porous materials are fabricated using interpenetrating inorganic-organic composite gels. A mixture or precursor solution including an inorganic gel precursor, an organic polymer gel precursor, and a solvent is treated to form an inorganic wet gel including the organic polymer gel precursor and the solvent. The inorganic wet gel is then treated to form a composite wet gel including an organic polymer network in the body of the inorganic wet gel, producing an interpenetrating inorganic-organic composite gel. The composite wet gel is dried to form a composite material including the organic polymer network and an inorganic network component. The composite materialmore » can be treated further to form a porous composite material, a porous polymer or polymer composite, a porous metal oxide, and other porous materials.« less

Interactions between Snow Chemistry, Mercury Inputs and Microbial Population Dynamics in an Arctic Snowpack

PubMed Central

Larose, Catherine; Prestat, Emmanuel; Cecillon, Sébastien; Berger, Sibel; Malandain, Cédric; Lyon, Delina; Ferrari, Christophe; Schneider, Dominique; Dommergue, Aurélien; Vogel, Timothy M.

2013-01-01

We investigated the interactions between snowpack chemistry, mercury (Hg) contamination and microbial community structure and function in Arctic snow. Snowpack chemistry (inorganic and organic ions) including mercury (Hg) speciation was studied in samples collected during a two-month field study in a high Arctic site, Svalbard, Norway (79°N). Shifts in microbial community structure were determined by using a 16S rRNA gene phylogenetic microarray. We linked snowpack and meltwater chemistry to changes in microbial community structure by using co-inertia analyses (CIA) and explored changes in community function due to Hg contamination by q-PCR quantification of Hg-resistance genes in metagenomic samples. Based on the CIA, chemical and microbial data were linked (p = 0.006) with bioavailable Hg (BioHg) and methylmercury (MeHg) contributing significantly to the ordination of samples. Mercury was shown to influence community function with increases in merA gene copy numbers at low BioHg levels. Our results show that snowpacks can be considered as dynamic habitats with microbial and chemical components responding rapidly to environmental changes. PMID:24282515

An open experimental database for exploring inorganic materials.

PubMed

Zakutayev, Andriy; Wunder, Nick; Schwarting, Marcus; Perkins, John D; White, Robert; Munch, Kristin; Tumas, William; Phillips, Caleb

2018-04-03

The use of advanced machine learning algorithms in experimental materials science is limited by the lack of sufficiently large and diverse datasets amenable to data mining. If publicly open, such data resources would also enable materials research by scientists without access to expensive experimental equipment. Here, we report on our progress towards a publicly open High Throughput Experimental Materials (HTEM) Database (htem.nrel.gov). This database currently contains 140,000 sample entries, characterized by structural (100,000), synthetic (80,000), chemical (70,000), and optoelectronic (50,000) properties of inorganic thin film materials, grouped in >4,000 sample entries across >100 materials systems; more than a half of these data are publicly available. This article shows how the HTEM database may enable scientists to explore materials by browsing web-based user interface and an application programming interface. This paper also describes a HTE approach to generating materials data, and discusses the laboratory information management system (LIMS), that underpin HTEM database. Finally, this manuscript illustrates how advanced machine learning algorithms can be adopted to materials science problems using this open data resource.

An open experimental database for exploring inorganic materials

PubMed Central

Zakutayev, Andriy; Wunder, Nick; Schwarting, Marcus; Perkins, John D.; White, Robert; Munch, Kristin; Tumas, William; Phillips, Caleb

2018-01-01

The use of advanced machine learning algorithms in experimental materials science is limited by the lack of sufficiently large and diverse datasets amenable to data mining. If publicly open, such data resources would also enable materials research by scientists without access to expensive experimental equipment. Here, we report on our progress towards a publicly open High Throughput Experimental Materials (HTEM) Database (htem.nrel.gov). This database currently contains 140,000 sample entries, characterized by structural (100,000), synthetic (80,000), chemical (70,000), and optoelectronic (50,000) properties of inorganic thin film materials, grouped in >4,000 sample entries across >100 materials systems; more than a half of these data are publicly available. This article shows how the HTEM database may enable scientists to explore materials by browsing web-based user interface and an application programming interface. This paper also describes a HTE approach to generating materials data, and discusses the laboratory information management system (LIMS), that underpin HTEM database. Finally, this manuscript illustrates how advanced machine learning algorithms can be adopted to materials science problems using this open data resource. PMID:29611842

Increasing High School Students' Chemistry Performance and Reducing Cognitive Load through an Instructional Strategy Based on the Interaction of Multiple Levels of Knowledge Representation

ERIC Educational Resources Information Center

Milenkovic´, Dus?ica D.; Segedinac, Mirjana D.; Hrin, Tamara N.

2014-01-01

The central goal of this study was to examine the extent to which a teaching approach focused on the interaction between macroscopic, submicroscopic, and symbolic levels of chemistry representations could affect high school students' performance in the field of inorganic reactions, as well as to examine how the applied instruction influences…

High-Temperature Inorganic Self-Healing Inorganic Cement Composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pyatina, Tatiana; Sugama, Toshifumi

The data files below summarize the results from various experiments testing properties of high-temperature self-healing inorganic cement composites. These properties include cement-carbon steel bond strength, Young's modulus recovery, matrix recovery strength, and compressive strength and Yonug's modulus for cement composites modified with Pozzolanic Clay additives.

High School Chemistry Students' Scientific Epistemologies and Perceptions of the Nature of Laboratory Inquiry

ERIC Educational Resources Information Center

Vhurumuku, Elaosi

2011-01-01

This quantitative study investigated the relationship between Chemistry students' scientific epistemologies and their perceptions of the nature of laboratory inquiry. Seventy-two Advanced Level Chemistry students were surveyed. The students were sampled from twelve schools in three of Zimbabwe's nine administrative provinces. Students' scientific…

Review of progress in soil inorganic carbon research

NASA Astrophysics Data System (ADS)

Bai, S. G.; Jiao, Y.; Yang, W. Z.; Gu, P.; Yang, J.; Liu, L. J.

2017-12-01

Soil inorganic carbon is one of the main carbon banks in the near-surface environment, and is the main form of soil carbon library in arid and semi-arid regions, which plays an important role in the global carbon cycle. This paper mainly focuses on the inorganic dynamic process of soil inorganic carbon in soil environment in arid and semi-arid regions, and summarized the composition and source of soil inorganic carbon, influence factors and soil carbon sequestration.

Arsenic, inorganic

Integrated Risk Information System (IRIS)

Arsenic , inorganic ; CASRN 7440 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

Placing Science into Its Human Context: Using Scientific Autobiography to Teach Chemistry

NASA Astrophysics Data System (ADS)

Carroll, Felix A.; Seeman, Jeffrey I.

2001-12-01

Scientific autobiography and biography can improve chemistry learning by helping students relate otherwise abstract concepts to important events in the lives of fellow human beings. In advanced courses, reading scientific autobiography and biography can help students see how scientific collaboration, advances in instrumentation, and major events in human lives influence the development of chemical ideas over time. In addition, studying many years of an individual's research program can demonstrate the progress of science, the connectivity of research findings, and the validity of experimental results over many decades. This paper describes the use of an autobiography of an eminent chemist in an advanced undergraduate chemistry course. This approach not only enhances the teaching of chemical concepts, but it also provides students with expanded opportunities for cooperative and self-directed learning activities.

Contributions of Analytical Chemistry to the Clinical Laboratory.

ERIC Educational Resources Information Center

Skogerboe, Kristen J.

1988-01-01

Highlights several analytical techniques that are being used in state-of-the-art clinical labs. Illustrates how other advances in instrumentation may contribute to clinical chemistry in the future. Topics include: biosensors, polarization spectroscopy, chemiluminescence, fluorescence, photothermal deflection, and chromatography in clinical…

Organic-Inorganic Hybrid Ruddlesden-Popper Perovskites: An Emerging Paradigm for High-Performance Light-Emitting Diodes.

PubMed

Liu, Xiao-Ke; Gao, Feng

2018-05-03

Recently, lead halide perovskite materials have attracted extensive interest, in particular, in the research field of solar cells. These materials are fascinating "soft" materials with semiconducting properties comparable to the best inorganic semiconductors like silicon and gallium arsenide. As one of the most promising perovskite family members, organic-inorganic hybrid Ruddlesden-Popper perovskites (HRPPs) offer rich chemical and structural flexibility for exploring excellent properties for optoelectronic devices, such as solar cells and light-emitting diodes (LEDs). In this Perspective, we present an overview of HRPPs on their structural characteristics, synthesis of pure HRPP compounds and thin films, control of their preferential orientations, and investigations of heterogeneous HRPP thin films. Based on these recent advances, future directions and prospects have been proposed. HRPPs are promising to open up a new paradigm for high-performance LEDs.

Detonation Properties Measurements for Inorganic Explosives

NASA Astrophysics Data System (ADS)

Morgan, Brent A.; Lopez, Angel

2005-03-01

Many commonly available explosive materials have never been quantitatively or theoretically characterized in a manner suitable for use in analytical models. This includes inorganic explosive materials used in spacecraft ordnance, such as zirconium potassium perchlorate (ZPP). Lack of empirical information about these materials impedes the development of computational techniques. We have applied high fidelity measurement techniques to experimentally determine the pressure and velocity characteristics of ZPP, a previously uncharacterized explosive material. Advances in measurement technology now permit the use of very small quantities of material, thus yielding a significant reduction in the cost of conducting these experiments. An empirical determination of the explosive behavior of ZPP derived a Hugoniot for ZPP with an approximate particle velocity (uo) of 1.0 km/s. This result compares favorably with the numerical calculations from the CHEETAH thermochemical code, which predicts uo of approximately 1.2 km/s under ideal conditions.

Toxicity of inorganic nanomaterials in biomedical imaging.

PubMed

Li, Jinxia; Chang, Xueling; Chen, Xiaoxia; Gu, Zhanjun; Zhao, Feng; Chai, Zhifang; Zhao, Yuliang

2014-01-01

Inorganic nanoparticles have shown promising potentials as novel biomedical imaging agents with high sensitivity, high spatial and temporal resolution. To translate the laboratory innovations into clinical applications, their potential toxicities are highly concerned and have to be evaluated comprehensively both in vitro and in vivo before their clinical applications. In this review, we first summarized the in vivo and in vitro toxicities of the representative inorganic nanoparticles used in biomedical imagings. Then we further discuss the origin of nanotoxicity of inorganic nanomaterials, including ROS generation and oxidative stress, chemical instability, chemical composition, the surface modification, dissolution of nanoparticles to release excess free ions of metals, metal redox state, and left-over chemicals from synthesis, etc. We intend to provide the readers a better understanding of the toxicology aspects of inorganic nanomaterials and knowledge for achieving optimized designs of safer inorganic nanomaterials for clinical applications. Copyright © 2014 Elsevier Inc. All rights reserved.

Cell-free biology: exploiting the interface between synthetic biology and synthetic chemistry

PubMed Central

Harris, D. Calvin; Jewett, Michael C.

2014-01-01

Just as synthetic organic chemistry once revolutionized the ability of chemists to build molecules (including those that did not exist in nature) following a basic set of design rules, cell-free synthetic biology is beginning to provide an improved toolbox and faster process for not only harnessing but also expanding the chemistry of life. At the interface between chemistry and biology, research in cell-free synthetic systems is proceeding in two different directions: using synthetic biology for synthetic chemistry and using synthetic chemistry to reprogram or mimic biology. In the coming years, the impact of advances inspired by these approaches will make possible the synthesis of non-biological polymers having new backbone compositions, new chemical properties, new structures, and new functions. PMID:22483202

Synthesis of the Plasma Chemistry Occurring in High Power CO2 Lasers

DTIC Science & Technology

1978-12-01

AFIT/GEP/PH/78D-13 44 SYNTHESIS OF THE PLASMA CHEMISTRY D D C OCCURRING IN HIGH POWER CO 2 LASERS ’Una CTHESIS David E. Toodle AFIT/GEP/PH/78D-13 2nd...inves- tivation is the plasma chemistry occurring in the laser discharge. These studies are ultimately related to the development of flowing and...aids in the understanding of plasma chemistry pro- cesses in the CO2 laser discharge. I would like to thank the whole staff of the Advanced Concepts

Bio-inorganic synthesis of ZnO powders using recombinant His-tagged ZnO binding peptide as a promoter.

PubMed

Song, Lei; Liu, Yingying; Zhang, Zhifang; Wang, Xi; Chen, Jinchun

2010-10-01

Inorganic-binding peptides termed as genetically engineered polypeptides for inorganics (GEPIs), are small peptide sequences selected via combinatorial biology-based protocols of phage or cell surface display technologies. Recent advances in nanotechnology and molecular biology allow the engineering of these peptides with specific affinity to inorganics, often used as molecular linkers or assemblers, to facilitate materials synthesis, which provides a new insight into the material science and engineering field. As a case study on this biomimetic application, here we report a novel biosynthetic ZnO binding protein and its application in promoting bio-inorganic materials synthesis. In brief, the gene encoding a ZnO binding peptide(ZBP) was genetically fused with His(6)-tag and GST-tag using E.coli expression vector pET-28a (+) and pGEX-4T-3. The recombinant protein GST-His-ZBP was expressed, purified with Ni-NTA system, identified by SDS-PAGE electrophoresis and Western blot analysis and confirmed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis. Affinity adsorption test demonstrated that the fusion protein had a specific avidity for ZnO nanoparticles (NPs). Results from the bio-inorganic synthesis experiment indicated that the new protein played a promoting part in grain refinement and accelerated precipitation during the formation of the ultra-fine precursor powders in the Zn(OH)(2) sol. X-ray diffraction (XRD) analysis on the final products after calcining the precursor powders showed that hexagonal wurtzite ZnO crystals were obtained. Our work suggested a novel approach to the application about the organic-inorganic interactions.

29 CFR 1915.1018 - Inorganic arsenic.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Inorganic arsenic. 1915.1018 Section 1915.1018 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1018 Inorganic arsenic. Note: The requirements applicable to shipyard employment under this...

29 CFR 1910.1018 - Inorganic arsenic.

Code of Federal Regulations, 2010 CFR

2010-07-01

... container in the change-room which prevents dispersion of inorganic arsenic outside the container. (vi) The.... (vii) The employer shall assure that the containers of contaminated protective clothing and equipment... apply precautionary labels to all shipping and storage containers of inorganic arsenic, and to all...

29 CFR 1915.1018 - Inorganic arsenic.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 7 2011-07-01 2011-07-01 false Inorganic arsenic. 1915.1018 Section 1915.1018 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1018 Inorganic arsenic. Note: The requirements applicable to shipyard employment under this...

29 CFR 1926.1118 - Inorganic arsenic.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 8 2011-07-01 2011-07-01 false Inorganic arsenic. 1926.1118 Section 1926.1118 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... Inorganic arsenic. Note: The requirements applicable to construction work under this section are identical...

Investigations of Nitrogen Oxide Plasmas: Fundamental Chemistry and Surface Reactivity and Monitoring Student Perceptions in a General Chemistry Recitation

ERIC Educational Resources Information Center

Blechle, Joshua M.

2016-01-01

Part I of this dissertation focuses on investigations of nitrogen oxide plasma systems. With increasing concerns over the environmental presence of NxOy species, there is growing interest in utilizing plasma-assisted conversion techniques. Advances, however, have been limited because of the lack of knowledge regarding the fundamental chemistry of…

Teachers' Questioning Techniques in Advanced Level Chemistry Lessons: A Tanzanian Perspective

ERIC Educational Resources Information Center

Kira, Ernest; Komba, Sotco; Kafanabo, Eugenia; Tilya, Frank

2013-01-01

This study investigated the extent to which teachers' questioning techniques and the way teachers handled students' responses facilitated students' learning and promoted their thinking skills. The study focused on three secondary schools in Dar es Salaam. The data collection process involved classroom observations during chemistry lessons and…

Holographic patterning of organic-inorganic photopolymerizable nanocomposites

NASA Astrophysics Data System (ADS)

Sakhno, Oksana V.; Goldenberg, Leonid M.; Smirnova, Tatiana N.; Stumpe, J.

2009-09-01

We present here novel easily processible organic-inorganic nanocomposites suitable for holographic fabrication of diffraction optical elements (DOE). The nanocomposites are based on photocurable acrylate monomers and inorganic nanoparticles (NP). The compatibility of inorganic NP with monomers was achieved by capping the NP surface with proper organic shells. Surface modification allows to introduce up to 50wt.% of inorganic NP in organic media. Depending on the NP nature (metal oxides, phosphates, semiconductors, noble metals) and their properties, the materials for both efficient DOE and multifunctional elements can be designed. Organic-inorganic composites prepared have been successfully used for the effective inscription of periodic volume refractive index structures using the holographic photopolymerization method. The nanocomposite preparation procedure, their properties and optical performance of holographic gratings are reported. The use of functional NP makes it possible to obtain effective holographic gratings having additional physical properties such as light-emission or NLO. Some examples of such functional polymer-NP structures and their possible application fields are presented. The combination of easy photo-patterning of soft organic compounds with physical properties of inorganic materials in new nanocomposites and the flexibility of the holographic patterning method allow the fabrication of mono- and multifunctional one- and multi-dimensional passive or active optical and photonic elements.

Social and Environmental Justice in the Chemistry Classroom

ERIC Educational Resources Information Center

Lasker, Grace A.; Mellor, Karolina E.; Mullins, Melissa L.; Nesmith, Suzanne M.; Simcox, Nancy J.

2017-01-01

Despite advances in active learning pedagogy and other methods designed to increase student engagement in the chemistry classroom, retention and engagement issues still persist, particularly with respect to women and minorities underrepresented in STEM (science, technology, engineering, and mathematics) programs. Relevancy also remains elusive in…

Lab-on-a-chip synthesis of inorganic nanomaterials and quantum dots for biomedical applications.

PubMed

Krishna, Katla Sai; Li, Yuehao; Li, Shuning; Kumar, Challa S S R

2013-11-01

The past two decades have seen a dramatic raise in the number of investigations leading to the development of Lab-on-a-Chip (LOC) devices for synthesis of nanomaterials. A majority of these investigations were focused on inorganic nanomaterials comprising of metals, metal oxides, nanocomposites and quantum dots. Herein, we provide an analysis of these findings, especially, considering the more recent developments in this new decade. We made an attempt to bring out the differences between chip-based as well as tubular continuous flow systems. We also cover, for the first time, various opportunities the tools from the field of computational fluid dynamics provide in designing LOC systems for synthesis inorganic nanomaterials. Particularly, we provide unique examples to demonstrate that there is a need for concerted effort to utilize LOC devices not only for synthesis of inorganic nanomaterials but also for carrying out superior in vitro studies thereby, paving the way for faster clinical translation. Even though LOC devices with the possibility to carry out multi-step syntheses have been designed, surprisingly, such systems have not been utilized for carrying out simultaneous synthesis and bio-functionalization of nanomaterials. While traditionally, LOC devices are primarily based on microfluidic systems, in this review article, we make a case for utilizing millifluidic systems for more efficient synthesis, bio-functionalization and in vitro studies of inorganic nanomaterials tailor-made for biomedical applications. Finally, recent advances in the field clearly point out the possibility for pushing the boundaries of current medical practices towards personalized health care with a vision to develop automated LOC-based instrumentation for carrying out simultaneous synthesis, bio-functionalization and in vitro evaluation of inorganic nanomaterials for biomedical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Bridging the Cognitive-Affective Gaps: Teaching Chemistry while Advancing Affective Objectives. The Singapore Curricular Experience

ERIC Educational Resources Information Center

Tan, Kok Siang; Goh, Ngoh Khang; Chia, Lian Sai

2006-01-01

Chemistry teachers face constraints when trying to integrate cognitive and affective objectives, and hence thoughtful lesson planning is required to achieve the goal. Chemistry teachers can educate students to be knowledgeable about chemical concepts, processes and the benefits of responsible practice by the chemical industry, while being aware,…

The effects of using screencasting as a multimedia pre-training tool to manage the intrinsic cognitive load of chemical equilibrium instruction for advanced high school chemistry students

NASA Astrophysics Data System (ADS)

Musallam, Ramsey

Chemistry is a complex knowledge domain. Specifically, research notes that Chemical Equilibrium presents greater cognitive challenges than other topics in chemistry. Cognitive Load Theory describes the impact a subject, and the learning environment, have on working memory. Intrinsic load is the facet of Cognitive Load Theory that explains the complexity innate to complex subjects. The purpose of this study was to build on the limited research into intrinsic cognitive load, by examining the effects of using multimedia screencasts as a pre-training technique to manage the intrinsic cognitive load of chemical equilibrium instruction for advanced high school chemistry students. A convenience sample of 62 fourth-year high school students enrolled in an advanced chemistry course from a co-ed high school in urban San Francisco were given a chemical equilibrium concept pre-test. Upon conclusion of the pre-test, students were randomly assigned to two groups: pre-training and no pre-training. The pre-training group received a 10 minute and 52 second pre-training screencast that provided definitions, concepts and an overview of chemical equilibrium. After pre-training both group received the same 50-minute instructional lecture. After instruction, all students were given a chemical equilibrium concept post-test. Independent sample t-tests were conducted to examine differences in performance and intrinsic load. No significant differences in performance or intrinsic load, as measured by ratings of mental effort, were observed on the pre-test. Significant differences in performance, t(60)=3.70, p=.0005, and intrinsic load, t(60)=5.34, p=.0001, were observed on the post-test. A significant correlation between total performance scores and total mental effort ratings was also observed, r(60)=-0.44, p=.0003. Because no significant differences in prior knowledge were observed, it can be concluded that pre-training was successful at reducing intrinsic load. Moreover, a significant

Click Chemistry in Complex Mixtures: Bioorthogonal Bioconjugation

PubMed Central

McKay, Craig S.; Finn, M.G.

2014-01-01

The selective chemical modification of biological molecules drives a good portion of modern drug development and fundamental biological research. While a few early examples of reactions that engage amine and thiol groups on proteins helped establish the value of such processes, the development of reactions that avoid most biological molecules so as to achieve selectivity in desired bond-forming events has revolutionized the field. We provide an update on recent developments in bioorthogonal chemistry that highlights key advances in reaction rates, biocompatibility, and applications. While not exhaustive, we hope this summary allows the reader to appreciate the rich continuing development of good chemistry that operates in the biological setting. PMID:25237856

Synthesis and Catalytic Activity of Ruthenium-Indenylidene Complexes for Olefin Metathesis: Microscale Experiments for the Undergraduate Inorganic or Organometallic Laboratories

ERIC Educational Resources Information Center

Pappenfus, Ted M.; Hermanson, David L.; Ekerholm, Daniel P.; Lilliquist, Stacie L.; Mekoli, Megan L.

2007-01-01

A series of experiments for undergraduate laboratory courses (e.g., inorganic, organometallic or advanced organic) have been developed. These experiments focus on understanding the design and catalytic activity of ruthenium-indenylidene complexes for olefin metathesis. Included in the experiments are the syntheses of two ruthenium-indenylidene…

Theoretical Chemistry Comes Alive: Full Partner with Experiment.

ERIC Educational Resources Information Center

Goddard, William A., III

1985-01-01

The expected thrust for theoretical chemistry in the next decade will be to combine knowledge of fundamental chemical steps/interactions with advances in chemical dynamics, irreversible statistical mechanics, and computer technology to produce simulations of chemical systems with reaction site competition. A sample simulation (using the enzyme…

Do Advanced Mathematics Skills Predict Success in Biology and Chemistry Degrees?

ERIC Educational Resources Information Center

Adkins, Michael; Noyes, Andrew

2018-01-01

The mathematical preparedness of science undergraduates has been a subject of debate for some time. This paper investigates the relationship between school mathematics attainment and degree outcomes in biology and chemistry across England, a much larger scale of analysis than has hitherto been reported in the literature. A unique dataset which…

Simulations of inorganic-bioorganic interfaces to discover new materials: insights, comparisons to experiment, challenges, and opportunities.

PubMed

Heinz, Hendrik; Ramezani-Dakhel, Hadi

2016-01-21

Natural and man-made materials often rely on functional interfaces between inorganic and organic compounds. Examples include skeletal tissues and biominerals, drug delivery systems, catalysts, sensors, separation media, energy conversion devices, and polymer nanocomposites. Current laboratory techniques are limited to monitor and manipulate assembly on the 1 to 100 nm scale, time-consuming, and costly. Computational methods have become increasingly reliable to understand materials assembly and performance. This review explores the merit of simulations in comparison to experiment at the 1 to 100 nm scale, including connections to smaller length scales of quantum mechanics and larger length scales of coarse-grain models. First, current simulation methods, advances in the understanding of chemical bonding, in the development of force fields, and in the development of chemically realistic models are described. Then, the recognition mechanisms of biomolecules on nanostructured metals, semimetals, oxides, phosphates, carbonates, sulfides, and other inorganic materials are explained, including extensive comparisons between modeling and laboratory measurements. Depending on the substrate, the role of soft epitaxial binding mechanisms, ion pairing, hydrogen bonds, hydrophobic interactions, and conformation effects is described. Applications of the knowledge from simulation to predict binding of ligands and drug molecules to the inorganic surfaces, crystal growth and shape development, catalyst performance, as well as electrical properties at interfaces are examined. The quality of estimates from molecular dynamics and Monte Carlo simulations is validated in comparison to measurements and design rules described where available. The review further describes applications of simulation methods to polymer composite materials, surface modification of nanofillers, and interfacial interactions in building materials. The complexity of functional multiphase materials creates

Deformable inorganic semiconductor

NASA Astrophysics Data System (ADS)

Kim, Dae-Hyeong; Cha, Gi Doo

2018-05-01

Unlike conventional inorganic semiconductors, which are typically brittle, α-Ag2S exhibits room-temperature ductility with favourable electrical properties, offering promise for use in high-performance flexible and stretchable devices.

Synthesis and Base Hydrolysis of a Cobalt(III) Complex Coordinated by a Thioether Ligand

ERIC Educational Resources Information Center

Roecker, Lee

2008-01-01

A two-week laboratory experiment for students in advanced inorganic chemistry is described. Students prepare and characterize a cobalt(III) complex coordinated by a thioether ligand during the first week of the experiment and then study the kinetics of Co-S bond cleavage in basic solution during the second week. The synthetic portion of the…

Joining Forces: The Chemical Biology-Medicinal Chemistry Continuum.

PubMed

Plowright, Alleyn T; Ottmann, Christian; Arkin, Michelle; Auberson, Yves P; Timmerman, Henk; Waldmann, Herbert

2017-09-21

The scientific advances being made across all disciplines are creating ever-increasing opportunities to enhance our knowledge of biological systems and how they relate to human disease. One of the central driving forces in discovering new medicines is medicinal chemistry, where the design and synthesis of novel compounds has led to multiple drugs. Chemical biology, sitting at the interface of many disciplines, has now emerged as a major contributor to the understanding of biological systems and is becoming an integral part of drug discovery. Bringing chemistry and biology much closer and blurring the boundaries between disciplines is creating new opportunities to probe and understand biology; both disciplines play key roles and need to join forces and work together effectively to synergize their impact. The power of chemical biology will then reach its full potential and drive innovation, leading to the discovery of transformative medicines to treat patients. Advances in cancer biology and drug discovery highlight this potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

Primary structure of inorganic polyphosphate/ATP-NAD kinase from Micrococcus flavus, and occurrence of substrate inorganic polyphosphate for the enzyme.

PubMed

Kawai, Shigeyuki; Mori, Shigetarou; Murata, Kousaku

2003-08-01

The gene encoding an inorganic polyphosphate/ATP-NAD kinase was cloned from Micrococcus flavus, and its primary structure was analyzed. Alignment of the primary structure with those of other characterized NAD kinases revealed candidate amino acid residues, mainly charged ones, that would be related to inorganic polyphosphate use. The alignment also showed that the primary structure found carried a protruding C-terminal polypeptide. Although the C-terminal polypeptide was demonstrated to be dispensable for the kinase activities, and was proposed to be removed in M. flavus, the entire primary structure including the C-terminal polypeptide was homologous with that of the ATP synthase beta chain. The inorganic polyphosphate used by the inorganic polyphosphate/ATP-NAD kinase as a phosphoryl donor was isolated from cells of M. flavus, suggesting that the ability of the enzyme to use inorganic polyphosphate is of physiological significance and is not an evolutionary trait alone.

From supramolecular chemistry towards constitutional dynamic chemistry and adaptive chemistry.