Gel systems based on self-assembled, amphiphilic ABA triblock copolymers in midblock-selective solvent form stable, spatially extended networks with controllable morphology and tunable viscoelastic behavior. In this work, we systematically evaluate the me...

Photoactive Thermoplastic Elastomers of Azobenzene-Containing Triblock Copolymers Prepared through to prepare a new series of ABA triblock copolymers that are photoactive thermoplastic elastomers. The samples interesting features to this type of thermoplastic elastomers. When the solution-cast ...

We have performed dynamic density functional theory calculations for an ABA triblock copolymer immersed in a B-attractive solvent. The triblock copolymer was parameterized for poly styrene-b-(ethylene- co-butylene)-b-(styrene) (SEBS), while the solvent wa...

This patent describes a method of enhancing the impact strength properties of a thermoplastic composition comprising at least one copolymer having recurring units of an imide monomer bearing an active hydrogen having a pKa value from about 4 to about 11 upon molding. The method comprises introducing into the composition an A-B-A ...

By a combination of theory and experiment, we investigate the factors that control self-assembly of ABC triblock and ABCA tetrablock copolymers. The focus of this study is to understand the effect of attaching or inserting a third block (block C) into AB diblock and ABA triblock copolymers. ...

The partitioning of diblock (AB) and triblock copolymers (ABA and BAB) into a slit pore with the B block set at the critical condition were investigated with lattice Monte Carlo simulations and were compared with the partitioning of a homopolymer (A) with the same length of the A block. The study aims to understand the effect of block ...

The self-assembly behavior of ABA coil-rod-coil triblock copolymers in a selective solvent was studied by a Brownian molecular dynamics simulation method. It was found that the rod midblock plays an important role in the self-assembly of the copolymers. With a decrease in the segregation strength, ?(RR), of rod ...

The self-assembly behavior of ABA coil-rod-coil triblock copolymers in a selective solvent was studied by a Brownian molecular dynamics simulation method. It was found that the rod midblock plays an important role in the self-assembly of the copolymers. With a decrease in the segregation strength, &eh;RR, of ...

We report on the effect of block copolymer domain size on transport of liquid mixtures through the membranes by presenting pervaporation data of an 8 wt% ethanol/water mixture through A-B-A and B-A-B triblock copolymer membranes. The A-block was chosen to facilitate ethanol transport while the B-blo...

... Title : Viscoelastic Properties of Homogeneous Triblock Copolymers of Styrene/alpha-Methyl Styrene and Their Polyblends with Homopolymers. ...

... sorption and permeability ofphosphoorganic agents in PEM made of sulfonated triblock copolymers of styrene and lower olefins by means of ...

... Accession Number : ADA533578. Title : Modeling Viscoelastic Properties of Triblock Copolymers: A DPD Simulation Study. ...

The biocompatibility of ABA triblock copolymers consisting of poly(L-lactide-co-glycolide) A blocks attached to a central poly(ethylene oxide), (PEO), B block was investigated under in vitro conditions. The ABA triblock copolymer was compared to commercially available ...

The self-consistent field theory (SCFT) complemented with the Poisson-Boltzmann equation is employed to explore self-assembly of polyelectrolyte copolymers composed of charged blocks A and neutral blocks B. We have extended SCFT to dissociating triblock copolymers and demonstrated our approach on three characteristic examples: (1) ...

The self-consistent field theory (SCFT) complemented with the Poisson-Boltzmann equation is employed to explore self-assembly of polyelectrolyte copolymers composed of charged blocks A and neutral blocks B. We have extended SCFT to dissociating triblock copolymers and demonstrated our approach on three characteristic examples: (1) ...

We simulate ABA triblock copolymer melts using a lattice Monte Carlo method, known as cooperative motion algorithm, probing various degrees of compositional asymmetry. Selected order-disorder transition lines are determined in terms of the segment incompatibility, quantified by product ?N , and the triblock ...

Anisotropy of the bridge fraction of middle isoprene block chains in the directions parallel and perpendicular to the shear flow direction in sheared films of sphere-forming polystyrene-b-polyisoprene-b-polystyrene triblock copolymers are examined by breaking stress under simple elongation measurements at a fast draw rate, which reflect the bridge ...

We demonstrate large-scale, fully-reversible, thermally-induced volumetric changes in layer-by-layer (LbL) electrostatically self-assembled thin films through the incorporation of A-B-A triblock copolymers, where A is a weak polyelectrolyte block, and B is a temperature-responsive block. Multilayers of a micelle-forming ...

The self-assembly of symmetric coil-rod-coil ABA-type triblock copolymer melts is studied by applying self-consistent field lattice techniques in a three-dimensional space. The self-assembled ordered structures differ significantly with the variation of the volume fraction of the rod component, which include lamellar, wave lamellar, ...

The self-assembly of symmetric coil-rod-coil ABA-type triblock copolymer melts is studied by applying self-consistent field lattice techniques in a three-dimensional space. The self-assembled ordered structures differ significantly with the variation of the volume fraction of the rod component, which include lamellar, wave lamellar, ...

Phase diagrams of the microphase morphologies for triblock copolymer melts are calculated for the weak segregation limit. The diagrams are found to be highly asymmetric with block copolymer composition.

In these studies, amphiphilic AB diblock and ABA triblock copolymers containing poly(lysine) (P(Lys)) were synthesized and their solution assembly studied using dynamic light scattering, circular dichroism spectroscopy and transmission electron microscopy. Rod-coil block copolymers containing P(Lys) are able to ...

A new ABA triblock copolymer of poly(styrene-block- methylacrylate-random-octadecylacrylate-block-styrene) (PS-b- PMA-r-PODA-b-PS) was synthesized by reversible addition fragmentation chain transfer polymerization. The triblock copolymer can generate a three-dimensional, physically crosslinked ...

Stimuli-responsive copolymers demonstrate diverse aggregation behavior in aqueous solution. In general, the molecular architecture and the balance of hydrophilic and hydrophobic volumes influence morphology. This study involves polypeptide-based ABA linear triblock and AB2 star copolymer (which structurally ...

... 1) triblock styrenic TPEs with elastomeric center blocks, 2) hydrogenated styrenic triblock copolymers, 3) vulcanized blends of EPDM elastomer and ...

Intensive research on block copolymers for their unique phase behavior and natural application as surfactants has gone on for a number of years now. The introduction of these materials into selective solvents has expanded the range of their application to diverse areas, from biological scaffolds and drug delivery to ceramics processing and nanocomposites. This dissertation ...

Polymer gel exists ubiquitously in our daily life, as in food, cosmetics, drugs, etc. From the structural point of view, the three-dimensional network can be found in a structural gel. On the other hand, in most experimental work, the gel is identified by the sharp increase of modules, i.e., the gel should have similar properties as those of a solid, which is named as mechanical gel. However, not ...

The phase behavior of symmetric ABA triblock copolymers containing a semiflexible midblock is studied by lattice Monte Carlo simulation. As the midblock evolves from a fully flexible state to a semiflexible state in terms of increase in its persistence length, different phase behaviors are observed while cooling the system from an ...

A Brownian Dynamics simulation was performed on 200 bead spring chains of triblock copolymer, A10B10A10. The repulsive interactions of A monomers (in good solvent) are modeled by the Weeks-Chandler-Anderson potential. The poor solvent attraction of the B monomers is described by a Lennard-Jones (LJ) potential. We have determined the phase diagram of 30% ...

Novel copolymers with controlled architectures can function as new building blocks for well-defined nanostructures on the basis of microphase separation, unlike conventional ABA triblock copolymers. A series of well-defined A(x)BA(x)-type block-graft copolymers consisting of soft middle ...

... Accession Number : ADA422626. Title : Styrene-butadiene-styrene Tri-block Copolymers Modified wit Polyhedral Oligomeric Silsesquioxanes. ...

... 4. TITLEANDSUBTITLE 5. FUNDING NUMBERS Modeling viscoelastic properties of triblock copolymers: A DPD simulation W91INF-07-l-0268 ...

The kinetics of the transformation from the hexagonal packed cylinder (hex) phase to the face-centered-cubic (fcc) phase was simulated using Brownian dynamics for an ABA triblock copolymer in a selective solvent for the A block. The kinetics was obtained by instantaneously changing either the temperature of the system or the well-depth ...

The kinetics of the transformation from the hexagonal packed cylinder (hex) phase to the face-centered-cubic (fcc) phase was simulated using Brownian dynamics for an ABA triblock copolymer in a selective solvent for the A block. The kinetics was obtained by instantaneously changing either the temperature of the system or the well-depth ...

In the present study, we describe the synthesis, characterization and self-assembly of a novel amphiphilic linoleic acid (LA)-modified polypeptide copolymer and its drug release behavior in vitro as well. Initially, an amphiphilic ABA triblock copolymer comprising polytetrahydrofuran (PTHF) as a central hydrophobic ...

A new injectable biodegradable hydrogel system with thermosensitive sol-gel transition behavior was developed. A series of A-B-A triblock copolymers consisting of Pluronic copolymer end-capped with D- or L-lactic acid oligomers (PL-LA(n)) with various chain lengths (n = 5,12) was synthesized. It was assumed that a ...

ABA triblock copolymers were synthesized by combining ring-opening metathesis polymerization (ROMP) of 1,5-cyclooctadiene (COD) with ring-opening polymerization of D,L-lactide. Hydroxyl-functionalized telechelic polyCOD was prepared by taking advantage of chain transfer during ROMP of COD using the acyclic chain transfer agent ...

Triblock copolymers have traditionally been synthesized with conventional organic components. However, triblock copolymers could be synthesized by the incorporation of two incompatible protein-based polymers. The polypeptides would differ in their hydroph...

... Study of Phase Behaviors in Diblock Copolymers in Selective Solvents. ... MD Self-consistent Theory of Block Copolymer Blends: Selective Solvent. ...

We investigated the interaction between DPPC (Dipalmitoyl phosphatidylcholine) bilayer and polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) triblock copolymers using coarse grained simulation. We simulated two systems of DPPC bilayer and PEO-PPO-PEO triblock copolymer containing different ...

Advanced polymerization techniques enable the synthesis of a variety of polymeric materials with well-defined chain architectures, compositions, and tunable molecular weights and molecular weight distributions. The inherent chain length polydispersity of polymers derived from these syntheses affects their ultimate materials properties and applications. Relying on tandem ring-opening metathesis ...

Recent experimental observations have suggested an intimate connection between the chain conformations and mechanical properties of semicrystalline multiblock copolymers. Motivated by these studies, we present a theoretical study evaluating the bridging/looping fractions in a model of semicrystalline multiblock copolymers. We model the noncrystalline block ...

Recent experimental observations have suggested an intimate connection between the chain conformations and mechanical properties of semicrystalline multiblock copolymers. Motivated by these studies, we present a theoretical study evaluating the bridging/looping fractions in a model of semicrystalline multiblock copolymers. We model the noncrystalline block ...

An amphiphilic thermo-responsive ABA triblock copolymer, poly(methyl methacrylate)-b-poly(N-isopropylacrylamide-co-poly(ethylene-glycol) methyl ether methacrlate)-b-poly(methyl methacrylate) (PMMA-b-P(NIPAM-co-PEGMEMA)-b-PMMA), was designed and synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization, and ...

A hybrid self-consistent field theory model (H-SCFT) was utilized to model the morphology of nanocomposities composed of cylinder forming ABA triblock copolymer and large nanoparticles (radius on the order of 10 nm). In this system, the size of the nanoparticles is comparable to the cylindrical domains such that nanoparticle ...

This patent describes a method for permeability control of a subterranean formation and for enhancing oil recovery from the subterranean formation. The method comprising injecting into the subterranean formation an aqueous solution comprised of a block copolymer having the structural form of ABA triblock or (AB){sub n} multiblock ...

We performed Monte Carlo simulation of water/oil/ABA triblock amphiphiles with hydrophilic A and hydrophobic B, on a 51�51�51 simple cubic lattice with periodic boundary conditions in x- and y-directions. Bond fluctuation model(BFM) was used to describe amphiphile, where excluded volume effect and flexible movement of polymer bonds are ascertained. The ...

Novel, short outer block sulfonated SEPS triblock copolymers were synthesized, characterized via DMA and SAXS. The polymers exhibited microphase separation in which the minor component, sulfonated polystyrene formed a dispersed, hard phase in the soft, et...

This report describes our achievement in the investigation of the influence of structure on diffusion in styrene-ethylene/ butylene-styrene triblock copolymers (SEBS) during the period of June 1, 2006 to November 30, 2006. This type of triblock copolymers...

... Accession Number : ADA532985. Title : Macroscopic Modeling of A3B15A3 Triblock Copolymers in B Solvent. Descriptive Note : Final rept. ...

A new thermoreversible ion gel with high ionic conductivity was developed through the self-assembly of a triblock copolymer, by choosing appropriate associating end-blocks for the ionic liquid. PMID:17594036

Synperonic F-108 (generic name, �pluronic�) is a micelle forming triblock copolymer of type ABA , where A is polyethylene oxide (PEO) and B is polypropylene oxide (PPO). At high temperatures, the hydrophobicity of the PPO chains increase, and the pluronic molecules, when dissolved in an aqueous medium, self-associate into ...

Thermoplastic elastomers (TPEs) are typically symmetric ABA triblock copolymers made up of a ``soft'' rubbery midblock (B) and ``hard'' endblocks (A) that are usually glassy. We have used living ring-opening metathesis polymerization (ROMP) and subsequent hydrogenation to synthesize TPEs with glassy and semicrystalline ``hard'' blocks. ...

... Title : Synthesis and SAXS Characterization of Sulfonated Styrene-Ethylene/ Propylene-Styrene Triblock Copolymers. Corporate ...

... Abstract : Search for novel polymeric electrolyte membranes (PEM) suitable as permselective diffusion barriers is one of the key problems in ...

We have developed a hierarchical process that combines linear triblock copolymers into concentric globular subunits through strong chemical bonds and is followed by their supramolecular assembly via weak noncovalent interactions to afford one-dimensionally assembled, dynamic cylindrical nanostructures. The molecular brush architecture forces ...

) triblock copolymer with a midblock-selective aliphatic mineral oil. To discern the influence of midblock/oil that the morphologies and properties of such triblock copolymer/oil blends are sensitive to the chemical address: Department of Materials Science & Engi- neering, University of Pennsylvania, ...

... Accession Number : ADD403351. Title : ABA block copolymers of dienes and cyclic sulfides. Corporate Author : AKRON UNIV OHIO. ...

A telechelic poly(epsilon-caprolactone) having a degree of polymerization (DP) around 25 and two 4-aminobenzoyl chain ends was used as a macroinitiator for the ring-opening polymerization of various alpha-amino acid N-carboxyanhydrides (NCAs). Glycine-NCA, L-alanine-NCA, L-phenylalanine-NCA, and gamma-benzyl-L-glutamate-NCA served as monomers and the NCA/macroinitiator ratio was varied between ...

Three types of block copolymers were used to prepare block copolymer ionomers: (1) a triblock copolymer of styrene and ethylene-co-butylene (SEBS) obtained commercially and diblock and triblock copolymers of styrene and ethylene-co-propylene (SEP and SEPS...

The effects of PEO-PPO-PEO triblock copolymers, mainly Poloxamer 188, on phospholipid membrane integrity under osmotic gradients were explored using giant unilamellar vesicles (GUVs). Fluorescence leakage assays showed two opposing effects of P188 on the structural integrity of GUVs depending on the duration of their incubation time. A two-state transition ...

Novel hydrophilic triblock copolymers which form micelles in aqueous solution were studied by static and dynamic light scattering (SLS and DLS), small angle neutron scattering (SANS) and densitometry. The polymers were symmetric A-B-A block copolymers having two poly(ethylene oxide) (PEO) tail blocks and a ...

Two series of amphiphilic triblock surface active block copolymers (SABCs) were prepared through chemical modification of two polystyrene-block-poly(ethylene-ran-butylene)-block-polyisoprene ABC triblock copolymer precursors. The methyl ether of poly(ethylene glycol) [M(n) approximately 550 g/mol (PEG550)] and a ...

Ion gels, comprising a polymeric network solvated by an ionic liquid, are of great interest as, e.g., gate dielectrics in plastic electronics, polymer electrolytes with high ionic conductivity, actuators and artificial muscles, gas separation media, and sensors. We have explored the thermoreversible gelation of a model system containing poly(2-vinyl pyridine-b-ethyl acrylate-b-2-vinyl pyridine) ) ...

Living cationic polymerization reactions using organotellurium compounds as initiators are reported. Polymerization of vinyl ethers in the presence of an organotellurium initiator and a Lewis acid, such as In(OTf)(3) and BF(3)�OEt(2), affords well-controlled poly(vinyl ether)s with predetermined molecular weights and narrow molecular-weight distributions. Poly(meth)acrylates possessing ...

2-(Dimethylamino)ethyl methacrylate (DMA) was block copolymerized with methyl methacrylate (MMA) using group transfer polymerization to give four AB diblock, ABA triblock, and BAB triblock copolymers of low polydispersity (Mw/Mn < 1.20). In addition, a near-monodisperse styrene-functionalized DMA-based ...

We analyze the phase behavior and the dynamic moduli of ternary mixtures composed of styrene-poor diblock (styrene-isoprene, SI) and triblock (SIS) copolymers in a midblock-selective solvent (squalane). In the absence of diblocks, macrophase separation is clearly observable at low triblock concentrations, while a percolated network is ...

Polyacetylene- block-polynorbornene- block-polyacetylene triblock copolymers were made via the Durham precursor route using a dititanacyclobutane living metathesis catalyst. I.R. and u.v-v.i.s. spectroscopic investigations on stretch-oriented copolymer fi...

Ordered structures in thin films of ABC triblock copolymers are studied experimentally and theoretically in order to be applied to fabrication of nanoscale electronic devices. A field-theoretic simulation method based on the self-consistent field theory is used to generate useful nanopatterns starting with a random configuration of compositions. The main ...

A series of AB diblock and ABA triblock copolymers consisting of poly(Lysine(Z)) (A = P(Lys(Z))) and poly(propylene oxide) (B = PPO) were synthesized and found to form stable, rigid organogels in THF (ca. 1 1.5 wt.% solutions) at room temperature. In these systems, the protecting group on the P(Lys) side-chains remains intact. As ...

The preparation of a long-chain aliphatic alpha,omega-diene from plant oil derivatives and its subsequent polymerization through acyclic diene metathesis (ADMET) is described. The ADMET bulk polymerization of the thus-obtained monomer, undecyl undecenoate, was investigated and optimized by applying ruthenium-based metathesis catalysts from Grubbs and Hoveyda-Grubbs, leading to ...

Page 1. Transport Properties of Sulfonated Poly(styrene-b-isobutylene-b-styrene) Triblock Copolymers at High Ion-Exchange Capacities ...

... Title : Transport Properties of Sulfonated Poly (Styrene-b-isobutylene-b-styrene) Triblock Copolymers at High Ion-Exchange Capacities. ...

... HPLC gave a single peak ... grafting of POSS to the continuous soft phase causes a gradual ... discrete hard phases with the increasing amount of POSS ...

In the last several years, there has been growing interest in the use of synthetic surfactants to augment cellular repair. Amphiphilic triblock copolymers such as PEO-PPO-PEO have been demonstrated to aid in the repair of a variety of cells. In spite of the reported success of these compounds in clinical trials, the mechanism of their interaction with cell ...

Purpose: Investigate the delivery of camptothecin in the presence of vitamin D3 with triblock copolymer-derived nanospheres that will increase the solubility of both of the drugs and provide protection to the camptothecin's lactone ring, resulting in its ...

... Title : Morphology and Phase Transitions in Styrene-Butadiene-Styrene Triblock Copolymer Grafted with Isobutyl Substituted Polyhedral Oligomeric ...

... styrene (SBS) triblock copolymers (and their blends with SBR) were studied using torsional pendulum tests, and dynamic mechanical analysis. ...

1 2 Submicron Magnetic Multilayers Thin Cross-Linked Films 3 4 Triblock Copolymer Brushes Acoustic Wave Devices...

Triblock copolymer PLA-PEG-PLA were synthesized using ring opening polymerization with different LA/EG ratio. Micellar aggregates were prepared from these block copolymers and characterized. The degradation characteristics of selected copolymers were assessed in both micellar and film forms. Surface segregation of ...

It is known that PEO-PPO-PEO triblock copolymers interact with lipid membranes but can have opposing effects on membrane integrity - they can behave either as membrane sealants or as permeabilizers depending on their architecture. To understand the origin of their biomedical functionality, interactions between PEO-PPO-PEO triblock ...

Sulfonated block copolymer ionomers possessing short (1K g/mol) styrene blocks and various rubber block lengths were synthesized via sequential anionic polymerization of styrene, isoprene, and styrene followed by hydrogenation and sulfonation. The ionomer...

A triblock copolymer of styrene-butadiene-styrene (SBS) was blended with a high and a low molecular weight polybutadiene (designated as PB(H) and PB(L) respectively). Electron micrographs of these blends show that PB(L) was solubilized into the butadiene ...

In an effort to mimic the growth of natural bone, self-assembling, micelle and gel-forming copolymers were used as a template for calcium phosphate precipitation. Because of the cationic characteristics imparted by PDEAEM end group additions to commercial...

Morphological behavior of hydrogen-bonded self-assembled structures of blends of two diblock copolymers Poly(styrene-b-ethylene oxide) and poly(butadiene-b-acrylic acid) were studied by small angle x-ray scattering and transmission electron microscopy with a goal to obtain morphologies equivalent to triblock copolymers. Depending on ...

Fabrication of next-generation biologically active materials will involve the integration of proteins with synthetic membrane materials toward a wide spectrum of applications in nanoscale medicine, including high-throughput drug testing, energy conversion for powering medical devices, and bio-cloaking films for mimicry of cellular membrane surfaces toward the enhancement of implant ...

ABA-type block copolymers (abbreviated as LEL) composed of poly(L-leucine) (PLL) as the A component and poly(ethylene glycol) (PEG) as the B component were synthesized by ring-opening polymerization of L-leucine N-carboxyanhydride initiated by primary amino group located at both ends of PEG chain. A silver sulfadiazine (AgSD)-impregnated wound dressing of ...

Rapid cross-linking of elastin-like polypeptides (ELPs) with hydroxymethylphosphines (HMPs) in aqueous solution is attractive for minimally invasive in vivo implantation of biomaterials and tissue engineering scaffolds. In order to examine the independent effect of the location and number of reactive sites on the chemical cross-linking kinetics of ELPs and the mechanical properties of the ...

Rapid cross-linking of elastin-like polypeptides (ELPs) with hydroxymethylphosphines (HMPs) in aqueous solution is attractive for minimally invasive in vivo implantation of biomaterials and tissue engineering scaffolds. In order to examine the independent effect of the location and number of reactive sites on the chemical cross-linking kinetics of ELPs and the mechanical properties of the ...

This study examines in vitro and in vivo biodegradation and biocompatibility of a thermogelling polymeric material, which we call a mixture hydrogel. The mixture contains two ABA-type triblock copolymers poly(d,l-lactic acid-co-glycolic acid)-b-poly(ethylene glycol)-b-poly(d,l-lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) with ...

Transport properties of sulfonated poly(styrene-b-isobutylene-b- styrene) (S-SIBS) triblock copolymers were examined as a function of ion- exchange capacity (IEC), specifically at high IECs (up to -2 mequiv/g). The proton conductivity of S-SIBS was -1 ord...

silica6 and polystyrene9 spheres as hard templates, respectively. On the other hand, hollow CdS spheres briefly reported a novel synthesis of hollow semiconductor ZnS nanospheres in aqueous solutionsSynthesis of Submicrometer-Sized CdS Hollow Spheres in Aqueous Solutions of a Triblock Copolymer

. Atom Transfer Radical Polymerization (ATRP)9,10,11 then is utilized to produce triblock copolymers are then subsequently reduced to hydroxy groups. The hydroxy end groups were easily converted to bromoester end groups- hexylthiophene) followed by atom transfer radical polymerization (ATRP) of methyl acrylate. Acknowledgements

oriented via the roll-caster are a composite of responses from grains of cylinders with a distribution(styrene-block-isoprene-block-styrene) (SIS) triblock copolymer with a polystyrene (PS) cylinder morphology was processed via roll-casting to produce a near single-crystal texture. Deformation experiments normal to the cylinder axis were carried

A-B diblock copolymers of polystyrene-block-poly(methyl methacrylate) were prepared by anionic polymerization and labeled with one naphthaleneeither at the polystyrene block end or at the polystyrene/methyl methacrylate block boundary. B-A-B triblock copo...

.4), formation of nano- objects (solution scatters light) � Cryo TEM shows vesicles More cryo TEM pictures needed of the vesicles � Several experiments on insulin encapsulation � Animal studies #12;Acknowledgments � Jerome ClaverieBiocompatible Triblock Copolymer Self-Assembled in Vesicles: Application to Drug Delivery #12;Oral

Dissipative particle dynamics (DPD), a mesoscopic simulation approach, has been used to investigate the effect of the arrangement of the microstructure and the effect of the volume fraction on the structural properties of the immiscible polyethylene (PE)/poly(L-lactide) (PLLA) polymer in the triblock copolymer system. In this work, the interaction ...

The effects of PEO-PPO-PEO triblock copolymers, mainly Poloxamer 188, on phospholipid membrane integrity under osmotic gradients were explored using giant unilamellar vesicles (GUVs). Fluorescence leakage assays showed two opposing effects of P188 on the structural integrity of GUVs depending on the duration of their incubation time. A two-state transition ...

The order-order transition temperature (T(OOT)) in blends of poly(styrene-b-isoprene-b-styrene) (S-I-S) triblock copolymer and polyisoprene (PI) homopolymer was investigated by using synchrotron small-angle X-ray scattering (SAXS). Pure triblock copolymer undergoes an order-order transition (OOT) from hexagonally ...

The exploration of the styrene-rich network phase window in the poly(isoprene-b-styrene-b-methyl methacrylate) [ISM] system is achieved using neat triblock copolymers and via the blending of ISM triblock copolymers with poly(styrene) and poly(methyl methacrylate) homopolymers. Morphological characterization of the ...

We perform molecular simulations to study the self-assembly of block copolymer tethered cubic nanoparticles. Minimal models of the tethered nanoscale building blocks (NBBs) are utilized to explore the structures arising from self-assembly. We demonstrate that attaching a rigid nanocube to a diblock copolymer affects the typical equilibrium morphologies ...

Methods for functionalizing micrometer-sized colloidal spheres with three or more zones of chemical functionality (ABA or ABC) are described. To produce ABA triblock colloids, we functionalized the north pole, south pole, and equator to produce what we call X, Y, and K functionality according to the number of allowed nearest neighbors ...

Polymers, elastomers, and plastics PACS.82.70.Dd Colloids Abstract. Diblock copolymer polystyrene-polyisoprene for polyisoprene and a theta solvent for polystyrene at Te = 70 �C. The molecular mass of the copolymer is I-I x 10 of copolymer chains in the micelle have to be taken into consideration. For example, telechelic ...

In recent years, research has expanded the uses of triblock copolymer gels to a wide variety of applications including everything from ceramics processing to regenerative medicine and drug delivery. The research presented in this dissertation focuses on a physically crosslinked, block copolymers gel system in a selective solvent. This ...

Oscillatory shear rheometry is used to study the mechanical response of single-walled carbon nanotubes dispersed in solutions of acrylic diblock or triblock copolymers in 2-ethyl-1-hexanol. Thermal transitions in the copolymer solutions provide a route for the easy processing of these composite materials, with excellent dispersion of ...

Three types of ionic A-B-A block copolymers have been studied. These are polystyrene-polyisoprene-polystyrene copolymer with sodium sulfonate groups attached to the rubbery center block, polystyrene-polybutadiene-polystyrene with quaternary ammonium group...

Self-consistent field theory is used to study the self-assembly of a triblock copolymer melt. Two different external factors (temperature and solvent) are shown to affect the self-assembly. Either one or two-step self-assembly can be found as a function of temperature in the case of a neat triblock melt, or as a function of increasing ...

Photophysical measurements have been used to characterize a series of well-defined block copolymers labeled with aromatic chromophores and quenchers. These include measurements of (1) energy migration kinetics in the homopolymers and diblock copolymers; (2) solvent effects (CH{sub 2}Cl{sub 2}, THF, THF/CH{sub 3}CN and CHCl{sub 3}) on exciplex emission in ...

In this work, we investigate the phase behavior of ABC triblock copolymer thin film confined between brush-coated substrates by using the self-consistent field theory in three dimensions. The coated polymers identical with the end block A and the middle block B of the ABC triblock copolymer are considered. The ...

Ring-opening metathesis polymerization of methyltetracyclododecene with Mo(CHCMe[sub 3]) (NAr) (OCMe[sub 3])[sub 2] (Ar = 2,6-diisopropylphenyl) followed by termination with an excess of conjugated dialdehyde yielded end-functionalized homopolymers with low polydispersities. Subsequent linking of the homopolymers with either a conjugated, difunctional molybdenum alkylidene complex or a ...

The phase behavior of ABC star triblock copolymers is examined using real-space self-consistent mean-field theory. The central part of the triangular phase diagram for ABC triblock copolymers with equal A/B, B/C, and C/A interactions is determined by comparing the free energy of a number of candidate ordered ...

The phase behavior of ABC star triblock copolymers is examined using real-space self-consistent mean-field theory. The central part of the triangular phase diagram for ABC triblock copolymers with equal A/B, B/C, and C/A interactions is determined by comparing the free energy of a number of candidate ordered ...

Elongation deformation was conducted on a polystyrene-block-polyisoprene-block-polystyrene (SIS) triblock copolymer which contains cylindrical microdomains composed of polystyrene block chains in matrix of polyisoprene block chains. The extensional flow behavior of this deformation triblock copolymer melt, which ...

High molecular weight, high functionality diamino telechelic polybutadienes (TPBs) were synthesized by ring-opening metathesis polymerization (ROMP) of 1,5-cyclooctadiene (COD) in the presence of a chain transfer agent, 1,8-dicyano-4-octene, followed by lithium aluminum hydride reduction. Melt coupling of diamino TPB with anhydride-terminated polystyrene (PS-anh) resulted in the formation of ...

Semifluorinated-quaternized triblock copolymers (SQTCs) were synthesized by chemical modification of polystyrene-block-poly(ethylene-ran-butylene)-block-polyisoprene ABC triblock copolymers. Surface characterization of the polymers was performed by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray ...

The use of synthetic polymerization techniques (e.g., controlled radical polymerizations) that often yield polydispersity indices greater than 1.1 is becoming more widespread. Advances in these methodologies have increased the number of monomers amenable to incorporation in block copolymers and will potentially drive commercial costs down. Since many block ...

ABC-type block copolymers exhibit morphological diversity not found in diblock copolymers and are becoming a versatile route to nanoscale devices. ABC triblocks are capable of self-assembling into triply-periodic network structures with a high degree of internal interfacial area and tailored chemical and mechanical properties. These ...

Well-ordered block copolymer microdomains were obtained by blending Pluronic PEO-PPO-PEO triblock copolymer surfactants with the room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate. The selective association of the ionic liquid with the PEO blocks increases the segregation strength by increasing the effective ...

Fluorescence spectroscopy is used to probe local environments within regions of different polarity and hydrophobicity in aqueous aggregates of PEO(109)-PPO(41)-PEO(109) triblock copolymers. These copolymer aggregates have well characterized microphases in aqueous solution. Concentrations and temperatures for our studies are chosen such ...

Lipiodol-loaded poly(oxyethylene)-block-poly(oxypropylene)- block-poly(oxyethylene) triblock Information, NLM, NIH, Bethesda, MD, micad@ncbi.nlm.nih.gov Chemical name: Lipiodol-loaded poly information. Background [PubMed] Lipiodol-loaded poly

Ultrasonic velocity measurements were made on a series of Pluronics i.e., tri-block non-ionic co-polymers of poly(ethylene oxide) poly(propylene oxide) poly(ethylene oxide) in solvents showing near ideal and non-ideal behavior. Aqueous solutions of the Pl...

Sequential living anionic polymerization techniques were used for synthesis of block copolymers of styrene and tert-butyl methacrylate. Cumylpotassium and naphthalene-potassium complexes served as initiators for diblock and triblock copolymers, respective...

Mid-functionalized ABC triblock copolymers with a short central B block were synthesized via the RAFT process, and further used as well-defined V-shaped copolymers to graft onto graphene oxide by coupling reactions. PMID:21769333

The surface-induced ordering in thin films of asymmetric deuterated polystyrene (dPS)--poly(vinylpyridine) (PVP) diblock and triblock copolymers of comparable polymerization index and PVP volume fraction (f [approximately] 0.25) was studied using transmission electron microscopy, atomic force microscopy, secondary ion mass spectrometry, and neutron ...

We have discovered systems of molecules with the architecture of miniaturized triblock copolymers that self assemble into nanostructures highly regular in size and shape. In the system described here, a mushroom-shaped supramolecular structure of about 20...

Fruitful results were achieved by investigating the structure and dynamics of self-assembled diblock and triblock copolymers by means of a combination of physical techniques, including static and dynamic light scattering, small angle x-ray scattering, sma...

Surfactant and lipid vesicles and their self-assembly processes are of interest in many fields and implications including materials science, drug delivery systems, cosmetics, pesticides, biomembranes, catalysis, artificial photosynthesis, and microenviron...

In the last several years, there has been growing interest in the use of synthetic surfactants to augment cellular repair. Amphiphilic triblock copolymers such as PEO-PPO-PEO have been demonstrated to aid in the repair of a variety of cells. In spite of t...

This patent describes a lubricating oil composition comprising a triblock copolymer containing terminal hydrogenated polyisoprene blocks and a central polymeric block containing predominantly monoalkenyl aromatic hydrocarbon monomer units.

We report the study of melt phase behavior of poly(isoprene-b-styrene-b-ethylene oxide) as our model ABC triblock copolymer. Previous investigations on this system have discovered a network phase with O^70 space group symmetry in an orthorhombic lattice adjacent to network phases with cubic lattice symmetries, namely, alternating gyroid and core-shell ...

Semi-dilute solutions of PMMA-PnBA-PMMA triblock co-polymers in alcohols are excellent binder materials for a novel ceramics processing method, thermo-reversible gel casting. Processing methods based on this technology offer a low cost alternative to traditional slip and gel casting techniques. The rapid transition of these gels from freely flowing liquids ...

Sequential ring-opening metathesis polymerization of norbornene and 7,8-bis(trifluoromethyl)tricyclo[4.2.2.0[sup 2.5

In this work, a set of well-defined polylactide-b-poly(ethylene-co-1-butene)-b-polylactide (PLA-PEB-PLA) triblock copolymers were synthesized by controlled ring-opening polymerization of corresponding lactide monomers (L-lactide and racemic mixture of D- and L-lactides) using Sn(Oct)2 as the catalyst. The volume fractions of PLA in the ...

Novel micelles from biamphiphilic triblock copolymer poly(ethylene glycol)-b-poly(?-caprolactone)-b-poly(acrylic acid) (PEG-b-PCL-b-PAA) as new multifunctional nanocarriers to delivery anticancer drugs were evaluated. The well-defined triblock copolymers prepared by controlled polymerizations self-assembled into ...

Retinal detachment is repaired by external and internal tamponade. There is as yet no direct internal tamponade which provides 360 deg coverage to the retina. With a magnetized encircling scleral buckle, magnetic fluids would provide 360 deg encircling internal tamponade. Our magnetic fluid is a dispersion of ultrafine (4-10 nm) magnetic particles in silicone secured with ...

Supramolecular complexes of a poly(tert-butoxystyrene)-block-polystyrene-block-poly(4-vinylpyridine) triblock copolymers and less than stoichiometric amounts of pentadecylphenol (PDP) are shown to self-assemble into a core-shell gyroid morphology with the core channels formed by the hydrogen-bonded P4VP(PDP)complexes. After structure formation, PDP was ...

This thesis is the culmination of several recent studies focused on the surface characterization of polyphosphazenes specifically the properties of water repellency or hydrophobicity. Chapter 1 is a background account of polyphosphazene chemistry and the hydrophobicity of polyphosphazenes. Chapter 2 provides an examination of the role of surface morphology on hydrophobicity. This study deals in ...

A novel noncovalent adsorbed coating for CE has been prepared and explored. This coating was based on quaternized poly(2-(dimethylamino)ethyl methacrylate)-block-poly(ethylene oxide)-block-poly(2-(dimethylamino)ethyl methacrylate) (QDED) triblock copolymer which was synthesized by atomic transfer radical polymerization (ATRP) in our laboratory. The ...

This article presents a systematic study of the effect of pH on the rheological properties of aqueous micellar gels formed from 10.0 wt % aqueous solutions of a thermo- and pH-sensitive ABA triblock copolymer, poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid)-b-poly(ethylene oxide)-b-poly(ethoxydi(ethylene glycol) ...

Stimuli-responsive copolymers demonstrate diverse aggregation behavior in aqueous solution, where the molecular architecture and hydrophilic/hydrophobic content influences morphology. The solution morphology of poly(lysine)-b-poly(propylene oxide)-b-poly(lysine) (KPK) triblock copolymers with high lysine content (> 75 wt.%) will be ...

A novel triblock copolymer for use in an injectable pH- and temperature-sensitive hydrogel is synthesized by conjugating poly(amidoamine) (PAA) to poly(ethylene glycol): poly(amidoamine)-poly(ethylene glycol)-poly(amidoamine) (PAA-PEG-PAA). The polymer was characterized with (1)H NMR and gel permeation chromatography in the diluents CDCl(3) and CHCl(3), ...

The effects of solution extrusion on the mechanical properties of polycyclohexylethylene-b-polyethylene diblock (CE), triblock (CEC) and pentablock (CECEC) copolymers were investigated. The tensile mechanical properties of the triblock and pentablock improved significantly, relative to melt extrusion, resulting in an ultimate tensile ...

Polymer vesicles made from poly(isoprene-b-styrene-b-2-vinyl pyridine) (PI-b-PS-b-P2VP) triblock copolymer confined within the nanopores of an anodic aluminum oxide (AAO) membrane are studied. It was found that these vesicles have well-defined, nanoscopic size, and complex microphase-separated hydrophobic membranes, comprised of the PS and PI blocks, while ...

Novel ABA-type amphiphilic triblock copolymers composed of poly (ethylene glycol) (PEG) as hydrophilic segment and poly (2,2-dimethyltrimethylene carbonate) (PDTC) as hydrophobic segment were synthesized by ring-opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) initiated by dihydroxyl PEG. The influence of introducing ...

ABA triblock copolymer, poly(ethylene glycol)-poly(butylene adipate)-poly(ethylene glycol) (PEG-PBA-PEG) could form micelle-like nanoparticles due to their amphiphilic characteristic. The mechanism of nanoparticle formation is based on the modified oil in water (O/W) emulsion by emulsifying acetone solution of ...

Dendritic micelles formed from amphiphilic dendritic ABA triblock copolymers based on organic linear poly(ethylene oxide) and inorganic dendritic block containing silicon atoms (OSC-D(Gn)-PEO-D(Gn)-CSO, n=1-3)(1) were evaluated as drug delivery vehicles for a drug in both lipophilic and hydrophilic forms. The physical parameters of the ...

Thermoplastic elastomers (TPEs) are typically ABA triblock copolymers made up of a rubbery midblock (B) and glassy endblocks (A). If instead the hard segments were crystalline, microphase separation could be driven by crystallization from a lower-viscosity single-phase melt. We use living ring-opening metathesis polymerization and ...

Thermoplastic elastomers composed of styrenic triblock copolymers are of great importance in applications such as adhesives and vibration dampening due to their resilience and facile processing. The swelling of these polymers by adding midblock selective solvents or oligomers provides an easy route by which to modify the morphology and mechanical behavior ...