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Showing 1 to 15 of 15 for “"multiblock copolymer"”.
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Multiblock Copolymer Synthesis in Aqueous Heterogeneous Systems
… macromolecular architectures such as multiblock copolymers can now be synthesized. Synthetic chemical techniques have been implemented in homogeneous systems to achieve multiblock copolymers with time and resource efficiency, however, the synthetic procedure is limited to few monomer …
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Synthesis and characterization of pH/temperature dual sensitive multiblock copolymer for drug delivery
… objective of this study was to develop a novel multiblock copolymer (MBCP) with temperature/pH dual-sensitivity which undergoes gelation at body temperature and degradation at acidic pH for controlled drug delivery applications. The MBCP with molecular weight of 42000 Da was synthesized by …
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Solution-casting of Disulfonated Poly(arylene ether sulfone) Multiblock Copolymer Films for Proton Exchange Membranes
… of disulfonated poly(arylene ether sulfone) multiblock copolymer films from the viewpoint of phase separation of block copolymers. Of equal importance to this work, is a possibility of utilizing a rheological technique for monitoring the transformation and kinetics of block copolymers during …
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Synthesis and Characterization of Multiblock Copolymer Proton Exchange Membranes for High Temperature Fuel Cell Applications
… domain connectivity. In this dissultation, novel multiblock copolymers based on disulfonated hydrophilic-hydrophobic multiblocks were synthesized and investigated for their potential application as PEMs. The relationship between copolymer chemical composition and resulting properties was probed …
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Morphological and Structure-Property Analyses of Poly(arylene ether sulfone)-Based Random and Multiblock Copolymers for Fuel Cells
… uptake, and proton conductivities of random copolymers. Changes in block length, however, have a pronounced effect on multiblock copolymers, affecting surface and bulk morphologies, water uptake, proton conductivity, and hydrolytic stability, suggesting that multiblock copolymer PEM …
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The Influence of Aromatic Disulfonated Random and Block Copolymers' Molecular Weight, Composition,and Microstructure on the Properties of Proton Exchange Membranes for Fuel Cells
… important for obtaining high molecular weight copolymers and accurate control of the oligomer's molecular weight. A novel method to characterize the purity of disulfonated monomer, SDCDPS, was developed by using UV-visible spectroscopy. This allowed for utiliziation of the crude SDCDPS directly …
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Synthesis and Characterization of Linear and Crosslinked Sulfonated Poly(arylene ether sulfone)s: Hydrocarbon-based Copolymers as Ion Conductive Membranes for Electrochemical Systems
… poly(arylene ether sulfone)s as ion conductive copolymers have numerous potential applications. Membranes cast from these copolymers are desirable due to their good chemical and thermal stability, excellent mechanical strength, satisfactory conductivity, and excellent transport properties of …
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Synthesis and Characterization of Multiblock Copolymers for Proton Exchange Membrane Fuel Cells (PEMFC)
Nanophase-separated hydrophilic-hydrophobic multiblock copolymers are promising proton exchange membrane (PEM) materials due to their ability to form various morphological structures which enhance transport. Four arylene chlorides monomers (2,5-Dichlorobenzophenone and its derivatives) were first …
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Effect of Backbone Structure on Membrane Properties for Poly(arylene ether) Random and Multiblock Copolymers
… structure to produce hydrophilic-hydrophobic multiblock copolymers. The hydrophobic segments were based upon poly(arylene ether benzonitrile) polymers and copolymers. The oligomers were synthesized and isolated separately, then reacted under mild conditions to form the alternating multiblock …
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Characterization of Structure-Property Relationships in Hydrophilic-Hydrophobic Multiblock Copolymers for Use in Proton Exchange Membrane Fuel Cells
… of alternative PEMs have been synthesized by copolymerizing various aromatic comonomers, but the smaller ion channels prohibit rapid proton transport under partially hydrated conditions. One solution has been to synthesize multiblock copolymers from hydrophilic and hydrophobic oligomers to …
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Intranasal delivery of therapeutics targeted to CSF and Brain
… are executed subsequently, the use of multiblock copolymer which degrades at mucosal pH was explored as an alternative as well. The gel formulations prolonged the brain levels of cefotaxime as well as CSF levels of ziconotide as well. This project has clearly demonstrated that …
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Synthesis and Characterization of Sulfonated Poly(arylene ether sulfone)s for Membrane Separations
… the presence of calcium, which in the directly copolymerized disulfonated materials is compromised. The post-sulfonated poly(arylene ether sulfone)s showed no compromise in sodium rejection in a mixed-feed of sodium chloride and calcium chloride. In the membrane electrolysis of water, Nafion's …
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Interfacial bioorthogonal chemistry for biomaterials synthesis and patterning and development of catalytic method for "turning-on" the tetrazine ligation
… strategy developed for the synthesis of hybrid multiblock copolymer. Meter-long copolymer fibers were pulled out of interface of two immiscible solutions. The unique modular approach enables the facile incorporation of functional peptides into the copolymer to fine-tune its biological …
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Morphological Characterization and Analysis of Ion-Containing Polymers Using Small Angle X-ray Scattering
… lengths for stilbene and styrenic alternating copolymers range from 2 to 6 nm, which characterizes these copolymers into a class of semi-rigid polymers. This study allows to elucidate the steric crowding effect on the chain stiffness of these polymers, which provides fundamental understanding …
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Synthesis and Characterization of Hydrophobic-Hydrophilic Segmented and Multiblock Copolymers for Proton Exchange Membrane and Reverse Osmosis Applications
… sulfone) hydrophilic-hydrophobic segmented and multiblock copolymers for application as proton exchange membranes (PEMs) in fuel cells or as reverse osmosis (RO) membranes for water desalination. The first objective was to demonstrate that synthesizing blocky copolymers using a one oligomer, two …