Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 26 for “"Multiblock copolymers"”.
-
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 …
-
Synthesis and Characterization of Hydrophobic-Hydrophilic Multiblock Copolymers for Proton Exchange Membrane Applications
… partially fluorinated/sulfonated multiblock copolymers were synthesized and characterized in this thesis. The hydrophilic blocks were based upon the nucleophilic step polymerization of 3, 3′-disulfonated, 4, 4′-dichlorodiphenyl sulfone (SDCDPS) with an excess 4, 4′-biphenol (BP) to …
-
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 …
-
Synthesis and Properties of Novel Triptycene-containing Segmented Polyurethanes and Semicrystalline Polysulfone-polyester Multiblock Copolymers
Segmented copolymers are important polymers with attractive properties and wide applications. In this dissertation, segmented polyurethanes containing triptycene units and multiblock copolymers containing poly(arylene ether sulfone) (PAES) and poly(1,4-cyclohexyldimethylene terephthalate) (PCT) …
-
Characterization of Structure-Property Relationships in Hydrophilic-Hydrophobic Multiblock Copolymers for Use in Proton Exchange Membrane Fuel Cells
… conditions. One solution has been to synthesize multiblock copolymers from hydrophilic and hydrophobic oligomers to ensure sufficient ion channel size. Four multiblock systems were synthesized from hydrophobic and hydrophilic oligomers and were characterized in this thesis. The first multiblock …
-
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 …
-
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 …
-
Synthesis and Characterization of Hydrophobic-Hydrophilic Multiblock Copolymers for Proton Exchange Membrane and Segmented Copolymer Precursors for Reverse Osmosis Applications
… is to synthesize hydrophobic-hydrophilic multiblock copolymers with high Ion exchange capacity (IEC) values to ensure sufficient ion channel size. In this thesis two multiblock systems were synthesized incorporating trisulfonated hydrophilic oligomers and were characterized in the first …
-
Synthesis and Characterization of Hydrophilic-Hydrophobic Disulfonated Poly(Arylene Ether Sulfone)-Decafluoro Biphenyl Based Poly(Arylene Ether) Multiblock Copolymers for Proton Exchange Membranes (PEMs)
Hydrophilic/hydrophobic block copolymers as proton exchange membranes (PEMs) has become an emerging area of research in recent years. Three series of hydrophilic/hydrophobic, fluorinated/sulfonated multiblock copolymers were synthesized and characterized in this thesis. These copolymers were …
-
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 …
-
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 …
-
Membranen aus [(A)n(B)m]x-Multiblockcopolymeren für den Einsatz in der Direkt-Methanol-Brennstoffzelle (DMFC)
Aramide and arylene ether multiblock copolymers of (AB)n-type with various degrees of sulfonation have been prepared for use in direct methanol fuel cells.
-
Structure Property Relationships of Proton Exchange Membranes
… properties. Most of the hydrocarbon based random copolymers reported in the literature show reduced proton conductivity at low water content. This was attributed to the formation of an isolated morphology. Over the last few years our group has synthesized thermally stable multiblock copolymers …
-
Chemical and Physical Modifications of Semicrystalline Gels to Achieve Controlled Heterogeneity
… and low cost. Specifically, sulfonated multiblock copolymers are attractive because their phase-separated morphologies aide in facile proton transport. In this work, the functionalization of semicrystalline gels of poly(ether ether ketone) (PEEK) is explored as a novel …
-
Liquid State Theory of Equilibrium Structure and Thermodynamics of Block Copolymer Melts and Solutions
… the thermodynamics and structures of fluids of multiblock polymers both with nonpolar and strongly attracting groups. The physical clustering/aggregation process is probed via the calculation of small and wide angle scattering patterns, real space intermolecular radial distribution functions, …
-
Synthesis and Characterization of Poly(siloxane imide) Block Copolymers and End-Functional Polyimides for Interphase Applications
… poly(ether amic acid)s and poly(siloxane imide) multiblock copolymers, comprised of 2,2'-Bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) / meta-phenylene diamine (MPDA) and hexafluoroisopropylidene-2-bis(phthalic acid anhydride) (6FDA) / meta-phenylene diamine (MPDA) polyimide …
-
Mesoscale simulation of block copolymer phase separation and directed self-assembly processes: Applications for semiconductor manufacturing
… accurate results. A short study on the effect of multiblock copolymers on the location of the order-disorder transition was also carried out and it was found that multiblock copolymers had small effect on the ODT. The distribution of chain conformations was also calculated.
-
Statistical mechanical theory of equilibrium structure and miscibility of polymer nanocomposites: effects of polymer chemical heterogeneity and architecture, and nanoparticle surface corrugation and softness
… polymer chemical heterogeneity via the use of AB copolymers offers additional control over the equilibrium structure. Specifically, two types of copolymers are considered – (1) random copolymers (RCP) of disordered sequence and (2) ordered, alternating multiblock copolymers (MBCP). Quantum …
-
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 …
-
Synthesis and Characterization of Sulfonated Poly(arylene ether sulfone)s for Membrane Separations
… electrode stability. Hydrophilic-hydrophobic multiblock copolymers based on disulfonated and non-sulfonated poly(arylene ether sulfone) oligomers feature a lower gas permeability. Various multiblock compositions and casting conditions were investigated and transport properties were …
Page 1 of 2