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Showing 1 to 20 of 128 for “"microphase"”.
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Toward commercializable microphase-separating copolymer electrolytes for rechargeable lithium batteries
Microphase-separating copolymers have been shown to possess the electrical properties of a polymer liquid and the mechanical properties of a solid. In the past, these materials had to be produced via anionic methods that are not easily scalable. To circumvent this problem, two approaches were …
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Catalytic properties of palladium nanocluster synthesized within microphase-separated diblock copolymers
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1997.
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Microphase Separation Studies in Styrene-Diene Block Copolymer-based Hot-Melt Pressure- Sensitive Adhesives
… melt. The work also focuses on determining the microphase separation mechanism in adhesive melts containing various amounts of low molecular weight resin (tackifiers) blended with styrene — diene block copolymers. To understand the correlation between adhesive morphology and their dynamic …
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Mesostructuring of SiCN Materials and Catalysts via Microphase Separation Technique utilizing High-Density Polyethylene Blocks
… (PEOPL) copolymer by microphase separation technique and selective etching of polylactide block.1H NMR was used to confirm the formation of copolymer. Atomic Force Microscopy (AFM) was used to analyse the microphase separated PEOPL copolymer. The progress of etching …
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Thermal and Morphological Study of Segmented Multiblock Copolyesters Containing 2,2,4,4-Tetramethyl-1,3-cyclobutanediol
… of 160 °C and above led to increased microphase mixing. The small angle X-ray scattering studies confirmed the microphase separated morphology of copolyesters and supported the argument of increased microphase mixing in copolyesters annealed at higher temperatures. The amount of …
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Structure–Property Relationships Of: 1) Novel Polyurethane and Polyurea Segmented Copolymers and 2) The Influence of Selected Solution Casting Variables on the Solid State Structure of Synthetic Polypeptide Films Based on Glutamate Chemistry
… that are typically used to promote a microphase separated morphology that gives these materials their useful characteristics. Polyurethanes in which a single asymmetric diisocyanate comprising the whole of the hard segment were found to display poor microphase separation. Conversely, …
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Gas permeability of polyimide/polysiloxane block copolymers
… alternating polyimide/ poly(dimethylsiloxane) microphase separated block copolymers ranging from 0-50 wgt. % poly(dimethylsiloxane) have been measured for permeability characteristics. The polyimide segment of the copolymers was based on oxydiphthalicdianhydride (ODPA) and 1,4-Bis(4-amino-1,1- …
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Shape and chemically anisotropic colloidal particles: A theoretical study of their structure, phase behavior, and slow dynamics
… fluid, macrophase separated, attraction driven microphase separated, repulsion driven microphase separated and crystalline regimes. Macrophase separation is predicted in highly attractive low volume fraction systems. Attraction driven microphase separation is charaterized by long length scale …
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Fundamental adhesive studies of block copolymers
… their adhesive properties. The structure of the microphase separated morphology of the materials studied was found to influence the adhesive behavior in applications as hot melt/structural type adhesives and as pressure sensitive adhesives. The thermal and the dynamic mechanical behavior of …
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Self assembly of block copolymers : applicability in microelectronics and gains for patterned media
… do just that. An immiscible block copolymer will microphase separate into individual domains due to unfavorable mixing enthalpy. These microphase-separated blocks can have domain sizes of very low dimensions, to the order of 15-20 nms. By careful preparation, microphase-separated thin films of …
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Advancing Step-Growth Polymers: Novel Macromolecular Design and Electrostatic Interactions in Polyesters and Polyurethanes
… uncovered unique needle-like, interconnected, microphase separated surface morphologies, and small-angle X-ray scattering confirmed the presence of bulk microphase separation. This new synthetic strategy enabled selective control of ionic charge placement into the hard segment or soft segment …
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Engineering properties of multiphase block copolymers
… of block copolymers is their ability to undergo microphase separation above a critical block length. Either one or two phase block copolymers can be prepared by controlling the molecular weights of the parent oligomers. In the bisphenol-A polycarbonate/bisphenol-A polysulfone system, for example, …
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Explorations in Supramolecular Chemistry: Part 1. Development of a Modular System for the Study of Self-Organization Through Microphase Segregation in Discotic Liquid Crystals. Part 2. Investigation of Deazapterins and Naphthyridines as End-Groups for Supramolecular Polymers
In the second investigation, the use of multiple highly directional hydrogen bonds for the formation of supramolecular polymers was explored. Synthetic routes toward supramolecular polymer end-groups based upon the 2-amino-5-deazapterin and 2,7-diamino-[1,8]-naphthyridine ring systems were pursued. …
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Composite cathodes for lithium rechargeable batteries
… the electrode-active material. Copolymers of microphase-separating rubbery block and graft copolymers, previously developed as solid electrolytes, provide a matrix for directing the synthesis of an inorganic battery-active phase. The copolymers include poly[(oxyethylene)9 …
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Dynamics of liquids in porous media: Investigating competitive adsorption using NMR relaxometry
… to investigate competitive adsorption and microphase separation of liquid mixtures imbibed within porous media. The work was done on three different mesoporous catalysts and catalyst supports, namely anatase titania, γ-alumina and silica. The main NMR relaxometry method that was applied was …
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Block copolymers containing charge transport groups and semiconductor nanoclusters : synthesis, characterization, and optoelectronic applications
… copolymer were prepared, which exhibited eithe; microphase separated or nonmicrophase separated morphologies depending on the choice of casting solvent. Charge transfer complex formation was observed in the diblocks, and the extent of complex formation was found to be greater in the nonmicrophase …
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Donor-Acceptor Block Copolymers for Charge Separation at Nanostructured Interfaces
… block copolymers. Block copolymers exhibit microphase separation with domain sizes on a nanometer scale by the interplay between immiscibility and molecular connectivity. I used a controlled radical polymerization technique, the nitroxide mediated radical polymerization (NMRP), to get block …
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Characterization of block copolymers and polymer blends by inverse gas chromatography
… Gas Chromatography (IGC) to characterize the microphase structure of block copolymers, and the strength of the thermodynamic interactions between the components of polymer blends and the unlike segments of block copolymers was examined. There were three parts to the study. First, the Scott …
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Bio-inspired Design and Self-Assembly of Nucleobase- and Ion-Containing Polymers
… triblock polymer architecture drove microphase-separation into a physically crosslinked hard phase in a low Tg matrix. Hydrogen bonding in the hard phase enhanced the mechanical strength and maintained processability of microphase-separated copolymers for thermoplastics and …
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