Three different kinds of siloxane-containing polybenzamide copolymers have been prepared: a series of siloxane-containing segmented copolymers; a siloxane-poly(benzamide) random copolymer; and a poly(benzamide) - poly...
Three different kinds of siloxane-containing polybenzamide copolymers have been prepared: a series of siloxane-containing segmented copolymers; a siloxane-poly(benzamide) random copolymer; and a poly(benzamide) - poly(dimethylsiloxane) block copolymer. The structures of these copolymers were confirmed using diffuse reflectance FTIR spectroscopy. Dilute solution viscometery showed them to be high polymers. The thermal stabilities of these copolymers were studied using thermal gravimetric analysis. Incorporation of siloxane units via a phenyl link was found to not affect the inherent thermal stability of the poly(benzamide) chain. The solution phase behavior of these copolymers in DMAC/LiCl was studied using an optical microscope fitted with cross-polars. The segmented copolymers and the block copolymer exhibited lyotropic behavior, which was influenced by the amount of siloxane and the overall molecular architecture. Solutions of the random copolymer were isotropic at all concentrations studied.
The electrophosphorescent OLED with heterostructured (mixed) light emission layer was characterized. Base on the best combination profile of mixed emitter obtained, we have fabricated the white OLEDs, where the select...
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A series of new poly(enaminonitriles) were synthesized by the condensation polymerization of three different bis(chlorodicyano-vinyl) aromatic monomers with various aromatic diamines. These polymers have moderate to h...
A series of new poly(enaminonitriles) were synthesized by the condensation polymerization of three different bis(chlorodicyano-vinyl) aromatic monomers with various aromatic diamines. These polymers have moderate to high molecular weight with intrinsic viscosities ranging from 0.35 to 0.77 dl/g and form flexible films. These polymers exhibit good solubility in many organic solvents and excellent thermal stability, retaining their weight up to 400 °C in air. Poly(enaminonitriles) undergo ‘curing’ reactions at high temperature (~300 °C) to provide insoluble, infusible material without emission of volatile by-products. Dielectric constants of these polymers ranged from 3.5 to 5.2 depending on the structure. Their thermal and dielectric properties are correlated to the structures.
An A/B block copolymer consists of two macromolecules bonded together. In forming an equilibrium structure, such a material may separate into distinct phases, creating domains of component A and of component B. A domi...
An A/B block copolymer consists of two macromolecules bonded together. In forming an equilibrium structure, such a material may separate into distinct phases, creating domains of component A and of component B. A dominant factor in the determination of the domain morphology is area-minimization of the intermaterial surface, subject to fixed volume fractions. Surfaces that satisfy this mathematical condition are said to have constant mean curvature. The geometry of such surfaces strongly influences material physical properties. We have discovered domain structures in microphase-separated diblock copolymers that closely approximate periodic surfaces of constant mean curvature. Transmission electron microscopy and computer-simulation are used to deduce the three dimensional microstructure by comparison of tilt series with two-dimensional image projection simulations of three-dimensional mathematical models. Two structures are discussed: First is the double diamond microdomain morphology, associated with a newly discovered family of triply periodic constant mean curvature surfaces. Second, a doubly periodic boundary between lamellar microdomains, corresponding to a classically known minimal surface (Scherk’s First Surface), is described.
Tetraphenylethene derivatives [Ph(PhCH=CHPhR)C=C(PhCH=CHPhR)Ph, R=H, CN, NO2, NPh2] with green, yellow-green, and orange emission colours were designed and synthesized. These molecules are practically non-emissive in ...
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The lithium aluminum titanium phosphate (LATP)/Polyacrylonitrile (PAN) composite fiber-based membrane were prepared by electrospinning composite solution of LATP and PAN in N, N-dimethylformamide(DMF). The crystalliza...
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ISBN:
(纸本)9787122120199
The lithium aluminum titanium phosphate (LATP)/Polyacrylonitrile (PAN) composite fiber-based membrane were prepared by electrospinning composite solution of LATP and PAN in N, N-dimethylformamide(DMF). The crystallization phase of the LATP particles were characterized by X-ray diffraction(XRD). The electrolyte uptakes of the electrospun LATP/PAN composite fiber-based membranes were also evaluated. In addition, the electrochemical performance of the liquid electrolyte-soaked electrospun LATP/PAN composite fiber-based is also improved after the introduction of LATP particles.
Organic Thin Film Transistors (OTFTs) are promising devices for future development of variety of low-cost and large-area electronics applications such as flexible displays. This paper analyzes the performance of OTFT ...
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Orthopedic procedures often require repair materials that can carry large loads without excessive deformation or failure. To this end, we designed composites using two biocompatible/bioabsorbable polymers, poly(L-lact...
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Orthopedic procedures often require repair materials that can carry large loads without excessive deformation or failure. To this end, we designed composites using two biocompatible/bioabsorbable polymers, poly(L-lactic acid) (PLLA) and polycaprolactone (PCL). The latter was filled with nano-needles of hydroxyapatite (HA), while the PLLA was used in long-fiber form. Theory advises that the HA nano-needles must be of high aspect ratio and be aligned in the matrix to gain sufficient stiffness. We have explored several processing techniques for accomplishing this task, and have successfully made composites in the 8-to 10-GPa range. Variations of this structure will also be described.
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