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Full-Text Articles in Engineering
Effect Of Carbon Nanotube On Phase Transitions Of Nematic Liquid Crystals, Hatice Duran, Bruce Gazdecki, Atsushi Yamashita, Thein Kyu
Effect Of Carbon Nanotube On Phase Transitions Of Nematic Liquid Crystals, Hatice Duran, Bruce Gazdecki, Atsushi Yamashita, Thein Kyu
Thein Kyu
Phase diagrams of multiwall carbon nanotube (MWNT)/nematic liquid crystal (E7) and bucky ball (C60)/nematic liquid crystal binary systems were investigated by means of optical microscopy and differential scanning calorimetry (DSC). It was found that the isotropic-nematic phase transition temperature of liquid crystal component is enhanced by MWNT. A chimney type phase diagram occur over a narrow range of 0.1-0.2ball/E7 system did not showed any changes of TNI in the same concentration range. This behavior has been attributed to anisotropic alignment of carbon nanotubes and liquid crystal molecules, which is entropic in origin.
Polyolefin Composites, Thein Kyu
Melt-Processable, Toughened, Transparent Blends Of Pc/Pmma, Thein Kyu
Melt-Processable, Toughened, Transparent Blends Of Pc/Pmma, Thein Kyu
Thein Kyu
No abstract provided.
Asymmetric Membranes Formed By Coagulation Induced Phase Separation Of Poly(Vinyl Pyrrolidone)/Poly(Ether Sulfone)/Genistein Blends, Teng Chang, Chandrasekaran Neelakandan, Thein Kyu, Yu-Tsan Tseng, Linda Define, Thomas Alexander
Asymmetric Membranes Formed By Coagulation Induced Phase Separation Of Poly(Vinyl Pyrrolidone)/Poly(Ether Sulfone)/Genistein Blends, Teng Chang, Chandrasekaran Neelakandan, Thein Kyu, Yu-Tsan Tseng, Linda Define, Thomas Alexander
Thein Kyu
Development of asymmetric channel morphology driven by coagulation-induced phase separation of genistein (G) modified poly(ether sulfone)/poly(vinyl pyrrolidone) (PES/PVP) blends has been examined in relation to their miscibility phase diagram. PES/G pairs turned out to be miscible in the amorphous state, whereas solid–liquid phase separation occurred at high genistein compositions. The solid–liquid phase diagram involving the liquidus and solidus lines were computed self-consistently in the framework of the combined free energy of Flory-Huggins for liquid–liquid phase separation and phase field free energy for crystal solidification. The ternary phase diagram of PES/PVP/G blends was subsequently established that consisted of various coexistence regions. …
Liquid Crystalline Polymer Systems: Tech. Advances, Thein Kyu
Liquid Crystalline Polymer Systems: Tech. Advances, Thein Kyu
Thein Kyu
No abstract provided.
Crystal Liquid Crystal Phase Diagrams, Thein Kyu
Incorporation Of Hyperbranched Supramolecules Into Nafion Ionomer Domains Through Impregnation And In-Situ Photopolymerization, Nadzrinahamin Nazir, Thein Kyu, Anna Reinsel, Matthew Espe, Mami Nosaka, Hiruto Kudo, Tadatomi Nishikubo
Incorporation Of Hyperbranched Supramolecules Into Nafion Ionomer Domains Through Impregnation And In-Situ Photopolymerization, Nadzrinahamin Nazir, Thein Kyu, Anna Reinsel, Matthew Espe, Mami Nosaka, Hiruto Kudo, Tadatomi Nishikubo
Thein Kyu
Nafion membranes were impregnated with photocurable supramolecules, viz., hyperbranched polyester having pendant functional carboxylic acid groups (HBPEAc-COOH) by swelling in methanol and subsequently photocured in-situ after drying. Structure-property relationships of the HBPEAc-COOH impregnated Nafion membranes were analyzed on the basis of Fourier transform infrared (FTIR) spectroscopy, solid-state nuclear magnetic resonance (SSNMR) and dynamic mechanical analysis (DMA). FTIR and SSNMR investigations revealed that about 7 wt % of HBPEAc-COOH was actually incorporated into the ionic domains of Nafion. The FTIR study suggests possible complexation via inter-species hydrogen bonding between the carboxylic groups of HBPEAc-COOH and the sulfonate groups of Nafion. The …
Experimental And Theoretical Investigations Of Porous Structure Formation In Electrospun Fibers, Thein Kyu
Experimental And Theoretical Investigations Of Porous Structure Formation In Electrospun Fibers, Thein Kyu
Thein Kyu
The development of internal microstructure in electrospun fibers has been investigated both experimentally and theoretically. Various morphologies such as tubes, beads, and porous structures have been observed experimentally during electrospinning from amorphous polymer solutions such as poly(methyl methacrylate)/methylene chloride and poly(styrene)/tetrahydrofuran. The dynamics of electrospinning is modeled based on multiple virtual strands of beads connected by Maxwell's elements in a cylindrical coordinate system. Concurrently, spatiotemporal growth of the porous structure is calculated in the framework of Cahn−Hilliard time-evolution equation under the quasi steady state assumption coupled with the solvent evaporation rate equation. The coarse-grain simulation reveals the real-time formation of …
Experimental Observation And Phase-Field Modeling Of Interface Morphological Transition In Unidirectional Solidification, Thein Kyu
Thein Kyu
No abstract provided.
Reaction Induced Phase Separation In Blends Of Epoxy And Multifunctional Polybutadiene, Thein Kyu
Reaction Induced Phase Separation In Blends Of Epoxy And Multifunctional Polybutadiene, Thein Kyu
Thein Kyu
The phase behavior and separation dynamics have been investigated in blends of diglycidyl ether of bisphenol A (DGEBA), curing agent methylene dianiline (MDA), and a reactive liquid rubber (R45EPI) through application of differential scanning calorimetry (DSC), one- and two-dimensional light scattering, and optical microscopy. DSC analysis indicates that the system consists of three reactions: the self-condensations of DGEBA and R45EPI, as well as a cross-reaction between the two constituents. Observation of the dynamics of the 50/25.4/50 DGEBA/MDA/R45EPI system reveals that an initial phase separation is governed by the dominant self-curing reaction of DGEBA, followed by a phase dissolution characterized by …
Highly Conductive, Completely Amorphous Polymer Electrolyte Membranes Fabricated Through Photo-Polymerization Of Ply(Ethylene Glycoldiacrylate) Containing Solid Plasticizer And Ionic Liquid Mixtures, Thein Kyu
Thein Kyu
No abstract provided.
Phase Equilibria Of A Mixture Of A Side Chain Liquid Crystalline Polymer And Its Blends With Low Molecular Mass Liquid Crystal, Namil Kim, Jaehyuck Choi, Liang-Chy Chien, Thein Kyu
Phase Equilibria Of A Mixture Of A Side Chain Liquid Crystalline Polymer And Its Blends With Low Molecular Mass Liquid Crystal, Namil Kim, Jaehyuck Choi, Liang-Chy Chien, Thein Kyu
Thein Kyu
A side-chain liquid crystalline polymer based on p-methoxyphenyl-p‘-acryloyloxy benzoate was synthesized for utilization in a polymer dispersed liquid crystal. Phase diagram of the blends of side-chain liquid crystalline polymer and low molecular mass liquid crystal (K21) was established by means of light scattering and differential scanning calorimetry. A theoretical phase diagram was established by self-consistently solving the combined free energy densities of Flory−Huggins, Maier−Saupe, and phase field theory of solidification. The theoretical phase diagram was established to compare with the observed phase diagram of the binary mesogenic mixtures, showing the isotropic, isotropic + nematic (L1 + N2), nematic + nematic …
Impregnation Of Waterwheel Supramolecules As Proton Carrier In Natin Perfluorinated Ionomer Membranes, Thein Kyu
Thein Kyu
No abstract provided.
Cell Viability, Anti-Oxidant And Anti-Inflammatory Properties Of Genistein Modified Polyamide/Poly(Vinyl Pyrrolidone) Dialysis Membranes, Thein Kyu
Thein Kyu
No abstract provided.
Phase Field Modeling On Polymer Crystallization And Phase Separation In Crystalline Polymer Blends, Thein Kyu
Phase Field Modeling On Polymer Crystallization And Phase Separation In Crystalline Polymer Blends, Thein Kyu
Thein Kyu
No abstract provided.
Immunological Response Of Genistein Modified Poly(Vinyl Pyrrolidone)/Poly(Ether Sulfone) Dialysis Membrane In Human Blood, Thein Kyu
Thein Kyu
No abstract provided.
Phase Field Approach To Phase Equilibria And Dynamics Of Phase Separation And Crystallization In Blends Of Polypropylene Isomers And Ethylene Propylene Diene Terpolymer, Thein Kyu
Thein Kyu
No abstract provided.
Effect Of Glucose On Immunological Response Of Polyphenols In Human Blood, Thein Kyu
Effect Of Glucose On Immunological Response Of Polyphenols In Human Blood, Thein Kyu
Thein Kyu
No abstract provided.
Organic And Polymeric Photonic Band Gap Materials And Devices, Thein Kyu
Organic And Polymeric Photonic Band Gap Materials And Devices, Thein Kyu
Thein Kyu
No abstract provided.
Crystal Nucleation And Motion: A New Type Of Growth Instability , Thein Kyu
Crystal Nucleation And Motion: A New Type Of Growth Instability , Thein Kyu
Thein Kyu
No abstract provided.
20. Template Crystallization Of Ultrahigh Molecular Weight Polypropylene Induced By Chain Orientation Of Cocrystallized Ultrahigh Molecular Weight Polyethylene, Domasius Nwabunma, Thein Kyu, Rockliffe Manley
20. Template Crystallization Of Ultrahigh Molecular Weight Polypropylene Induced By Chain Orientation Of Cocrystallized Ultrahigh Molecular Weight Polyethylene, Domasius Nwabunma, Thein Kyu, Rockliffe Manley
Thein Kyu
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Morphology Development In Relation To Ternary Phase Diagram Of Biodegradable Poly(D,L-Lactic Acid)/Poly(E-Caprolactone)/Poly(Ethylene Oxide) Blends, Thein Kyu
Thein Kyu
No abstract provided.
Hydrogen Bonding Interaction And Miscibility Studies Of Amorphous Poly(Amide)/Poly(Vinyl Pyrrolidone) Blends Containing Mangiferin, Chandrasekaran Neelakandan, Thein Kyu
Hydrogen Bonding Interaction And Miscibility Studies Of Amorphous Poly(Amide)/Poly(Vinyl Pyrrolidone) Blends Containing Mangiferin, Chandrasekaran Neelakandan, Thein Kyu
Thein Kyu
Miscibility studies of amorphous poly(amide)/poly(vinyl pyrrolidone) (PA/PVP) blends containing a crystalline phytochemical called “mangiferin” have been carried out using differential scanning calorimetry, Fourier transformed infrared spectroscopy and polarized optical microscopy. The binary blends of PA/PVP prepared from dimethylsulfoxide solutions were found to be completely miscible showing a systematic movement of a single glass transition temperature over the entire composition range. The FTIR study indicated the occurrence of cross-hydrogen bonding interactions between PA and PVP, which may be responsible for complete miscibility of the PA/PVP pair. Moreover, cross-hydrogen bonding promotes miscibility in binary blends of PA/mangiferin and PVP/mangiferin. However, the addition …
Phase Equilibira And Photopolymerization Induce Phase Transitions Of Mesogenic Diacrylate Monomer And Low Molecular Mass Liquid Crystal Mixtures, Namil Kim, Thein Kyu
Phase Equilibira And Photopolymerization Induce Phase Transitions Of Mesogenic Diacrylate Monomer And Low Molecular Mass Liquid Crystal Mixtures, Namil Kim, Thein Kyu
Thein Kyu
Experimental phase diagrams of binary mesogenic mixtures of reactive mesogenic diacrylate (RM257) monomer and low molar mass liquid crystals (E7) were determined by means of differential scanning calorimetry and optical microscopy. The combined free energy densities of Flory–Huggins for liquid–liquid demixing, Maier–Saupe for nematic ordering, and phase field free energy for crystal solidification was proposed to describe the phase diagrams of the starting E7/RM257 mixtures. The phase diagram thus constructed is an ideal mixing type, exhibiting a narrow loop of isotropic + nematic (I + N) coexistence region followed by the crystal + nematic (Cr1 + N) region in descending …
Polyolefin Blends, Thein Kyu
Influence Of Photo-Polymerization Reaction Kinetics On Diffraction Efficiency Of H-Pdlc Undergoing Pattern-Photolithographic Reaction In Mixtures Of Acrylic Monomer/Nematic Liquid Crystals, Thein Kyu
Thein Kyu
No abstract provided.
Modeling Particle Inflation From Poly(Amic Acid) Powdered Precursors (Part Ii): Morphological Development During Bubble Growth, Camilo Cano, Meaghan Clark, Thein Kyu, R. Pipes
Modeling Particle Inflation From Poly(Amic Acid) Powdered Precursors (Part Ii): Morphological Development During Bubble Growth, Camilo Cano, Meaghan Clark, Thein Kyu, R. Pipes
Thein Kyu
The morphological development of cellular polyimide microstructures from poly(amic acid) powders has been shown to depend on the processing conditions throughout the inflation process and the morphological characteristics of the precursor particles. In an earlier publication the authors presented a numerical study of the preliminary stages prior to particle inflation when the processing temperature is below the glass transition temperature, Tg. In the present article, a second numerical scheme is presented for behavior above Tg in which bubble growth is modeled to account for the effect of multiple phenomena in the final stages of morphological development. The bubble growth kinematics …
Dynamics And Morphology Development In Electrospun Fibers Driven By Concentration Sweeps, Pratyush Dayal, Thein Kyu
Dynamics And Morphology Development In Electrospun Fibers Driven By Concentration Sweeps, Pratyush Dayal, Thein Kyu
Thein Kyu
The present article describes the modeling and simulation of the dynamics of the electrospinning process coupled with the spatio-temporal evolution of fiber morphology driven by concentration sweeps. The electrospinning process has been modeled based on an array of beads connected by Maxwell's elements in a cylindrical shell to describe the force balance between Coulombic and viscoelastic forces at the surface of the jet. The phase separation dynamics has been calculated in the framework of the Cahn-Hilliard time-evolution equation by incorporating Flory-Huggins free energy for liquid-liquid demixing in conjunction with solvent evaporation through the fiber surface. The simulations based on the …
Phase Dissolution In A Liquid-Crystalline Polymer-Solution, T Kyu, Z. Ping, P. Mukherjee
Phase Dissolution In A Liquid-Crystalline Polymer-Solution, T Kyu, Z. Ping, P. Mukherjee
Thein Kyu
No abstract provided.
Phase-Separation Dynamics Of A Polymer-Dispersed Liquid-Crystal, Thein Kyu, I Ilies, M Mustafa
Phase-Separation Dynamics Of A Polymer-Dispersed Liquid-Crystal, Thein Kyu, I Ilies, M Mustafa
Thein Kyu
Phase separation in a polymer dispersed liquid crystal (PDLC), consisting of a main chain liquid crystal (E7) and polymethyl methacrylate (PMMA), was studied by means of light scattering and optical microscopy. The PMMA/E7 mixture exhibits an upper critical solution temperature (UCST), overlapping with a nematic-isotropic transition of the E7 liquid crystal. Several temperature quenches were undertaken by rapidly transferring the 60/40 PMMA/E7 from a single phase (95-degrees-C) to an unstable region (25, 35 and 45-degrees-C) and by subsequently monitoring the time-evolution of scattering profiles. The time-evolution of structure factor reveals a cross-over of a kinetic exponent from -0.33 to -0.6 …