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Full-Text Articles in Physics
Effect Of Trans-Cis Photoisomerization On Phase Equilibria And Phase Transition Of Liquid-Crystalline Azobenzene Chromophore And Its Blends With Reactive Mesogenic Diacrylate, Namil Kim, Quan Li, Thein Kyu
Effect Of Trans-Cis Photoisomerization On Phase Equilibria And Phase Transition Of Liquid-Crystalline Azobenzene Chromophore And Its Blends With Reactive Mesogenic Diacrylate, Namil Kim, Quan Li, Thein Kyu
Thein Kyu
Photoisomerization-induced phase transition of neat liquid-crystalline azobenzene chromophore (LCAC) and its effect on phase diagrams of its mixtures with reactive mesogenic diacrylate monomer (RM257) have been investigated experimentally and theoretically. Upon irradiation with ultraviolet light, the nematic phase of LCAC transformed to isotropic, while the crystal phase showed corrugated textures on the surface (i.e., ripples). The phase-transition temperatures and corresponding morphologies of the blends have been investigated by means of differential scanning calorimetry and optical microscopy. A theoretical phase diagram of a binary nematic and crystalline system was constructed by self-consistently solving the combined free energies of Flory-Huggins, Maier-Saupe, and …
Spatio-Temporal Growth Of Nematic Domains In Liquid Crystal Polymer Mixtures, Hao-Wen Chiu, Thein Kyu
Spatio-Temporal Growth Of Nematic Domains In Liquid Crystal Polymer Mixtures, Hao-Wen Chiu, Thein Kyu
Thein Kyu
Dynamics of phase separation and morphology development in mixtures of a low molar mass liquid crystal (LC) and a polymer have been investigated theoretically in comparison with experimental results. In the theoretical model, the combined free-energy densities of Flory-Huggins theory for isotropic mixing and Maier-Saupe theory for nematic ordering have been incorporated into the time-dependent Ginzburg-Landau equation (type C). The temporal evolution of the structure factor and the emergence of phase-separated liquid crystal domains have been simulated on the basis of an explicit central difference method based on a square lattice (128 x 128) with a periodic boundary condition. Of …
Phase Diagrams Of A Binary Smectic-A Mixture, Hao-Wen Chiu, Thein Kyu
Phase Diagrams Of A Binary Smectic-A Mixture, Hao-Wen Chiu, Thein Kyu
Thein Kyu
A variety of smectic phase diagrams involving smectic-isotropic and smectic-nematic-isotropic transitions have been calculated based on a combination of Flory-Huggins (FH) theory for isotropic mixing and Maier-Saupe-McMillan (MSM) theory for smectic-A ordering of liquid crystals (LC). To describe the mesophase transitions, two nematic order parameters and two smectic order parameters have been coupled through the normalized orientation distribution and partition functions. Flory-Huggins interaction parameter (chi) for isotropic mixing and the coupling term involving the nematic interaction parameter (nu) and the McMillan smectic interaction parameter (alpha) for phase transitions of liquid crystals have been incorporated in the calculation. The predictive capability …
Compatibility Of Elastomers With Refrigerant Lubricant Mixtures, Gary Hamed, R. Seiple
Compatibility Of Elastomers With Refrigerant Lubricant Mixtures, Gary Hamed, R. Seiple
Gary R. Hamed
No abstract provided.
Observation Of Novel Liquid-Crystalline Phase Above The Bulk-Melting Temperature, Keshav Gautam, Satyendra Kumar, Didier Wermeille, Doug Robinson, Ali Dhinojwala
Observation Of Novel Liquid-Crystalline Phase Above The Bulk-Melting Temperature, Keshav Gautam, Satyendra Kumar, Didier Wermeille, Doug Robinson, Ali Dhinojwala
Ali Dhinojwala
In this paper, we show that a noncrystalline but ordered smectic-like phase exists above the bulk-melting temperature (T-m) at poly(n-alkyl acrylates)-air interface. The surface ordered phase is one monolayer thick and undergoes a sharp transition from order to disorder 10degreesC above T-m for n=22. The presence of a surface phase that does not exist in the bulk has important implications in the design of thermally responsive adhesives.
Statistical Mechanics Of Wormlike Polymers From A New Generating Function. Ii. The Force-Elongation Relationship, Gustavo Carri
Statistical Mechanics Of Wormlike Polymers From A New Generating Function. Ii. The Force-Elongation Relationship, Gustavo Carri
Gustavo A. Carri
No abstract provided.
Statistical Mechanics Of Worm-Like Polymers From A New Generating Function, Gustavo A. Carri, Marcelo Marucho
Statistical Mechanics Of Worm-Like Polymers From A New Generating Function, Gustavo A. Carri, Marcelo Marucho
Gustavo A. Carri
We present a mathematical approach to the worm-like chain model of semiflexible polymers. Our method is built on a novel generating function from which all the properties of the model can be derived. Moreover, this approach satisfies the local inextensibility constraint exactly. In this paper, we focus on the lowest order contribution to the generating function and derive explicit analytical expressions for the characteristic function, polymer propagator, single chain structure factor, and mean square end-to-end distance. These analytical expressions are valid for polymers with any degree of stiffness and contour length. We find that our calculations are able to capture …