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Spatio-temporal emergence of mesomorphic patterns in mixtures of rigid rod and liquid crystalline polymers, DMR 02-09272 Thein Kyu, University of Akron, Akron, Ohio.
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Spatio-temporal emergence of mesomorphic patterns in mixtures of rigid rod and liquid crystalline polymers, DMR 02-09272 Thein Kyu, University of Akron, Akron, Ohio The feasibility of forming cellular arrays in a film containing dendrimer/acrylate monomer mixture by four-wave interference photolithography has been demonstrated. With appropriate functionalization of the dendrimer, such polymeric membranes may find some potential applications including sensors for hazardous gases, chemicals, and bio-hazard substances. Optical micrograph (upper) and atomic force microscopic picture (lower) showing the micron-sized cellular arrays of the cured monomer/dendrimer composite film. 5 m Chemical structures of 16-arm dendrimer (upper) and ethoxylated bisphenol-A diacrylate monomer (Sartomer SR602) (lower) used in the interference photolithography.
Broader Impact: The pattern forming aspects of mesophase structures in soft matters share a common ground with phase transitions and solidifications of small molecule systems such as organic crystals, metal alloys, and biological substances. Education:The PI has been collaborating with Akron Global Polymer Academy (AGPA directed by Mr. Charles Person) in the development of remote controlled experimentation of small-angle light scattering (SALS) as part of a distance learning program. This SALS instrument is intended to use for monitoring diffraction efficiency of photonic crystals during photolithographic polymerization as well as electro-optical switching. The electrically switchable holograms are being made for demonstration to the high school teachers participating in the AGPA program. Personnel:Four graduate students (Greg Yandek, Pratyush Dayal, Rushi Matkar, and Ms. Soojeong Park) are involved in this project in 2004-2005. Dr. Yandek graduated in May, 2005 and now working at the Naval Air Warfare Center, China Lake, California. Mr. Dayal has been involved in the study of “Morphology Development in Electro-Spinning subjected to Solvent Evaporation.” Mr. Matkar’s dissertation research is focused on the determination of “Phase Equilibrium and Phase Transitions in Binary Crystalline Polymer Blends”. Both Ph. D. Candidates are expected to graduate in December 2005. Ms. Park, a junior Ph. D. candidate, is studying on “Spatio-temporal Evolution of Gradient Interface Morphology under Thermal and Light Intensity Gradients during Thermal- and Photo-initiated Polymerization.” National and International Collaboration:The PI is collaborating with Dr. Tim Bunning’s group at the Wright-Patterson Air Force Base on polymer photonic crystals.Internal collaborations have been undertaken with Professor D. Renecker, Department of Polymer science at the University of Akron in the area of electro-spinning and also with Professor G.X. Wang of the Department of Mechanical Engineering in directional crystal solidification. The PI has been collaborating with Dr. Leonid Manevitch of Semenov Institute of Chemical Physics, Moscow, Russia, in the field of phase stability of heterogeneous systems and solitary wave propagations in polymer crystals.