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Gin, D. L.; Bara, J. E.; Noble, R. D.; Elliott, B. J. “Polymerized Lyotropic
Liquid Crystal Assemblies for Membrane Applications,”
Macromol. Rapid Commun.
2008, 29 (5).
Pecinovsky, C. S.; Hatakeyama, E. S.; Gin. D. L. “Polymerizable Photochromic
Macrocyclic Metallomesogens: Design
of Supramolecular Polymers with Responsive Nanopores,”
Adv. Mater. 2008,
20 (1).
Zhou, M.; Nemade, P. R.; Lu, X.; Zeng, X.; Hatakeyama, E. S.; Noble, R. D.; Gin, D. L., “New Type of Membrane Material for Water Desalination Based on a Cross-linked Bicontinuous Cubic Lyotropic Liquid Crystal Assembly,” J. Am. Chem. Soc. 2007, 129 (31), 9574–9575.
Bara, J. E.; Lessmann, S.; Gabriel, C. J.; Hatakeyama, E. S.; Noble, R. D.; Gin, D. L., “Synthesis and Performance of Polymerizable Room Temperature Ionic Liquids as Gas Separation Membranes,” Ind. Eng. Chem. Res. 2007, 46 (16).
Bara, J. E.; Gabriel, C. J.; Lessmann, S.; Carlisle, T. K.; Finotello, A.; Gin, D. L.; Noble, R. D., “Enhanced CO2 Separation Selectivity in Oligo (ethylene glycol) functionalized Room Temperature Ionic Liquids,” Ind. Eng. Chem. Res. 2007,46 (16).
Karp. E.; Pecinovsky, C. S.; McNevin, M. J.; Gin, D. L.; Schwartz, D. K., “Langmuir Monolayers of a Photo-isomerizable Macrocycle Surfactant,” Langmuir 2007, 23 (15).
Klinkel, K. L.; Kiemele, L. A.; Gin, D. L.; Hagadorn, J. R., "Effect of Ligand Modifications and Varying Metal-to-Ligand Ratio on the Catalyzed Hydrolysis of Phosphorus Triesters by Bimetallic Tetrabenzimidazole Complexes," J. Mol. Catal. A: Chem. 2007, 267.
Bara, J. E.; Kaminski, A. K,; Noble, R. D.; Gin, D. L., “Influence of Nanostructure on Light Gas Separations in Cross-linked Lyotropic Liquid Crystal Membranes,” J. Membr. Sci. 2007, 288.
Cain, N.; van Bogaert, J.; Gin, D. L.; Hammond, S. R.; Schwartz, D. K., "Self-organization of a Wedge-shaped Surfactant in Monolayers and Multilayers," Langmuir, 2007, 23
(2).
One of the frontiers in materials chemistry is the architectural control of synthetic materials on the nanometer-scale. Nanometer-scale architecture is primarily responsible for the impressive properties of many biological structural materials (e.g., bone) and the unique reactivity of many inorganic supercage catalysts (e.g., zeolites). Unfortunately, very few techniques for constructing man-made materials offer compositional or architectural control on this size regime. One of the principal questions that we are addressing is whether materials with unique or superior bulk properties would result if nanometer-scale architectural control could be achieved with modern engineering components.
Over the past eight years, my group and I have developed a successful research program directed at constructing functional materials with controlled nanostructures by designing self-organizing monomers based on thermotropic and lyotropic (i.e., amphiphilic) liquid crystals (LCs). LCs are molecules that self-assemble into organized phases that are intermediate between crystalline solids and isotropic liquids. In these mesophases, the molecules are dynamic and behave like a viscous fluid, while still maintaining a degree of order reminiscent of a crystalline solid. LCs may adopt various phases, depending on (1) the temperature (i.e., thermotropic LCs) or (2) their concentration in a solvent such as water (i.e., lyotropic or amphiphilic LCs) (Figure 1). Through molecular design, we have been able to incorporate functional properties into the LC assemblies and subsequently polymerize them into robust polymer networks with preservation of their nanostructure. These ordered matrices serve as the basis for our new materials synthesis, as well as a platform for investigating structure–property relationships on this size regime. These new LC monomers and assemblies also serve as novel platforms for examining the effect of nanostructure on polymerization kinetics, connectivity, etc., in addition to functional properties.
Figure 1. Common Thermotropic and Lyotropic Liquid Crystalline Phases.
The goals of our research program are fundamental in concept and applied in their long range perspective. We are interested not only in the design of organic monomers with self-assembly properties but also intensely interested in the effects of engineered order on their useful bulk properties. We endeavor to tailor our chemistry to provide control over nanoarchitecture, chemical composition, and processing in our new materials. These factors are crucial if these strategies are to evolve into viable technologies. In order to accomplish these goals, we have taken the approach of initially designing relatively simple molecules to test fundamental concepts such as (1) the viability of polymerizing certain LC assemblies, and (2) whether these assemblies are capable of enhancing or modifying particular properties. Once these proofs of concept have been demonstrated, our subsequent goal is the design of more elaborate building blocks to more thoroughly probe chemical behavior on this size regime.
