Design and synthesis of multifunctional amphiphilic polymers to tailor the properties of aqueous-liquid crystal interfaces.

摘要

The research described in this thesis is focused on characterization of the assembly and behavior of multifunctional, amphiphilic polymers at interfaces created between thermotropic liquid crystals (LCs) and immiscible aqueous phases. This work aims to provide a basis for general and versatile strategies to engineer the properties of aqueous-LC interfaces and design polymer/liquid crystalline systems that are responsive to a broad range of environmental stimuli. The results presented in this thesis demonstrate that comb-type, random copolymers bearing both hydrophobic and hydrophilic side chain functionality can assemble at aqueous-LC interfaces. Assembly was achieved using one of two approaches: (i) by spontaneous adsorption of water-soluble polymers from bulk aqueous phases to LC interfaces or (ii) by Langmuir-Schaefer transfer of water-insoluble polymers from aqueous-air interfaces to aqueous-LC interfaces. Further, results demonstrate that appropriately designed polymer-laden aqueous-LC interfaces can be responsive and that ordering transitions in the LCs can be triggered by changes to the properties of the aqueous environment (e.g., pH) or by the formation of polymer-polymer complexes at LC interfaces.;As part of developing a general approach to tailor the properties of LC interfaces, this work aims to understand the manner in which the structure and organization of polymers and polymer conjugates at aqueous-LC interfaces influences the ordering of the LCs. For example, results presented in this thesis demonstrate that long-range ordering of polymer chains within thin polymer films at aqueous-LC interfaces leads to uniform alignment of the LCs. An additional study demonstrated that the incorporation of polymer-lipid conjugates into monolayers of phospholipids at LC interfaces has profound effects on the organization of the phospholipid layer and the orientation of the LCs.;Finally, the approaches used to synthesize the novel materials described in this thesis are highly modular in nature and provide general methods to introduce a broad range of functionality (e.g., aliphatic moieties, ionic groups, peptides, carbohydrates, etc.) into the polymer backbone. Thus, the results of this research suggest new principles and approaches to tailor the properties of LC interfaces and design platforms to report on the presence of specified chemical or biological analytes in real-time.