| Self-assembled materials frequently have structures that could make them useful as high-performance, nanostructured materials, but the non-covalent nature of the aggregates makes them sensitive to environmental changes such as in temperature or composition. Our approach to designing nanostructured materials is to take advantage of the self-assembly of lyotropic liquid crystals (LLCs) to generate nanometer-scale structures and to then lock that structure in by polymerization to create a much more robust, cross-linked structure, as has been demonstrated previously in the inverse hexagonal phase (H II). The extension of this approach to other mesophases, specifically the regular hexagonal (HI) and bicontinuous cubic (QII), would provide materials with complementary and potentially superior properties to those derived from the HII phase.;The successful development of polymerizable amphiphiles for the in-phase polymerization of the HI and QII phases was an iterative process that started with a series of analogs to commercially available surfactants that are known to adopt the desired LLC phases. The design and synthesis of these (meth)acryloxy alkyltrimethylammonium bromides as well as their LLC phase behavior is described in Chapter 2. Additionally, an argument is made for the potential causes of the disappointing phase behavior in these molecules. The nature of the headgroup and the polymerizable moiety were identified as the most likely candidates for alteration in order to improve LLC behavior.;Chapter 3 describes the rationale behind moving from an ammonium headgroup to a phosphonium headgroup and the synthesis of a series of non-polymerizable amphiphiles that demonstrate the LLC forming ability of the trimethylphosphonium group, and the presence of HI and QII phases.;In Chapter 4, a polymerizable version of the alkyltrimethylphosphonium amphiphile incorporating a nonpolar 1,3-diene moiety as the polymerizable group is described. Additionally, the phase behavior and in-phase homopolymerization and copolymerization with divinylbenzene in the HI and QII phases is discussed.;Finally, in Chapter 5 a cross-linkable, phosphonium-diene, gemini amphiphile is described that adopts the desired phases and can be polymerized in those phases with retention of the phase architecture. |
