| Using a combination of experiments and theory, this thesis outlines a fundamental study in liquid crystal phase transitions, and for the first time demonstrates a robust and easily scalable pathway for the self-assembly of nanostructured materials such as monolayer membranes or thin films and ribbon networks from homogenous rod-like molecules. As building blocks for liquid crystalline materials and self-assembled structures, we use a highly versatile system based on filamentous bacteriophages the fd virus. Through molecular cloning techniques, we demonstrate a single point mutation in the virus coat protein changes both the flexibility and chirality of the viruses, and use this as a means to provide a first quantitative test of the original Onsager theory for the liquid crystalline isotropic-nematic phase transition of rigid rods. Then, through the addition of non-adsorbing polymer, we demonstrate and outline conditions under which attractive interactions lead to the self-assembly of colloidal monolayer membranes. Despite a very different structure on molecular lengthscales, we demonstrate that the properties of colloidal membranes are identical to that of amphiphilic membranes or lipid bilayers, and offer experimental evidence that the Helfrich hamiltonian applies to monolayer membranes. We then investigate the influence of chirality on these colloidal membranes, offering experimental confirmation of an analogy proposed by deGennes that chirality is expelled from any 2D system in a manner analogous to the expulsion of a magnetic field from a superconductor. By tuning the strength of chiral interactions between constituent molecules, we demonstrate that chiral expulsion can be used to tune the membrane line tension or edge energy. In this regard, chirality plays an analogous role to surfactants, and similar to surfactant based control of interfacial tension, drives the self-assembly of numerous polymorphic assemblages such as linear and circular twisted ribbons, starfish membranes, and double and triple helices. |
