Design and synthesis of dynamic materials

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Research in the Williams group focuses on developing the tools that will enable us to exert control over the structure of materials at the nano-, micro- and macroscale.   We are pursuing two primary avenues of enquiry: 1) the study of columnar liquid crystals, which exhibit the unusual property that they are simultaneously ordered and fluid; 2) the design of materials based on reversible photochemical reactions, which permits us to control the properties of materials using light.    Our studies of liquid crystals focus on a specific class of molecules known as discotic mesogens.  These disc-shaped molecules stack into fluid columnar structures.  Columnar liquid crystals have received considerable attention in recent years as candidates for applications such as photovoltaics (i.e. solar cells), LEDS and chemical sensors.  We are trying to understand how changes at the molecular level impact upon the self-organization of molecules into liquid crystalline phases.  Such an understanding is essential if we are to design materials that can be commercialized, and is also crucial to the fundamental understanding of self-assembly processes.   We are also examing the use of anthracene derivatives in the design of new materials.  These molecules exhibit the notable feature that, when irradiated with near-UV or visible light, they form robust dimers.  These dimers can be converted back into the original anthracene molecules by exposing them to shorter wavelengths of light.  Hence, it is possible to put together and take apart materials using light of different wavelengths.  This gives us the opportunity to create materials who properties can be programmed "on-the-fly".  We are developing new methods in which to exploit this reactivity that will impact upon a broad range of disciplines, including catalysis, combinatorial chemistry, block copolymers, microfluidics and drug delivery.