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Paul V. Braun
Professor of Materials Science and Engineering, University Scholar
Office 204A Materials Science and Engineering Building
Telephone 217-244-7293 Fax 217-333-2736
Mail Address Department of Materials Science and Engineering
1304 W. Green St., Urbana, IL 61801
Our research program covers a range of materials science disciplines, with a general focus on the formation and study of nano and microstructures through self and directed assembly. Materials containing structure on these length scales have been found to exhibit interesting and important electrical, optical, mechanical and biological properties. We often use and develop new materials chemistry approaches to the synthesis of these materials, which allows us to create novel structures and materials including photonic bandgap structures, conducting polymers, nanostructured ceramics, semiconductors, biomaterials and metals. An important nanostructured system we study is liquid crystals, which can be designed to contain periodic structure ranging from one nanometer to greater than 100 nanometers. We are exploring multiple methodologies to use the periodic structure of these and other self-organized matrices to create new materials.
The liquid crystal mediated synthesis of materials could provide many yet unseen properties. One group objective is to use liquid crystals to create chemically functionalized hollow nanospheres, which would serve as site-specific drug delivery agents. Another application for hollow nanospheres is to form low dielectric constant materials for high-speed microelectronics. Liquid crystal mediated synthesis of materials is a new field, and very few of the basic principles are known or understood. We are attempting to quantify the important parameters, such as the liquid crystal–product interaction, and the effect of the liquid crystal's structure. Along with hollow nanoobjects, we are also studying the liquid crystal templating of such materials as conducting polymers and metals.
Another component of our research is the formation and characterization of photonic bandgap structures. Structures exhibiting photonic bandgaps have very interesting and potentially important optical properties. For example, waveguides formed from photonic bandgap materials can execute a 90 degree turn over a few microns, which is necessary for the on-chip integration of optical devices. One way to form the periodic structure necessary to realize a photonic bandgap is through templating with self-organized colloidal crystals. We are developing new routes to the formation of such structures, as well as modeling and measuring their optical response.