Nanotechnology - New advanced hybrid polymeric nanomaterials

Understanding and controlling the hydrolysis and condensation of trialkoxy and tetraalkoxy silanes in acidic medium has not been fully realised. Sanchez et al [1] found that with certain compositions, the reaction quickly reaches a pseudo equilibrium. Hence, the condensation rate coefficient could be determined [2]. One aspect of our work has been to study these reactions to pseudo equilibrium and beyond to understand what happens when excess reagents are being added after equilibrium. This study gave us an understanding of the durability or shelf-life of the materials formed. We also examined how varying the amounts of reactants affected the composition of the pseudo equilibrium. Another aspect of the research was to study silsesquioxane condensation in order to understand and control the mechanism to obtain different desired advanced materials [3]. We have also been able to extend our understanding from the above mechanistic study to the synthesis of Stober silica nanoparticles of variable sizes [4]. References [1] J. Sanchez, S. E. Rankin, A. V. McCormick, Industrial & Engineering Chemistry Research 1996, 35, 117-129. [2] F. Bauer, V. Sauerland, H. Ernst, H.-J. Glsel, S. Naumov, R. Mehnert, Macromolecular Chemistry and Physics 2003, 204, 375-383. [3] A. R. Bassindale, H. Chen, Z. Liu, I. A. MacKinnon, D. J. Parker, P. G. Taylor, Y. Yang, M. E. Light, P. N. Horton, M. B. Hursthouse, Journal of Organometallic Chemistry 2004, 689, 3287-3300. [4] W. Stber, A. Fink, E. Bohn, Journal of Colloid and Interface Science 1968, 26, 62-69.