Yuhui Li

Ph.D. candidate in Pharmaceutical Sciences, UW-Madison

B.S. in Chemistry, University of Science and Technology of China (USTC), China, 2017

Surface mobility plays a central role in the stability of amorphous materials, enabling fast crystal growth on surfaces and formation of high stability glasses by vapor deposition. Previous work has shown that diffusion can be much faster on the surface of molecular glasses than in the bulk and that the rate of surface diffusion at the glass transition temperature Tg is a function of molecular size modified by the extent of hydrogen bonding. This work has focused on systems containing quasi-spherical molecules, isotropic molecular glasses, and dry conditions. What I am doing is to evaluate the effects of other important factors on surface diffusion, including molecular shape, bulk liquid-crystalline structure, and ambient moisture. Furthermore, by knowing the vulnerability of the surfaces, methods, like surface coating, has been developed to extend the shelf life of amorphous formulations.