Phase Behavior of alpha/omega-dihexyl-alpha-quaterthiophene and Ordering on a Textured Substrate
24 February 2003
Ordering of alpha,omega-dihexyl-alpha-quaterthiophene (DHalpha4T) on substrates including friction-transferred PTFE is explored. DHalpha4T exhibits a high-temperature mesophase from 81C to 181C. Textural analysis reveals this phase to be a tilted, highly ordered smectic phase. Upon cooling from the isotropic melt, the smectic phase grows layer by layer on many surfaces. Smectic thin films grown on friction-transferred PTFE exhibit a high degree of alignment. Upon crystallization from the mesophase, the material retains for the most part the order of the mesophase. Growth of the smectic phase on directional surfaces such as friction-transferred PTFE appears to be a route to control of surface ordering of DHalpha 4T.