Polydiacetylene Films Prepared in Microgravity

A diffusive/kinetic rate equation was developed for the growth of polydiacetylene films from solution and compared with a microgravity experiment. The model takes into account both the kinetics of thin film growth and the diffusive transport limitations inherent to microgravity. In order to apply this model, measurements of the density and the ultraviolet extinction coefficient of the films, as well as of the diffusion coefficient of the monomer/solvent system, were made. The thin films grown in microgravity were predicted by the model to grow to a thickness of 0.148 micron, versus 0.150 micron for the ground control films. The flight films grew to 0.102 micron.