Effect of Microgravity on the Formation of Honeycomb-patterned Films by Dissipative Processes

Abstract

Honeycomb-patterned porous polymer films can be prepared by casting a mixed solution of hydrophobic and amphiphilic polymers on a solid substrate utilizing the condensed water droplet arrays as templates. Due to the temperature non-uniformity of the solution surface resulting from the thermal convections, water condenses heterogeneously. The heterogeneous condensation of water droplets induces the formation of irregular-arrangement of domains in the ordered structure of microporous films. In order to evaluate the effect of gravity on the formation of honeycomb-patterned films, we have made microgravity experiments. Even under microgravity, we successfully prepared honeycomb-patterned films. And interestingly, some samples have multi-layered uniform microporous structures, which are formed with vanishing the relative density effect of solvent and water droplets. It is suggested that the microgravity affects the formation of honeycomb-patterned films considerably.