The effects of interfacial tensions of amphiphilic copolymers on honeycomb-patterned films

A honeycomb-patterned film is formed by casting a polymer solution of polystyrene and amphiphilic copolymer under humid condition. Amphiphilic copolymers stabilize condensed water droplets as temporal templates. Therefore, physical properties of the amphiphilic copolymer are important factors for stability of condensed water droplets and the structure of the honeycomb-patterned film. In order to verify the effect of the interfacial tension between water and chloroform solution of the amphiphilic copolymer, which is one of the important physical properties, amphiphilic copolymers were synthesized from hydrophobic monomer and hydrophilic monomer at various copolymerization ratios. The interfacial tension decreased with increasing the copolymerization ratio of the hydrophilic comonomer. Uniformity of micropores of the honeycomb-patterned film increased with decreasing the value of the interfacial tension. Moreover, polymer frame of honeycomb-patterned film became thinner with decreasing the value of the interfacial tension. These results indicate that the structure of honeycombpatterned film can be controlled by the interfacial tension between water and polymer solution.