Novel Porous Materials Prepared by Repeated Directional Crystallization of Solvent

Herein, novel porous structures were fabricated from monomer solutions of dimethylsiloxane and benzene by directional crystallization in twice. First, a honeycomb-like structure was fabricated by 1st directional crystallization of solvent. By infiltration of the solution and subsequent 2nd directional crystallization, novel structures of different pores in the honeycomb-like structure were fabricated. The porous materials prepared by the repeated directional crystallization have higher indentation modulus and hardness than those of the samples prepared by single directional crystallization. When a higher solution concentration was used in 2nd directional crystallization, the maximum increase (indentation modulus: 2140% increase, indentation hardness: 2330% increase) was obtained. On the other hand, porosity and contact angle were lower in the samples from 2nd directional crystallization than those from 1st directional crystallization. A large decreases was observed, when a relatively high concentration was used in 2nd directional crystallization (porosity: 21% decrease, contact angle: 36% decrease).