Fabrication of transparent superhydrophobic polydimethylsiloxane elastomer by controlling the degree of combustion using thermal convection

Abstract

We report a quick and simple method to fabricate transparent superhydrophobic polydimethylsiloxane (PDMS) using partial combustion of PDMS by thermal convection. The fabrication process only uses PDMS as an ingredient and does not require harmful, expensive materials such as organic solvent or fluoropolymer. To make PDMS superhydrophobic, combustion reaction was used to create hierarchical structures with micro- to nano-scale roughness with low surface energy required for the fabrication of superhydrophobic surface. Combustion of PDMS surface created hydrophobic silica-containing nanoparticles. These nanoparticles are deposited on the PDMS surface, creating hierarchical nano-structures required for superhydrophobic surface. To minimize the damage from excessive heat and flame, thermal convection was used to control the degree of combustion during the fabrication process. The fabricated superhydrophobic surface showed static water contact angle of 155.6 degrees, and contact angle hysteresis of 5 degrees. The fabricated surface also maintained light transmittance greater than 70% of the maximum transmittance of pristine PDMS in visible light region.