Electrophoretic deposition of mesoporous silica powder synthesized by spray-drying method

Abstract

Desiccant air conditioning and humidity control systems, which utilize the water adsorption/desorption by porous materials, have attracted much attention as an environment-friendly and energy-efficient air conditioning system. Micelle-templated mesoporous silicas (MPS), which have been extensively studied in recent years, are considered as the optimum adsorbent for adsorption/desorption-based air conditioning systems because of their excellent water adsorption property due to their highly ordered porous structure; i.e., a uniform nanopores with an ordered arrangement. We first reported the formation of a thick coating of MPS powder on stainless steel by an electrophoretic deposition (EPD) method and then demonstrated the preparation of the MPS coating on aluminum substrates, which has the advantages of lightweight properties and high thermal conductivity. In this study, we investigated the dispersion stability of an EPD bath, and the influence of the EPD condition on the deposition amount in detail. The EPD bath composed of spray-dried MPS powder and acetone was stable 3min after the suspension was prepared, and the deposition amount could be easily controlled by the EPD conditions by changing the MPS powder concentration, the applied dc voltage and the deposition time. The obtained MPS thick coating had the same porous structure and adsorption properties with respect to nitrogen and water vapor as the parent spray-dried MPS powder. © 2011 The Ceramic Society of Japan.