August 2001 Ž . Materials Letters 50 2001 87–91 www.elsevier.comrlocatermatlet Preparation of mesoporous material having a hydrophobic surface by combining silica xerogel with resin using sol–gel method Jun’ichi Hayashi a,b, ) , Yuuki Watada b , Katsuhiko Muroyama b a High Technology Research Center, Kansai UniÕersity, 3-3-35, Yamate-cho, Suita, Osaka 564-8680, Japan b Department of Chemical Engineering, Faculty of Engineering, Kansai UniÕersity, 3-3-35, Yamate-cho, Suita, Osaka 564-8680, Japan Received 19 October 2000; accepted 24 November 2000 Abstract We tried to prepare a mesoporous material with a hydrophobic surface by combining the silica xerogel with the phenol–formaldehyde resin using the sol–gel method. During the procedure, the formation of the silica xerogel and the formation of phenol–formaldehyde resin simultaneously occurred in the liquid phase. Then, the pore structure of the xerogel was different from the simple mixture of silica xerogel and phenol–formaldehyde resin. It is found that the pore size can be tailored by changing the phenol–formaldehyde resin ratio. q 2001 Elsevier Science B.V. All rights reserved. PACS: 81.20 yn; 61.43 Gt; 61.43 Er Keywords: Inorganic–organic hybrid material; Sol–gel; Xerogel; Adsorption; Pore structure; Hydrophobic surface 1. Introduction Porous materials are widely used as adsorbents or catalyst supports in various fields. The performance of a porous material mainly depends on its pore structure and surface characteristics. Therefore, it is very important to control the pore structure and the surface characteristics of the porous material. How- ever, it has been often difficult to prepare porous materials with the desired properties for utilization in the current industrial field from one starting material alone by a conventional method. Therefore, combi- ) Corresponding author. Department of Chemical Engineering, Faculty of Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan. Tel.: q 81-6-6368-0913; fax: q 81- 6-6388-8869. Ž . E-mail address: hayashi7@ipcku.kansai-u.ac.jp J. Hayashi . nations of different types of materials to create new composite material with desired properties have been tried. We tried to prepare a mesoporous material with a hydrophobic surface, which is effective for the ad- sorption of the large molecules in aqueous solution. The silica xerogel is known as a mesoporous mate- rial with a hydrophilic surface due to the presence of Ž . a silanol group. Phenol–formaldehyde resin PF char is not a mesoporous material, but its surface is hydrophobic. By combining the silica xerogel with PF char, we aimed at preparing a mesoporous mate- rial with a hydrophobic surface. The sol–gel method is a very useful method to prepare composite materials. In the sol–gel process, the hydrolysis and condensation of metal alkoxides occur to form an inorganic metal oxide. Therefore, it is expected that the nanocomposite material can be 00167-577Xr01r$ - see front matter q 2001 Elsevier Science B.V. All rights reserved. Ž . PII: S0167-577X 00 00421-3