Preparation of mesoporous silica with amphiphilic poly(oxyethylene)/ poly (oxybutylene) diblock and poly(oxyethylene)/poly(oxypropylene) triblock copolymers as templates

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Mesoporous silica can be formed with amphiphilic molecules acting as structure-directing templates in dilute systems. The effect of different block lengths of Pluronic surfactants, (EO)_x-(PO)_y-(EO)_x, has been investigated and compared with that of poly(oxyethylene)/poly(oxybutylene) diblock copolymer in the formation of the mesoporous silica. Comparison is also made with earlier reports [Kipkemboi <i>et al.</i>, <i>Langmuir</i>, 17 (2001) 5398] on the formation of the mesoporous materials. Micellar solutions of copolymers have been utilized for templated-silica synthesis under acidic conditions. Calcination of the silica products gives mesoporous materials. The EO-block length of the polymers determines the mesostructure of the silica. The synthesis temperature also influences particle size, wall thickness and pore diameter. The materials have been characterized by SAXS, transmission electron microscopy and nitrogen adsorption measurements. </smarttagtype>