摘要 |
Provided is a method of producing porous silica-based particles with the relatively larger average diameter of 1 micron or more and also having a low particle density. The method comprises the steps of (a) preparing two-layer separated liquid consisting of an organic silicon compound layer and a water layer, then adding an organic solvent, an alkali, and a surfactant into the water layer while agitating at least the water layer so that the organic silicon compound layer and the water layer are not completely mixed with each other, further hydrolyzing and/or partial hydrolyzing the organic silicon compound in the mixed aqueous solution to prepare silica-based particle precursors, (b) adding sodium aluminate into the mixed aqueous solution containing the silica-based particle precursors and then preparing silica-based particles having pores, cavities or voids inside the particles, and (c) washing and drying the silica-based particles. Thus obtained particles are useful for various applications such as microcapsules, adsorbents, catalysts, low refractive film, low dielectric film and low reflectivity film.
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