Preparation of fine composite particles composed of inorganic solid powders and organic polymers by utilizing liquid–liquid dispersion

Microencapsulation of thermal-sensitive pigment with inorganic wall material by interfacial reaction in multiple dispersion

Sol-gel process of silicon alkoxide was performed in reverse suspension to limit the sites of hydrolysis and dehydration-condensation of alkoxide to the inside of the dispersed droplets and to prepare silica particles of tens μm in diameter. Acetic acid aqueous solution was used as a dispersed phase, and hexane as a continuous phase. The dispersed phase was poured into the continuous phase, in which silicon alkoxide has dissolved, with stirring to form a reverse suspension. Silica particles of 67 μm in mean diameter were obtained by calcining the gel particles produced. Effects of pH of the dispersed phase and concentration of dispersion stabiliser on the characteristics of the silica particles were discussed. The formation mechanism of the gel particle was inferred with applying Jander's model, which is often used to analyse solid phase reaction of particles.

Akira Souma

Papers

The preparation of microcapsules which include silicon carbide particles in a wall material