Effect of preparation conditions on the properties of microspheres prepared using an emulsion-solvent extraction process

• Published in: Chemical engineering research & design 2012-10, Vol.90 (10), p.1517-1526
• Main Authors: Heiskanen, Harri, Denifl, Peter, Pitkänen, Päivi, Hurme, Markku
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical engineering; Chemical engineers; Chemistry; Colloidal state and disperse state; Dispersion; Emulsification; Exact sciences and technology; General and physical chemistry; Liquid-liquid extraction; Microsphere; Microspheres; Particle size distribution; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Solidification; Solvent extraction; Stirring; Surfactants
• ISSN: 0263-8762
• DOI: 10.1016/j.cherd.2012.02.008

► A hydrocarbon-in-perfluorocarbon emulsion was used. ► Size of microspheres decreased with increasing stirring speed. ► Size of microspheres decreased with decreasing surfactant concentration. ► Size of microspheres was affected also by volume ratio of emulsion phases. ► A slow solidification increased the formation of non-spherical microspheres. Methylaluminoxane microspheres were prepared using a hydrocarbon-in-perfluorocarbon-emulsion solvent extraction process. The effect of the preparation conditions on the size of the microspheres was investigated. As expected, the size of the microspheres decreased with increasing stirring speed. At low surfactant concentrations the size of the microspheres was independent of the surfactant concentration. However, the size of the microspheres decreased as the surfactant concentration was further increased. The size of the microspheres was not only affected by the surfactant concentration but also by the volume ratio of the dispersed phase to the continuous phase. At a low volume ratio of the phases the effect of the surfactant on the size of the microspheres was larger than the effect of the increased volume ratio of the phases. At high volume ratios of the phases the effect of the volume ratio of phases on the size of the microspheres became more significant than the effect of the surfactant. A slow solidification increased the formation of non-spherical microspheres.