Cellulose/TiO2 Hybrid Spherical Microbeads Prepared by a Viscose Phase Separation Method: Control of the Distribution of TiO2 Particles in a Sphering System

Cellulose/TiO2 hybrid spherical microbeads were prepared by a one-step phase separation method using a cellulose xanthate aqueous solution and a sodium polyacrylate aqueous solution. Various types of cellulose/ TiO2 hybrid spherical microbeads were obtained by using the several kinds of TiO2 particles. The resulting hybrid spherical microbeads showed respective differences in the distribution of TiO2 particles. EPMA observation of the surface of hybrid spherical microbead clearly showed where the TiO2 particles were distributed. In addition, the extent of coverage by TiO2 particles of the surface was also confirmed by external appearance, because the surface of cellulose/ TiO2 hybrid spherical microbeads on which there were relatively few TiO2 particles appeared dark yellow. In contrast, the cellulose/TiO2 hybrid spherical microbeads on which TiO2 particles aggregated densely appeared white. It was suggested that the distribution of TiO2 particles on the hybrid spherical microbeads was related to electric repulsion between the CSS group and TiO2. The narrower the zeta potential distribution of TiO2 particles in the sphering pH condition (i.e., in pH 13 aqueous solution) is, the more TiO2 particles were driven out from the cellulose xanthate domain. [DOI 10.1295/polymj.37.186]