Papers by Author: Zhi Xian Zhang

Abstract: Alginate/silica composite beads of mm-size for biomedical applications were prepared from water glass and sodium alginate via a simple sol-gel route. They kept their original shapes when soaked in the phosphate solution of lower pH. In this case, faint calcium phosphate peaks were observed in X-ray diffraction. Peaks corresponding to phosphate group were also found in FT-IR. Apatite was obtained on the surface of beads made with calcium chloride after soaking in phosphate solution while monetite was formed on the surface of beads made with calcium nitrate.

Abstract: Using TiO₂ particles obtained by hydrolysis of titanium oxysulfate as the precursor, polystyrene (PS) microspheres as the template, TiO₂/PS complex particles were successfully deposited on Ti substrates through layer-by-layer self-assembly technique and the surfactant-assisted process at low temperature. Then removed PS spheres by two methods, TiO₂ hollow spheres were attained. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the synthesized materials. The results showed that the crystallization, structure and surface morphology of TiO₂/PS on the surface have a great relationship with the pH value of treating solution. Diversity effects on surface integrity and bioactive of hollow spheres happened due to different ways of removing PS core.