Growth Of Hydroxyapatite On Sulfonated Polybenzimidazole Membranes

Organic polymer coated with hydroxyapatite(HA) is an attractive material for the development of tissue repairing application. The abilities of hydroxyapatite incubation on poly [2,2'-(p-oxydiplienylene)-5,5'-bibenzimidazole] (OPBI) and sulfonated poly [2,2'- (p-oxydiphenylene)-5,5'-bibenziniidazole] (SOPBI) membranes were Investigated with the combination of alternate soaking process and simulated body fluid (SBF) soaking methods. Hydroxyapatite phase was analyzed by SAED and ATR-MR method. Morphology changes of the hydroxyapatite were observed by SEM. The results show that the use of the SOPBI membranes leads to a higher hydroxyapatite formation rate than that of the OPBI membranes. The sulfonic groups of SOPBI membranes not only offer a negative charged surface to attract Ca2+ but also help imidazole groups to bind Ca2+. In comparison, OPBI membranes without sulfonic groups decrease formation ability of hydroxyapatite because protonation types of imidazole groups in alternate soaking solutions inhibit interaction between imidazole and Ca2+ and HpO(4)(2 -), which can not be improved by the subsequent SBF soaking.