Investigation of Sm3+ ion substitution in the hydroxyapatite-chitosan nanocomposite

Hydroxyapatite (HA), the major component of hard tissue, has properties that include deodorization, protein adhesiveness, bioactivity, and biocompatibility [1]. An important and interesting property ofHA isits ability to undergoion-exchange but low mechanical strength and high packing density of hydroxyapatite lead to the limitation of its industrial application.As one of the methods to overcome these limitations, a recent study has attempted to utilize HA/chitosan nanocomposites [2].It is known that lanthanide ions have ability for substitution with the Ca2+ sites within HA, because of their similarities in ionic radii, donor atom requirements, and coordination geometries [3]. In this study hydroxyapatite-chitosan nanocomposite wasprepared and characterized by FTIR, SEM and BET analysisMoreover, itsion exchange properties and Sm3+ ion substitution in the were evaluated . Its ion exchange capacity (IEC) of prepared nanocomposite for Sm3+ was found to be 0.91meq.g−1. Distribution coefficients (Kd) values for Sm3+ ion was also determined. For this purpose batch experiments were carried out using synthetic hydroxyapatite-chitosan nanocomposite. Parameters that influence the substitution reaction such as contact time, temperature and pH of solution were investigated.The maximum sustitution was found at contact time of 8 h and 9 h, temperature of 25 ºC and pH of 7. The results indicated that the hydroxyapatite-chitosan nanocomposite used in this work proved to be effective material for substitution of Sm3+ ions in aqueous solutions.