Composite hydroxyapatite -Na/MCM-41 for the fluoride retention in contaminated water

A. Laghzizily et al. [1] correlated the fluorination of hydroxyapatite (HaP) results with its physicochemical properties. We introduce the idea of composite, in order to anchor nanocrystals of HaP (guest) in host of the MCM-41 materials developed by us [2]. The pore size of the materials used as support is 1-30 nm. We expect the formation of smaller nanocrystals of HaP than the cavities in the host. We also consider the possibility of growth of the clusters of HaP in the external surface. The composite was characterized by XRD, FTIR, BET and TEM. Fluoride retention capacity increased in one order of magnitude respect to pure HaP, due the formation of HaP nanocrystals in MCM-41 (M41).