An ex situ study of the adsorption of calcium phosphate from solution onto TiO2(110) and Al2O3(0001).

Ex situ atomic force microscopy and x-ray photoelectron spectroscopy are employed to characterise the adsorption of calcium phosphate from an aqueous solution of CaCl 2 .H 2 O and KH 2 PO 4 onto rutile-TiO 2 (110) and α-Al 2 O 3 (0001). Prior to immersion, the substrates underwent wet chemical preparation to produce well-defined surfaces. Calcium phosphate adsorption is observed on both rutile-TiO 2 (110) and α-Al 2 O 3 (0001), with atomic force microscopy images indicating island-type growth. In contrast to other studies on less well-defined TiO 2 and Al 2 O 3 substrates, the induction period for calcium phosphate nucleation appears to be comparable on these two surfaces. [ABSTRACT FROM AUTHOR]