Silylated calcium phosphates and their new behavior for copper retention from aqueous solution

Anhydrous calcium phosphate (CaP) was modified by surface silylation using three organosilanes (H3CO)3SiR, where R corresponds to the organic moieties CH2CH2CH2NH2, CH2CH2CH2NHCH2CH2NH2 and CH2CH2CH2NHCH2CH2NHCH2CH2NH2, originating nanomaterials named CaPSil1, CaPSil2, and CaPSil3. The products were characterized by elemental analysis, infrared spectroscopy, X-ray diffraction, thermogravimetry and 31P and 13C NMR. The amounts of attached amino groups on surfaces were 0.32 ± 0.05, 0.54 ± 0.04, and 1.21 ± 0.04 mmol g−1 for CaPSilx (x = 1–3), respectively. Suspended silanized phosphates adsorbed copper cations from aqueous solution at liquid/solid interface.