The surface of colloidal strontium hydroxyapatite (SrHAP) particles with different Sr : P molar ratios from 1.51 to 1.71 has been characterized by means of an FTNIR spectrometer. The IR spectra of the Sr-deficient SrHAP gave rise to 3684, 3662 and 3640 cm–1 bands, which are assigned to surface P—OH groups. The Sr-rich SrHAP exhibited a band at 3710 cm–1 in addition to the three surface P—OH bands. The amount of irreversible adsorption of CO2 on the Sr-rich SrHAP was larger than that on the Sr-deficient samples. The change in the spectra after CO2 adsorption by the sample proved that the irreversible adsorption sites of CO2 on the Sr-deficient SrHAP are the less-acidic surface P—OH groups giving the 3640 cm–1 band and those on the Sr-rich SrHAP are surface OH– ions. The mechanism of irreversible adsorption of CO2 is discussed.
No takes yet. Share an insight, caveat, or question.
Ishikawa et al. (1992) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: