Search academic texts

Information × Registration Number 0206U009265, 0105U005213 , R & D reports Title The spectroscopy study of nanodimension systems in biogenic and synthetic apatites popup.stage_title Head Lytovchenko Anatoly Stepanovich, Registration Date 27-12-2006 Organization nstitute of Geochemistry, Mineralogy and Ore Formation popup.description2 The research objects - biominerals and their synthetic analogues. The work purpose - the study of carbonate and OH-containing paramagnetic centers in apatites of various compositions. The research methods - EPR, NMR MAS, IR-spectroscopy, computer simulation. The СО2 molecules in water-organic matrix in OH-group places and the carboxylic aminoacid groups associated with nanocrystals are СО2- radical pre-centers. The paramagnetic ОН-O-НО centers have been appeared in synthetic isomorphically substituted Ca-HAP and bioapatites, presumably, when the О-Н-bond directions in the ОН-O-НО center changes. Isomorphous substitutions in hexagonal apatite influence on shieldings of 31P, 19F, 1H (NMR MAS). The 31P electron density rises in Cl-Ap, OH-Ap, F-Ap as a result of Sr > Ca and it decreases as a result of F > ОН, Cl. The strontium-90 sorption and desorption depended on a Сa-HAP crystal degree. It is proposed to sorb on poor-ordered apatite with its further transformation into well-ordered crystalline state. Product Description popup.authors popup.nrat_date 2020-04-02 Close