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Information × Registration Number 0218U001428, 0117U004871 , R & D reports Title Crystallization and characteristics of bone cements based on the metastable alpha-tricalciumphosphate. popup.stage_title Head Zyman Zoltan Zoltanovich, Registration Date 13-03-2018 Organization Kharkov National University named after V.N. Karazin popup.description2 Processes of ACP crystalization. Influence of impuritys and particular dispersion on characteristics and phase composition of ACP crystalization products. Conditions of formation and characteristics of metastable -TCP phase. The objects of research are nano-dispersed amorphous, nanocrystalline and submicrocrystalline samples of calcium phosphates (CP) with ratio of 1.0 <Ca / P <1.67. Subject of research - features of composition, structure, morphology, crystallization, structural transitions in CP with 1.0 <Ca / P <1.67 at 20 - 1000 ° С. The purpose is determination of regularities of formation of the initial composition and structure, crystallization of equilibrium and metastable phases, thermal phase transitions in CH with ratio 1.0 <Ca/P <1.67, as well as the conditions for obtaining perspective biomaterials on their base. It has been determined that amorphous calcium phosphate powders consist of inorganic particles having an inhomogeneous composition. The particle has a core with Ca/P = 1.5, covered by shell with close to bruchite composition (Ca/P = 1). Annealing of samples in the air at 670 ?C leads to certain there transformations. In the 25-280 °С range, dehydration leads to the transformation of surface layer shell into a monetite-like shell. Interaction of a shel layers with adjacent core regions at 280-470 °C temperature leads to the formation of OCP. In the 470-640 °C range OCP becomes a non-stoichiometric HA (probably due to interaction with the surrounding water vapor). Powder samples at about 670 °C crystallize in (?) -TCP, ?- TCP and ?-PCP. The heating of samples above 670 ?C led to the completion of crystallization at about 800 ?C and the gradual conversion of -TCP to ?- TCP. Product Description popup.authors А. Гончаренко А. Пройдакова В. Коршак Д. Рохмістров З. Зиман Л. Подус М. Ткаченко О. Онищенко О. Пяничук popup.nrat_date 2020-04-02 Close