磷酸钙骨水泥中水化过程研究检测方案(差示扫描量热)

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ANS26Ceramics Hydration process of calcium phosphate cement Reference： Thermokinetic analysis of the hydration process of calcium phosphate cement.W.Y.Gao， Y.W. Wang， L.M. Dong and Z.W. Yu， Journal of Thermal Analysis and Calorimetry，Vol. 85 (2006) 3，785-789 Introduction： Calcium phosphate cements (CPC) have good biocompatibility because they areprepared with similar element composition and pore size to natural bone. So， they are usedclinically in bone repair for filling non-load bearing bone defects. For example， hydroxyapatite(HA) Ca10(PO4)6(OH)2， tricalcium rphosphate (TCP) Caq(PO4)2and dicalcium phosphatedihydrate (DCPD) CaHPO4，2H，0 were used for clinical applications. Fig. 1 ： The thermogenesis curves from mixingdifferent amounts of CPC and 2mL buffer at 37℃. Fig.2： The linear relationship between the totalheat of hydration process and the mass of CPC. Experimentah Results a-TCP was prepared from DCPD by reactingit with calcium carbonate. CPC was a mixtureof a-TCP and DCPD (molar ratio1：1)prepared by grinding them inanhydrousethanol， and subsequent drying and sifting1(the grain size approximately2pm).Thebuffer was citric acid buffer (pH=6.0). The integration of the thermogenetic curve(Fig.1) indicates the total heat generatedduring hydration of the CPC samples. A linearrelationship between the total heat ofhydration process and the mass of CPC canbe noted (Fig.2)..Theenthalpy wasdetermined to be 35.8 J g-1 at 37.0℃. A C80 microcalorimeter with inversing mixingcellswas used inthisSpublication. Thesamples studied were generated by mixingvarious amounts of CPC (5， 10， 20， 30， 50，60 and 80 mg) and 2.0 mL buffer and allanalysis were done at 37.0℃. Indeed， byreversing the calorimeter body containing theCPC preparation in the inner cell and buffer inthe outer cell， a thermogenetic curve of solid-liquidmixing procesS could thus begenerated. The mix must be performed at isothermaltemperature but the reaction is exothermic.So it is necessary to control the ratio CPC tobuffer solution. Indeed， with a ratio less than1：20， the heat evolved raise the temperatureless than 0.5℃ whereas， with a ratio near 1：2or 1：1， the temperature increase could be upto 4 or 5℃. We can also observe that the hydrationprocess of the CPC is quite fast and all thecurves return to baseline within half an hour. The reference cell contained 2.0 mL buffer. www.setaram.com- sales @setaram.com