Reactive Crystallization Behaviour of Calcium Phosphate with and Without Whey Protein Addition
Reactive Crystallization Behaviour of Calcium Phosphate with and Without Whey Protein Addition
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添加和不添加乳清蛋白的磷酸钙的反应结晶行为
DOI：
10.1205/026387602753393277
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
T. Kuraishi
中科院分区：
文献类型：
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作者：
H. Tsuge;Y. Tanaka;S. Yoshizawa;T. Kuraishi
以磷酸钾和硝酸钙水溶液为原料，研究了磷酸钙的反应结晶过程。当反应开始时溶液具有高过饱和度时，无定形磷酸三钙（ACP），Ca 3（PO 4）2·nH 20作为初始固相立即沉淀。ACP的形成依赖于ACP的离子活度积，而与初始pH无关。ACP转化为磷酸钙，如磷酸氢二钙二水合物（DCPD），CaHPO 4·2 H2O，羟基磷灰石（HAP），Ca 5 OH（PO 4）3和磷酸八钙（OCP），Ca 8H 2（PO 4）6·5 H2O。研究了溶液pH值、反应温度和乳清蛋白添加量对磷酸钙反应结晶行为的影响。获得了磷酸钙的沉淀图，其为反应温度和初始溶液pH值的函数，其范围为15-50°C和5-9。乳清分离蛋白的加入抑制了磷酸钙的成核和生长。蛋白质的存在减缓了钙离子和磷酸根离子的反应。WPI的加入对DCPD和HAP的形态有一定的影响。DCPD变厚，聚集成束，表面不均匀，有裂纹。HAP颗粒的表面状态没有改变，但尺寸略有变化。通过添加WPI也观察到HAP的立方体形式，其可以通过自然干燥后的压碎形成，因为通过添加WPI获得的HAP非常硬地结块。
The reactive crystallization of calcium phosphate was studied by reacting potassium phosphate and calcium nitrate aqueous solutions in the batch system. When the solution has high supersaturation at the beginning of reaction, amorphous tricalcium phosphate (ACP), Ca3(PO4)2·nH20 was precipitated instantly as the initial solid phase. The formation of ACP depends on the ion activity product of ACP regardless of initial pH. ACP transforms to calcium phosphates such as dicalcium phosphate dihydrate (DCPD), CaHPO4·2H2O, hydroxyapatite (HAP), Ca5OH(PO4)3 and octacalcium phosphate (OCP), Ca8H2(PO4)6·5H2O. Effects of solution pH, reaction temperature and addition of whey protein on the behaviour of reactive crystallization of calcium phosphates have been studied. The precipitation diagram of calcium phosphates was obtained as a function of reaction temperature and initial solution pH, whose ranges were 15–50°C and 5–9. By the addition of whey protein isolate, the nucleation and growth of calcium phosphate were retarded. The existence of proteins slows down the reaction of calcium ions and phosphate ions. By the addition of WPI, the shape modification of DCPD and HAP was observed. DCPD became thicker, gathered in bundles and its surface was uneven and cracked. The surface state of HAP particles does not change, whereas the size changes slightly. The cubic form of HAP was also observed by addition of WPI, which may be formed by the crush after natural drying because HAP obtained was caked very hard by the addition of WPI.