State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University, Shanghai, 200433, P.R. China.
Macromol Biosci. 2013 May;13(5):650-9. doi: 10.1002/mabi.201200334. Epub 2013 Apr 22.
A well-defined amphiphilic polypeptide, poly(glutamic acid)22 -block-poly(alanine)8 (PGlu22 -b-PAla8 ), which plays the roles of both soluble (functional) additive and insoluble (structural) matrix, is employed to mediate the mineralization of CaCO3 at the air/water interface. X-ray diffraction (XRD) and Raman spectroscopy, for example, show that the polymorph of CaCO3 particles obtained is calcite. The observations from SEM and TEM suggest that PGlu22 -b-PAla8 initiates the amorphous precursor phase and heterogeneous nucleation of CaCO3 at the air/water interface, while temporarily stabilizes the gelatinous precursors as a process-directing agent; nevertheless, the initial concentration of Ca(2+) controls the procedure of crystallization and the final morphology of CaCO3 particles. Such "bifunctional" amphiphilic-polypeptide-regulated mineralization at the air/water interface may be applied to the synthesis of many kinds of symmetrical inorganic/organic hybrids.
一种具有明确两亲性的多肽，聚（谷氨酸）22 - 嵌段 - 聚（丙氨酸）8（PGlu22 -b-PAla8），既可以作为可溶性（功能）添加剂，也可以作为不溶性（结构）基质，用于介导碳酸钙在气/水界面的矿化。例如，X 射线衍射（XRD）和拉曼光谱表明，所得到的碳酸钙颗粒的多晶型物为方解石。SEM 和 TEM 的观察结果表明，PGlu22 -b-PAla8 在气/水界面引发了碳酸钙的无定形前体相和异质成核，同时作为过程导向剂暂时稳定了凝胶状前体；然而，初始 Ca(2+)浓度控制着结晶过程和碳酸钙颗粒的最终形态。这种“双功能”两亲多肽在气/水界面的矿化作用可能适用于多种对称无机/有机杂化材料的合成。
