Morphological and Structural Investigation of Octacalcium Phosphate Hydrolysis in the Presence of Polyacrylic Acids: Effect of Relative Molecular Weights
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- 作者：Adriana Bigi ; Elisa Boanini ; Gianna Cojazzi ; Giuseppe Falini ; and Sivia Panzavolta
- 刊名：Crystal Growth & Design
- 出版年：2001
- 出版时间：May 2001
- 年：2001
- 卷：1
- 期：3
- 页码：239 - 244
- 全文大小：314K
- 年卷期：v.1,no.3(May 2001)
- ISSN：1528-7505
文摘
The results of this paper indicate that poly(acrylic acid)s of different molecular weights (PAA2, Mw= 2000; PAA250, Mw = 250 000) inhibit the hydrolysis of octacalcium phosphate (OCP) into hydroxyapatite (HA) toan extent that depends on their concentration in solution, as well as on their molecular weights. This inhibition,which takes place through poly(acrylic acid) adsorption on OCP crystals, is more effective for PAA2 than for PAA250.The significant increase of the roughness of the OCP crystal surface after adsorption of PAA250, put into evidenceby AFM images, and the decrease of the coherence lengths of the perfect crystalline domains along the c-axis directionof OCP crystals after adsorption of PAA2 suggest that the shorter length of PAA2 molecules allows a greater andmore ordered interaction with the hydrated layers of the (100) face of OCP. The results of TEM investigation suggestthat OCP hydrolysis occurs according to a layer-to-layer mechanism that implies splitting into smaller crystals andaccounts for the platelet-like morphology of the final apatitic crystals.