title: Transformation of amorphous calcium carbonate to rod-like single crystal calcite via "copying" collagen template.
abstract: Collagen Langmuir films were prepared by spreading the solution of collagen over deionized water, CaCl2 solution and Ca(HCO3)2 solution. Resultant collagen Langmuir monolayers were then compressed to a lateral pressure of 10 mN/m and held there for different duration, allowing the crystallization of CaCO3. The effect of crystallization time on the phase composition and microstructure of CaCO3 was investigated. It was found that amorphous calcium carbonate (ACC) was obtained at a crystallization time of 6 h. The amorphous CaCO3 was transformed to rod-like single crystal calcite crystals at an extended crystallization time of 12 h and 24 h, via "copying" the symmetry and dimensionalities of collagen fibers. Resultant calcite crystallites were well oriented along the longitudinal axis of collagen fibers. The ordered surface structure of collagen fibers and electrostatic interactions played key roles in tuning the oriented nucleation and growth of the calcite crystallites. The mineralized collagen possessing both desired mechanical properties of collagen fiber and good biocompatibility of calcium carbonate may be assembled into an ideal biomaterial for bone implants.
authors.affiliation: Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, PR China; School of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000, PR China.
authors.forename: Zhonghui
authors.initials: Z
authors.lastname: Xue
authors.affiliation: Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, PR China.
authors.forename: Binbin
authors.initials: B
authors.lastname: Hu
authors.affiliation: Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, PR China.
authors.forename: Shuxi
authors.initials: S
authors.lastname: Dai
authors.affiliation: Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, PR China. Electronic address: zld@henu.edu.cn.
authors.forename: Zuliang
authors.initials: Z
authors.lastname: Du
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission
chemical_list: D003094:Collagen; D002119:Calcium Carbonate
keywords: Crystal growth; Crystal structure; Interfaces; Nanostructures