【作者】 廖梦圆； 卢枳岑； 陈晨； 谢海峰；

【机构】 南京医科大学附属口腔医院修复科； 南京医科大学附属口腔医院牙体牙髓科； 江苏省口腔疾病研究重点实验室； 江苏省口腔转化医学工程研究中心；

【摘要】 目的:常见的钛酸酯偶联剂中因缺少不饱和双键而无法与BisGMA/TEGDMA复合树脂形成加聚。设计一种新的钛酸酯分子,并通过热力学计算评估其与氧化锆的相互作用。方法:通过在钛酸酯分子的碳链末端添加不饱和双键构成一种新的钛酸酯分子。对新的钛酸酯分子及其与Zr408晶体的反应进行几何模型构建,并进行优化。采用密度泛函理论中的B3LYP算法(Becke’s3 parameters and the Lee-Yang-Parr’s nonlocal correlation functional)。对于碳、氢、氧原子,采用6-311+G(d,p)基组进行模拟。采用LanL2DZ基组来描述锆原子的价层电子和内层电子以及相关的相对论赝势效应。溶剂效应采用积分方程极化连续介质模型。以上所有计算均通过Gaussian 09软件(Gaussian公司,美国)完成。结果:热力学分析表明,新的钛酸酯分子与Zr408晶体簇在水溶液、乙醇溶液和丙酮溶液中发生配位结合反应的总吉布斯自由能分别为-96.95kJ/mol,-124.62kJ/mol,-152.99kJ/mol,表明新的钛酸酯偶联剂与Zr408晶体簇的反应在以上三种溶液中均能正向自发进行。结论:新的钛酸酯分子水解后能够与氧化锆形成化学结合,从而使氧化锆分散性增强、团聚程度减少。更多还原

【Abstract】 Objectives:Common titanate coupling agents cannot form addition polymerization with Bis-GMA/TEGDMA composite resin due to the lack of double bonds.In this study,a new titanate molecule was designed and its interaction with zirconia was evaluated through thermodynamic calculations.Methods:A new titanate molecule was formed by adding a double bond to the end of a carbon chain in the titanate molecule.Models of the new titanate molecule and Zr₄ O₈ cluster were constructed and then geometry-optimized.The density functional theory（DFT） along with the hybrid exchange functional of Becke’s 3 parameters（B3） and the Lee-YangParr’s nonlocal correlation functional（LYP） were used.The basis sets for carbon（C）,O,and H were 6-3 11+G^**.For Zr atoms,the valence and core electrons were described by the basis set of LanL2 DZ and the corresponding relativistic effective core potential（ECP）.The solvent effect was considered in the integral equation formalism polarizable continuum model（IEF-PCM）.All calculations were undertaken using Gaussian 09 software.Results:The thermodynamic analysis showed that the total Gibbs free energy of the new titanate molecule and the Z_r4 O₈ cluster in the water,ethanol and acetone solution for the coordination reactions were-96.95 kJ/mol,-124.62 kJ/mol,and-152.99 kJ/mol which indicating that the reaction between the new titanate coupling agent and Zr₄ O₈ cluster can proceed spontaneously.Conclusion:The new titanate molecule can form a chemical bond with zirconia after hydrolysis,thereby enhancing the dispersibility of zirconia and reducing the degree of agglomeration.更多还原