纳米羟基磷灰石/聚乳酸金属薄膜界面微结构与模拟研究

Nano-hydroxyapatite (nHA) and its polymer composite coating is a hot research topic in the field of inorganic biomimetic materials, and has broad application prospects. However, the surface of the metal coating is easy to produce defects of crack, and doesn't show higher bond strength, which thus tends to reduce the use of its performance. This project employs molecular dynamics (MD), Monte Carlo (MC) and the numerical analysis method, combined with a series of modern analytical and testing means including XRD, PAT, DTA, FTIR, SEM, and SAXS, to study systematically the interfacial interactions, microstructures and defect properties of nano-hydroxyapatite/polylactic acid (PLA) coating on metal substrate. And it reveals the relationship between preparation, composition, morphology and properties of the coating surface and its interface molecular interaction and microscopic structure change. Through MD, MC and fractal theory the influence of HA/PLA composite defects on coating interface adhesion will be also studied. Meanwhile, the fractal model of the interface may be established so as to elucidate the rule of the fractal dimension, structure and properties of composite coating. As a result, the molecular simulation software system of the computer is built, and will attempt to provide scientific basis for the preparation of high performance composite coating with uniform surface, stable structure and good adhesion strength. This helps accelerate the industrial development of nano-hydroxyapatite composite coating and clinical application.

纳米羟基磷灰石（HA）及其高分子复合膜是当今无机仿生材料领域的热门研究课题，具有广泛的应用前景，然而其金属薄膜表面存在易产生裂纹、粘结强度不高等缺点，降低了它的使用性能。本项目采用分子动力学（MD）、Monte Carlo（MC）模拟以及数值分析方法，结合XRD、PAT、DTA、FTIR、SEM、SAXS等现代分析测试手段，从分子和原子水平系统研究纳米羟基磷灰石/聚乳酸（PLA）复合金属膜界面作用、微观结构和缺陷性质，揭示复合膜界面分子作用和微观结构变化与其制备、组成、表面形貌和性能之间的关系，通过MD、MC模拟和分形理论研究HA/PLA复合材料晶体缺陷对膜界面粘附力的影响，建立界面的分形模型，明确分形维数与复合膜结构性能的规律。建立HA/PLA复合金属膜的分子模拟计算机软件系统，为制备表面均匀、结构稳定、粘附强度好的高性能复合膜提供科学依据，加速纳米羟基磷灰石复合膜产业化发展和临床应用。

本项目通过湿化学法和旋涂法分别合成了羟基磷灰石（HA）晶体及HA/聚乳酸(PLA)复合金属膜, 对复合膜制备条件进行了优化研究,得到了粘结强度好、性能稳定可靠的HA/PLA复合膜。由于近年来多种人体微量元素(如锌、铈、银等)在HA中进行掺杂有着广泛的研究和应用，本项目在HA/PLA复合膜基础上增加了合成锌（或铈、银）掺杂HA/PLA复合膜及相关性能表征与研究，其中合成的银掺杂HA/PLA复合膜期待在生物医用领域有着良好的抗菌应用前景。在合成膜基础上，运用分子动力学（MD）和第一性原理计算对HA/PLA或缺陷HA/PLA及Zn掺杂HA/PLA复合膜界面微观结构、缺陷及性能进行了模拟研究,以进一步探究了HA/PLA复合金属膜的界面结构与性能特征，从而对HA及其HA/PLA复合膜实验研究起到重要的理论指导意义。