埃洛石纳米管负载掺杂氧化锌制备复合抗菌材料的基础研究

Preparation of advanced materials based on the characteristics of natural minerals is becoming a frontier field of interdisciplinarity. This project aims to construct high-performance antibacterial composites by loading Ce-doped ZnO nanoparticles on the surface of halloysite nanotubes (HNTs) and perform the property control of the composites by optimizing process and adjusting component. Coupling mechanism of various paramenters in the solid-liquid complex system is analyzed, and effects of loading and doping on the structure and morphology of the composites are investigaed. Possible synergetic effect between HNTs structure and better antibacterial activity of Ce-ZnO nanoparticles is discussed. We also try to ascertain the impact of interphase feature and size effect of nano Ce-ZnO and HNTs on the antibacterial activity of Ce-ZnO/HNTs composites. First-principles density functional theory (DFT) calculations is employed to build atomic structure model for the complex system, revealing the combination mechanism of the interface binding between functional nanoparticles and mineral substrate at the atomic and molecular levels. By combining the experimental results and the theoretical calculations, we try to establish the designing principles for stabilizing the interface structure of the composites as a whole. The project is also to investigate the natures of functionalized HNTs enhancing the structure and performance of antibacterial products according to the characteristics of applied polymer, which provides practical application with reliable fundamentals. The accomplishment of the project could offer new idea for the low-cost preparation of advanced antibacterial composites, and show important theoretical significance and application value for the high-valued utilization of mineral resources and the production of advanced functional mineral materials.

基于矿物天然特性构筑新材料是多学科交叉的前沿领域。本项目利用埃洛石的天然纳米管负载铈掺杂氧化锌纳米颗粒制备高性能复合抗菌材料，通过工艺优化及组份调节实现材料的性能调控。研究固-液复杂体系的多因素耦合机制，分析负载与掺杂对纳米管结构和形貌的影响，探讨埃洛石纳米管结构与铈掺杂氧化锌抗菌效能的协同效应，查明掺杂氧化锌/纳米管的界面特性和尺寸效应对复合材料抗菌性能的影响规律。引入第一性原理的密度泛函计算，建立复合体系的原子结构模型，从原子、分子层次揭示纳米颗粒与矿物的界面结合机制；结合实验与理论计算，构建复合材料界面结构稳定化的设计方法。并根据应用对象高聚物的特性，系统考察复合材料的功能化纳米管对抗菌制品结构/性能的强化规律，为实际应用提供可靠的依据。本项目的完成可为高性能抗菌材料的低成本制备提供崭新的思路，也对矿物资源的高值化利用和高性能功能矿物材料的制备具有重要的理的理论意义和应用价值。

利用埃洛石纳米管（HNTs）的天然结构特性，通过负载CeO2（或Ag）纳米颗粒掺杂复合纳米ZnO成功制备出高性能复合抗菌材料，并实现复合抗菌材料的性能调控。纳米颗粒较为密集的分布于细菌细胞间隙、细胞壁，同时紧密团聚在大肠杆菌细胞膜表面，部分纳米颗粒可渗透入细胞内部在细胞质发生作用。复合材料可产生更多的电子及空穴，从而与空气及水发生反应，产生较多的活性氧抑制细菌的增殖。HNTs较大的比表面积及管径结构，减弱了ZnO及纳米颗粒的团聚性，有助于提高抗菌性能。研究阐明了埃洛石的纳米管结构与掺杂纳米ZnO抗菌效能的协同效应，揭示了黏土矿物与功能颗粒的界面结合机制。进一步以插层改性高岭石为基体，通过控制反应体系的pH值可调节Fe2O3纳米颗粒在高岭石表面的分布密度，可以实现Fe2O3/高岭石复合材料的抗菌性能可控。Fe2O3颗粒与高岭石片层紧密结合，且复合材料能覆盖在大肠杆菌上，高岭石较强的吸附能力明显促进复合材料与大肠杆菌的结合，暴露的活性位点及羟基自由基可获得更好的抗菌性能。在Advanced Functional Materials、Chemical Communications、Applied Clay Science等国际期刊上发表学术论文11篇（其中NI期刊3篇、封面文章1篇）；申请发明专利6项（其中授权2项、国际3项），获中国建材科技奖（基础研究类）一等奖，组织承办第22届国际矿物学大会矿物材料分会和中国地质学会2019年学术年会矿物材料分会，在全国性学术会议上作大会（主题、邀请）报告8次。研究成果对于黏土矿物的高值化利用及功能矿物材料的开发具有重要的理论和实际价值。