【作者】 许春花；

【导师】 王文才；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2012， 硕士

【摘要】 海洋贻贝类黏性蛋白的发现，为材料表面改性提供了一种新方法。本论文主要利用多巴胺自聚合引入酚羟基和含氮官能团等功能基团，实现对玻璃纤维和针状硅酸盐纳米纤维的表面改性。然后，利用多巴胺辅助化学镀或聚多巴胺直接氧化还原方法制备镀银玻璃纤维和银/针状硅酸盐纳米纤维复合材料，从而实现在微纳米纤维上实现金属化。主要工作如下：(1)本论文提出了一种高效、环保的方法制备高导电镀银玻璃纤维。在有氧潮湿碱性条件下，将玻璃纤维放入配好的多巴胺溶液中，多巴胺就会氧化自聚合从而在玻璃纤维表面形成聚多巴胺层。含有酚羟基和含氮官能团的聚多巴胺既是银粒子和玻璃纤维的连接剂，又是将Ag+还原为单质银的还原剂。利用化学镀方法，在外加还原剂葡萄糖的作用下制备的镀银玻璃纤维，用X射线光电子能谱(XPS)，X射线衍射(XRD)，扫描电镜(SEM)和四探针分别表征玻璃纤维的表面元素组成，物相组成，表面形貌和电阻率。结果表明，金属态的银粒子致密均匀的沉积在玻璃纤维表面。通过改变硝酸银和多巴胺浓度可以得到银的质量分数为9.5-24%的镀银玻璃纤维，且镀银玻璃纤维的电阻率最低为1.0mΩ cm。（2）由微米级过渡到纳米级，本论文还研究了多巴胺改性针状硅酸盐纳米纤维，并利用聚多巴胺还原银离子制备银/针状硅酸盐纳米复合材料。一方面研究了多巴胺浓度和聚合时间对改性纳米纤维的影响，另一方面研究了外加还原剂，pH，温度和络合剂对银/纳米纤维复合材料的影响。用X射线光电子能谱(XPS)和傅立叶红外光谱(FTIR)对改性前后针状硅酸盐的表面元素组成和官能团进行表征，扫描电镜(SEM)观察改性纳米纤维的表面形貌，高分辨透射电镜(HRTEM)研究纳米纤维的微观形貌和微观结构，X射线衍射(XRD)表征纳米纤维的物相组成。结果表明当pH为8.5，反应温度为60℃时，单质纳米银粒子粒径为2.15nm且粒径分布均匀。本论文用多巴胺对无机纤维材料进行表面改性，并在此基础上采用化学镀、氧化还原法实现微米/纳米材料表面金属化，金属与材料表面具有牢固的结合力，为材料表面金属化提供一个新思路、新方法。更多还原

【Abstract】 The techniques to modify substrate surfaces are significant for manyindustrial and research applications. In this work，dopamine was used tomodification of glass fiber (GF) and fibrillar silicate nanofiber (FS) viadopamine self-polymerization to polydopamine (PDA) on the materialsurfaces. What’s more, silver-plating glass fiber and Ag/fibrillar silicatenanofiber were synthesized by PDA-assisting electroless plating or PDAoxidation reduction directly. The details of the work are as follows:(1) Highly conductive silver-coated GF was fabricated in an efficientand environment-friendly way. When the GF powder was immersed indopamine solution, an adherent self-polymerized PDA layer was formedon the GF surface. PDA acts as both a linker between GF and silvernanoparticles and a reducing agent for reducing silver ions to metallicsilver. The silver nanoparticles can be chemically bound to the catecholand amine functional groups in PDA by electroless plating using glucoseas reducing agent. Chemical and physical characterizations of thesilver-coated GF were carried out by using X-ray photoelectronspectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Four-point probe was used to study the electricalresistivity of the silver-coated glass fibers. The results indicated that thesilver coated on the GF surface was compact, uniform, continuous, and ina metallic crystal state. The silver content could be well controlled from9.5to24wt.%by adjusting the reduction conditions. The electricalresistivity of the silver-coated glass fibers could be as low as1.0mΩ cm.(2) The transition from micron to nanometer, in this work, a novelmethod was developed for the preparation of silver/FS nanocomposite, inwhich dopamine acts as both modification agent and reducing agent. Onthe one hand, the effects of dopamine concentration and polymerizationtime on the modified FS nanofiber were studied. On the other hand, theeffects of extra-reducing agent, pH, temperature and complexing agenton the Ag/FS nanocomposites were also studied. The surface elementalcomposition and functional groups of FS before and after dopaminemodification were characterized by using X-ray photoelectronspectroscopy (XPS) and fourier transform infrared spectrometer (FTIR),surface morphology of samples were characterized by scanning electronmicroscopy (SEM), microscopic morphology and structure of Ag/FS wasdetected by transmission electron microscope (TEM) or high resolutiontransmission electron microscope (HRTEM), phase composition ofsample was characterized by X-ray diffraction (XRD). The resultindicated that metal silver nanoparticles with mean diameter of2.15nm and narrow particle size distribution deposited on the FS, when the pH is8.5, temperature is60℃.In conclusion, this paper shows that dopamine is a versatile methodto functionalize the surface of inorganic materials, and the combination ofthe following electroless plating technique and redox method couldprepare surface metalized composites good adhesion between the metalwith the substrate.更多还原