【作者】 熊善新；

【导师】 王琪；

【作者基本信息】 四川大学 ， 材料学， 2004， 博士

【摘要】 模板合成是制备一维纳米阵列的有效方法之一。本文选取具有规整孔洞结构的阳极氧化铝膜为模板，通过原位聚合、溶胶—凝胶、热解等方法制备了一系列管径大小一致、排列规整有序、具有一定光、电、磁功能的微管和微丝，如聚苯胺微管、聚苯胺／二氧化钛双层微管、聚苯胺／二氧化钛纳米杂化丝、聚苯胺／四氧化三铁磁性微管、聚丙烯腈微管和碳微管。在模板合成中，模板孔洞可被看作是微反应器，在这个反应器中，除可制备单组分的有机或无机纳米材料外，通过结构设计和调控，还可实现聚合物与无机纳米粒子的复合和杂化，制备具有准一维结构(管状、丝状)、多重功能、有序排列的有机／无机纳米复合材料。本文分别研究了模板孔道受限空间内聚合产物的结晶结构及链结构的变化；复合微管及微丝的光、电、磁及光催化等性能；微管、微丝内有机相与无机相的相互作用及其对微管、微丝性能的影响；探讨了微管和微丝的形成机理；并实现了磁性微管在磁场中的定向排列，为制备具有光、电、磁等功能的纳米材料和器件提供理论和实验基础。 一、利用苯胺单体在模板孔洞中的原位聚合，制备了管径、长度一致，排列规整的聚苯胺微管。采用SEM、TEM、AFM、FTIR、UV-vis、EDS、XRD及SAED等手段表征了聚苯胺微管的形貌、结构和性能，研究了受限环境下聚合对聚苯胺结构和性能的影响。结果显示聚苯胺的管径和长度分别与模板孔洞的孔径和长度相当，并呈有序的阵列结构：分析聚苯胺微管的形成机理，认为和苯胺单体与模板孔道的静电相互作用及模板孔壁高的摘要目州幽幽匕目粤.目目国亘颐典里，比表面能有关;在受限空间中聚合，聚苯胺的分子链沿模板孔道方向取向，使其共辘度增加，红外特征吸收峰发生偏移，晶型由假正交晶型转变为更规整的六方晶型;XPS分析表明聚苯胺微管具有比其本体试样更高的掺杂度，这是由于聚苯胺微管极大的比表面积有利于掺杂及模板孔壁阻碍了掺杂剂挥发;FL分析证实聚苯胺微管具有光致发光现象，当PANI处于脱掺杂态时，荧光光谱会发生红移:经STM测试了单根聚苯胺微管的电学特性，结果表明聚苯胺微管具有非线性U一I特性，由于苯胺在受限空间内聚合使分子链取向，电导率增加，单根队Nl微管的电导率高于本体试样。 二、采用二步法得到了PANI/TIO:双层微管，先在模板孔道中原位聚合制备聚苯胺微管，再用溶胶一凝胶法在聚苯胺微管内制备二氧化钦微管。通过SEM、TEM和EDS表征了PANI/TIO:微管的双层结构，用FTIR、XRD、UV-vis、XPS和FL研究了PANI/Tio:双层微管的结构和光催化性能，结果表明，双层微管具有与PANI微管相同的尺寸和形貌，双层微管中PANI层与TIO:层间无强相互作用:由于量子效应及能隙匹配，UV及FL光谱中各特征峰发生了不同程度的蓝移;通过研究太阳光下甲基橙溶液的降解实验表征了双层微管的光催化性能，结果表明双层微管具有比二氧化钦微管更高的催化效率，这是由于双层微管中，处于外层的聚苯胺对里层的二氧化钦具有敏化作用，使二氧化钦对太阳光的吸收从紫外区扩展到可见区。 三、通过原位聚合和溶胶一凝胶法制备了高度有序排列的PANI/Tiq纳米杂化丝。经SEM、TEM和EDS表征，证实所制备的PANI/TIO:为丝状结构，其直径要小于模板孔洞的孔径，其原因是在溶胶一凝胶过程中，小分子和溶剂挥发产生体积收缩;微丝表面不光滑，表明PANI与Tio:发生微相分离;经FTIR、XRD、UV-vis、FL、STM、XPS和四探针等手段表征了PANI/TIO:杂化微丝的结构和光、「匕胜能，结果表明TIO:与PANI间存在一定的化学相互作用(Ti原子与N原子或H原子间形成键合作用)，由于相互作用导致样品uv、FTIR及FL光谱偏移;体系的电导率随TIOZ含量的增加下降，当TIO:含量为20%时，样品基本不导电;对单根微丝的电性能研究表明，其U一I曲线呈现非线性，山于TIO:的加入，单根杂化丝四川大学工学博士学位论文的电导率为0.035/cm，低于本体样。 四、将磁流体与苯胺单体引入模板孔洞进行聚合，制备了具有磁性的PANI/Fe30;复合微管。用SEM、TEM和EDS表征了微管的形貌，结果表明，纳米Fe3O;粒子均匀地分布在微管的管壁中，微管的尺寸与模板孔洞的尺寸相当;用FTIR、XRD、UV-vis、MFM和STM表征了PANI/Fe3O;微管的结构和光、磁性能，结果表明Fe304粒子与PANI间存在较强的化学作用，微管的磁力分布与模板孔洞的排列一致;对磁力图像分析发现，样品的磁性较小，平均相位差仅为0.8670，这是由于磁性颗粒被聚苯胺包覆及Fe304粒子在微管中含量较低造成的;通过将磁性微管分散液置于磁场中，可达到对磁性微管的定向排列，SEM照片显示只有尺寸较小的微管发生响应，也证实微管的磁性较弱。 五、通过将丙烯睛单体充入模板孔洞进行聚合制备了聚丙烯睛微管，然后将聚丙烯睛微管在惰性气氛中热解制备了碳微管。SEM、TEM及EDS显示两种微管的尺寸和形貌均与模板孔洞的尺寸和形貌一致;TEM显示碳微管具有独特的竹节状结构，其形成原因是由于聚丙烯睛降解产生的油状物在微管内堆积造成部分堵塞，继续升温时，管内的挥发物不能及时排出，碳化后形成竹节状结构;采用FTIR及XRD研究?更多还原

【Abstract】 Template synthesis technique is an efficient method for preparation of one-dimensional nanoarray. In this study, a series of microtubes and micro wires, which possess optical, electrical, magnetic function and bilayer structure, such as polyaniline (PANI) microtubes, PANI/TiO2 bilayer microtubes, PANI/TiO2 nanohybrid microwires, PANI/Fe3O4 magnetic microtubes, polyacrylonitrile (PAN) microtubes and carbon microtubes with regular structure and well-ordered arrangement were prepared through in-situ polymerization, sol-gel process and pyrogenation methods based on Anodic Aluminum Oxide (AAO) template. The channels of template can be viewed as "micro-reactor", in which organic or inorganic nanomaterial as well as hybrid and composites of polymer and inorganic nanoparticles were obtained through design of structure. The structure, morphology, optical, electrical, magnetic properties and interaction between organic phase and inorganic phase of microtubes and microwires were studied, and the oriented arrangement of magnetic microtubes was obtained in magnetic field.1. The highly ordered PANI microtubes array with same diameter and regular arrangement were prepared through in-situ polymerization of aniline monomer in the microchannels of AAO template. The morphology, structure and crystal of PANI microtubes were characterized with SEM, TEM, AFM, FTIR, UV-vis, EDS, XRD and SAED. Effect of confined environment on structure, morphology and properties of PANI microtubes was studied. The results showthat the diameter and length of PANI microtubes are closed to those of template channels, respectively. The formation mechanism of PANI microtube is that there are static electricity interactions between aniline monomer and pores wall of template and high surface areas of pores wall. The molecular chains of PANI can be oriented along the template channels, resulting in increase of conjugated degree of PANI molecular chains and shift of FTIR characteristic peaks of PANI, and transition of crystal form of PANI from pseudo-orthorhombic to hexagonal. XPS shows that the doping degree of PANI microtubes is higher than that of PANI bulk sample, due to huge surface area of PANI microtubes. The electrical property of single PANI microtube was measured with STM. The results show that the U-I curve of PANI microtube is non-linear. The conductivity of single PANI microtube is higher than that of PANI bulk sample due to the orientation of PANI molecular chains.2. PANI/TiO2 bilayer microtubes were prepared through two-step method: firstly, PANI microtubes were prepared through in-situ polymerization of aniline in template channels; secondly, TiO2 microtubes were prepared through sol-gel process in PANI microtubes. The bilayer structure of PANI/TiO2 microtubes was characterized with SEM, TEM and EDS. The structure and property of PANI/TiO2 bilayer microtubes were studied with FTIR, XRD, UV-vis and FL. The results show that bilayer microtubes possess the same size and morphology as PANI microtubes and there is not chemical interaction between PANI microtubes and TiO2 microtubes, the characteristic peaks of UV and FL of microtubes bluely shift, due to quanta effect and match of energy gap. The photocatalysis property of PANI/TiO2 microtubes was characterized through study of the decomposing of methyl orange under sunlight. The results show that the catalysis efficiency of bilayer microtubes is higher than that of TiO2 microtubes, because PANI can act as the sensitizer of TiO2, the sunlight absorption of TiO2 is extended from UV region to visible region.3. The PANI/TiO2 hybrid micro wires were prepared through in-situ polymerization and sol-gel process in template channels. The morphology and structure of hybrid microwires were characterized with SEM, TEM and EDS. The results show that the structure of PANI/TiO2 microwires is solid, different from hollow structure of PANI microtubes, the diameter of microwires is smaller than that of template channel, because some small molecular and solvent are volatilized, leading to volume shrinkage dur更多还原