| 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... |
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