| One-dimensional nanomaterials, such as nanowire, nanotube and nanocable, have attracted increasing attention due to their novel optical, electronic, magnetic, chemical and good mechanical properties. Polymer nanotube is another heat point besides carbon nanotube. Various kinds of methods have been developed to prepare one-dimensional nanomaterials. Template method is proved to be very effective. In this thesis, the wetting template method, based on porous anodic aluminum oxide (AAO) membranes, has been used to fabricate several kinds of one-dimensional nanomaterials, including polymer nanotubes, metal nanowires and polymer enveloping metal coaxial nanocables. Their structures, properties have been characterized, and the mechanisms of difference methods have been tentatively studied. 1. Polymer nanotubesMore than 10 normal relative molecular mass polymer nanotubes and nanowires, such as PS, PA6, PP, PA66, PU, PRSN-130, PCL and ABS, etc., and their arrays were fabricated by simple physical techniques in the AAO templates with polymer solution and melt.(1) PS nanotubes with array was prepared by depositing a solution or melt of a high molecular weight PS (BASF) within the 200nm pores of anodic aluminum oxide (AAO). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM) were used to investigate their morphology and structures. These results illuminated that PS tubules weresuccessfully obtained and the wall thickness of PS nanotubes prepared by the 2.5wt%, 5.0wt% and 10.0wt% PS solution were respectively 50, 70 and 80 nm . The structure of polymer nanotubes depends strongly on the concentration of PS solution. The nanotubes made by 2.5wt% solution contain defects in its walls. Otherwise, the nanotubes by 5.0 wt% and 10.0 wt% solution are intact. The wall thickness of nanotubes from PS melt is about 110 nm. As to solution methods, the arrayed polymer nanotubes are easily prepared by the "down-to-up " wetting method, a simple solution wetting method.(2) The preparation of PA6, PP and PA66 nanotubes has not been reported. Template wetting method was, at the first time, applied to fabricate these nanotubes with polymer solution. PA6, PP and PA66 nanotubes and nanowires were, respectively, prepared at the different temperature. PP and LDPE nanotubes were successfully obtained by melt method. Based on the above result, the new viewpoint is raised that the polarity of polymer has much less influence on wetting process than the high surface energy of AAO template.(3) The bending modulus of polymer nanotubes was characterized by advanced AFM technique at the first time. PS nanotube's bending modulus is 0.7 GPa.(4) PS, PA6 and PA66 nanotubes were characterized by TGA and DTA. The results indicated that polymer nanotubes have better anti-oxidation and anti-pyrogenation properties than their bulk polymer. In addition, polymer nanotubes have good anti-solvent properties.(5) Based on the results of testing properties, we can deduce that the array of the molecular chain in the wall of polymer nanotubes is different from normal bulk polymer. Further, it verifies the Martin's conclusion that the polymer chains in the microcrystallites are oriented perpendicularly to the long axis of the nanotubes and the pore walls of the template.(6) At the first time, we put forward multi-layer wetting mechanism of polymer solution and critical value principle of polymer melt and drew its model graphs.2. Metal nanowiresPt, Fe and Au nanowires have been prepared by electrochemical deposition method.
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