Development of coated conductive nano-wires by use of self-organized block copolymers

合成了聚对苯乙炔(PPV)与聚乙二醇的嵌段共聚物。将共聚物溶液倒入PPV的好溶剂和聚乙二醇差的溶剂中，可诱导共聚物的自缔合。通过透射电子显微镜观察发现，形成了直径为10 nm、长度超过100 nm的纳米线。紫外光谱和荧光光谱表明PPV片段之间存在相互作用。研究还发现，嵌段共聚物能使PPV均聚物在四氢呋喃/水混合溶剂中形成的纳米线中增溶。还成功地合成了可作为自缔合材料的PPV和聚乙二醇酯的接枝共聚物。根据上述结果，通过调整组成和聚合物浓度等条件，可以制备出形状可调的纳米线。除了PPV基共聚物外，还研究了其他聚合物缔合作用。通过取代不同的烷基，成功地控制了聚酰胺基丙烯酸酯S的温敏聚集。合成了氨基甲酸酯改性的聚乙二醇酯和聚丙二醇聚醚(PPG)以及聚乙二醇/聚丙二醇酯共聚物，并对其在电场作用下的流变性能进行了详细的研究。这些聚醚的聚集状态可以随着电场的响应而可逆地改变，这表明这些聚合物是一种有用的电流变流体。这种氨基甲酸酯改性聚醚的水溶液具有独特的热敏性能。由于缔合结构的可控性，温度敏感型聚酰胺基丙烯酸烷基酯、S和聚醚可以作为纳米线的组成部分。

Block copolymers composed of poly(p-phenylene vinylene) (PPV) and poly(ethylene glycol) were synthesized. Pouring the copolymer solution into a polar solvent, which is a good solvent for PPV and a poor solvent for PEG, induced self-association of the obtained copolymers. Observation with a transmission electron microscope revealed the formation of nano-wires with the diameter of 10 nm and the length of more than 100 nm. The association of PPV segments was indicated from the UV and fluorescence spectroscopy. It was also found that the block copolymer could solubilize PPV homopolymer within the nano-wires formed in THF/water mixed solvent. Graft copolymers of PPV and PEG, which can be used as the self-association materials, were also successfully synthesized. From the above results, it is possible to prepare nano-wires having regulated shapes by adjusting the condition such as the composition and polymer concentration.Besides the PPV-based copolymers, other polymer associations were studied. The thermosensitive aggregation of poly(alkyl acylaminoacrylate)s was successfully controlled by replacement of various alkyl substituents. Urethane-modified PEG and other polyethers such as poly(propylene glycol) (PPG) and PEG/PPG copolymers were synthesized and the rheological properties under an electric field were examined in detail. The aggregation state of these polyethers can be reversibly changed in response to the electric field, which suggests the useful property of these polymers as an electrorheological fluid. Aqueous solutions of this kind of urethane-modified polyethers showed characteristic thermosensitive properties. The poly(alkyl acylaminoacrylate)s and polyethers responsive to temperature can be utilized as a component of nano-wires because of the controllability of association structures.