Abstract:To enhance the physical properties of copolymer-polyamide (CO-PA), a sequence of nanocomposites based upon CO-PA and chemically reduced graphene oxide (CRGO) nanoplatelets were prepared by in-situ reduction using hydrazine hydrate. Graphene oxide (GO), prepared by the improved Hummers method, was used to fabricate CRGO nanaoplatelets. Atomic-force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis showed that the thickness and the width of GO was about 0.9 nm and 1 μm, respectively. An abundance of oxygen-containing functional groups were introduced onto the GO sheets. XRD and SEM analysis showed that CRGO nanoplatelets were well dispersed in the CO-PA matrix with the appropriate CRGO content. TGA and DSC analysis demonstrated that CRGO nanoplatelets can significantly improve the thermal stability, glass-transition temperature, crystallization temperature of the composites. The mechanical properties of the nanocomposites were improved significantly with the appropriate increment of CRGO nanoplatelets content, though the elongation at break of the composites decreased with the increase of CRGO nanoplatelets content. The electrical conductivity test showed a significant increase in electrical conductivity from an insulator to almost a semiconductor with increasing CRGO nanoplatelets content. And at 1.0 wt% CRGO content, the electrical percolation threshold of the nanocomposites was found.

摘要: 采用一步水热法合成了 Cu 纳米粒子负载二氧化钛纳米管材料. 利用透射电子显微镜(TEM)、 X 射线衍 射仪(XRD)、 能谱仪(EDS)等对材料的相组成、 形貌以及形成过程进行了研究. 制得的 Cu-TiO2复合纳米材料长 度约为 100 nm, 直径 10-15 nm, 其上负载的 Cu 纳米粒子尺寸约为 5 nm. BET 比表面积测试表明实验制备的 Cu-TiO2复合纳米管的比表面积为 154.67 m 2 •g-1. 通过调节水热反应时间和钛前驱体种类, 研究了该复合纳米 管材料的形成机制. 结果表明: 非晶态的钛源对于成功一步合成 Cu-TiO2复合纳米管至关重要. 同时, 实验中观 察到铜纳米粒子的尺寸随水热反应时间延长而减小(反奥氏陈化过程), 这一现象有助于纳米粒子的可控合成. 紫外-可见吸收光谱表明该复合纳米管在 350-800 nm 范围内有较强的吸收, 并在 550-600 nm 范围观察到 Cu 的表面等离子激元吸收带. Cu-TiO2界面处形成的肖特基势垒有助于加快光生载流子的输运, 提高光生电子-空 穴对的分离效率. 光催化实验表明 Cu-TiO2复合纳米管在可见光下具有较高的催化活性.

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