The outstanding mechanical properties of nanocarbon materials, especially carbon nanotube(CNT), make them one of the most promising reinforcing nanofillers for the high-performance lightweight structural material. However, the complicated but not eco-friendly surface functionalization processes(e.g. HNO_3 oxidation) are generally necessary to help disperse nanocarbon materials into epoxy or build chemical bonds between them. Herein, nitrogen doped carbon nanotube(NCNT) was used to replace CNT to reinforce the epoxy resin, and the mechanical properties of the NCNT/epoxy nanocomposite showed significant superiorities over the CNT/epoxy nanocomposites. The fabrication process was simple and environmentally friendly, and avoided complicated, polluting and energy intensive surface functionalization processes. Moreover, the NCNT/epoxy suspension exhibited a relative low viscosity, which was favorable for the subsequent application. The reinforcing mechanism of NCNT was also proposed. The present work gives out an easy solution to the preparation of a high-performance nanocomposite as a potential lightweight structure material.
Catalytic performance of phosphate-modified carbon nanotube(PoCNT) catalysts for oxidative dehydrogenation(ODH) of n-butane has been systematically investigated. The Po CNT catalysts are characterized by SEM, TEM, XPS and TG techniques. We set the products selectivity as a function of butane conversion over various phosphate loading, and it is found that the PoCNT catalyst with the 0.8% phosphate weight loading(0.8PoCNT) exhibits the best catalytic performance. When the phosphate loading is higher than 0.8 wt%, the difference of catalytic activity among the PoCNT catalysts is neglectable. Consequently, the ODH of n-butane over the 0.8PoCNT catalyst is particularly discussed via changing the reaction conditions including reaction temperatures, residence time and n-butane/O_2 ratios. The interacting mechanism of phosphate with the oxygen functional groups on the CNT surface is also proposed.
Yajie ZhangRui HuangZhenbao FengHongyang LiuChunfeng ShiJunfeng RongBaoning ZongDangsheng Su
A simple, economic, efficient and eco-friendly nanodiamond(ND) modifying method to reinforce the ND/epoxy composite for the industrialization of the high-performance ND/epoxy composite is always desired. In the present work, the ND was successfully modified only using aqueous ammonia through an easy-to-operate method by replacing the hydrogen atoms in the carboxyl group with ammonium ions.Ammonia, which is the only pollutant in the process, could be recycled. The modified ND/epoxy composite showed an overwhelming advantage over the neat epoxy or the ND/epoxy composite in storage modulus in their glassy state without any degradation of tensile strength, hardness and fracture toughness.
