Graphite oxide (GO) was prepared with graphite flakes, KMnO 4 , and a mixture of concentrated H 2 SO 4 /H 3 PO 4 by an improved green synthesis method. To obtain fully oxidized GO, an orthogonal array design L 9 was applied to select the optimum preparing conditions. The effects of the quantity of graphite, the quantity of KMnO 4 , reaction time, and temperature on the degree of oxidization of GO were evaluated by the orthogonal array design (OAD). The results show that the factors arranged in important order as the follows: reaction time, reaction temperature, the quantity of KMnO 4 , the quantity of graphite. Graphite oxide obtained at the optimal parameters by the improved method was characterized by UV-Vis, FT-IR, Raman spectrum, and XRD techniques, and compared with GO produced by the modified Hummers' method. The results indicate that the GO obtained by the improved green synthesis method has fewer defects in the basal plane and is more oxidized than the modified Hummers' method.

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This study focuses on the possibility of improving performance properties of polydicyclopentadiene (PDCPD) nanocomposites for engineering applications using nanoparticles. In this article, molybdenum disulfide/polydicyclopentadiene (MoS 2 /PDCPD) nanocomposites have been prepared by in situ ring-opening metathesis polymerization using reaction injecting molding (RIM) process. To enhance the interfacial adhesion between the fillers and PDCPD matrix, the surface modified MoS 2 nanoparticles hybridized with dialkyldithiophosphate (PyDDP) were successfully prepared by in situ surface grafting method. The effect of low MoS 2 loadings (<3 wt %) on the mechanical and tribological behaviors of PDCPD was evaluated. The results indicated that the friction coefficient of the MoS 2 /PDCPD nanocomposites was obviously decreased and the wear resistance of nanocomposites was greatly improved by the addition of PyDDP-hybridized MoS 2 nanoparticles; meanwhile, the mechanical properties were also enhanced. The MoS 2 /PDCPD nanocomposites filled with 1 wt % PyDDP-hybridized MoS 2 exhibited the best mechanical and anti-wear properties. The friction coefficient was shown to decrease by more than 40% compared to pure PDCPD by incorporating just 1 wt % hybridized MoS 2 nanoparticles, and modest increase in modulus and strength was also observed. The reinforcing and wear-resistant mechanisms of MoS 2 / PDCPD nanocomposites were investigated and discussed by scanning electron microscopy. The well interfacial compatibility between the particle/matrix interfaces played an important role for the improved mechanical and tribological properties of MoS 2 /PDCPD nanocomposites in very low MoS 2 loadings.

An efficient and cheap catalyst, montmorillonite supported Ru nanoclusters (Ru/MMT) were successfully prepared and explored for the hydrogen generation from alkaline NaBH 4 solution. The catalytic behavior and the kinetics of Ru/MMT catalyzed hydrolysis of alkaline NaBH 4 was studied detailedly by measuring the volume of generated hydrogen gas varying catalyst concentration and temperature. The relationship between the activation energy (Ea) of NaBH 4 hydrolysis reaction and Ru/MMT amount was constructed, and the minimum value was determined to be 49.6 kJ/mol, which was lower than the most reported Ru-based supported catalysts that have been reported in the open literatures. The higher catalytic activity of Ru/MMT was due to the more open frame of montmorillonite than the other inorganic supporters, which decreases the substrate inhibition in catalytic hydrolysis of NaBH 4 .