MoS2 Loading Research Articles

Enhancement of mechanical and tribological properties in ring‐opening metathesis polymerization functionalized molybdenum disulfide/polydicyclopentadiene nanocomposites

AbstractThis study focuses on the possibility of improving performance properties of polydicyclopentadiene (PDCPD) nanocomposites for engineering applications using nanoparticles. In this article, molybdenum disulfide/polydicyclopentadiene (MoS2/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 MoS2 nanoparticles hybridized with dialkyldithiophosphate (PyDDP) were successfully prepared by in situ surface grafting method. The effect of low MoS2 loadings (<3 wt %) on the mechanical and tribological behaviors of PDCPD was evaluated. The results indicated that the friction coefficient of the MoS2/PDCPD nanocomposites was obviously decreased and the wear resistance of nanocomposites was greatly improved by the addition of PyDDP‐hybridized MoS2 nanoparticles; meanwhile, the mechanical properties were also enhanced. The MoS2/PDCPD nanocomposites filled with 1 wt % PyDDP‐hybridized MoS2 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 MoS2 nanoparticles, and modest increase in modulus and strength was also observed. The reinforcing and wear‐resistant mechanisms of MoS2/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 MoS2/PDCPD nanocomposites in very low MoS2 loadings. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

‘Ship-in-a-Bottle’ Synthesis of MoS2/MCM-41 Catalysts by Decomposition of Single Source Precursor in Mesoporous Channel

MoS2/MCM-41 catalysts have been prepared by thermal decomposition of MCM-41 with cetyltrimethylammonium thiomolybdate, which was synthesized by reaction between ammonium thiomolybdate and cetyltrimethylammonium bromide left in the pore channel of MCM-41. The obtained catalysts exhibit type IV adsorption–desorption isotherms, indicating that MCM-41 mesoporous structure is retained during the synthesis process. With increasing loading of MoS2, the catalytic activity of MoS2/MCM-41 for HDS of DBT first increases, followed by a leveling off above 10 % MoS2 loading, likely due to lack of accessibility to additional active sites. For the first time over MoS2 catalysts, the DDS (i.e., hydrogenolysis) reaction pathway is favored with 100 % selectivity. This unique performance is associated with single layer MoS2 sites stabilized within the pores of the MCM-41 support. MoS2/MCM-41 catalysts have been prepared by thermal decomposition of cetyltrimethylammonium thiomolybdate in MCM-41, which was synthesized by reaction between ammonium thiomolybdate and cetyltrimethylammonium bromide left in the mesoporous channel.