Stabilized nanograin boundaries in nickel-molybdenum alloys result in increased hardness with decreasing grain size.

Uniform dispersion of two-dimensional (2D) graphene materials in polymer matrices remains challenging. In this work, a novel layer-by-layer assembly strategy was developed to prepare a sophisticated nanostructure with highly dispersed 2D graphene oxide in a three-dimensional matrix consisting of one-dimensional bacterial cellulose (BC) nanofibers. This method is a breakthrough, with respect to the conventional static culture method for BC that involves multiple in situ layer-by-layer assembly steps at the interface between previously grown BC and the culture medium. In the as-prepared BC/GO nanocomposites, the GO nanosheets are mechanically bundled and chemically bonded with BC nanofibers via hydrogen bonding, forming an intriguing nanostructure. The sophisticated nanostructure of the BC/GO leads to greatly enhanced mechanical properties compared to those of bare BC. This strategy is versatile, facile, scalable, and can be promising for the development of high-performance BC-based nanocomposite hydrogels.

Single face centered cubic (fcc) phase nano-grained Ni-Mo alloys were fabricated by electrodeposition in aqueous citrate-ammonia electrolytes with different concentration of sodium molybdate (0.5–7 g/L) with the addition of a mixture of saccharin and 2-butyne-1,4-diol. The effect of the additives mixture on the surface morphology and roughness, composition and grain size of nano-grained Ni-Mo deposits was investigated. It is demonstrated that this additives mixture effectively reduced surface roughness by eliminating bumps and tiny holes. Additionally, the additives mixture significantly reduced the grain size, especially when the concentration of sodium molybdate is low. The minimum grain size achieved with the presence of additives mixture is 4.4 nm with a Mo content of 18.7 at.%. Energy dispersive spectroscopy results indicated that the mixture of additives has little influence on the composition of the derived nano-grained Ni-Mo alloy. Steady state partial polarization together with chronopotentiometry were employed to evaluate the modification of additives to the cathodic process. It is exhibited that electrochemical behavior with the presence of additives correlates well with their effect on composition and grain size of nano-grained Ni-Mo alloys.

We present a novel, efficient, and regioselective method for the rhodium-catalyzed direct C–H ortho-halogenation of anilines that involves a removable N-nitroso directing group. This method featured mild reaction conditions, wide substrate scope, good functional group tolerance and satisfactory yields. To maintain the high ortho-regioselectivity and conversion, increasing the steric hindrance of the solvent was critical. Preliminary mechanistic studies suggest that C–H activation may be involved in the rate-determining step.