A simple, green, and efficient approach was used to synthesize 3,4-dihydropyrimidines derivatives. We showed that the application of the planetary ball milling method with a ball-to-reagent weight ratio of 8 for the Biginelli reaction provides 3,4-dihydropyrimidines derivatives with excellent yields (>98%) in a short reaction time from the one-pot, three-component condensation of aldehydes, eth...

The mechanochemical N-alkylation of imide derivatives was studied. Reactions under solvent-free conditions in a ball mill gave good yields and could be put in place of the classical solution conditions. The method is general and can be applied to various imides and alkyl halides. Phthalimides prepared under ball milling conditions were used in a mechanochemical Gabriel synthesis of amines by th...

A series of edge-selectively halogenated (X = Cl, Br, I) graphene nanoplatelets (XGnPs = ClGnP, BrGnP, IGnP) were prepared simply by ball-milling graphite in the presence of Cl2, Br2 and I2, respectively. High BET surface areas of 471, 579 and 662 m(2)/g were observed for ClGnP, BrGnP and IGnP, respectively, indicating a significant extent of delamination during the ball-milling and subsequent ...

We demonstrate a method to improve the promising hydrogen storage capabilities of ammonia borane by making composites with alkaline-earth metal hydrides using ball-milling technique. The ball-milling for the mixtures of alkaline-earth metal hydride (MgH2 or CaH2) and ammonia borane (AB) yields a destabilization compared with the ingredient of the mixture, showing the hydrogen capacity of 8.7 an...

The influence of feed size and pulp density on the specific rate of breakage of quartz was investigated. Plots of log fraction of feed remaining within the feed size interval against grinding time allowed the application of the first order grinding model to be examined. Substantial non-linearities were observed for all feed sizes due to environmental and material factors. For feed sizes above 1...

Solid solutions of Ag-Cu were prepared via ball milling process, for about 5-30 h. The Cu-20at%Ag and Cu-3.64at%Ag composition were investigated by X-ray diffraction technique. It was realized that the solid solubility level could be increased by increasing the initial solute content in the mixture. In addition, shifts in peak positions of silver and copper were observed with milling time. The ...

Ultrafine MgH₂ nanocrystalline powders were prepared by reactive ball milling of elemental Mg powders after 200 h of high-energy ball milling under a hydrogen gas pressure of 50 bar. The as-prepared metal hydride powders were contaminated with 2.2 wt. % of FeCr-stainless steel that was introduced to the powders upon using stainless steel milling tools made of the same alloy. The as-synthesized ...

Various procedures of mixing starting powders for hot-pressing α-SiAlON ceramics were studied. They included different milling methods (attrition milling, ball milling, and sonication), liquid medium (water, isopropyl alcohol, and pyridine), and atmospheres (ambient air and nitrogen). These mixing procedures resulted in markedly different densification behavior and fired ceramics. As the powder...