nano silica-h2so4 is an efficient and mild catalysis system for the regeneration of aldehyde from aldoximes. ketoximes are converted to amides by beckmann rearrangement in the presence of nano silica-h2so4. the reactions are carried out in solvent-free conditions under microwave irradiation (600 w) within 50-120 sec in good yields.

Introduction Sulfuric acid was first assessed to be carcinogenic in 1997 in a report of the World Health organization WHO (IARC). Based on this report, the Senate committee dealing with the control of harmful substances in the workplace submitted the first proposal justifying a lower occupational exposure limit [2].This proposal contained a list of many individual studies. In the investigations...

The superhydrophobic silica coating has a great performance of self-cleaning which can be applied in the field of energy saving, anti-icing, drag reduction, etc. In this paper, Trimethyltrimethoxysilane (MTMS) /Trimethylchlorosilan (TMCS) superhydrophobic silica coating with two-layer structure was dip-coated. Atomic force microscope (AFM) images show that the surface morphology of MTMS/TMCS si...

Nano-silica-bonded 3-n-propyl-1-sulfonic acid imidazolium chloride (nano-SB-[PSIM]Cl) was applied as a highly efficient, general and heterogeneous catalyst for one pot multi-component reaction of 2-naphthol, arylaldehydes, and thioacetamide leading to 1-thioamidolakyl-2-naphthols. All reactions proceeded with excellent yields in short times under solvent-free conditions. Our protocol w...

We have studied the hydration of sulfuric acid – ammonia and sulfuric acid – dimethylamine clusters using quantum chemistry. We calculated the formation energies and thermodynamics for clusters of one ammonia or one dimethylamine molecule together with 1–2 sulfuric acid and 0–5 water molecules. The results indicate that dimethylamine enhances the addition of sulfuric acid to the clusters much m...

This current study reviews the utilization of traditional extraction methods and latest findings in silica from agricultural wastes, particular, sugarcane bagasse, using inorganic acids to produce nano-silicon. The three key processes discussed detail include electrochemical, ball milling, sol–gel processes. bagasse has been identified as cheapest source producing potential raw material for pre...

The preparation of 5-bromo-2-naphthol (4) in three steps from 5-amino-2-naphthol (1) is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in ...

In this study, nanosilica particles were prepared from self-made silica gel under the protection of citric acid in situ complexation and ethyl acetate as latent reagent. The effects acetate, acid, reaction temperature, time on particle size studied. optimum process parameters determined follows: Vethyl acetate: Vsilica sol = 9:50, addition amount 3.64%, 8 h, temperature 70 °C. products characte...