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.

The effects of adding Nano-Silica particles on the compressive strength and water permeability of concrete and its comparison with that of Micro-Silica were investigated in this work. The effect of combination of Nano- silica and Micro-silica were also studied in this work, which resulted in an increase in compressive strength of concrete in comparison with other concrete specimens tested in th...

This study is focused on synthesis of nano-colloidal silica via alkaline water glass solution. Sodium ions of water glass were removed by cation exchanging in a resin column to obtain the silicic acid which was titrated to the solution of sodium silicate. Concentration of the colloidal silica and pH value of the solutions were controlled using different concentrations of alkaline sodium silicat...

The effects of adding Nano-Silica particles on the compressive strength and water permeability of concrete and its comparison with that of Micro-Silica were investigated in this work. The effect of combination of Nano- silica and Micro-silica were also studied in this work, which resulted in an increase in compressive strength of concrete in comparison with other concrete specimens tested in th...

The longevity of grouting has a significant effect on the safe and sustainable operation of many engineering projects. A 500-day experiment was carried out to study the long-term mechanical behavior of nano silica sol grouting. The nano silica sol was activated with different proportions of a NaCl catalyst and cured under fluctuating temperature and humidity conditions. The mechanical parameter...

In order to improve the erosion capacity of a supercritical carbon dioxide (SC-CO2) jet, the influence of a nano-silica additive on the rock erosion characteristics was experimentally investigated. By impinging the SC-CO2 jets with nano-silica mass fractions of 0 wt % (pure SC-CO2 jet), 3 wt %, 6 wt %, 9 wt %, 12 wt %, 15 wt %, and 18 wt % on specimens of red sandstone, the erosion volumes unde...

Lightweight concrete (LWC) is used in the construction of partition and panel walls framed structures because it reduces dead load acting on structure. Rubberized lightweight aggregate made by using waste rubber tyre chips as a partial replacement coarse which increases ductility, toughness minimizes impact effect concrete. The presence content decreases compressive strength bond strength, affe...