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 effect of different parameters including: nano silica content, curing temperature, type of hardener, and flash-off time on mechanical and optical properties of polyurethane PU based clearcoat was investigated via standard Taguchi L9 method. Dispersion of nano silica in the resultant nanocomposites was explored by scanning electron microscopy SEM. SEM images showed a fine dispersion through ...

Abstract Self compacting concrete (SCC) is a new construction material in the world. The aim of this research is to construct self compacting concrete with high compressive strength using combination of nano silica and micro silica. For this purpose, nano silica, micro silica, Portland cement type 2, superplasticizer (SP), and gravel and sand have been used. Three different groups of samples wi...

A nano-composite powder composed of silica and carbon with a unique property could be prepared from a mixture of a silicate compound and an epoxy compound, in which the silica within the nano-composite powder has a BET surface area of as high as greater than 800m2/g although the nano-composite powder has a BET surface area of less than 10m2/g. It was estimated that the silica and the carbon are...

A variety of nano-carriers, nano-particles, nano-fibers, nano-tubes etc. have displayed greater competence to mimic nanoscale environment for the enzyme as compared to microand macro-environments provided by traditional support carriers that have been commonly employed for enzyme immobilization. The porous structured beads (silica, alginate etc.), membranes and fibers (>100 μm) have some inhere...

nanotechnology is a favorite research area that revolutionized mechanical and chemical properties of materials. recently, focusing on concrete as a porous material with micro-scale and nano-scale pores enthusiastic researchers developed their investigations to find out microstructure and mechanical properties of concrete. the aim of this paper is to investigate the effect of nano-silica as an a...

nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. the catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. the size of nanoparticles were observed with sem.all prepared compounds w...

Revision of the opinion on Silica, Hydrated Silica, and Silica Surface Modified with Alkyl Silylates (nano form)