extensive application of silica nanoparticles (snps) in various industrial products has led to the development of silica extraction methodologies out of various waste products. rice husk is an agricultural waste with a high content of amorphous silica. however, the presence of metal ion impurities and unburned carbon in the rice husk content may present an adverse effect on product color and pu...

a new polymorph crystalline silica composition having uniform pore dimensions were synthesized by calcining a crystalline hydrated alkyl-ammonium silicate. the pore dimensions approximately were 6 angstrom for silicalite-1 and 11 angstrom for silicalite-2 units. the silicalite-1 was prepared hydrothermally at a ph of about 10 from a reaction mixture consist of water, amorphous silica and a quat...

Silica scaling potential from geothermal waters puts limits on to what extent the heat from the water can be extracted. Once the waters become over-saturated with respect to amorphous silica, the handling of such waters becomes problematic. Many methods have been proposed to address this problem. One of them is aging the geothermal waste water allowing monomeric silica in excess of amorphous si...

“Silica,” is a term which refers broadly to the mineral compound silicon dioxide (SiO2). Silica can be crystalline or amorphous. Crystalline silica is significantly more hazardous to employees than amorphous silica. In addition to causing the disabling and irreversible lung disease known as silicosis, crystalline silica has been classified as a human carcinogen by the International Agency for R...

in this study chemical method of dissolution-precipitation was applied to produce amorphous silica nanoparticles from rice straw ash (rsa), the waste material of rice cultivation. the morphology, particle size, structure and area of specific surface of synthesized amorphous silica nanoparticles were evaluated using transmission electron microscopy (tem), x-ray diffraction analysis (xrd) and bet...

Ice sheets play a more important role in the global silicon cycle than previously appreciated. Input of dissolved and amorphous particulate silica into natural waters stimulates the growth of diatoms. Here we measure dissolved and amorphous silica in Greenland Ice Sheet meltwaters and icebergs, demonstrating the potential for high ice sheet export. Our dissolved and amorphous silica flux is 0.2...

Amorphous silica particles, whose applications are increasing in many biomedical fields, are known to be less toxic than crystalline silica. In this study, the inflammatory effects of amorphous silica nanoparticles were investigated using 30-nm amorphous silica nanoparticles and human peripheral blood mononuclear cells (PBMCs) or purified monocytes. As a result, production of IL-1β and IL-8 wer...

BACKGROUND Inhalation of crystalline silica is known to cause an inflammatory reaction and chronic exposure leads to lung fibrosis and can progress into the disease, silicosis. Cultured macrophages bind crystalline silica particles, phagocytose them, and rapidly undergo apoptotic and necrotic death. The mechanism by which particles are bound and internalized and the reason particles are toxic i...

Silica scaling is probably the principal factor limiting the extraction of energy from high temperature geothermal systems. Silica exists in a number of polymorphs from quartz through to opal A (or amorphous silica). The thermodynamics of the solubility of quartz and amorphous silica with variations in temperature, salt content, pH and pressure are discussed. However, in silica saturated geothe...