Thirteen different cement-clinker crystalline phases present in the lime-silica-alumina system have been systematically modeled using a simple and general force field. This constitutes a new type of approach towards the study of lime-silica-alumina systems, where the simpler and more transferable Lennard-Jones potential was used instead of the more traditional Buckingham potential. The results ...

Based on first-principles density-functional calculations, we present the structure and diffusion of boron in amorphous silica, as well as in crystalline silica for comparison purpose. We find that incorporation of a boron atom into the amorphous silica matrix results in various minimum-energy configurations with and without oxygen deficient centers, and also the B-related defects can undergo i...

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...

Stable amorphous calcium carbonate supported by mesoporous silica gel was successfully synthesized. The silica gel support is prepared through the hydrolytic polycondensation of ethyl silicate under suitable conditions. Laser scanning confocal microscopy (LSCM) observations reveal that the morphology of the products is branched with cruciform-like and flower-like structure. Raman spectroscopic ...

A two-part experiment using bubble rafts to analyze amorphous structures is presented. In the first part, the distinctions between crystalline and vitreous structures are examined. In the second part, the interface between crystalline and amorphous regions is considered. Bubble rafts are easy to produce and provide excellent analogy to recent research results on the atomic structure of silica g...

We employ atomistic molecular dynamics simulations to predict the alignment and anchoring strength of a typical nematic liquid crystal, 4-n-pentyl-4'-cyano biphenyl (5CB), on different forms of silica. In particular, we study a thin (~20 nm) film of 5CB supported on surfaces of crystalline (cristobalite) and amorphous silica of different roughness. We find that the orientational order at the su...

Surface modified amorphous nanoporous silica molecules with hydrophobic as well as hydrophilic character can be effectively used as therapeutic drug for combating chicken malaria in poultry industry. The amorphous nanosilica was developed by top-down approach using volcanic soil derived silica as source material. Amorphous silica has long been used as feed additive for poultry industry and cons...

Adsorption onto silica-based high surface area carriers is a long known method of improvement drug dissolution rate, which has been described in early 1970s [1]. Porous silica has many silanol groups on its surface and can be used as pharmaceutical excipient, since it is regarded nontoxic after oral application. Due to its porous structure and large specific surface area, porous silica has a gr...

Manganiferous rock varnish (desert varnish) is common in subtropical deserts, but coatings of amorphous silica glaze dominate rock surfaces of the same lithology and exposed to similar amounts of annual precipitation in the rain shadows of the large tropical shield volcanoes such as those in Hawaii. Lacking an explanation for this contrast, a two decade-long laboratory experiment tested importa...

Microcrystals of coesite and stishovite were discovered as inclusions in amorphous silica grains in shocked melt pockets of a lunar meteorite Asuka-881757 by micro-Raman spectrometry, scanning electron microscopy, electron back-scatter diffraction, and transmission electron microscopy. These high-pressure polymorphs of SiO(2) in amorphous silica indicate that the meteorite experienced an equili...