Synthetic amorphous silica (SAS) is one of the most commonly used nanomaterials. It is an authorized food additive and is also found in a wide variety of industrial and consumer products from polymers, paints, and textiles to toothpastes, detergents and cosmetics. Silica nanoparticles (NPs) also have great potential for a variety of other applications, including diagnostic and therapeutic appli...

Structural mechanisms in disordered materials like amorphous semiconductors and glasses can be explored with the activation-relaxation technique (ART). The application of a sequence of such mechanisms allows for the generation of well-relaxed structures. The method and its application in the study of the microscopic changes in amorphous silicon and silica glass are reviewed, and two recent impr...

The most acidic OH groups in silica-aluminas (zeolites, clays, amorphous silica-aluminas) can be made to react selectively with C(6)D(6) to give acidic OD groups; quantification by IR spectroscopy shows that differences in the overall Brønsted acidity of aluminosilicates are dominated by differences in the density of sites of similar acid strength.

The goal of the present study was to compare the drug release properties and stability of the nanoporous silica with different pore architectures as a matrix for improved delivery of poorly soluble drugs. For this purpose, three dimensional ordered macroporous (3DOM) silica with 3D continuous and interconnected macropores of different sizes (200 nm and 500 nm) and classic mesoporous silica (ie,...

A novel synthesis approach for silica-based nanotubes (NTs) was discovered in the purely inorganic system containing the molecular compounds OP(NH2)3, SP(NH2)3 and SiCl4 in evacuated and sealed silica glass ampoules. Without any solvent or structure directing template the amorphous NTs self-organise to form orthogonally ordered, 3D hyperbranched mesocrystals, exhibiting an interesting material ...

Although amorphous silica nanoparticles are widely used in the production of food products (e.g., as anticaking agents), there is little information available about their absorption and biological effects after oral exposure. Here, we examined the in vitro intestinal absorption and in vivo biological effects in mice of orally administered amorphous silica particles with diameters of 70, 300, an...

We predict the properties of the propagating and nonpropagating vibrational modes in amorphous silica (a-SiO2) and amorphous silicon (a-Si) and, from them, thermal conductivity accumulation functions. The calculations are performed using molecular dynamics simulations, lattice dynamics calculations, and theoretical models. For a-SiO2, the propagating modes contribute negligibly to thermal condu...

The effect of the local structure Co-doped amorphous silica on hydrogen transport property was studied with aim to improve high-temperature hydrogen-permselectivity microporous silica-based membranes.

In this review, we present our recent results for atomistic mechanisms of damage nucleation and growth and dynamic fracture in silica glass. These results have been obtained with multimillion-to-billion atom, parallel, molecular dynamics simulations of (1) the interaction and coalescence of nanovoids in amorphous silica subjected to dilatational strain and (2) the nucleation, growth and healing...