THE presence of silica in blood, and the much larger amounts sometimes found in urine, indicate that silica is appreciably soluble in body fluids. The determination of such solubility, however, is a matter of considerable difficulty and different results have been obtained by various workers, owing to the operation of such variable factors as particle size, concentration of suspension, method o...

Despite intensive research efforts in the synthesis of binary colloidal crystals, the production of well ordered binary colloidal crystal films over large areas continues to be synthetically challenging. In this paper, we investigate the phase behavior of binary mixtures of l-arginine-stabilized 36 and 22 nm silica nanoparticles deposited as centimeter-scale thin films onto a vertical substrate...

UNLABELLED Thermus thermophilus HB8 expresses silica-induced protein (Sip) when cultured in medium containing supersaturated silicic acids. Using genomic information, Sip was identified as a Fe(3+)-binding ABC transporter. Detection of a 1-kb hybridized band in Northern analysis revealed that sip transcription is monocistronic and that sip has its own terminator and promoter. The sequence of th...

Epoxy-based nanocomposites were fabricated with different content of colloidal silica nanoparticles such as 10.0, 20.0 and 30.0 wt %, through solution casting. The covalent bonding interfaces, resulting from a ring-opening reaction between silica nanoparticles and epoxy matrix were confirmed by the Fourier transform (FT-IR) infrared spectroscopy. These nanocomposites were characterized for ...

A major challenge in the synthesis of porous metal oxides is the control of pore size and/or wall thickness that may affect the performance of these materials. Herein, nanoporous β-MnO₂ samples were prepared using different hard templates, e.g., ordered mesoporous silica SBA-15 and KIT-6, disordered mesoporous silica, and colloidal silica. These samples were characterized by Powder X-Ray Diffra...

We show a simple method to visualize the morphology of water adsorbed within the pore network of colloidal crystals made of submicrometer silica spheres. Water is replicated into silica by modified silicon tetrachloride hydrolysation under standard ambient conditions, making it visible to standard electronic microscopy and thus allowing one to discern the original water distribution. Different ...

Using liquid crystalline self-assembly of cellulose nanocrystals, we achieve long-range alignment of anisotropic metal nanoparticles in colloidal nanocrystal dispersions that are then used to deposit thin structured films with ordering features highly dependent on the deposition method. These hybrid films are comprised of gold nanorods unidirectionally aligned in a matrix that can be made of or...

We chose dipicolinic acid as a tridentate chelating unit featuring ONO donors to react with lanthanide(III) ions to yield tight and protective N(3)O(6) environments around the lanthanide(III) ions. We immobilized the lanthanide(III)-dipicolinic acid complexes on colloidal mesoporous silica with diameter smaller than 100 nm by a covalent bond grafting technique and obtained nearly monodisperse l...

Interaction forces between a fluorite (CaF2) surface and colloidal silica were measured by atomic force microscopy (AFM) in 1 x 10(-3) M NaNO3 at different pH values. Forces between the silica colloid and fluorite flat were measured at a range of pH values above the isoelectric point (IEP) of silica so that the forces were mainly controlled by the fluorite surface charge. In this way, the IEP o...

Nanofluids, colloidal suspensions consisting of base fluids and nanoparticles, are a new generation of engineering working fluids. Nanofluids have shown great potential in heat/mass transfer applications. However, their practical applications are limited by the high production cost and low stability. In this study, a low-cost agricultural waste, rice husk ash (RHA), was used as a silicon source...