A hierarchical zeolite CaA with microporous, mesoporous and macroporous structure was hydrothermally synthesized by a ”Bond-Blocking” method using organo-functionalized mesoporous silica (MS) as a silica source. The characterization by XRD, SEM/TEM and N2 adsorption/desorption techniques showed that the prepared material had well-crystalline zeolite Linde Type A (LTA) topological structure, mic...

Cancrinite, sodalite, and zeolite A have been found to form upon contacting hyperalkaline simulated tank waste (STW) with vadose zone sediments from the Hanford Reservation. Here, soluble silica and STW are used to study mineral formation and transformation. Two Hanford sediment fractions (diameters <50 and >50 lm instead of soluble silica) are also used as silica sources for comparison. A seri...

doi: 10.7185/geochemlet.1510 Glacial meltwater runoff is likely an important source of limiting nutrients for downstream primary producers. This has particular significance for regions surrounding the Greenland Ice Sheet, which discharges >400 km3 of meltwater annually. The Arctic is warming rapidly but the impact of higher discharge on nutrient export is unknown. We present four years of hydro...

Wild animals, pets, zoo animals and mammals of veterinary importance heavily suffer from trypanosomiasis 1 . Drugs with serious side effects are currently mainstay of therapies used by veterinarians. Trypanosomiasis is caused by Trypanosoma sp. leading to sleeping sickness in humans. Surface modified (hydrophobic and lipophilic) amorphous nanoporous silica molecules could be effectively used as...

The expression of 10 genes implicated in regulation of the inflammatory processes in the lung was studied after exposure of alveolar macrophages (AMs) to silica in vitro or in vivo. Exposure of AMs to silica in vitro up-regulated the messenger RNA (mRNA) levels of three genes [interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-2 (MIP-2)] withou...

Graphene quantum dots (GQDs) represent an important class of luminescent quantum dots owing to their low toxicity and superior biocompatibility. Chemical functionalization of GQDs and subsequent combination with other materials further provide attractive techniques for advanced bioapplications. Herein, we report the facile fabrication of fluorescent organosilane-functionalized graphene quantum ...

The study of preparing silica/rubber composites used in tires with low rolling resistance in an energy-saving method is fast-growing. In this study, a novel strategy is proposed, in which silica was modified by combing alcohol polyoxyethylene ether (AEO) and 3-mercaptopropyltriethoxysilane (K-MEPTS) for preparing silica/natural rubber (NR) master batches. A thermal gravimetric analyzer and Rama...

Al/MgAl2O4in situ metal matrix composites have been synthesized using value-added silica sources (microsilica and rice husk ash) containing ∼97% SiO2 in Al-5 wt.% Mg alloy. The thermodynamics and kinetics of MgAl2O4 formation are discussed in detail. The MgO and MgAl2O4 phases were found to dominate in microsilica (MS) and rice husk ash (RHA) value-added composites, respectively, during the ini...

BACKGROUND Silicon dioxide composites have been found to enhance the mechanical properties of scaffolds and to support growth of human adipose tissue-derived stem cells (hADSCs) both in vitro and in vivo. Silica (silicon dioxide alone) exists as differently sized particles when suspended in culture medium, but it is not clear whether particle size influences the beneficial effect of silicon dio...

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...