Degradation kinetics of organic-inorganic hybrid materials based on epoxy resin was investigated by thermogravimetric analysis (TGA). The hybrid materials were prepared from diglycidyl ether of bisphenol A (DGEBA) and 3-glycidyloxypropyltrimethoxysilane (GLYMO) polymerised simultaneously by poly(oxypropylene)diamine (Jeffamine D230). Nanometric level of homogeneity in the hybrids was verified b...

Ion chromatography (IC) developed by Small et al . [1] is widely recognized as a simple, powerful and convenient analytical technique for the determination of various low−molecular−weight ionic compounds [2, 3]. Firstly, IC with conductimetric detection (IC−CD) was mainly applied for the determination of inorganic anions. This is because a lightly sulfonated styrene−divinylbenzene co−polymer (S...

Size-controllablemonodisperse CdSe nanocrystals with different organic cappingwere prepared based on the hot-injectionmethod. The effective separation of nucleation and growthwas achieved by rapidlymixing two highly reactive precursors. As a contrast, we preparedCdSe/CdS nanocrystals (NCs) successfully based on the selective ion layer adsorption and reaction (SILAR) technique. This inorganic ca...

The preparation and the characterization of novel geopolymer-based hybrid composites are reported. These materials have been prepared through an innovative synthetic approach, based on a co-reticulation in mild conditions of commercial epoxy based organic resins and a metakaolin-based geopolymer inorganic matrix. This synthetic strategy allows the obtainment of a homogeneous dispersion of the o...

A procedure based on radiochemical neutron activation analysis was developed for the determination of chromium in biological materials. The procedure consists of irradiation of reference and test samples in a nuclear reactor, microwave sample digestion, selective and quantitative radiochemical separations of chromium and gamma-ray spectrometric measurement of 51Cr. Separation of chromium from t...

The isothermal enthalpy changes with time of a dental composite were examined by microcalorimetry to isolate the effects of different filler concentrations and curing times on chemical aging of these composites. Urethane dimethacrylate (UDMA) monomer, zirconia-silica (ZS) powder, and 3-methacryloxypropyltrimethoxysilane (MAPM) were used as organic and inorganic matrices, and a coupling agent, r...

This paper compared the effectiveness of four organic materials for decreasing the amounts of soil extractable Cr(VI) in Cr(VI)-contaminated soils using the DOWEX M4195 resin-extraction method. Organic matters were added into Cr(VI)-spiked soils [500 mg Cr(VI)(kgsoil)(-1)] in the form of sugarcane dregs compost (SCDC), cattle-dung compost (CDC), soybean meal (SBM) and rice bran (RB), in the amo...

In tundra, phosphorus (P) is an important macronutrient for plants and microorganisms. A major fraction of P exists as organic compounds in the topsoil which can be mineralized to bioavailable inorganic P. Since mineralization is positively related to temperature, climate warming is likely to increase P bioavailability but the extend of these changes may also depend on vegetation cover and soil...

The resin composites were introduced for the first time in dentistry in the mid-1960s, for the restoration of anterior teeth, because of the necessity to eliminate the shortcomings of the restorative materials existing at that time. Because of their properties, aesthetic aspect, adhesion to hard dental tissues, high values of the physico-mechanical properties, they play an important role in den...

BACKGROUND The isolation of highly pure copper-free methanobactin is a prerequisite for the investigation of the biogeochemical functions of this chalkophore molecule produced by methane oxidizing bacteria. Here, we report a purification method for methanobactin from Methylosinus trichosporium OB3b cultures based on reversed-phase HPLC fractionation used in combination with a previously reporte...