Copper nanoparticles on controlled pore glass (CPG) as highly efficient heterogeneous catalysts for “click reactions”

We herein report that supported copper nanoparticles (CuNPs) on commercially available controlled pore glass (CPG), which exhibit high mechanical, thermal and chemical stability as compared to other silica-based materials, serve as a useful heterogeneous catalyst system for 1,3-dipolar cycloadditions (“click” reactions) between terminal alkynes and organic azides under green chemistry conditions. The supported CuNPs-CPG catalyst exhibited a broad substrate scope and gave the corresponding triazole products in high yields. The CuNPs-CPG catalyst exhibit recyclability and could be reuced multiple times without contaminating the products with Cu.

Calorimetric Sensor for Ethanol Using Ni2+-nitrilotriacetic Acid (NTA) Resin Immobilized Alcohol Dehydrogenase (ADH)

Background: A simple, fast and economic analytical method for the determination of ethanol is important for clinical, biological, forensic and physico-legal purposes. Methods: Ni2+-NTA resin was used as an immobilization matrix for the simple one-step purification/ immobilization of his6-tagged ADH. Different alcohols with a concentration range of 0.5-50% V/V, namely methanol, ethanol and propanol were measured using prepared ADH enzyme thermistor. The ethanol content of Tsingtao beer was tested as a real sample containing alcohol. Reproducibility and stability of prepared ADH enzyme thermistor were also investigated by repeated measurements. Results: In comparison to the controlled pore glass (a common used support for the immobilization of enzyme) used in thermal biosensor, the use of Ni2+-NTA resin not only led to simple one-step purification/ immobilization by his6-tagged ADH binding to Ni2+-NTA resin, but also made the immobilizing supports reusable. The prepared biosensor can be used to determine ethanol and methanol by the calorimetric measurement. A linear range of 1 -32% (V/V) and 2-20% (V/V) was observed for ethanol and methanol, respectively. The detection limits were 0.3% (V/V) and 1% (V/V) for ethanol and methanol, respectively. The tested ethanol concentration of Tsingtao beer was 4.5% V/V, which is comparable with the labeled alcohol by volume (ABV) 4.80%. Conclusion: Ni2+-NTA resin, as an immobilization matrix in ET sensor, provides a simple one-step purification/immobilization for His6-tagged recombinase and a reusable immobilization matrix. The prepared biosensor exhibits good repeatability and stability. Such a new biosensor shows great promise for rapid, simple, and cost-effective analysis of ethanol and methanol, both in qualitative and in quantitative tests.

A Study on Structure and Phase Composition of Cellular Ceramic Materials from Dispersed Silica-Rich Rocks

Studies on structure, phase composition and properties of ceramic wall materials with a glass-crystalline framework from dispersed silica-rich rocks are described. The results of chemical, mineralogical and granulometric compositions of tripolite and granulated foam-glass crystalline material (GFGCM) are presented. The dependence of physical and mechanical properties of cellular ceramic materials on GFGCM content in the composition in the amount from 5 to 75% is determined. Test samples of cellular ceramic materials with dimensions 250 × 120 × 65 mm, having a compressive strength 16.2-20.8 MPa, water absorption 7.1-7.9 % and an average density 0.99-1.32 g/m3 were produced at the factory. At the macroscale level the cellular structure of the ceramic material consists of closed pores with a vitrified inner surface pore, glass-crystalline outer shell of the pores and solid phase of the framework walls. It was established that after firing in the temperature range 850-900 °C the walls of the framework are represented by quartz, feldspar and hematite, a pronounced halo is indicating a significant amount of glass phase.

Rapid and Efficient Method of Immobilization of Invertase on Long Chain Akylamine Controlled Pore Glass

ABSTRACT: Herein, we describe a quick method of immobilization of invertase onto photoreactive long chain alkylamine controlled pore glass (LCAA-CPG). Photorective LCAA-CPG which is prepared using microwave radiation holds at least one photoactivable functional group capable of forming a covalent bond with the biomolecule in a photochemical reaction. Invertase is subsequently immobilized onto Photorective LCAA-CPG using photochemical reaction.

Degradación del 2,5-DCP en agua destilada y en agua residual por los procesos de oxidación avanzada con ozono y ozono-UV combinados con un tratamiento biológico

In recent years, there have been increases in contamination of water supplies, due to the continuous discharge of wastewater from chemical and pharmaceutical industries, without them being properly treated to remove the refractory organic compound they may contain. These contaminants endanger the quality of surface and groundwater, the ecosystems, and the health of the world´s population. In view of these problems, the present work examined the effectiveness of combining ozone and ozone-UV processes with a biological treatment to increase biodegradability and reduce toxicity levels of the chlorophenolic compound, 2,5-dichlorophenol (2,5-DCP) and its oxidative intermediates. A comparative study was carried out in a glass bubble column reactor equipped with a fine-pore glass diffuser with a volumetric mass transfer kLa of 1.58 min-1. Each experiment was done using a 1.5 L volume of 2,5-DCP (3.07 mM) aqueous solution of distilled water and municipal wastewater, at pH 7 with an applied ozone dose of 22 mg min-1 and an oxygen-ozone flow rate of 0.7 L min-1. Additionally, a low mercury UV lamp with wavelength of 254 nm was used during ozone-UV treatments. The results obtained, showed that 2,5-DCP was completed degraded with an ozone dose of approximately 1.2 g h-1 in both solutions, treated with ozone and ozone-UV processes. The best results were obtained with the ozone-UV processes after 60 min of oxidation, showing that the addition of photolysis treatment (UV lamp intensity = 4 mW cm-2) to ozone, accelerated COD removal (75%), mineralization (53%) and biodegradability (BOD5/COD) of 2,5-DCP from 0.2 to 0.85 in the wastewater. The toxicity of 2,5-DCP and its oxidation by-products were monitored at different time intervals using activated sludge respiration inhibition tests. The test analyses showed that ozone and ozone-UV treatments were effective in reducing the toxicity of 2,5-DCP and its by-products, which were less toxic to the microorganisms in activated sludge (IC25 = 135 mg/L), than the untreated 2,5-DCP solutions (EC50= 50 mg/L). The results achieved in this work, showed that the presence of organic and inorganic matters in the wastewater, had a positive effect on the oxidation of 2,5-DCP, which support the potential use of ozone and ozone-UV processes for the treatment of effluent with high concentration of chlorophenols.