Methyltrioxorhenium (MTO) Catalysis in Epoxidation of Alkenes: A Synthetic Overview

Epoxidation of alkenes is one of the most explored reactions in organic synthesis because of the accessibilities of diverse important compounds from epoxides. Several transition-metal-catalysts in combination with oxidizing agents...

Solid Propellant Formulations: A Review of Recent Progress and Utilized Components

The latest developments in solid propellants and their components are summarized. Particular attention is given to emerging energetic binders and novel, ‘green’ oxidizing agents and their use in propellant formulations. A brief overview of the latest reports on fuel additives is included. Finally, a summary of the state of the art and challenges in its development are speculated on.

A Purified Alkaline and Detergent-Tolerant Lipase from Aspergillus fumigatus with Potential Application in Removal of Mustard Oil Stains from Cotton Fabric

In the present study, the lipase from Aspergillus fumigatus was purified which was found to be stable to commercial detergents and oxidising agents. A purification fold of 6.96 and yield of 11.03% were achieved when the enzyme was purified using Octyl Sepharose column chromatography. In presence of various oxidizing agents, the highest activity of lipase was 15.56 U/mg with hydrogen peroxide. Among various surfactants used, the maximum activity exhibited by lipase was with Tween 80. While studying the effect of various detergents, the highest activity of 9.3 U/mg was achieved with "Vanish" detergent. Wash performance was studied with various detergents out of which "Vanish" showed highest oil removal of 79%. Lipase from Aspergillus fumigatus possessed better stability with various surfactants and oxidizing agents. The results of this study have shown that the lipase from Aspergillus fumigatus along with detergent "Vanish" (0.7%) under optimized conditions (5 μg/ml lipase, 40°C wash temperature and 40 min wash duration) improved oil removal from cotton fabric stained with mustard oil by 84%.

Facile and versatile ligand analysis method of colloidal quantum dot

Colloidal quantum-dots (QDs) are highly attractive materials for various optoelectronic applications owing to their easy maneuverability, high functionality, wide applicability, and low cost of mass-production. QDs usually consist of two components: the inorganic nano-crystalline particle and organic ligands that passivate the surface of the inorganic particle. The organic component is also critical for tuning electronic properties of QDs as well as solubilizing QDs in various solvents. However, despite extensive effort to understand the chemistry of ligands, it has been challenging to develop an efficient and reliable method for identifying and quantifying ligands on the QD surface. Herein, we developed a novel method of analyzing ligands in a mild yet accurate fashion. We found that oxidizing agents, as a heterogeneous catalyst in a different phase from QDs, can efficiently disrupt the interaction between the inorganic particle and organic ligands, and the subsequent simple phase fractionation step can isolate the ligand-containing phase from the oxidizer-containing phase and the insoluble precipitates. Our novel analysis procedure ensures to minimize the exposure of ligand molecules to oxidizing agents as well as to prepare homogeneous samples that can be readily analyzed by diverse analytical techniques, such as nuclear magnetic resonance spectroscopy and gas-chromatography mass-spectrometry.

Iron-Manganese Bimetallic-Organic Framework as A Photocatalyst for Degradation of Rhodamine B Organic Dye Under Visible Light

In recent years, there have been many research works on use of different methods to treat textile dyeing wastewater such as mechanical, biological and chemical methods (using oxidizing agents, such as: H2O2, O3, and H2O2/O3). However, some traditional textile dyeing wastewater treatment methods such as mechanical and biological methods have limitations in treating these pollutants thoroughly. To enhance the treatment efficiency, the use of photocatalysts combination with strong oxidizing agents, such as H2O2, has been extensively developed in recent years. In this study, the iron-centred bimetallic organic framework Fe-MOF has been synthesized by partial replacement of Fe3+ ions with Mn metal ions by solvent-thermal method. The analytical methods used to evaluate the structural characterization of the as-synthesized materials including Scanning Electron Microscope (SEM), Brunaurer-Emmett-Teller (BET), X-ray Diffraction (XRD), Fourier Transform Infra Red (FT-IR), and UV-Vis Diffuse Reflectance Spectroscopy (DRS). The experiments on the decomposition of organic pigment Rhodamine B were performed under varying conditions of pH, catalyst mass and RhB colorant concentration. Experiments with different electron capturers indicate that h+ plays a major role in the photochemical degradation of RhB. The stability and durability of the 0.1 Mn/Fe-MOF catalyst were evaluated through the leaching and recycle experiments, showing that the RhB degradation efficiency of the photocatalyst decreased modestly after five repetitions. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Enzymatic and Oxidizing Agents for the Decomposition of Polymers Used in the Composition of Drilling Muds

The article presents the results of research on the influence of enzymatic and oxidizing agents on polymers used in drilling mud technology. The research used calcium hypochlorite, urea peroxide, sodium persulfate, amylase and cellulase. This allowed us to determine the optimal concentrations of these agents in order to reduce the rheological parameters of drilling muds. The ability of enzymes and oxidants to decompose colloids used in the composition of drilling muds was determined on the basis of measurements of their rheological parameters and the influence of oxidants and enzymes on the properties of filter cakes. The final effect of the presented research was the development of a drilling mud treatment method before the cementing procedure and the development of washer fluids containing enzymatic or oxidizing agents to be used to prepare the borehole for the cementing procedure. The drilling muds selected for the research contained starch and cellulose polymer colloids, which allowed for the selection of appropriate agents depending on the type of polymer set used in the drilling mud. Positive results were obtained regarding the possibility of thinning the drilling mud immediately before cementing, as well as the possibility of using oxidants and enzymes in the composition of washer fluids.