Ionic liquids-assisted greener preparation of silver nanoparticles

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Effect of a novel green modification of alumina nanoparticles on the curing kinetics and electrical insulation properties of epoxy composites

A novel green surface modification was successfully implemented on alumina nanoparticles using chitosan (CS) to prevent nanoparticles' aggregation. To evaluate the surface changes of nanoparticles, FTIR, TGA, TEM, and SEM analyses were used. The cure kinetics of the uncured samples was analyzed by DSC. Different methods such as KAS, Friedman, Starink, and FWO were applied to measure the activation energy. The activation energy of epoxy reinforced with chitosan-functionalized alumina (epoxy/[CS-EPO-alumina]) was less than that of epoxy reinforced with alumina (epoxy/alumina), which was a confirmation of the positive effect of CS on curing reaction kinetics. Using the Malek method, the Sestak-Berggren autocatalytic equation was chosen to investigate the cure kinetics of the epoxy. It was found that the Sestak-Berggren equation is well matched with the experimental data and the model was suitable to predict the epoxy curing reaction reliably. Moreover, the glass transition temperatures of all samples were approximately the same. The effect of surface modification of alumina on the electrical insulating behavior of epoxy was also studied. It was found that CS functionalized alumina (CS-EPO-alumina) increased volume resistivity of epoxy at a temperature range of 30 to 80°C more than that of alumina. Electric stability and breakdown strength of epoxy/alumina and epoxy/(CS-EPO-alumina) also enhanced, where epoxy/(CS-EPO-alumina) experienced a further increase compared to epoxy.     

Experimental and theoretical studies on protecting steel against 0.5 M H2SO4 corrosion by new schiff base

In this study, a novel green corrosion inhibitor called 2,2'-((1Z,1′Z)-((piperazine-1,4-diylbis(2,1-phenylene))bis(methanylylidene))bis(azanylylidene)) (PMA) has been tested against corrosion of carbon steel in 0.5 M H₂SO₄. Quantum and electrochemical methods were used to evaluate PMA's ability to inhibit the deterioration of carbon steel in an acidic environment. The results revealed that PMA acted as a mixed inhibitor, primarily anodic, whose inhibition action was enhanced by increasing its concentration. At 298.15 K, the maximum efficiency was around 91% with 1 × 10^?3 M PMA in 0.5 M H₂SO₄. The results showed that the inhibition occurred due to adsorption of the PMA molecules on the surface. The adsorbed layer of PMA satisfied the Langmuir adsorption isotherm. The morphology of the surface was examined using scanning electron microscopy.     

Ethylenediamine functionalized magnetic graphene oxide (Fe3O4@GO-EDA) as an efficient adsorbent in Arsenic(III) decontamination from aqueous solution

Research on Chemical Intermediates - Magnetic graphene oxide nanocomposite functionalized with ethylenediamine (Fe3O4@GO-EDA) was synthesized as a recyclable nanoadsorbent for As(III)...     

Modification of WS2 nanosheets with beta-cyclodextrone and N-isopropylacrylamide polymers for tamoxifen adsorption and investigation of in vitro drug release

In this research, tungsten disulfide (WS₂) nanosheets were modified with beta-cyclodextrone (βCD) N-isopropylacrylamide polymers (NIPAAP) for adsorption of tamoxifen (TAM) drug. The synthesized WS₂/βCD/NIPAAP samples were characterized by field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) analyses. The adsorption experiments of TAM on WS₂/βCD/NIPAAP were performed as a function of pH, reaction contact time, temperature and drug concentration. The adsorption kinetic data were well fitted to the pseudo-second-order model. Also, the equilibrium data were well described by Langmuir isotherm model. The maximum adsorption capacity of WS₂/βCD/NIPAAP for TAM drug was found to be 62.0 mg/g. The results of regeneration tests showed that the synthesized WS₂/βCD/NIPAAP adsorbent can be easily reused after 6 cycles of adsorption–desorption. Furthermore, TAM drug release was investigated in a simulated system with pH 7.4 at different temperatures. The results showed that the release of TAM drug from WS₂/βCD/NIPAAP carrier at 50 °C and 37 °C was greater than TAM release at 25 °C. Also, the experimental data of drug release were studied by Higuchi, Ritger-Peppas, zero-order and first-order models. The release data were well fitted to the zero-order model indicating a case II transport. The results showed a high stability for TAM drug.

     

Electrochemical Sensor Based on Magnetic Fe3O4–Reduced Graphene Oxide Hybrid for Sensitive Detection of Binaphthol

Russian Journal of Electrochemistry - Naphthol is an environmental pollutant with highly toxic and corrosive. Naphthol can be absorbed by the body easily through the skin, and can cause serious...     

Functionally substituted alkylbenzotriazoles: Reactivity of alkylbenzotriazoles toward electrophilic and nucleophilic reagents

The reactivity of benzotriazolylacetone toward a variety of carbon and nitrogen electrophiles is reported. Several novel azolylbenzotriazoles as well as benzotriazolyl‐cinnolines have been synthesized. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:141–145, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10009