Synthesis and Characterization of Electrical and Thermal Conductive Vinyltriethoxysilane Functionalized Graphene Oxide/Poly (Methyl Methacrylate) Nanocomposite Films

The present study is an attempt to improve thermal, mechanical and electrical properties of poly (methyl methacrylate) (PMMA). For this purpose, vinyltriethoxysilane (VTES) was grafted covalently on the surface of graphene oxide (GO). This VTES functionalized graphene oxide (VGO) was dispersed in the PMMA matrix using the solution casting method. The morphology of the resultant PMMA/VGO nanocomposites was analyzed by SEM indicating well-dispersed VGO in the PMMA matrix. Thermal stability, tensile strength and thermal conductivity increased by 90%, 91% and 75%, respectively, whereas volume electrical resistivity and surface electrical resistivity reduced to 9.45 × 10⁵ Ω/cm and 5.45 × 10⁷ Ω/cm², respectively.

Synthesis, In Vitro α-Glucosidase Inhibitory Activity and Molecular Docking Study of New Benzotriazole-Based Bis-Schiff Base Derivatives

This study was carried out to synthesize benzotriazole-based bis-Schiff base scaffolds (1-20) and assess them in vitro for α-glucosidase inhibitory potentials. All the synthetics analogs based on benzotriazole-based bis-Schiff base scaffolds were found to display an outstanding inhibition profile on screening against the α-glucosidase enzyme. The synthetic scaffolds showed a varied range of inhibition profiles having IC₅₀ values ranging from 1.10 ± 0.05 µM to 28.30 ± 0.60 µM when compared to acarbose as a standard drug (IC₅₀ = 10.30 ± 0.20 µM). Among the series, fifteen scaffolds 1-3, 5, 6, 9-16, 18-20 were identified to be more potent than standard acarbose, while the five remaining scaffolds 4, 7, 8, 16, and 17, also showed potency against the α-glucosidase enzyme but were found to be less potent than standard acarbose. The structure of all the newly synthesized scaffolds was confirmed using different spectroscopic techniques such as HREI-MS and ¹H- and ¹³C- NMR spectroscopy. To find a structure-activity relationship, molecular docking studies were carried out to understand the binding mode of the active inhibitors with the active sites of the enzyme and the results supported the experimental data.

Synergistic Extraction of Europium (III) using Di-n-Butylsulfoxide and PicrolonicAcid

AIM AND OBJECTIVE

Europium (Eu(III))isa rare-earth metal, the softest, least dense, and most volatile member of lanthanides. It is greatly applied in control rods of nuclear reactors. Although various extraction methods of Eu(III)have been reported, we present a novel mixture ofeasily available extractants in optimizedexperimental conditions to extract it efficiently, quickly, and cost-effectively.

MATERIALS AND METHODS

Physical-chemical conditions (e.g. pH, equilibration time, temperature, europium concentration, extractants concentration, presence of specific metal ions) were optimized. The extractantspicrolonic acid (HPA) and di-n-butylsulfoxide (DBSO) were thoroughly mixed at equal concentrationin chloroform. Standard Eu(III) solution was used for method accuracy.Reagent blank was prepared under identical conditions but without metal ions.Using the metallochromic dye arsenazoIII as blank, absorbance of Eu(III) was measured spectrophotometricallyat 651 nm. Distribution ratio (i.e.Eu(III) concentration in aqueous phase before and after extraction) defined the extraction yield.

RESULTS

HPA/DBSO mixture (0.01 M)had a synergistic effect on Eu(III) extraction (1.19×10-5 mole/dm3) achieving a maximum yield (≥99%) at pH2, during 5 minutes equilibration,atroom temperature.Eu(III) extraction was reduced depending on the nature but not on the metal ions concentration. Extractants could be recycled four times without consequent degradation. Deionized water (dH2O) was the best strippantbesides its availability and low-cost. The composition of the extracted adduct was defined as Eu(PA)3.2DBSO.

CONCLUSION

This alternative method was stable, simple, rapid, cost-effective, reliable, accurate and sensitive.It could be used forEu(III) extraction and refining on a pilot plant scale.

Green Synthesis of Silver Nanoparticles using Ajuga parviflora Benth and Digera muricata Leaf extract: Their Characterization and Antimicrobial Activity

The aim of the present study is to search out nontoxic silver nanoparticles synthesized from the leaf extract of two plants Ajuga parviflora Benth and Digera muricata for antimicrobial activity. The plants used in this investigation are rich in alkaloids, flavonoids, steroids, terpenoids, protein, amino acids, carbohydrate, quninones, phenols and tannins. The formation of nanoparticles were confirmed by UV/Visible spectroscopy, peaks at 423nm for Ajuga parviflora Benth and 408nm for Digera muricata. The morphology of the silver nanoparticles was established through state of the art spectroscopic tools. SEM analysis reveals average size of AgNPs 18 nm for Digera muricata and 22 nm for Ajuga parviflora Benth respectively while transmission electron microscopy confirms that AgNPs are spherical in shape. The synthesized nanoparticles were subjected to Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Pseudomonas aeruginosa. The results suggest that the silver nanoparticles have promising activity against all the bacterial strains and can be used an effective bactericides.