Instant Cyclohexene Epoxidation Over Ni-TUD-1 Under Ambient Conditions

Catalysis Letters - To avoid the aggregation problem and activity loss of nickel oxide (NiO) nanoparticles (NPs) in organic reactions, NiO NPs were incorporated into TUD-1 mesoporous material....     

Hydrothermal synthesis of ZnO/C microflowers for photocatalytic degradation of organic pollutants under visible light irradiation: kinetics,mechanism and recyclability

Journal of Materials Science: Materials in Electronics - We developed an improved hexagonal wurtzite ZnO and ZnO/C microflowers through the facile hydrothermal technique. The obtained...     

Fabrication and characterization of poly(vinyl alcohol)—Glycerol—Spinel ferrites flexible membranes

Polymer membranes of ferrites nanoparticles, glycerol, and poly(vinyl alcohol) (PVA) were fabricated using a solution casting method. Spinel ferrites nanoparticles, CuFe₂O₄ or ZnFe₂O₄, and glycerol were used as dopants to control the membranes' electrical conductivity. The morphology, composition, and interaction between PVA and the dopants were investigated byscanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differentialscanning calorimeter (DSC), and thermal gravimetric analysis (TGA). Electrical characterization of the membranes was conducted by impedance spectroscopy using frequencies between 1 and 10⁶ Hz and variable temperatures. The results revealed a negative temperature coefficient of the resistance of the membranes. Additionally, membranes with ZnFe₂O₄ nanoparticles exhibit higher electrical impedance than those with CuFe₂O₄ nanoparticles. Therefore, electrical conductivity could be controlled using a suitable dopant's composition and concentration. The membranes presented in this study exhibit semiconducting properties, thus, they have potentials to be utilized in multiple applications including the flexible organic-based device. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48821.     

Pectin grafted poly(N‐vinylpyrrolidone): Optimization and in vitro controllable theophylline drug release

The present article describes preparation, optimization, and characterization of pectin grafted polyvinylpyrrolidone hydrogels followed by controllable theophylline drug release. The gels were prepared in the presence of N,N′–methylenebisacrylamide (MBAA) crosslinker and ceric ammonium nitrate (CAN) initiator under N₂ atmosphere. Optimum conditions, in terms of percent of grafting (%G), were determined as follows: Pectin = 1.0 g, [NVP] = 2.81 mM, [MBAA] = 0.65 mM, [CAN] = 0.073 mM, polymerization temperature = 30°C and time = 4.0 hrs. Hydrogels were characterized by FTIR, TGA, DSC, XRD, and SEM. In vitro controllable release of theophylline model drug was studied using different N‐vinylpyrrolidone monomer to MBAA crosslinker ratio (i.e., [NVP]/[MBAA] ratios) and different polymerization temperatures at two pH values, namely 5.5 and 7.4. The optimum conditions for colon‐targeted vehicles that could provide the least theophylline release at pH 5.5, and the most theophylline release at pH 7.4, were as follows: [NVP]/[MBAA] = 4.33, polymerization temperature = 10°C and %G = 62.2. Such promising hydrogel characteristics may play the key role in many future drug release implementations. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Biocatalytically Triggered Co‐Assembly of Two‐Component Core/Shell Nanofibers

For the development of applications and novel uses for peptide nanostructures, robust routes for their surface functionalization, that ideally do not interfere with their self‐assembly properties, are required. Many existing methods rely on covalent functionalization, where building blocks are appended with functional groups, either pre‐ or post‐assembly. A facile supramolecular approach is demonstrated for the formation of functionalized nanofibers by combining the advantages of biocatalytic self‐assembly and surfactant/gelator co‐assembly. This is achieved by enzymatically triggered reconfiguration of free flowing micellar aggregates of pre‐gelators and functional surfactants to form nanofibers that incorporate and display the surfactants’ functionality at the surface. Furthermore, by varying enzyme concentration, the gel stiffness and supramolecular organization of building blocks can be varied.     

Vanadium oxide surfaces and supported vanadium oxide nanoparticles

The information obtained from the characterization of vanadium oxide single crystal surfaces is related to the study of vanadia nanoparticles supported on silica and alumina thin films, model systems for the so-called “supported monolayer vanadia catalysts”. It is found that these particles have properties similar to V₂O₃ surfaces, where the topmost V ions are involved in vanadyl groups and have a 5+ oxidation state. A vibrational spectroscopy investigation combined with DFT calculations show that the accepted interpretation of vibrational spectra from vanadia catalysts must be revised.     

Effect of terbium doping in bismuth ferrite nanoparticles for the degradation of organic pollutant under sunlight irradiation

Journal of Materials Science: Materials in Electronics - Herein, we have studied the influence of terbium (Tb) doping in bismuth ferrite (BiFeO3/BFO) nanoparticles towards its photocatalytic...