Search

Castor oil (CAO)/poly (N-vinyl-2-pyrrolidone) (PVP) hybrid was synthesized at different reaction conditions including PVP/CAO weight ratio, temperature, and time. The results indicated that the optimum conditions to synthesis that hybrid is reacting of PVP having a molecular weight of 40,000 Da with CAO at a weight ratio of 30% and temperature of 150°C for 60 min. The synthesized hybrid was characterized via FTIR. Emulsification of such hybrid in water results in a white stable emulsion. The TEM analysis proved that the prepared emulsion of a particle size ranges from 320 to 370 nm. The technical feasibility to apply the produced emulsion for functional finishing of cotton fabric was studied. The results obtained indicated that treating cotton fabric with easy care finishing bath containing the synthesized emulsion results in enhancement in nitrogen content, tensile strength, whiteness index, stiffness, and antibacterial activities along with a decreasing in resiliency, wettability, and surface roughness properties of treated fabric, compared to the control sample. Moreover, incorporation of zinc oxide nano-particles (ZnO-NPs) or dihydroxybenzophenone (DHBP) in the above mentioned finishing bath enhances the functional properties of the finished fabric. Furthermore, dyeing fabric samples with different reactive and direct dyes followed by finishing using the aforementioned finishing bath, in absence of ZnO-NPs and DHBP, gives rise to an enhancement in the color strength of such samples compared to the dyed samples. The fastness to washing and perspiration of only the direct dye dyed/finished sample was improved. Almost all the dyed/ finished samples exhibited an improvement in their fastness to the wet rubbing and alkaline perspiration along with a reduction in fastness to light. In addition, the SEM, as well as EDX analysis of treated fabric, was investigated. [ABSTRACT FROM AUTHOR]

This paper is devoted to preparation of gold-copper bimetallic nanoparticles deposited on inorganic supporters followed by their use in hydrogen peroxide decomposition and oxidation of ethylbenzene. The bimetallic nanoparticles of Au-Cu at molar ratio of 1:1 were synthesized by hydrothermal method in the presence of stabilizing agent-poly (N-vinyl-2-pyrrolidone) and reducing agent-glycine. The bimetallic nanoparticles were characterized by UV-Vis spectroscopy, DLS, and TEM techniques. The catalytic activity of Au-Cu bimetallic nanoparticles was evaluated with respect to decomposition of hydrogen peroxide and oxidation of ethylbenzene. [ABSTRACT FROM AUTHOR]

Abstract: To enhance the functional properties of viscose fabrics, Tinosan® CEL (TC), Ag, and TiO2 nano-particles were incorporated as functional additives in different easy care finishing formulations alone and in admixtures. Results indicated that padding viscose fabrics in finishing bath containing 10g/l TC and 60g/l dimethyloldihydroxyethylene urea (DMDHEU) enhances some performance as well as antibacterial properties of the treated fabrics. Moreover, incorporation of Ag or TiO2 nano-particles in the DMDHEU or DMDHEU/TC finishing baths enhances the functional properties of the treated samples such as antibacterial properties, UV-blocking properties, and/or self cleaning performance. Incorporation of poly (N-vinyl-2-pyrrolidone) in the aforementioned finishing formulations enhances these functional properties along with durability to wash. On the other hand, incorporation of Silicon®-SLH softener in finishing baths along with TC affects the performance and antibacterial properties of the treated fabrics. [Copyright &y& Elsevier]

Poly(N-vinyl-2-pyrrolidone)/(acrylic acid-co-styrene) [PVP/(AAc-co-Sty)] hydrogels were prepared by γ-irradiation to design as adsorptive systems. The adsorption of agricultural pesticides Fluometuron (FH), Thiophanate Methyl (TF) and Trifluralin (TI) on radiation-induced graft copolymeric adsorbents has been studied. The prepared hydrogels were characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), and the thermal properties were studied by using thermal gravimetric analysis (TGA) and Differential scanning calorimetry (DSC). The ionic character of the prepared hydrogel was improved by treatment with alkaline (NaOH), sulfonation (Sf) and alkaline/sulfonation (NaOH/Sf). The swelling as a function of PVP concentration, AAc/Sty composition, irradiation dose, temperature and pH were studies. The adsorption of pesticides on the hydrogel matrix under different conditions was studied to determine which factors have the most affect and control the adsorption capacity of hydrogel. AAc/Sty composition, type of pesticide, temperature, concentration and pH of pesticide feed solution are greatly affect the pesticide uptake. It was found that the prepared hydrogels have a great efficiency to recover the pesticides from their solutions, the maximum pesticide uptake was found to be in the sequence: TI > TF > FH. The results concluded that the alkaline/sulfonation- treated PVP/(AAc-co-Sty) hydrogels possess high efficiency for removal of pesticides. [ABSTRACT FROM PUBLISHER]

Water-dispersible Ru (0) nanorods stabilized by Poly (N-vinyl-2-pyrrolidone) (PVP) were employed as catalyst in the hydrolysis of sodium borohydride (NaBH4). The hydrogen generation rate was determined as a function of solution temperature, NaBH4 concentration, and catalyst amount. Ru (0) nanorods were found to be highly active catalysts even at room temperature. Kinetics study indicated that the hydrolysis reaction was first order in catalyst concentration and zeroth order in substrate concentration. The activation parameters of the hydrolysis reaction were also determined from the evaluation of the kinetic data. The PVP-stabilized Ru (0) nanorods provided a lower apparent activation energy (Ea = 33.4 ± 1 kJ/mol) than bulk Ru(0) metal and other reported Ru-based supported catalysts for the hydrolysis of NaBH4. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to investigate and compare the physical and functional properties of chitosan films prepared with poly (N-vinyl-2-pyrrolidone) (PVP) and polyethylene oxide (PEO). Addition of PVP or PEO reduced yellowish coloration of chitosan-based films and made the films easier to puncture and tear. Contrary to chitosan/PEO films, where addition of PEO had tendency to reduce water vapor permeability (WVP), the chitosan/PVP films with PVP content of 75% had significantly higher WVP compared to pure chitosan films. Chromium binding capacity of the films was not significantly reduced by any of the tested synthetic polymers even when they replaced up to 75% chitosan in the films. Similarly, antimicrobial efficiency was reduced only when 75% PEO or 50% PVP was used in the films. It appears that incorporation of PVP or PEO in chitosan films could significantly reduce production price with no effect on functionality of the films. [Copyright &y& Elsevier]

Abstract: Cotton fabric was thermally crosslinked with poly (N-vinyl-2-pyrrolidone) (PVP) at different conditions including temperature, time, PVP concentrations and molecular weights. Results indicated that treating the cotton fabrics with 4% aqueous solution of PVP of molecular weight 10,000 Dalton followed by drying at 85°C for 5min then curing at 160°C for 3min results in crosslinking as will as an improvement in some performance properties of that fabrics such as resiliency, tensile strength, and acid dyeability. Post-treating PVP crosslinked fabric with 5% iodine in ethanol solution for 5h at 50°C imparts antibacterial activity against Staphylococcus aureus and Escherichia coli. Moreover, incorporation of PVP in the easy-care finishing of cotton fabrics, as polymer additive, with N,N-dimethylol 4,5-dihydroxyethylene urea as a crosslinker enhances some of the performance properties of finished fabrics such as the nitrogen content, tensile strength and acid dyeability along with decreasing resiliency as well as whiteness index, whereas the ester crosslinking with citric acid, in presence of PVP, enhances resilience, tensile strength and whiteness indices accompanied with a reduction in the %N of the treated fabrics. Infra red spectrum of PVP crosslinked fabric as well as EDX analysis of loaded iodine on PVP crosslinked cotton fabric were investigated. [Copyright &y& Elsevier]