34 research outputs found
Characterization of Zinc Nanoferrite Doped HPMC Polymers Using X-Ray Diffraction
HPMC Polymer composites were prepared by doping various concentrations of Zinc ferrite nanoparticles using solution casting method. These polymer composites were characterized using X-Ray Diffraction and conductivity measurements. The addition of nanoferrites in the polymer matrix do change the structural and the AC conductivity properties of the film, which is supported by the results obtained and they are discussed briefly in this paper
Effective of Different Flocculants on Fresh and Stale Sugarcane Juice Clarification
Abstract The sugarcane deterioration will be start in the field after harvesting, factory storage pile, or during factory milling processes, that it has become a subject of major concern in recent years. The present work aims at to study the application of different synthesized and commercial flocculants such as pol
Kinetic studies on free radical polymerization of acrylonitrile, initiated by chloramine-T/hydrogen peroxide redox system
Abstract The Kinetics of polymerization of Acrylonitrile initiated by chloramine-T/H2O2 Redox System was studied in aqueous medium in the temperature range of 35–50°C. The effects of variations such as Monomer, CAT, H2O2, temperature, and chloramine-T disappearance (−Rm) were measured. The effect of some water- miscible organic solvents and surfactants on the rate of polymerization was investigated. The polymerization process is initiated by the free radical arising from oxidation of H2O2 by chloramine-T and terminated by the mutual combination of the growing polymer radicals. Based on the kinetic results, a suitable reaction scheme is proposed and discussed for the various rates of polymerization and thermodynamic parameters were evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5877–5883, 200
Kinetics of oxidation of indole in high indole concentration range by bromamine-B in alkaline medium catalysed by Os(VIII)
The kinetics of oxidation of indole (In) in high indole concentration range by sodium N-bromobenzene sulphonamide (BAB) in alkaline medium in presence of OsO4 catalyst have been investigated at 30 degreesC The reaction rate shows a first order dependence of rate on BAB](0) and Indole], and inverse first order dependence of rate on OH-] and first order on OsO4]. Addition of halide ions and variation of ionic strength and dielectric constant of the medium do not have any signficant effect on the reaction rate. Thermodynamic parameters have been evaluated
Kinetics and mechanism of oxidation of methionine by chloramine-T in alkaline medium in presence of OsO4 catalyst
Kinetics and mechanism of oxidation of D-L methionine (Met) by sodium N-chlorotoluene-p-sulphanamide (CBT) in alkaline medium in presence of OsO4 catalyst have been investigated at 30 degrees C, and the results are compared to the reaction without Os(VIII) catalyst. The reaction rate shows a first order dependence each on CAT] and methionine] and inverse fractional order on OH-] and tractional order on OsO4]. Additions of halide ions and variation of ionic strength and dielectric constant of the medium do not have any significant effect on the reaction rate. Thermodynamic parameters have been evaluated
Tailoring of ternary nanocomposite films of poly(vinyl alcohol)/ AgAlO2@reduced graphene oxide: An active material for flexible supercapacitors
Poly(vinyl alcohol) (PVA)/silver aluminium oxide (AgAlO2)@reduced graphene oxide (rGO) nanocomposites (NCs) as flexible supercapacitor electrodes were fabricated via an eco-friendly and scalable solution casting approach. The crystallinity and morphological characteristics of the developed NCs were characterized by using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The thermal properties were analysed by thermal gravimetric analysis (TGA). The electrochemical performance of PVA/AgAlO2@rGO NCs as a supercapacitor electrode material was investigated by cyclic voltammetry (CV) studies. PVA/AgAlO2@rGO NCs showed wide operating potential windows (1.2 V) which can greatly enhance their capacitive behaviour. The highest specific capacitance obtained was 273.4 F g-1 in the case of 2 wt % AgAlO2@rGO loaded PVA NC as compared to pristine PVA (6.04 F g-1). These NCs exhibited superior performance with the energy density (13.8 Whkg-1) and power density (150 W kg-1) at 0.5 A g-1 respectively. PVA/AgAlO2@rGO NCs exhibited the negligible equivalent series resistance and charge transfer resistance as an indication of excellent charge propagation at the interface between an electrolyte and an electrode. The NCs showed good capacity retention of 86.18% even after 1000 cycles. The NCs comprising of AgAlO2 NPs exhibited better specific capacitance than reduced graphene oxide incorporated PVA NCs, thus constituting a new approach for fabricating supercapacitors electrodes
Oxidation of primary amines by bromamine-B catalyzed by osmium(VIII) in alkaline medium: A kinetic and mechanistic study
The kinetics of oxidation of the aliphatic primary amines, n-propylamine, n-butylamine, and isoamylamine, by N-sodio-N-bromobenznesulfonamide or bromamine-B (BAB), in the presence of osmium(VIII), has been studied in alkaline medium at 35 degrees C. In the presence of the catalyst, the experimental rate law for the oxidation of the amine substrate (S) takes the form, rate = kBAB]OsO4]OH-](x), which in the absence of the catalyst changes to the form, rate = kBAB]S]OH-](y), where x and y are less than unity. Additions of halide ions and the reduction product of BAB (benzenesulfonamide). and the variation of ionic strength of the solvent medium have no effect on the reaction rate. Activation parameters have been evaluated. The proposed mechanism assumes the formation of a complex intermediate between the active oxidant species, PhSO2NBr-, and the catalyst, OsO4, in the rate determining step This complex then interacts with the substrate amine in fast steps to yield the end products. The average value for the deprotonation constant of monobromamine-B, forming PhSO2NBr-, is evaluated for the Os(VIII) catalyzed reactions of the three amines in alkaline medium as 9.80 x 10(9) at 35 degrees C. The average Value for the same constant for the uncatalyzed reactions is 1.02 x 10(4) at 35 degrees C. (C) 1997 John Wiley & Sons, Inc
A study on refractive index, orientational order parameter and distribution function in the nematic phase of a nematogenic compound
The refractive indices (ne no) and density have been measured at various temperature in the nematic-isotropic phases of nematogenic Methoxy-41-Pentyl-41-tolane. The molecular polarizability, nematic orientational order parameter are evaluated by Neugebauer anisotropic local field model. The distribution function f(β) and hence the higher order parameter ⟨P4⟩ at different temperatures in the nematic phases have been estimated
Polymerization kinetics of acrylonitrile by oxidation: reduction system using potassium persulfate/ascorbic acid in an aqueous medium
The kinetics of acrylonitrile polymerization initiated by free radicals formed in situ in a potassium persulfate/ascorbic acid redox system was investigated in an aqueous sulfuric acid medium in the temperature range of 40-70 degrees C. The rate of polymerization and the rate of the disappearance of potassium persulfate were measured. A kinetic scheme involving the production of initiating radicals from the oxidation of ascorbic acid by potassium persulfate ions and termination exclusively by the interaction of chain radicals with persulfate ions is proposed. The effects of some water-miscible organic solvents on the rate of polymerization were investigated. The temperature dependence of the rate was studied. A possible mechanism consistent with the experimental data is proposed. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 1299-1303, 201