Deparment of Chemistry

South Africa

Deparment of Chemistry

South Africa

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Gumede T.P.,Deparment of Chemistry | Luyt A.S.,Center for Advanced MaterialsQatar University2713Doha Qatar | Zubitur M.,University of the Basque Country | Muller A.J.,Ikerbasque
Journal of Polymer Science, Part B: Polymer Physics | Year: 2016

The structure and thermal properties of linear low-density polyethylene (LLDPE)/medium soft paraffin wax blends, prepared by melt mixing, were investigated by differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS and WAXS). The blends form a single phase in the melt as determined by SAXS. Upon cooling from the melt, two crystalline phases develop for blends with more than 10 wt % wax characterized by widely different melting points. The wax acts as an effective plasticizer for LLDPE, decreasing both its crystallization and melting temperature. The higher melting point crystalline phase is formed by less branched LLDPE fractions. On the other hand, the lower melting point crystalline phase is a wax-rich phase constituted by cocrystals of extended chain wax and short linear sequences of highly branched LLDPE chains. The presence of cocrystals was evidenced by standard DSC results, successive self-nucleation and annealing (SSA) thermal fractionation and by the detection of a new SAXS signal attributed to the lamellar long period of the cocrystals. © 2016 Wiley Periodicals, Inc.


Kalaivani R.,Manonmaniam Sundaranar University | Thillai Arasu P.,Kalasalingam University | Rajendran S.,Deparment of Chemistry
International Journal of ChemTech Research | Year: 2013

The inhibition efficiency (IE) of K4[Fe(CN)6] in controlling corrosion of carbon steel in aqueous solution containing 60ppm Cl- in the presence and absence of Zn2+ has been evaluated by weight loss method. The formulation consisting of 100ppm K4[Fe(CN)6] and 50 ppm Zn2+ offers 98% inhibition efficiency to carbon steel immersed in aqueous solution containing 60ppm Cl-. A synergistic effect exists between K4[Fe(CN)6] and Zn2+. As immersion period increases, the inhibition efficiency of K4[Fe(CN)6]{box drawings light horizontal} Zn2+ system decreases.AC impedance spectra reveal that a protective film is formed on the metal surface. FTIR spectra reveal that the protective film consists of Turnbull's blue and Zn(OH)2.


Panday G.,Deparment of Chemistry | Panday G.,University of the Humanities | Kasana V.K.,University of the Humanities | Hore S.K.,University of Veterinary and Animal Sciences
Journal of Applied Pharmaceutical Science | Year: 2012

Use of different agonists and antagonists for elucidating the mechanism of aqueous extract of Vernonia cinerea (L.) Less. on duodenalsmooth muscle of female albino rat suggested the presence of an active ingredient in plant having spasmogenic response that has neurogenicmechanism on rat duodenal smooth muscle. The responses of extract were dose dependent and fully reversible on wash. The findings suggestedthat the extract responses mediate through agonistic action without blockade of any receptor enzyme. Extract possibly stimulates presynaptic cholinergic nerve endings to produce spasmodic response in rat duodenal smooth muscle.


Singh J.,Deparment of Chemistry | Ali A.,Thapar University
Research Journal of Chemistry and Environment | Year: 2012

Activated Arachis hypogea shell powder has been applied for studying kinetics, thermodynamics and breakthrough studies of Cr (VI) biosorption from synthetic and electroplating industrial effluents using batch and column processes. To optimize the conditions for the maximum biosorption in batch process, the following parameters have been varied (i) contact time, (ii) initial Cr (VI) concentration, (iii) pH and (iv) adsorbent doses. Both Freundlich and Langmuir adsorption models have been used to study the batch equilibrium data and better fitting was observed with Langmuir model with correlation coefficient of 0.99. The maximum biosorption capacity of Cr (VI) in batch process was found to be 131.57 mgg -1 at pH 2 by Langmuir isotherm. The experiments were performed to study the kinetics of the Cr (VI) biosorption and obtained data were best fitted with pseudo-second-order model. The thermodynamic parameters viz., Gibbs free energy (ΔGω), enthalpy (ΔHω) and entropy (ΔSω) changes were also calculated and the observed values supported the spontaneity of the biosorption process. Two kinetic models viz., Thomas and bed depth service time model were applied to predict the breakthrough curves at different flow rates and bed depths and the best results were obtained when Cr (VI) solution of 50 mgL -1 concentration was used in a bed depth of 20 cm with a flow rate of 2.0 mLmin -1 at 2 pH. The activated Arachis hypogea shell has also been successfully employed for the biosorption of Cr (VI) from electroplating effluents to demonstrate its industrial application.


Al-Qalaf F.A.,United Arab Emirates University | Al-Qalaf F.A.,Cairo University | Al Bassam A.A.,Deparment of Chemistry | Shoukry M.M.,Deparment of Chemistry
Journal of the Chilean Chemical Society | Year: 2013

Amino acid esters (L) react with [Pd(DHP(H2O)2] 2+ , (DHP = 1,3-diamino-2-hydroxopropane) giving mixed ligand [Pd(DHP)L]2+ The kinetics of hydrolysis of [Pd(DHP)L]2+ have been studied by pH-stat technique and rate constants were obtained. Rate acceleration observed for glycine methyl ester is high. The effect with methionine methyl ester and histidine methyl ester are much less marked, as the mixed-ligand complexes with these ligands do not involve alkoxycarbonyl donors. Possible mechanisms for these reactions are considered. Activation parameters have been determined for glycine methyl ester.


Gurnule W.B.,Deparment of Chemistry | Thakre M.B.,Rashtrasant Tukadoji Maharaj Nagpur University
Der Pharma Chemica | Year: 2011

A new terpolymer resin was synthesized from 8-Hydroxyquinoline and adipamide with formaldehyde by polycondensation method in the presence of 2M HCl as catalyst. The resin was characterized by elemental analysis and spectral methods, i.e. composition of terpolymer has been determined in the basis of their elemental analysis. The terpolymer resin has been characterized by UV- Visible, I.R. and NMR spectra. The number average molecular weight has been determined by conductometric titration in non-aqueous medium. Intrinsic viscosities of the solution of the terpolymer has been determined in dimethyl formamide. The structure of the terpolymer resin was confirmed on the basis of spectral data.

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