NOPR Collection:

Temperature dependent study of thermophysical and optical properties of binary mixtures of imidazolium based ionic liquids

2016-06-01T00:00:00Z

Title: Temperature dependent study of thermophysical and optical properties of binary mixtures of imidazolium based ionic liquids Authors: Krishna, T S; Sankar, M G; Nain, A K; Munibhadrayya, B Abstract: The experimental values of densities (ρ) and speeds of sound (u) of the binary mixtures of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF₄] with α,ω-propanediols have been used to calculate the internal pressure (π_i), free volume (V_f), excess internal pressure (_πi^E), excess free volume (V_f^E), excess free energy (_G^E), excess enthalpy (_H^E) and excess entropy (_TS^E) covering the entire composition range expressed by mole fractions of ionic liquid at temperatures (298.15, 303.15, 308.15, 313,15, 318.15 and 323.15 K). The refractive indices (n_D) of these mixtures have been measured at above-mentioned temperatures and the deviations in refractive index (Δ_фⁿ_D) have been calculated. The results have been interpreted in terms of intermolecular interactions between the component molecules in the mixture. The variations of these excess properties with composition indicate that the interactions between [Bmim][BF₄] and α,ω-propanediols in these mixtures follows the order: 1,2-propanediol > 1,3-propanediol. Page(s): 664-675

Naphthalimide based hybrid nanoparticles for selective recognition of Hg(II)

2016-06-01T00:00:00Z

Title: Naphthalimide based hybrid nanoparticles for selective recognition of Hg(II) Authors: Saini, Anu; Kaur, Navneet Abstract: 1,8-Naphthalic anhydride and cystamine dihydrochloride have been used as precursors for the synthesis of a dipodal compound (1) which has been further processed into fluorescent organic nanoparticles (N1) by re-precipitation technique. This has resulted in the formation of spherical nanoparticles which have been characterized by TEM and DLS studies. These hybrid nanomaterials composed of organic and inorganic nanoparticles have been used as a sensing platform for determination of mercury(II). The sensing phenomenon shows a ratiometric response for the selective determination with Hg²⁺ ion among other heavy metal ions with enhancement in fluorescence emission at 340 nm and decrease in emission intensity at 469 nm. Other heavy metal show no interference towards recognition of Hg²⁺ ion. Page(s): 692-697

One-step synthesis of ZnO nanowires on zinc foils and their photocatalytic properties

2016-06-01T00:00:00Z

Title: One-step synthesis of ZnO nanowires on zinc foils and their photocatalytic properties Authors: Momeni, Mohamad Mohsen Abstract: ZnO nanostructures with different morphologies have been grown on zinc foil substrate by a novel and facile hydrothermal method, without the assistance of any catalyst or template. The obtained ZnO samples are characterized by SEM, EDX, XRD, UV-visible and photoluminescence techniques. The resulting ZnO nanorod has a diameter of about 70-90 nm and the average length is estimated to be in the range of 0.5-2.0 μm. It is shown that the as-grown ZnO samples have a very good crystallinity. A comparison of the photocatalytic degradation of methyl orange with different ZnO shows that the photocatalytic properties of the ZnO nanostructures depend on the morphology of ZnO. The growth process of the ZnO nanorods is proposed based on the solid-liquid-solid mechanism. Page(s): 686-691

Phenoxazinone synthase activity of a mononuclear cobalt(III) complex

2016-06-01T00:00:00Z

Title: Phenoxazinone synthase activity of a mononuclear cobalt(III) complex Authors: Mitra, Merry; Ghosh, Rajarshi Abstract: The trivalent cobalt complex, [Co(HL)₂](OAc).H₂O (1) [H₂L = N-(2-hydroxyethyl)-3-methoxysalicylaldimine], behaves as an effective catalyst towards oxidative dehydrogenation of o-aminophenol to 2-aminophenoxazine-3-one in aerial oxygen. The reaction follows Michaelis-Menten enzymatic reaction kinetics in methanol with turnover number (K_cat) = 2.83×10⁴ h^-1. Page(s): 681-685