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    Derivatization of Esters of p-Tert-Butylcalix[6]arene with some Snsymmetrical Vic-Dioxime Compounds
    (Marcel Dekker Inc, New York, NY, United States, 1994) Vural, Ufuk S.; Sevindir, H. Cahit
    The oximated derivatives of the p-tert-butylcalix[6]arene which are obtained by the esterification of the calixarene on the lower rim, and their interaction with some unsymmetrical vic-dioximes. The tetraester of the calixarene isolated by the reaction of calixarene with p-nitrobenzoyl chloride in high yield. The nitro groups of tetraester compound reduced to tetraamino groups by SnCl2.2H2O and, the oximated derivative obtained by the macrocyclic compound treatment with monochloroglyoxime, phenylchloroglyoxime and, p-tolylchloroglyoxime which are unsymmetrical vic-dioximes. Thus, the complexation ability of this new macrocyclic compounds by some transition metals increased according to the unsubstituted tetraester of p-tert-butylcalix[6]arene.
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    Ligand-Exchange Chromatography of Aromatic Amines on Resin-Bound Cobalt lon
    (Marcel Dekker Inc, 1996) Pehlivan, Erol; Vural, Ufuk S.; Ayar, Ahmet; Yıldız, Salih
    The use of cobalt metal for the selective separation of aromatic amines is completed with a chemically bonded diamine and glyoxime functional groups onto Lycopodium clavatum, Grimes and amines are excellent complexing agents for transition metal ions. Cobalt(II) metal ions can easily be immobilized on bis-diaminoethyl-glyoximated sporopollenin (bDAEG-sporopollenin). The ligand-exchange behavior of modified Lycopodium clavatum with respect to aromatic amines was investigated. This will permit the evaluation of bDAEG-sporopollenin ligand exchangers for their utilization as sorbents in the recovery, pollution control, and elimination of amines from wastewater.
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    Sorption of Aromatic-Amines on a New Ligand Exchanger of Sporopollenin-bound Co2+ Ion
    (Marcel Dekker Inc, 1995) Ersöz, Mustafa; Vural, Ufuk S.; Yıldız, Salih
    The mechanism of ligand-exchange sorption of aromatic amines such as p-chloroaniline, p-toluidine, and p-nitroaniline as ligands on a Co2+-loaded ligand exchanger has been studied. The observed rate seems to be related to the rate of ligand sorption with the mobile phase and pH in the aqueous phase. The saturation capacity and binding constant of ligand sorption on the resin increase with increasing basicity of amines. The rate of attainment of equilibrium sorption of aromatic amines is seen to be nearly similar. Coupled with the fact that different concentrations of solution were employed, these results may be interpreted as indicating that particle diffusion is the rate-controlling step. On the contrary, film diffusion was not rate-controlling step in the ligand sorption process under the conditions employed. It is shown that the kinetic parameters measured in single component experiments provide good prediction behavior. The pH dependencies and sorption isotherms of aromatic amines on the resins were also studied.
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    Synthesis and characterization of thermally stable oligomer-metal complexes of copper(II), nickel(II), zinc(II) and cobalt(II) derived from oligo-p-nitrophenylazomethinephenol
    (CHEM SOC ETHIOPIA, 2006) Vural, Ufuk S.; Mart, Hasan; Demir, H. Okkes; Sarioez, Ozlem; Muradoglu, Vefa; Koc, M. Cihangir
    Thermally stable metal complexes based on oligomers were prepared by the reaction between oligo-p-nitrophenilazomethinephenol (ONPAP) and Cu(II), Ni(II), Zn(II) and Co(II) ions. The properties of oligomer-metal complexes were studied by elemental, FT-IR and magnetic moments analyses. The thermal stabilities of the oligomer-metal complexes were compared by thermogravimetric (TG) and differential thermal (DTA) analyses. According to TG, oligomer-metal complexes were stable against to temperature and thermooxidative decomposition. The weight losses of oligomer-metal complexes were found to be 5 and 50 % at 200 and > 850 (Cu(II)), 172 and 600 (Ni(II)), 252 and > 850 (Zn(II)) and 174 and 510 (Co(II)), degrees C, respectively. Based on half degradation temperature parameters Cu(II) and Zn(II) complexes were more resistant than the others.
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    Transport and Selectivities of Amino-Acids on Periderm and Cuticular Membranes
    (TAYLOR & FRANCIS INC, 1995) Ersöz, Mustafa; Vural, Ufuk S.; Duncan, Harry J.
    The transport of amino acids through isolated potato periderm and pear fruit cuticular membranes were investigated. The transport rate depended on the molecular size of amino acids and decreased with an increase in molecular size through extension of the hydrophobic -CH2- group. The selectivity coefficients of amino acids for the ammonium ion form of periderm and cuticular membranes were also determined, using the mass action law. They were found to be correlated with various physicochemical parameters such as the partial molar volume and the molecular weight.