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Öğe Diffusion and Selective Transport of Alkali Cations in a Polysulfone Ion-exchange Membrane(GAUTHIER-VILLARS, 1995) Ersöz, M.; Lale, M.; Atalay, T.he diffusion of alkali metals through a charged polysulfonated ICE-450 ion exchange membrane has been measured as a function of pH and conservation of the external solution at 25 degrees C. The permeability and diffusion coefficients were found to increase in the sequence Cs(+)greater than or equal to K+>Na+>Li+ and with the external concentration. This sequence can be explained by considering the hydration of the ions in the membrane. The modes of membrane/solution distribution and the diffusion of cations as a controlling factor in the membrane permselectivity and hydration values of cations both correlated consistently with the flux data, as well as with the estimated membrane permselectivity parameters. The selective transport of K/Na and K/Li binary systems at various pH gradients through the membrane was also investigated under various conditions. The selectivity depended on both the hydrated ionic size and the interaction between the fixed groups in the membrane and the metal ions. A good agreement was found between the observed diffusion coefficients and the selectivity values and the limiting mobility ratio in water.Öğe The Effect of Ph and Temperature on the Sorption of Zinc(Ii), Cadmium(Ii), and Aluminum(Iii) Onto New Metal-Ligand Complexes of Sporopollenin(ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS, 1995) Pehlivan, E.; Ersöz, M.; Pehlivan, M.; Yıldız, S.; Duncan, H. J.Sorption of metal ions from aqueous solution onto metal-ligand complexes of sporopollenin derivatives has been measured as a function of pH at several temperatures between 20 and 50 degrees C, Novel metal-ligand exchange resins possessing oxime and carboxylic acid sidearm functionality were prepared through the reaction of diaminosporopollenin with dichloro-antiglyoxime and bromoacetic acid, The pH dependencies and sorption isotherms of various metal ions such as Zn(II), Cd(II), and AI(III) on the resin were investigated from aqueous solution, The sorption behavior of these metal-ligand complexes of sporopollenin derivatives and the possibilities of selectively removing and recovering heavy metals are explained on the basis of their chemical nature and complex properties and the results are interpreted in terms of the variations of pH. (C) 1995 Academic Press, Inc.Öğe Effects of the Functional Groups of Polystyrene on Its Adhesion Improvement and Corrosion Resistance(VSP BV, 1998) Kurbanova, R.; Okudan, A.; Mirzaoğlu, R.; Kurbanov, S.; Karataş, İ.; Ersöz, M.; Özcan, E.; Ahmedova, G.; Pamuk, V.Novel functionalized polystyrenes having groups such as epichlorohydrin, epoxy, acetyl, C=C double bond, and carboxyl were synthesized by the reaction of polystyrene with epichlorohydrin, unsaturated hydrocarbons, and organic anhydrides in the presence of Lewis acid catalysts. The adhesion capability and corrosion resistance of the new synthesized functionalized polystyrenes to metals under various conditions were investigated. A very good relationship was observed between the quantity of functional groups bonded to the aromatic rings of the polystyrenes and the adhesion and corrosion resistance properties of the polyfunctionalized polystyrenes. It was also observed that the new polyfunctionalized polystyrenes obtained by chemical modification with maleic anhydride, acetic anhydride, isoprene, butadiene, and epichlorohydrin in the presence of cationic catalysts resulted in high adhesion and anti-corrosion properties.Öğe Estimation of Diffusion Coefficients in Biomembranes(Academic Press Inc, 2000) Ersöz, M.In this paper, the determination of diffusion coefficients in plant biomembranes for the nonstationary diffusion state is discussed. If is suggested that any point in the heterogeneous structures may be considered to be in Donnan equilibrium with a given external salt concentration. For this purpose, the non-stationary-state nonlinear differential equation for the salt concentration profile is solved numerically, which could be used to determine the diffusion coefficients of biomembranes from experimental concentration values in the receiver phase as a function of time. Quantitative relations were obtained which describe the time-dependent concentration changes of a membrane system with equilibrium distribution.Öğe Ion-Exchange Equilibria of Heavy-metals in Aqueous-solution on New Chelating Resins of Sporopollenin(ELSEVIER SCIENCE BV, 1995) Ersöz, M.; Pehlivan, E.; Duncan, H.J.; Yıldız, S.; Pehlivan, M.Studies have been conducted on the sorption of several heavy metal ions Cu(II), Ni(II), Zn(II), Cd(II) and AI(III) from aqueous solutions on the new chelating exchangers of sporopollenin (Lycopodium clavatum) as a function of pH at several temperatures between 20 and 50 degrees C. The novel metal-ligand exchange resins possessing oxime and carboxylic acid side arm functionality were prepared through the reaction of diaminosporopollenin with dichloroantiglyoxime and bromoacetic acid. The sorption of all metals increased considerably in the range of pH 6-10 and was observed in sequence as: Cu greater than or equal to Ni > Zn > Cd > Al for carboxylated-diaminoethyl-sporopollenin (DAEC) and Ni greater than or equal to Cu > Zn > Cd > Al for bis-diaminoethyl-glyoxime-sporopollenin (bDAEG). The level of pH of the aqueous medium had a large influence on the sorption capacity, and the uptake of metals, except Al(III), was found to be 90% or more. The metal-form resins afforded complete recovery of the sorbed species by acid stripping. Both resins also showed high stability towards concentrated acids and bases and retained their high capacity for heavy metals.Öğe Ion-exchange Selectivities of Amino-acids for the Ammonium Ion on Periderm and Cuticular Membranes(MARCEL DEKKER INC, 1995) Ersöz, M.; Duncan, H.J.The selectivity coefficients of some neutral amino acids for the ammonium form of potato periderm and pear fruit cuticular membranes were determined, using the mass action law, and were found to be correlated with various physicochemical parameters. Relationships were obtained between selectivity coefficients and physicochemical parameters such as the partial molar volume and molecular weight. The results show that the selectivity coefficient value increases with an increase in molecular size and partial volume of the amino acids through extension of the hydrophobic-CH2-group.Öğe Kinetic Study of Ligand Exchange Reaction of Anions as Ligands on DAE-sporopollenin(ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS, 1996) Ersöz, M.; Vural, U. S.; Yiğitoğlu, M.; Sezgin, M.The specific rate coefficients and ligand sorption isotherms of Br and I- as ligands on diaminoethyl-sporopollenin were determined as a function of pH and temperature between 20 and 60 degrees C. The ligand exchange rates were measured just after the rapid mixing of the ligand solution with the resin suspension. The data have also been analyzed to obtain activation parameters Delta G, Delta H, and Delta S for reaction in the corresponding mixture. A single ligand-exchange process was observed; the sorption of ligand increased with decreasing pH and hydrated radius of ligands and increasing temperature. A reaction mechanism which describe the ligand exchange reaction is proposed.Öğe Ligand Sorption Kinetics of Aromatic-amines on New Ligand-exchanger Sporopollenin in Cobalt Ion Form(JOHN WILEY & SONS INC, 1995) Vural, U.S.; Ersöz, M.; Pehlivan, E.An approach to study of intraparticle ion-exchange kinetics of aromatic amines such as p-chloroaniline, p-toluidine, and p-nitroaniline as ligands on Co2+ loaded-ligand exchanger of sporopollenin (carboxylated epichlorohydrine [CEP]-sporopollenin) is presented and the ligand-exchange reaction in the resin matrix is shown to be rate-determining, Kinetic studies of aromatic amines as ligands on the CEP-sporopollenin have been performed using continuous column runs. The observed rate seems to be related to the rate of ligand sorption with the mobile phase (ion) and pH in the aqueous phase. The rate of attainment of equilibrium sorption and breakthrough curves of aromatic amines is seen to be nearly similar. With the sorption mechanism deduced to be dominantly particle diffusion-controlled diffusion coefficients determined were found to range from 1.10(-8) to 1.0 10(-9) cm(2) s(-1). Coupled with the fact that different concentrations of solution were employed, these results may be interpreted as indicating that particle diffusion is the rate-determining step; on the contrary, film diffusion was not a rate-controlling step in the ligand-sorption process under the conditions employed. (C) 1995 John Wiley & Sons, Inc.Öğe Ligand-exchange Chromatography of Nucleosides, Nucleic-Acid Bases and Amines on Copper(Ii) Glyoximated-Lycopodium Clavatum With Refractive-İndex Detection(MARCEL DEKKER INC, 1989) Ersöz, M.; Pehlivan, E.; Yıldız, S.Ligand-exchange separation of nucleosides, nucleic acid bases and amines has been studied by using a new exchanger ob- tained by functionalyzing Lycopodium Clavatum with glyoxime. This study shows that ligand-exchange chromatography with glyoximated-lycopodium clavatum can provide new opportunities for the rapid separation of ligands.Öğe Permeability of Periderm and Cuticular Membranes to Alkali Cations(Academic Press Inc Jnl-Comp Subscriptions, 1995) Ersöz, M.; Duncan, H. J.The rates of penetration of alkali cations through isolated potato periderm and pear fruit cuticular membranes as a function of pH and the external solution concentration were determined. Steady-state rates were measured using a diaphragm diffusion cell, and permeabilities and the corresponding diffusion coefficients were calculated from the lag time. The observed penetration rates of the alkali cations in the periderm and cuticular membranes were in the order Cs+ > K+ > Na+ > Li+. This is the order of increasing crystal radii and the order of decreasing exchange selectivity. The diffusion coefficients of all counterions increased as the external concentration was increased. (C) 1995 Academic Press, Inc.Öğe Recovery and Concentration of Al(III), Fe(III), Ti(IV), and Na(I) From Red Mud(Academic Press Inc., 2001) Çengeloğlu, Y.; Kır, E.; Ersöz, M.The transport of Al(III), Fe(III), Ti(IV), and Na(I) ions through charged polysulfonated membrane under Donnan dialysis conditions has been studied as a function of HCI concentration at room temperature. In this process, the membrane is separated by two electrolyte solutions: one side (donor phase) is initially red mud aqueous solution containing Al(III), Fe(III), Ti(IV), and Na(I) ions and the other side is HCI solution at different concentrations with no external potential field applied. The transport of metal ions through membranes was correlated with the flux data, as well as with estimated diffusion coefficients. It was observed that the transport of metals is influenced by the HCI concentration and the flux of ions increased with H+ ion concentration in the receiver phase.Öğe Selectivity and Kinetics of Ligand Exchange of Anions in A Chelate Ion Exchanger(GAUTHIER-VILLARS, 1997) Ersöz, M.; Cengeloğlu, Y.; Gökdemir, N.; Lale, M.Ligand selectivity plots and interdiffusion coefficients are presented for the chloride form of a ligand exchanger chemically derived from sporopollenin. Exchanges of iodide and bromide for chloride as the ligand were determined and found to increase with decreasing pH and ion hydration number, The ligand-exchange rates were measured as a function of pH just after rapid mixing of the ligand solution with the resin suspension at temperatures between 20 and 60 degrees C. The results are interpreted in terms of structure, the diffusivity of the ligands, the rate constant for chelate complex formation, and the hydrated radius of the ligands.Öğe Sorption of Target Anions by Ligand Exchange(JOHN WILEY & SONS INC, 1998) Çengeloğlu, Y.; Mercimek, B.; Kara, H.; Ersöz, M.The sorption of anionic ligands such as I-, Br-, and SCN- onto diaminoethyl-sporopollenin (DAE-Sporopollenin) was investigated in both column and batch experiments at room temperature. The isotherm binding constants suggest that the resin is most efficient at the binding of I- compared with Br- or SCN-. The general ligand sorption affinity series observed was I- > Br- > SCN-. This ligand sorption could be described by considering the hydration of ions in the exchanger. The sorption behavior of the ligand exchanger and the possibilities of selectively removing and recovering ligands are discussed on the basis of their chemical and complexing properties.Öğe The Study of Kinetic Models for Ligand Exchange of Anions as Ligands Using Ligand-Exchange Resin(JOHN WILEY & SONS INC, 1997) Ersöz, M.; Yiğitoğlu, M.; Ayar, A.A comparative study of kinetic models for ligand exchange of I- --> Cl- and Br- --> Cl- as ligands as a function of pH and concentration using diaminoethyl-sporopollenin (DAE-sporopollenin) resin were investigated during the ligand-exchange reaction of the liquid phase. A batch technique was employed for the study of the kinetics of I and Br/Cl exchange as ligands. Five kinetic models were applied to the experimental data. The rate of ligand exchange was increased with decreasing of the hydrated ionic radius and pH. The curve fitting of the mathematical models and the behavior of the kinetic curves are discussed for direct ligand exchange under the conditions employed.Öğe Transport Studies of Iodine Through Liquid Membrane System(JOHN WILEY & SONS INC, 1996) Vural, U. S.; Ersöz, M.Transport of iodine by a charge-transfer mechanism through a bulk organic liquid membrane system containing calixarene based on donor-type carriers was studied. It was found that the transport of iodine is facilitated by n-donor carriers depending on the pH of the source phase. The color of iodine solutions on the source side turned from brown to colorless. The passage of iodine through the organic bulk liquid membrane was governed by donor-acceptor interaction between n-donor atoms in the carrier and sigma-acceptor (iodine atoms) and by the diffusion of an n-sigma-type charge-transfer complex in the membrane followed to release by the Lewis acid-base interaction in the aqueous phase. The transport by the new carrier arises both from the different extraction equilibrium constants between the aqueous phase and donor-acceptor interaction with iodine and the carrier in the organic phase.
