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Öğe Experimental Investigation of Cationic Gemini Surfactants: Self-Assembly, Corrosion Inhibition, Foaming and Dye Solubilization Properties(Wiley-V C H Verlag Gmbh, 2023) Kasapoglu, Sinem; Batigoc, Cigdem; Boz, Mesut; Tetik, OvulIn this study, two cationic gemini surfactants 12-3-12 and 12-3(OH)-12 were synthesized in our labrotory. The critical micelle concentration (CMC) values of synthesized surfactants were determined by conductivity measurements. The aggregation number (Nagg) of micelles was calculated using the pyrene probe fluorescence method. It was been investigated the corrosion effect of cationic gemini surfactants were denoted as 12-3-12 and 12-3(OH)-12 for carbon steel in 1 M HCl. The inhibition effect was investigated using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and scanning electron microscopy (SEM) techniques. It has been determined that both surfactants showed the best inhibitory effect at low concentrations. The foaming capacity (FC) and the foam stability (FS) of gemini surfactants were studied by measuring the foam volume for 0.5 % (w/v) surfactant solutions and it was observed that the foaming properties of 12-3(OH)-12 gemini surfactant were better. The solubility capability of both surfactants was tested with the water-insoluble dye Sudan Red B and it was observed that the solubility increased significantly over the CMC value of the cationic gemini surfactants. Finally, the corrosion effect, foam capacity and foam stability and effects on paint solubility of the synthesized surfactants were obtained at very low concentrations.Öğe Micellization behaviour and thermodynamic parameters of 12-2-12 gemini surfactant in (water plus organic solvent) mixtures(Academic Press Ltd- Elsevier Science Ltd, 2011) Batigoc, Cigdem; Akbas, Halide; Boz, MesutThe effect of organic solvents on micellization behaviour and thermodynamic parameters of a cationic gemini (dimeric) surfactant, C12H25(CH3)(2)N+-(CH2)(2)-N+(CH3)(2)C12H25 center dot 2Br(-), (12-2-12) was studied in aqueous solutions over the range of T = (293.15 to 323.15) K using the conductometric technique. Ethylene glycol (EG), dimethylsulfoxide (DMSO) and 1,4-dioxan (DO) were used as organic solvents with three different contents. The critical micelle concentration (cmc) and the degree of counter ion dissociation (a) of micelles in the water and in the (water + organic solvent) mixtures including 10%, 20%, and 30% solvent contents were determined. The standard Gibbs free energy (Delta G degrees(m)), enthalpy (Delta H degrees(m)) and entropy (Delta S degrees(m)) of micellization were estimated from the temperature dependence of the cmc values. It was observed that the critical micelle concentration of the gemini surfactant and the degree of counter ion dissociation of the micelle increased as the volume percentage of organic solvent, and temperature increased. The standard Gibbs free energy of micellization was found to be less negative with the increase in the organic solvent content and temperature. (C) 2011 Elsevier Ltd. All rights reserved.Öğe Spectrometric studies on the cloud points of Triton X-405(Elsevier, 2009) Akbas, Halide; Batigoc, CigdemThe effect of various chemicals on the cloud point (CP) of nonionic surfactant Triton X-405 (TX-405) in aqueous solutions has been investigated. In the measurements Of Cloud point temperatures, UV-visible spectrophotometer was used instead of visual observation. The values of CP for Triton X-405 could not be measured directly because TX-405 had an average number of oxyethylene units per molecule, p approximate to 35 and a CP > 100 degrees C. To avoid additional measurements Linder pressure, TX-405 had their CP lowered below the normal boiling point of their solutions by adding the salting-out, CP-lowering salts at various concentrations, measuring the depressed CP Values and extrapolating them to zero salt concentration. The CP values decrease linearly with increasing concentration of salts at studied concentrations. The results showed that the addition of the simple salts and nonionic surfactant Triton X-114 (TX-114) which are infinitely miscible with water decreased the cloud point of the TX-405. In this study, the real CP values of TX-405 which are merely listed as > 100 degrees C in the literature was found as 116 +/- 1 degrees C in various samples. In the lyotropic series, it is expected that the effect of F- > Cl- > Br- will be on the decrease in CP, because the ionic sizes increase along the group consequently decreasing the formal charge density on anion, thus lowering the attraction on anion and thereby lowering the attraction of water. The order of CP depression for the other anions is as follows: PO43- > SO42- > NO3- > Br-. This means that electrolyte containing trivalent anions is more effective at salting-out the PEO chain than those containing divalent anions and monovalent anions. Cations effectiveness is present in the following order for change: Na+ > K+ > NH4+ because of their effect on water structure and their hydrophilicity. Overall the electrolytes and nonelectrolytes have a large amount of effect on CP of nonionic surfactant, because of their effect on water structure and their hydrophilicity. (C) 2009 Elsevier B.V. All rights reserved.Öğe Spectrophotometric determination of cloud point of Brij 35 nonionic surfactant(Elsevier, 2011) Batigoc, Cigdem; Akbas, HalideThe cloud point of nonionic surfactant polyoxyethylene (23) lauryl ether (Brij-35) was determined in the presence of various inorganic electrolytes. The measurements of cloud point (CP) were carried out with UV-vis spectrophotometer instead of visual observation. CP of Brij-35 could not be measured directly because its CP is more than 100 degrees C. Therefore, CP values of Brij-35 were lowered by the addition of electrolytes. In this study, NaF, NaCl, NaBr, KNO3, K2CO3, K-3 PO4, Li2SO4, Na2SO4, K2SO4,(NH4)(2)SO4, CuSO4, ZnSO4, CoSO4 were used as electrolytes. Linear lines which were drawn with CP values were extrapolated to zero electrolyte concentration. The real CP value of Brij-35 which is merely listed as > 100 degrees C in the literature was found as 118.5 +/- 0.5 degrees C for all samples. Furthermore, the effects of the nature of the cation and the anion and the valencies of the cations on CP were reported and the rate of decrease in CP with concentration is discussed. (C) 2011 Elsevier B.V. All rights reserved.Öğe Study on cloud points of Triton X-100-cationic gemini surfactants mixtures: A spectroscopic approach(Pergamon-Elsevier Science Ltd, 2010) Akbas, Halide; Boz, Mesut; Batigoc, CigdemThis study investigates the effects of various cationic surfactants on the cloud point (CP) of the nonionic surfactant Triton X-100 (TX-100) in aqueous solutions. Instead of visual observation, a spectrophotometer was used for measurement of the cloud point temperatures. The values of CPs for Triton X-100 can be measured directly because TX-100 has an average number of oxyethylene units per molecule of p approximate to 9.5 and a CP = 66.0 degrees C. Quaternary ammonium dimeric surfactants (m-s-m, m = 10, 12, and 16, and s = 2, 6, and 10) were synthesized and used. The melting temperature T-M and the Krafft temperature T-K were measured for 1 wt% aqueous solutions of these synthesized surfactants. The melting temperature of the solid gemini surfactants increased with the carbon number of the alkyl chain. The results showed that additions of the gemini surfactants (which are infinitely miscible with water) to Triton X-100 increased the cloud point of the TX-100 solutions. All salts tested in these studies had a large effect on the CPs of nonionic surfactants due to their effect on water structure and their hydrophilicity. The effect of the alkyl chain length of the gemini surfactant on the CP of Triton X-100 is therefore more important than the spacer chain length. (C) 2009 Elsevier B.V. All rights reserved.Öğe Thermodynamic parameters of clouding phenomenon in nonionic surfactants: The effect of the electrolytes(Elsevier Science Bv, 2017) Batigoc, Cigdem; Akbas, HalideIn this study, the thermodynamics of the cloud point (CP) of the two non-ionic surfactants, polyoxyethylene (40) iso octylphenyl ether, (TX-405) and polyoxyethylene (23) lauryl ether, Brij-35 were investigated in different electrolyte concentrations. In the measurements of cloud point temperatures, UV-visible spectrophotometer was used instead of visual observation. Li2SO4, Na2SO4, KNO3, K2SO4, K3PO4 and (NH4)(2)SO4 were used as electrolytes. Thermodynamic parameters were calculated from cloud point values of nonionic surfactant-electrolyte mixtures. The CP values in the presence of KNO3 were obtained by an extrapolation of the straight line. The results of the energetics of clouding showed that the standard Gibbs free energy (triangle G(cp)(o)) was positive but the enthalpy (triangle H-cp(o)) and the entropy (triangle S-cp(o)) were negative in all cases. Furthermore, the enthalpy-entropy compensation relationship was estimated and the compensation temperature values (Tc) values were found as 389.70 K and 391.19 K for TX-405 and Brij-35, respectively. (C) 2017 Published by Elsevier B.V.Öğe Thermodynamic Study of the Interaction Between CI Reactive Red180 with Cationic Gemini Surfactant in Aqueous Solution(Asian Journal Of Chemistry, 2012) Akbas, Halide; Elemenli, Aylin; Batigoc, Cigdem; Boz, MesutInteractions between Reactive Red 180 and cationic gemini surfactant solutions were investigated by means of electrical conductivity measurement:, at different temperatures ranging from 298.15 to 323.15 K. Gemini surfactant of the type N,N'-didecyl-N,N,N',N'-tetramethyl-N,N'-ethanediyl-diammonium dibromide referred as (10-2-10) was synthesized in our laboratory. It was observed that a decrease in the measured specific conductance of dye-gemini surfactant mixtures was caused by the formation of nonconducting or less conducting dye-surfactant associates. The aggregation of surfactant and dye takes place at a surfactant concentration far below the critical micelle concentration of the individual surfactant. The long-range electrostatic forces and short-range hydrophobic interactions are very important factors at the dye-surfactant aggregation in aqueous solutions. From conductivity data for dyes-gemini surfactant interaction such as micellar ionization degree, counterion binding, equilibrium constant and thermodynamic parameters of interaction were calculated. Thermodynamic parameters of interaction indicate that interaction of dye-(10-2-10) is enthalpy driven.Öğe Thermodynamics of non-ionic surfactant Triton X-100-cationic surfactants mixtures at the cloud point(Academic Press Ltd- Elsevier Science Ltd, 2011) Batigoc, Cigdem; Akbas, Halide; Boz, MesutThis study investigates the effects of gemini and conventional cationic surfactants on the cloud point (CP) of the non-ionic surfactant Triton X-100 (TX-100) in aqueous solutions. Instead of visual observation, a spectrophotometer was used for measurement of the cloud point temperatures. The thermodynamic parameters of these mixtures were calculated at different cationic surfactant concentrations. The gemini surfactants of the alkanediyl-alpha-omega-bis (alkyldimethylammonium) dibromide type, on the one hand, with different alkyl groups containing m carbon atoms and an ethanediyl spacer, referred to as m-2-m (m = 10, 12, and 16) and, on the other hand, with -C-16 alkyl groups and different spacers containing s carbon atoms, referred to as 16-s-16 (s = 6 and 10) were synthesized, purified and characterized. Additions of the cationic surfactants to the TX-100 solution increased the cloud point temperature of the TX-100 solution. It was accepted that the solubility of non-ionic surfactant containing polyoxyethylene (POE) hydrophilic chain was a maximum at the cloud point so that the thermodynamic parameters were calculated at this temperature. The results showed that the standard Gibbs free energy (Delta G(cp)(o)), the enthalpy (Delta H-cp(o)) and the entropy (Delta S-cp(o)) of the clouding phenomenon were found positive in all cases. The standard free energy (Delta G(cp)(o)) increased with increasing hydrophobic alkyl chain for both gemini and conventional cationic surfactants; however, it decreased with increasing surfactant concentration. (C) 2011 Elsevier Ltd. All rights reserved.
