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Öğe CI Reactive Orange 16-dodecylpyridinium chloride interactions in electrolytic solutions(Pergamon-Elsevier Science Ltd, 2006) Akbas, Halide; Kartal, CigdemThe effect of electrolytes on the interaction between an anionic dye and a cationic surfactant was investigated spectrophotometrically in submicellar concentration range at certain temperature. The spectral change of the azo dye C.I. Reactive Orange 16 (RO16) exhibits a high sensitivity to the polarity of dye's environment. Dodecylpyridiniurn chloride (DPC) affects the electronic absorption spectra of dye solution that is dye-surfactant interaction results formation of complex and therefore a decrease in maximum absorption spectra (1.577 at 494 nm). The electrolyte cations cause an increase of the absorbance of DPC-RO16 ion-pair complex in the following order: Ca2+ > Na+ > NH4+ > K+ > Mg2+, also for electrolyte anions Br- > Cl- > SO42-. Furthermore, this order can be changeable with increasing electrolyte concentration. The increase on absorbance value with increasing electrolyte concentration is explained as charge screening. The increase or decrease on absorption spectra of RO16-DPC solution depends on concentration range of the electrolyte added. As an increase on absorbance value with increasing electrolyte concentration is explained as charge screening, a decrease in this value for higher concentration of electrolyte is attributed as the charge of micelle shape. (c) 2005 Elsevier B.V. All rights reserved.Öğe Conductometric studies of the interaction of CI Reactive Orange 16 with cationic alkyltrimethylammonium bromide surfactants(Elsevier Sci Ltd, 2007) Akbas, Halide; Kartal, CigdemThe interactions between an anionic dye, C.I. Reactive Orange 16 (RO16) and the cationic surfactants, dodecyltrimethylammonium bromide (DTAB) and hexadecyltrimethylammonium bromide (CTAB) were studied using a conductometric method. The specific conductance of dye-surfactant mixtures was measured at five different temperatures. The equilibrium constants and other thermodynamic functions for the process of dye-surfactant ion pair formation were calculated on the basis of two theoretical models. The results showed that an increase in temperature reduces the tendency for ion pair formation as equilibrium constants decrease with increasing temperature. According to results, the surfactant which contained the longer hydrophobic chain had a stronger tendency to associate with the dye and the equilibrium constants were considerably higher than those measured for the surfactant with the shorter hydrophobic chain. These results indicate that short range, non-electrostatic interactions have a significant influence on dye-surfactant ion pair formation as well as long range electrostatic forces. (c) 2005 Elsevier Ltd. All rights reserved.Öğe Spectrophotometric studies of anionic dye-cationic surfactant interactions in mixture of cationic and nonionic surfactants (vol 61, pg 961, 2005)(Pergamon-Elsevier Science Ltd, 2006) Akbas, Halide; Kartal, Cigdem[Abstract Not Available]
