TY - JOUR ID - 75786 TI - Aggregation of an anionic azo dye with conventional cationic surfactants in premicellar region: A conductometric study JO - Progress in Color, Colorants and Coatings JA - PCCC LA - en SN - 2008-2134 AU - Javadian Farzaneh, S. AU - Hooshmand, F. AU - Asadzadeh Shahir, A. AD - Department of Physical Chemistry, Tarbiat Modares University AD - Department of Physical Chemistry, Payame Noor University, Urmiah Branch Y1 - 2011 PY - 2011 VL - 4 IS - 2 SP - 121 EP - 128 KW - Congo red KW - cationic surfactant KW - Dye KW - surfactant ion pair KW - Conductometry KW - Equilibrium constant DO - 10.30509/pccc.2011.75786 N2 - The interaction of Congo Red CR with a series of Alkyltrimethylamoniumbromide CnTAB, N-hexadecylpyridinium bromide CPB and N-hexadecylpyridinium CPC were investigated using conductometry technique. It was observed that the formation of dye-surfactant ion pairs takes place at surfactant concentration far below the critical micelle concentration of the individual surfactants. Aggregation was reflected by the appearance of a break point at conductometry plots. The equilibrium constant and other thermodynamic parameters for the ion pair formation were calculated on the basis of a theoretical model using the data obtained by conductometry. The reaction between dye and surfactants was revealed to be an enthalpy-driven reaction which is highly dependent on temperature and the structures of both dye and surfactant. UR - https://pccc.icrc.ac.ir/article_75786.html L1 - https://pccc.icrc.ac.ir/article_75786_a57bfd698091ab7076d1da5517ee53dc.pdf ER -