Interaction between 4-chloro-(2′-hydroxylphenylazo)rhodanine and cetyltrimethyl ammonium bromide

The interaction between 4-chloro-(2′-hydroxylphenylazo)rhodanine (ClHPAR) and cationic surfactant cetyltrimethyl ammonium bromide (CTAB) was investigated by surface tension, absorption spectra, resonance light scattering (RLS) spectra and transmission electron microscopy. It can be concluded from the experimental results that the hydrophobic forces cannot be neglected, even though the electrostatic interaction between ClHPAR and CTAB plays an important role. The RLS spectral behavior of ClHPAR changes in the presence of CTAB. The efficiency and the effectiveness of ClHPAR–CTAB mixture to decrease the surface tension of water are higher than those of any single component, i.e. CTAB and ClHPAR. As one might expect, NaCl and urine have different effects on the interaction between ClHPAR and CTAB and their interaction also depends on pH.