DETERMINATION OF THE CRITICAL MICELLE CONCENTRATION OF NEUTRAL SURFACTANTS BY MEANS OF A COATED WIRE ION-SELECTIVE ELECTRODE

The critical micelle concentrations (CMC) of three neutral surfactants, Triton X-100, Triton X-165, and Triton X-305, were determined using wire electrodes coated with tetraheptylammonium chloride (THAC) or benzalkonium chloride (BAC) and a constant concentration of the appropriate chloride. The values determined with the THAC electrodes and 10(-4.4) M THAC solutions are in agreement with previously reported values. When 10(-5.0) M THAC, or 10(-4.0) or 10(-5) M BAC was used, the measured CMC values were lower than expected.