A simple U-shaped fiber optic probes for measurement of critical micelle concentration (CMC) in surfactant solutions

In this paper a simple U-shape optical fiber probe, for critical micelle concentration measurement, using evanescent adsorption effect has been described. Fabrication and characterization of the U-shape fiber optic probe has been discussed. The U-shaped is used to increase the evanescent field and hence it interaction with the sample solutions consisting mainly of sodium dodecylbenzenesulfonate. The effect of light launching condition and bending radius of the probe on the critical micelle concentration is studied. It has been shown that, for a given value of the sample solution, decrease the bending radius of the U-shape increases the sensitivity of the sensor and improve the condition for finding of critical micelle concentration point.