Surface tension reduction temperature effect

For both ionic and POE nonionics, as the temperature is increased, there is a decrease in both Ym and the CMC/C2o ratios. As a result, although the surface tension of the solution may be reduced to a lower value by increase in the temperature, the surface tension reduction effectiveness, IIcmc (= To — Ycmc> where y0 is the surface tension of the pure solvent at that temperature), is always reduced by increase in temperature. 

---