A Structure of the Surfactant

In general, the CMC in aqueous media decreases as the hydrophobic character of the surfactant increases. 

The introduction of a polar group such as O— or —OH into the hydrophobic chain generally causes a significant increase in the CMC in aqueous medium at 

TABLE 3-2 Critical Micelle Concentrations of Some Surfactants in Aqueous Media 

Branched C12H25S04 Na+ Branched C12H25S04 Na+ Ci2H25S04-Na+ Ci2H25S04-Na+ Ci2H25S04-Na+ 

H20-carbon tetrachloride H20-benzene 0.1 MNaCl (aq.)-heptane 0.1 MNaCl (aq.)-ethylenzene 0.1 MNaCl (aq.)-ethylacetate 

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