Effect of copolymer structure on micellar behavior of acrylamide-octylphenylpoly (oxyethylene) acrylate surfactant

Acrylamide-octylphenylpoly (oxyethylene) acrylate copolymer (AM-C8PhEOnAc) surfactant is the copolymer of acrylamide (AM) and octylphenylpoly (oxyethy lene) acrylate macromonomer (C8PhEOnAc). The effect of the copolymer struct ure on the micellar behavior in aqueous solution was studied using dynamic light scattering. It has been found that the length of ethylene oxide (EO) in the branch and the content of C8PhEOnAc in the copolymer surfactant have great effects on the size and distribution of the micelles. For AM-C8PhEO7 Ac copolymer, at the concentration of 5 x 10(-4) g/ml, the micellar size in creases with the increase of C8PhEO7Ac content. However, for AM-C8PhEO10Ac copolymer, the result is the opposite; the micellar size decreases with the increase of C8PhEO10Ac content. Larger C8PhEOnAc content leads to narrower micellar distribution. For copolymer surfactants with equal C8PhEOnAc cont ent, when the concentration of copolymer solution is the same, the copolyme r with longer EO length forms smaller micelles.