Abstract
The effect of different chain length, solution pH and inorganic salt addition on the surface activity of synthesized borate surfmers in aqueous solution was investigated through the surface tension method. Much emphasis was laid on the mixing effect of the borate surfmers with cetyl or hexadecyl trimethyl ammonium bromide (CTAB). The results showed that the synthesized borate surfmers possess excellent surface activity with a minimum solution γCMC of 28.6 mN·m−1 (pH = 7, 298 K). The surface activity of the borate surfmers tended to enhance with the increase in the hydrophobic chain length and solution pH. Meanwhile, the inorganic salt addition had no obvious impact on it. The effect of chain length on the mixed system was demonstrated through regular solution theory. The synergistic interaction between borate surfmers and CTAB was studied. The chain growth favored the increase in |βm| of the mixed system, indicating a strengthening interaction of the two components.