Interactions between Copper Dodecylsulfate Micelles and Hydroxyethyl or Hydroxypropyl Cellulose in Water at 25°C

Abstract

The interaction of copper dodecylsulfate [(Cu(DS) 2] with hydroxyethylcellulose [HEC] and with hydroxypropylcellulose [HPC] has been investigated using essentially potentiometric measurements. In the case of HEC, no change is observed either of the CMC or of the degree of counterion condensation of the anionic micelles upon addition of up to 1 weight percent of polymer, indicating negligible interaction between that polymer and the anionic surfactant. In the presence of HPC, bound and free Cu(DS) 2 micelles were detected. The variation of CMC and of the counterion degree of condensation of both bound and free micelles resemble closely those displayed by the same surfactant with poly(vinylpyrrolidone). Also, based on the present observations, HEC is more hydrophilic than poly(ethylene oxide). Cloud point and Krafft point measurements confirm the above interpretation concerning the interaction between the surfactant and both polymers.