Study on Rheologic Properties and Molecular Configuration in the Mixed Systems of Polyacrylamide and a Gemini Surfactant

The rheological properties and the microconformations of the mixed system of hydrophobically modified polyacrylamide and a Gemini surfactant, O,O′-bis(sodium 2-lauricate)-p-benzenediol, in water, 5000 mg/L NaCl, 1.2 wt% NaOH, and 5000 mg/L NaCl with 1.2 wt% NaOH solutions were investigated, respectively. Scan electron microscopy of the samples prepared with the vacuum sublimation freezing–drying technique shows much more polymer aggregation information. The mixed system of polyacrylamide and an anionic surfactant, sodium dodecyl benzene sulfonate, was also investigated for comparison. The experimental results reveal that the rheological properties have a close relation with aggregation micostructure of the polymer. The Gemini surfactant is much more effective to affect the molecular interaction and aggregation of hydrophobically modified polyacrylamide, and thus has a higher viscosity increasing effect than the conventional surfactants.