Solution and rheological properties of cationic cellulose/gemini surfactant: Effect of the alkyl chain and spacer length.

In this paper, three sulfonate-containing gemini surfactants, sodium 1,1-(4,4-methylenebis(4,1-phenylene))bis(1-oxooctane-2-sulfonate) (C-M-C), sodium 1,1-(4,4-(ethane-1,2-diyl)bis(4,1-phenylene))bis(1-oxooctane-2-sulfonate) (C-M-C), sodium 1,1-(4,4-methylenebis(4,1-phenylene))-bis(1-oxododecane-2-sulfonate) (C-M-C), were synthesized and characterized with FT-IR, H NMR and MS. Furthermore, interaction between a cationic cellulose-based polyelectrolyte, PQ-10, and gemini surfactants were investigated by surface tension, turbidity, flow and low-amplitude oscillation rheology analysis. For comparing, the interaction of their corresponding monomeric counterpart sodium dodecyl sulfate (SDS), sodium 1-octanesulfate (SOS) was also studied. Results showed that the concentration value at T, defined as critical surface complex concentration, for the PQ-10/surfactant was in order of PQ-10/C-M-C> PQ-10/C-M-C > PQ-10/C-M-C. Precipitation appeared at low concentration for Gemini surfactants than their monomeric counterparts, and for the gemini surfactants with shorter spacer or longer hydrocarbon chain. The increase/decrease of the crossover frequency (ω) (the relaxation time, τ) for PQ-10/C-M-C indicated the formation/collapse of network structures, while PQ-10/SDS showed no obvious change.