Background: Gemini surfactants have good prospect of application development
in various fields for their superior performance in foaming, wettability, and emulsification
with lower critical micelle concentration (CMC) than conventional mono-surfactants.
Objective: The purpose of this study was to synthesize an ionic sulfonate Gemini surfactant,
which is mainly used as an oil flooding agent, to improve oil recovery and reduce oil production
Methods: With 4-dodecyl phenol, diethylene glycol and triethylene glycol as the raw materials
to synthesize two sulfonate Gemini surfactants. The single factor experiment combined
with Box-Behnken center composite experimental design, the optimum reaction conditions
were determined. The optimal reaction condition of sulfonation was determined by orthogonal
test. The product structure was characterized by nuclear magnetic resonance and infrared.
Results: The mass fraction of sodium hydroxide ω(NaOH), temperature and the quality ratio of
hexadecyl trimethyl ammonium bromide to dodecyl phenol were 18%, 93.5°C and 14.2%,
respectively. Under the condition of ice bath, the molar ratio of chlorosulfonic acid to 4, 4-
12-12 alkyl phenol polyoxyethylene ether was 2.02:1 and reaction for 5h. The critical micelle
concentration was determined to be 2×10-4, 1.05×10-4, respectively.
Conclusion: Two sulfonate Gemini surfactants, namely 5, 5-dilauryl alkyl-2,2'-(diethylene
glycol oxygen base) sodium diphenyl sulfonate and 5,5-dilauryl alkyl-2,2'-(triethylene glycol
oxygen base) sodium diphenyl sulfonate (recorded as III and IV, respectively) were synthesized.
The synthesized surfactants have excellent emulsification ability.