Synthesis and properties of double-chain single-head acetamidinium bicarbonate switchable surfactants

Abstract

A series of switchable surfactants with double hydrophobic chains and a single hydrophilic head N,N’-dialkylacetamidinium bicarbonate with an alkyl length between diC8 and diC12 were synthesized by using new approaches. The structures of acetamidinium bicarbonate were characterized by ¹H NMR and ESI-MS spectroscopy. The surface activity in aqueous solution of N,N’-dialkylacetamidinium bicarbonate and N’-alkyl-N,N-dimethylacetamidinium were compared by surface tension methods. Some surface activity parameters were studied, such as cmc, γ_cmc, pC₂₀, cmc/C₂₀, Γ_max, and A_min. The results indicated that double-chain surfactant was superior to single-chain surfactant and showed more excellent surface activity. The switchability was confirmed by monitoring the conductivity of a solution of amidine in ethanol and their effect in emulsion stability was also investigated.

Graphical Abstract

Keywords:

• Acetamidinium bcarbonate
• double-chain
• surfactant
• surfactivity
• switchable

Acknowledgments

The authors are thankful to the teachers and classmates who offered help for the whole experimental process.

Disclosure statement

No potential conflict of interest was reported by the authors.