Facile preparation of multi-functionalized zwitterionic surfactants for the separation of water in Arabian heavy crude oil emulsions

[Display omitted] •Facile method was used to prepare multifunctional zwitterionic surfactants.•Surfactants were applied for demulsification of Arabian crude oil emulsions.•The effect of sulfone functionalization on the demulsification process was studied.•Multifunctional zwitterionic surfactants showed high and fast demulsification efficiency. We report an easy process to prepare new anionic and zwitterionic surfactants to break water in Arabian heavy crude oil emulsions (W/O) with different compositions (10/90, 30/70 and 50/50 vol%). Surfactants were prepared in only two stages using simple methodology. Diethylenetriamine was interacted with three moles of glycidyl 4-nonyl ether followed by the interaction with 3 and 8 mol of 1,3-propanesultone to yield TNDTS-3 and TNDTS-8 respectively. FTIR and NMR spectroscopies were carried out to substantiate the chemical structures of surfactants. Relative solubility number (RSN), surface activity and solubility properties were determined. Demulsification efficiencies and interfacial tension (IFT) of the prepared surfactants were investigated. Our findings demonstrated that increasing propyl sulfonate groups in the surfactant structure improved water solubility, IFT activity and demulsification efficiency. TNDTS-8 achieved 100 % demulsification activities in all W/O emulsions (10/90, 30/70 and 50/50 vol%).