Sodium Alkyl Ether Sulfonates (SAES): Dual Anionic-Nonionic Behavior in Synthetic Brine Having High Salinity and Hardness

Said Al-Faraji, Rashid S. Al-Maamari, Mohamed Aoudia*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Due to the presence of non-sulfonated residual alkyl ether (AE), sodium alkyl ether sulfonate (SAES) may exhibit clear point-cloud point solubilization behavior in brine. Accordingly, the effect of temperature on the compatibility of iC17EOxS (x = 7 and 10), nC17EO10S, along with their analogous nonionic surfactants iC17EOxH (x = 7 and 10) and nC17EO10, in addition to iC9EO14 in brine has been investigated. Depending on their molecular structures, these surfactants exhibited concentration-dependent clear point and cloud point solubilization behavior. The cloud point was associated with the AE component whereas the clear point was attributed to the sulfonated one. Interestingly, an increase in the cloud point of the nonionic component with respect to the corresponding nonionic AE (100 % active) was observed. Adding iC9EO14 (100 % active) to iC17EO7S (xan = 0.0-0.362) resulted in a significant decrease in the clear point of iC17EO7S from above 100°C to below 22°C with a concomitant increase in iC17EO7/iC9EO14 mixture cloud point from 68°C. (xan = 0) to 72°C (xan = 0.325). This relatively modest increase by 4°C was attributed to the interrelationship of different competitive mechanisms, namely an increase in mixed micelle charge with increasing xan, the dehydration of OE groups via ion (SO3-)-dipole (O → CH2) interactions, and possible shielding of SO3- groups by iC9EO14 nearby extended EO groups. To the best of our knowledge, this is the first instance where dual anionic-nonionic solubilization behavior of SAES in brine characterized by high salinity and hardness is being reported.

Original languageEnglish
Pages (from-to)113-121
Number of pages9
JournalJournal of Surfactants and Detergents
Issue number1
Publication statusPublished - Jan 1 2015


  • Alkyl ether sulfonates
  • Clear point
  • Cloud point
  • Compatibility
  • Enhanced oil recovery
  • Intermicellar interaction
  • Mixed micelle

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Chemical Engineering(all)
  • Surfaces, Coatings and Films


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