Salt effects on formation and stability of colloidal gas aphrons produced by anionic and zwitterionic surfactants in xanthan gum solution

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Behnam Keshavarzi - , Professur für Transportprozesse an Grenzflächen (gB HZDR), University of Tehran, Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Autor:in)
  • Mohsen Mahmoudvand - , University of Tehran (Autor:in)
  • Aliyar Javadi - , University of Tehran, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Technische Universität Dresden (Autor:in)
  • Alireza Bahramian - , University of Tehran (Autor:in)
  • Reinhard Miller - , Technische Universität Darmstadt (Autor:in)
  • Kerstin Eckert - , Professur für Transportprozesse an Grenzflächen (gB HZDR), Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Autor:in)

Abstract

This work is devoted to the influence of NaCl salt concentration on the formation and stability of colloidal gas aphrons (CGA) produced by the anionic surfactant sodium dodecyl sulfate (SDS) and zwitterionic surfactant coco amido propyl betaine (CAPB) in the presence of xanthan gum (XG) as a stabilizer. Dynamic surface tension measurements as well as volume and half-life time of the produced foams are considered for stability analysis. A sharp decrease of the half-life time and volume of the CGAs at NaCl concentrations larger than 20,000 ppm was observed, which was attributed to the precipitation of SDS in the solution. The mentioned SDS precipitation altered the dynamic surface tension behavior, dilational surface elasticity, and turbidity of the solution. The main reason for the precipitation of SDS is the increased Krafft point caused by the addition of salt. However, for the zwitterionic surfactant CAPB, the effects of added NaCl on the interfacial properties required for CGAs production was negligible due to the simultaneous effects on the cationic and anionic head groups in the CAPB leading to negligible changes in the net repulsion forces. Yet, an overall reduction in the half-life time of CGAs with increasing salt concentration, even when we have no precipitation, was observed for both surfactants, which could be explained by the reduction in the ability of XG to increase the viscosity with increasing salt concentration.

Details

OriginalspracheEnglisch
Aufsatznummer9
FachzeitschriftColloids and Interfaces
Jahrgang4
Ausgabenummer1
PublikationsstatusVeröffentlicht - März 2020
Peer-Review-StatusJa

Schlagworte

Schlagwörter

  • Cocoamidopropyl betaine, Colloidal gas aphrons, Drilling fluid, Dynamic surface tension, Foam formation and stability, Interfacial rheology, NaCl, Sodium dodecyl sulfate