Salt Effects on Formation and Stability of Colloidal Gas Aphrons Produced by Anionic and Zwitterionic Surfactants in Xanthan Gum Solution

Colloids and Interfaces

Aliyar Javadi¹  Mohsen Mahmoudvand¹  Behnam Keshavarzi¹  Alireza Bahramian¹  Kerstin Eckert²  Reinhard Miller³ 

[1] Chemical Engineering Department, Institute of Petroleum Engineering, University of Tehran, Tehran 1417466191, Iran;Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany;Physics Department, Technische Universität Darmstadt, 64289 Darmstadt, Germany;

关键词: colloidal gas aphrons, foam formation and stability, drilling fluid, dynamic surface tension, interfacial rheology, cocoamidopropyl betaine, sodium dodecyl sulfate, nacl;   

DOI  :  10.3390/colloids4010009

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown