The Effect of Emulsifiers on the Emulsion Stability and Extraction Efficiency of Cr(VI) Using Emulsion Liquid Membranes (ELMs) Formulated with a Green Solvent

• Published in: Membranes (Basel) Vol. 10; no. 4; p. 76
• Main Authors: Anarakdim, Katia, Gutiérrez, Gemma, Cambiella, Ángel, Senhadji-Kebiche, Ounissa, Matos, María
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21-04-2020; MDPI
• Subjects: Aqueous solutions; Chromium; chromium extraction; double emulsion stability; Double emulsions; Efficiency; Emulsifiers; Emulsions; Inspection; Lipophilic; liquid membrane; Liquid membranes; Oils & fats; PGPR; Polyglycerols; Potassium; Size distribution; Solvents; Spectrum analysis; Stability; Sunflower oil; Sunflowers; Trioctylphosphine oxide; vegetable oil; Vegetable oils; Zeta potential; St Louis Missouri; United Kingdom > UK; France; United States > US; Germany; vegetable oil; PGPR; liquid membrane; chromium extraction; double emulsion stability
• ISSN: 2077-0375; 2077-0375
• DOI: 10.3390/membranes10040076

The stability of emulsion liquid membranes (ELMs) and their ability to extract Cr(VI) were investigated. The objective of this study is to compare different ELM formulations using combinations of two hydrophilic (Tween 20 and Tween 80) and two lipophilic (polyglycerol polyricinoleate (PGPR) and Span 80) emulsifiers. TOPO (tri-n-octylphosphine oxide) as a carrier and a green solvent (sunflower oil) were used to provide high extraction efficiency of Cr(VI). All these double emulsions were characterized in droplet size distribution, zeta potential, visual inspection with a microscope, and stability. The best formulation was obtained with PGPR as the inner stabilizer and Tween 80 as the outer stabilizer, leading to Cr(VI) ion removal efficiency of up to 96%.