Optimizing organoclay stabilized Pickering emulsions

Yannan Cui, Mhairi Threlfall, Jeroen S. van Duijneveldt

Research output: Contribution to journalArticle (Academic Journal)peer-review

53 Citations (Scopus)

Abstract

Oil-in-water emulsions were prepared using montmorillonite clay platelets, pre-treated with quaternary amine surfactants. In previous work, cetyl trimethylammonium bromide (CTAB) has been used. In this study, two more hydrophilic quaternary amine surfactants, Berol R648 and Ethoquad C/12, were used and formed Pickering emulsions, which were more stable than the emulsions prepared using CTAB coated clay. The droplets were also more mono-disperse. The most hydrophilic surfactant Berol R648 stabilizes the emulsions best. Salt also plays an important role in forming a stable emulsion. The droplet size decreases with surfactant concentration and relatively mono-disperse droplets can be obtained at moderate surfactant concentrations. The time evolution of the droplet size indicates a good stability to coalescence in the presence of Berol R648. Using polarizing microscopy, the clay platelets were found to be lying flat at the water oil interface. However, a significant fraction (about 90%) of clay stayed in the water phase and the clay particles at the water-oil interface formed stacks, each consisting of four clay platelets on average. (C) 2011 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)665-671
Number of pages7
JournalJournal of Colloid and Interface Science
Volume356
Issue number2
DOIs
Publication statusPublished - 15 Apr 2011

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