Light-scattering and electron microscopy determinations of association structures in W/O microemulsions

• Published in: Journal of colloid and interface science 1978-01, Vol.67 (1), p.16-30
• Main Authors: Sjöblom, Eva, Friberg, Stig
• Format: Article
• Language: English
• ISSN: 0021-9797; 1095-7103; 1095-7103
• DOI: 10.1016/0021-9797(78)90210-2

Light scattering of solutions and electron microscopy of carbon replicas from freeze—fractured samples were used to determine association structures in W/O microemulsions. The results showed the microemulsions to be molecular dispersions at a low water content; association to inverse micelles took place first at a high water content, approximately corresponding to eight molecules of water per soap molecule. Different hydrocarbons gave similar maximal water contents of the microemulsions, showing no influence of the nature of the hydrocarbon on the stability limit of the inverse micelles against a high water content. On the other hand, the onset of association showed a pronounced change with the nature of the hydrocarbon, aromatic hydrocarbons strongly reducing the association concentration. The results explained earlier ambiguities in the literature and also gave a rational reinterpretation of other results.