Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
595144 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2010 | 6 Pages |
Abstract
We studied the phase transition of petroleum ether/water/n-dodecanephosphonic acid (DPA) from W/O to W/O/W emulsion when the neutralization degree (nd) of dodecanephosphonic acid (DPA) with NaOH was changed. We concluded that a phase transition from W/O emulsion to W/O/W emulsion occurs when nd ≈ 0.47 due to a change in the structure of the polar layer at the oil/water interface from a tightly hydrogen-bonded layer to a less compact layer formed by –PO3H2 and –PO3H− groups in favor of an inversion. The W/O/W emulsion is probably caused by a partition of acid molecules in the water droplets interface inside the oil droplets, and monosodium phosphonate molecules at the external interface of oil droplets.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Valeria Verdinelli, Paula V. Messina, Eduardo N. Schulz, Daniel Salinas, Bruno Vuano, Pablo C. Schulz,