The effect of the hydrocarbon-water interface structure on the behavior of an emulsion stabilized with dodecanephosphonic acid

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...

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Bibliographic Details
Authors: Verdinelli, Valeria, Messina, Paula Verónica, Schulz, Eduardo Nicolás, Salinas, Daniel Ricardo, Vuano, Bruno Mario, Schulz, Pablo Carlos
Format: article
Status:Published version
Publication Date:2010
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/80051
Online Access:http://hdl.handle.net/11336/80051
Access Level:Open access
Keyword:Dodecanephosphonic Acid
Emulsion
Emulsion Inversion
Hydrogen Bond
Oil/Water Interface
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
Description
Summary: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.