Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Record number 446061
Title A liquid CO2-compatible hydrocarbon surfactant: experiment and modelling
Author(s) Banerjee, S.; Kleijn, J.M.; Cohen Stuart, M.A.; Leermakers, F.A.M.
Source Physical Chemistry Chemical Physics 15 (2013)45. - ISSN 1463-9076 - p. 19879 - 19892.
DOI https://doi.org/10.1039/c3cp52571f
Department(s) Physical Chemistry and Colloid Science
WIMEK
Publication type Refereed Article in a scientific journal
Publication year 2013
Keyword(s) block copolymer adsorption - carbon-dioxide - statistical thermodynamics - molecular simulation - interfacial-tension - reverse micelles - systems - microemulsions - temperature - pressures
Abstract Surfactants soluble in liquid CO2 are rare and knowledge on interfacial and self-assembly behaviour is fragmented. We found that polyoxyethylene (5) isooctylphenyl ether is interfacially active at the water–liquid CO2 interface. Water–liquid CO2 interfacial tension was measured at various surfactant concentrations at 50 bar and 283 K using the pendant drop method, and a CMC like cusp was observed at a surfactant concentration of 50 mM in the bulk liquid CO2. This system was modelled applying the self-consistent field theory of Scheutjens and Fleer (SF-SCF). We use a free-volume approach, wherein the chemical potential of the vacancies was linked to the pressure and the molecules were described using a freely-jointed chain model on a united atom level. The model indicates that typically the water–vapour interface is wet by CO2. Interestingly, a window of partial wetting was identified at the water–vapour interface as a function of the chemical potential of the surfactant. The second-order nature of both wetting transitions is attributed to the close proximity to the critical point of the CO2–vapour system. Furthermore, the SF-SCF theory was used to study the self-assembly of the surfactant in bulk CO2 or water, focusing on the three-phase coexistence, that is at P/Psat = 1. Above 40 mM in the CO2-rich phase, the theory indicates stable water swollen reverse micelles with an aggregation number of 100. The analysis further shows the stability of compressible CO2-swollen surfactant bilayers in the bulk water phase at elevated surfactant concentrations. Finally it was found that the critical reverse micellar concentration (in liquid CO2) increases and the aggregation number decreases with increasing pressure.
Comments
There are no comments yet. You can post the first one!
Post a comment
 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.