Kinetics of Surfactant Desorption at an Air–Solution Interface

Handle URI:
http://hdl.handle.net/10754/598688
Title:
Kinetics of Surfactant Desorption at an Air–Solution Interface
Authors:
Morgan, C. E.; Breward, C. J. W.; Griffiths, I. M.; Howell, P. D.; Penfold, J.; Thomas, R. K.; Tucker, I.; Petkov, J. T.; Webster, J. R. P.
Abstract:
The kinetics of re-equilibration of the anionic surfactant sodium dodecylbenzene sulfonate at the air-solution interface have been studied using neutron reflectivity. The experimental arrangement incorporates a novel flow cell in which the subphase can be exchanged (diluted) using a laminar flow while the surface region remains unaltered. The rate of the re-equilibration is relatively slow and occurs over many tens of minutes, which is comparable with the dilution time scale of approximately 10-30 min. A detailed mathematical model, in which the rate of the desorption is determined by transport through a near-surface diffusion layer into a diluted bulk solution below, is developed and provides a good description of the time-dependent adsorption data. A key parameter of the model is the ratio of the depth of the diffusion layer, H c, to the depth of the fluid, Hf, and we find that this is related to the reduced Péclet number, Pe*, for the system, via Hc/Hf = C/Pe*1/2. Although from a highly idealized experimental arrangement, the results provide an important insight into the "rinse mechanism", which is applicable to a wide variety of domestic and industrial circumstances. © 2012 American Chemical Society.
Citation:
Morgan CE, Breward CJW, Griffiths IM, Howell PD, Penfold J, et al. (2012) Kinetics of Surfactant Desorption at an Air–Solution Interface. Langmuir 28: 17339–17348. Available: http://dx.doi.org/10.1021/la304091g.
Publisher:
American Chemical Society (ACS)
Journal:
Langmuir
KAUST Grant Number:
KUK-C1-013-04
Issue Date:
18-Dec-2012
DOI:
10.1021/la304091g
PubMed ID:
23167573
Type:
Article
ISSN:
0743-7463; 1520-5827
Sponsors:
ISIS is acknowledged for the beam time on INTER and STFC and EPSRC for the CASE award for C.E.M. C.J.W.B. and I.M.G. acknowledge Award No. KUK-C1-013-04, made by King Abdullah University of Science and Technology (KAUST), for support. The authors acknowledge P. Carroll, G. Lawton, and W. Ranken at Unilever, Port Sunlight, for the construction of the flow cell.
Appears in Collections:
Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorMorgan, C. E.en
dc.contributor.authorBreward, C. J. W.en
dc.contributor.authorGriffiths, I. M.en
dc.contributor.authorHowell, P. D.en
dc.contributor.authorPenfold, J.en
dc.contributor.authorThomas, R. K.en
dc.contributor.authorTucker, I.en
dc.contributor.authorPetkov, J. T.en
dc.contributor.authorWebster, J. R. P.en
dc.date.accessioned2016-02-25T13:34:28Zen
dc.date.available2016-02-25T13:34:28Zen
dc.date.issued2012-12-18en
dc.identifier.citationMorgan CE, Breward CJW, Griffiths IM, Howell PD, Penfold J, et al. (2012) Kinetics of Surfactant Desorption at an Air–Solution Interface. Langmuir 28: 17339–17348. Available: http://dx.doi.org/10.1021/la304091g.en
dc.identifier.issn0743-7463en
dc.identifier.issn1520-5827en
dc.identifier.pmid23167573en
dc.identifier.doi10.1021/la304091gen
dc.identifier.urihttp://hdl.handle.net/10754/598688en
dc.description.abstractThe kinetics of re-equilibration of the anionic surfactant sodium dodecylbenzene sulfonate at the air-solution interface have been studied using neutron reflectivity. The experimental arrangement incorporates a novel flow cell in which the subphase can be exchanged (diluted) using a laminar flow while the surface region remains unaltered. The rate of the re-equilibration is relatively slow and occurs over many tens of minutes, which is comparable with the dilution time scale of approximately 10-30 min. A detailed mathematical model, in which the rate of the desorption is determined by transport through a near-surface diffusion layer into a diluted bulk solution below, is developed and provides a good description of the time-dependent adsorption data. A key parameter of the model is the ratio of the depth of the diffusion layer, H c, to the depth of the fluid, Hf, and we find that this is related to the reduced Péclet number, Pe*, for the system, via Hc/Hf = C/Pe*1/2. Although from a highly idealized experimental arrangement, the results provide an important insight into the "rinse mechanism", which is applicable to a wide variety of domestic and industrial circumstances. © 2012 American Chemical Society.en
dc.description.sponsorshipISIS is acknowledged for the beam time on INTER and STFC and EPSRC for the CASE award for C.E.M. C.J.W.B. and I.M.G. acknowledge Award No. KUK-C1-013-04, made by King Abdullah University of Science and Technology (KAUST), for support. The authors acknowledge P. Carroll, G. Lawton, and W. Ranken at Unilever, Port Sunlight, for the construction of the flow cell.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleKinetics of Surfactant Desorption at an Air–Solution Interfaceen
dc.typeArticleen
dc.identifier.journalLangmuiren
dc.contributor.institutionUniversity of Oxford, Oxford, United Kingdomen
dc.contributor.institutionISIS Facility, Didcot, United Kingdomen
dc.contributor.institutionUnilever, London, United Kingdomen
kaust.grant.numberKUK-C1-013-04en
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