Imperial College London
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ProfessorJoaoCabral

Faculty of Engineering, Department of Chemical Engineering

Professor of Soft Matter
 
 
 
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Contact

 

+44 (0)20 7594 5571j.cabral Website

 
 
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Assistant

 

Mrs Sarah Payne +44 (0)20 7594 5567

 
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Location

 

517AACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Rafique:2020:10.1039/d0sm00982b,
author = {Rafique, AS and Khodaparast, S and Poulos, AS and Sharratt, WN and Robles, ESJ and Cabral, JT},
doi = {10.1039/d0sm00982b},
journal = {Soft Matter},
pages = {7835--7844},
title = {Micellar structure and transformations in sodium alkylbenzenesulfonate (NaLAS) aqueous solutions: effects of concentration, temperature, and salt},
url = {http://dx.doi.org/10.1039/d0sm00982b},
volume = {16},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - We investigate the shape, dimensions, and transformation pathways of micelles of linear sodium alkylbenzenesulfonate (NaLAS), a common anionic surfactant, in aqueous solution. Employing Small Angle Neutron Scattering (SANS) and surface tensiometry, we quantify the effects of surfactant concentration (0.6–15 wt%), temperature (5–40 °C) and added salt (≤0.35 M Na2SO4). Spherical micelles form at low NaLAS (≤2.6 wt%) concentration in water, and become elongated with increasing concentration and decreasing temperature. Addition of salt reduces the critical micelle concentration (CMC) and thus promotes the formation of micelles. At fixed NaLAS concentration, salt addition causes spherical micelles to grow into cylindrical micelles, and then multilamellar vesicles (MLVs), which we examine by SANS and cryo-TEM. Above a threshold salt concentration, the MLVs reach diameters of 100 s of nm to few μm, eventually causing precipitation. While the salt concentrations associated with the micelle-to-cylinder transformation increase only slightly with temperature, those required for the cylinder-to-MLV transformation exhibit a pronounced, linear temperature dependence, which we examine in detail. Our study establishes a solution structure map for this model anionic surfactant in water, quantifying the combined roles of concentration, temperature and salt, at practically relevant conditions.
AU  - Rafique,AS
AU  - Khodaparast,S
AU  - Poulos,AS
AU  - Sharratt,WN
AU  - Robles,ESJ
AU  - Cabral,JT
DO  - 10.1039/d0sm00982b
EP  - 7844
PY  - 2020///
SN  - 1744-683X
SP  - 7835
TI  - Micellar structure and transformations in sodium alkylbenzenesulfonate (NaLAS) aqueous solutions: effects of concentration, temperature, and salt
T2  - Soft Matter
UR  - http://dx.doi.org/10.1039/d0sm00982b
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000562593800015&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://pubs.rsc.org/en/content/articlelanding/2020/SM/D0SM00982B#!divAbstract
UR  - http://hdl.handle.net/10044/1/83427
VL  - 16
ER  -
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