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Lada ZG, Mathioudakis GN, Soto Beobide A, Andrikopoulos KS, Voyiatzis GA. Generic method for the detection of short & long chain PFAS extended to the lowest concentration levels of SERS capability. CHEMOSPHERE 2024; 363:142916. [PMID: 39043274 DOI: 10.1016/j.chemosphere.2024.142916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 07/19/2024] [Accepted: 07/20/2024] [Indexed: 07/25/2024]
Abstract
The detection of the highly toxic per- and polyfluoroalkyl substances, PFAS, constitutes a challenging task in terms of developing a generic method that could be rapid and applicable simultaneously to both long and short-chain PFAS at ppt concentration level. In the present study, the method introduced by the USA Environmental Protection Agency, EPA, to detect surfactants, using methylene blue, MB, which is identified an ideal candidate for PFAS-MB ion pairing, is extended at the lowest concentration range by a simple additional step that involves the dissociation of the ion pairs in water. In this work, Surface Enhanced Raman Scattering, SERS, is applied via Ag nanocolloidal suspensions to probe MB and indirectly either/or both short-chain (perfluorobutyric acid, PFBA) and long-chain (perfluoloctanoic acid, PFOA) PFAS downt to 5 ppt. This method, which can be further optimized to sub-ppt level via a custom-made SERS-PFAS dedicated Raman system, offers the possibility to be applied to either specific PFAS (both short and long-chain) in a targeted analysis or to total PFAS in a non-targeted analysis at very low detection limits, following any type of MB detection method in aqueous solutions and obviously with any type of SERS substrate.
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Affiliation(s)
- Zoi G Lada
- Foundation for Research and Technology-Hellas, Institute of Chemical Engineering Sciences, (FORTH/ICE-HT), Stadiou Str. Platani, 265 04, Patras, Greece
| | - Georgios N Mathioudakis
- Foundation for Research and Technology-Hellas, Institute of Chemical Engineering Sciences, (FORTH/ICE-HT), Stadiou Str. Platani, 265 04, Patras, Greece
| | - Amaia Soto Beobide
- Foundation for Research and Technology-Hellas, Institute of Chemical Engineering Sciences, (FORTH/ICE-HT), Stadiou Str. Platani, 265 04, Patras, Greece
| | - Konstantinos S Andrikopoulos
- Foundation for Research and Technology-Hellas, Institute of Chemical Engineering Sciences, (FORTH/ICE-HT), Stadiou Str. Platani, 265 04, Patras, Greece; Department of Physics, University of Patras, GR-26504, Patras, Greece
| | - George A Voyiatzis
- Foundation for Research and Technology-Hellas, Institute of Chemical Engineering Sciences, (FORTH/ICE-HT), Stadiou Str. Platani, 265 04, Patras, Greece.
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2
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Pedrazo-Tardajos A, Claes N, Wang D, Sánchez-Iglesias A, Nandi P, Jenkinson K, De Meyer R, Liz-Marzán LM, Bals S. Direct visualization of ligands on gold nanoparticles in a liquid environment. Nat Chem 2024; 16:1278-1285. [PMID: 38937593 DOI: 10.1038/s41557-024-01574-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 06/06/2024] [Indexed: 06/29/2024]
Abstract
The interactions between gold nanoparticles, their surface ligands and the solvent critically influence the properties of these nanoparticles. Although spectroscopic and scattering techniques have been used to investigate their ensemble structure, a comprehensive understanding of these processes at the nanoscale remains challenging. Electron microscopy makes it possible to characterize the local structure and composition but is limited by insufficient contrast, electron beam sensitivity and the requirement for ultrahigh-vacuum conditions, which prevent the investigation of dynamic aspects. Here we show that, by exploiting high-quality graphene liquid cells, we can overcome these limitations and investigate the structure of the ligand shell around gold nanoparticles and at the ligand-gold interface in a liquid environment. Using this graphene liquid cell, we visualize the anisotropy, composition and dynamics of ligand distribution on gold nanorod surfaces. Our results indicate a micellar model for surfactant organization. This work provides a reliable and direct visualization of ligand distribution around colloidal nanoparticles.
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Affiliation(s)
- Adrián Pedrazo-Tardajos
- EMAT-University of Antwerp, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, Antwerp, Belgium
| | - Nathalie Claes
- EMAT-University of Antwerp, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, Antwerp, Belgium
| | - Da Wang
- EMAT-University of Antwerp, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, Antwerp, Belgium
| | - Ana Sánchez-Iglesias
- CIC biomaGUNE, Donostia-San Sebastián, Spain
- Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Donostia-San Sebastián, Spain
| | - Proloy Nandi
- EMAT-University of Antwerp, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, Antwerp, Belgium
| | - Kellie Jenkinson
- EMAT-University of Antwerp, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, Antwerp, Belgium
| | - Robin De Meyer
- EMAT-University of Antwerp, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, Antwerp, Belgium
| | - Luis M Liz-Marzán
- CIC biomaGUNE, Donostia-San Sebastián, Spain
- Centro de Investigación Biomédica en Red, Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
- Cinbio, Universidade de Vigo, Vigo, Spain
| | - Sara Bals
- EMAT-University of Antwerp, Antwerp, Belgium.
- NANOlab Center of Excellence, University of Antwerp, Antwerp, Belgium.
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3
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Tyagi G, Greenfield JL, Jones BE, Sharratt WN, Khan K, Seddon D, Malone LA, Cowieson N, Evans RC, Fuchter MJ, Cabral JT. Light Responsiveness and Assembly of Arylazopyrazole-Based Surfactants in Neat and Mixed CTAB Micelles. JACS AU 2022; 2:2670-2677. [PMID: 36590257 PMCID: PMC9795462 DOI: 10.1021/jacsau.2c00453] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 06/17/2023]
Abstract
The self-assembly of an arylazopyrazole-based photosurfactant (PS), based on cetyltrimethylammonium bromide (CTAB), and its mixed micelle formation with CTAB in aqueous solution was investigated by small angle neutron and X-ray scattering (SANS/SAXS) and UV-vis absorption spectroscopy. Upon UV light exposure, PS photoisomerizes from E-PS (trans) to Z-PS (cis), which transforms oblate ellipsoidal micelles into smaller, spherical micelles with larger shell thickness. Doping PS with CTAB resulted in mixed micelle formation at all stoichiometries and conditions investigated; employing selectively deuterated PS, a monotonic variation in scattering length density and dimensions of the micellar core and shell is observed for all contrasts. The concentration- and irradiance-dependence of the E to Z configurational transition was established in both neat and mixed micelles. A liposome dye release assay establishes the enhanced efficacy of photosurfactants at membrane disruption, with E-PS exhibiting a 4-fold and Z-PS a 10-fold increase in fluorescence signal with respect to pure CTAB. Our findings pave the way for external triggering and modulation of the wide range of CTAB-based biomedical and material applications.
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Affiliation(s)
- Gunjan Tyagi
- Department
of Chemical Engineering, Imperial College
London, London SW7 2AZ, U.K.
- Institute
for Molecular Science and Engineering, Imperial
College London, London SW7 2AZ, U.K.
| | - Jake L. Greenfield
- Institute
for Molecular Science and Engineering, Imperial
College London, London SW7 2AZ, U.K.
- Molecular
Sciences Research Hub, Department of Chemistry, Imperial College London, London W12 0BZ, U.K.
| | - Beatrice E. Jones
- Department
of Materials Science and Metallurgy, University
of Cambridge, Cambridge CB3 OFS, U.K.
- Diamond
Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11
0DE, U.K.
| | - William N. Sharratt
- Department
of Chemical Engineering, Imperial College
London, London SW7 2AZ, U.K.
| | - Kasim Khan
- Department
of Biology, Lund University, 22100 Lund, Sweden
| | - Dale Seddon
- Department
of Chemical Engineering, Imperial College
London, London SW7 2AZ, U.K.
| | - Lorna A. Malone
- Diamond
Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11
0DE, U.K.
| | - Nathan Cowieson
- Diamond
Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11
0DE, U.K.
| | - Rachel C. Evans
- Department
of Materials Science and Metallurgy, University
of Cambridge, Cambridge CB3 OFS, U.K.
| | - Matthew J. Fuchter
- Institute
for Molecular Science and Engineering, Imperial
College London, London SW7 2AZ, U.K.
- Molecular
Sciences Research Hub, Department of Chemistry, Imperial College London, London W12 0BZ, U.K.
| | - João T. Cabral
- Department
of Chemical Engineering, Imperial College
London, London SW7 2AZ, U.K.
- Institute
for Molecular Science and Engineering, Imperial
College London, London SW7 2AZ, U.K.
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Forooqi Motlaq V, Ortega-Holmberg M, Edwards K, Gedda L, Lyngsø J, Pedersen JS, Bergström LM. Investigation of the enhanced ability of bile salt surfactants to solubilize phospholipid bilayers and form mixed micelles. SOFT MATTER 2021; 17:7769-7780. [PMID: 34351343 DOI: 10.1039/d1sm00745a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The self-assembly in mixtures of the anionic bile salt surfactant sodium deoxycholate (NaDC) and the zwitterionic phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) in physiological saline solution has been investigated using light scattering, small-angle X-ray scattering and cryo-transmission electron microscopy. Rather small tri-axial ellipsoidal NaDC-DMPC mixed micelles form at a high content of bile salt in the mixture, which increase in size as an increasing amount of DMPC is incorporated into the micelles. Eventually, the micelles begin to grow substantially in length to form long wormlike micelles. At higher mole fractions of DMPC, the samples become turbid and cryo-TEM measurements reveal the existence of large perforated vesicles (stomatosomes), coexisting with geometrically open disks. To our knowledge, stomatosomes have not been observed before for any bile salt-phospholipid system. Mixed micelles are found to be the sole aggregate structure in a very wide regime of bile salt-phospholipid compositions, i.e. up to about 77 mol% phospholipid in the micelles. This is much higher than the corresponding value of 25 mol% observed for the conventional surfactant hexadecyltrimethylammonium bromide (CTAB) mixed with DMPC in the same solvent. The enhanced ability of bile salt surfactants to solubilize phospholipid bilayers and form mixed micelles is rationalized using bending elasticity theory. From our theoretical analysis, we are able to conclude that amphiphilic molecules rank in the following order of increasing spontaneous curvature: phospholipids < conventional surfactants < bile salts. The bending rigidity of the different amphiphilic molecules increases according to the following sequence: bile salts < conventional surfactants < phospholipids.
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Affiliation(s)
- Vahid Forooqi Motlaq
- Department of Medicinal Chemistry, Pharmaceutical Physical Chemistry, Uppsala University, SE-751 23 Uppsala, Sweden.
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5
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Mathioudakis GN, Soto Beobide A, Anastasiadis SH, Voyiatzis GA. Surface enhanced Raman scattering of brilliant green: Packing density and stabilizing effect of the cationic surfactant CTAB on the “hotspot” spacing. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.125912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Blayo C, Houston JE, King SM, Evans RC. Unlocking Structure-Self-Assembly Relationships in Cationic Azobenzene Photosurfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10123-10134. [PMID: 30071720 DOI: 10.1021/acs.langmuir.8b02109] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Azobenzene photosurfactants are light-responsive amphiphiles that have garnered significant attention for diverse applications including delivery and sorting systems, phase transfer catalysis, and foam drainage. The azobenzene chromophore changes both its polarity and conformation (trans-cis isomerization) in response to UV light, while the amphiphilic structure drives self-assembly. Detailed understanding of the inherent relationship between the molecular structure, physicochemical behavior, and micellar arrangement of azobenzene photosurfactants is critical to their usefulness. Here, we investigate the key structure-function-assembly relationships in the popular cationic alkylazobenzene trimethylammonium bromide (AzoTAB) family of photosurfactants. We show that subtle changes in the surfactant structure (alkyl tail, spacer length) can lead to large variations in the critical micelle concentration, particularly in response to light, as determined by surface tensiometry and dynamic light scattering. Small-angle neutron scattering studies also reveal the formation of more diverse micellar aggregate structures (ellipsoids, cylinders, spheres) than predicted based on simple packing parameters. The results suggest that whereas the azobenzene core resides in the effective hydrophobic segment in the trans-isomer, it forms part of the effective hydrophilic segment in the cis-isomer because of the dramatic conformational and polarity changes induced by photoisomerization. The extent of this shift in the hydrophobic-hydrophilic balance is determined by the separation between the azobenzene core and the polar head group in the molecular structure. Our findings show that judicious design of the AzoTAB structure enables selective tailoring of the surfactant properties in response to light, such that they can be exploited and controlled in a reliable fashion.
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Affiliation(s)
- Camille Blayo
- School of Chemistry and CRANN , University of Dublin, Trinity College , College Green , Dublin 2 , Ireland
| | - Judith E Houston
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) , Forschungszentrum Jülich GmbH , Lichtenbergstr. 1 , 85748 Garching , Germany
| | - Stephen M King
- ISIS Pulsed Neutron Source, STFC, Rutherford Appleton Laboratory , Didcot , Oxfordshire OX11 0QX , U.K
| | - Rachel C Evans
- Department of Materials Science & Metallurgy , University of Cambridge , Cambridge CB3 0FS , U.K
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7
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The influence of n- hexanol on the morphology and composition of CTAB micelles. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2017.12.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Skoglund S, Blomberg E, Wallinder IO, Grillo I, Pedersen JS, Bergström LM. A novel explanation for the enhanced colloidal stability of silver nanoparticles in the presence of an oppositely charged surfactant. Phys Chem Chem Phys 2018; 19:28037-28043. [PMID: 28994441 DOI: 10.1039/c7cp04662f] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural behavior in aqueous mixtures of negatively charged silver nanoparticles (Ag NPs) together with the cationic surfactants cetyltrimethylammonium bromide (CTAB) and dodecyltrimethylammonium chloride (DTAC), respectively, has been investigated using SANS and SAXS. From our SANS data analysis we are able to conclude that the surfactants self-assemble into micellar clusters surrounding the Ag NPs. We are able to quantify our results by means of fitting experimental SANS data with a model based on cluster formation of micelles with very good agreement. Based on our experimental results, we propose a novel mechanism for the stabilization of negatively charged Ag NPs in a solution of positively charged surfactants in which cluster formation of micelles in the vicinity of the particles prevents the particles from aggregating. Complementary SAXS and DLS measurements further support this novel way of explaining stabilization of small hydrophilic nanoparticles in surfactant-containing solutions.
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Affiliation(s)
- Sara Skoglund
- KTH Royal Institute of Technology, School of Chemical Science and Engineering, Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
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9
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Akamatsu M, Suzuki T, Tsuchiya K, Masaki H, Sakai K, Sakai H. Accelerated Recombination of Lophyl Radicals Solubilized in Micelles. CHEM LETT 2018. [DOI: 10.1246/cl.170906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Masaaki Akamatsu
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Taiki Suzuki
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Koji Tsuchiya
- Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Hitoshi Masaki
- School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakuracho, Hachiouji, Tokyo 192-0982, Japan
| | - Kenichi Sakai
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
- Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Hideki Sakai
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
- Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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10
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Rheological Properties and Microstructure Transition in Mixture of Zwitterionic Surfactant, Anionic Surfactant and Salts in Sorbitol/H2O Solvent: 2. Effect of Salts and Sorbitol. J SURFACTANTS DETERG 2017. [DOI: 10.1007/s11743-017-2006-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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Bergström LM, Tehrani-Bagha A, Nagy G. Growth Behavior, Geometrical Shape, and Second CMC of Micelles Formed by Cationic Gemini Esterquat Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:4644-4653. [PMID: 25835031 DOI: 10.1021/acs.langmuir.5b00742] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Micelles formed by novel gemini esterquat surfactants have been investigated with small-angle neutron scattering (SANS). The growth behavior of the micelles is found to differ conspicuously depending on the length of the gemini surfactant spacer group. The gemini surfactant with a long spacer form rather small triaxial ellipsoidal tablet-shaped micelles that grow weakly with surfactant concentration in the entire range of measured concentrations. Geminis with a short spacer, on the other hand, form weakly growing oblates or tablets at low concentrations that start to grow much more strongly into polydisperse rodlike or wormlike micelles at higher concentrations. The latter behavior is consistent with the presence of a second CMC that marks the transition from the weakly to the strongly growing regime. It is found that the growth behavior in terms of aggregation number as a function of surfactant concentration always appear concave in weakly growing regimes, while switching to convex behavior in strongly growing regimes. As a result, we are able to determine the second CMC of the geminis with short spacer by means of suggesting a rather precise definition of it, located at the point of inflection of the growth curve that corresponds to the transition from concave to convex growth behavior. Our SANS results are rationalized by comparison with the recently developed general micelle model. In particular, this theory is able to explain and reproduce the characteristic appearances of the experimental growth curves, including the presence of a second CMC and the convex strongly growing regime beyond. By means of optimizing the agreement between predictions from the general micelle model and results from SANS experiments, we are able to determine the three bending elasticity constants spontaneous curvature, bending rigidity, and saddle-splay constant for each surfactant.
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Affiliation(s)
- L Magnus Bergström
- †Department of Chemistry, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
| | - Alireza Tehrani-Bagha
- ‡Department of Chemical and Petroleum Engineering, American University of Beirut, Beirut, Lebanon
| | - Gergely Nagy
- §Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Switzerland
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13
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Bergström LM. Explaining the growth behavior of surfactant micelles. J Colloid Interface Sci 2014; 440:109-18. [PMID: 25460696 DOI: 10.1016/j.jcis.2014.10.054] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/10/2014] [Accepted: 10/18/2014] [Indexed: 11/30/2022]
Abstract
The growth behavior of surfactant micelles has been investigated from a theoretical point of view. It is demonstrated that predictions deduced from the spherocylindrical micelle model, which considers micelles that are only able to grow in the length direction, are inconsistent with experimental measurements. Accordingly, the rise in aggregation numbers above a certain concentration, roughly corresponding to the second critical micelle concentration, appears to be much stronger than predicted by the spherocylindrical micelle model. On the other hand, predictions deduced from the general micelle model, which considers micelles that are able to grow with respect to both width and length, show excellent agreement with experimental observations. The latter theory is based on bending elasticity and it is demonstrated that the associated three parameters spontaneous curvature, bending rigidity and saddle-splay constant may all be determined for a micellar system from experimental measurements of the aggregation number as a function of surfactant concentration. The three parameters turn out to influence the appearance of a micellar growth curve rather differently. In accordance, the location of the second cmc is mainly determined by the saddle-splay constant and the bending rigidity. The shape of the growth curve, when going from the region of weakly growing micelles at low surfactant concentrations to strongly growing micelles above the second cmc, is mainly influenced by the bending rigidity.
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Affiliation(s)
- L Magnus Bergström
- KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Surface and Corrosion Science, SE-10044 Stockholm, Sweden.
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