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Hardt M, Honnigfort C, Carrascosa-Tejedor J, Braun MG, Winnall S, Glikman D, Gutfreund P, Campbell RA, Braunschweig B. Photoresponsive arylazopyrazole surfactant/PDADMAC mixtures: reversible control of bulk and interfacial properties. NANOSCALE 2024; 16:9975-9984. [PMID: 38695540 DOI: 10.1039/d3nr05414d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2024]
Abstract
In many applications of polyelectrolyte/surfactant (P/S) mixtures, it is difficult to fine-tune them after mixing the components without changing the sample composition, e.g. pH or the ionic strength. Here we report on a new approach where we use photoswitchable surfactants to enable drastic changes in both the bulk and interfacial properties. Poly(diallyldimethylammonium chloride) (PDADMAC) mixtures with three alkyl-arylazopyrazole butyl sulfonates (CnAAP) with -H, -butyl and -octyl tails are applied and E/Z photoisomerization of the surfactants is used to cause substantially different hydrophobic interactions between the surfactants and PDADMAC. These remotely controlled changes affect significantly the P/S binding and allows for tuning both the bulk and interfacial properties of PDADMAC/CnAAP mixtures through light irradiation. For that, we have fixed the surfactant concentrations at values where they exhibit pronounced surface tension changes upon E/Z photoisomerization with 365 nm UV light (Z) and 520 nm green (E) light and have varied the PDADMAC concentration. The electrophoretic mobility can be largely tuned by photoisomerisation of CnAAP surfactants and P/S aggregates, which can even exhibit a charge reversal from negative to positive values or vice versa. In addition, low colloidal stability at equimolar concentrations of PDADMAC with CnAAP surfactants in the E configuration lead to the formation of large aggregates in the bulk which can be broken up by irradiation with UV light when the surfactant's alkyl chain is short enough (C0AAP). Vibrational sum-frequency generation (SFG) spectroscopy reveals changes at the interface similar to the bulk, where the charging state at air-water interfaces can be modified with light irradiation. Using SFG spectroscopy, we interrogated the O-H stretching modes of interfacial H2O and provide qualitative information on surface charging that is complemented by neutron reflectometry, from which we resolved the surface excesses of PDADMAC and CnAAP at the air-water interface, independently.
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Affiliation(s)
- Michael Hardt
- Institute of Physical Chemistry and Center for Soft Nanoscience, University of Münster, Corrensstraße 28/30, 48149 Münster, Germany.
| | - Christian Honnigfort
- Institute of Physical Chemistry and Center for Soft Nanoscience, University of Münster, Corrensstraße 28/30, 48149 Münster, Germany.
| | - Javier Carrascosa-Tejedor
- Institut Laue-Langevin (ILL), 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
- Division of Pharmacy & Optometry, University of Manchester, Manchester M13 9PT, UK
| | - Marius G Braun
- Institute of Physical Chemistry and Center for Soft Nanoscience, University of Münster, Corrensstraße 28/30, 48149 Münster, Germany.
| | - Samuel Winnall
- Institut Laue-Langevin (ILL), 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
- Division of Pharmacy & Optometry, University of Manchester, Manchester M13 9PT, UK
| | - Dana Glikman
- Institute of Physical Chemistry and Center for Soft Nanoscience, University of Münster, Corrensstraße 28/30, 48149 Münster, Germany.
| | - Philipp Gutfreund
- Institut Laue-Langevin (ILL), 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Richard A Campbell
- Division of Pharmacy & Optometry, University of Manchester, Manchester M13 9PT, UK
| | - Björn Braunschweig
- Institute of Physical Chemistry and Center for Soft Nanoscience, University of Münster, Corrensstraße 28/30, 48149 Münster, Germany.
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2
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Weiand E, Koenig PH, Rodriguez-Ropero F, Roiter Y, Angioletti-Uberti S, Dini D, Ewen JP. Boundary Lubrication Performance of Polyelectrolyte-Surfactant Complexes on Biomimetic Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:7933-7946. [PMID: 38573738 PMCID: PMC11025133 DOI: 10.1021/acs.langmuir.3c03737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/20/2024] [Accepted: 03/20/2024] [Indexed: 04/05/2024]
Abstract
Aqueous mixtures of oppositely charged polyelectrolytes and surfactants are useful in many industrial applications, such as shampoos and hair conditioners. In this work, we investigate the friction between biomimetic hair surfaces in the presence of adsorbed complexes formed from cationic polyelectrolytes and anionic surfactants in an aqueous solution. We apply nonequilibrium molecular dynamics (NEMD) simulations using the coarse-grained MARTINI model. We first developed new MARTINI parameters for cationic guar gum (CGG), a functionalized, plant-derived polysaccharide. The complexation of CGG and the anionic surfactant sodium dodecyl sulfate (SDS) on virgin and chemically damaged biomimetic hair surfaces was studied using a sequential adsorption approach. We then carried out squeeze-out and sliding NEMD simulations to assess the boundary lubrication performance of the CGG-SDS complex compressed between two hair surfaces. At low pressure, we observe a synergistic friction behavior for the CGG-SDS complex, which gives lower shear stress than either pure CGG or SDS. Here, friction is dominated by viscous dissipation in an interfacial layer comprising SDS and water. At higher pressures, which are probably beyond those usually experienced during hair manipulation, SDS and water are squeezed out, and friction increases due to interdigitation. The outcomes of this work are expected to be beneficial to fine-tune and screen sustainable hair care formulations to provide low friction and therefore a smooth feel and reduced entanglement.
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Affiliation(s)
- Erik Weiand
- Department
of Mechanical Engineering, Imperial College
London, South Kensington Campus, London SW7 2AZ, U.K.
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - Peter H. Koenig
- Corporate
Functions Analytical and Data & Modeling Sciences, Mason Business
Center, The Procter and Gamble Company, Mason, Ohio 45040, United States
| | - Francisco Rodriguez-Ropero
- Corporate
Functions Analytical and Data & Modeling Sciences, Mason Business
Center, The Procter and Gamble Company, Mason, Ohio 45040, United States
| | - Yuri Roiter
- Corporate
Functions Analytical and Data & Modeling Sciences, Mason Business
Center, The Procter and Gamble Company, Mason, Ohio 45040, United States
| | - Stefano Angioletti-Uberti
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
- Department
of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - Daniele Dini
- Department
of Mechanical Engineering, Imperial College
London, South Kensington Campus, London SW7 2AZ, U.K.
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
| | - James P. Ewen
- Department
of Mechanical Engineering, Imperial College
London, South Kensington Campus, London SW7 2AZ, U.K.
- Institute
of Molecular Science and Engineering, Imperial
College London, South
Kensington Campus, London SW7 2AZ, U.K.
- Thomas
Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
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3
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Kaga H, Orita M, Endo K, Akamatsu M, Sakai K, Sakai H. Interaction between Sophorolipids and β-glucan in Aqueous Solutions. J Oleo Sci 2024; 73:169-176. [PMID: 38311407 DOI: 10.5650/jos.ess23189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024] Open
Abstract
Skin disorders, including acne vulgaris, atopic dermatitis, and rosacea, are characterized by the presence of biofilms, which are communities of microorganisms. The mechanical stability of biofilms is attributed to one of their constituents-polysaccharides-which are secreted by microorganisms. Sophorolipids are biosurfactants with biofilm disruption and removal abilities and are expected to become alternatives for classical petrochemical-based surfactants in cosmetics. In this study, we investigated the influence of sophorolipids on β-glucan such as dispersion status, interaction mechanism, and configuration change as a model polysaccharide of biofilm in aqueous solution. Dynamic light scattering measurements showed that sophorolipids interfere with the aggregation of β- glucan in aqueous solutions. In contrast, sodium dodecyl sulfate (SDS), which is used as a typical surfactant reference, promotes the aggregation of β-glucan. The interaction between sophorolipids and β-glucan were investigated using surface tension measurements and isothermal titration calorimetry (ITC). Surface tension increased only near critical micelle concentration (CMC) region of sophorolipids in the presence of β-glucan. This suggests that the interaction occurred in the solution rather than at the air-liquid interface. Moreover, the results of ITC indicate that hydrophobic interactions were involved in this interaction. In addition, the results of optical rotation measurements indicate that sophorolipids did not unfold the triple helical structure of β-glucan. β-glucan dispersion was expected to be caused steric hindrance and electrostatic repulsion when sophorolipids interacted with β-glucan via hydrophobic interactions owing to the unique molecular structure of sophorolipids attributed by a bulky sugar moiety and a carboxyl functional group. These results demonstrated unique performances of sophorolipids on β-glucan and provided more insights on the efficacy of sophorolipids as good anti-biofilms.
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Affiliation(s)
- Hiroaki Kaga
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science
- Research & Innovation Center, Nihon L'Oréal K.K
| | | | - Koji Endo
- Research & Innovation Center, Nihon L'Oréal K.K
| | - Masaaki Akamatsu
- Department of Chemistry and Biotechnology, Faculty of Engineering, Tottori University
| | - Kenichi Sakai
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science
- Research Institute for Science and Technology, Tokyo University of Science
| | - Hideki Sakai
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science
- Research Institute for Science and Technology, Tokyo University of Science
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4
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Weiand E, Rodriguez-Ropero F, Roiter Y, Koenig PH, Angioletti-Uberti S, Dini D, Ewen JP. Effects of surfactant adsorption on the wettability and friction of biomimetic surfaces. Phys Chem Chem Phys 2023; 25:21916-21934. [PMID: 37581271 DOI: 10.1039/d3cp02546b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
The properties of solid-liquid interfaces can be markedly altered by surfactant adsorption. Here, we use molecular dynamics (MD) simulations to study the adsorption of ionic surfactants at the interface between water and heterogeneous solid surfaces with randomly arranged hydrophilic and hydrophobic regions, which mimic the surface properties of human hair. We use the coarse-grained MARTINI model to describe both the hair surfaces and surfactant solutions. We consider negatively-charged virgin and bleached hair surface models with different grafting densities of neutral octadecyl and anionic sulfonate groups. The adsorption of cationic cetrimonium bromide (CTAB) and anionic sodium dodecyl sulfate (SDS) surfactants from water are studied above the critical micelle concentration. The simulated adsorption isotherms suggest that cationic surfactants adsorb to the surfaces via a two-stage process, initially forming monolayers and then bilayers at high concentrations, which is consistent with previous experiments. Anionic surfactants weakly adsorb via hydrophobic interactions, forming only monolayers on both virgin and medium bleached hair surfaces. We also conduct non-equilibrium molecular dynamics simulations, which show that applying cationic surfactant solutions to bleached hair successfully restores the low friction seen with virgin hair. Friction is controlled by the combined surface coverage of the grafted lipids and the adsorbed CTAB molecules. Treated surfaces containing monolayers and bilayers both show similar friction, since the latter are easily removed by compression and shear. Further wetting MD simulations show that bleached hair treated with CTAB increases the hydrophobicity to similar levels seen for virgin hair. Treated surfaces containing CTAB monolayers with the tailgroups pointing predominantly away from the surface are more hydrophobic than bilayers due to the electrostatic interactions between water molecules and the exposed cationic headgroups.
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Affiliation(s)
- Erik Weiand
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - Francisco Rodriguez-Ropero
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Mason, 45040 Ohio, USA
| | - Yuri Roiter
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Mason, 45040 Ohio, USA
| | - Peter H Koenig
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Mason, 45040 Ohio, USA
| | - Stefano Angioletti-Uberti
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Department of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - Daniele Dini
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - James P Ewen
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
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5
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Sanders JM, Coscia BJ, Fonari A, Misra M, Mileo PGM, Giesen DJ, Browning AR, Halls MD. Exploring the Effects of Wetting and Free Fatty Acid Deposition on an Atomistic Hair Fiber Surface Model Incorporating Keratin-Associated Protein 5-1. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5263-5274. [PMID: 37014946 DOI: 10.1021/acs.langmuir.2c03063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The complex development of cosmetic and medical formulations relies on an ever-growing accuracy of predictive models of hair surfaces. Hitherto, modeling efforts have focused on the description of 18-methyl eicosanoic acid (18-MEA), the primary fatty acid covalently attached to the hair surface, without explicit modeling of the protein layer. Herein, the molecular details of the outermost surface of the human hair fiber surface, also called the F-layer, were studied using molecular dynamics (MD) simulations. The F-layer is composed primarily of keratin-associated proteins KAP5 and KAP10, which are decorated with 18-MEA on the outer surface of a hair fiber. In our molecular model, we incorporated KAP5-1 and evaluated the surface properties of 18-MEA through MD simulations, resulting in 18-MEA surface density, layer thickness, and tilt angles in agreement with previous experimental and computational studies. Subsequent models with reduced 18-MEA surface density were also generated to mimic damaged hair surfaces. Response to wetting of virgin and damaged hair showed rearrangement of 18-MEA on the surface, allowing for water penetration into the protein layer. To demonstrate a potential use case for these atomistic models, we deposited naturally occurring fatty acids and measured 18-MEA's response in both dry and wet conditions. As fatty acids are often incorporated in shampoo formulations, this work demonstrates the ability to model the adsorption of ingredients on hair surfaces. This study illustrates, for the first time, the complex behavior of a realistic F-layer at the molecular level and opens up the possibility of studying the adsorption behavior of larger, more complex molecules and formulations.
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Affiliation(s)
| | | | - Alexandr Fonari
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | - Mayank Misra
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | | | - David J Giesen
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | | | - Mathew D Halls
- Schrödinger, LLC, New York, New York 10036-4041, United States
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6
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Weiand E, Ewen JP, Roiter Y, Koenig PH, Page SH, Rodriguez-Ropero F, Angioletti-Uberti S, Dini D. Nanoscale friction of biomimetic hair surfaces. NANOSCALE 2023; 15:7086-7104. [PMID: 36987934 DOI: 10.1039/d2nr05545g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
We investigate the nanoscale friction between biomimetic hair surfaces using chemical colloidal probe atomic force microscopy experiments and nonequilibrium molecular dynamics simulations. In the experiments, friction is measured between water-lubricated silica surfaces functionalised with monolayers formed from either octadecyl or sulfonate groups, which are representative of the surfaces of virgin and ultimately bleached hair, respectively. In the simulations, friction is monitored between coarse-grained model hair surfaces with different levels of chemical damage, where a specified amount of grafted octadecyl groups are randomly replaced with sulfonate groups. The sliding velocity dependence of friction in the simulations can be described using an extended stress-augmented thermally activation model. As the damage level increases in the simulations, the friction coefficient generally increases, but its sliding velocity-dependence decreases. At low sliding velocities, which are closer to those encountered experimentally and physiologically, we observe a monotonic increase of the friction coefficient with damage ratio, which is consistent with our new experiments using biomimetic surfaces and previous ones using real hair. This observation demonstrates that modified surface chemistry, rather than roughness changes or subsurface damage, control the increase in nanoscale friction of bleached or chemically damaged hair. We expect the methods and biomimetic surfaces proposed here to be useful to screen the tribological performance of hair care formulations both experimentally and computationally.
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Affiliation(s)
- Erik Weiand
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - James P Ewen
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - Yuri Roiter
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Mason, 45040 Ohio, USA
| | - Peter H Koenig
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Mason, 45040 Ohio, USA
| | - Steven H Page
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Mason, 45040 Ohio, USA
| | - Francisco Rodriguez-Ropero
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Mason, 45040 Ohio, USA
| | | | - Daniele Dini
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
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7
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Labarre L, Squillace O, Liu Y, Fryer PJ, Kaur P, Whitaker S, Marsh JM, Zhang ZJ. Hair surface interactions against different chemical functional groups as a function of environment and hair condition. Int J Cosmet Sci 2023; 45:224-235. [PMID: 36683407 PMCID: PMC10946710 DOI: 10.1111/ics.12834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The nature and magnitude of molecular interactions on hair surfaces underpin the design of formulated products, of which the application involves a competitive adsorption process between cationic surfactants, fatty alcohols and surface actives such as silicone. The knowledge of molecular interaction with hair surface will not only provide insight on the surface binding affinity but also offer an effective methodology in characterizing surface deposits. METHODS Untreated and chemically treated hair samples were treated with either conditioner chassis alone (gel network) or conditioner chassis plus silicone (chassis/TAS). Hair surface interactions against four different chemical functional groups, namely methyl (-CH3 ), acid (-COOH), amine (-NH2 ) and hydroxyl (-OH), were quantified in both ambient and aqueous environment using Chemical Force Microscopy, a method based on atomic force microscopy (AFM). RESULTS Surface adhesion on hair in ambient is dominated by capillary force that is determined by both the wettability of hair fibre (hydrophobic vs. hydrophilic), presence of any deposits and the chemical functionality of the AFM cantilever. Capillary force is diminished and replaced by electrostatic interaction when polar groups are present on both hair and AFM cantilever. A distinctively different force, hydrophobic interaction, plays a major role when virgin hair and hydrophobic functionalized AFM cantilever make contact in water. CONCLUSION Results acquired by AFM cantilevers of different functional groups show that hydrophobic interaction is a key driver for deposition on virgin hair, whilst electrostatic interaction is the most important one for bleached hair. Interfacial conformation of chassis components upon deposition is determined by the hair surface properties. Our study highlights the possibility of a range of polar groups, not necessarily negatively charged, on the damaged hair. Unlike conventional surface chemical analysis method, it is possible to quantitatively evaluate the interfacial conformation of deposited surface actives on hair, which identifies the target moieties for conditioning products on different types of hair.
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Affiliation(s)
- Leslie Labarre
- School of Chemical EngineeringUniversity of Birmingham, EdgbastonBirminghamUK
| | - Ophélie Squillace
- School of Chemical EngineeringUniversity of Birmingham, EdgbastonBirminghamUK
| | - Yu Liu
- School of Chemical EngineeringUniversity of Birmingham, EdgbastonBirminghamUK
| | - Peter J. Fryer
- School of Chemical EngineeringUniversity of Birmingham, EdgbastonBirminghamUK
| | - Preeti Kaur
- The Procter & Gamble CompanyMason Business CentreMasonOhioUSA
| | - Shane Whitaker
- The Procter & Gamble CompanyMason Business CentreMasonOhioUSA
| | | | - Zhenyu J. Zhang
- School of Chemical EngineeringUniversity of Birmingham, EdgbastonBirminghamUK
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8
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Nonomura Y, Omori M, Kikuchi K. Friction Dynamics of Foaming Body Cleansers under Sinusoidal Motion. J Oleo Sci 2023; 72:171-177. [PMID: 36631106 DOI: 10.5650/jos.ess22333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The friction characteristics of foaming body cleansers determine skin physical irritation, as well as the usability of the products. In this study, the friction of foam formed by a commercial body cleanser was evaluated using a sinusoidal-motion friction evaluation system. The friction profile of the foam was a hydrodynamic stable pattern, where the friction force increased with increasing velocity. In addition, soapbased cleansers, containing polyols, showed large friction coefficients. These properties suggest that the mechanical properties of the interfacial film and viscosity of the cleanser bulk affect friction properties. These findings assist in controlling the texture of body cleansers.
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Affiliation(s)
- Yoshimune Nonomura
- Department of Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University
| | - Mitsuki Omori
- Department of Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University
| | - Kei Kikuchi
- Department of Applied Chemistry, Chemical Engineering, and Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University
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9
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Šindelka K, Kowalski A, Cooke M, Mendoza C, Lísal M. Interactions of cationic surfactant-fatty alcohol monolayers with natural human hair surface: Insights from dissipative particle dynamics. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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10
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Fernandes C, Medronho B, Alves L, Rasteiro MG. On Hair Care Physicochemistry: From Structure and Degradation to Novel Biobased Conditioning Agents. Polymers (Basel) 2023; 15:polym15030608. [PMID: 36771909 PMCID: PMC9921463 DOI: 10.3390/polym15030608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Hair is constantly exposed to various adverse external stimuli, such as mechanical or thermal factors, that may cause damage or cause it to lose its shine and smooth appearance. These undesirable effects can be minimized by using hair conditioners, which repair the hair and restore the smooth effect desired by the consumer. Some of the currently used conditioning agents present low biodegradability and high toxicity to aquatic organisms. Consumers are also becoming more aware of environmental issues and shifting their preferences toward natural-based products. Therefore, developing novel, sustainable, natural-based derivatives that can act as conditioning agents in hair care products and thus compete with the traditional systems obtained from non-renewable sources is highly appealing. This paper presents the key physicochemical aspects of the hair conditioning process, including hair structure and degradation, and reviews some of the new alternative conditioning agents obtained from natural resources.
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Affiliation(s)
- Catarina Fernandes
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, R. Sílvio Lima, 3030-790 Coimbra, Portugal
- MED–Mediterranean Institute for Agriculture, Environment and Development, Universidade do Algarve, Faculdade de Ciências e Tecnologia, Campus de Gambelas, Ed. 8, 8005-139 Faro, Portugal
- Correspondence: (C.F.); (M.G.R.)
| | - Bruno Medronho
- MED–Mediterranean Institute for Agriculture, Environment and Development, Universidade do Algarve, Faculdade de Ciências e Tecnologia, Campus de Gambelas, Ed. 8, 8005-139 Faro, Portugal
- FSCN, Surface and Colloid Engineering, Mid Sweden University, SE-851 70 Sundsvall, Sweden
| | - Luís Alves
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, R. Sílvio Lima, 3030-790 Coimbra, Portugal
| | - Maria Graça Rasteiro
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, R. Sílvio Lima, 3030-790 Coimbra, Portugal
- Correspondence: (C.F.); (M.G.R.)
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11
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Coscia BJ, Shelley JC, Browning AR, Sanders JM, Chaudret R, Rozot R, Léonforte F, Halls MD, Luengo GS. Shearing friction behaviour of synthetic polymers compared to a functionalized polysaccharide on biomimetic surfaces: models for the prediction of performance of eco-designed formulations. Phys Chem Chem Phys 2023; 25:1768-1780. [PMID: 36597804 DOI: 10.1039/d2cp05465e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The substitution of natural, bio-based and/or biodegradable polymers for those of petrochemical origin in consumer formulations has become an active area of research and development as the sourcing and destiny of material components becomes a more critical factor in product design. These polymers often differ from their petroleum-based counterparts in topology, raw material composition and solution behaviour. Effective and efficient reformulation that maintains comparable cosmetic performance to existing products requires a deep understanding of the differences in frictional behaviour between polymers as a function of their molecular structure. In this work, we simulate the tribological behaviour of three topologically distinct polymers in solution with surfactants and in contact with hair-biomimetic patterned surfaces. We compare a generic functionalized polysaccharide to two performant polymers used in shampoo formulations: a strongly positively charged polyelectrolyte and a zwitterionic copolymer. Topological differences are expected to affect rheological properties, as well as their direct interaction with structured biological substrates. Using a refined Martini-style coarse-grained model we describe the polymer-dependent differences in aggregation behaviour as well as selective interactions with a biomimetic model hair surface. Additionally, we introduce a formalism to characterize the response of the solution to shear as an initial study on lubrication properties, which define the sensorial performance of these systems in cosmetics (i.e., manageability, touch, etc.). The tools and techniques presented in this work illustrate the strength of molecular simulation in eco-design of formulation as a complement to experiment. These efforts help advance our understanding of how we can relate complex atomic-scale solution behaviour to relevant macroscopic properties. We expect these techniques to play an increasingly important role in advancing strategies for green polymer formulation design by providing an understanding for how new polymers could reach and even exceed the level of performance of existing polymers.
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Affiliation(s)
| | | | | | | | | | - Roger Rozot
- L'Oréal Research and Innovation, Aulnay-Sous Bois, France.
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12
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Ritacco HA. Polyelectrolyte/Surfactant Mixtures: A Pathway to Smart Foams. ACS OMEGA 2022; 7:36117-36136. [PMID: 36278099 PMCID: PMC9583308 DOI: 10.1021/acsomega.2c05739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 09/26/2022] [Indexed: 05/10/2023]
Abstract
This review deals with liquid foams stabilized by polyelectrolyte/surfactant (PS) complexes in aqueous solution. It briefly reviews all the important aspects of foam physics at several scales, from interfaces to macroscopic foams, needed to understand the basics of these complex systems, focusing on those particular aspects of foams stabilized by PS mixtures. The final section includes a few examples of smart foams based on PS complexes that have been reported recently in the literature. These PS complexes open an opportunity to develop new intelligent dispersed materials with potential in many fields, such as oil industry, environmental remediation, and pharmaceutical industry, among others. However, there is much work to be done to understand the mechanism involved in the stabilization of foams with PS complexes. Understanding those underlying mechanisms is vital to successfully formulate smart systems. This review is written in the hope of stimulating further work in the physics of PS foams and, particularly, in the search for responsive foams based on polymer-surfactant mixtures.
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13
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Montes-de-Oca LM, Medina-Esquivel R, Zambrano-Arjona M, Martínez-Torres P. Thermal detection of second critical micelle concentration in SDS and CTAB aqueous solutions using a modified Lewis-Nielsen effective thermal model. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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14
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Chitosan: A Promising Multifunctional Cosmetic Ingredient for Skin and Hair Care. COSMETICS 2022. [DOI: 10.3390/cosmetics9050099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The cosmetic industry has an undeniable need to design and develop new ecosustainable products to respond to the demands of consumers and international regulations. This requires substituting some traditional ingredients derived from petrochemical sources with new ones with more ecofriendly profiles. However, this transition towards the use of green ingredients in the cosmetic industry cannot compromise the effectiveness of the obtained products. Emerging ingredients in this new direction of the cosmetic industry are chitosan and its derivatives, which combine many interesting physicochemical and biological properties for the fabrication of cosmetic products. Thus, the use of chitosan opens a promising future path to the design of cosmetic formulations. In particular, chitosan’s ability for interacting electrostatically with negatively charged substrates (e.g., skin or damaged hair), resulting in the formation of polymeric films which contribute to the conditioning and moisturizing of cosmetic substrates, makes this polymer an excellent candidate for the design of skin and hair care formulations. This review tries to provide an updated perspective on the potential interest of chitosan and its derivatives as ingredients of cosmetics for skin and hair care.
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15
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A Sebum-Mimetic Lipid Monolayer and Its Interaction with (Bio)Surfactants. COLLOIDS AND INTERFACES 2022. [DOI: 10.3390/colloids6020037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Surfactants present in cleansing formulations interact not only with the unwanted lipids accumulating on the human skin (dirt) but also with its protective lipidic layer (sebum). Development of simple models of human sebum would help to compare different surfactants and biosurfactants under the same conditions. In this contribution we propose a first monolayer model of synthetic sebum composed of lard, stearic acid, lanolin, squalane and cholesterol. The monolayer compression isotherm features a gas-liquid (G-LE1), two liquid-liquid transitions (LE1-LE2 and LE2-LC), and a collapse at πcoll = 45 mN/m. The monolayer spread on pure water and pre-compressed to π0 = 30 mN/m was exposed to four synthetic surfactants (sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES), ammonium lauryl sulfate (ALS) and cocamidopropyl betaine (CAPB)) and four plant extracts (oat (Avena sativa L.), horse chestnut (Aesculus hippocastanum L.), cowherb (Vaccaria hispanica [P. Mill.] Rauschert), soybean (Glycine max L.) and soapwort (Saponaria officinalis L.)) introduced to the subphase at a dry mass content of 1% (w/w). Three modes of the monolayer-(bio)surfactant interactions were observed: (1) complete solubilization (SLS, SLES, ALS, CAPB); (2) penetration accompanied by an increase of surface pressure and elasticity but without solubilization (horse chestnut, cowherb, soapwort); (3) no interaction (oat, soybean).
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16
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Pan A, Phani Kumar BV, Mati SS, Mal A, Prameela GK, Aswal VK, Moulik SP. Condition dependent self-aggregation behavior of aerosol-OT in mixed water-alcohol media: Physicochemical investigation. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Weiand E, Ewen JP, Koenig PH, Roiter Y, Page SH, Angioletti-Uberti S, Dini D. Coarse-grained molecular models of the surface of hair. SOFT MATTER 2022; 18:1779-1792. [PMID: 35112700 DOI: 10.1039/d1sm01720a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We present a coarse-grained molecular model of the surface of human hair, which consists of a supported lipid monolayer, in the MARTINI framework. Using coarse-grained molecular dynamics (MD) simulations, we identify a lipid grafting distance that yields a monolayer thickness consistent with both atomistic MD simulations and experimental measurements of the hair surface. Coarse-grained models for fully-functionalised, partially damaged, and fully damaged hair surfaces are created by randomly replacing neutral thioesters with anionic sulfonate groups. This mimics the progressive removal of fatty acids from the hair surface by bleaching and leads to chemically heterogeneous surfaces. Using molecular dynamics (MD) simulations, we study the island structures formed by the lipid monolayers at different degrees of damage in vacuum and in the presence of polar (water) and non-polar (n-hexadecane) solvents. We also use MD simulations to compare the wetting behaviour of water and n-hexadecane droplets on the model surfaces through contact angle measurements, which are compared to experiments using virgin and bleached hair. The model surfaces capture the experimentally-observed transition of the hair surface from hydrophobic (and oleophilic) to hydrophilic (and oleophobic) as the level of bleaching damage increases. By selecting surfaces with specific damage ratios, we obtain contact angles from the MD simulations that are in good agreement with experiments for both solvents on virgin and bleached human hairs. To negate the possible effects of microscale curvature and roughness of real hairs on wetting, we also conduct additional experiments using biomimetic surfaces that are co-functionalised with fatty acids and sulfonate groups. In both the MD simulations and experiments, the cosine of the water contact angle increases linearly with the sulfonate group surface coverage with a similar slope. We expect that the proposed systems will be useful for future molecular dynamics simulations of the adsorption and tribological behaviour of hair, as well as other chemically heterogeneous surfaces.
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Affiliation(s)
- Erik Weiand
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - James P Ewen
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - Peter H Koenig
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Cincinnati, 45224 Ohio, USA
| | - Yuri Roiter
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Cincinnati, 45224 Ohio, USA
| | - Steven H Page
- Corporate Functions Analytical and Data & Modeling Sciences, Mason Business Center, The Procter and Gamble Company, Cincinnati, 45224 Ohio, USA
| | - Stefano Angioletti-Uberti
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Department of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
| | - Daniele Dini
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, SW7 2AZ London, UK
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18
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Metilli L, Storm M, Marathe S, Lazidis A, Marty-Terrade S, Simone E. Application of X-ray Microcomputed Tomography for the Static and Dynamic Characterization of the Microstructure of Oleofoams. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:1638-1650. [PMID: 35050635 PMCID: PMC8812118 DOI: 10.1021/acs.langmuir.1c03318] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Oleofoams are a novel, versatile, and biocompatible soft material that finds application in drug, cosmetic or nutraceuticals delivery. However, due to their temperature-sensitive and opaque nature, the characterization of oleofoams' microstructure is challenging. Here, synchrotron X-ray microcomputed tomography and radiography are applied to study the microstructure of a triglyceride-based oleofoam. These techniques enable non-destructive, quantitative, 3D measurements of native samples to determine the thermodynamic and kinetic behavior of oleofoams at different stages of their life cycle. During processing, a constant bubble size distribution is reached after few minutes of shearing, while the number of bubbles incorporated keeps increasing until saturation of the continuous phase. Low amounts of solid triglycerides in oleofoams allow faster aeration and a more homogeneous microstructure but lower thermodynamic stability, with bubble disproportionation and shape relaxation over time. Radiography shows that heating causes Ostwald ripening and coalescence of bubbles, with an increase of their diameter and sphericity.
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Affiliation(s)
- Lorenzo Metilli
- School
of Food Science and Nutrition, Food Colloids and Bioprocessing group, University of Leeds, Woodhouse Lane, Leeds LS29JT, U.K.
| | - Malte Storm
- Diamond
Light Source Ltd., Harwell Science and Innovation
Campus, Didcot OX110DE, U.K.
- Helmholtz-Zentrum
hereon, Max-Planck-Str 1, 21502 Geesthacht, Germany
| | - Shashidhara Marathe
- Diamond
Light Source Ltd., Harwell Science and Innovation
Campus, Didcot OX110DE, U.K.
| | - Aris Lazidis
- Nestlé
Product Technology Centre Confectionery, Haxby Road, York YO31 8TA, U.K.
| | | | - Elena Simone
- School
of Food Science and Nutrition, Food Colloids and Bioprocessing group, University of Leeds, Woodhouse Lane, Leeds LS29JT, U.K.
- Department
of Applied Science and Technology (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino 10129, Italy
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19
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Abstract
The current consumer demands together with the international regulations have pushed the cosmetic industry to seek new active ingredients from natural renewable sources for manufacturing more eco-sustainability and safe products, with botanical extract being an almost unlimited source of these new actives. Essential oils (EOs) emerge as very common natural ingredients in cosmetics and toiletries as a result of both their odorous character for the design and manufacturing of fragrances and perfumes, and the many beneficial properties of their individual components (EOCs), e.g., anti-inflammatory, antimicrobial and antioxidant properties, and, nowadays, the cosmetic industry includes EOs or different mixtures of their individual components (EOCs), either as active ingredients or as preservatives, in various product ranges (e.g., moisturizers, lotions and cleanser in skin care cosmetics; conditioners, masks or antidandruff products in hair care products; lipsticks, or fragrances in perfumery). However, the unique chemical profile of each individual essential oil is associated with different benefits, and hence it is difficult to generalize their potential applications in cosmetics and toiletries, which often require the effort of formulators in seeking suitable mixtures of EOs or EOCs for obtaining specific benefits in the final products. This work presents an updated review of the available literature related to the most recent advances in the application of EOs and EOCs in the manufacturing of cosmetic products. Furthermore, some specific aspects related to the safety of EOs and EOCs in cosmetics will be discussed. It is expected that the information contained in this comprehensive review can be exploited by formulators in the design and optimization of cosmetic formulations containing botanical extracts.
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20
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Li J, Zhang J, Chen L, Zhang G, Liao J. Surface Properties and Liquid Crystal Properties of Alkyltetra(oxyethyl) β-d-Glucopyranoside. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:10617-10629. [PMID: 34473514 DOI: 10.1021/acs.jafc.1c03630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Hydrophilic alkyl polyglycosides (APGs) and alkyl glycosides (AGs) with anomeric pure are a class of important substitutes for petroleum-based surfactants. Improving their water solubility should make such hydrophilic glycosurfactants have more excellent potential application value. To solve the inherent problem of poor water solubility of traditional alkyl β-d-glucopyranoside (5), a series of alkyltetra(oxyethyl) β-d-glucopyranosides (4a-4g, n = 7-18) were successfully synthesized by introducing tetra(oxyethylene) fragments to carry out the structural modification. The relationship between the related structure and the physicochemical properties was further investigated, including their hydrophilic-lipophilic balance (HLB), water-solubility, foaming performance, emulsification, hygroscopicity, surface activity, and thermotropic/lyotropic liquid crystal phase behavior. The results showed that the water solubility gradually decreased as the alkyl chain length increased due to the gradual decrease of their HLB number. Octadecyltetra(oxyethyl) β-d-glucopyranoside (4g, n = 18) was found to be insoluble in water at 25 °C. Taken together, long-chain alkyl glycosides had good foaming properties and excellent emulsifying properties. Among them, dodecyltetra(oxyethyl) β-d-glucopyranoside (4d, n = 12) had the best foaming performance. In the rapeseed oil/water system, cetyltetra(oxyethyl) β-d-glucopyranoside (4f, n = 16) had the best emulsifying ability. With the increase of the alkyl chain length, the critical micelle concentration (Ccmc), γcmc, Γmax, and hygroscopicity of this series of glycosides showed a downward trend. Differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) showed that the thermal stability increased with the increase of the alkyl chain length, and alkyltetra(oxyethyl) β-d-glucopyranosides (4d-4g, n = 12-18) had the corresponding melting points and clearing points. Alkyltetra(oxyethyl) β-d-glucopyranosides (4b-4g, n = 8-18) formed a smectic phase with a typical fan-shaped and focal conic texture during the cooling process. In the water contact experiments, it was found that glycosides (4b-4g, n = 8-18) at high concentrations transformed into various lyotropic liquid crystal including hexagonal phase, bicontinuous cubic phase, and lamellar phase phases. Therefore, such green nonionic glycosurfactants alkyltetra(oxyethyl) β-d-glucopyranosides should have potential practical application prospects.
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Affiliation(s)
- Jiping Li
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Jing Zhang
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Langqiu Chen
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Guochao Zhang
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
| | - Jingyi Liao
- Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, People's Republic of China
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21
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Ludwig M, Geisler R, Prévost S, von Klitzing R. Shape and Structure Formation of Mixed Nonionic-Anionic Surfactant Micelles. Molecules 2021; 26:molecules26144136. [PMID: 34299413 PMCID: PMC8307929 DOI: 10.3390/molecules26144136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/29/2021] [Accepted: 07/03/2021] [Indexed: 11/16/2022] Open
Abstract
Aqueous solutions of a nonionic surfactant (either Tween20 or BrijL23) and an anionic surfactant (sodium dodecyl sulfate, SDS) are investigated, using small-angle neutron scattering (SANS). SANS spectra are analysed by using a core-shell model to describe the form factor of self-assembled surfactant micelles; the intermicellar interactions are modelled by using a hard-sphere Percus–Yevick (HS-PY) or a rescaled mean spherical approximation (RMSA) structure factor. Choosing these specific nonionic surfactants allows for comparison of the effect of branched (Tween20) and linear (BrijL23) surfactant headgroups, both constituted of poly-ethylene oxide (PEO) groups. The nonionic–anionic surfactant mixtures are studied at various concentrations up to highly concentrated samples (ϕ ≲ 0.45) and various mixing ratios, from pure nonionic to pure anionic surfactant solutions. The scattering data reveal the formation of mixed micelles already at concentrations below the critical micelle concentration of SDS. At higher volume fractions, excluded volume effects dominate the intermicellar structuring, even for charged micelles. In consequence, at high volume fractions, the intermicellar structuring is the same for charged and uncharged micelles. At all mixing ratios, almost spherical mixed micelles form. This offers the opportunity to create a system of colloidal particles with a variable surface charge. This excludes only roughly equimolar mixing ratios (X≈ 0.4–0.6) at which the micelles significantly increase in size and ellipticity due to specific sulfate–EO interactions.
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Affiliation(s)
- Michael Ludwig
- Soft Matter at Interfaces, Institute for Condensed Matter Physics, Technical University of Darmstadt, D-64289 Darmstadt, Germany; (M.L.); (R.G.)
| | - Ramsia Geisler
- Soft Matter at Interfaces, Institute for Condensed Matter Physics, Technical University of Darmstadt, D-64289 Darmstadt, Germany; (M.L.); (R.G.)
| | - Sylvain Prévost
- Large Scale Structures Group, DS/LSS, Institut Laue-Langevin, CEDEX 9, 38042 Grenoble, France;
| | - Regine von Klitzing
- Soft Matter at Interfaces, Institute for Condensed Matter Physics, Technical University of Darmstadt, D-64289 Darmstadt, Germany; (M.L.); (R.G.)
- Correspondence:
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