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Rastogi P, Honecker D, Alba Venero D, Mahmoudi N, Kaisare NS, Basavaraj MG. Modulating shape transition in surfactant stabilized reverse microemulsions. SOFT MATTER 2023; 19:7033-7045. [PMID: 37681684 DOI: 10.1039/d3sm00682d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
The formation of reverse microemulsions (RMs) of spherical shape in the oil/water/surfactant ternary mixture at high molar ratio of water to surfactant (ω) is well established. Using dynamic light scattering, small-angle X-ray and neutron scattering, we elucidate the formation of non-spherical reverse microemulsions stabilised by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) at ω = 10 and volume fractions of the dispersed phase, Φ, ranging from 0.005 to 0.20. In addition, we propose a strategy to tune the aspect ratio of non-spherical droplets and colloidal interactions by (i) varying the volume fraction of the dispersed phase (ii) changing the temperature, and (iii) by substituting the aliphatic oil with a mixture of aliphatic and aromatic hydrocarbons. This tunability of anisotropy along with a precise control of the interactions in the RMs, their ability to form spontaneously and their thermodynamic stability is crucial to provide a handle on reaction kinetics, synthesis of anisotropic nanoparticles as well as for their application as lubricants and viscosity modifiers.
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Affiliation(s)
- Preetika Rastogi
- Department of Chemical Engineering, Indian Institute of Technology, Madras, Chennai - 600036, Tamil Nadu, India.
| | - Dirk Honecker
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Diego Alba Venero
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Najet Mahmoudi
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Niket S Kaisare
- Department of Chemical Engineering, Indian Institute of Technology, Madras, Chennai - 600036, Tamil Nadu, India.
| | - Madivala G Basavaraj
- Department of Chemical Engineering, Indian Institute of Technology, Madras, Chennai - 600036, Tamil Nadu, India.
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Promoting Efficacy and Environmental Safety of Pesticide Synergists via Non-Ionic Gemini Surfactants with Short Fluorocarbon Chains. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27196753. [PMID: 36235302 PMCID: PMC9572613 DOI: 10.3390/molecules27196753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/28/2022] [Accepted: 10/01/2022] [Indexed: 11/16/2022]
Abstract
Improving the utilization rate of pesticides is key to achieve a reduction and synergism, and adding appropriate surfactant to pesticide preparation is an effective way to improve pesticide utilization. Fluorinated surfactants have excellent surface activity, thermal and chemical stability, but long-chain linear perfluoroalkyl derivatives are highly toxic, obvious persistence and high bioaccumulation in the environment. Therefore, new strategies for designing fluorinated surfactants which combine excellent surface activity and environmental safety would be useful. In this study, four non-ionic gemini surfactants with short fluorocarbon chains were synthesized. The surface activities of the resulting surfactants were assessed on the basis of equilibrium surface tension, dynamic surface tension, and contact angle. Compared with their monomeric counterparts, the gemini surfactants had markedly lower critical micelle concentrations and higher diffusivities, as well as better wetting abilities. We selected a single-chain surfactant and a gemini surfactant with good surface activities as synergists for the glyphosate water agent. Both surfactants clearly improved the efficacy of the herbicide, but the gemini surfactant had a significantly greater effect than the single-chain surfactant. An acute toxicity test indicated that the gemini surfactant showed slight toxicity to rats.
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Gutierrez JA, Japas ML, Silber JJ, Falcone RD, Correa NM. Is it Necessary for the Use of Fluorinated Compounds to Formulate Reverse Micelles in a Supercritical Fluid? Searching the Best Cosurfactant to Create "Green" AOT Reverse Micelle Media. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:445-453. [PMID: 33373249 DOI: 10.1021/acs.langmuir.0c03093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Herein, we report the effect of employing two different alcohols, such as n-pentanol and 2,2,3,3,4,4,5,5-octafluoro pentanol (from now on F-pentanol), into 1,4-bis-2-ethylhexylsulfosuccinate (AOT) reverse micelles (RMs), to determine the interfacial activity and establish the best candidate to act as a cosurfactant in supercritical RMs. Dynamic light scattering (DLS), Fourier transform infrared (FT-IR), and fluorescence emission spectroscopy allowed us to determine and understand the behavior of alkanols in RMs. As a result, we found interesting displacements of alkanol molecules within the RMs, suggesting that the electrostatic interaction between SO3- and Na+ weakens because of new interactions of n-pentanol with SO3- through H-bonds, changing the curvature of the micellar interface. According to FT-IR and DLS studies, F-pentanol forms a RM polar core interacting through intermolecular H-bonds, suggesting no perturbations of the AOT RM interface. Hence, n-pentanol was selected as a cosurfactant to form supercritical RMs, which is confirmed by red edge excitation shift studies, using C343 as a molecular probe. Herein, we were able to create RMs under supercritical conditions without the presence of modified surfactants, fluorinated or multitailed compounds, which, to the best of our knowledge, was not shown before.
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Affiliation(s)
- Jorge A Gutierrez
- Programa de Seguridad y Salud en el Trabajo, Universidad del Quindío, Carrera 15 Calle 12 Norte, C.P. 630004 Armenia, Colombia
| | - M Laura Japas
- Gerencia Química, Centro Atómico Constituyentes-CNEA, AV. Gral. Paz 1499, Pcia, de Buenos Aires B1650KNA, San Martín, Argentina
| | - Juana J Silber
- Instituto para el Desarrollo Agroindustrial y de la Salud, IDAS, (CONICET-UNRC), Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P. X5804BYA Río Cuarto, Argentina
| | - R Darío Falcone
- Instituto para el Desarrollo Agroindustrial y de la Salud, IDAS, (CONICET-UNRC), Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P. X5804BYA Río Cuarto, Argentina
| | - N Mariano Correa
- Instituto para el Desarrollo Agroindustrial y de la Salud, IDAS, (CONICET-UNRC), Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P. X5804BYA Río Cuarto, Argentina
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Klovak V, Kulichenko S, Lelyushok S. Fluorescence Study of the Influence of the Structure and Hydrophobicity of Fluorescent Dyes and Cationic Surfactants on their Association in Aqueous Solutions. Aust J Chem 2021. [DOI: 10.1071/ch20221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The statistical characteristics of the dependences of the fluorescence signal of analytical systems as a function of the integral parameters of the structure of fluorescent reagents and cationic surfactants on their association in aqueous solutions has been investigated. Molecular weight, surface area, and their first-order molecular connectivity index have been taken as parameters of the structure of the reagents and cationic surfactants. The influence of the hydrophobicity of the reagent and cationic surfactants, such as the octanol–water distribution constant and octanol–water partition coefficient, on the fluorescence signal of the reagent–cationic surfactant associates have also been investigated. It is shown that the associates of anionic reagents with cationic surfactant counter ions are characterised by high stability and a higher analytical signal compared with associates in which there is no electrostatic attraction between the reagent and the surfactant ion. The effect of hydrophobicity of the reagent and cationic surfactant in the absence of electrostatic attraction between the interacting particles is similar. The increase in the role of the influence of the structure of cationic reagents in their association with cationic surfactants, when the electrostatic attraction is absent and the stability of the associates is due mainly to hydrophobic interactions, is noticeable. The regularities of the influence of the colloid-chemical state on the analytical signal of associated cationic surfactants in solutions have been investigated. The study made it possible to formulate a rational basis for the search and design of analytical systems for the determination of large cations by the fluorescence method.
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Sharma B, Thakur V, Kaur G, Chaudhary GR. Efficient Photodynamic Therapy against Gram-Positive and Gram-Negative Bacteria Using Rose Bengal Encapsulated in Metallocatanionic Vesicles in the Presence of Visible Light. ACS APPLIED BIO MATERIALS 2020; 3:8515-8524. [PMID: 35019621 DOI: 10.1021/acsabm.0c00901] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Significant consumption of antibiotics has generated multidrug resistance in bacteria, which is a major menace to human beings. Antibacterial photodynamic therapy (aPDT) is a progressing technique for inhibition of bacterial infection with minimal side effects. Metals and delivering agents play a major role in aPDT efficiency. Herein, we report a formulation to enrich the antibacterial photodynamic therapy utilizing metallocatanionic vesicles (MCVs) against both Gram-positive and Gram-negative bacteria. These MCVs were synthesized by utilizing iron-based double-chain metallosurfactant [FeCPC(II)] as a cationic surfactant and AOT, a double-chain anionic surfactant. These synthesized MCV fractions were characterized by distinct techniques like DLS, zeta potential, FE-SEM, confocal microscopy, SAXS, and UV-Visible spectroscopy. Polyhedral-shaped MCVs with a size of 200 nm were formed, wherein the charge and size of the catanionic vesicle can be controlled by varying the mixing ratios. Both Gram-positive bacteria, i.e., methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative bacteria, i.e., Escherichia coli (E. coli), were used for aPDT using Rose Bengal (RB) as a photosensitizer (PS) encapsulated in MCVs in the presence of a 532 nm wavelength laser. The aPDT against bacterial cells was evaluated for both dark and light toxicities. Pure MCVs also exhibited good antibacterial properties; however, much enhancement was observed in the presence of RB encapsulated in MCVs under light, where eradication of bacteria (E. coli and MRSA) was achieved in 30 min. The observations demonstrated that it is the presence of metal that enhances the singlet oxygen quantum yield of RB and MCVs help in retarding self-quenching and enhanced solubilization of RB. The cationic surfactant-rich fraction shows strong adhesion toward bacteria via electrostatic interactions. The outcome of this research shows that these newly fabricated metal-based metallocatanionic vesicles were effective against both Gram-positive and Gram-negative bacteria using aPDT and must be exploited for clinical applications as well as an alternative for antibiotics in the future.
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Affiliation(s)
- Bunty Sharma
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India
| | - Vipul Thakur
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India
| | - Gurpreet Kaur
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India
| | - Ganga Ram Chaudhary
- Department of Chemistry and Centre of Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India
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Legout P, Lefebvre G, Bonnin M, Gimel JC, Benyahia L, Colombani O, Calvignac B. Synthesis of PDMS- b-POEGMA Diblock Copolymers and Their Application for the Thermoresponsive Stabilization of Water-Supercritical Carbon Dioxide Emulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12922-12932. [PMID: 33076662 DOI: 10.1021/acs.langmuir.0c02194] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this study, PDMS13-b-POEGMAx diblock copolymers consisting of a CO2-philic poly(dimethylsiloxane) (PDMS) block connected to a thermosensitive hydrophilic poly(oligoethylene glycol methacrylate) (POEGMA) block were synthesized by reversible addition-fragmentation chain-transfer (RAFT) radical polymerization. Their ability to decrease the water-supercritical CO2 (scCO2) interfacial tension (γ) and to stabilize water-scCO2 emulsions was investigated using an original homemade device developed in the laboratory. This device is able to control the pressure from 1 to 250 bar and the temperature from 40 to 80 °C. It was implemented with 2 visualization windows, a drop tensiometer and a remote optical head for dynamic light scattering (DLS) measurements. These experiments revealed that PDMS-b-POEGMA decreased γ down to 1-2 mN/m and was the most efficient at high pressure (250 bar) and low temperature (40 °C) where PDMS and POEGMA blocks exhibited the highest affinity for their respective phase. The diblock copolymers were shown to stabilize water-scCO2 emulsions. Moreover, the thermosensitive behavior of the POEGMA block in water (with a lower critical solubility temperature around 65 °C) resulted in the formation of temperature-responsive emulsions that could reversibly switch at 100 bar from stable at 40 °C to unstable at 80 °C. These results were rationalized based on the solubility of each individual block of the copolymers in water and scCO2 as a function of temperature and pressure.
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Affiliation(s)
- Pierre Legout
- Micro et Nanomédecines Translationnelles, MINT, UNIV Angers, UMR INSERM 1066, UMR CNRS 6021, Angers, France
- Institut des Molécules et Matériaux du Mans (IMMM), UMR 6283 CNRS Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - Guillaume Lefebvre
- Micro et Nanomédecines Translationnelles, MINT, UNIV Angers, UMR INSERM 1066, UMR CNRS 6021, Angers, France
| | - Marie Bonnin
- Micro et Nanomédecines Translationnelles, MINT, UNIV Angers, UMR INSERM 1066, UMR CNRS 6021, Angers, France
| | - Jean-Christophe Gimel
- Micro et Nanomédecines Translationnelles, MINT, UNIV Angers, UMR INSERM 1066, UMR CNRS 6021, Angers, France
| | - Lazhar Benyahia
- Institut des Molécules et Matériaux du Mans (IMMM), UMR 6283 CNRS Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - Olivier Colombani
- Institut des Molécules et Matériaux du Mans (IMMM), UMR 6283 CNRS Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - Brice Calvignac
- Micro et Nanomédecines Translationnelles, MINT, UNIV Angers, UMR INSERM 1066, UMR CNRS 6021, Angers, France
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Sagisaka M, Saito T, Abe M, Yoshizawa A, Blesic M, Rogers SE, Alexander S, Guittard F, Hill C, Eastoe J. Water-in-CO 2 Microemulsions Stabilized by an Efficient Catanionic Surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:7418-7426. [PMID: 32532155 DOI: 10.1021/acs.langmuir.0c00970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To facilitate potential applications of water-in-supercritical CO2 microemulsions (W/CO2 μEs) efficient and environmentally responsible surfactants are required with low levels of fluorination. As well as being able to stabilize water-CO2 interfaces, these surfactants must also be economical, prevent bioaccumulation and strong adhesion, deactivation of enzymes, and be tolerant to high salt environments. Recently, an ion paired catanionic surfactant with environmentally acceptable fluorinated C6 tails was found to be very effective at stabilizing W/CO2 μEs with high water-to-surfactant molar ratios (W0) up to ∼50 (Sagisaka, M.; et al. Langmuir 2019, 35, 3445-3454). As the cationic and anionic constituent surfactants alone did not stabilize W/CO2 μEs, this was the first demonstration of surfactant synergistic effects in W/CO2 microemulsions. The aim of this new study is to understand the origin of these intriguing effects by detailed investigations of nanostructure in W/CO2 microemulsions using high-pressure small-angle neutron scattering (HP-SANS). These HP-SANS experiments have been used to determine the headgroup interfacial area and volume, aggregation number, and effective packing parameter (EPP). These SANS data suggest the effectiveness of this surfactant originates from increased EPP and decreased hydrophilic/CO2-philic balance, related to a reduced effective headgroup ionicity. This surfactant bears separate C6F13 tails and oppositely charged headgroups, and was found to have a EPP value similar to that of a double C4F9-tail anionic surfactant (4FG(EO)2), which was previously reported to be one of most efficient stabilizers for W/CO2 μEs (maximum W0 = 60-80). Catanionic surfactants based on this new design will be key for generating superefficient W/CO2 μEs with high stability and water solubilization.
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Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Tatsuya Saito
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Masashi Abe
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Marijana Blesic
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast BT7 1NN, U.K
| | - Sarah E Rogers
- ISIS-CCLRC, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, U.K
| | - Shirin Alexander
- Energy Safety Research Institute (ESRI), Swansea University, Bay Campus, Swansea SA1 8EN, U.K
| | - Frédéric Guittard
- NICE-Lab, Université Côte d'Azur, 61-63 avenue S. Viel, 06200 Nice, France
| | - Christopher Hill
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Julian Eastoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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Level G, Zhang J, Brown J, Hammond O, Hannigan B, Stella L, Nockemann P, Blesic M. Multicharge zwitterionic molecules: Hydration, kosmotropicity and anti-fouling potential. J Colloid Interface Sci 2020; 562:391-399. [DOI: 10.1016/j.jcis.2019.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/01/2019] [Accepted: 12/02/2019] [Indexed: 10/25/2022]
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Li X, Wang B, Dai S, Lu H, Huang Z. Ionic Liquid-Based Microemulsions with Reversible Microstructures Regulated by CO 2. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:264-272. [PMID: 31845812 DOI: 10.1021/acs.langmuir.9b03327] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
CO2-responsive microemulsions based on ionic liquid 1,1,3,3-tetramethylguanidine-oleic acid (TMG-OA) have been designed to provide an approach for reducing the volatilization of amine in amine-containing microemulsions effectively and exhibit reversible transitions of microstructures. The ionic liquid TMG-OA was prepared by the direct neutralization of oleic acid (HOA) and 1,1,3,3-tetramethylguanidine (TMG, one of volatile and toxic amines). From the investigations of nuclear magnetic resonance hydrogen spectrum, pH, thermogravimetry, and automatic interface tension meter, the excellent properties of switchability, stability, and surface activity of TMG-OA were demonstrated, and then the ionic liquid-based microemulsions with CO2 response were prepared with TMG-OA (surfactant), HOA (oil phase), isopropyl alcohol (IPA, cosurfactant), and water. Interestingly, for microemulsions with a higher IPA content (47.42, 44.48 wt %), sizes of microemulsions are increased upon introducing CO2 and decreased upon addition of N2/65 °C. In addition, for microemulsions with a lower IPA content (26.22 wt %), the new microemulsions with different sizes are regenerated after the phase separation of emulsions generated by introducing CO2, and incomplete recovery of microemulsions can be observed upon addition of N2/65 °C. The reversible microstructures are induced by the swelling behavior and the reduced single phase area, which are caused by the reversible conversion between TMG-OA and HOA components.
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Affiliation(s)
- Xiaojiang Li
- College of Chemistry and Chemical Engineering , Southwest Petroleum University , Chengdu 610500 , P. R. China
| | - Baogang Wang
- College of Chemistry and Chemical Engineering , Southwest Petroleum University , Chengdu 610500 , P. R. China
- Engineering Research Center of Oilfield Chemistry , Ministry of Education , Chengdu 610500 , P. R. China
| | - Shanshan Dai
- College of Chemistry and Chemical Engineering , Southwest Petroleum University , Chengdu 610500 , P. R. China
- Engineering Research Center of Oilfield Chemistry , Ministry of Education , Chengdu 610500 , P. R. China
| | - Hongsheng Lu
- College of Chemistry and Chemical Engineering , Southwest Petroleum University , Chengdu 610500 , P. R. China
- Engineering Research Center of Oilfield Chemistry , Ministry of Education , Chengdu 610500 , P. R. China
| | - Zhiyu Huang
- College of Chemistry and Chemical Engineering , Southwest Petroleum University , Chengdu 610500 , P. R. China
- Engineering Research Center of Oilfield Chemistry , Ministry of Education , Chengdu 610500 , P. R. China
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Sachin KM, Karpe SA, Singh M, Bhattarai A. Self-assembly of sodium dodecylsulfate and dodecyltrimethylammonium bromide mixed surfactants with dyes in aqueous mixtures. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181979. [PMID: 31032045 PMCID: PMC6458362 DOI: 10.1098/rsos.181979] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 03/01/2019] [Indexed: 05/20/2023]
Abstract
The micellar property of mixed surfactant systems, cationic (dodecyltrimethylammonium bromide, DTAB) and anionic (sodium dodecylsulfate, SDS) surfactants with variable molar ratios in aqueous system has been reported by using surface tension and conductivity measurements at T = 293.15, 298.15 and 303.15 K. DTAB concentrations are varied from 1.0 × 10-4 to 3 × 10-4 mol l-1 in 1.0 × 10-2 mol l-1 SDS solution while the SDS concentration is varied from 1.0 × 10-3 to 1.5 × 10-2 mol l-1 in approximately 5.0 × 10-3 mol l-1 DTAB, so that such concentrations of DTAB-SDS (DTAB-rich) and SDS-DTAB (SDS-rich) solutions were chosen 3 : 1 ratio. The critical micellar concentration, as well as surface and thermodynamic properties for DTAB-rich and SDS-rich solutions, were evaluated by the surface tension (γ) and conductivity (κ) methods. The pseudo phase separation model was coupled with the dissociated Margules model for synergism. The Krafft temperature behaviour and optical analysis of mixed surfactants are studied using conductivity and UV-Vis spectroscopy, respectively. The dispersibility and stability of DTAB-rich and SDS-rich solutions with and without dyes (2.5 × 10-5 mol l-1 of methyl orange and methylene blue) are carried out by using UV-Vis spectroscopy and dynamic light scattering.
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Affiliation(s)
- K. M. Sachin
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar, India
| | - Sameer A. Karpe
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar, India
| | - Man Singh
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar, India
| | - Ajaya Bhattarai
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar, India
- Department of Chemistry, Tribhuvan University, M. M. A. M. Campus, Biratnagar, Nepal
- Author for correspondence: Ajaya Bhattarai e-mail:
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