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Sun Q, Gong J, Sun Y, Song Y, Liu C, Xu B. The Spontaneous Vesicle-Micelle Transition in a Catanionic Surfactant System: A Chemical Trapping Study. Molecules 2023; 28:6062. [PMID: 37630313 PMCID: PMC10457922 DOI: 10.3390/molecules28166062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/10/2023] [Accepted: 08/12/2023] [Indexed: 08/27/2023] Open
Abstract
Typically, the formation of vesicles requires the addition of salts or other additives to surfactant micelles. However, in the case of catanionic surfactants, unilamellar vesicles can spontaneously form upon dilution of the micellar solutions. Our study explores the intriguing spontaneous vesicle-to-micelle transition in catanionic surfactant systems, specifically cetyltrimethyl ammonium bromide (CTAB) and sodium octylsulfonate (SOS). To gain insights into the changes occurring at the interface, we employ a chemical trapping method to characterize variations in the molarities of sulfonate headgroups, water, and bromide ions during the transition. Our findings reveal the formation of ion pairs between the cationic component of CTAB and the anionic component of SOS, leading to tight interfacial packing in CTAB/SOS solutions. This interfacial packing promotes vesicle formation at low surfactant concentrations. Due to the significant difference in critical micelle concentration (cmc) between CTAB and SOS, an increase in the stoichiometric surfactant concentration results in a substantial rise in the SOS-to-CTAB ratio within the interfacial region. This enrichment of SOS in the aggregates triggers the transition from vesicles to micelles. Overall, our study may shed new light on the design of morphologies in catanionic and other surfactant systems.
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Affiliation(s)
| | | | | | | | - Changyao Liu
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (Q.S.); (J.G.); (Y.S.); (Y.S.); (B.X.)
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Gong J, Yao K, Sun Q, Sun Y, Sun L, Liu C, Xu B, Tan J, Zhao L, Xu B. Interfacial Composition of Surfactant Aggregates in the Presence of Fragrance: A Chemical Trapping Study. Molecules 2022; 27:molecules27144333. [PMID: 35889205 PMCID: PMC9320350 DOI: 10.3390/molecules27144333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 12/02/2022] Open
Abstract
In recent years, there has been increasing interest in daily-use chemical products providing a pleasant scent. The added fragrance molecules may induce microstructural transitions of surfactant aggregates, which further affect the physical and chemical properties of the products. Here, the effects of four types of aromatic alcohols (cinnamyl alcohol, phenyl ethanol, phenyl methanol and anisyl alcohol) on cetyltrimethylammonium bromide (CTAB)/KBr aggregates were studied. The combined results from rheology, dynamic light scattering, and transmission electron microscopy measurements showed that cinnamyl alcohol induced significant micellar growth, while increases in micellar growth were less obvious for the other aromatic alcohols. The changes in the interfacial molarities of water, aromatic alcohol, and bromide ions during such transitions were studied using the chemical trapping method. Transitions resulting from added cinnamyl alcohol were accompanied by significant declines in interfacial water and bromide ion molarities, and a rise in interfacial alcohol molarity. The marked decrease in interfacial water molarity was not observed in previous studies of the octanol induced formation of wormlike micelles and vesicles, indicating that a different mechanism was presented in the current system. Nuclear magnetic resonance investigation showed that π–π stacking between cinnamyl alcohols, but not cation–π interactions between alcohols and CTAB headgroups, facilitated the tight packing of alcohol molecules in CTAB aggregates and the repulsion of water from the interfacial region. The current study may provide a theoretical basis for the morphological regulation of surfactant aggregates in the presence of additives.
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Affiliation(s)
- Jiani Gong
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
| | - Kaixin Yao
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
| | - Qihan Sun
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
| | - Yujia Sun
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
| | - Lijie Sun
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
| | - Changyao Liu
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
- Correspondence: (C.L.); (B.X.)
| | - Bo Xu
- McIntire School of Commerce, University of Virginia, Charlottesville, VA 22903, USA
- Correspondence: (C.L.); (B.X.)
| | - Jiajing Tan
- Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China;
| | - Li Zhao
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
| | - Baocai Xu
- Department of Daily Chemical Engineering, Beijing Technology and Business University, No. 11 Fucheng Road, Beijing 100048, China; (J.G.); (K.Y.); (Q.S.); (Y.S.); (L.S.); (L.Z.); (B.X.)
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