Phase behaviour of <i>n</i>-alkyl- and bi-alkylbenzenesulphonates. Nematic lyotropics from double chain surfactants

Težak, Đurđica; Hertel, G.; Hoffmann, Hartmut

doi:10.1080/02678299108028225

Cited by 20 publications

(10 citation statements)

References 18 publications

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“…A multitude of phases [7,19] were observed in wide temperature and concentration ranges. Examination of the isotropic region showed the existence of spherical micelles (CMC NaD-BS = 2.70-3.12 mmol dm -3 ) [18][19][20], transformation to oblate micelles at 7.78 9 10 -3 mol dm -3 [24,25], and transition to vesicular dispersion at 8.30 9 10 -2 mol dm -3 at 303 K [24]. At this temperature, electrolyte addition to pure NaDBS (c NaDBS = 2.86 mmol dm -3 ) induces transition of isotropic micellar to an anisotropic lamellar solution at c NaCl [ 6.67 9 10 -2 mol dm -3 , and slightly increases the very low Krafft temperature in systems with c NaCl = 1 mol dm -3 [7].…”

Section: Resultsmentioning

confidence: 99%

Amphiphilic Properties of Dodecylammonium Chloride/4‐(1‐Pentylheptyl) Benzene Sodium Sulfonate Aqueous Mixtures and Study of the Catanionic Complex

Mihelj¹,

Tomašić²

2013

J Surfact & Detergents

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Surfactants are often used in supramolecular chemistry, due to their ability to self‐organize. Surfactant molecules aggregate spontaneously and reversibly to adopt a defined intermolecular arrangement. In this work, general phase behavior, adsorption and association in aqueous mixtures of dodecylammonium chloride, DACl and sodium 4‐(1‐pentylheptyl) benzenesulfonate, NaDBS, were studied by a combination of techniques including surface tension and conductivity measurements, light scattering and optical microscopy. The strong synergistic properties of the system were brought out with the Regular Solution Theory. Various colloidal objects are observed in wide range of composition: conventional small vesicles, large giant multilamellar or multivesicular vesicles. An excess of NaDBS provides extremely large tubular and elongated multilamellar vesicles. The new catanionic 1:1 complex, dodecylammonium‐4‐(1‐pentylheptyl) benzenesulfonate, formed in the equimolar conditions is a result of intramolecular charge neutralization. The thermal properties of this solid compound were examined by thermal polarizing microscopy, differential scanning calorimetry, and X‐ray diffraction. The most probable ion‐pair amphiphilic cluster of the crystal smectic phase, at room temperature, consists of ionic groups formed in ordered layers with dodecyl chains packed into somewhat disordered layers, tilted to the layer plane.

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Section: Resultsmentioning

confidence: 99%

Amphiphilic Properties of Dodecylammonium Chloride/4‐(1‐Pentylheptyl) Benzene Sodium Sulfonate Aqueous Mixtures and Study of the Catanionic Complex

Mihelj¹,

Tomašić²

2013

J Surfact & Detergents

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“…In recent years, the aggregation behavior of linear alkylbenzene Å 1%. sulfonate (LAS) isomers and their micelle structure have been investigated Sodium salt of commercial secondary alkyl sulfonate (ex: Hoechst, Gerby a variety of techniques, such as NMR spectroscopy (2)(3)(4), fluorescence many) was also analyzed by fast atom bombardment mass spectroscopy to spectroscopy (5-10), and small angle neutron scattering (11). In the deterdetermine its molecular weight and chain length distribution.…”

Section: Introductionmentioning

confidence: 99%

Determination of Critical Micelle Concentration of Anionic Surfactants: Comparison of Internal and External Fluorescent Probes

Goon¹,

Manohar

Kumar³

1997

Journal of Colloid and Interface Science

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“…In recent years, aggregation behavior of NaLAS has been extensively studied (1)(2)(3)(4)(5)(6). Spectroscopic studies done in our laboratory on these classes of surfactants indicated some interesting aggregation-induced conformational changes.…”

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confidence: 98%

Detergency and foam studies on linear alkylbenzene sulfonate and secondary alkyl sulfonate

Goon¹,

Bhirud

Kumar³

1999

J Surfact & Detergents

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Among anionic surfactants used in detergent products, the sodium salt of linear alkylbenzene sulfonate (NaLAS) is the only surfactant belonging to the aromatic class; the others are aliphatic, e.g., the sodium salt of secondary alkyl sulfonate (NaSAS). We observed earlier that certain conformational changes taking place in aromatic anionic surfactants (NaLAS) upon micellization can be brought about in aliphatic anionic surfactants (NaSAS) by addition of phenol. In this paper we examined how conformational changes at the molecular level translated into macroscopic properties such as foam and detergency. We performed foam and detergency measurements on NaLAS, NaSAS, and NaSAS/phenol systems. Foam behavior of these systems is shown to be dependent only upon calcium ion sensitivities of the surfactants whereas the detergency results have a dependence on conformational changes at the molecular level.Among anionic surfactants used in detergent products, the sodium salt of linear alkylbenzene sulfonate (NaLAS) is the only aromatic one; the others are aliphatic. In recent years, aggregation behavior of NaLAS has been extensively studied (1-6). Spectroscopic studies done in our laboratory on these classes of surfactants indicated some interesting aggregation-induced conformational changes. Specifically, in the case of NaLAS, the proton nuclear magnetic resonance (NMR) peaks corresponding to terminal methyl groups of the hydrocarbon chains appeared as a composite triplet below the critical micelle concentration (CMC). However, upon micellization, two well-defined triplets corresponding to each of the terminal methyl groups were observed. Based on these results, it was concluded that in NaLAS micelles, the shorter alkyl chain loops toward the palisade layer and experiences the phenyl ring effect (7). These conformational changes were not observed in the case of nonaromatic surfactants, specifically the sodium salt of secondary alkyl sulfonates/sulfates (NaSAS). However, the conformational changes encountered in NaLAS were brought about in NaSAS by the external incorporation of a phenyl ring by the addition of phenol (8). These phenomena indicate that the aggregation-induced conformation changes caused by the aromatic ring in NaLAS can be mimicked in the aliphatic anionic surfactant NaSAS by introducing a phenyl group externally.The objective of this paper was to examine how conformational changes observed at the molecular level translated into macroscopic properties. In view of this, the foam and detergency behavior of NaLAS, NaSAS, and NaSAS/phenol systems was studied. MATERIALS AND METHODSA sample of the sodium salt of LAS was prepared in the laboratory by neutralizing commercial linear alkylbenzene sulfonic acid (Reliance Industries, Mumbai, India) with sodium hydroxide solution in a Z-blade (Sigma) mixer. The resulting paste of NaLAS was dried in an oven at about 60°C, followed by vacuum drying. This dried NaLAS was subjected to Soxhlet solvent extraction using hexane to remove nondetergent organic matter. The paste was...

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Phase behaviour of n-alkyl- and bi-alkylbenzenesulphonates. Nematic lyotropics from double chain surfactants

Cited by 20 publications

References 18 publications

Amphiphilic Properties of Dodecylammonium Chloride/4‐(1‐Pentylheptyl) Benzene Sodium Sulfonate Aqueous Mixtures and Study of the Catanionic Complex

Amphiphilic Properties of Dodecylammonium Chloride/4‐(1‐Pentylheptyl) Benzene Sodium Sulfonate Aqueous Mixtures and Study of the Catanionic Complex

Determination of Critical Micelle Concentration of Anionic Surfactants: Comparison of Internal and External Fluorescent Probes

Detergency and foam studies on linear alkylbenzene sulfonate and secondary alkyl sulfonate

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