Tail unsaturation tailors the thermodynamics and rheology of a self-assembled sugar-based surfactant

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:585

Article

Larsson, Johan¹  Leung, Anna E.²  Lang, Christian³  Wu, Baohu³  Wahlgren, Marie⁴  Nylander, Tommy^1,5  Ulvenlund, Stefan^4,6  Sanchez-Fernandez, Adrian⁴ 

[1] Dept Chem, Phys Chem, Box 124, S-22100 Lund, Sweden

[2] European Spallat Source, Box 176, S-22100 Lund, Sweden

[3] Forschungszentrum Julich, Heinz Maier Leibnitz Zentrum MLZ, Julich Ctr Neutron Sci JCNS, Lichtenbergstr 1, D-85748 Garching, Germany

[4] Food Technol Engn & Nutr, Box 124, S-22100 Lund, Sweden

[5] Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden

[6] EnzaBiotech AB, Scheelevagen 22, S-22363 Lund, Sweden

关键词: Unsaturated surfactant;    Sugar-based surfactant;    Worm-like micelle;    Viscoelastic fluid;    Small-angle scattering;   

DOI  :  10.1016/j.jcis.2020.11.063

来源: Elsevier

【 摘 要 】

Hypothesis: The self-assembly of long-tail surfactants results in the formation of nanoscale structures, e.g. worm-like micelles, with the ability to modify the rheology of the system. However, micelle formation, and thus the alteration of the rheology, is subject to the high Krafft temperature of saturated long-tail surfactants. Hexadecylmaltosides are sustainable surfactants that, in solution, form tailorable viscoelastic fluids. The preparation of monounsaturated sugar-based surfactants is hypothesised to reduce the Krafft point compared to the saturated analogues, therefore increasing the temperature range where the surfactant remains in the micellar form. Experiments: Here we report the synthesis and characterisation of a novel sugar-based surfactant with an unsaturated C16-tail, namely palmitoleyl-beta-D-maltoside (beta-C(16-1)G(2)). Differential scanning calorimetry was used to probe the temperature stability of the system. The rheology of beta-C(16-1)G(2) solutions was investigated by means of rotational and oscillatory rheology, and these results were connected to the mesoscopic structure of the system as shown by small-angle neutron and X-ray scattering, and dynamic light scattering. Findings: The presence of a double bond on the alkyl chain moiety leads to a depression in the Krafft point, allowing the surfactant to form a thermodynamically stable micellar solution over a wide range of temperatures, i.e. 5-95 degrees C. The surfactant self-assembles into worm-like micelles which, upon entanglement in the semi-dilute regime, result in the formation of a non-Newtonian, viscoelastic fluid. These observations have important implications in the development of new sustainable formulated products, enabling the preparation of surfactant phases with remarkable thermal resilience. (C) 2020 The Author(s). Published by Elsevier Inc.

【 授权许可】

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