Philomène Le Bastart de Villeneuve

2025

1. Le Bastart de Villeneuve, P., Trummer, F., Preisig, N., Yalcinkaya, H., Venzmer, J., Kleinen, J., Sottmann, T., Stubenrauch, C.: Self-Assembly and Liquid Crystalline Phases of the Biosurfactant di-Rhamnolipid. Journal of Molecular Liquids. 436, 128271 (2025). https://doi.org/10.1016/j.molliq.2025.128271.
   • Abstract
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   Abstract

   The growing demand for sustainable surfactants has led to increased interest in biosurfactants such as rhamnolipids. We studied the self-assembly of the biosurfactant di-rhamnolipid (Image 1) in Image 2 starting at the cmc up to the Lyotropic Liquid Crystal (LLC) regime. Measuring the phase behaviour at two different pH values, 6.0 () and 8.0 (), one sees how the charge of the surfactant influences the properties. At a , Image 3 behaves similar to nonionic alkyl polyglucoside surfactants, and forms micelles over a large concentration range and a lamellar phase at high concentrations. In contrast, at a the surfactant's carboxyl group is deprotonated, leading to ionic behaviour and the formation of globular micelles at low concentrations and a hexagonal phase at higher concentrations. The transition between the micellar and the phase occurs over a narrow concentration range, suggesting a sharp structural reorganisation. Our findings highlight the strong influence of the pH on the self-assembly of di-rhamnolipid over a broad concentration range.

   Link

   http://dx.doi.org/10.1016/j.molliq.2025.128271