Self-Assembly, Surface Activity and Structure of n-Octyl-β-D-thioglucopyranoside in Ethylene Glycol-Water Mixtures

International Journal of Molecular Sciences

Cristl Carnero Ruiz¹  José Antonio Molina-Bolívar²  José Manuel Hierrezuelo² 

[1] Department of Applied Physics II, Engineering School, University of Málaga, Málaga 29071, Spain;

关键词: n-octyl-β-d-thioglucopyranoside;    ethylene glycol;    surface tension;    light scattering;    time-resolved fluorescence anisotropy;   

DOI  :  10.3390/ijms14023228

来源: mdpi

【 摘 要 】

The effect of the addition of ethylene glycol (EG) on the interfacial adsorption and micellar properties of the alkylglucoside surfactant n-octyl-β-d-thioglucopyranoside (OTG) has been investigated. Critical micelle concentrations (cmc) upon EG addition were obtained by both surface tension measurements and the pyrene 1:3 ratio method. A systematic increase in the cmc induced by the presence of the co-solvent was observed. This behavior was attributed to a reduction in the cohesive energy of the mixed solvent with respect to pure water, which favors an increase in the solubility of the surfactant with EG content. Static light scattering measurements revealed a decrease in the mean aggregation number of the OTG micelles with EG addition. Moreover, dynamic light scattering data showed that the effect of the surfactant concentration on micellar size is also controlled by the content of the co-solvent in the system. Finally, the effect of EG addition on the microstructure of OTG micelles was investigated using the hydrophobic probe Coumarin 153 (C153). Time-resolved fluorescence anisotropy decay curves of the probe solubilized in micelles were analyzed using the two-step model. The results indicate a slight reduction of the average reorientation time of the probe molecule with increasing EG in the mixed solvent system, thereby suggesting a lesser compactness induced by the presence of the co-solvent.

【 授权许可】

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© 2013 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.