Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Phase transitions in non-ionic detergent micelles


Grell,  Ernst
Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Max Planck Society;


Lewitzki,  Erwin
Department of Molecular Neurogenetics, Max Planck Institute of Biophysics, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Grell, E., Lewitzki, E., Schneider, R., Ilgenfritz, G., Grillo, I., & von Raumer, M. (2002). Phase transitions in non-ionic detergent micelles. Journal of Thermal Analysis and Calorimetry, 68(2), 469-478. doi:10.1023/A:1016083501500.

Cite as: https://hdl.handle.net/11858/00-001M-0000-0024-DC2E-6
Differential scanning calorimetry (DSC) studies of micellar, 60 mM solutions of the octaethyleneglycol alkylethers C14E8 and C16E8 provide evidence for a narrow endothermic transition at 41 and 32°C, respectively, characterized by an enthalpy change of 2 kJ mol-1 for both detergents. The observed thermal transition is indicative of a concerted transition of the surfactant molecules, as illustrated on the basis of a simple molecular model. The effect of co-solvents such as different alcohols on the thermal transition is investigated. Glycerol markedly lowers the transition temperature whereas the transition is absent in the presence of at least 10% ethanol. The calorimetric transition correlates with the temperature dependent increase of viscosity and static light scattering as well as with changes observed by small-angle neutron scattering (SANS). The SANS results provide clear evidence for a distinct structural change occurring at the transition temperature, which is interpreted as a sphere-to-rod transition of the detergent micelles. Moreover, the rod length increases with increasing temperature. We suggest that the process causing the thermal transition acts as the prerequisite of the growth process.