Abstract (EN):
In this work, the interaction between ethyl(hydroxyethyl) cellulose (EHEC) and three dimeric lysine-based surfactants of distinct chain length (C-6, C-8 and C-10) have been assessed and the system was evaluated in terms of its temperature-dependent gelling capacity. The viscosity profile depends on the specific surfactant, its concentration and temperature. The observed profiles reflected polymer-polymer associations at elevated temperatures and polymer-surfactant interactions, implying the formation of micellartype associations. The systems induce gelation at higher temperatures. Longer chain-length surfactants induce gelation at lower concentrations due to their stronger tendency to selfassemble. The thermo-responsive gels showed gel strength generally lower than 20 Pa.s(n) and a fractal dimension of 2.3-2.4, respectively, indicating the formation of soft gels comprising a tight and homogeneous network. The weakest gel was produced in the presence of the C-6 surfactant. 2D Small-Angle Light Scattering patterns showed a pronounced effect of temperature in terms of the evolution of large hydrophobic clusters, an event precluded when high concentrations of the longer chain surfactants were used.
Language:
English
Type (Professor's evaluation):
Scientific
Contact:
bo.nystrom@kjemi.uio.no
No. of pages:
10