Interaction between Nonionic Micelles and a Nonionic Polymer Studied by Fourier Transform NMR Self-Diffusion

Abstract

The interaction between octaethylene glycol mono-n-dodecyl ether (C12Eg) and ethylhydroxyethyl cellulose (EHEC) in aqueous solution has been studied by measuring the C&g self-diffusion coefficient in the presence of EHEC at 25 OC. Micelle diffusion is influenced by the polymer in two ways, i.e. obstruction due to the polymer network and association of micelles to the polymer chains. It is demonstrated that, from studies using polymers of different polarity, a separation between obstruction and association effects can be achieved. It is found that the interaction between a relatively hydrophobic EHEC and the surfactant is dominated by a strong attraction leading to a formation of polymer-surfactant complexes. This observation is consistent with phase diagram findings. Taking into account the obstruction from both micelles and polymer chains, the binding isotherm of C&g to the hydrophobic EHEC is calculated by using a two-site model.

On the Thermal Gelling of Ethyl(hydroxyethyl)cellulose and Sodium Dodecyl Sulfate. Phase Behavior and Temperature Scanning Calorimetric Response

“…C 12 EO 8 has a cmc of 9 × 10 -5 mol kg -1 at 25 °C in water so in 4 mmol kg -1 solution it will predominantly be in the form of micelles. Zhang et al …”

“…C 12 EO 8 has a cmc of 9 × 10 -5 mol kg -1 at 25 °C in water so in 4 mmol kg -1 solution it will predominantly be in the form of micelles. Zhang et al 21 concluded from results of NMR self-diffusion measurements on the EHEC A-C 12 EO 8 system that there is an attractive interaction between C 12 EO 8 micelles and the polymer.…”

On the use of titration calorimetry to study the association of surfactants in aqueous solutions

“…This indicates that the polymer interacts preferably with micelles of OTG. The nonionic surfactant C 12 E 8 interacts in the form of micelles with ethylhydroxyethyl cellulose in aqueous solution 49 and other nonionic surfactants can be expected to interact in the same way as pseudo-polymers. We believe that if the polymer influences the aggregation of a surfactant that will lead to a lowering of the aggregation concentration c.a.c.…”

Surface Tension, Viscosity, and Refractive Index of Sodium Dodecyl Sulfate (SDS) in Aqueous Solution Containing Poly(ethylene glycol) (PEG), Poly(vinyl pyrrolidone) (PVP), and Their Blends

“…The micelle sizes are similar to and without polymer present, whereas aggregation numbers are similar or slightly lower than those of micelles forming in the absence of polymer. When a surfactant is added to an aqueous solution of polymer having hydrophobic segments, then due to a hydrophobic effect, it would become thermodynamically favorable for the surfactant to adsorb to polymer or even to form aggregates with a hydrophobic portion of the polymer. − …”