TU Darmstadt / ULB / TUbiblio

Micellar interactions in water-AOT based droplet microemulsions containing hydrophilic and amphiphilic polymers

Appel, M. and Spehr, T. and Wipf, R. and Moers, C. and Frey, H. and Stühn, B. (2013):
Micellar interactions in water-AOT based droplet microemulsions containing hydrophilic and amphiphilic polymers.
In: The Journal of Chemical Physics, 139, (18), [Online-Edition: http://scitation.aip.org/content/aip/journal/jcp/139/18/10.1...],
[Article]

Abstract

We investigate the influence of addition of hydrophilic and amphiphilic polymer on percolation behavior and micellar interactions in AOT-based water-in-oil droplet microemulsions. We focus on two series of samples having constant molar water to surfactant ratio W = 20 and constant droplet volume fraction Φ = 30%, respectively. From dielectric spectroscopy experiments, we extract the bending rigidity of the surfactant shell by percolation temperature measurements. Depending on droplet size, we find stabilization and destabilization of the surfactant shell upon addition of hydrophilic poly(ethylene glycol) (PEG) (Mn = 3100 g mol−1) and amphiphilic poly(styrene)-b-poly(ethylene glycol) copolymer with comparable length of the hydrophilic block. Complementary small angle X-ray scattering experiments corroborate the finding of stabilization for smaller droplets and destabilization of larger droplets. Subsequent analysis of dielectric spectra enables us to extract detailed information about micellar interactions and clustering by evaluating the dielectric high frequency shell relaxation. We interpret the observed results as a possible modification of the inter-droplet charge transfer efficiency by addition of PEG polymer, while the amphiphilic polymer shows a comparable, but dampened effect.

Item Type: Article
Erschienen: 2013
Creators: Appel, M. and Spehr, T. and Wipf, R. and Moers, C. and Frey, H. and Stühn, B.
Title: Micellar interactions in water-AOT based droplet microemulsions containing hydrophilic and amphiphilic polymers
Language: English
Abstract:

We investigate the influence of addition of hydrophilic and amphiphilic polymer on percolation behavior and micellar interactions in AOT-based water-in-oil droplet microemulsions. We focus on two series of samples having constant molar water to surfactant ratio W = 20 and constant droplet volume fraction Φ = 30%, respectively. From dielectric spectroscopy experiments, we extract the bending rigidity of the surfactant shell by percolation temperature measurements. Depending on droplet size, we find stabilization and destabilization of the surfactant shell upon addition of hydrophilic poly(ethylene glycol) (PEG) (Mn = 3100 g mol−1) and amphiphilic poly(styrene)-b-poly(ethylene glycol) copolymer with comparable length of the hydrophilic block. Complementary small angle X-ray scattering experiments corroborate the finding of stabilization for smaller droplets and destabilization of larger droplets. Subsequent analysis of dielectric spectra enables us to extract detailed information about micellar interactions and clustering by evaluating the dielectric high frequency shell relaxation. We interpret the observed results as a possible modification of the inter-droplet charge transfer efficiency by addition of PEG polymer, while the amphiphilic polymer shows a comparable, but dampened effect.

Journal or Publication Title: The Journal of Chemical Physics
Volume: 139
Number: 18
Divisions: 05 Department of Physics
05 Department of Physics > Institute for condensed matter physics
Date Deposited: 06 Dec 2013 17:15
Official URL: http://scitation.aip.org/content/aip/journal/jcp/139/18/10.1...
Export:

Optionen (nur für Redakteure)

View Item View Item