This title appears in the Scientific Report :
2005
Please use the identifier:
http://hdl.handle.net/2128/1129 in citations.
Please use the identifier: http://dx.doi.org/10.1063/1.1857523 in citations.
Dynamic properties of microemulsions modified with homopolymers and diplock copolymers: The determination of bending moduli and renormalization effects
Dynamic properties of microemulsions modified with homopolymers and diplock copolymers: The determination of bending moduli and renormalization effects
The properties of bicontinuous microemulsions, consisting of water, oil, and a surfactant, can be modified by the addition of diblock copolymers (boosting effect) and homopolymers (inverse boosting effect) or a combination of both. Here, the influence of the addition of homopolymers (PEP(X) and PEO(...
Saved in:
Personal Name(s): | Holderer, O. |
---|---|
Frielinghaus, H. / Byelov, D. / Monkenbusch, M. / Allgaier, J. / Richter, D. | |
Contributing Institute: |
Neutronenstreuung; IFF-INS |
Published in: | The @journal of chemical physics, 122 (2005) S. 094908 |
Imprint: |
Melville, NY
American Institute of Physics
2005
|
Physical Description: |
094908 |
PubMed ID: |
15836182 |
DOI: |
10.1063/1.1857523 |
Document Type: |
Journal Article |
Research Program: |
Kondensierte Materie |
Series Title: |
Journal of Chemical Physics
122 |
Subject (ZB): | |
Link: |
Get full text OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1063/1.1857523 in citations.
The properties of bicontinuous microemulsions, consisting of water, oil, and a surfactant, can be modified by the addition of diblock copolymers (boosting effect) and homopolymers (inverse boosting effect) or a combination of both. Here, the influence of the addition of homopolymers (PEP(X) and PEO(X), X=5k or 10k molecular weight) on the dynamics of the surfactant layer is studied with neutron spin echo spectroscopy (NSE). Combining the results with the previous findings for diblock copolymers allows for a better separation of viscosity and bending modulus effects. With the addition of homopolymers, a significant increase of the relaxation rate compared to the pure microemulsion has been observed. The influence on the bending rigidity kappa is measured with NSE experiments. Homopolymer addition reduces kappa by up to Deltakappa approximately -0.5k(B)T, whereas the diblock copolymer yields an increase of kappa by approximately 0.3k(B)T. Comparison of the bending moduli that are obtained by analysis of the dynamics to those obtained from small angle neutron scattering (SANS) sheds light on the different renormalization length scales for NSE and SANS. Variation of the surfactant concentration at otherwise constant conditions of homopolymer or diblock-copolymer concentration shows that NSE results are leading to the pure bending rigidity, while the renormalized one is measured with SANS. |