Abstract
The solution properties of dilute aqueous solutions of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers and their interaction with surfactants have been investigated using static and dynamic light scattering, combined with small angle X-ray scattering, calorimetry and nuclear magnetic resonance techniques.
In aqueous solution, the triblock copolymers P123 and F127 (EO20PO68EO20 and EO97PO68EO97, respectively) form micelles with a PPO core and a PEO corona. The triblock copolymer L121 (EO5PO68EO5) forms vesicles, that are quasi-stationary, by increasing the temperature into a two-phase region.
The P123 and the F127 micelles interact with a cationic (hexadecyltrimethylammonium chloride), an anionic (sodium dodecyl sulfate) and a nonionic [hexa(ethylene oxide) monododecyl ether] surfactant. The interaction behavior can be divided into three different surfactant concentration intervals. At low surfactant concentrations the copolymers and surfactants form a spherical mixed complex, which resembles a block copolymer micelle. In the ionic surfactant cases, the low surfactant concentration regime is followed by a narrow concentration interval, where two coexisting complexes (a large block copolymer micelle-surfactant complex and a small surfactant-copolymer complex) are found. At high ionic surfactant concentrations, the copolymer micelles are broken up due to the electrostatic interaction and only small surfactant-copolymer complexes are left. The surfactant-copolymer complex resembles a pure surfactant micelle. In the case of the nonionic surfactant, a single mixed complex is formed over the whole surfactant concentration range investigated. This complex undergoes a structural change and grows in one dimension into a rod-like complex at elevated temperatures (40 °C and above) and at high surfactant concentrations.
In aqueous solution, the triblock copolymers P123 and F127 (EO20PO68EO20 and EO97PO68EO97, respectively) form micelles with a PPO core and a PEO corona. The triblock copolymer L121 (EO5PO68EO5) forms vesicles, that are quasi-stationary, by increasing the temperature into a two-phase region.
The P123 and the F127 micelles interact with a cationic (hexadecyltrimethylammonium chloride), an anionic (sodium dodecyl sulfate) and a nonionic [hexa(ethylene oxide) monododecyl ether] surfactant. The interaction behavior can be divided into three different surfactant concentration intervals. At low surfactant concentrations the copolymers and surfactants form a spherical mixed complex, which resembles a block copolymer micelle. In the ionic surfactant cases, the low surfactant concentration regime is followed by a narrow concentration interval, where two coexisting complexes (a large block copolymer micelle-surfactant complex and a small surfactant-copolymer complex) are found. At high ionic surfactant concentrations, the copolymer micelles are broken up due to the electrostatic interaction and only small surfactant-copolymer complexes are left. The surfactant-copolymer complex resembles a pure surfactant micelle. In the case of the nonionic surfactant, a single mixed complex is formed over the whole surfactant concentration range investigated. This complex undergoes a structural change and grows in one dimension into a rod-like complex at elevated temperatures (40 °C and above) and at high surfactant concentrations.
| Original language | English |
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| Qualification | Doctor |
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| Award date | 2004 Oct 8 |
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| ISBN (Print) | 91-7422-049 |
| Publication status | Published - 2004 |
Bibliographical note
Defence detailsDate: 2004-10-08
Time: 10:15
Place: Lecture hall C, Center for Chemistry and Chemical Engineering, Lund
External reviewer(s)
Name: Schurtenberger, Peter
Title: Prof.
Affiliation: Université de Fribourg, Perolles, Switzerland
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Article: Paper IThe Interaction between PEO-PPO-PEO Triblock Copolymers and Ionic Surfactants in Aqueous Solution Studied Using Light Scattering and CalorimetryJansson, J.; Schillén, K.; Olofsson, G.; da Silva, R. C.; Loh, W.J. Phys. Chem. B 2004, 108, 82-92.
Article: Paper IIA Small Angle X-ray scattering, Light Scattering, and NMR study of PEO-PPO-PEO Triblock Copolymer/Cationic Surfactant Complexes in Aqueous SolutionJansson, J.; Schillén, K.; Nilsson, M.; Söderman, O.; Fritz, G.; Bergmann, A. and Glatter, O.Submitted to J. Phys. Chem. B
Article: Paper IIIDynamic and Static Light Scattering Studies of a PEO-PPO-PEO Triblock Copolymer/Nonionic Surfactant System in WaterJansson J.; Löf D.; Schillén K.; Costa T.Submitted to J. Phys. Chem. B
Article: Paper IVSpontaneous Vesicle Formation in a Block Copolymer SystemBryskhe, K.; Jansson, J.; Topgaard, D.; Schillén, K.; Olsson, U.J. Phys. Chem. B 2004, 108, 9710-9719.
Subject classification (UKÄ)
- Physical Chemistry (including Surface- and Colloid Chemistry)
Free keywords
- Polymer technology
- biopolymers
- Polymerteknik
- Physical chemistry
- Fysikalisk kemi
- Calorimetry
- SAXS
- DLS
- SLS
- Light scattering
- Structure
- Complex
- Block copolymer-surfactant interaction
- Block copolymer vesicles
- Self-assembly
- Triblock copolymers
- NMR