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Competitive adsorption of a polydisperse polymer during emulsification: experiments and modeling
Lars Nilsson1, Mats Leeman, Karl-Gustav Wahlund
1Division of Food Technology, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00 Lund, Sweden. lars.nilsson@food.lth.se
Langmuir : the ACS Journal of Surfaces and Colloids
|January 31, 2007
Summary
High molar mass OSA-starch polymers selectively adsorb at the cyclohexane/water interface during emulsion formation. This selective adsorption is driven by turbulent flow, favoring larger polymer components.
Area of Science:
- Polymer Science
- Colloid and Interface Science
- Materials Science
Background:
- Understanding polymer adsorption at interfaces is crucial for emulsion stability and formulation.
- High molar mass polymers present unique challenges in characterization and adsorption behavior.
Purpose of the Study:
- To investigate the selective adsorption of OSA-starch, a high molar mass polymer, at the cyclohexane/water interface.
- To elucidate the mechanisms governing selective adsorption during emulsification.
Main Methods:
- Utilized Asymmetrical Flow Field-Flow Fractionation coupled with Multi-Angle Light Scattering and Refractive Index detection (AsFlFFF-MALS-RI) for polymer characterization.
- Analyzed the size and molar mass distribution of polydisperse ultrahigh molar mass polymers.
Main Results:
- Demonstrated selective adsorption of high molar mass components within the OSA-starch distribution.
- Identified convective mass transport in turbulent flow fields as the likely mechanism favoring adsorption of larger polymers.
- Observed rapid adsorption leading to potential nonequilibrium effects and interfacial jamming.
Conclusions:
- High molar mass polymers exhibit selective adsorption at the oil-water interface during emulsification.
- Turbulent flow dynamics play a significant role in the preferential transport of larger polymer chains to the interface.
- A turbulent flow collision model effectively illustrates the selective adsorption process.
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