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Effect of interfacial tension on propagating polymerization fronts.
R. Texier-Picard1, J. A. Pojman, Vit. A. Volpert
1Analyse Numerique, Universite Lyon 1, UMR 5585 CNRS, 69622 Villeurbanne cedex, France.
Chaos (Woodbury, N.Y.)
|June 5, 2003
Summary
This study reveals a new instability mechanism in polymerization fronts. Chemical reactions decrease interfacial tension, driving liquid motion and creating a feedback loop that enhances instability.
Area of Science:
- Polymer Chemistry
- Fluid Dynamics
- Chemical Engineering
Background:
- Polymerization fronts convert monomers to polymers, with immiscible phases presenting stability challenges.
- Interfacial tension is a key factor in multiphase systems, but its role in reacting systems is complex.
Purpose of the Study:
- Investigate the influence of interfacial tension on polymerization front stability.
- Identify novel instability mechanisms beyond traditional Marangoni effects.
Main Methods:
- Mathematical modeling using reaction-diffusion and Navier-Stokes equations.
- Linear stability analysis incorporating interfacial tension jump conditions.
- Analysis of feedback mechanisms between reaction heat and interfacial tension.
Main Results:
- A novel instability mechanism driven by the interplay of chemical reaction and interfacial tension was identified.
- Heat generated by polymerization reduces interfacial tension, initiating convective fluid motion.
- This motion enhances monomer supply to the reaction zone, creating a positive feedback loop.
Conclusions:
- The interaction between exothermic polymerization and interfacial tension can destabilize polymerization fronts.
- A critical value of the frontal Marangoni number determines the onset of this reaction-driven instability.
- This finding has implications for controlling polymerization processes in immiscible systems.