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Molecular Entanglement and Electrospinnability of Biopolymers

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Published on: September 3, 2014

Viscosity-change-induced density fingering in polyelectrolytes.

Tamás Rica¹, Dezsö Horváth, Agota Tóth

¹Department of Physical Chemistry, University of Szeged, Szeged, Hungary.

The Journal of Physical Chemistry. B

|August 14, 2008

Summary

This summary is machine-generated.

Density fingering in an acid-catalyzed reaction with polyelectrolytes creates spatiotemporal patterns. Changes in polymer ionic character and viscosity driven by pH shifts are key to pattern formation.

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Area of Science:

Chemical kinetics
Polymer science
Fluid dynamics

Background:

Acid-catalyzed autocatalytic reactions exhibit complex dynamics.
Polyelectrolytes can significantly alter solution properties like viscosity.
pH changes can induce conformational and ionic character modifications in polyelectrolytes.

Purpose of the Study:

To investigate density fingering phenomena in an acid-catalyzed autocatalytic reaction.
To understand the role of carboxylate-containing polyelectrolytes in pattern formation.
To quantitatively characterize the evolution of reaction fronts.

Main Methods:

Experimental study of density fingering.
Utilizing an acid-catalyzed autocatalytic reaction system.
Incorporating carboxylate-containing polyelectrolytes.
Monitoring pH changes and viscosity variations.
Analysis of front evolution using dispersion curves.

Main Results:

Density fingering was observed, leading to spatiotemporal pattern formation.
A decrease in viscosity, driven by pH-induced changes in polymer ionic character, was identified as the primary driver.
The evolution of the reaction front was successfully characterized quantitatively.

Conclusions:

The interplay between reaction kinetics, polyelectrolyte properties, and fluid dynamics governs pattern formation.
Viscosity reduction due to pH-dependent polyelectrolyte behavior is crucial for density fingering.
Dispersion curves provide a valuable tool for analyzing reaction front dynamics.