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Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
Anisotropic domain growth and complex coacervation in nanoclay-polyelectrolyte solutions
1Nanomaterials and Nanocomposites Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, India.
Advances in Colloid and Interface Science
|July 19, 2011
Summary
Complex coacervation driven by nanoclay and gelatin-A interactions was studied. Domains grew anisotropically, with equatorial growth following a power law and polar shrinkage, independent of quench depth.
Area of Science:
- Colloid and Surface Science
- Polymer Science
- Materials Science
Background:
- Complex coacervation is a liquid-liquid phase separation process crucial for developing advanced materials.
- Understanding the kinetics and mechanisms of domain growth in coacervating systems is essential for controlling material properties.
Purpose of the Study:
- To investigate the generalized domain growth dynamics in a coacervating solution composed of nanoclay (Laponite) and gelatin-A.
- To elucidate the role of associative electrostatic interactions in driving complex coacervation and phase separation.
Main Methods:
- Utilized depolarized dynamic light scattering to study phase separation kinetics below the spinodal temperature.
- Analyzed depolarization and axial ratio data to characterize domain growth and shape evolution.
Main Results:
- Observed time-dependent anisotropic growth of domains formed by soluble complexes.
- Equatorial axis growth followed a power law (a(t)~t^β, β=0.25 ± 0.04), while the polar axis shrunk (b(t)~t^-δ, δ=0.15 ± 0.05).
- Domains preferentially grew as oblate ellipsoids, with no observed effect of gravity on growth.
Conclusions:
- Demonstrated that associative electrostatic interactions between Laponite and gelatin-A drive complex coacervation at room temperature.
- Provided insights into the fundamental binding mechanisms between colloidal particles and polyelectrolytes.
- Characterized the phase separation kinetics and anisotropic domain growth in this coacervating system.
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