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Non-equilibrium interaction between catalytic colloids: boundary conditions and penetration depth
Alexander Y Grosberg1, Yitzhak Rabin
1Department of Physics and Center for Soft Matter Research, New York University, 726 Broadway, New York, NY 10003, USA. ayg1@nyu.edu.
Soft Matter
|July 24, 2020
Summary
Catalytic colloids interact via solute concentration fields. Their catalytic activity suppresses long-range interactions, unlike electrostatic screening, with geometry-dependent effects observed in 3D and quasi-2D systems.
Area of Science:
- Colloid Science
- Chemical Physics
- Soft Matter Physics
Background:
- Colloids interacting via solute concentration fields can exhibit long-range forces.
- Non-equilibrium conditions are crucial for maintaining these concentration gradients and interactions.
Purpose of the Study:
- To investigate the interaction mechanisms between spherical colloids catalyzing a reversible reaction A ⇌ B.
- To understand how non-equilibrium boundary conditions and geometry affect these colloid-colloid interactions.
Main Methods:
- Theoretical analysis of solute concentration fields around catalytic colloids.
- Modeling of colloid-colloid interactions arising from these non-uniform concentration fields.
- Examination of system behavior in 3D bulk and quasi-2D confined geometries.
Main Results:
- Catalytic activity suppresses the long-range 1/r interaction, distinct from electrostatic screening.
- Suppression occurs as catalytic activity drives solute concentrations towards equilibrium.
- Long-range interactions persist in quasi-2D geometries, leading to cluster or Wigner crystal formation.
Conclusions:
- The interaction between catalytic colloids is modulated by their chemical activity and system geometry.
- Non-equilibrium effects can lead to novel self-assembly phenomena, particularly in reduced dimensions.
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