Sequence disorder-induced first order phase transition in confined polyelectrolytes

Area of Science:

• Statistical mechanics
• Polymer physics
• Physical chemistry

Background:

• Polyelectrolytes are polymers with charged monomers, exhibiting complex behavior due to electrostatic interactions.
• Understanding polyelectrolyte behavior is crucial in fields ranging from biology to materials science.
• Disorder in polymer sequences can significantly influence macroscopic properties.

Purpose of the Study:

• To investigate the statistical mechanical model of a flexible polyelectrolyte with quenched disorder.
• To analyze the free energy and monomer density profile in a confined system without electrolyte screening.
• To determine the impact of contour sequence disorder on polyelectrolyte localization and phase transitions.

Main Methods:

• Development of a statistical mechanical model for a flexible polyelectrolyte.
• Inclusion of long-range electrostatic interactions and short-range disorder fields.
• Calculation of free energy and monomer density for a system confined between two charged surfaces.

Main Results:

• Contour sequence disorder enhances polyelectrolyte chain localization.
• A first-order phase transition occurs at a critical inter-surface spacing.
• The phase transition causes an abrupt pressure change from negative to positive values.

Conclusions:

• Quenched disorder drives significant changes in polyelectrolyte behavior within confined geometries.
• The observed phase transition alters inter-surface forces, suppressing bridging attraction.
• This study provides insights into the role of disorder in polyelectrolyte systems.