How to control a polymer conformation using active forces and sequence design

Area of Science:

• Polymer Physics
• Materials Science
• Soft Matter Physics

Background:

• Active polymers possess monomer units that convert external energy into directed motion.
• This intrinsic activity drives self-ordering in polymers, creating nonequilibrium states.
• Such polymers are crucial for understanding biological systems and developing novel synthetic materials.

Purpose of the Study:

• Investigate the conformational behavior of active copolymers with varying distributions of active and passive units.
• Determine the impact of active unit fraction and block length on copolymer structure.
• Assess the universality of observed phenomena across different activity models.

Main Methods:

• Utilized molecular dynamics simulations to model copolymer behavior.
• Analyzed conformational changes in response to varying fractions of active beads.
• Examined the influence of repeating block lengths on polymer structure.

Main Results:

• Even a small fraction of active beads induces polymer collapse.
• The fraction of active units significantly influences conformational characteristics.
• The length of repeating blocks affects the overall structure of active copolymers.
• Observed phenomena are qualitatively independent of the specific activity model employed.

Conclusions:

• Active copolymers exhibit unique nonequilibrium self-ordering and collapse behaviors.
• A minimal presence of active units is sufficient to drive significant conformational changes.
• The findings suggest universal principles governing the behavior of active polymers, applicable to both biological and synthetic systems.