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Universal negative energetic elasticity in polymer chains: Crossovers among random, self-avoiding, and
Nobu C Shirai1, Naoyuki Sakumichi2,3
1Mie University, Center for Information Technologies and Networks, Tsu, Mie 514-8507, Japan.
Physical Review. E
|September 16, 2025
Summary
Negative energetic elasticity in polymer chains, a phenomenon challenging conventional understanding, arises from effective soft-repulsive interactions. This study reveals its fundamental nature in polymer networks and chains.
Area of Science:
- Polymer Physics
- Soft Matter Physics
- Statistical Mechanics
Background:
- Negative energetic elasticity in gels contradicts traditional elasticity theories.
- A clear explanation for this phenomenon in polymer systems has been lacking.
Purpose of the Study:
- To investigate the origins of negative energetic elasticity in polymer chains.
- To explore its presence in different polymer models.
Main Methods:
- Utilized the weakly self-avoiding walk (Domb-Joyce model) and interacting self-avoiding walk models.
- Employed exact enumeration techniques to analyze polymer behavior.
Main Results:
- Both the Domb-Joyce and interacting self-avoiding walk models demonstrate negative energetic elasticity.
- Identified effective soft-repulsive interactions between polymer segments as the cause.
- Discovered a universal scaling law for internal energy with a common exponent of 7/4 across model crossovers.
Conclusions:
- Negative energetic elasticity is a fundamental property of polymer chains.
- This property is universally observed in polymer networks.
- Effective soft-repulsive interactions drive this phenomenon in polymers.
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