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Finite size effects on locating conformational transitions for macromolecules
1Department of Chemical Engineering, Columbia University, New York, New York 10027, USA.
The Journal of Chemical Physics
|December 3, 2008
Summary
Different measures of macromolecule phase transitions yield different temperatures due to finite chain length. Scaling analysis and computer simulations confirm this effect, resolving discrepancies in transition temperature results.
Area of Science:
- Polymer physics
- Statistical mechanics
- Computational chemistry
Background:
- Macromolecule phase transitions, such as collapse or crystallization/melting, are accompanied by peaks in structural and thermodynamic quantities.
- Experimental and simulation studies show these peaks do not always coincide, leading to apparent differences in transition temperatures for finite-length chains.
Purpose of the Study:
- To investigate the discrepancy in transition temperatures observed for finite-length macromolecules.
- To determine if finite chain length is the cause of differing peak locations in transition measures.
Main Methods:
- Utilizing scaling theory, a theoretical framework for understanding systems with scale invariance.
- Verifying theoretical predictions through extensive computer simulations of macromolecule behavior.
Main Results:
- Demonstrated that the non-coincidence of peak locations is a direct consequence of finite chain length.
- Confirmed that scaling arguments accurately predict the behavior of these transition peaks.
Conclusions:
- The observed differences in transition temperatures for finite macromolecules are an artifact of finite chain length.
- Scaling theory provides a robust explanation for these phenomena, consistent with simulation data.
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