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Updated: Jul 23, 2026
06:55
Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Two-dimensional melting transition observed in a block copolymer
D E Angelescu1, C K Harrison, M L Trawick
1Department of Physics, PRISM-Princeton University, Princeton, New Jersey 08544, USA.
Physical Review Letters
|August 11, 2005
Summary
This study observed two-dimensional melting in a diblock copolymer film. Evidence suggests a first-order melting transition, with underlying second-order characteristics in the liquid phase.
Area of Science:
- Materials Science
- Polymer Physics
- Soft Matter Physics
Background:
- Two-dimensional (2D) melting is a fundamental phase transition in condensed matter physics.
- Understanding melting in 2D systems is crucial for various applications, including thin films and nanotechnology.
- Diblock copolymers offer a unique platform to study 2D phase behavior due to their self-assembly properties.
Purpose of the Study:
- To observe and characterize the two-dimensional melting transition in a monolayer film of sphere-forming diblock copolymers.
- To investigate the temperature dependence of critical parameters during the phase transition.
- To determine the order of the melting transition and explore underlying critical phenomena.
Main Methods:
- Annealing a monolayer diblock copolymer film within a controlled temperature gradient.
- Observing the transition from a hexatic phase to a liquid phase in a single experiment.
- Measuring orientational and translational correlation lengths and topological defect density.
Main Results:
- A complete record of the two-dimensional melting transition was obtained.
- The melting transition was identified as first-order.
- Correlations in the liquid phase suggest a preempted underlying second-order transition.
Conclusions:
- The study provides direct evidence of two-dimensional melting in a diblock copolymer system.
- The observed transition is primarily first-order, but with indications of a hidden second-order critical point.
- This work contributes to the fundamental understanding of phase transitions in low-dimensional soft matter systems.
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