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Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers
Published on: June 20, 2019
The packing of granular polymer chains.
Ling-Nan Zou1, Xiang Cheng, Mark L Rivers
1James Franck Institute and Department of Physics, University of Chicago, Chicago, IL 60637, USA. zou@uchicago.edu
Science (New York, N.Y.)
|October 17, 2009
Summary
Flexible chains form low-density structures, with rigidity from their backbone. Compaction leads to loop formation, enabling chain packing akin to jamming. This resembles polymer glass transitions.
Area of Science:
- Physics of soft matter
- Materials science
- Polymer physics
Background:
- Rigid particle packing relies on contact number for stability.
- Packing flexible, extended objects requires new theoretical frameworks.
- Understanding chain packing is crucial for materials with tunable properties.
Purpose of the Study:
- To investigate the disordered packing of flexibly connected hard sphere chains.
- To elucidate the structural and mechanical properties of chain packings.
- To draw parallels between chain packing and polymer physics phenomena.
Main Methods:
- Utilizing X-ray tomography to visualize chain structures.
- Analyzing the mechanical rigidity and structural evolution under compaction.
- Comparing packing behavior to established models of jamming and glass transitions.
Main Results:
- Long chains form low-density structures with backbone-dominated rigidity.
- Compaction induces the formation of semi-rigid loops along the chains.
- Chain packing behavior is analogous to the jamming of these loops.
- Similarities observed between chain packing and the glass transition in polymers.
Conclusions:
- The mechanical stability of flexible chain packings is governed by backbone and loop formation.
- Chain packing can be conceptualized as a jamming transition of flexible elements.
- The study reveals a strong connection between disordered chain packing and polymer glass transition physics.
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