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Long-range density fluctuations in a symmetric diblock copolymer.
1Hashimoto Polymer Phasing Project, ERATO, Japan Science and Technology Corporation, Kyoto 606-8501, Japan.
Summary
Excess small-angle scattering was observed in diblock copolymers near the order-disorder transition. This scattering arises from density differences between the ordered and disordered phases in the coexistence region.
Area of Science:
- Polymer science
- Materials science
- Soft matter physics
Background:
- Diblock copolymers exhibit complex phase behavior near the order-disorder transition.
- Understanding scattering phenomena is crucial for characterizing polymer morphology.
Purpose of the Study:
- To experimentally investigate the origin of excess small-angle scattering in diblock copolymers.
- To identify the conditions under which this scattering occurs.
Main Methods:
- Utilizing ultra-small-angle X-ray scattering (USAXS) to probe nanoscale structures.
- Examining a nearly symmetric diblock copolymer system.
Main Results:
- Observed excess small-angle scattering exclusively in the two-phase coexistence region.
- This phenomenon occurs near the order-disorder transition temperature.
- Attributed excess scattering to density differences between ordered and disordered phases.
Conclusions:
- The density contrast between coexisting ordered and disordered phases is the source of excess scattering.
- This finding provides insights into the structural characteristics of copolymers at phase transitions.