Related Experiment Video
Updated: May 13, 2025
06:44
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
68.9K
Dynamic Molecular Cocrystals with Alkyl Chain Dependent Thermosalient Phase Transitions
Jiantao Meng1, Yuan Su2, Hang Zhu1
1Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, P. R. China.
Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
|April 15, 2025
Summary
Researchers developed new molecular crystals that change shape with heat, enabling programmable mechanical motions. These smart materials show tunable phase transitions and dramatic volume changes, paving the way for advanced actuators and sensors.
Area of Science:
- Materials Science
- Crystallography
- Supramolecular Chemistry
Background:
- Thermally responsive molecular crystals are key for smart actuators and sensors.
- Precise control over their phase transition thermodynamics is a significant challenge.
Purpose of the Study:
- To design molecular crystals with tunable thermo-mechanical properties.
- To investigate the relationship between coformer structure and phase transition behavior.
Main Methods:
- Synthesis of isomorphic 5-fluorocytosine/fatty acid cocrystals.
- Characterization of phase transition thermodynamics and mechanisms.
- Analysis of mechanical responses during phase transitions.
Main Results:
- Phase transition temperatures varied by 100 K with increasing alkyl chain length.
- Two distinct transition pathways were observed: cooperative single-crystal-to-single-crystal and reconstructive.
- Cooperative transitions showed significant expansion (+64.4%) and contraction (-16.9%), leading to dynamic motions.
- Transition temperatures linearly correlated with coformer chain length due to hydrophobic interactions.
Conclusions:
- A versatile approach for designing molecular crystals with tunable thermo-mechanical properties was established.
- The findings offer new opportunities for developing dynamic functional materials.
- Understanding transition pathways is crucial for controlling mechanical responses.
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