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A molecularly impermeable polymer from two-dimensional polyaramids
Cody L Ritt1,2, Michelle Quien1, Zitang Wei1
1Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Nature
|November 12, 2025
Summary
Researchers developed solution-synthesized two-dimensional (2D) polyaramid nanofilms with ultra-low gas permeability. These novel 2D polymer materials offer superior barrier properties for advanced applications.
Area of Science:
- Materials Science
- Polymer Chemistry
- Nanotechnology
Background:
- Conventional polymers exhibit inherent gas permeability due to chain entanglement.
- Two-dimensional (2D) materials like graphene offer molecular impermeability but are challenging to synthesize in solution.
- Achieving solution-processable 2D polymers with impermeability has been a significant scientific goal.
Purpose of the Study:
- To synthesize self-supporting, spin-coatable 2D polymer nanofilms.
- To evaluate the gas permeability properties of these novel 2D polymers.
- To explore the potential applications of these impermeable 2D polymers.
Main Methods:
- Solution polymerization via poly-condensation to create 2D polymers.
- Spin-coating technique to form self-supporting nanofilms.
- Gas permeability measurements using nitrogen and other gases (He, Ar, O2, CH4, SF6).
- Optical interference for mechanosensitive bulge formation and stability assessment.
- Fabrication of 2D polymer resonators and perovskite-coated films.
Main Results:
- Demonstrated self-supporting, spin-coated 2D polyaramid nanofilms.
- Achieved ultra-low nitrogen permeability (<3.1 × 10^-9 Barrer), nearly four orders of magnitude lower than existing polymers.
- Exhibited similar low permeability for other tested gases.
- Observed stable, mechanosensitive gas-filled bulges exceeding three years.
- Fabricated 2D polymer resonators with high resonance frequencies (~8 MHz) and quality factors (up to 537).
- Demonstrated a 14-fold reduction in perovskite lattice degradation rate with a 2D polymer coating.
Conclusions:
- Successfully synthesized solution-processable 2D polyaramid nanofilms with unprecedented molecular impermeability.
- These 2D polymers represent a new class of high-performance barrier materials.
- The developed materials enable advanced applications in resonators and protective coatings for sensitive materials.
- This breakthrough advances the development of sustainable, high-efficiency barrier technologies.
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