A molecularly impermeable polymer from two-dimensional polyaramids
All polymers exhibit gas permeability through the free volume of entangled polymer chains<sup>1-3</sup>. By contrast, two-dimensional (2D) materials including graphene stack densely and can exhibit molecular impermeability<sup>4-6</sup>. Solution-synthesized 2D polymers that exhibit the latter by poly-condensation have been a longstanding goal. Herein, we demonstrate self-supporting, spin-coated 2D polyaramid nanofilms that exhibit nitrogen permeability below 3.1 × 10<sup>-</sup><sup>9</sup> Barrer, nearly four orders of magnitude lower than every class of existing polymer, and similar for other gases tested (helium, argon, oxygen, methane and sulfur hexafluoride). Optical interference during the pressurization of nanofilm-coated microwells allows measurement of mechanosensitive rim opening and sealing, creating gas-filled bulges that are stable exceeding three years. This discovery enables 2D polymer resonators with high resonance frequencies (about 8 MHz) and quality factors up to 537, similar to graphene. A 60-nm coating of air-sensitive perovskites reduces the lattice degradation rate 14-fold with an oxygen permeability of 3.3 × 10<sup>-8</sup> Barrer. Molecularly impermeable polymers promise the next generation of barriers that are synthetically processable, chemically amenable and maximize molecular rejection with minimal material, ultimately advancing sustainability goals.
Authors
- Zitang Wei (ORCID: https://orcid.org/0000-0002-7391-0342)
- Sanjay Garimella (ORCID: https://orcid.org/0009-0000-0430-5205)
- Christopher D. Zangmeister (ORCID: https://orcid.org/0000-0002-6026-9293)
- Michael S. Strano (ORCID: https://orcid.org/0000-0003-2944-808X)
- Mohan Teja Dronadula (ORCID: https://orcid.org/0000-0002-1240-0373)
- Shahab Amirabadi
- K. L. Ekinci (ORCID: https://orcid.org/0000-0002-5019-5489)
- Weiguo Hu (ORCID: https://orcid.org/0000-0002-7868-1657)
- Huong Giang T. Nguyen (ORCID: https://orcid.org/0000-0002-1052-7565)
- Narayana R. Aluru (ORCID: https://orcid.org/0000-0002-9622-7837)
- Cody L. Ritt (ORCID: https://orcid.org/0000-0002-3215-1685)
- Yuming Tu (ORCID: https://orcid.org/0000-0002-2007-5005)
- Hagen Gress (ORCID: https://orcid.org/0000-0002-5950-8584)
- Michelle Quien (ORCID: https://orcid.org/0000-0003-4990-2577)
- Kaan Altmisdort (ORCID: https://orcid.org/0009-0002-3523-8572)
- Michael Gadaloff (ORCID: https://orcid.org/0009-0004-0246-0868)
- J. Scott Bunch (ORCID: https://orcid.org/0000-0002-1527-2979)
Institutions
- Boston University (US)
- National Institute of Standards and Technology (US)
- National Taiwan University (TW)
- University of Colorado Boulder (US)
- University of Massachusetts Amherst (US)
- IIT@MIT (US)
- Boston University Academy (US)
- Massachusetts Institute of Technology (US)
- The University of Texas at Austin (US)
Publication Details
- Journal
- Nature
- Published
- 2025-11-12
- DOI
- https://doi.org/10.1038/s41586-025-09674-9
- Citations
- 4
- Primary Topic
- Covalent Organic Framework Applications
- Type
- article
- Field-Weighted Citation Impact
- 2.07
Funders
- National Science Foundation
- U.S. Department of Energy
- University of Texas at Austin
- National Institute of Standards and Technology
- Office of Science
- Division of Civil, Mechanical and Manufacturing Innovation
- Basic Energy Sciences