The article titled, "A molecularly impermeable polymer from two-dimensional polyaramids" was published November 13th, 2025 in Journal of Nature. This paper was co-authored by Cody L. Ritt, Michelle Quien, Zitang Wei, Hagen Gress, Mohan T. Dronadula, Kaan Altmisdort, Huong Giang T. Nguyen, Christopher D. Zangmeister, Yu-Ming Tu, Sanjay S. Garimella, Shahab Amirabadi, Michael Gadaloff, Weiguo Hu*, Narayana R. Aluru, Kamil L. Ekinci, J. Scott Bunch & Michael S. Strano.
All polymers exhibit gas permeability through the free volume of entangled polymer chains. By contrast, two-dimensional (2D) materials including graphene stack densely and can exhibit molecular impermeability. Herein, we demonstrate self-supporting, spin-coated 2D polyaramid nanofilms that exhibit nitrogen permeability below 3.1 × 10−9 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). 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.