In a landmark breakthrough that could redefine the future of materials science and protective coatings, researchers at the Massachusetts Institute of Technology have engineered a novel lightweight polymer film boasting near-perfect gas impermeability. This extraordinary characteristic not only places the material on par with molecularly-thin crystalline substances like graphene but also heralds transformative applications in sectors ranging from solar energy to food preservation. Unlike conventional polymers, which exhibit measurable gas permeability due to microscopic gaps within their molecular structures, this newly developed polymer film forms an almost absolute barrier, a feat never before achieved by any polymer.
The genesis of this innovation lies in the creation of a two-dimensional polyaramid polymer named 2DPA-1, characterized by its ultrathin molecular sheets that self-assemble via hydrogen bonding. The polymerization process utilizes melamine monomers, containing intricately arranged carbon and nitrogen atoms, which expand in two dimensions to generate nanoscopic disks. These disks subsequently stack with remarkable precision, with hydrogen bonds ensuring strong interlayer adhesion. The resulting material possesses astonishing mechanical strength, surpassing that of steel, yet at only one-sixth of steel’s density.
One of the most compelling demonstrations of 2DPA-1’s impermeability involved suspending films over microfabricated wells to create microscopic gas-filled bubbles. Unlike typical polymers where entrapped gases diffuse rapidly outwards, causing bubbles to collapse, 2DPA-1 bubbles remained inflated for extraordinary durations. Some bubbles generated in 2021 have stayed stable and intact for years, an unexpected observation that challenged conventional understanding of molecular transport across polymeric membranes. Prolonged and meticulous monitoring confirmed the material’s effectiveness in completely blocking nitrogen gas diffusion.
Traditional polymer films resemble tangled masses of spaghetti-like chains of molecules with inherent void spaces, which facilitate gas diffusion. This inherently limits their barrier performance, making them unsuitable for high-demand applications necessitating airtight encapsulation. In stark contrast, the 2DPA-1 film eliminates free volume between polymer chains by forming flawless two-dimensional nanodisks that pack tightly without spaces, thus preventing molecular permeation. This lack of any interstitial volume is unprecedented for polymers and explains its exceptional impermeability.
The team further extended their investigations to assess gas barrier capabilities against various gases including helium, argon, oxygen, methane, and sulfur hexafluoride. Across the board, 2DPA-1 exhibited permeability levels at least ten thousand times lower than any other polymer known to date. This performance rivals that of graphene, which is known to be impermeable due to its perfect crystalline lattice. However, unlike graphene, 2DPA-1 offers superior practicality due to ease of manufacture and scalability.
Graphene’s remarkable impermeability has fascinated scientists for years, spurring attempts to exploit it as protective coatings for sensitive devices like solar cells. Nonetheless, graphene’s fabrication challenges—restricted to small crystalline patches that cannot be smoothly or reliably applied over large areas—have limited its commercial viability. Graphene sheets tend to slide over one another under shear due to negligible interlayer friction, complicating their assembly into continuous films. This is where 2DPA-1 distinguishes itself by having strong hydrogen bonds between layers, anchoring the sheets together and allowing them to be deposited reliably as uniform coatings.
The practical ramifications of this technology are profound. In experimental demonstrations, a mere 60-nanometer-thick coating of 2DPA-1 significantly increased the lifespan of perovskite crystals by several weeks. Perovskites hold vast promise as cost-effective and lightweight solar cell materials but are notoriously susceptible to rapid degradation, posing a critical hurdle to commercialization. Extending their operational stability via molecularly impermeable coatings like 2DPA-1 represents an important step forward in renewable energy technologies. Thicker coatings are projected to deliver even longer protection.
Beyond photovoltaics, this polymer’s ultrahigh gas impermeability opens diverse possibilities for safeguarding infrastructure vulnerable to environmental degradation and corrosion. Bridges, buildings, rail networks, automotive vehicles, aircraft, and maritime vessels—all exposed to damaging atmospheric agents—could benefit enormously from this coating technology. Moreover, food and pharmaceutical industries stand to gain by incorporating the polymer into packaging systems aimed at significantly prolonging shelf life and maintaining product integrity.
Beyond impermeability, 2DPA-1’s combination of strength and thinness makes it ideal for advanced nanomechanical devices. The researchers successfully engineered nanoscale resonators—essentially tiny drums that vibrate at specific frequencies—using the polymer. Current resonators used in phones and communication devices are relatively large, but tamping down their size to submicron levels has been a long-standing challenge. Such miniaturization could drastically reduce power consumption and device size, revolutionizing signal processing and sensing technologies.
These resonators also have remarkable sensitivity in detecting minute gas molecules, underscoring the multifaceted potential of 2DPA-1 in sensing applications. The combination of impermeability, mechanical robustness, and processability situates this polymer as a versatile platform material for next-generation electronics, coatings, sensors, and energy devices. This study not only expands the frontiers of polymer chemistry but also exemplifies how molecular design strategies can yield materials with unparalleled properties once thought exclusive to crystalline solids.
The research was enabled by advanced techniques that allow solution-phase polymerization, scalable production, and deployment of the films on various substrates. Supported in part by funding from the U.S. Department of Energy’s Energy Frontier Research Center and the National Science Foundation, this work sets the stage for rapid translation of 2DPA-1 into industrial applications. It also highlights the synergy of interdisciplinary collaboration across chemical engineering and mechanical engineering disciplines, driven by visionary investigators including Prof. Michael Strano at MIT and Prof. Scott Bunch at Boston University.
Ultimately, 2DPA-1’s emergence as a molecularly impermeable polymer heralds a new era in materials innovation, where ultrathin films rival the performance of defect-free crystalline materials but with vastly improved practical versatility. The implications are enormous, ranging from protecting cutting-edge renewable energy technologies to enhancing everyday products like food packaging, while simultaneously enabling revolutionary advances in nanoscale devices. This remarkable marriage of advanced polymer chemistry and nanotechnology promises to redefine the boundaries of materials science and sustainable technology development.
Subject of Research:
Development and characterization of a gas-impermeable two-dimensional polyaramid polymer film and its potential applications in protective coatings, solar energy, and nanomechanical devices.
Article Title:
A molecularly impermeable polymer from two-dimensional polyaramids
News Publication Date:
12-Nov-2025
Web References:
10.1038/s41586-025-09674-9
Image Credits:
MIT
