Protein-Enabled Size-Selective Defect-Sealing of Atomically Thin 2D Membranes for Dialysis and Nanoscale Separations.

Atomically thin 2D materials present the potential for advancing membrane separations via a combination of high selectivity (from molecular sieving) and high permeance (due to atomic thinness). However, the creation of a high density of precise nanopores (narrow-size-distribution) over large areas in 2D materials remains challenging, and nonselective leakage from nanopore heterogeneity adversely impacts performance. Here, we demonstrate protein-enabled size-selective defect sealing (PDS) for atomically thin graphene membranes over centimeter scale areas by leveraging the size and reactivity of permeating proteins to preferentially seal larger nanopores (≥4 nm) while preserving a significant amount of smaller nanopores (via steric hindrance).

Kinetic Control of Angstrom-Scale Porosity in 2D Lattices for Direct Scalable Synthesis of Atomically Thin Proton Exchange Membranes.

Angstrom-scale pores introduced into atomically thin 2D materials offer transformative advances for proton exchange membranes in several energy applications. Here, we show that facile kinetic control of scalable chemical vapor deposition (CVD) can allow for direct formation of angstrom-scale proton-selective pores in monolayer graphene with significant hindrance to even small, hydrated ions (K diameter ∼6.6 Å) and gas molecules (H kinetic diameter ∼2.

Nanoporous Atomically Thin Graphene Filters for Nanoscale Aerosols.

Filtering nanoparticulate aerosols from air streams is important for a wide range of personal protection equipment (PPE), including masks used for medical research, healthcare, law enforcement, first responders, and military applications. Conventional PPEs capable of filtering nanoparticles <300 nm are typically bulky and sacrifice breathability to maximize protection from exposure to harmful nanoparticulate aerosols including viruses ∼20-300 nm from air streams. Here, we show that nanopores introduced into centimeter-scale monolayer graphene supported on polycarbonate track-etched supports via a facile oxygen plasma etch can allow for filtration of aerosolized SiO nanoparticles of ∼5-20 nm from air steams while maintaining air permeance of ∼2.

Scalable synthesis of nanoporous atomically thin graphene membranes for dialysis and molecular separations facile isopropanol-assisted hot lamination.

Scalable graphene synthesis and facile large-area membrane fabrication are imperative to advance nanoporous atomically thin membranes (NATMs) for molecular separations. Although chemical vapor deposition (CVD) allows for roll-to-roll high-quality monolayer graphene synthesis, facile transfer with atomically clean interfaces to porous supports for large-area NATM fabrication remains extremely challenging. Sacrificial polymer scaffolds commonly used for graphene transfer typically leave polymer residues detrimental to membrane performance and transfers without polymer scaffolds suffer from low yield resulting in high non-selective leakage through NATMs.

Facile Size-Selective Defect Sealing in Large-Area Atomically Thin Graphene Membranes for Sub-Nanometer Scale Separations.

Atomically thin graphene with a high-density of precise subnanometer pores represents the ideal membrane for ionic and molecular separations. However, a single large-nanopore can severely compromise membrane performance and differential etching between pre-existing defects/grain boundaries in graphene and pristine regions presents fundamental limitations. Here, we show for the first time that size-selective interfacial polymerization after high-density nanopore formation in graphene not only seals larger defects (>0.

Surface Defection Reduces Cytotoxicity of Zn(2-methylimidazole) (ZIF-8) without Compromising its Drug Delivery Capacity.

Zn(2-methylimidazole) (ZIF-8), as one of the most important metal-organic framework (MOF) molecules, is a promising candidate for drug delivery due to its low-density structure, high surface area, and tunable frameworks. However, ZIF-8 exhibits a high cytotoxicity associated with its external hydrophobic surface, which significantly restricts its application in drug delivery and other biomedical applications. Commonly used chemical functionalization methods would convert the hydrophobic surface of ZIF-8 to hydrophilic, but the generated functional groups on its internal surface may reduce its pore sizes or even block its pores.

Memristive Behavior and Ideal Memristor of 1T Phase MoS2 Nanosheets.

Memristor, which had been predicted a long time ago (Chua, L. O. IEEE Trans.