Jason Holt1, Hyung Gyu Park2, Yinmin Wang1, Costas P. Grigoropoulos2, Michael Stadermann1, Alexander Artyukhin1, Aleksandr Noy1, and Olgica Bakajin1. (1) Biosecurity and Nanosciences Laboratory, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, (2) Mechanical Engineering, University of California, Berkeley, 6177 Etcheverry Hall, Mailstop 1740, Berkeley, CA 94270
We report gas and water flow measurements through microfabricated membranes with sub-2 nm aligned carbon nanotubes as pores. The measured gas flow exceeds predictions of the Knudsen diffusion model by more than an order of magnitude. The measured water flow exceeds values calculated from continuum hydrodynamics models by more than three orders of magnitude and is comparable to flow rates extrapolated from molecular dynamics simulations. The gas and water permeabilities of these nanotube-based membranes are several orders of magnitude higher than those of commercial polycarbonate membranes, despite having order of magnitude smaller pore sizes. These properties should enable fundamental studies of mass transport in confined environments, as well as more energy-efficient nanoscale filtration.