New York-based Mattershift has managed to create large-scale carbon nanotube (CNT) membranes that are able to combine and separate individual molecules.

Mattershift designs and manufactures nanotube membranes for carbon-zero fuels, health and performance optimized air and water, and precision medicine. The startup was founded in 2013 to realize the potential of molecular factories, with the ultimate goal of printing matter from the air.

Science Advances – Large-scale polymeric carbon nanotube membranes with sub–1.27-nm pores Abstract
Mattershift reports the first characterization study of commercial prototype carbon nanotube (CNT) membranes consisting of sub–1.27-nm-diameter CNTs traversing a large-area nonporous polysulfone film. The membranes show rejection of NaCl and MgSO4 at higher ionic strengths than have previously been reported in CNT membranes, and specific size selectivity for analytes with diameters below 1.24 nm. The CNTs used in the membranes were arc discharge nanotubes with inner diameters of 0.67 to 1.27 nm. Water flow through the membranes was 1000 times higher than predicted by Hagen-Poiseuille flow, in agreement with previous CNT membrane studies. Ideal gas selectivity was found to deviate significantly from that predicted by both viscous