Ion transport in sub-1-nm carbon nanotube porins.

Controlling water an ion transport on a molecular scale is important for applications ranging from water treatment, to membrane separations, to bioelectronic interface design. Living systems are adept at moving ions and small molecules across biological membranes using protein pores that rely on nanoscale confinement to achieve efficient and exquisitely selective transport. I will show that carbon nanotube porins—pore channels formed by short carbon nanotubes assembled in a lipid membrane—can exploit similar physical principles to transport ions and achieve differential ion selectivity. I will discuss the role of molecular confinement and ion interactions with the nanopore walls and show how these phenomena enhance water and ion transport efficiency and influence the mechanisms of ion selectivity and electroosmotic coupling in these pores. Overall, carbon nanotube porins represent a versatile biomimetic membrane pores that are ideal for fundamental nanofluidics studies and for building the next generation of separation technologies.