Enhanced water transport in 8Å diameter carbon nanotube porins.

Living systems move ions and small molecules across biological membranes using protein pores that rely on nanoscale confinement effects to achieve efficient and exquisitely-selective transport. I will show that carbon nanotube porins—pore channels formed by ultra-short carbon nanotubes assembled in a lipid membrane—can exploit similar physical principles to transport water, protons, and small ions with efficiency that rivals and sometimes exceeds that of biological channels. I will discuss the role of molecular confinement in these pores, and show how it can enhance water transport efficiency, and influence the mechanisms of ion selectivity in these pores. Overall, carbon nanotube porins represent a simple and versatile biomimetic membrane pore that is ideal for studying nanoscale transport phenomena, and building the next generation of separation technologies and biointerfaces.