Ultimate Permeation Across Atomically Thin Porous Graphene

Thin and Selective Outpourings When using a membrane to separate materials, the efficiency of the separation is limited by how fast the gas or liquid passes through the membrane and by how selective it is. Thinner membranes usually allow for faster flow rates but are usually less selective. Attempting to maintain selectivity, Celebi et al. (p. 289 ) developed a sophisticated way to drill holes of controlled diameter in a graphene sheet about two layers thick. For such a thin membrane, the primary barriers to separation come from entrance and exit from the holes and not from the motion through the membrane.