Gold coated block copolymer membranes with precisely controllable pore size for molecule separations

摘要

The need to physically separate similarly sized solutes is a ubiquitous problem in biological research and in the production of biomolecules and other nanoparticles. Compared to resin-based chromatography, membrane separations are simpler, more energy efficient, and more readily scaled between laboratory and industry. To create idealized membranes for size-based separations, researchers have developed nanoporous membranes with well-defined and tunable pore sizes. Aluminum oxide and track-etched membranes are commercially available examples, but the pores in these membranes are too large (>20nm) for many biological separations. Silicon patterning techniques have been used to create membranes with uniform 10 nm wide pores, but the low porosity (～1%) of these membranes limit the transport. Ultrathin silicon membranes (～10 nm) with defined pores (25 nm) were first created using an ion-beam drilling process that is far too slow for up-scaling. Recently, track-etching technology has been applied to SiN membranes to create 100 nm thick membranes with pore sizes that can be tuned between 10 nm and 50 nm depending on the time allotted to etching; however, this technique faces high volume manufacturing challenges.