High-Performance Separation of Nanoparticles with Ultrathin Porous Nanocrystalline Silicon Membranes

Porous nanocystalline silicon (pnc Si) is a 15 nm thin free standing membrane material with Applications in small scale separations, biosensors, cell culture, and lab-on a-chip devices Pnc Si has already been shown to exhibit high permeability to diffusing species and selectivity based on molecular size or charge. In this report, we characterize properties of pc Si In pressurized flows We compare results to long standing theories for through short pores using actual pore distributions kilned directly from electron micrographs The measured water permeability is in agreement with theory over a wide range of pore sizes and porosities and orders of magnitude higher than those exhibited by commercial ultrafiltration and experimental carbon nanotube membranes We also show that pnc Si membranes can be used in dead end filtration to,fractionate gold nanoparticles and protein size ladders with better than 5 nm resolution, insignificant sample loss, and little dilution of the filtrate These performance characteristics, combined with scalable manufacturing, make pnc Si filtration a straightforward solution to many nanoparticle and biological separation problems