Patent ID: 8377831

Claim:
A method comprising: a) loading a solution comprising dispersed nanostructures and a solvent into a vessel; b) adding gaseous antisolvent to the vessel containing the solution to an initial pressure, P 0 , effective to form the solution into a gas-expanded liquid; c) increasing the gas pressure by pressure increment, ΔP i , to a subsequent pressure, P i , at which a particular size fraction of nanostructures, F i , will precipitate from the gas-expanded liquid; d) allowing an equilibration period, t i , to precipitate the size fraction, F i , of nanostructures onto a surface; e) displacing the precipitated size fraction, F i , of nanostructures from the nanostructures remaining dispersed in the gas-expanded liquid; and f) repeating steps c)-e) for i=1 to x times with the remaining solution until all desired size fractions have been precipitated and displaced wherein x=the number of size fractions of nanostructures desired.