Alternative methods to prepare free standing graphene oxide multilayers/laminates is to use repeated drop casting or spin coating.
[3] Studies of graphite oxide membranes were performed by Hanns-Peter Boehm, the German scientist who invented the term "graphene", in 1960.
The paper titled "Graphite Oxide and its membrane properties" reported synthesis of "paper-like foils" with 0.05 mm thickness.
[5] This study was later expanded to demonstrate that several salts (for example KCl, MgCl2) diffuse through the graphene oxide membrane if it is immersed in water solution.
[7] Retention rates over 90% were reported in a 1960 study for NaCl solutions using stabilized graphene oxide membranes in reverse osmosis setup.