▎ 摘　　要

NOVELTY - The method involves providing a polymer substrate that is in range of 5 microns or less in thickness. The substrate is ion tracked. The flux of ions passing through the substrate is controlled to achieve a desired pore density. The tracked substrate is etched with an etchant to produce several pores (106) in the substrate. The properties of the etching are controlled to achieve a desired pore size. The track-edged substrate is used as a support substrate for one of a single-layer graphene film, a multi-layer graphene film, a stack of graphene films, a nanostructure of graphene flakes, or a nanostructure of graphene platelets. USE - Method for producing modified substrate such as polycarbonate, polyvinylidene fluroride, polyimide, polyurethane, polyarylate, polyethylene terephthalate, poly-methyl methacrylate, or polypropylene used for forming or modifying substrates used for making membranes such as high-selectivity filtration membrane (all claimed) and track-etched membrane for biological application such as implantation in human body, filters and support substrates for two-dimesional (2D) materials. ADVANTAGE - The porosity of the overall membrane is maintained while maintaining the membrane durability. The porosity of the etched areas can be increased without compromising the overall structural integrity of the membrane by using a mask to increase the mechanical properties for the membrane. The ultra-thin, high porosity membranes can be produced with thinner, more flexible, smoother, and more porous and help to preserve the properties of the graphene in the overall layered material. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for: (1) a high-selectivity filtration membrane. DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view illustrating an image of the membrane. High porosity membrane (100) Pore (106)