▎ 摘　　要

NOVELTY - Preparation of polymer-supported graphene membrane involves (a) providing a graphene membrane on a sacrificial support, (b) providing a solution of a polymer with a glass transition temperature of 200 degrees C or more in organic solvent, (c) covering graphene membrane on sacrificial support with polymer solution to form a regular polymer solution film on top of graphene membrane on a sacrificial support, and (d) placing polymer coated graphene membrane on sacrificial support in a coagulation bath comprising a non-solvent comprising 55-100 wt.% alcohol to induce a non-solvent induced phase separation at 0-60 degrees C. The solution comprises 5-45 wt.% polymer (i), and 5-65 wt.% dope additive (excluding 5) (ii) chosen from polymeric agent such as polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol and polyethylene oxide, and non-polymeric agent such as glycerol, propionic acid, surfactants such as Span-80 (RTM: sorbitan monooleate). USE - Preparation of polymer-supported graphene membrane used in gas selective filter for separating hydrogen, helium and carbon dioxide from nitrogen and methane from larger molecular weight hydrocarbons e.g. ethene (all claimed). ADVANTAGE - The method provides a supportive polymeric layer on a graphene layer with suitable mechanical properties for ensuring a robust support, while maintaining suitable gas sieving properties. The supported graphene membrane can be easily handled without inducing cracks and defects. DETAILED DESCRIPTION - Preparation of polymer-supported graphene membrane involves (a) providing a graphene membrane on a sacrificial support, (b) providing a solution of a polymer with a glass transition temperature of 200 degrees C or more in organic solvent, (c) covering graphene membrane on sacrificial support with polymer solution to form a regular polymer solution film on top of graphene membrane on a sacrificial, and (d) placing polymer coated graphene membrane on sacrificial support in a coagulation bath comprising a non-solvent comprising 55-100 wt.% alcohol to induce a non-solvent induced phase separation at 0-60 degrees C. The solution comprises 5-45 wt.% polymer (i) and 5-65 wt.% dope additive (excluding 5) (ii) chosen from polymeric agent such as polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol and polyethylene oxide, and non-polymeric agent such as glycerol, propionic acid, surfactants such as Span-80 (RTM: sorbitan monooleate). The viscosity of resulting dope solution at room temperature is 0.5-12.75 Pa.second, preferably 0.8-3 Pa.second at 298 K. An INDEPENDENT CLAIM is included for a gas selective filter, which comprises the polymer-supported graphene membrane.