▎ 摘　　要

NOVELTY - Polyethylene glycol terephthalate/graphene two-dimensional layered composite film with T-type channel structure having a two-dimensional layered Emi channel and a single-dimensional micrometer channel, and the two channels are connected vertically to form a T-shaped channel structure, is claimed. USE - The composite film is useful in ion transmission, sieving and detection at aqueous solutions and oil/water interfaces, ion transmission and sieving Emi at resolution in aqueous solution, ion transmission and sieving on polarizable oil/water interface, and electrochemical detection of potassium ion on polarizable oil/water interface (all claimed). ADVANTAGE - The composite film: has simple and fast preparation method. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the polyethylene glycol terephthalate/graphene two-dimensional layered composite film with T-type channel structure, comprising assembling the single-layer graphene nanosheets on the surface of the polyethylene glycol terephthalate submicron porous film by using the vacuum filtration method to obtain the finished product.