▎ 摘　　要

NOVELTY - Method for molecular dynamics simulation of structural characteristics of sandwich graphene oxide/binary ionic liquid lubricating film involves (1) selecting single crystal silicon cell in the structure database of Materials Studio, (2) using the supercell to construct the supercell of the silicon unit cell, expanding to silicon substrate, (3) grafting hydroxyl molecules on the silicon substrate in step (2), obtaining hydroxylated silicon substrate, bonding N-3-(trimethoxysilyl)propylethylenediamine (DA) molecules to hydroxylated silicon substrate surface, forming DA monolayer self-assembled molecular film (DA SAM), calculating the coverage of graphene oxide (GO) molecules on the surface of DA SAM, establishing coverage rate, preparing sandwich graphene oxide film (DA-GO-DA), creating 1-carboxyethyl-3-methylimidazole chloride salt ionic liquid molecule grafting onto surface of DA-GO-DA, and e.g. performing optimal coverage of (GO) molecules on the surface of (DA SAM). USE - Method for molecular dynamics simulation of structural characteristics of sandwich graphene oxide/binary ionic liquid lubricating film. ADVANTAGE - The method provides interlayer graphene oxide/binary ion liquid film structure has low adhesion, high bearing, antifriction, wear-resistant interlayer binary ion liquid film structure characteristic from the molecular dynamics angle, and provides a feasible technical means for further analysis of various characteristics of the film, and provides theoretical basis for designing high performance anti-friction and anti-adhesion lubricating film. DETAILED DESCRIPTION - Method for molecular dynamics simulation of structural characteristics of sandwich graphene oxide/binary ionic liquid lubricating film involves (1) selecting single crystal silicon cell in the structure database of Materials Studio, (2) using the supercell to construct the supercell of the silicon unit cell selected in step (1), expanding to silicon substrate, (3) grafting hydroxyl molecules on the silicon substrate in step (2), obtaining hydroxylated silicon substrate, (4) preparing N-3-(trimethoxysilyl)propylethylenediamine (DA) according to the parameters of DA molecules, bonding the DA molecule to hydroxylated silicon substrate surface through silicon-oxygen covalent bond, forming DA monolayer self-assembled molecular film (DA SAM), (5) constructing graphene oxide (GO) model based on the oxygen content of GO and the ratio of oxygen-containing functional groups through the chemical bond connection between oxygen and carboxylic acid on the surface and amine at the end of the base DA molecule in (4), using the Discover module in Material Studio software, calculating the coverage of GO molecules on the surface of DA SAM, obtaining coverage rate when the GO molecule with the smallest average single-strand energy, which is the optimal coverage of GO molecules on the surface of DA SAM, (6) calculating the average single-stranded energy of GO molecules at different graft positions on the surface of DA SAM based on the optimal coverage of GO molecules on the surface of DA SAM, obtaining GO molecular arrangement mode when the average single-strand energy is the smallest, which is the best grafting position of GO molecules on the surface of DASAM to form GO self-assembled molecular film (DA-GO), (7) establishing a single layer film on the surface of DA-GO, using Discover module in Material Studio software, calculating the coverage of DA molecules on the surface of DA-GO, obtaining coverage rate when the DA molecule with the smallest average single-stranded energy, which is the optimal coverage rate of DA molecules on the upper surface of DA-GO, (8) calculating the average single-stranded energy of DA molecules at different graft positions on the surface of DA-GO based on the optimal coverage of DA molecules on the upper surface of DA-GO, obtaining DA molecule arrangement mode when the average single-strand energy is the smallest, which is the best grafting position of DA molecules on the upper surface of DA-GO to form a sandwich graphene oxide film (DA-GO-DA), (9) creating 1-carboxyethyl-3-methylimidazole chloride salt ionic liquid molecule (compound (I)) according to the parameters of compound (I), grafting onto the surface of DA-GO-DA through an amide bond, using Discover module in Material Studio software, calculating the coverage of compound (I) molecules on the surface of DA-GO-DA, obtaining coverage rate when the compound (I) molecule with the smallest average single-strand energy, which is the optimal coverage of compound (I) molecules on the surface of DA-GO-DA, (10) calculating the average single-strand energy of compound (I) molecule at different graft positions on the surface of DA-GO-DA based on the optimal coverage of compound (I) molecules on the surface of DA SAM, obtaining compound (I) molecular arrangement when the average single-stranded energy is the smallest, It is the best grafting position of compound (I) molecule on the surface of DA-GO-DA to form a sandwich graphene oxide/binary ionic liquid lubricating film (DA-GO-DA-compound (I)), (11) preparing 1-dodecyl-3-methylimidazole hexafluorophosphate ionic liquid (compound (II)) according to the parameters of compound (II) and ratio of compound (I) and compound (II) is 1:1-1:10, binding compound (II) molecules around compound (I) molecules through physical adsorption, calculating the average single-stranded adsorption energy of compound (II) molecules, obtaining a binary doped ionic liquid lubricating film (DA-GO-DA-compound (I)-compound (II)), and (12) performing optimal coverage of GO molecules on the surface of DA SAM, optimal coverage of DA molecules on the upper surface of DA-GO, optimal coverage of the compound (I) molecule on the surface of DA-GO-DA, optimal coverage of GO molecules on the surface of DA SAM, optimal coverage of DA molecule on the upper surface of DA-GO and optimal coverage of compound (I) molecule on the surface of DA-GO-DA. The molecular ratios of compound (I) and compound (II) in step (11) are the structural characteristics of the interlayer graphene oxide/binary ionic liquid lubricating film. In step (11), when the average single-stranded adsorption energy of compound (II) molecule is the smallest, the corresponding interface between the compound (II) layer and the compound (I)/DA/Si layer has the largest binding energy, the structure of the system is also the most stable, and compound (I) and compound (II) are the most stable.