In recent years, numerous studies have focused on enhancing water permeability and ion retention by oxidizing pristine graphene membranes. Despite advanced modification and successful applications, the physical properties involved in the separation processes by graphene oxide nanochannels, such as the dielectric constant are not fully understood. A series of molecular dynamics simulations are carried out in this work to investigate the dielectric properties of aqueous solution in both pristine and oxidized bilayer graphene membranes. Results show that the dielectric constant decreases with the increase of the oxidation ratio as the oxidation ratio of the channel is less than 20%. However, the dielectric properties violate the previous trend as the oxidation rate continues to increase up to 40%. We show that the former is due to the formation of hydrogen bonds between water and graphene oxide substrate, leading to the decrease of water dipole fluctuation and the dielectric constant and the latter is caused by the formation of hydrogen bonds between adjacent OH groups on the graphene sheets at high oxidation rate, thus reducing the ability to attract water and formation of water-substrate hydrogen bonds.

近年来，许多研究集中于通过氧化原始石墨烯膜来提高水的渗透性和离子保留。尽管进行了先进的修改和成功的应用，但是对由氧化石墨烯纳米通道进行的分离过程所涉及的物理性质（例如介电常数）尚未完全了解。在这项工作中进行了一系列的分子动力学模拟，以研究水溶液在原始和氧化双层石墨烯膜中的介电性能。结果表明，当沟道的氧化率小于20％时，介电常数随氧化率的增加而降低。然而，随着氧化速率继续增加高达40％，介电性能违反了以前的趋势。