ИСТИНА

Progress in membrane technologies allows to create membranes, which can change transport properties under the external stimuli such as temperature, electric, magnetic or electromagnetic fields. On the other side, the interest in two dimensional nanosheet based membranes has grown up. Membranes based on graphene oxide (GO), transition metal dichalcogenides, and MXene have been studied. Two-dimensional materials are characterized labyrinth mechanism of mass transport, in which molecules are transported through interlayer space or through the defects in nanosheets [1]. However, only a few works devoted to switchable membranes based on two-dimensional materials have been published [2]. Thus the specific goal of the current study is preparation membranes based on graphene oxide modified by azo-group molecules, which can change their transport properties under light irradiations due to cis-trans isomerization of azo-group. Graphene oxide was obtained by modified Hummer’s method the ratio of graphite and KMnO4 was 1:20. The lateral size is about 800 nm, C/O ratio is 1,7. 10 mg of GO was modified by 10 mmol NaNO2 and 10 mmol aniline in 6 M hydrochloric acid. The selective layer of modified graphene oxide was formed on anodic alumina support by spin-coating technique. For formed membrane water vapor permeance was measured. The permeance increase under UV irradiation and decrease under IR irradiation. The changing of water vapor permeance under UV light may be explained by the transition to a cis isomer of immobilized azobenzene on graphene oxide, leading to changing interlayer distance. This property of mass transport changing under external stimuli may be found application in the separation of mixtures with various content.