Intelligent Molecular Separation And Applications Based On Stimuli-responsive Layered Thin Film Material

In recent years,layered thin film materials have been widely used in the field of membrane separation due to their excellent performance,including water treatment,gas separation,dye removal,and ion screening.However,the rapid development of modern technology has put forward higher application requirements for membrane separation technology,and there is an urgent need to develop intelligent membranes that can adapt to changes in environment and separation requirements and improve membrane permeability and selectivity by responding to external stimuli.Common external stimuli include light,p H,temperature,electric field,and magnetic field.To improve the responsiveness of separation membranes to external stimuli,the selection of membrane materials is crucial.Conventional polymer material membranes have good mechanical properties and strong porous adsorption properties,but their channel size controllability is low and their response speed is slow.Layered thin film materials have been widely studied due to their advantages such as simple preparation methods,adjustable interlayer spacing,and fast response speed This paper focuses on the intelligent regulation of flux and energy consumption in wastewater treatment.By utilizing highly conductive MXene layered membranes,electric field enhanced water infiltration and efficient dye separation are achieved.By utilizing photoresponsive carbon nitride layered films,photoinduced ion selective transport has been achieved,while combining the photocatalytic degradation of dyes and bactericidal ability of carbon nitride,photoinduced salt difference power generation in wastewater and synchronous removal of pollutants and bacteria have been achieved.The main research findings are as follows:1.Based on the electric field response of MXene layered membrane,water permeation and dye separation can be controlled.The MXene lamellar membrane was obtained by vacuum filtration.Through experimental and theoretical investigation,it was found that there is no water flux and sieving performance when no voltage is applied to the membrane,but applying negative voltage to the membrane can increase the interaction force between MXene and water,thus making the hydrophilicity of the MXene membrane increase and the water flux of the membrane increase greatly.Furthermore,due to the narrow layer spacing of the membranes,they can effectively retain dyes and have a high retention rate under voltage.This study provides a new idea for the regulation of water flux in the field of water treatment.2.Photocatalytic wastewater osmotic energy conversion based on asymmetric carbon nitride films.This asymmetric structure enhances the light absorption coefficient and generates a built-in electric field to promote charge separation,thereby increasing the ion transport rate and enabling the photocatalytic salt differential generation of electricity from carbon nitride films by chemical vapour deposition.As a metal-free semiconductor material,light induces electron-hole separation and produces active substances that can degrade organic pollutants as well as bacterial sterilisation,which allows C₃N₄ membranes to treat wastewater while converting permeate energy with wastewater.This research opens up a new avenue for the use of wastewater resources and the extraction of osmotic energy and will also help explore multifunctional material systems for other practical applications related to nanofluids.