Functional Modification And Preparation Of Graphene-Based Membrane Materials

New carbon nanomaterials have gradually led humans into the"carbon materials era" due to its excellent physical and chemical properties.Graphene as a new carbon material has excellent electrical and thermal conductivity and large specific surface area,which makes it have great potential for industrialization and application prospects,and is currently under the spotlight of R&D teams around the world.The functional modification of graphene materials has become the focus of current scientific research.In this dissertation,starting from the functional modification of graphene,combined with the technical advantages of the preparation of membrane materials,three different graphene-based membrane materials were prepared.1.Firstly,α-Fe2O3 nanoparticles were loaded on the surface of graphene oxide(GO)sheets through hydrothermal method.Then the as-prepared α-Fe2O3@rGO sheets were deposited on polyacrylonitrile(PAN)nanofiber mat via vacuum filtration to obtain α-Fe2O3@rGO/PAN nanofiber composite membrane(NCM).The prepared NCM not only overcomes the aggregation of the nanoparticles,but also increases the specific surface area.As a membrane material,it is easy to recycling and reuse.The composition,morphology and structure of the NCM were characterized in detail.Photocatalytic experiments show that the NCM could effectively degrade a variety of organic dyes,among which the degradation rate of methylene blue(MB)was as high as 98.5%within 2 h.Moreover,the degradation rate still remained at high level after 5 cycles and the NCM remained intact,indicating the reusability of the NCM.It is in particular worth highlighting that high degradation efficiency was obtained even under natural sunlight,demonstrating great potential applications of the NCM in industrial dye wastewater treatment.2.GO homogeneous films was moderately and accurately reduced in merely one step laser direct writing,and a certain thickness can be reduced forming the GO/rGO Janus films.The structure and chemical composition of GO/rGO films prepared by laser direct writing were characterized.The actual effect of the response to ambient temperature and humidity is determined experimentally.The response performance of Janus films with different thickness was tested,and the 15 μm Janus film was the best.Using the unique response ability,Janus films were made into different kinds of actuators and all of them show good prospects for application.3.By constructing protrusions on the GO film by laser direct writing and chemical reduction by hydrogen iodide(HI),an rGO film with 3D structure was prepared as a wearable pressure sensor.In this project,the 3D structure of the prepared rGO film was characterized by SEM,and a simple electrode template was made to test its pressure sensing performance.In addition,two kinds of wearable pressure sensors were fabricated by the flexible 3D structured rGO film.