The Preparation And Properties Of Graphene Electrothermal Material

Since its discovery in 2004,graphene has been widely studied due to its extraordinary properties.In this paper,we did some research about its preparation and application,designed four kinds of film based on graphene,and then comes the procedure of transforming material to product.The main work we have done is listed as follows:1.The preparation of graphene film with large scaleUsing natural flake graphite with mesh 32 as raw material,the solution of graphene oxide was obtained through Hummers method,while the film was formed through self-assembly.The film was then transferred onto the glass plate,under the atmosphere of HI,the graphene oxide was reduced after 1h under the temperature of 95℃,its thickness could be precisely controlled(2-20μm)by adjusting concentration and self-assembly time.Finally,after clipping,the film was made into device,and could generate heat when charged with voltage of 5 or so within 3-5 seconds.2.The preparation of electrothermal material based on graphene(1)Organic conductive paperIt’s hard to get film when exerting pressure on graphene powder.In this part,we used cellulose as binder,conductive paper was obtained afterwards.The influence for intensity and appearance caused by stirring time and pressure were studied.Besides,resistance could be effectively adjusted by pressure.Finally,the product could produce heat steadily under different voltage.(2)Inorganic fiber paper based on grapheneDue to existence of lignin,it’s easy for organic paper to get fragile and yellow,which will lead to the reduction of properties.Besides,organic fiber is easily combustible,so it’s dangerous in most occasions.Hydroxyapatite is the main component of bone,it can be made into fiber under certain condition.In this section,we use oleic acid as the precursor,inorganic fiber can be easily obtained with hydrothermal method.Next,using GO and fiber as material,using ultrasonic and heating method,a compound can be prepared.Owing to the connection between fiber and GO,the material is flexible and hard to stretch.(3)Carbon nanotubes & grapheneCarbon nanotubes(CNTs)is a kind of material with high conductivity,when mixed with graphene,the CNTs was coated or stuffed between layer of graphene,which made the compound low resistance and high intensity.In this section,CNTs with uniform diameters and big length-diameter ratio were formed both on the surface and the inner pores of nickel foam by microwave-assisted heating method within 30 seconds,followed by sonication,CNTs can be easily departed from the frame of nickel.After that,mix GO with CNTs,thin film can be formed through suction,and the compound film can be obtained after reduction by HI.3.The electrothermal productIn this part,we developed different products aiming to different usage scenario,including low(45℃)and medium(80~100℃)temperature,these products include graphene conductive paper,graphene hand warmer,underfloor heating and electric drawing.We then tested its electrical properties and designed its circuit pattern,finally,the material was packed and product was thus produced.