Modification Of Graphite Nanosheets And Its Effect On Electrothermal Behaviors

The scientific research and engineering application of graphene products has become a hotspot for scientists and engineers to develop.Graphene electric products are the closest to market applications.Therefore,it is imperative to carry out this work.Electrothermal materials transform electric energy into heat due to the Joule effect.To date,resistive wires made of heavy metal alloys have primarily been used as the heat source in many appliances surrounding us.But the metal heating material is heavy,intolerant corrosion,smelting pollution and other shortcomings,need to find a new electric material to replace it.Graphite nanosheets(GNS)is not only excellent in conductive capacity,environment-friendly,but also has the advantages of low cost and high heat transfer efficiency.In addition,the thermal characteristics of graphite products also has a special effect of health care therapy,is very suitable for alternative metal into a new electric materials.But the graphite nanosheets is easy to agglomeration in the aqueous solution and not conducive to processing,needs to be a certain degree of modification.In this paper,an electrothermal film was prepared from graphite nanosheets as raw materials.The properties of the electrothermal films were analyzed.The effect of the modified films on the films was studied.Finally,the effects of the films were discussed.Graphite nanosheets were prepared by ultrasonic stripping using expanded graphite as raw material.The graphite nanosheets were used as the conductive filler and the sodium silicate solution as the film forming matrix.An inorganic electric film was prepared by intaglio printing method.The analysis of the electrothermal film revealed that it had a very high heat efficiency and conductivity,and the surface adhesion to the inorganic material was very strong,and the accelerated life test showed that it had a service life of more than 200,000 hours(22 years).Further studies have found that the conductivity of the film is proportional to the addition of the nanosheets.This result is consistent with the prediction of the percolation threshold model.The size of the film and the size of the nanosheets also affect the conductivity,Because they affect the probability of contact between the sheets.The effect of hydrothermal temperature,preoxidation and dispersant on the modification of graphite nanosheets was studied by hydrothermal method using titanyl sulfate as titanium source.The results of the analysis show that the surface of the graphite nanosheets produces a thin layer of large particles of titanium dioxide and has a chemical bond between the graphite nanosheets.Hydrothermal temperature at 140 ? has the best results,pre-oxidation can increase the site of titanium dioxide adhesion,resulting in a large number of large diameter 50 nm or more large particles;Sodium hexametaphosphate has a strong effect on the modification,which can make the modified product have a larger specific surface area.The modified nanosheets were prepared into an electrothermal film.Compared with the unmodified film,it was found that the film resistance after modification was redu ced from 34?to 19?And had a higher use temperature.In combination with the analysis of modified nanosheets,it was found that the enhancement of conductivity was a combination of three factors: Titanium dioxide particles prevent the nanosheet from stacking,the nanosheets from hydrophobic to hydrophilic and the dispersion of sodium silicate to titanium dioxide.