Preparation Of Porous Carbon Composites Based On Melamine And Microwave Absorption Study

With the rapid development of communication technology,electromagnetic wave is more and more widely used in daily life.While the application of electromagnetic wave brings convenience to people,it inevitably affects the environment and human body,interferes with the normal operation of precision equipment,and electromagnetic wave absorbing materials are getting more and more attention from people.Traditional absorbing materials cannot adapt to modern complex electromagnetic environment due to their limited electromagnetic absorbing ability and poor environmental adaptability.Porous carbon materials can be regarded as composite materials composed of carbon matrix components and air components,which can effectively reduce density,adjust impedance matching,and have controllable pore size,pore structure and other excellent properties,so that it has become the main research direction of electromagnetic wave absorption materials.This paper mainly uses melamine foam as polymer carbon matrix to prepare new porous carbon absorbers.The main contents include:(1)Lightweight porous carbon absorber was prepared by directly carbonizing melamine foam.When the high temperature carbonization temperature is 800?,the minimum reflection loss value reaches-20.24 d B,the matching thickness is only1.8mm,and the loss mode is conductance loss.(2)The porous carbon/rGO and porous carbon/MXene composites were prepared by loading two-dimensional nanomaterial transition metal carbide Ti₃C₂ and graphene on melamine-derived porous carbon matrix.When Ti₃C₂T_X and rGO concentrations are 2 mg/m L and 8 mg/m L respectively,the minimum reflection loss is-27.23 d B and-33.66 d B,and the maximum effective absorption bandwidth is 4.42GHz and 3.74 GHz,respectively,under the combined action of conductivity loss and interface loss.(3)Magnetic porous carbon/MXene and magnetic porous carbon/rGO were prepared by loading rGO/Ni chain and MXene/Ni chain on melamine-derived porous carbon matrix respectively.When the Ni chain content is 0.1g and 0.15g,the minimum reflection loss is-31.29 d B and-41.77 d B,respectively,under the synergistic effect of one-dimensional Ni chain and two-dimensional MXene and rGO structures.The porous carbon absorber prepared by the above methods not only has good wave absorption,but also has excellent properties such as light weight,hydrophobic and flame retardant.It can meet the requirements of"light,wide band,strong absorption"of new absorbing materials,and provide a new idea for the preparation of low-cost,low density,light and efficient multifunctional electromagnetic wave absorbing materials.