Tuning The Microwave Absorption Property Of 2D Transition Metal Carbide(MXene) And The Electromagnetic Interference Shielding Performance Of Its Composite

The increasing use of electronic products in life has brought convenience to life,but it has also brought electromagnetic pollution.Electromagnetic interference not only affects the normal use of equipment,but also endangers human health.In order to reduce electromagnetic interference,microwave absorption(MA)and electromagnetic interference(EMI)shielding materials are produced.The development of electronic equipment requires both MA and EMI shielding materials to be"thin,light,wide and strong".Because of the Low density,high electrical conductivity and large specific surface area,Two-dimensional transition metal carbides has received a lot of attention in the field of MA and EMI shielding.This thesis is based on the Ti₃C₂T_xMXene,MA property of different ion intercalation Ti₃C₂T_xmaterial and the EMI shielding property of Ti₃C₂T_x/Si O₂composite are studied.The main research contents and conclusions are as follows:(1)Different ion intercalation Ti₃C₂T_xare prepared and their MA property is tested.High-purity layered Ti₃C₂T_xis obtained by HF etching Ti₃Al C₂and using NH₃·H₂O,N₂H₄·H₂O,Na OH solution intercalate Ti₃C₂T_x.XRD and XPS results indicate that ion intercalation increases the Ti₃C₂T_xlayer spacing and generates Ti O₂.In the frequency range of 2-18 GHz,Ti₃C₂T_xachieves a minimum RL(reflection loss)of-23.6 d B at a thickness of 3.8 mm,N₂H₄·H₂O-Ti₃C₂T_xand NH₃·H2O-Ti₃C₂T_xachieves a minimum RL of-31.3 d B and-30.4 d B,respectively,at a thickness of 2.1 mm.Na OH-Ti₃C₂T_xachieves a minimum RL of-21.8 d B at a thickness of 2.5 mm.The ion intercalation Ti₃C₂T_xattenuates electromagnetic waves by resonance loss.(2)Ti₃C₂T_x/Si O₂composite are prepared and their mechanical and EMI shielding property are tested.Ti₃Al C₂is etched by HF which is in-situ generated by Li F+HCl.Ti₃C₂T_xnanosheet is obtained by hand shaking.The mesoporous silica FDU-12 which have high sintering activity is used as matrix,Ti₃C₂T_xand FDU-12 are composited by heterogeneous deposition and the composite is sintered at a low temperature of 950°C.XRD and SEM results indicate that Ti₃C₂T_xis oxidized at high temperatures but still maintains a lamellar structure.The SE_Tvalues(Shielding effectiveness)of 1wt%Ti₃C₂T_x,5wt%Ti₃C₂T_x,and 10wt%Ti₃C₂T_xin the K-band(18-26.5 GHz)achieve 6.2 d B,16.9 d B,and 27.6 d B,respectively.The shielding effectiveness of Ti₃C₂T_x/Si O₂composites is due to the surface reflection and internal multiple reflection caused by the high conductivity of Ti₃C₂T_x.In this thesis,different ion intercalation Ti₃C₂T_xMA materials and Ti₃C₂T_x/Si O₂EMI shielding materials are prepared.They have good MA and EMI shielding properties and we propose the electromagnetic wave attenuation mechanism.This work is a useful exploration for ion intercalation to adjust the absorption property of Ti₃C₂T_xand application of structure-function integrated Ti₃C₂T_xcomposite.