The Preparation And Performances Of MXene-based Electromagnetic Shielding Textiles

With the development of electromagnetic shielding materials in recent years,a large number of research results have emerged in the fields of electromagnetic shielding polymer composites,membrane materials and three-dimensional structural materials.In order to provide electromagnetic protection for human body and flexible electronic devices,flexible and wearable electromagnetic shielding materials need to be developed urgently.In this thesis,with the help of MXene,a new two-dimensional conductive nano-material,commercial textiles are endowed with conductivity,which realizes the functionalization of traditional textiles and shows excellent electromagnetic shielding performances.The specific research contents and innovative achievements of this thesis are as follows:(1)The conductive few-layer Ti3C2Tx MXene nanosheet dispersions are obtained successfully by etching and delamination of Ti3AlC2 in LiF/HCl system,and their assemblies with polypyrrole(PPy)and polyaniline(PANI)are successfully realized.On the one hand,PPy nanoparticles are directly in-situ polymerized in MXene dispersions without any initiator,and decorated at the edges or defects of MXene sheets to form PPy/MXene conductive ink.On the other hand,the uniform and stable PANI nanowire dispersions are successfully prepared according to the rapid mixing,and assembled with MXene to form PANI-MXene conductive coating.(2)Using the simple and time-saving dip-coating method,the textiles are directly immersed in PPy/MXene conductive ink and then water-resistant ink in turn.Finally,the water-resistant,cold-proof and anti-electromagnetic interference multifunctional textiles are prepared.The introduction of PPy not only enhances the interaction between nanosheets and substrates,but also introduces a large number of polar functional groups and interfaces,so that the electromagnetic shielding effectiveness of the textile with thickness of 0.42 mm and conductivity of 1000 S/m reaches 42 dB.In addition,the water contact angle of the textile reaches above 140°,and shows the characteristic of water resistance.After connected with low-voltage power supply,the textile also shows the Joule heating performance,which can achieve the function of cold protection and warmth preservation.(3)By analyzing the rheological properties,PANI nano wire dispersions and MXene nanosheet dispersions are alternately sprayed on the fabrics forming PANI-MXene conductive coating,and the conductive fabrics with response performances to acid-alkali atmosphere are obtained successfully.The electromagnetic interference shielding performance of the fabrics with low PANI-MXene content can meet the commercial requirement of 20 dB.When the fabrics meet the alkaline atmosphere,the electrical conductivity suddenly decreases,with the decline of shielding performance at the same time,so that the acquisition of electromagnetic signals can be realized again.In addition,the textiles show the function of real-time detecting acid-alkali atmosphere.