Preparation Of Aramid-based Flexible Conductive Composites And Its Performance Study

A single material is often not sufficient when conflicting properties need to be combined,or when different variations in properties are required in different areas of the material.Flexible conductive composites are a relatively new class of materials that use a flexible material as a substrate and embed a conductive material into the surface or inside to make it conductive.Flexible conductive composites include polymer films,paper-based materials,textiles,etc.While conductive materials mainly include graphene,conductive metals,conductive polymers,etc.The composition,microstructure and properties of flexible conductive composites can be systematically tailored to a particular party,showing a wide range of applications and prospects in many fields such as electromagnetic shielding,supercapacitors,nanogenerators,sensors and heaters.However,it is still a major challenge to prepare flexible conductive composites with multiple functions such as optical,electrical,thermal and magnetic using a greener,environmentally friendly and simple process.Therefore,this paper selects aramid materials with excellent properties such as high modulus,good thermal stability,light weight,acid and alkali resistance as the matrix phase and adopts green and environmentally friendly magnetron sputtering and laser scribing techniques to prepare aramid-based flexible conductive composites,respectively,and systematically investigates their properties and explores their applications in different fields.Specific studies include.（1）Conductive aramid paper（Ag/AFP）was prepared by depositing silver on the surface of para-aramid（PPTA）fiber paper using a combination of plasma treatment and magnetron sputtering.The resistance of the Ag/AFP film can be effectively adjusted by varying the sputtering time,thus imparting controlled electrical heating properties to Ag/AFP.The Ag/AFP（thickness of 0.03 mm）obtained by sputtering modification for6 min reached 120°C in an ultra-fast response time of 5.5 s at an applied voltage of 1.2V,exhibiting excellent electrical heating performance,mainly due to the high conductivity of the continuous uniform dense Ag coating.Meanwhile,the ultra-thin,uniform,solid and dense Ag coating enables Ag/AFP to exhibit excellent electrical conductivity stability during both repeated bending and stretching.In addition,Ag,as a dual conductive and antimicrobial particle,imparts electrical heating properties to the aramid paper while also making Ag/AFP have good antimicrobial properties.Ag/AFP was applied to manufacture ultra-flexible antimicrobial thermal therapy patches and showed good thermal therapy results.Compared with other flexible film heaters,the preparation process of Ag/AFP is green and environmentally friendly as well as the utilization of conductive metal coating and easy to mass produce.This part of the study provides a theoretical and experimental basis for the practical application of aramid-based wearable heaters in next-generation health thermal management and protection.（2）Laser-induced graphene（LIG）was formed on the surface of Kevlar woven fabric（1500D）by laser scribing technique,and then nickel nanoparticles（Ni NPs）were deposited on the surface of LIG by magnetron sputtering technique to prepare Ni NPs/LIG with photothermal conversion performance.Ni NPs/LIG has excellent photothermal performance,while the warp and weft compilation structure of plain aramid fabric and the porous structure formed after laser scribing provide a good water transport path for seawater evaporation,which makes it possible to be applied in solar desalination.Compared with simple LIG,the addition of Ni NPs with plasma effect can effectively reduce the heat loss due to light reflection of graphene itself,enhance light absorption,and efficiently achieve photothermal conversion,and the evaporation rate of water can reach 1.608 kg·m^-2·h^-1 under 1 sunlight irradiation（100 m W/cm²）,with a conversion rate of 93%.In addition,Ni NPs/LIG formed a stable superhydrophobic structure on the fabric surface,which effectively prevented the salt deposition during desalination.More importantly,compared with conventional solar desalination materials,Ni NPs/LIG has superb antibacterial properties,which can reduce the adhesion of bacterial biofilm on the material surface.Therefore,Ni NPs/LIG has multiple water purification potential in desalination and is expected to be a promising desalination material.In this paper,a series of aramid-based flexible conductive composites were prepared using green processing methods matching the structural properties of different aramid-based materials,and their applications in medical thermal therapy patches and desalination were explored,providing new ideas and experimental basis for the development of aramid-based flexible conductive composites.