Preparation And Evaluation Of Silver Coated Meta Aramid Fiber Paper

Meta-aramid fiber paper（MAFP）is widely used in electronic and electrical insulation parts and the aerospace industry due to its high strength,ultra-flexibility,flame retardancy and corrosion resistance.This paper proposes the use of low-temperature oxygen plasma treatment and electroless silver plating technology to prepare a silver-plated meta-aramid paper with insulating material as the substrate to achieve the purpose of obtaining an excellent durable conductive coating on a high-performance substrate.Firstly,the optimal process condition of low-temperature oxygen plasma treatment was studied by orthogonal and single factor tests.The results show that the silver-coated meta-aramid paper prepared at a nozzle speed of 1 m/min,a plasma cycle time of 80%and a nozzle height of 4～5 cm had the best conductivity,the highest silver content and the best washing and bending fastness.Then,through orthogonal and single factor tests,the effects of AgNO₃ concentration,glucose concentration,reaction temperature and reaction time on silver-coated meta-aramid paper were investigated.The research found that optimal electroless silver plating conditions were:20 g/L of AgNO₃,25 g/L of glucose,30°C of reaction temperature and 20hours of reaction time.The silver content of silver-coated meta-aramid paper was as high as 6.97%,and the sheet resistance was as low as 48.7 mΩ/sq.Subsequently,the mechanical properties,fastness and conductivity of silver-coated meta-aramid paper in high/low temperature,acid/alkali solutions and organic solvents were studied.The research shows that the break strength and elongation at break of silver-coated meta-aramid paper increased by 16.1%and 7.6%,respectively,the Young’s modulus decreased by 19.1%.The silver-coated meta-aramid paper still maintained excellent conductivity after 5 washing cycles,1000 bending cycles and soaking for 7 days in acid/alkali solution and organic solvents.The silver-coated has a sheet resistance of0.105～0.183Ω/sq between-80～200°C,and still maintains conductivity when exposed to ice and flame.Finally,the applications of silver-coated meta-aramid paper in electromagnetic shielding and electrical Joule heating were investigated.It was found that in the frequency range of 7.0～13.0 GHz,the electromagnetic shielding effectiveness of silver-coated meta-aramid paper can reach 95.47 dB,after soaking in acid/alkali solutions and organic solvents for 7 days,the electromagnetic shielding effectiveness of silver-coated meta-aramid paper still exceeded 60 dB.The silver-coated meta-aramid paper based electrical heaters can achieve human body warm（0.2 V）and relieve joint stiffness（0.3 V）with a low supplied voltage.The heater heated water from room temperature to 84°C with a supplied voltage of 1 V for 30 min,the efficiency of ice melting increased by 455%with a supplied voltage of 0.5 V.It provides a new exploration for electromagnetic shielding,personal thermal management and industrial heating in harsh environment.