Carbon nanotube (CNT) hybrid composites were formed by combining a CNT and silicone elastomer solution with Kevlar yarn, Kevlar fabric, and Kevlar veil materials. The integration of a CNT-silicone matrix with Kevlar yarn and fabric materials produced a composite with moderate electrical and thermal conductivity due to CNT fabric combined with the strength of Kevlar fabric or yarn. In the material synthesis, a notable difficulty was that the CNT-silicone did not bond strongly to the Kevlar. The composites passed the Vertical Flame Test ASTM D6413 and the Forced Air Oven Test NFPA 1971. These hybrid composites can have multiple applications in areas requiring favorable conductivity, strength, and flame and heat resistance. The application areas include firefighter apparel, military equipment, conductive/smart structures, and flexible electronics. The synthesis process used to manufacture CNT-silicone/Kevlar composites yielded composite sheets with an area of 2250 cm2. The process is scalable and customizable for the synthesis of CNT composites with tailored properties. Improvements in the bonding of CNT-silicone to Kevlar are being investigated.
Kevlar fabrics have high strength, high modulus, and high impact resistance, and they can withstand high temperatures [ 41 43 ]. The new developments in CNT/Kevlar composite fabrics provide excellent composite strength, modest electrical conductivity, and high flame resistance. There can be a wide range of applications for such textiles in the areas of defense, automobile/aircraft structures and components, functional textiles, firefighting and insulation, etc. They can also be useful for printable electronics and thermal management of electronic devices. Looking at the applicational opportunities that CNT/Kevlar composites could provide, we have developed three variations of composites: CNT-silicone/Kevlar yarn, CNT-silicone/Kevlar fabric, and CNT-silicone/Kevlar veil. Over the years, CNT composites with different polymers, metals, and ceramics have been developed for different applications, including aerospace, biomedicine, electromagnetic interference shielding, supercapacitors, functional textiles, and many more [ 20 26 ]. Studies have also demonstrated the capacity of CNT composites to improve friction and wear behavior in equipment and parts [ 27 29 ]. With the improved synthesis procedures, researchers have been able to synthesize large-scale CNT composites, including pristine CNT sheets and tapes [ 30 35 ]. CNT composites with cotton and spandex have been studied for dyeable, wearable, and shielding applications [ 30 37 ]. Researchers have shown that some application areas of CNT/Kevlar composites improve ballistic performance, wearable electronics, fabrics with anti-impact properties, textiles with sensing capabilities, and triboelectric nanogenerators [ 38 40 ]. The CNT/Kevlar composites for those applications were developed by soaking pieces of Kevlar fabric in CNT using ultrasonic dispersion and impregnation methods [ 38 40 ]. To our knowledge, macroscale and continuous synthesis of CNT/Kevlar composites have not yet been reported. Nanoelectronics,…