para-Aramid Fiber Sheets for Simultaneous Mechanical and Thermal Protection in Extreme Environments

Abstract

First responders and military personnel require protection against multiple hazards. However, the structure of conventional materials only provides protection against a single threat. By combining a porous network with aligned fibers, this work demonstrates a multifunctional material with a high insulation and high ballistic resistance. Overcoming the limitations of conventional materials, this approach enables simultaneous thermal insulation and mechanical protection, serving as an ideal material platform for the design of high-performance protective equipment for aerospace and warfare applications.

From Space to Battlefield: A New Breed of Multifunctional Fiber Sheets for Extreme Environments

“…This behavior is often discussed in the context of the doping limits of semiconductors. 5 The group led by Hideo Hosono should be credited for articulating many transparent conductor design principles that we now take for granted. 6,7 They understood that in order to realize robust hole conduction in metal oxides, the upper valence band must be modified.…”

“…4 Recently, Gonzalez et al from the Parker lab at Harvard University succeeded in combining these two functionalities (mechanical and thermal protections) into one single, multifunctional material that allows reductions in both weight and complexity of multilayer protections (Figure 1). 5 They developed a porous structured sheet consisting of a single continuous fiber (para-aramid) that provides the mechanical protection comparable with the commercially available ballistic resistant fibers and significantly improved thermal insulation. They used the immersion Rotary Jet-Spinning platform, a dry-jet wet spinning method to obtain the porous interlocking structure of a single para-aramid fiber.…”

Wearable Aramid–Ceramic Aerogel Composite for Harsh Environment

“…The poly(p‐phenylene terephthalamide) or aramid (Kevlar) fibers could meet the harsh requirements of many cutting‐edge fields, including aerospace and aviation, electronics, and personal protective clothing, owing to its excellent integrated performances of super fatigue resistance, high specific strength, and thermal resistance. [ 6–10 ] Thus, aramid fibers have been widely used as a functional and structural material in protective applications. However, the aramid fibers serving as a thermal barrier in firefighter and first responder protective clothing cannot provide enough thermal protection due to its relatively high thermal conductivity and temperature‐sensitive polymeric nature.…”

Construction of Aramid Engineering Materials via Polymerization‐Induced para‐Aramid Nanofiber Hydrogel

“…[10] Therefore, a simplified approach for the direct production of all-PPTA 3D structures, including HCs, is needed.The developments of nanotechnology and hierarchical selfassembly for the preparation of bulk materials [17,18] inspire the rational bottom-up design approach for high-order structures of PPTA. In recent years, aramid nanofibers have been successfully prepared through several strategies, such as chemical cleavage, [19,20] immersion rotary jet-spinning, [21] and polymerization-induced selfassembly. [22] The emergence of aramid nanofibers greatly expands the PPTA application range.…”