Multifunctional 2D Polymeric Nanofiber Networks via Proton-Mediated Assembly for High-Temperature Applications

Abstract Advanced heat-resistant nanofibrous networks are attracting growing attention as critical functional components owing to thermostable porous architectures and selective sieving capabilities that offer reliable safeguards and a technical foundation to ensure safe operation and sophisticated manufacturing in harsh thermal environments. However, the high glass transition temperature and narrow processing window of heat-resistant polymers limit processing accuracy, making it difficult to achieve nanoscale processing of fibers and regulation of their assembled architectures, thereby causing a conflict between the heat resistance advantage and structural functionalization. Here, we report a universal proton-mediated intermolecular interaction regulation strategy for regulating the self-assembly pathway and morphology of heat-resistant nanofibers without dependence on melting or dissolution, to fabricate two-dimensional (2D) thermally reliable nanofiber networks (TR-nets) with fine separation function. By customizing the nanofiber dispersion properties and electrospraying process parameters, we couple the assembly of nanofibers mediated by proton transfer with the 2D deformation of nanofiber dispersion microdroplets sprayed from a Taylor cone, thereby manipulating the dominant intermolecular interactions to dynamically switch between repulsion and attraction in the 2D plane, regulating the topological assembly behavior of nanofiber building blocks. Benefiting from the hydrophobic porous Steiner network architecture and intrinsic material thermal stability, the fabricated TR-nets exhibit multifunctionality combining liquid repellency, air permeability, dust prevention, and sound transmission, and can withstand high-temperature environments up to 400 °C. This work may afford innovative perspectives for the advanced design and development of functionally integrated devices capable of working in high-temperature environments.