A Comparative Study: Unveiling the Nanomorphology Evolution and Fibrillation Pathways in Deprotonation vs Proton-Coupled Deprotonation for High-Efficiency Aramid Nanofiber Synthesis

Abstract Aramid nanofibers (ANFs) are promising high-performance nanoscale building blocks, yet their application is hindered by the time-consuming conventional deprotonation method. This study systematically compares this traditional method with a proton donor-coupled deprotonation (PCD) strategy. While both preserve the core chemical structure of PPTA fibers, the PCD approach, by incorporating a proton donor, dramatically alters the reaction kinetics and nanofibrillation pathway. Comprehensive characterization confirms that it accelerates exfoliation from days to 4 h, yielding a highly transparent dispersion. Crucially, the synthesis pathway dictates the final nanomorphology: conventional ANFs form rigid networks with larger pores (∼44 nm), whereas PCD-derived ANFs are more interconnected and pliable, self-assembling into denser membranes with finer pores (∼9 nm). This structural divergence translates to superior integrated mechanical performance, with PCD-ANF membranes exhibiting a remarkable balance of high tensile strength (115.14 MPa) and good ductility (19.27%), alongside fully retained inherent flame retardancy. This work establishes fundamental structureproperty relationships, demonstrating that the choice of nanofibrillation mechanism is a powerful tool for tailoring nanoscale architecture in advanced functional materials.