Visible Microfluidic Deprotonation for Aramid Nanofibers as Building Blocks of Cascade‐Microfluidic‐Processed Colloidal Aerogels

Abstract

Aramid nanofibers (ANFs) have played a significant role in fabricating advanced materials. However continuous and efficient preparation of homogeneous ANFs remains challenging. Herein, a microfluidic deprotonation approach is proposed for the first time to realize continuous, scalable, efficient, and uniform production of ANFs by virtue of large specific surface area, high mixing efficiency, strong heat transfer capacity, narrow residence time distribution, mild laminar‐flow process and amplification‐free effect of the microchannel reactor. By means of monitoring capabilities endowed by the high transparency of the microchannel, the kinetic exfoliation process of original aramid particles was in situ observed and the corresponding exfoliation mechanism was established quantificationally. The deprotonated time can be reduced from traditional several days to 7 minutes for the final colloidal dispersion due to the synergistic effect between enhanced local shearing/mixing and the rotational motion of aramid particles in microchannel revealed by numerical simulations. Furthermore, the cascade microfluidic processing approach was used to make various ANF colloidal aerogels including aerogel fibers, aerogel films and 3D printed aerogel articles. Comprehensive characterizations show that these cascade‐microfluidic‐processed colloidal aerogels have identical features as those prepared in batch‐style mode, revealing the versatile use value of these ANFs. This work achieves significant progress towards continuous and efficient production of ANFs, bringing about appreciable prospects for the practical application of ANF‐based materials and providing inspiration for exfoliating of any other nano‐building blocks.This article is protected by copyright. All rights reserved