Fig. 5: Large-size, continuous aramid aerogels prepared by EM strategy.

a Photos of large-size (50 × 50 cm) free-standing aramid colloidal aerogel films with density of 52.6 mg cm−3. b Photos of free-standing roll-to-roll gel film device. ANF: aramid nanofiber. c SEM images of roll-to-roll layered aramid colloidal aerogel films. d Amplified SEM images. e Continuous aramid colloidal aerogel film with density of 48.5 mg cm−3 over 20 m in length and approximately 100 μm in thickness. f Diagram of roll-to-roll preparation of EM conformal aramid colliodal gel films on conductive films with microstructures. (i) conductive stainless steel coil, (ii) EM conformal sol-gel transition, (iii) collection of conformal aramid colliodal gel films.