Superstrong Alginate Aerogels

Abstract Sodium alginate (SA) aerogels have received extensive attention in environmental modification, energy‐related systems, and thermal insulation due to their good processability, nontoxicity, and biodegradability. However, achieving superior mechanical properties remains a significant challenge for SA aerogels as engineering materials. In this work, superstrong SA aerogels are prepared via an effective in situ crosslinking method, consisting of ice‐templated preassembly followed by a specially designed dissolution process in mixing GDL/EtOH/H 2 O (δ‐glucolactone/ethanol/water) solution. Upon optimization of heat and mass transfer during the ice dissolution process, along with the unique ice template effect, a homogeneous, highly crosslinked, and long‐range oriented structure in high‐solid fraction SA matrices is obtained. The resultant SA aerogels (248.0 ± 4.4 mg cm −3 ) exhibit an outstanding specific modulus of 1.45 ± 0.15 GPa cm 3 g −1 ( E = 360 ± 32 MPa, σ y = 14.8 ± 0.8 MPa), remarkable energy absorption capability (32.1 ± 4.4 kJ kg −1 ), and considerable thermal insulation performance (0.044 ± 0.007 W m −1 K −1 ). The present strategy paves a way for the fabrication of high‐performance SA‐based engineering materials with well‐oriented microstructures and superior multifunctionality.