Double-network silica–polyacrylamide composite aerogels with enhanced mechanical integrity and multifunctional adsorption performance

A facile strategy was developed to synthesize silica/polyacrylamide composite aerogels that simultaneously exhibit high mechanical strength and large surface area. An interpenetrated organic polyacrylamide network was incorporated within the silica framework without additional cross-linkers, enabling efficient stress distribution and enhanced structural integrity. The optimized TDB-Pam(2 M) composite aerogel possesses a homogeneous mesoporous network with a specific surface area of 774 m 2 g -1 , low density (0.346 g cm -3 ), and superior compressive strength (22.3 MPa) with a Young’s modulus of 25.3 MPa. The incorporation of amide-rich polyacrylamide also provided selective binding sites for heavy-metal ions, achieving more than 90% Hg 2+ removal efficiency and a Langmuir maximum adsorption capacity of 626.79 mg g -1 for TDB-Pam(2 M). This synthesis route provides an effective approach to fabricate mechanically reinforced, multifunctional silica-based aerogels applicable to environmental purification and other advanced porous-material applications.