Blow Spinning of Polyimide/SiO₂ Composite Fibrous Sponges with Excellent Adsorption Capacity and Recyclability

Developing adsorption materials for organic solvents with both high adsorption capacity and recyclability provides a broad prospect for contaminated water treatment. In this study, PI/SiO2 composite nanofibrous sponges with hydrophobicity, high oil adsorption capacity, and excellent cycling performance fabricated by blow spinning have been reported. The improvement of hydrophobicity of PISi-3 was credited to the SiO2 nanoparticles, resulting in excellent oil adsorption capacity (103.95 g/g for ethanol, 320.99 g/g for motor oil, and 386.81 g/g for silicone oil). The recyclability after 10 cycles of PISi-3 was improved by 23% compared with the pure PI sponge owing to the supporting effect of SiO2 nanoparticles. Sponges with higher cycling performance could be obtained by regulating the temperatures of thermal treatment. PISi-3 after heat treatment at 450 °C exhibited good oil adsorption ability (98.12 g/g for ethanol, 261.92 g/g for motor oil, and 315.81 g/g for silicone oil) and excellent cycling performance. The adsorption capacity decreased by only 0.22% after 10 cycles. Therefore, the fabrication strategy of the sponges has great prospects in maritime oil spill recycling and industrial water treatment.