In-situ polymerization of PANI nanocone array on PEN nanofibrous membranes for solar-driven interfacial evaporation

Abstract

Solar-driven interfacial evaporation (SDIE) holds great potential for desalination, but it also poses challenges to application performance. Herein, a novel polyaniline (PANI) modified polyarylene ether nitrile (PEN) electrospun nanofibrous membranes (PANI@PEN) was developed by introducing PDA and CTAB, which increased the polymerization amount of PANI and controlled its morphology by sequential in-situ polymerization, aiming to enhance its SDIE comprehensive performance. This unique structure can generate multiple diffuse reflections under sunlight, resulting in the highest water evaporation rate of the nanofibrous membrane at 1.822 kg m−2 h−1, while evaporation rate at 1.527 kg m−2 h−1 for a 3.5 wt% sodium chloride solution. Due to the good flexibility of PEN polymer substrate, the obtained membranes can be easily arched, showcasing an interesting ability to collect salt through salt deposition. Meanwhile, PEN also provides a robust skeleton, endowed PANI@PENs with corrosion-resistant, capable of desalination in acidic media, purifying heavy metal ion solutions through evaporation, as well as good mechanical properties for reusability. The study potentially provides a strategy for utilizing dopamine and CTAB loaded on high-performance polymer nanofibrous membranes and the convenient in-situ polymerization to generate advanced photothermal PANI. This strategy paves a way to enable high-performance engineering polymer, PEN, with solar-thermal evaporation capabilities, further opening its potential applications in seawater desalination and industrial wastewater purification.