Photothermal-Responsive and Flame-Retardant CB/APP/PNIPAM Electrospun Composite Membrane for Efficient Oil-Water...

Multifunctional membranes with rapid responsiveness and high fire safety are highly desirable for oil-water separation, yet integrating photothermal responsiveness, thermoresponsive wettability, and flame retardancy into a single membrane remains challenging. Herein, a multifunctional CB/APP/PNIPAM@PP composite membrane was successfully fabricated on a polypropylene (PP) nonwoven substrate via a facile one-step electrospinning strategy. The membrane exhibits reversible wettability switching from superhydrophilicity (∼0° at 20 °C) to hydrophobicity (119° at 60 °C) owing to the lower critical solution temperature (LCST) behavior of PNIPAM. Under one-sun irradiation, the membrane temperature rapidly increased to approximately 66 °C within 420 s, enabling photothermal regulation of surface wettability. Meanwhile, the limiting oxygen index increased from 16.1% for pristine PP to 26.3%, indicating significantly improved flame retardancy. The membrane also exhibited adsorption capacities of 8.49-31.58 g g-1 toward various oils and organic solvents and achieved separation efficiencies above 95% for different surfactant-stabilized water-in-oil emulsions. This work provides a simple strategy for integrating photothermal responsiveness, thermoresponsive wettability, flame retardancy, and oil-water separation into a single electrospun membrane, demonstrating its potential for multifunctional oil-water separation applications.