PAA@ZIF-8 incorporated nanofibrous membrane for high-efficiency PM_2.5 capture

With growing concerns over air quality in many countries around the world, metal–organic frameworks are now being widely researched for its application in developing air filtration technology for PM_2.5 removal. Our study reports the successful fabrication of a polyacrylic acid @zeolitic imidazolate framework-8 (PAA@ZIF-8) membrane using electrospinning technology which shows great promise for PM_2.5 filtration. Our PAA@ZIF-8 membrane had a small pore size at 0.5 µm with a porosity of 89.4%, and after modification by ZIF-8, the PAA@ZIF-8 membrane gained porous rough nanofibers, positive surface zeta potential, and high tensile strength. Our tests confirmed the PAA@ZIF-8 membrane's high potential for PM_2.5 filtration over commercial PVDF and electrospun PAA membranes, recording a PM_2.5 retention rate of 99.6%. Besides its small pore size, the PAA@ZIF-8 membrane's rough and porous nanofiber structure created a high BET surface area (344.9 m²/g) which physically adsorbs the PM_2.5 particles. Additionally, we found that the positive surface zeta potential (67.3 mV at PH = 7) of the ZIF-8-coated nanofibers attracts negatively charged PM_2.5 particles combined in air moisture, thereby further improving the PM_2.5 filtration rate.