PAN/PAN-FPU Double-Layer Composite Nanofiber Air Filter Fabricated by Electrospinning for Filtering Oil and Salt Particles

In modern society, the transport, manufacturing, and construction industries continuously release large amounts of oil and salt particles into the atmosphere. These particles can cause severe air pollution and pose health risks. However, it is difficult for most existing air filters to simultaneously have a high filtration efficiency for both salt and oil particles. Therefore, it is urgent to develop a highly efficient and low-resistance air filter membrane for the filtration of oil and salt particles. Herein, we prepared a double-layer composite nanofiber membrane (PAN/PAN-FPU) by electrospinning to manufacture high-efficiency air filters. The nanofiber membrane has the same overall thickness, and the thickness ratios of the fine and coarse fiber layers are 1:1, 1:2, 1:3, 1:4, and 1:5, where the thick fiber layer is PAN-FPU and the fine fiber layer is PAN. When the thickness ratio of the fine to coarse fiber layer is 1:3, the comprehensive filtration effect of the fiber membrane is the best. The filtration efficiency of the PAN/PAN-FPU nanofiber membrane for 0.075 μm salt particles is 99.84%, while the quality factor reaches 0.0391. The filtration efficiency of the PAN/PAN-FPU nanofiber membrane for 0.33 μm oil particles is 99.88%, while the quality factor reaches 0.0399. This study provides a basic model for a high-efficiency, low-resistance filter for filtering oil and salt particles.