PAN/FPU Composite Nanofiber Membrane with Superhydrophobic and Superoleophobic Surface as a Filter Element for High‐Efficiency Protective Masks

Abstract

Recently, because of the outbreak of COVID‐19, the demand for various types of filter elements in protective materials has increased globally. Furthermore, new requirements for the filtration performance of PM2.5 liquid (oil) particles have been put forward. In this work, Superhydrophobic and superoleophobic composite nanofibers with excellent filtration capacity for oil and salt particles are developed through the modification of polyacrylonitrile (PAN) by fluoro‐polyurethane (FPU) doping. The results show that the PAN/FPU composite nanofibers doped with 9 wt% FPU has a uniform fiber morphology with a diameter of 240 ± 30 nm. Compared to the pure PAN nanofibers, the water‐based contact angle of PAN/FPU increases from 90 ± 5° to 151 ± 5°, and the oil‐based contact angle increases from 58 ± 2° to 152 ± 3°. Importantly, at a high flow rate of 95 L min−1, the filtration efficiency of the PAN/FPU nanofiber membrane for 0.3 µm oil particles increases from 92 ± 1% to 99.2 ± 0.1%. After cyclic loading, the filtration efficiency of 0.3 µm oil particles remains above 98%. Meanwhile, the filtration efficiency for 0.3 µm salt particles remains at 98.23 ± 0.1%. The PAN/FPU nanofiber membrane developed in this work is effective in applications and has good market prospects as a protective filtration material.

Polystyrene/Fluorinated Polyurethane Electrospinning Nanofiber Membranes Incorporated with Graphene Oxide–Halamine as Mask Filter Materials for Reusable Antibacterial Applications

“…As the GO content increased, and the solution viscosity decreased, which is due to the decrease of intermolecular cohesion, which favors the stretching of the electric field force and leads to the thinning of the nanofiber diameter (Figure 2g). 29 After introducing GO−GH to PS/FPU, the pore size decreased significantly to 0.6−1.1 μm (Figure 2i). The porosity increased from 92.26 to 98.18% (Figure 2h).…”

“…First, PS (10 g), TBAC (0.15 g), and DMF were stirred for 300 min. Thereafter, FPU (10 wt %) was added to the PS solution according to our previous method . Finally, GO–GH (1 wt %) and the PS/FPU solution were mixed for 10 h at 65 °C.…”

“…The filtering performance and cyclic loading performance of materials were performed by a TSI8130 automatic filter-material detector according to our previous research methods. ,− The PM 2.5 cyclic purification capacity of membranes was tested using a custom-designed device according to a published method. , …”

“…Thereafter, FPU (10 wt %) was added to the PS solution according to our previous method. 29 Finally, GO−GH (1 wt %) and the PS/FPU solution were mixed for 10 h at 65 °C. The PS/FPU/GO−GH nanofiber membrane was prepared using electrospinning technology with a spinning voltage of 22 kV, spinning distance of 18 cm, and feeding speed of 0.08 mL/min.…”

“…Li et al 28 found that the hydrophilicity, mechanical properties, and biocompatibility of the poly(L)-lactide nanofibers was enhanced by incorporating reduced graphene oxide. In a preliminary study, 29 we modified polyacrylonitrile by doping it with fluorinated polyurethane (FPU) to develop a super-oleophobic nanofiber membrane, and its filtration efficiency for oily particles was more than 99%. Numerous studies have focused on antibacterial nanofiber filter materials.…”