Electrospun YSZ/silica nanofibers with controlled fiber diameters for air/water filtration media

Abstract

To develop electrospun ceramic nanofibers as water/air filtration media, it is important to control the fiber diameter. This is because the fiber diameter of the electrospun ceramic nanofibers determines the mean/largest pore sizes, and this governs the permeability and filtration efficiency. Herein, the content (or concentration) of ceramic precursors and polymeric binders was adjusted in the electrospinning solution to control the fiber diameter of electrospun yttria-stabilized zirconia (YSZ)/silica nanofiber. This can influence the viscosity of the electrospinning solution and directly affect the fiber diameter of the electrospun YSZ/silica nanofibers through the electrospinning process. Increasing the content of ceramic precursors sequentially confirmed that the fiber diameter of electrospun YSZ/silica nanofibers increases gradually. Conversely, adjusting the content of the polymeric binder could shift the overall distribution of the fiber diameters. In other words, it is more effective to reduce the content of polymer binder than to reduce the content of ceramic precursors to manufacture smaller fiber diameters. The polymer binder content plays a significant role in promoting the mean/largest pore sizes and filtration efficiency. The aim of this research was to develop the electrospun nanofibrous microfiltration (MF) membranes or high-efficiency particulate air (HEPA) filters for water/air remediation. To confirm this hypothesis, the associated characterizations were conducted to evidence the superior filtration performances. For example, a rejection rate (%) of 99.5% (0.5 μm polymeric particles) and a filtration efficiency of 99.9% (0.06 μm NaCl particles) were obtained to prove water and air filtration capacity, respectively.