Facile and Novel Eco-Friendly Poly(Vinyl Alcohol) Nanofilters Using the Photocatalytic Property of Titanium Dioxide

Abstract

This study aimed to develop a highly efficient nanofilter for capturing fine particles using electrostatic forces. Poly(vinyl alcohol) (PVA), a water-soluble synthetic polymer, was selected as the main component of the filter because it can be easily fabricated by electrospinning. Titanium dioxide (TiO 2 ) nanopowder with an anatase structure was applied to the nanofilters as it has the highest photocatalytic activity among the existing photocatalysts. PVA nanofilters fabricated by electrospinning could still be dissolved in water by hydrolysis. Therefore, heat treatment was performed to make the nanofilters stable, thereby forming CO bonds by keto−enol tautomerization. Structural changes in the PVA nanofilter before and after heat treatment were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analysis. As the TiO 2 concentration increased, the fiber diameter of the PVA nanofilter decreased and a homogeneous fiber was obtained. The filtration efficiency and pressure drop also improved significantly, compared to those of the PVA-only nanofilter. Moreover, we observed eco-friendly decomposition of the PVA/TiO 2 nanofilter into water and carbon dioxide by a photocatalytic reaction under UV irradiation.

Synthesis of Amid-MCM-41-SO3H Electrospun Nanofiber Mat: Candidate for Trapping of Microorganisms

“…According to our previous work [25][26][27], for the synthesis of MCM-41─SO 3 H, tetraethyl orthosilicate (TEOS) (7.0 mL), 3-mercapto propyl Triethoxysilane (MPTMS) (5.0 mL), NaOH (0.9 g) and NaF (0.19) were used. The Cetyltrimethylammonium bromide (CTAB) (8.0 g) was used as template and And removed at the end of the synthesis process by solvent extraction.…”

Advanced Design of Fiber-Based Particulate Filters: Materials, Morphology, and Construction of Fibrous Assembly

“…Polylactic acid (PLA) is a bio-derived and biodegradable polyester, and its applicability as a filter material has been studied [ 97 , 108 , 111 , 112 ]. Likewise, PVA was studied as a biodegradable filter material [ 176 ].…”

Fabrication of a High-Performance and Reusable Planar Face Mask in Response to the COVID-19 Pandemic

“…To meet the critical and intensifying demand for masks, researchers and industry professionals have made great efforts to address the mask shortage and to enhance the protection afforded by existing masks [11] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] . These efforts include ① developing alternative materials with sufficient filtration efficiency [26] , [27] , [28] ; ② developing and engineering multifunctional masks with hydrophobic, antimicrobial, and self-disinfecting properties [29] , [30] , [31] ; ③ optimizing the design of masks for better protection, breathability, and user comfort [32] , [33] , [34] , [35] ; and ④ exploring new technologies for the efficient production and customization of masks, such as three-dimensional (3D) printing [36] , [37] , [38] , [39] , [40] , [41] . Even so, as newly reported cases of COVID-19 are increasing sharply to approximately 0.5 million per day [1] , a huge demand for face masks and personal protective equipment (PPE) is expected for the winter in the northern hemisphere.…”