Hierarchically Structured All-biomass Air Filters with High Filtration Efficiency and Low Air Pressure Drop Based on Pickering Emulsion

Abstract

Although a high-efficiency air filter can be achieved from electrospun nanofabrics, it has been challenging to reduce the pressure drop, increase the filtration capacity, and improve the production rate of the electrospinning process. Here, we report a hierarchically structured all-biomass air filter with high filtration efficiency and low air pressure drop based on applying Pickering emulsions to generate proteinfunctionalized nanostructures. Specifically, the air filter consists of cellulose nanofibers (CNF)/zein nanoparticles as active fillers prepared from Pickering emulsions and porous structures of microfibers as the frame from wood pulp (WP). The zein-protein-coated nanoparticles, CNF/zein, contribute in multiple ways to improve removal efficiency of the filters. First, the exposed functional groups of zein-protein help to trap air pollutants including toxic gaseous molecules via interaction mechanisms. Second, the nanoparticles with a high surface area promote the capture capability for small particulate pollutants. Meanwhile, the long-micron WP fibers forming a frame with large pores significantly reduce the pressure drop. Via adjusting the component ratios of in the Pickering emulsion, we report an optimized air filter with the high efficiency for capturing both types of pollutants: particulate matter (PM) and chemical gasses such as HCHO and CO, and the extremely low normalized pressure drop, that is, approximately 1/170 of the zein-based nano air filter by electrospinning. This study initiates a cost-effective strategy for forming a hierarchical nano-and microstructure, enabling high efficiency of capturing particulate pollutants of a wide size range and more species. More significantly, this is the first study in which Pickering emulsion is applied as a critical approach with integration of bio-and nano-technology to make high-performance, green air filters.

Zein‐based microcapsule for vanillin sustained release

“…Compared to many animal‐source proteins, zein is cheaper, more biocompatible, more biodegradable and more thermal resistant 11 . Therefore, Zein has been to one of the most extensively investigated natural ingredients to encapsulate hydrophobic compounds 12,13 . In recent years, researchers have paid more attention to the practical application performances of zein‐based microcapsules.…”

“…11 Therefore, Zein has been to one of the most extensively investigated natural ingredients to encapsulate hydrophobic compounds. 12,13 In recent years, researchers have paid more attention to the practical application performances of zeinbased microcapsules. For example, in the research of Liu et al, zein/fucoidan composite nanoparticles were fabricated for the delivery of pterostilbene, a hydrophobic nutraceutical with diverse beneficial biological activities.…”

Effect of different drying methods on zein‐based microcapsules loaded with Artemisia argyis essence obtained by anti‐solvent precipitation

“…However, zein amphiphilic property is a driving force for self‐assembly into micro‐ or nanoparticles, which have been extensively investigated for their potential as delivery systems for bioactive compounds 3 . As a carrier, zein can deliver both hydrophilic and encapsulated lipophilic materials, which has great potential application in the coating of food and medicine industry 4–6 . In fact, zein has been used as carrier of a variety of functional materials, including quercetagetin, thymus, and curcumin 7…”

Fabrication and Characterization of Highly Oriented Composite Nanofibers with Excellent Mechanical Strength and Thermal Stability

“…Moreover, the emergence of nanotechnology has further broadened the applied range of fiber materials, mainly attributing to the super high specific surface area, high porosity caused by the refinement of fiber diameter, which greatly improves the performance of fiber materials 3–5. At present, electrospinning technology has become one of the main ways to effectively prepare nanofibers due to the advantages of simple manufacturing equipment, low cost, controllable process and various kinds of spinnable materials 6–9. Besides, the electrospun nanofibers are of controllable structures and components as well as unique functionalities and well received by the researchers 10–12.…”

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At present, electrospinning technology has become one of the main ways to effectively prepare nanofibers due to the advantages of simple manufacturing equipment, low cost, controllable process and various kinds of spinnable materials. [6][7][8][9] Besides, the electrospun nanofibers are of controllable structures and components as well as unique functionalities and well received by the researchers. [10][11][12] However, electrospun fibers usually have certain defects because of the performance of the material used in electrospinning.

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