High-efficiency Air Filters Research Articles

An electrostatically spun cellulose-based self-powered mask with high efficiency air filtration and ammonia sensing

On construction sites impacted by particulate matter and hazardous gases, portable integrated air filtration equipment with high efficiency, minimal pressure drops and ammonia (NH3) alarms is critical. Triboelectric nanogenerators (TENG) present a sustainable solution by generating self-powered electricity to fulfill these requirements. In this study, we synthesized zeolitic imidazolate framework-8 (ZIF-8) in situ on the surface of titanium carbide (Ti3C2Tx) to create Ti3C2Tx/ZIF-8, grafted it onto cellulose diacetate via tetraethyl orthosilicate, and ultimately developed a cellulose-based nanofibrous membrane through electrospinning, combining it with a negative triboelectric material to construct a self-powered TENG-based mask. The device achieved a balance between a low pressure drop (61 Pa) and high filtration efficiency (99.21 %, 99.71 %, and 99.98 % for PM0.3, PM0.5, and PM1, respectively). Furthermore, the device responds swiftly to NH3; at a concentration of 100 ppm NH3, it achieves a rapid response rate of 83 %, with a response/recovery time as low as 12/14 s. Notably, the device retains its rapid sterilization capability within a short duration (20 min) and demonstrates remarkable stability across its various performance metrics, even after multiple washes. This study presents a novel approach to the development of multi-use, self-powered wearable devices featuring excellent air filtration performance and NH3 detection capabilities.

Enhanced air filtration and ammonia sensing with cellulose nanofibers-based triboelectric nanogenerators under harsh environments

Fire accidents often occur in environments characterized by severe air pollution, toxic gas emissions, and microbial growth, creating significant challenges for developing multifunctional portable healthcare devices. These devices must achieve high filtration efficiency, minimal pressure drop, and the capability to provide early warnings of toxic gas leaks. Triboelectric nanogenerators present a sustainable solution as self-powered energy converters for advanced healthcare applications. In this study, we grafted Ti3C2Tx/MoS2 nanohybrid materials, which form Schottky heterojunctions, onto cellulose diacetate using tetraethyl orthosilicate, followed by electrospinning to produce nanofibrous films. When paired with a negatively charged material, the resulting device achieved an optimal balance with a low-pressure drop (52 Pa) and high filtration efficiency (98.72 % for PM0.3). It also demonstrated exceptional stability under high-temperature and high-humidity conditions. Notably, the device maintained rapid sterilization within 15 min and consistent filtration performance even after multiple washes. Furthermore, the device exhibited precise detection of trace amounts of NH3 (0.1 ppm) and demonstrated a rapid response, achieving an 86 % response rate within 2 s for 100 ppm NH3, providing an early warning 28 s faster than commercial NH₃ monitors. This study introduces a novel approach to the development of multifunctional, self-powered, wearable medical devices that offer high-efficiency air filtration and sterilization, breath monitoring, and rapid toxic gas leakage detection in harsh environments.

Fluorine-Free Amphiphobic SBS/PAN Micro/Nanofiber Membrane by Integrating Click Reaction with Electrospinning for Efficient and Recyclable Air Filtration.

The membrane fouling derived from the accumulated dust pollutants and highly viscous oily particles causes irreversible damage to the filtration performance of air filters and results in a significant reduction in their service life. However, it is still challenging to construct high-efficiency and antifouling air filtration membranes with recyclable regeneration. Herein, the fluorine-free amphiphobic micro/nanofiber composite membrane was controllably constructed by integrating click chemistry reaction and electrospinning technique. Low-surface-energy fibers were constructed by a thiol-ene click chemical reaction between mercaptosilane and vinyl groups of polystyrene-butadiene-styrene (SBS), combined with hydroxyl-terminated poly(dimethylsiloxane) during the electrospinning process. The functional air filter is then prepared by the two-layer composite strategy. Because of the advantages of liquid-like fibrous surface and micro/nanofibrous porous structure, SBS/PAN composite membrane simultaneously shows superior antifouling performances of pollutants and filtration efficiency of over 97% PM0.3 removal. More importantly, the antifouling fibrous membrane still presents a stable and efficient filtration efficiency after multiple washes. Its service life in dust filtration environments is approximately 1.7 times longer than that of the substrate membrane. This work may provide a significant reference for the design of antifouling fiber membranes and high-efficiency air filters with long life spans and reusability.

Construction of Vine-Inspired Antimicrobial Filter with Multiscale 3D Nanonetwork for High-Efficiency Air Filtration.

Enhancing the antimicrobial activity of high-efficiency particulate air (HEPA) filters while maintaining filtration efficiency and pressure drop is currently an urgent issue for preventing the spread of pathogenic microorganisms. Herein, inspired by vines which can enwind fences to fix as well as decorate them, a flexible antimicrobial chitin nanofiber (ChNF@CuOx) was fabricated and loaded onto the rigid glass fiber (GF) skeleton of a HEPA filter. Through the physical interaction, ChNF@CuOx was spontaneously enwound on GF, and ChNF@CuOx itself interweaved to form a new nanonetwork between the GF skeleton. The obtained antimicrobial air filter (ChNF@CuOx/GF) with a unique nanonetwork increased the filtration efficiency of the HEPA filter. Meanwhile, it possessed excellent inactivation ability against Staphylococcus aureus, Escherichia coli, and Candida albicans due to the urchin-like in situ grown CuOx on the ChNF. In particular, the oxygen vacancies generated unexpectedly in CuOx enabled it to produce reactive oxygen species. After eight cycles of antimicrobial assays, the antimicrobial rates of bacteria were higher than 99.5%, and those of fungi were greater than 98.3%. The successful synthesis of antimicrobial fibers and the construction of multidimensional nanoscale structures through a simple postprocessing method provide a new design mentality for antimicrobial functionalization for HEPA filters.

Deep trapped bipolar heterocharges enable electret nanofibrous membranes for high-efficiency PM0.3 filtration

Recently frequent global pandemic outbreak triggers the demand of high-efficiency aerosol filtration materials. Most of traditional electret air filters can hardly achieve high efficiency (>99.99 %) due to limited charge density and inappropriate charge distribution. The influence mechanism of nanofibers bipolar heterocharge configuration on electrostatic capture of airborne particles is still confusing. Herein, a novel strategy to create high-efficiency air filters based on electret nanofibrous membranes with deep trapped heterocharge is reported. Space charges and dipole charges with opposite polarity are formed in electrospun membranes composed of different polymers under in-situ charge injection and electric poling during electrospinning. Nanoscale spatial surface potential mapping on individual nanofiber characterized by Kelvin probe force microscopy demonstrates bipolar heterocharge distribution. Numerical simulation shows that fiber heterocharge distribution endows the electret membrane with greater electrostatic field intensity gradient, resulting in stronger electrostatic force between nanofibers and airborne particles. With bipolar heterocharge configuration and bimodal fiber diameter distribution, the nanofibrous membranes exhibit high-efficiency low-resistance filtration property against 0.3 μm NaCl particles (99.994 %, 97.4 Pa) at 5.3 cm s−1. Furthermore, benefiting from charges with deep trap energy of 1.12 eV, the membranes still maintain 99.972 % filtration efficiency after 40 h exposure in 95 % relatively humidity. The prepared membranes brings new insight in the design of high-efficiency and long-term stability air filtration materials for public health precaution. This study not only reveals influence mechanism of nanofibers heterocharge distribution on electrostatic attraction, but also provides useful guidance for fiber charge configuration design to improve aerosol filtration performance of electret filters.

Development of Particle Filters for Portable Air Purifiers by Combining Melt-Blown and Polytetrafluoroethylene to Improve Durability and Performance

Improving indoor air quality through the use of air purifiers has become a major focus, with emphasis on developing filters with high efficiency, high holding capacity, and low-pressure drop to improve the clean air delivery rate (CADR) for air purifiers. However, although most studies focused on developing media and evaluating their performance, few studies have reached the employment for a pleated filter. In this study, we newly synthesized flat media and pleated filters by combining polytetrafluoroethylene membrane (PT) and melt-blown (MB) materials (PM) and compared its initial performance to that of other air purifier filters (MB, glass fiber, and PT). Additionally, we analyzed how the performance changed after the particles were loaded. The initial efficiency of the PM filter showed a higher quality factor (QF) than the other filters. Furthermore, when more particles were loaded, the penetration of the PM did not change. These results demonstrate the potential of the PM. However, the CADR and submicron-sized (0.02–0.113 μm) CADR (sCADR) were highest for the MB filter due to the initial pressure drop. Therefore, additional improvements are required to apply the PM in air purifiers. However, the results suggest that the PM can be a new alternative for air purifier filters used in medical centers or facilities with vulnerable populations where a high-efficiency particle air (HEPA) filter must be used.

Combustion Properties of Glove-Box Panel Resins Under Fire Accidents

Contributing to the confinement safety evaluation of glove boxes (GBs) connected to high-efficiency particle air filters for radioactive materials under fire accidents, combustion tests of a flammable polymer, i.e., polymethyl methacrylate (PMMA), and a flame retardant polymer, i.e., polycarbonate (PC), as typical GB panel resins have been conducted with an engineering-scale combustion apparatus. Combustion properties such as the mass loss rate (MLR) and the heat release rate (HRR) of PMMA and PC were investigated in the combustion tests. From our results, the relationships of MLR and HRR to the surface area of the plate type of PMMA and PC were deduced.

Preparation of modified halloysite nanotubes@Ag3PO4/polyacrylonitrile electrospinning membranes for highly efficient air filtration and disinfection

Particulate matters (PMs) and airborne bacteria are among the most severe indoor air issues due to their substantial implications for human health. Therefore, it was imperative to conduct a comprehensive investigation on air filtration materials with superior filtration performance and antibacterial properties. Here, the m-Hal@Ag3PO4 composite particles were prepared by using modified halloysite nanotubes (m-Hal) as the support of Ag3PO4 nano-photocatalysts. These composite antibacterial particles were uniformly dispersed within a polyacrylonitrile (PAN) solution and were subsequently electrospun into m-Hal@Ag3PO4/PAN composite nanofiber membranes (CNMs) possessing excellent antibacterial properties. The incorporation of 30 wt% m-Hal@Ag3PO4 additionally enhanced the filtration efficiency of PM0.3 to 99.9%, at an airflow rate of 32 L/min, while concurrently reducing the pressure drop by 36.7%. The photocatalytic degradation efficiency of CNMs towards ciprofloxacin reached 99%. The antibacterial experiments demonstrated that CNMs exhibited potent antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli)under dark and light conditions. Under visible light irradiation, the average diameter of the inhibition zone for the composite membrane surpassed that observed under dark conditions, indicating a predominant enhancement in its antibacterial efficacy through photocatalysis. The enhanced photocatalytic performance and excellent stability can be attributed to the incorporation of Ag3PO4 with m-Hal, which enhanced the dispersibility and facilitated efficient carrier separation of Ag3PO4. The present type of CNMs exhibited the advantages of high efficiency and low resistance air filtration, photodegradation ability, and recyclability, thereby enhancing the efficacy and lifespan of PMs filtration, bacteria disinfection, and antibiotic degradation. This offered a novel concept and viable approach for indoor air and water purification based on electrospinning technology.

In-situ polarized coaxial PVDF/PL nanofiber filtration membrane with high efficiency, low resistance and antimicrobial properties

Aerosols are prone to breed bacteria on air filtration materials so as to cause secondary air pollution, especially carrying bacteria and viruses. This paper utilized coaxial electrospinning technology with traditional Chinese medicine Physalis alkekengi Linn as the core layer antibacterial material and polyvinylidene fluoride/polyacrylonitrile mixed solution as the shell layer material. Nonsolvent phase separation technology was employed to prepare the porous shell layer, achieving sustained slow-release and long-lasting antibacterial effects from the core P. alkekengi Linn. In addition, an in-situ polarization technology from high voltage in electrospinning process was adopted to achieve permanent polarization of polyvinylidene fluoride, which changed from α-crystal to β-crystal. Using the electrostatic charge adsorption effect and the ultra-fine pore size screening of the nanofiber membrane, high-efficiency and low-resistance filtration of aerosols above 0.3 μm was achieved (99.98% filtration efficiency and filtration resistance less than 25 Pa). It can be widely used in the field of air filtration and protection in high-risk environments such as stations, schools, and hospitals, achieving long-lasting antibacterial, high-efficiency, and low-resistance air filtration and protection.

Trap-induced hydro-charging polylactic acid nonwovens with high charge storage capability for stable and efficient air filtration

Under the background of carbon neutrality, eco-friendly biodegradable polylactic acid (PLA) melt-blown nonwovens have been developed in air filtration. Nevertheless, the filtration performance of existing PLA melt-blown nonwovens is in an embarrassing situation and fails to meet the requirement of high efficiency air filters. Here, with controllable doping of N, N′-ethylene bis-stearamide (EBS), and barium titanate (BaTiO3) into PLA, through the melt-blown process, the charge-storage capacity of PLA nonwovens enhanced significantly. By utilizing the hydro-charging technology thereafter, we have prepared hydro-charged PLA/EBS/BaTiO3 nonwovens (HCP-EB) with excellent filtration performances. The doped EBS and BaTiO3 could improve the crystallization and charge storage capacity of PLA during the melt-blown process, thus constructing a large number of interfacial traps between crystalline and amorphous regions, leading to more electric charges captured during the hydro-charging process. The HCP-EB exhibited a high filtration efficiency (99.69 %) for PM0.3, a low pressure drop (27.44 Pa), and superior charge storage stability. Furthermore, the HCP-EB, remained at 99.18 % filtration efficiency after 48 h of treatment at 90 % relative humidity. After 3 months of storage, it still possessed an excellent filtration efficiency (99.02 %). Our work will contribute to the practical application of PLA melt-blown nonwovens in air filters and masks, and inspire the research of next-generation biodegradable electret air filtration materials.

Multi-functional nanofibrous membrane with antibacterial property for highly effective capture of PM0.3 and hydrogen sulfide

In order to reduce the possible harm caused by air pollution, including particulate matters (PM), harmful gases and airborne pathogens, high-efficiency air filtration materials are attracting more and more attention. Therefore, multifunctional materials that can filter these pollutants and kill pathogenic bacteria simultaneously are urgently desired. Herein, a copper-coordinated nanofibrous membrane, named PAN-P-Cu, was successfully prepared based on polyacrylonitrile (PAN) nanofibers grafted polyethyleneimine (PEI) by electrospinning and coordination assembly method. The PAN-P-Cu showed high filtration efficiency (99.9%) towards PM0.3 under an airflow velocity of 5.3 cm s−1 and high filtration efficiency (99.94%) towards PM10, respectively. Importantly, used membrane could be regenerated by a simple washing process. Moreover, PAN-P-Cu possessed removal property of 60 mg g−1 for hydrogen sulfide through the occurrence of chemical reactions. Furthermore, the PAN-P-Cu also exhibited excellent antibacterial activities against Escherichia coli and Staphylococcus aureus (>99.99%). This work may provide new insights on designing high-performance and multi-functional air filtration materials for public health protection in complicated environments.

Virus removal by high-efficiency air (HEPA) filters and filtration capacity enhancement by nanotextiles: a pilot study.

Portable household air purifiers are widely used devices designed to maintain a high-quality level of indoor air. Portable air purifiers equipped with the high-efficiency air (HEPA) filter served 100h in a household space occupied by two adults without any symptoms of respiratory tract infection. The main objective of the study was to determine microbial contamination on the HEPA filter and to investigate if the selected nanotextile monolayer made of polyamide 6 (PA6) nanofibers can capture potential microorganisms when installed downstream of the HEPA filter as the final filtration medium. Samples were taken from the inlet and outlet surfaces. Samples from the nanotextile were collected in the same manner as from the HEPA filter. QIAStat DX® 1.0 Analyzer using the Respiratory SARS CoV-2 Panel multiplex PCR detection system was selected for microorganism detection. Adenovirus was detected on the inlet surface of the HEPA filter. The outlet surface of the filter contained no viruses included in the Respiratory SARS CoV-2 Panel portfolio. The nanotextile monolayer was replaced twice during the 100h of operation, so three pieces were used and all contained coronavirus 229 E. Coronavirus 229 E was then detected in the nasopharynx of one of the members of the household as well. It may be assumed that the selected nanotextile is capable of capturing a virus of a small size.

Development of biodegradable nanofiber filters based on surface-modified cellulose nanofibers with graphene oxide for high removal of airborne particulate matter

Airborne particulate matter is a pressing environmental and public health concern globally. This study aimed to develop sustainable filtration materials from cellulose nanofibers (CNFs) modified with graphene oxide (GO) to capture fine particulates from air effectively. CNFs were extracted from α-cellulose via mechanical grinding and modified with 0.5–1.5 wt% GO solution by ultrasonication to produce CNF-GO nanocomposites. These were freeze-dried into highly porous, lightweight aerogels for air filtration applications. Fourier transform infrared spectroscopy (FT-IR) confirmed GO incorporation through hydroxyl group interactions. Field emission scanning electron microscopy (FE-SEM) revealed a porous 3D network with reduced porosity after GO addition due to pore blocking. X-ray diffraction analysis showed the cellulose I crystal structure was retained after modification. Brunauer-Emmett-Teller (BET) measurements indicated increased density but decreased surface area and pore volume with GO loading. The thermogravimetric analysis demonstrated improved thermal stability with GO incorporation due to oxidative reactions and a barrier effect. The particulate absorption efficiency markedly increased from 86.37 % to 99.98 % for CNFs modified with 1.5 wt% GO due to the high surface area, surface oxygen functionalities, and nanoplatelet morphology of GO. The nanofiber filters with 1.5 wt% GO exhibited a maximum absorption efficiency of 99.98 % and a quality factor of 0.0912 Pa−1. Although GO reduced biodegradability, substantial degradation occurred under soil conditions. Overall, the sustainable, high-efficiency CNF-GO air filters developed in this work demonstrate immense promise for controlling air pollution and protecting human health.

One-step fabrication of polylactic acid (PLA) nanofibrous membranes with spider-web-like structure for high-efficiency PM0.3 capture

High-efficiency air filters are in high demand to protect human health from the threat of ultrafine particulate matters (PM). However, most commercial air filters are less effective for PM0.3 capture and/or still suffer from undesirable pressure drops. They are also typically petroleum-based. Herein, a double-jet synchronous electrospinning technology was demonstrated to fabricate spider-web-like polylactic acid (PLA) nanofibrous membranes (SPNM) in one step. The properties of spinning solutions were regulated to construct favorable multi-scale nanofiber and bead structures that mimicked the structural units in spider-webs. The as-prepared SPNM exhibited excellent filtration efficiency (99.87 %) and high quality factor (0.321 Pa−1) against the PM0.3, while presenting an attractively low pressure drop (19 Pa). Additionally, the filtration performance of SPNM was almost completely preserved during 10-cycle tests and the 6-month long-term tests, showing excellent function stability and durability. Benefiting from its good hydrophobicity (WCA = 143.2°), SPNM also presented a satisfactory filtration efficiency (>99.37 %) with low pressure drop (18 Pa) at an environment with humidity at 90 % against PM0.3. Furthermore, the unique structure increased the mechanical strength of SPNM, facilitating the processability for practical applications. Overall, this work may shed light on a promising approach for developing biomass-based, highly efficient filtration materials with hierarchical structures.

Using modified raw materials to fabricate electrospun, superhydrophobic poly(lactic acid) multiscale nanofibrous membranes for air-filtration applications

Nanofiber filtration materials are of considerable interest owing to their excellent interception capability for particulate matter (PM). However, numerous obstacles, such as highly complex manufacturing techniques, a short service life, low efficiency, and poor uniformity, hinder the large-scale production and utilization of these materials. In this work, multiscale modified poly(lactic acid) nanofibrous membranes (diameters: ∼49.9 and ∼223.22 nm) were fabricated by attaching long-chain alkyl groups with low surface energy to raw materials via chemical grafting and subsequently using the modified poly(lactic acid) for needleless electrospinning. This modification method facilitates the stable preparation process required for large-scale production. The membranes have small pores (∼340 nm in diameter) with a narrow pore-size distribution, superhydrophobicity (water contact angle: 155°), relatively high tensile strength (20.36 MPa), high filtration efficiency (>98.500% for PM0.3), and low resistance (<0.032% of atmospheric pressure), and they can maintain a filtration efficiency above 90.000% after 50 blowback cycles. Moreover, for particles with a diameter of <0.3 μm, the composites exhibit an initial filtration efficiency of 99.995%, which only decreases to 98.000% after 10 washing cycles. Therefore, this work presents a promising solution for the large-scale production of high-efficiency air filters.

In situ one-step production of hierarchical silicon nanofilaments/polyimide nonwovens for environmentally sustainable applications

Highly architectures with roughness and low surface energy reagent are the key toward developing superwetting materials. Silicon nanofilaments (SiNFs) had been grown on polyimide (PI) nonwovens by liquid deposition, which could enhance the hydrophobicity of the nonwovens without additives. These newly prepared nonwovens with micro/nano-scale secondary rough structures demonstrate outstanding air filtration and oil/water separation abilities. The in situ hybrid nonwoven shows extremely high efficiency air filtration function (the increase in filtration efficiency for PM1.0 by 63 % with stable pressure drop), stable particulate filtering effect after storage 15 months at ambient temperature, and good thermal stability at 350 °C. The oil/water separation test showed a separation efficiency of over 98 % and a high flux (above 40,000 Lm-2h−1) for different oil/water mixtures. Additionally, nonwovens prepared in this study demonstrated exceptional durability and stability when subjected to corrosive conditions, as evidenced by the results of realistic industrial simulations. The introduction of SiNFs on nonwoven, which combines the multiple capture and wettability properties, shows promise as a potential solution for large-scale air filtration and oil/water separation.

Upcycling of Waste Fabrics into High-Efficiency Air Filters Using Flexible Polyimide Aerogel Coatings

Upcycling of Waste Fabrics into High-Efficiency Air Filters Using Flexible Polyimide Aerogel Coatings

Effective preparation of environmentally friendly polyglycolic acid (PGA) nanofibrous membrane with antibacterial property for high-efficiency and low-resistance air filtration

In recent years, the antibacterial air filters have been crucial for protecting human health. However, most commercial filters are made of non-biodegradable petroleum polymers, which poses a great challenge for environment protection of recycling after large-scale use. Hence, the air filtration membrane, biodegradable polyglycolic acid loaded with antibacterial ε-polylysine-dialdehyde microcrystalline celluloses (PGA@EPL-DAMCs), was prepared by electrospinning. The incorporation of EPL-DAMCs varied the morphology of the resultant PGA@EPL-DAMCs and endowed them with good antibacterial activity. In addition, it was found that the PGA/EPL-DAMC-24% exhibited the best filtration efficiency (99.83%) and bacterial rate (up to 99.97% and 99.99% for E.coli and S.aureus, respectively). Finally, the degradation performance of the PGA electrospun membrane was also investigated, indicating that PGA@EPL-DAMCs composite nanofiber membranes had broad prospects in biodegradable filtration material, can be applied to develop biodegradable and environmentally friendly medical protective materials with highly efficient air filtration and significant antimicrobial effects.

High-efficiency air filter aerogel resembling blood cell with heterogeneous epitaxial growth of zeolitic imidazolate framework-8 anchored on tunicate cellulose nanofibers for integrated air cleaning

Metal-organic frameworks (MOFs) possess highly ordered porous structures and photocatalytic capabilities, making them ideal for air cleaning and antibacterial applications. However, the crystallization kinetics of MOFs constrain their crystal structure, which limits their practical usage for air cleaning and other applications. Herein, we present a non-MOF template strategy to achieve heterogeneous epitaxial growth of zeolitic imidazolate framework-8 (ZIF-8) on cellulose extracted from tunicate. TEMPO-oxidation tunicate cellulose nanofibers (TOCNFs) have a high length-diameter ratio (>1000) and negatively charged carboxyl and hydroxyl groups that serve as suitable templates to promote heterogeneous nucleation of the ZIF-8 crystal, thereby resulting in the fabrication of a unique porous structure resembling blood cell. The ZIF-8@TOCNFs aerogel shows good porosity performance, achieving a maximum particulate matter (PM) removal efficiency of 95.80 % with a low pressure drop of 14 Pa at an air-flow velocity of 0.34 m/s. Compared to other works and commercial filters, ZIF-8@TOCNFs aerogel exhibits a higher quality factor (QF) of up to 0.197 Pa−1. Furthermore, ZIF-8@TOCNFs aerogel also demonstrates remarkable antibacterial and antiviral performance without UV photocatalysis. This unique design of ZIF-8@TOCNFs aerogel opens a new avenue for non-MOF template growth of MOF-on-MOF heterostructures and provides a novel strategy for preparing high-performance air filters with an integrated performance of low pressure drop, high removal efficiency and QF, great antibacterial and antiviral properties.

Preparation of antibacterial composite fiber membrane for air filtration with micro/nano structure

With the aggravation of environmental pollution and the worldwide epidemic of infectious diseases, there is a higher demand for air filtration materials to intercept fine particulate matter and capture biological pollutants. Polypropylene (PP)/polycarbonate (PC) blends were melt blown and electrospun with polytetrafluoroethylene (PTFE) on their surfaces. The PP/PC/PTFE membranes structure with micro-nanostructure was constructed through the melt-blown layer with micron structure and the electrospun layer with the nanostructure. Carboxymethyl chitosan (CMCS) was loaded onto the surface of the PP/PC melt-blown layer. The synergistic effect of micro-nanostructure and CMCS can effectively capture PM2.5 and make the composite membrane have excellent antibacterial performance. The inhibition rates of PP/PC/PTFE composite membrane loaded with 5% CMCS against Staphylococcus aureus and Escherichia coli reached 81.54% and 86.1%, respectively. The filtration efficiency of PP/PC/PTFE composite membrane loaded with 5% CMCS is close to 100% for 0.25 μm particles, and the average filtration efficiency for 0.200–4.596 μm and 0.200–2.500 μm particles is 97.31% and 97.27%, respectively. After washing and drying five times, the corresponding inhibition rate only lost 16.52% and 4.24%. The micro/nano structure composite membrane prepared in this study has good antibacterial performance, high filtration efficiency, good stability, and is an excellent antibacterial high efficiency air filter. It provides a new idea for the preparation of air filter fiber composites.