Electroactive, Antibacterial, and Biodegradable Poly(lactic acid) Nanofibrous Air Filters for Healthcare

Biodegradable air filter with electrospun composite nanofibers and cellulose fibers dual network: Enhanced electrostatic adsorption, humidity resistance, and extended service life

Cellulose-based materials have great potential as degradable air filters. Regretfully, the application is limited by their low electrostatic adsorption and hydrophilicity. To meet with the challenge, we designed a composite air filter with dual network. Composite cellulose acetate nanofibers were electrospun on a cellulose-fibers paper substrate, and the resulted multi-scale spider-web-like structure showed high filtration efficiency as well as low resistance. Electrets (silicon nitride and tourmaline) were composited to enhance the electrostatic adsorption for PMs. Hydrophobic modification improved the ability to retain electrostatic charge, promoting the filtration under humid environment. The filtration efficiency for PM0.3 exceeded 99 %, while the pressure drop was only 45.7 Pa. The filtration performance could be maintained for over 12 hours under 90 % relative humidity, and the filter could be completely degraded in natural environment within 80 days.

Lotus leaf-inspired poly(lactic acid) nanofibrous membranes with enhanced humidity resistance for superefficient PM filtration and high-sensitivity passive monitoring

The biomimetic design principles offer promising solutions to fabrication of multifunctional nanofibrous membranes (NFMs) with on-demand hierarchies and properties. Herein, a combined electrospinningelectrospray approach was employed to firmly anchor MOF nanocrystals onto poly(lactic acid) (PLA) nanofibers, resembling the naturally occurring dense protrusions at the lotus leaf. The formation of unique MOF-protruding superstructures gave rise to an exceptional combination of increased electroactivity, in-situ electret properties and charge regeneration mechanisms, as well as remarkable humidity resistance. With 8 wt% bioinspired MOF-protrusions for the electrospunelectrosprayed PLA NFMs (BM-PLA8), the initial surface potential was elevated to 3.0 kV and slightly decreased to 2.6 kV after 7-day ageing, in clear contrast to only 1.1 and 0.6 kV for the normal PLA, respectively. Moreover, the tribo-output voltage and current were significantly promoted for BM-PLA8 (64.5 V and 151.6 nA), demonstrating high humidity resistance and long-term robustness even at 90 % RH. It conferred distinct improvements in air filtration performance for BM-PLA8 even at the highest airflow velocity of 85 L/min (below 250 Pa, 99.9 % and 95.0 % removal of PM2.5 and PM0.3, respectively), far surpassing the normal PLA counterpart (nearly 350 Pa, 89.5 % and 75.8 %). Arising from the respiration-driven charge regeneration mechanisms, passive respiratory monitoring of high sensitivity was demonstrated for BM-PLA8, showing great promise for efficient healthcare under the challenging circumstances.

Self-crystal electret poly(lactic acid) nanofibers for high-flow air purification and AI-assisted respiratory diagnosis

Particulate matters (PMs), one of the major airborne pollutants, continue to seriously threaten human health and the environment. Here, a self-crystal-induced electret enhancement (SCIEE) strategy was developed to promote the in-situ electret effect and polarization properties of electrospun poly(L-lactic acid) (PLLA) nanofibers. The strategy specifically involved the elaborate pre-structuring of stereocomplex crystals (SCs) with uniform dimensions (∼300 nm), which were introduced into PLLA electrospinning solution as the electrets and physical cross-linking points of high density. It enabled direct fabrication of self-crystal electret poly(lactic acid) (SCE-PLA) nanofibrous membranes (NFMs), effective regulation of nanofiber morphology, enhanced generation of electroactive phases (β phases, SCs, and interfacial domains), synergistically contributing to remarkable increase of dielectric constant (2.48), surface potential (4.60 kV) and charge regeneration performance (tribo-output voltage as high as 37.60 V). This permitted multiple improvements in physical interception and electrostatic adsorption of PMs, as exemplified by efficient removal of PM0.3 and PM2.5 (94.91 % and 99.15 %) with ultralow air resistance (57.2 Pa, 32 L/min), in clear contrast to the pure PLA counterpart (82.66 % and 80.98 %). Given sustainable regeneration of plentiful charges, SCE-PLA NFMs exhibited long-term electret effect and PM0.3 removal (92.53 %) even at intensive inhalation and exhalation airflow (120 and 100 L/min). Moreover, the electroactive SCE-PLA NFMs were ready to realize high-accuracy monitoring (99.23 %) of the respiratory patterns. Our SCIEE strategy opens up a promising pathway to fabricate ecofriendly nanofibers featuring superior in-situ electret effect and charge regeneration capability, appealing for air purification and passive monitoring.

High-efficiency respiratory protection and intelligent monitoring by nanopatterning of electroactive poly(lactic acid) nanofibers

The advent of multifunctional nanofibrous membranes (NFMs) has led to the development of next-generation air filters that are ready to intercept fine particulate matters (PMs) and monitor the respiratory diseases. However, it is still challenging to fabricate biodegradable NFMs featuring the desirable combination of high filtration efficiencies, low air resistance, and intelligent real-time monitoring. Herein, a hierarchical nanopatterning approach was proposed to functionalize the stereocomplexed poly(lactic acid) (PLA) (SC-PLA) nanofibers via the combined electrospinning of SC-PLA and electrospray of CNT@ZIF-8 nanohybrids. The nanopatterned SC-PLA (NSC-PLA) NFMs were characterized by largely increased surface activity and electroactivity, as evidenced by the nearly two-fold increase in surface potential (up to 7.3 kV) and substantial improvements in the dielectric properties. Furthermore, the NSC-PLA NFMs exhibited excellent tribo-output performance, yielding a voltage of as high as 13.5 V for NSC-PLA NFMs loaded 10 % nanohybrids (NSC-PLA10). In particular, the exceptionally high electroactivity and unique protrusion structure together contributed to promote the filtration efficiencies, while providing a low pressure drop (e.g., 96.1 % for PM2.5 and 88.3 % for PM0.3, only 67.6 Pa of NSC-PLA10, at 32 L/min). More importantly, NSC-PLA NFMs enabled real-time monitoring of physiological signals during different respiratory states, as evidenced by the output voltages of 17.2, 32.9 and 37.5 mV for normal breath, fast breath and cough recorded by NSC-PLA10. The proposed NSC-PLA NFMs show enormous potential in the fields of air filtration and real-time respiratory monitoring, thus providing ecofriendly solutions to personal health management.

Implantation of web-like cellulose nanofibrils on electrospun fibrous membrane for boosting filtration performance

Air pollution such as particulate matter is always a serious threat to public health, thus many disposable and degradable air filters were designed to deal with this severe challenge avoiding the secondary pollution after discarding. Herein, inspired by the natural spider web structure, a hierarchical porous composite fibrous membrane containing web-like cellulose nanofibrils (CNF) was developed. The implanted porous CNF membranes with web-like among the inter-fiber voids of electrospun poly(ethylene-co-viny alcohol) fibrous membrane were realized via a layer-by-layer (LBL) method followed by an elevated-temperature drying, which exhibit a smaller diameter with one or two orders of magnitude reduction comparing with the substrate fibers. The morphology of implanted CNF membranes can be regulated by changing the CNF dispersion concentration, PH, solution composition as well as the LBL times. The addition of a small amount of isopropyl alcohol to the CNF solution can efficiently facilitate the implantation of web-like CNF on substrate, resulting in both improvements on the mechanical properties and filtration capacity. The result shows that the implanted web-like CNF of as-prepared composite membrane can enhance the PM 0.3 capture ability (reaching 96.8 %) while not surge its pressure drop (225.7 Pa) exceeding N95 standard. This work presents a new design and fabrication of CNF-based filter materials directly without using freeze drying, which can not only provide a fully or partially biodegradable air filter but also give encouragement to explore new filters efficiently.

Ultralow-resistance and self-sterilization biodegradable nanofibrous membranes for efficient PM0.3 removal and machine learning-assisted health management

The development of multifunctional nanofibrous membranes (NFMs) that enable anti-viral protection during air purification and respiratory disease diagnosis for health management is of increasing importance. Herein, we unraveled a heterostructure-enhanced electro-induced stereocomplexation (HEIS) strategy to fabrication of poly(lactic acid) (PLA) NFMs enabling a combination of efficient PM removal, respiratory monitoring and self-sterilization. The strategy involved an electro-induced stereocomplexation (EIS) approach to trigger the generation of hydrogen bonds between enantiomeric poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) chains, promoting CO dipole alignment and molecular polarization during electrospinning. This was further enhanced by incorporation of Ag-doped TiO2 (Ag-TIO) nanodielectrics to promote the electroactivity and surface activity, conferring profound refinement of PLA nanofibers (from 460 nm to an ultralow level of 168 nm) and high porosities of over 91 %. Arising from the sustainable generation of plentiful charges based on triboelectric nanogenerator (TENG) mechanisms, the electroactive PLA NFMs exhibited remarkable triboelectric properties even in high-humidity environments (80 %RH), excellent PM0.3 filtration efficiency with an ultralow pressure drop (93.1 %, 31.8 Pa, 32 L/min), and 100 % antimicrobial efficiency against both E. coli and S. aureus. Moreover, a deep-learning algorithm based on convolutional neural network (CNN) was proposed to recognize various respiratory patterns. The proposed strategy confers the biodegradable NFMs an unusual combination of ultralow-resistance air purification and machine learning-assisted health management, signifying promising prospects in environmental protection and personal healthcare.

Highly air-permeable and dust-holding protective membranes by hierarchical structuring of electroactive poly(lactic acid) micro- and nanofibers

The application of biodegradable electrospun poly(lactic acid) (PLA) fibrous membranes (FMs) toward respiratory protection has long been dwarfed by the poor electret effect and short service life. Herein, a micro-on-nano (MON) approach was proposed to fabricate highly electroactive dual-scale poly(lactic acid) (DS-PLA) FMs consisting of inner-layer nanofibers (667 nm) and outer-layer microfibers (1.22 µm). Customized Ag-decorated BTO (Ag-BTO) dielectrics were incorporated to improve the electret effect and charge storage stability of DS-PLA FMs, contributing to the improved dielectric constants (1.40), surface potential (11.4 kV), and triboelectric performance (output voltage of 34.2 V at 10 N, 0.5 Hz). The unique hierarchies and profound electrostatic adsorption effect synergistically allowed the DS-PLA FMs to achieve high PM filtration efficiencies (99.10 % for PM2.5, 90.37 % for PM0.3, 32 L/min) at a reduced pressure drop (only 58.8 Pa). Furthermore, benefiting from the cascade filtration mechanisms, the DS-PLA FMs demonstrated superior dust holding capacity (9.4 g/m2), which was 3.2 times higher than that of normal PLA. With the assistance of convolutional neural network (CNN), a set of breathing patterns could be recognized with a classification accuracy as high as 96.7 %. This work provides a facile pathway to significantly prolong the service life of electrospun PLA filters for high-performance air filtration and deep learning-assisted respiratory monitoring.

Biodegradable Poly (L-Lactic acid) Fibrous Membrane with Ribbon-Structured Fibers and Ultrafine Nanofibers Enhances Air Filtration Performance

Here, the poly (l-lactic acid) (PLLA) membrane with multi-structured networks (MSN) is successfully prepared by electrospinning technology for the first time. It is composed of micron-sized ribbon-structured fibers and ultrafine nanofibers with a diameter of tens of nanometers, and they are connected to form the new network structure. Thanks to the special fiber morphology and structure, the interception and electrostatic adsorption ability for against atmospheric particulate matter (PM) are significantly enhanced, and the resistance to airflow is reduced due to the "slip effect" caused by ultrafine nanofibers. The PLLA MSN membrane shows excellent filtration performance with ultra-high filtration efficiency (>99.9% for PM2.5 and >99.5% for PM0.3) and ultra-low pressure drop (≈20 Pa). It has demonstrated filtration performance that even exceeds current non-biodegradable polymer materials, laying the foundation for future applications of biodegradable PLLA in the field of air filtration. In addition, this new structure also provides a new idea for optimizing the performance of other polymer materials.

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.

Hierarchically Nano-Decorated Poly(lactic acid) Nanofibers for Humidity-Resistant Respiratory Healthcare and High-Accuracy Disease Diagnosis

The application of biodegradable and eco-friendly poly(lactic acid) (PLA) nanofibrous membranes (NFMs) toward respiratory healthcare has long been thwarted by the poor electroactivity and low surface activity of PLA. Herein, we unravel a microwave-assisted route to fabricate rod-like ZnO nanodielectrics, which were decorated with dopamine (ZnO@PDA) and anchored at the PLA nanofibers via an electrospinning-electrospray approach. The PLA/ZnO@PDA NFMs featured a substantially elevated specific surface area (up to 20.7 m2/g), increased dielectric constant (nearly 1.8) and a surface potential as high as 9.5 kV, resulting in superior air filtering performance (99.45% for PM0.3, 94.1 Pa, 32 L/min) compared with the pure PLA counterpart (90.04%, 169.0 Pa, 32 L/min). The notably increased electroactivity endowed the PLA/ZnO@PDA NFMs with significant improvements in triboelectric properties (output voltage of 11.5 V at 10 N, 0.5 Hz), laying down the cornerstone for self-powered monitoring of personal respiration. More importantly, a deep learning-assisted diagnostic system was developed based on respiration-driven signal patterns, enabling intelligent and real-time disease diagnosis with 100% accuracy for the protective membranes. The proposed hierarchical nanodecoration strategy opens up new possibilities for engendering eco-friendly nanofibers with an exceptional combination of efficient respiratory healthcare and intelligent diagnosis.

Bio-inspired gradient poly(lactic acid) nanofibers for active capturing of PM0.3 and real-time respiratory monitoring

The concept of bio-inspired gradient hierarchies, in which the well-defined MOF nanocrystals serve as active nanodielectrics to create electroactive shell at poly(lactic acid) (PLA) nanofibers, is introduced to promote the surface activity and electroactivity of PLA nanofibrous membranes (NFMs). The strategy enabled significant refinement of PLA nanofibers during coaxial electrospinning (∼40 % decline of fiber diameter), accompanied by remarkable increase of specific surface area (nearly 1.5 m2/g), porosity (approximately 85 %) and dielectric constants for the bio-inspired gradient PLA (BG-PLA) NFMs. It largely boosted initial electret properties and electrostatic adsorption capability of BG-PLA NFMs, as well as charge regeneration by TENG mechanisms even under high-humidity environment. The BG-PLA NFMs thus featured exceptionally high PM0.3 filtration efficiencies with well-controlled air resistance (94.3 %, 163.4 Pa, 85 L/min), in contrast to the relatively low efficiency of only 80.0 % for normal PLA. During the application evaluation of outdoor air purification, excellent long-term filtering performance was demonstrated for the BG-PLA for up to 4 h (nearly 98.0 %, 53 Pa), whereas normal PLA exhibited a gradually declined filtration efficiency and an increased pressure drop. Moreover, the BG-PLA NFMs of increased electroactivity were ready to generate tribo-output currents as driven by respiratory vibrations, which enabled real-time monitoring of electrophysiological signals. This bio-inspired gradient strategy opens up promising pathways to engender biodegradable nanofibers of high surface activity and electroactivity, which has significant implications for intelligent protective membranes.

Hierarchical Porous Reduced Graphene Oxide/Poly(l-lactic acid) Fiber Films: The Influence of Recrystallization on Strength

Electrospinning technology for fabricating nanofiber films and the Hummer method for synthesizing graphene oxide (GO), along with subsequent reduction, have been significantly advanced, demonstrating immense potential for large-scale industrial applications. Nanofibrous films loaded with reduced graphene oxide (rGO) have been widely explored for their applications in electromagnetic shielding, the biomedical fields, and pollutant adsorption. However, fragile mechanical performance of electrospun fibers with limited surface post-treatment methods has somewhat hindered their further industrial development. In response to this challenge, we propose a dual-regulation strategy involving post-treatment to form porous nanofiber films and the controlled flake size of rGO for surface coating during preparation. This approach aims to achieve poly(l-lactic acid) (PLLA)/rGO electrospun fibrous films with enhanced mechanical properties. It offers a roadmap for the continued application and standardized production of fibrous films loaded with rGO.

Fabrication of Poly(Lactic Acid)@TiO2 Electrospun Membrane Decorated with Metal-Organic Frameworks for Efficient Air Filtration and Bacteriostasis

The development of high-performance filtration materials is essential for the effective removal of airborne particles, and metal-organic frameworks (MOFs) anchored to organic polymer matrices are considered to be one of the most promising porous adsorbents for air pollutants. Nowadays, most air filters are generally based on synthetic fiber polymers derived from petroleum residues and have limited functionality, so the use of MOFs in combination with nanofiber air filters has received a lot of attention. Here, a conjugated electrostatic spinning method is demonstrated for the one-step preparation of poly(lactic acid) (PLA) nanofibrous membranes with a bimodal diameter distribution and the anchoring of Zeolitic Imidazolate Framework-8 (ZIF-8) by the introduction of TiO2 and in situ generation to construct favorable multiscale fibers and rough structures. The prepared PLA/TZ maintained a good PM2.5 capture efficiency of 99.97%, a filtration efficiency of 96.43% for PM0.3, and a pressure drop of 96.0 Pa, with the highest quality factor being 0.08449 Pa-1. Additionally, ZIF-8 was uniformly generated on the surface of PLA and TiO2 nanofibers, obtaining a roughened structure and a larger specific surface area. An enhanced filtration retention effect and electrostatic interactions, as well as active free radicals, can be generated for the deep inactivation of bacteria. Compared with the unmodified membrane, PLA/TZ prepared antibacterial characteristics induced by photocatalysis and Zn2+ release, with excellent bactericidal effects against S. aureus and E. coli. Overall, this work may provide a promising approach for the development of efficient biomass-based filtration materials with antimicrobial properties.

Fabrication of antibacterial poly (L-lactic acid)/tea polyphenol blend films via reactive blending using SG copolymer

Poly (L-lactic acid) (PLLA) composite materials with both excellent antibacterial properties and mechanical properties are highly desirable for both food packaging and biomedical applications. However, a facile method to prepare transparent PLLA composite films with both excellent antibacterial and mechanical properties is still lacking. In this work, blend films based on PLLA, tea polyphenols (TP) and poly (styrene-co-glycidyl methacrylate) (SG) copolymers (PLLA/TP/SG) were prepared by melt blending using twin screw extruder. The blend films showed high transparency with a brownish color originated from tea polyphenols. Both SEM and DSC analyses confirmed that the blends are thermodynamically compatible. GPC and mechanical assessments demonstrated that the PLLA/TP binary blends exhibit reduced molecular weight and compromised mechanical properties, compared to neat PLLA. However, incorporating SG copolymer resulted in increased molecular weight and improved mechanical properties for the PLLA/TP/SG blends. The FT-IR spectra exhibited a shift to lower wavenumber for the absorption peak associated with the benzene ring on TPs after blending with PLLA and SG, indicating the occurrence of transesterification between PLLA and TP. Plate coating studies revealed that the PLLA/TP/SG blends with TP incorporation at 5 wt% exhibited a bacteriostatic rate of 99.99 % against Staphylococcus aureus and Escherichia coli. Overall, our study reveals that the PLLA/TP/SG blend films exhibit excellent antibacterial properties coupled with good mechanical properties, rendering them a promising candidate for antibacterial packaging materials.

Nanopatterning of beaded poly(lactic acid) nanofibers for highly electroactive, breathable, UV-shielding and antibacterial protective membranes

Despite great potential in fabrication of biodegradable protective membranes by electrospinning of poly(lactic acid) (PLA) nanofibers, it is still thwarted by smooth surfaces and poor electroactivity that challenge the promotion of electret properties and long-term air filtration performance. Here, a microwave-assisted synthetic method was used to customize dielectric TiO2 nanocrystals of ultrasmall and uniform dimensions (∼30 nm), which were homogeneously embedded at beaded PLA nanofibers (PLA@TiO2, diameter of around 280 nm) by the combined "electrospinning-electrospray" approach. With small amounts of TiO2 (2, 4 and 6 wt%), the nanopatterned PLA@TiO2 nanofibrous membranes (NFMs) were characterized by largely increased dielectric constants (nearly 1.9), surface potential (up to 1.63 kV) and triboelectric properties (output voltage of 12.2 V). Arising from the improved electroactivity and self-charging mechanisms, the nanopatterned PLA@TiO2 NFMs exhibited remarkable PM0.3 filtration properties (97.9 %, 254.6 Pa) even at the highest airflow rate of 85 L/min, surpassing those of pure PLA membranes (86.2 %, 483.7 Pa). This was moreover accompanied by inhibition rates of 100 % against both E. coli and S. aureus, as well as excellent UV-blocking properties (UPF as high as 3.8, TUVA of 50.9 % and TUVB of 20.1 %). The breathable and electroactive nanopatterned PLA NFMs permit promising applications in multifunctional protective membranes toward excellent UV shielding and high-efficiency removal of both PMs and pathogens.

Ethyl cellulose/gelatin/β-cyclodextrin/curcumin nanofibrous membrane with antibacterial and formaldehyde adsorbable capabilities for lightweight and high-performance air filtration

Functionalization of bio-based nanofibers is the development tendency of high-performance air filter. However, the conventional structural optimization strategy based on high solution conductivity greatly hinders the development of fully bio-based air filter, and not conducive to sustainable development. This work fabricated fully bio-based nanofibrous membrane with formaldehyde-adsorbable and antibacterial capabilities by electrospinning low-conductivity solution for high-performance air filtration and applied to lightweight mask. The "water-like" ethyl cellulose (EC) was selected as the base polymer to "nourish" functional materials of gelatin (GE), β-cyclodextrin (βCD), and curcumin (Cur), thus forming a solution system with high binding energy differences and electrospinning into ultrafine bimodal nanofibers. The filtration efficiency for 0.3 μm NaCl particles, pressure drop, and quality factor were 99.25 %, 53 Pa, and 0.092 Pa-1, respectively; the bacteriostatic rates against Escherichia coli and Staphylococcus aureus were 99.9 % and 99.4 %, respectively; the formaldehyde adsorption capacity was 442 μg/g. This is the first report on antibacterial and formaldehyde-adsorbable high-performance air filter entirely made from bio-based materials. This simple strategy will greatly broaden the selection of materials for preparing high-performance multifunctional air filter, and promote the development of bio-based air filter.

The Rise of Electroactive Materials in Face Masks for Preventing Virus Infections

Air-transmitted pathogens may cause severe epidemics, posing considerable threats to public health and safety. Wearing a face mask is one of the most effective ways to prevent respiratory virus infection transmission. Especially since the new coronavirus pandemic, electroactive materials have received much attention in antiviral face masks due to their highly efficient antiviral capabilities, flexible structural design, excellent sustainability, and outstanding safety. This review first introduces the mechanism for preventing viral infection or the inactivation of viruses by electroactive materials. Then, the applications of electrostatic-, conductive-, triboelectric-, and microbattery-based materials in face masks are described in detail. Finally, the problems of various electroactive antiviral materials are summarized, and the prospects for their future development directions are discussed. In conclusion, electroactive materials have attracted great attention for antiviral face masks, and this review will provide a reference for materials scientists and engineers in antiviral materials and interfaces.

Biodegradable Electroactive Nanofibrous Air Filters for Long-Term Respiratory Healthcare and Self-Powered Monitoring

The concept of triboelectric nanogenerator (TENG)-based fibrous air filters, in which the electroactive fibers are ready to enhance the electrostatic adsorption by sustainable energy harvesting, is appealing for long-term respiratory protection and in vivo real-time monitoring. This effort discloses a self-reinforcing electroactivity strategy to confer extreme alignment and refinement of the electrospun poly(lactic acid) (PLA) nanofibers, significantly facilitating formation of electroactive phases (i.e., β-phase and highly aligned chains and dipoles) and promotion of polarization and electret properties. It endowed the PLA nanofibrous membranes (NFMs) with largely increased surface potential and filtration performance, as exemplified by efficient removal of PM0.3 and PM2.5 (90.68 and 99.82%, respectively) even at the highest airflow capacity of 85 L/min. With high electroactivity and a well-controlled morphology, the PLA NFMs exhibited superior TENG properties triggered by regular respiratory vibrations, enabling 9.21-fold increase of surface potential (-1.43 kV) and nearly 68% increase of PM0.3 capturing (94.3%) compared to those of conventional PLA membranes. The remarkable TENG mechanisms were examined to elaborately monitor the personal respiration characteristics, particularly those triggered large and rapid variations of output voltages like coughing and tachypnea. Featuring desirable biocompatibility and degradability, the self-powered PLA NFMs permit promising applications in the fabrication of ecofriendly air filters toward high-performance purification and intelligent monitoring.