The stereocomplexation between poly(L-lactide)(PLLA)and poly(D-l actide)(PDLA)chains was used to generate strong intermolecular interactions,which could be further enhanced by using high-voltage electric field and intensive mechanical stretching to prompt extreme alignment and refinement of poly(lactic acid)(PLA)nanofi-bers and the formation of electroactive phase(i.e.,β phase,stereoscopic complexation crystal).Due to the aligned nanofiber morphology and excellent electroactivity,the dielectric constant and surface potential of aligned stereocom-plexed PLA(AS-PLA)nanofibrous membranes were increased to 1.68 and 5.4 kV,respectively.Moreover,AS-PLA nanofibrous membranes showed excellent filtration performance and triboelectric performance.In particular,the PLLA/PDLA40 prepared with 40％PDLA addition achieved an ultrafine air particle(PM0.3)removal efficiency of 90.51％and an air resistance of only 240.6 Pa at airflow capacity of 85 L/min,which was significantly superior to pure PLLA fibrous membrane(80.34％,251.4 Pa).In addition,even at high humidity(RH=70％)and high respiratory airflow capacity(85 L/min),the triboelectric nanogenerator(TENG)based filter assembled with AS-PLA nanofibrous membrane as the triboelectric layer showed excellent PM03 removal efficiency of 95.02％,far exceeding that of normal PLA filters(only 89.50％).The increase of electroactivity significantly improved the initial polarization ability and triboelectric performance of the nanofibrous membranes,which could rely on the triboelectric effect to achieve charge regeneration while ensuring the sufficient of the initial charge.It ensures long-term filtration without sacrificing air resistance.
关键词
立构复合化聚乳酸/取向纤维/电活性/摩擦电效应/超细空气颗粒物滤除
Key words
Stereocomplexed poly(lactic acid)/Aligned fiber/Electroactivity/Triboelectric effect/Ultrafine air particles filtration
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