Xingyu Zhao, Kunpeng Ruan, Hua Qiu*, Yali Zhang and Junwei Gu*. Polyacrylonitrile nanofiber reinforced polyimide composite aerogels with fiber-pore interpenetrating structures for sound absorption, air filtration and thermal insulation. Composites Science and Technology, 2023, 244:110275. 2022IF=9.1
https://doi.org/10.1016/j.compscitech.2023.110275
Abstract
Prolonged noise pollution and its induced vibration would not only lead to the failure of instruments and equipment, but also endanger human health. In this work, with water-soluble polyamide acid (PAA) as the matrix and polyacrylonitrile nanofiber (PANNF) as the reinforcement, PANNF reinforced polyimide (PANNF/PI) composite aerogels with fiber-pore interpenetrating structures are fabricated by the method of “homogeneous mixing, freeze-drying and heat treatment”. PANNF that intersperses among pores can effectively inhibit the shrinkage of PI aerogels and enhance sound absorption and mechanical properties. With PANNF dosage of 10 wt %, the composite aerogels own the excellent sound absorption performance, with noise reduction coefficient (NRC) of 0.398, and average sound absorption coefficient (SAC) of 0.913 in the frequency range of 2000~6300 Hz. The composite aerogels also have excellent mechanical properties, with Young’s modulus of 12.42 kPa, stress loss of 3.64% and energy loss coefficient of 0.203. 10 wt% PANNF/PI composite aerogels also possess satisfying air filtration performance (97.2% filtration efficiency for PM2.5, quality factor (QF) value of 0.0396 Pa-1; and 99.4% filtration efficiency for PM10, QF value of 0.0567 Pa-1) and thermal insulation performance (thermal conductivity coefficient as low as 0.036 W/(m?K)).
長時間的噪聲污染及其帶來的共振問題不僅會導致儀器設備失效，還會危害人類健康。本文以二氨基二苯醚（ODA）和均苯四甲酸二酐（PMDA）為單體并經三乙胺（TEA）改性合成的水溶性聚酰胺酸（PAA）為基體、聚丙烯腈納米纖維（Polyacrylonitrile nanofiber，PANNF）為增強體，經均勻混合、冷凍干燥和熱處理制得具有纖維-孔互穿結構的PANNF增強聚酰亞胺（PANNF/PI）復合氣凝膠。穿插在孔道間的PANNF可以有效抑制PI氣凝膠的收縮且不影響其孔隙率與孔壁厚度，協同提升PANNF/PI復合氣凝膠的吸聲性能和力學性能。當PANNF用量為10 wt%時，PANNF/PI復合氣凝膠表現出最佳的吸聲性能，優異的力學性能、空氣過濾性能和隔熱性能。其降噪系數（NRC）為0.398，2000~6300 Hz頻率范圍內平均吸聲系數為0.913；楊氏模量為12.42 kPa、經歷1000次壓縮循環（最大應變為50%）后應力損耗為3.64%、能量損耗系數為0.203；對PM2.5過濾效率為97.2%、對應品質因子（Quality factor，QF）為0.0396 Pa-1，對PM10過濾效率為99.4%、對應QF值為0.0567 Pa-1；導熱系數為0.036 W/m·K。
論文亮點
1. 采用“均勻混合-冷凍干燥-熱處理”法制備出具有纖維-孔互穿結構的PANNF/PI復合氣凝膠。當PANNF用量為10 wt%時，PANNF/PI復合氣凝膠具有最佳的吸聲性能，其NRC為0.398、2000~6300 Hz頻率范圍內平均吸聲系數為0.913；
2. 當PANNF用量為10 wt%時，PANNF/PI復合氣凝膠具有優異的力學性能。其楊氏模量為12.42 kPa、且在經歷1000次壓縮循環（最大應變為50%）后應力損耗為3.64%、能量損耗系數為0.203；
3. 當PANNF用量為10 wt%時，PANNF/PI復合氣凝膠具有優異的空氣過濾性能（對PM2.5過濾效率為97.2%、QF值為0.0396 Pa-1；對PM10過濾效率為99.4%、QF值為0.0567 Pa-1）和隔熱性能（導熱系數為0.036 W/(m·K)）。
第一作者：趙興宇
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