高等学校化学学报 ›› 2024, Vol. 45 ›› Issue (2): 20230352.doi: 10.7503/cjcu20230352

• 高分子化学 • 上一篇    下一篇

立构复合化聚乳酸纳纤膜的制备及高效滤除PM2.5性能

宋欣译1, 唐梦珂2, 王存民1, 朱金佗1, 黄胜2, 徐欢2, 何新建1()   

  1. 1.中国矿业大学安全工程学院
    2.材料与物理学院, 徐州 221116
  • 收稿日期:2023-08-01 出版日期:2024-02-10 发布日期:2024-01-05
  • 通讯作者: 何新建 E-mail:xinjian.he@cumt.edu.cn
  • 基金资助:
    国家自然科学基金(52174222);江苏省自然科学基金(BK20200661)

Preparation of Stereocomplexed PLA Nanofibrous Membranes with High PM2.5 Filtration Efficiency

SONG Xinyi1, TANG Mengke2, WANG Cunmin1, ZHU Jintuo1, HUANG Sheng2, XU Huan2, HE Xinjian1()   

  1. 1.School of Safety Engineering
    2.School of Materials Science and Physics,China University of Mining and Technology,Xuzhou 221116,China
  • Received:2023-08-01 Online:2024-02-10 Published:2024-01-05
  • Contact: HE Xinjian E-mail:xinjian.he@cumt.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(52174222);the Natural Science Foundation of Jiangsu Province, China(BK20200661)

摘要:

聚乳酸(PLA)纳米纤维在环境友好型纤维过滤材料领域有良好的应用前景, 但受制于其本征螺旋分子链构象和低介电常数的不足, 导致其驻极性能差、 过滤性能(过滤效率及压降)易衰减以及有效服役周期短. 本文将高旋光性的聚L-乳酸(PLLA)和聚D-乳酸(PDLA)溶液共混, 并通过静电纺丝过程的高压静电场诱导C=O基团加速取向极化, 形成高电活性的立构复合晶体(SCs), 显著提高聚乳酸纳纤膜的表面电位、 介电常数及驻极效果等电活性特征, 增大纤维表面静电斥力, 促进PLA纳纤膜(PLA NFMs)的纤维细化, 从而使其压降大幅降低(85 L/min, 209.2 Pa), 过滤PM2.5效率显著提高至96.32%(纯PLLA对比样为72.44%). 更重要的是, 立构复合化PLA纳纤膜(SC-PLA NFMs)的过滤性能受气体流量变化影响较小(10~85 L/min), 当气流增大时, 过滤效率的衰减远远低于纯PLLA, 在高气流下的稳定性使其能更好地满足在空气过滤领域的实际应用需求. 此外, 提高PLA纳纤膜电活性可显著增强摩擦生电输出性能和呼吸振动激发电信号, 为基于人体呼吸的生理特征监测奠定理论基础. 本文研究结果为扩大PLA材料在高性能呼吸防护领域和智能健康监测领域的应用提供了新颖的结构设计策略和可借鉴的解决方案.

关键词: 聚乳酸, 立构复合化, 电活性组分, 驻极性能, 空气过滤

Abstract:

Poly(lactic acid)(PLA) nanofibers have potential applications in the field of environmentally friendly filtration materials, but their intrinsic helical molecular chains conformation and low dielectric constant result in poor electret properties, easy decay of filtration performance(e.g., decreased filtration efficiency, elevated pressure drop), and short effective service life. The formation of highly electroactive stereocomplex crystals(SCs) was achieved by blending poly(L-lactic acid) (PLLA) and poly(D-lactic acid)(PDLA), which was promoted by facilitating the polarization of oriented C=O dipoles induced by the high-voltage electrostatic field during electrospinning. The existence of SCs significantly increased the dielectric constant, electret effect and surface potential of the refined PLA nanofibers. The enhanced electroactivity of PLA nanofibrous membranes(NFMs) enabled significant increase of the PM2.5 filtration efficiency to 96.32%(72.44% for pure PLLA), while providing desirable pressure drops(85 L/min, 209.2 Pa). More importantly, the filtration performance of the electroactive PLA NFMs showed weak relation to the airflow velocity(10—85 L/min), compared to that of the pure PLLA. The excellent stability under increased airflow velocities allows great practical application potential in air filtration field. Moreover, the promotion of the electroactivity of PLA NFMs remarkably enhanced the triboelectricity and electrical signals as stimulated by respiratory vibrations, laying the theoretical foundation for human respiration-based physiological monitoring. This work reveals a new structuring strategy for expanding the application of electroactive PLA in the field of high-performance respiratory protection and intelligent physiological monitoring.

Key words: Poly(lactic acid), Stereocomplexation, Electroactive phase, Electret property, Air filtration

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