Preparation of Self-Polarized Stereocomplexed PLA Nanofiber Membrane and the Active Capturing of Particulate Matters

Fine particulate matter (PMs) can carry harmful substances such as viruses, bacteria and heavy metals, which jeopardize human health. Wearing respiratory protective equipment is the most effective way to protect the human body from PMs. Traditional respiratory protective masks are usually manufactured using corona electret-treated melt-blown polypropylene (PP), but the non-degradable nature of this material might cause a heavy burden on the environment. In this work, the biodegradable polylactic acid (PLA) was used to enhance the electret effect of PLA by using the stereocomplexation of molecules with different spinodal properties, and the self-polarized ferroelectric material barium titanate (BTO) nanoparticles and the nucleating ethylene bis stearamide (EBS) were added in order to improve the electroactivity and dielectric properties of PLA. Self-polarized PLA nanofibrous membranes (NFMs) were prepared by electrostatic spinning technique with irregular groove-like structure. The extremely fine fiber diameter (268 nm) and enhanced surface potential (1.74 kV) and dielectric properties (1.21) of self-polarized PLA NFMs were exhibited. Meanwhile, the self-polarized PLA NFMs also shown friction electrical properties, with an open-circuit voltage of 39.6 V and a short-circuit current of 431.4 nA. The high-voltage, low-current operation mode allows the self-polarized PLA NFMs to be used in special environments, such as mine, without negative effects. Notably, the self-polarized PLA NFMs exhibited excellent PMs capturing effect and low pressure drop (>96%, 192.7 Pa, 85 L/min). The preparation of self-polarized PLA NFMs provided a possible direction for the development of PLA-based filtration materials.