Improved Electret Properties of Poly(Vinylidene Fluoride)/Lithium Niobate Nanocomposites for Applications in Air Filters

Abstract

In this work, the electret properties of poly(vinylidene fluoride) (PVDF)/lithium niobate (LiNbO3, LN) nanocomposites are systematically studied. The LN nanoparticles are fabricated by hydrothermal synthesis followed by melt‐reaction. Their morphology and crystalline structures are characterized by scanning electron microscopy (SEM) and X‐ray diffraction (XRD). The PVDF/LN nanocomposite films are prepared by solution casting with N,N‐dimethylformamide (DMF) as the solvent or melt molding. The crystalline phases of PVDF in both pure samples and nanocomposites are checked by XRD and Fourier transform infrared spectroscopy (FTIR). The measurements of the dielectric and electret properties show that the LN nanoparticles significantly increase the dielectric permittivity (ε) and the thermally stimulated discharge current (TSDC) of the samples. Such materials have potential applications including for air filters and power generators. A demonstration shows that after the same charging process, the PVDF/LN nanocomposites can absorb larger amount of polystyrene (PS) foam microparticles or micrometer size test dusts than the pure PVDF.

High‐performance poly(vinylidene fluoride)‐polyamide 11/lithium niobate nanocomposites for the applications in air filtration

“…PA11 pellets (P20 type, Atofena, France) were purchased from Dongguan Meiyi Engineering Plastics Co., Ltd. Guangdong Province, China. LN nanoparticles were synthesized in our previous work …”

“…The TSDC measurements were performed on an electrometer/high‐resistance meter (Keithley 6517B) after charging and being short‐circuited with the procedure used in our previous work . Both sides of the film samples were sprayed by a thin gold layer with thickness of ca .…”

“…They have wide potential applications in capacitors, transducers, memory transistors, power generators, energy harvesters, electrostatic cloak, air filters, and so on . Some natural materials (e.g., wax, rosin, and resin) and inorganic ceramics [e.g., perovskite, barium titanate (BaTiO 3 , BT), and lithium niobate (LiNbO 3 , LN)] have good electret properties . However, the former has the disadvantage of low mechanical strength while the latter has the shortcoming of low mechanical toughness.…”

“…In our previous work, to combine the good electret properties of inorganic ceramics and the polymer materials, the synthesized LN nanoparticles were added into the PVDF matrix to prepare nancomposites . It was found the LN nanofillers could significantly increase the dielectric permittivity ( ε ) and the thermally stimulated discharge current (TSDC) of the materials.…”

“…To solve this problem, another good polymer electret, PA11, with moderate viscosity and excellent fiber‐spinning properties is proposed to be added into PVDF for producing blends . Based on the prepared PVDF‐PA11 blends, the LN nanoparticles synthesized in our previous work will also be added to form nanocomposites . The thermal, mechanical, electret, and fiber‐spinning properties as well as the morphology of the materials will be systematically investigated to see if such materials can have even better applications in air filtration and other related fields.…”