Al-Coated Conductive Fiber Filters for High-Efficiency Electrostatic Filtration: Effects of Electrical and Fiber Structural Properties

Abstract

Through the direct decomposition of an Al precursor ink AlH3{O(C4H9)2}, we fabricated an Al-coated conductive fiber filter for the efficient electrostatic removal of airborne particles (>99%) with a low pressure drop (~several Pascals). The effects of the electrical and structural properties of the filters were investigated in terms of collection efficiency, pressure drop, and particle deposition behavior. The collection efficiency did not show a significant correlation with the extent of electrical conductivity, as the filter is electrostatically charged by the metallic Al layers forming electrical networks throughout the fibers. Most of the charged particles were collected via surface filtration by Coulombic interactions; consequently, the filter thickness had little effect on the collection efficiency. Based on simulations of various fiber structures, we found that surface filtration can transition to depth filtration depending on the extent of interfiber distance. Therefore, the effects of structural characteristics on collection efficiency varied depending on the degree of the fiber packing density. This study will offer valuable information pertaining to the development of a conductive metal/polymer composite air filter for an energy-efficient and high-performance electrostatic filtration system.

Electrostatic Air Filtration by Multifunctional Dielectric Heterocaking Filters with Ultralow Pressure Drop

“…In these studies, either particles or filters were charged, and so the electrostatic filtration efficiency enhancement was limited. Some researchers installed particle prechargers before conductive filters to strengthen the electrostatic effect. − In these studies, the highest filtration efficiency was 99.99% for 0.03–0.4 μm particles with 4.9 Pa pressure drop at 0.1 m/s face air velocity. , However, the electrostatic shielding limits these filters’ dust-holding capacity because there is no electric force inside the conductive filter material.…”

“…26−29 In these studies, the highest filtration efficiency was 99.99% for 0.03−0.4 μm particles with 4.9 Pa pressure drop at 0.1 m/s face air velocity. 27,28 However, the electrostatic shielding limits these filters' dust-holding capacity because there is no electric force inside the conductive filter material.…”

Transparent Metallized Microfibers as Recyclable Electrostatic Air Filters with Ionization

“…Within this framework, a combined approach utilizing the electrostatic attraction of ESP and fiber-based filters has been introduced for efficient PM capture. − Air ionization and charging of PMs can increase the electrostatic attraction of the particles and thus increase filtration efficiency while circumventing the issue of pressure loss . However, even this hybrid system (combining nanofibers and ESP features) may still suffer from the issues of pressure loss after clogging and poor recyclability when the fiber packing density is high.…”

Effect of electron beam irradiation on filtering facepiece respirators integrity and filtering efficiency

“…The importance of the diffusion mechanism is increasing with decreasing the particle diameter and becomes less as the aerosol particle size increases. It is similar to the electrostatic particle deposition mechanism [18][19][20][21].…”