Electrically Responsive Coarse Filters Endowed by High-Dielectric-Constant Surface Coatings toward Efficient Removal of Ultrafine Particles and Ozone

Abstract

Ambient ultrafine particles (UFPs) cause severe health threats, and UFPs can transport in indoor environments through building envelopes. In building HVAC (heating, ventilation, and air conditioning) systems, fibrous filtration has been extensively used to resist particulate matter. However, there is an intrinsic conflict between fibrous filters’ high filtration efficiency and low air resistance. Herein, we designed a dielectric-coated fiber structure and fabricated electrically responsive coarse filters to remove UFPs by utilizing the Coulomb force between the charged particles and the polarized fibers. The electrical responsiveness endowed the filters with an excellent performance for the removal of UFPs. With the synergistic improvement of particle precharging and filter polarization, the UFPs’ removal efficiency of the coated filter increased from ∼0% to the highest of 90.50%, with ultralow ∼13.0 Pa air resistance at 1 m/s face air velocity, which ensured a considerable filtration performance even under large face air velocity. Furthermore, the combination of MnO2 and polyurethane (PU) filters performed with the ability to remove the unwanted ozone generated by particle precharging. The promising features give these filters excellent potential for use in energy-efficient electrostatic air-cleaning devices, thus achieving a healthy and sustainable environment.

Photocatalytic inactivation technologies for bioaerosols: advances and perspective

“…Metallic meshes are frequently used in commercial air purifiers as coarse filters. 32,34,124 As photocatalysts carriers, stainless meshes were coated with ZnO photocatalysts through the painting method for bioaerosol photocatalytic inactivation. 125 The pore size of two-dimensional-sheet meshes is even larger than 500 μm, allowing light transmission and avoiding blockage.…”

Research of electret air filter: A review

“…Electrostatically assisted air (EAA) filter is an effective way to significantly augment the removal efficiency based on a low‐efficiency coarse filter without deteriorating air permeability when applied under a large flow rate, thus achieving high efficiency, low air resistance, and large particle loading capacity at the same time 63 . EAA can increase the filtration efficiency by polarizing particles and filters.…”

Amino groups modified MnOx‐PUF applied in indoor air purification: removing formaldehyde at room temperature

“…[19] For example, Wang et al synthesized a layered δ-MnO 2 , [20] which can remove the HCHO from 250 ppm to 30 ppm at 30 °C within 150 min. In order to improve the catalytic activity and avoid the pollution of powder solid particles, the materials with porous structure are used as the carrier of MnO x catalyst, such as various foams [21][22][23] or fibrous materials. [24][25][26] Wang et al prepared MnO x based on the carrier material of polyethylene terephthalate (PET) fibers by in situ deposition method.…”