Efficient and Robust Metallic Nanowire Foams for Deep Submicrometer Particulate Filtration

Abstract

The on-going COVID-19 pandemic highlights the severe health risks posed by deep submicron sized airborne viruses and particulates in the spread of infectious diseases. There is an urgent need for the development of efficient, durable and reusable filters for this size range. Here we report the realization of efficient particulate filters using nanowire-based low-density metal foams which combine extremely large surface areas with excellent mechanical properties. The metal foams exhibit outstanding filtration efficiencies (>96.6%) in the PM0.3 regime, with potentials for further improvement. Their mechanical stability and light weight, chemical and radiation resistance, ease of cleaning and reuse, and recyclability further make such metal foams promising filters for combating COVID-19 and other types of airborne particulates.

Magnetic structure and internal field nuclear magnetic resonance of cobalt nanowires

“…For the 50 nm diameter nanowires, 6 μm thick track-etched polycarbonate membranes (PC) with a pore density of 6 × 10 8 cm −2 were used, 39 after coating with Au back electrodes. For the 200 nm diameter nanowires, 60 μm thick anodized aluminum oxide (AAO) membranes with a pore density of 10 9 cm −2 were used, 40 after coating with Cu back electrodes.…”

“…Electrolytes formulation used in this project were adapted from prior studies. 5,40,41 For the additive-free electrolyte, a Watts-like 42 electrolyte with Ni replaced by Co precursors was employed. Specifically, the electrolyte was composed of 240 g L −1 CoSO 4 ·7H 2 O + 50 g L −1 CoCl 2 ·6H 2 O + 40 g L −1 H 3 BO 3 .…”

A Low-Cost Portable Apparatus to Analyze Oral Fluid Droplets and Quantify the Efficacy of Masks

“…Better understanding of aerosol physics may permit specialized mask designs specifically suited towards blocking the user's droplets from escaping when speaking, coughing, and sneezing. Furthermore, such a setup would expedite the process of developing and testing revolutionary material, such as copper foam [31], that would mitigate the environmental impact of widespread face mask use. Additionally, this setup would be useful in areas with limited resources to not only demonstrate the mechanism of virus spread, but also for the aforementioned mask evaluation purposes.…”

Demonstration of Hollow Fiber Membrane-Based Enclosed Space Air Remediation for Capture of an Aerosolized Synthetic SARS-CoV-2 Mimic and Pseudovirus Particles

“…Furthermore, some have shown easy regeneration/reuse of HFMs in filtering aerosols. , To our knowledge, no studies have demonstrated viral aerosol capture using HFM modules with differing properties. Efforts to design filters and methods for removing/deactivating viral aerosols have increased in light of the current coronavirus pandemic. − We sought to use commercially available HFMs (polypropylene, PVDF, and polyether sulfone) for quickly deployable and effective aerosol filtration to curb the spread of the COVID-19 pandemic rather than developing new membranes or other novel solutions that will take time to reach the public.…”