Interchangeable Filter For Virus Filtration and Inactivation

The COVID-19 pandemic has caused a multi-scale impact on people from all walks of life, requiring mandatory use of prevention measures like use of face masks to reduce the probability of exposure to the aerosolized virus. In present study, we propose a novel filter with three unique layers. The outermost layer is a spun-bond PPE coated with water-based, nano-engineered hydrophobic and lipophobic coating to prevent adherence of droplets virus to the mask. The second layer is a non-woven layer. The middle layer is a copper mesh coated with diamond-like carbon coating capable of virus inactivation. The last two layers are non-woven layers, close to the mouth. Pressure resistance across this proposed configuration was simulated and validated experimentally showing a good agreement, with error less than 30% and novel filter shows higher breathability as compared to medicals masks. This experiment is also used for determining the viscous and inertial resistance coefficients, crucial in numerical simulation studies of masks. We use ANSYS FLUENT and model filter as porous media. We test the filter against MS2 bacteriophage virus, comparing the viral log reduction to disposable medical mask. The filter shows 90% efficiency against the aerosolized MS2 virus. The DLC layer is responsible for inactivation of virus stuck in the filter fibers, making the filter reusable in nature. This is tested for inactivation over 2 hours of time. In a non-woven fiber, the particulate removal takes place according to different mechanisms depending on particle size, namely, straining or sieving, inertial impaction, interception, and Brownian diffusion. Different grades of non-woven layers affect the filtering efficiency. Two grades of non-woven layers, namely, 50g/m² and 150g/m² are tested against MS2 virus to quantify the filtration efficiency based on non-woven layers. This helps us shed light on how the proposed filter can prevent and inactivate the nanoscale pathogens.