What sort of filter material self sterilizes?

Question

I am working on a self-inspired project to design a cheap mask for my community.

So far the problem with the common masks is that they just stop a percentage of materials (droplets) to get in but it doesn't kill the virus, so there's still a high chance of getting infected through touching the masks. I was thinking about adding a filter (tissue-like material soaked in sanitizers/alcohol) to something like a scuba mask for people who don't have PPE but still have to go outside.

The filter should somewhat purify the air (I thought about unidirectional valves to separate breathe-in and out air but think that would be costly and currently I don't know any cheap solution for such a mechanism).

Some links that support soap water/ hand sanitizers can kill/neutralize covid-19 virus.

https://www.weforum.org/agenda/2020/03/coronavirus-soap-covid-19-virus-hygiene/

https://jamanetwork.com/journals/jama/fullarticle/2763533

The problem is that alcohol or soap can be toxic and breathing it continuously can result in some health issues. [Is soap water vapor also harmful to breathe in?]

Now, I was thinking about adding another internal filter to reduce the alcohol level/ soap water content by drying it out. I know silica gel can absorb water but will it work on soap-water and alcohol and is it okay to breathe in after air has been passed through silica? Can salt be used?

As this is a medical network, I just need some suggestions if this is even feasible and will help at all or not (without causing any medical health problems). What would be the most appropriate set of chemical agents that I can place in filter 1 and filter 2 so that the air is purified, the viruses are killed/neutralized, the air is breathable without any health hazard for a 6-8 hours period. (The filters will be replaced after one use if needed)

I would appreciate it if you can link any papers/references so I can get a better idea to back my concept.

I'm not interested to reinvent the wheel, just refer me to the existing filtration system which may be somewhat applicable to me so that I can start my studies, that is enough, as I'm not from this background that's what I need to know to get started. No one is asking to make an invention here, for me this seems to be general knowledge for someone in the field of chemistry, toxins; correct me if I'm wrong. if I was, I wouldn't have posted this on a public forum in the first place, hope you understand.

Answer 1

You could look at the open source nano-copper impregnated filter material which is said to self sterilize given enough time.

In the study by Borkow et al (2007)7, a 2.5 cm filter was designed containing a 2 cm thick top layer of 500 mg of non-woven polypropylen impregnated with 5% copper oxide particles. This study had a control that was non-woven polypropylen copper-free as a control. Diffusion of viruses through filters containing copper oxide resulted in a significant reduction in viral titers from 0.47 log10 to 4.6 log10 depending on the virus analyzed.

According to this study, it can be concluded that a non-woven fabric filter impregnated with copper oxide is capable of generating filtration of viruses of different types, including respiratory viruses, as can be seen in the attached table.

And there's the salt impregnated masks that was mentioned in another question here.

The salt coating on the fiber surface dissolves upon exposure to virus aerosols and recrystallizes during drying, destroying the pathogens. When tested with tightly sealed sides, salt-coated filters showed remarkably higher filtration efficiency than conventional mask filtration layer, and 100% survival rate was observed in mice infected with virus penetrated through salt-coated filters. Viruses captured on salt-coated filters exhibited rapid infectivity loss compared to gradual decrease on bare filters. Salt-coated filters proved highly effective in deactivating influenza viruses regardless of subtypes and following storage in harsh environmental conditions. Our results can be applied in obtaining a broad-spectrum, airborne pathogen prevention device in preparation for epidemic and pandemic of respiratory diseases.

References

7. Borkow G, etal., (2007) Neutralizing Viruses in Suspensions by Copper Oxide-Based Filters. Antimicrobial Agents and Chemotherapy, p. 2605–2607

https://www.nature.com/articles/srep39956