Sciencemadness Discussion Board

DIY C-virus masks. No politics, science only so we don't lose the thread again

Pyro_cat - 23-3-2020 at 05:18

I found a very interesting article

"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."

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

Regular table salt nothing exotic.



clearly_not_atara - 23-3-2020 at 06:31

tl;dr: soak polypropylene microfiber cloth in salt water and let dry. Should work with polyester. With cotton or other porous fibers salt may become embedded in the fiber reducing its exposure and effectiveness.

As a physicist, I've always been surprised that mask design seems to focus on making the holes so small that droplets couldn't get through. Considering dielectric effects the probability of droplet adhesion to a mask via induced dipole-surface attraction should be much higher than a pore-size comparison would indicate (if we assume the mask carries a small but nonzero electric charge, that is). According to this hypothesis, mask failure mostly results instead from viruses still living on the mask which are then transferred to the body.

Even better: make a mask out of a ferroelectric material so it displays a large spontaneous electric field. That should attract droplets very effectively. You still need to kill the viruses, though. The only ferroelectric polymer (worth mentioning) is polyvinylidene fluoride, PVDF.

Fery - 23-3-2020 at 08:31

every even small improvement is very useful
this is just my theoretical thought - wouldn't such filter/mask get wet faster? perhaps this is the reason why low hygroscopic salt is preferred like NaCl and is used only with plastic material clearly_not_atara mentioned (in my country most of people use home made masks from common textile material)
but is concentrated solution of NaCl so powerful to kill virus when you let the filter to dry out?
perhaps if you have a lot of filters just letting them for few days would be safer - the virus won't survive
electromagnetic trap method seems to be promising too - there are almost no virus particles alone, most of them are in droplets of water
UV lamp is allegedly powerful enough for killing the virus too

WGTR - 23-3-2020 at 10:21

I am not an expert on this topic, and my knowledge of biology is very limited. However, if copper metal is known to be anti-microbial, then what about copper salts? Would a small amount of copper sulfate deposited on the mask prevent the virus particles from living for more than a few hours on its surface? Perhaps in addition to NaCl?

It seems that there is a problem with people infecting themselves when they either adjust the mask or take it off/put it back on again. As I understand, this is a big reason why masks are typically single use only.



Attachment: Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1.pdf (707kB)
This file has been downloaded 368 times

[Edited on 20-03-23 by WGTR]

Pyro_cat - 23-3-2020 at 18:04

All I can think of to possibly add to a design right now to a design is to borrow from the idea of motocross goggles

https://www.google.com/search?q=Goggle+Tear-offs+Vs.+Roll-of...

https://freehubmag.com/product-reviews/smith-sweat-x-goggle-...




Pyro_cat - 23-3-2020 at 18:25

Quote: Originally posted by WGTR  
I am not an expert on this topic, and my knowledge of biology is very limited. However, if copper metal is known to be anti-microbial, then what about copper salts? Would a small amount of copper sulfate deposited on the mask prevent the virus particles from living for more than a few hours on its surface? Perhaps in addition to NaCl?

It seems that there is a problem with people infecting themselves when they either adjust the mask or take it off/put it back on again. As I understand, this is a big reason why masks are typically single use only.



https://www.google.com/search?q=are+copper+sulfate+crystals+... +toxic

Need like a pavlov's dog electric shock system to train people dont touch your face. Maybe not a a shock but some kind of alert feedback.


"Copper is one of the most common biocides used in the recreational marine industry. A biocide typically prevents the growth of hard fouling organisms such as acorn barnacles and zebra mussels. In general, an antifouling paint will be more effective if it has a higher copper content."

cuprous oxide antifouling paint toxicity, I know when they work on boats they treat that stuff as toxic waste.,

I just found this

"CuVerro® Copper integrates seamlessly into the manufacturing process, offering products that are reliable and durable. These products are invaluable to end users where high-touch areas present health risks, such as hospitals, or in public places needing to stay germ-free in between cleanings, like fitness centers.

"High-touch areas present health risks because of surface contamination in environments from healthcare to public and private spaces. CuVerro bactericidal copper continuously kills 99.9% of bacteria1 within two hours of exposure between regular cleanings and can help keep a range of risk-prone surfaces continuously clean from bacteria."

https://cuverro.com/product-showcase

And this

https://health.clevelandclinic.org/do-anti-fatigue-copper-co...

Maybe those copper socks people could tool up to make masks instead ?



[Edited on 24-3-2020 by Pyro_cat]

Twospoons - 24-3-2020 at 01:41

Fine weave copper cloth is made for EMI shielding. Its quite flexible, as its made to stick over oddly shaped bits of electronics.A layer of that on the outside might make a good first defense layer, as there seems to be quite a bit of research showing copper's ability to kill viruses and bacteria.

RogueRose - 24-3-2020 at 02:20

I've seen some scuba masks which are full face masks made of polycarbonate that have a snorkel that attaches to the top of the unit and extends about 10". They are actually pretty nice and would work nicely as a saftey face mask for doing lab work or work in a shop (like grinding, cutting, etc).

The snorkel could be modified to put a filter housing on. IDK if the mask has a 1 way check valve, it would seem it would need one for this to work properly.

As far as material for filtering, I had mentioned furnace filters weeks ago with MERV 15 being nearly equal to N95 and MERV 16 being better, but they are pretty expensive and getting difficult to find.

I'd suggest looking for vacuum bags & filters, specifically HEPA filter bags. Also air filters/cartridges/bags for air filters and dust collectors can have down to sub micron filter ratings, some of the bags are very large (3-15ft x 2-12" diameter & much less expensive than furnace filters).

How long does UV take to kill viruses? I would think that a chamber with a UV light that is large enough to have a dwell time of a few breaths as the air moves into & through the chamber might be adequate. I think UVC is the spectrum that kills best. Also maybe lining the chamber with reflective mylar would increase the effectiveness of any light used?? I'd think an LED might be efficeient enough to use as a portable solution for shorter periods and things like 7.2-20v lithium tool batteries could be used to power it, possibly with a voltage converter to get the correct voltage.

(note: When China announced the outbreak - before the US did anything & China was looking for masks, I looked for MERV 15 & 16 on amazon and there were 30-50 options with lots of stock. About 10-14 days later there was only 1 product left on Amazon that was MERV 15, not even listings of out of stock items and most places weren't even listing anything. IDK if people bought these and shipped them to China or what, but it's highly suspicious IMO.

[Edited on 3-24-2020 by RogueRose]

phlogiston - 24-3-2020 at 03:23

Quote: Originally posted by RogueRose  

How long does UV take to kill viruses? I would think that a chamber with a UV light that is large enough to have a dwell time of a few breaths as the air moves into & through the chamber might be adequate. I think UVC is the spectrum that kills best.
[Edited on 3-24-2020 by RogueRose]


Short wavelength UV also generates ozone, which you do not want to inhale in significant quantities/prolonged periods of time.

Pyro_cat - 28-3-2020 at 18:56


I dont know.

How do you build a ventilator ? Show me I will build one and save a life.

I have made lightning bolts from junk in the basement and shit explode from the dollar store

I think I am smart wish I could help.

what sucks is its about behavior STOP FUCKING CLOSE TALKING

If it cant spread it dies. Thats it., thats its fatal flaw.

Oh sure people people get all bugged out about our discussions in energetic materials OMG thats so dangerous !

Meanwile on the news it says yo practice social distancing.... and they dont.


Bet 99% of the public would stay away from an ounce of nitroglycerin but a potentially deadly virus "it wont happen to me"

This is not a science problem its a behavior problem .

What would Mr Spock say about this ?

Its totally illogical human behavior, just follow the damn rules and the virus is extinct in a few weeks

Its not a science problem its a behavior problem

Behavioral science .. that I dont get.


[Edited on 29-3-2020 by Pyro_cat]

Pyro_cat - 28-3-2020 at 19:30



Ya screw all this I am going to watch Star Trek

Sucks I already did voyager but its been so long since I have watched the originals I forgot enough to remember what happens next.

https://www.inc.com/kevin-daum/50-star-trek-inspiring-you-to...

Pyro_cat - 1-4-2020 at 08:38

Should I put my cash in the toaster oven ?

Search Results
451 degrees Fahrenheit
But despite the type of paper, the chemical and physical properties are roughly the same. Ignition temperature is the temperature at which something catches fire and burns on its own. The ignition temperature of paper is 451 degrees Fahrenheit, or 233 degrees Celsius.


This bacteria, thermus aquaticus thrives at temperatures of 70°C (160°F) but can survive temperatures of 50°C to 80°C (120°F to 175°F). A few years after these were discovered, other bacteria were found living under even more extreme conditions.

Ya well CV wont do well at 300 F

No, I am going to do 230, just above boiling bio sceince is not my thing but no way it survives that


Kept using my clean twenties now I have all this change.


I hate this, I always kind of liked when bad weather was coming but F germs this sucks.

SWIM - 1-4-2020 at 10:42

Quote: Originally posted by Twospoons  
Fine weave copper cloth is made for EMI shielding. Its quite flexible, as its made to stick over oddly shaped bits of electronics.A layer of that on the outside might make a good first defense layer, as there seems to be quite a bit of research showing copper's ability to kill viruses and bacteria.


I suspect the copper might work better if woven in with an absorbent fiber.

The spittle, mucus, and other ejecta from the infected might not be retained long enough by a layer of copper and tend to just get sucked through to the layer below.

If the copper is distributed in an absorbant it might work on droplets retained by fibers nearby because of that whole capillary action thing.

As for UV, I don't think UV above 250 Nm or so makes much ozone.
Ozone producing UV sources I've seen usually have a secondary peak around 180 or 190.

I believe this secondary peak is either filtered out or converted by some coating in the bulb in non-Ozone UVC lights.

There are some really tiny UVC rigs available on ebay. Little 12 volt jobs with bulbs the size of a felt tip marker. and very compact ballast packages.

But I'd sure hate to have my batteries die in the middle of a coughing crowd.

Twospoons - 1-4-2020 at 12:41

I agree re the copper. Best, I think, would be copper ions or particles bonded into cotton fibers somehow. Any method that doesn't need exotic things like PdCl2 ?
https://www.karger.com/Article/FullText/89211
That paper is about the 2006 SARS virus, but thoughts are that covid is very similar. The key takeaway from that is that some virus particles survive UV treatment, so implementing UV may not only be difficult, but ineffective too.

[Edited on 1-4-2020 by Twospoons]

Pyro_cat - 1-4-2020 at 17:49


I would love to have a high powered UV "flashlight" right about now to just clear any surface of contaminants right about now.

I just blew up my 24 Oz beer by using the plumber torch to sterilize the top. The top popped of and all I did was give it a quick swirl and just a little more to "make sure". Separated on the edge not the tab.

Happened quick, I am an old pyro cat thrown beers in the campfire it takes time, totally misjudged this one.

Been watching the public many are starting to take this serious , I always had a bit of germaphobia so change came easier.

I was covering my face about a week before others started.

This "shortage" of masks. Oh come on, Hepa Ac filters or vacuum cleaner bags DIY, some cotton fabric behind to filter any bad fibers. Then fabric in front to be "stylish" for this ordeal.


Pyro_cat - 1-4-2020 at 18:00


What we need is a germ to go after the germ thats messing with us.

Thinking of the story of penicillin.




[Edited on 2-4-2020 by Pyro_cat]

Twospoons - 1-4-2020 at 18:41

UVC led torch

Would that do what you want?
I've used their other LEDs to make art studio lighting for my wife, and they're really good, so I'd actually trust this one to be UVC.

[Edited on 2-4-2020 by Twospoons]

Morgan - 1-4-2020 at 18:42

Quote: Originally posted by RogueRose  
I've seen some scuba masks which are full face masks made of polycarbonate that have a snorkel that attaches to the top of the unit and extends about 10". They are actually pretty nice and would work nicely as a saftey face mask for doing lab work or work in a shop (like grinding, cutting, etc).

The snorkel could be modified to put a filter housing on. IDK if the mask has a 1 way check valve, it would seem it would need one for this to work properly.

As far as material for filtering, I had mentioned furnace filters weeks ago with MERV 15 being nearly equal to N95 and MERV 16 being better, but they are pretty expensive and getting difficult to find.

I'd suggest looking for vacuum bags & filters, specifically HEPA filter bags. Also air filters/cartridges/bags for air filters and dust collectors can have down to sub micron filter ratings, some of the bags are very large (3-15ft x 2-12" diameter & much less expensive than furnace filters).

How long does UV take to kill viruses? I would think that a chamber with a UV light that is large enough to have a dwell time of a few breaths as the air moves into & through the chamber might be adequate. I think UVC is the spectrum that kills best. Also maybe lining the chamber with reflective mylar would increase the effectiveness of any light used?? I'd think an LED might be efficeient enough to use as a portable solution for shorter periods and things like 7.2-20v lithium tool batteries could be used to power it, possibly with a voltage converter to get the correct voltage.

(note: When China announced the outbreak - before the US did anything & China was looking for masks, I looked for MERV 15 & 16 on amazon and there were 30-50 options with lots of stock. About 10-14 days later there was only 1 product left on Amazon that was MERV 15, not even listings of out of stock items and most places weren't even listing anything. IDK if people bought these and shipped them to China or what, but it's highly suspicious IMO.

[Edited on 3-24-2020 by RogueRose]


COVID: SPAIN: HOSPITALS CONVERT SCUBA MASKS TO PPE
https://www.wfmz.com/news/cnn/editors-choice/covid-spain-hos...


[Edited on 2-4-2020 by Morgan]

mayko - 5-4-2020 at 09:55

sewing machine go brrrrrrrrr

SewingMachineGoBrrrrrrrrrr_smol.jpg - 102kB

I'm using this pattern, though there are plenty of others.
https://www.masksoflove.org/citizen-mask-pattern.html

Simple cloth masks mostly protect others from oneself, not the other way around. Far from perfect and a complement to other strategies, not a substitute - but better than no mask at all.

zed - 6-4-2020 at 14:55

Iodine is purported to kill the Corona virus very quickly.

Perhaps paper masks treated with a 2% Iodine tincture and dried, will quell some infection problems.

Iodine deposited on the outer mask surfaces via spray, then dried, should "toast" infectious droplets, while causing no harm to the wearer.

I recently ordered a few hundred grams of Iodine for that purpose. There is a deadly shortage of n95 masks in the USA, and most masks are too fragile for ordinary disinfection procedures.

BromicAcid - 6-4-2020 at 15:51

I've been waiting for the people in this article to release their mask design:

https://www.businessinsider.com/homemade-mask-using-hydro-kn...

zed - 7-4-2020 at 08:40

https://pubs.acs.org/doi/suppl/10.1021/acssuschemeng.7b01160...

If this links up properly, it reveals an interesting approach to producing filtering paper from paper towels.

I don't know how the guys are "spinning" gelatin though. They make it seem simple, and it probably isn't.

I'm familiar with blue shop towels. And, I have been longingly thinking about them. Alas they aren't close to me. They are sequestered at the nearest auto-parts store. Might as well be on the moon.

The authors above suggest "Bounty" as being thickest of the easily available towels, and also having the smallest "pores".

[Edited on 7-4-2020 by zed]

andy1988 - 8-4-2020 at 00:30

Quote: Originally posted by zed  
https://pubs.acs.org/doi/suppl/10.1021/acssuschemeng.7b01160...

If this links up properly, it reveals an interesting approach to producing filtering paper from paper towels.

I don't know how the guys are "spinning" gelatin though. They make it seem simple, and it probably isn't.

Link didn't work for me, this one works: https://pubs.acs.org/doi/suppl/10.1021/acssuschemeng.7b01160

That is a neat idea. Paper towel as a substrate and electrospin something on top.

Open source designs exist for both electrospinning machines and syringe pumps.

mayko - 15-4-2020 at 19:05

Mind you, this is a preprint and has not been reviewed, but the it looks credible enough to me in a fast-moving situation.

Quote:

The science around the use of masks by the general public to impede COVID-19 transmission is advancing rapidly. Policymakers need guidance on how masks should be used by the general population to combat the COVID-19 pandemic. Here, we synthesize the relevant literature to inform multiple areas: 1) transmission characteristics of COVID-19, 2) filtering characteristics and efficacy of masks, 3) estimated population impacts of widespread community mask use, and 4) sociological considerations for policies concerning mask-wearing. A primary route of transmission of COVID-19 is likely via small respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals. Reducing disease spread requires two things: first, limit contacts of infected individuals via physical distancing and contact tracing with appropriate quarantine, and second, reduce the transmission probability per contact by wearing masks in public, among other measures. The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at stopping spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Thus we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.


Howard, J.; Huang, A.; Li, Z.; Tufekci, Z.; Zdimal, V.; van der Westhuizen, H.; von Delft, A.; Price, A.; Fridman, L.; Tang, L.; Tang, V.; Watson, G.L.; Bax, C.E.; Shaikh, R.; Questier, F.; Hernandez, D.; Chu, L.F.; Ramirez, C.M.; Rimoin, A.W. Face Masks Against COVID-19: An Evidence Review. Preprints 2020, 2020040203 (doi: 10.20944/preprints202004.0203.v1).

https://www.preprints.org/manuscript/202004.0203/v1

Pyro_cat - 17-4-2020 at 23:28

Quote: Originally posted by zed  
Iodine is purported to kill the Corona virus very quickly.

Perhaps paper masks treated with a 2% Iodine tincture and dried, will quell some infection problems.

Iodine deposited on the outer mask surfaces via spray, then dried, should "toast" infectious droplets, while causing no harm to the wearer.

I recently ordered a few hundred grams of Iodine for that purpose. There is a deadly shortage of n95 masks in the USA, and most masks are too fragile for ordinary disinfection procedures.


I think you would need the type of mask with a one way valve to let the moist exhale out and only draw air in so it stays dry.

It just sucks cause this mindless virus could be so easily defeated but about about half the people where I am are so careless.

Maybe only a third now but still.

Close talker types with no mask want to run up on me I just look at them like don't and they get the message.