Applying Copper Nanoparticles to Personal Protective Equipment
Channel: Michael B
Date: 2020-05-04

This video demonstrates a simple method of applying copper nanoparticles to personal protective equipment (PPE), such as masks and gloves, in the hopes it can help prevent the spread of infectious microbes.

Metallic copper is “biostatic,” meaning that it has natural properties which destroy a wide range of microorganisms when in contact. The anti-microbial properties of copper have been known since ancient times [1][2]. Modern research shows that copper surfaces and materials reduce the transfer of infectious diseases, including the SARS CoV-2 novel coronavirus [3]. The US Environmental Protection Agency (EPA) has approved the use of copper alloys as "antimicrobial materials with public health benefits.”  Since copper can be blended with textiles [4], it stands to reason that copper nanoparticles applied directly to PPE fabrics can have the same effect [5].

Copper nanoparticles can be applied to fabric quickly and easily, from an aqueous suspension, using a small paintbrush. The solution can be made in any glass container, such as a jar, with common chemicals that are safe to use anywhere.

Equipment:
Two glass containers (jars, drinking glasses, beakers), 
Stove, microwave or hot plate (for heating water), 
Spoon (for measuring & mixing), 
Small paintbrush, 
200 mL water (distilled if available), 
30 g copper sulfate (a pottery glazing), 
20 g ascorbic acid (vitamin c) powder, [6]
The PPE you’re going to treat (mask, gloves).

Procedure:
1. Fill one glass container with 100 mL of water,
2. Dissolve the copper sulfate in the container (stir until all of the solids are dissolved - this will take several minutes), 
3. Fill the other container with 100 mL of HOT water, 
4. Dissolve the ascorbic acid in the hot water (stir until all dissolved - this may also take several minutes and you may want to reheat the solution afterwards), 
5. Pour the hot ascorbic acid solution into the container of copper sulfate solution and stir (the solution will immediately turn a dark greenish-brown), 
6. After a few moments you should notice metallic copper begin to precipitate out of solution and settle at the bottom (it has a salmon color), 
7. Continue stirring or swirling until all of the copper precipitates out (the solution will get lighter eventually turning emerald green while the layer of copper will get thicker), 
8. Allow all the copper particles to settle to the bottom of the container, then slowly decant off the green liquid layer (you can use the other container for this - try not to spill over the copper, a little liquid left behind is ok), 
9. Cover the copper particles with a layer of FRESH water (this prevents the copper from oxidizing in the air), you’re now ready to apply the particles to your mask, 
10. Dip the paintbrush into the layer of copper particles, making sure they adhere to it, and gently paint them on to the outside of the mask. Do this until the entire surface is covered, 
11. Allow the mask to dry.

Efficacy:
The efficacy of this procedure is not known and would require testing. 

Toxicity:
Animal studies have concluded that exposure to aerosolized  copper oxide (CuO) nanoparticles pose no long term health risks [7]. Since the procedure described here is meant to deposit copper on the outside surface of PPE, the masks or gloves themselves should prevent the particles from entering the user’s body.

Longevity: 
Only metallic copper (Cu) possesses antimicrobial properties, which oxidizes rapidly in the atmosphere to form copper oxide and, due to the large surface area presented by nanoparticles, oxidation can occur in just days. Treated PPE should be used immediately or stored in an airtight container until ready for use. 

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References:
1. “Copper.” Wikipedia, Wikimedia Foundation, last modified 2020 March 23, https://en.m.wikipedia.org/wiki/Copper
2. “Antimicrobial Properties of Copper.” Wikipedia, Wikimedia Foundation, last modified 2020 March 22, https://en.m.wikipedia.org/wiki/Antimicrobial_properties_of_copper
3. Campbell, John, PhD, “Viral Aerosols and Surface Survival”, YouTube, published 2020 March 22, https://youtu.be/JNQUHc8wbRc
4. “Reinventing Cotton, Empowering Polymers“,  Argaman Technologies Ltd., retrieved 2020 April 2, https://argamantech.com/about-us/
5. Murray-Smith, Robert, PhD, “Copper and the Coronavirus - Making an Anti-Viral Face Mask”, YouTube, published 2020 March 19, https://youtu.be/a1DK_1DthyM
6. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
7. Gosens, I., et. al., "Organ Burden and Pulmonary Toxicity of Nano-Sized Copper (II) Oxide Particles After Short Term Exposure", US National Library of Medicine, National Institutes of Health, published online 2016 September 2, retrieved 2020 May 5 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4975088/