As you know there are many challenges today at the outbreak of the Corona Virus. One is a cost-effective face mask to reduce the rate of infection. At this point of time there is a shortage in such effective masks for the medical stuff in most countries and definitely for the general public that cannot afford such expensive masks even if available commercially. Therefore we, at the Shoseyov lab, have launched an international effort to develop a simple homemade effective mask.
Recently it has been published1 that filter paper made from 100% nanocellulose (NFC-Nano Fibrillar Cellulose) has the capacity to efficiently remove even the smallest viruses, i.e., up to 99.9980–99.9995% efficiency (Figure 1). We suggest to develop and optimize a home-made process to produce such a mask.
Figure 1: SEM image of a nanocellulose filter paper postfiltration of simulated waste water. Deposited solids from the waste water are visible on top of the filter structure; Gustafsson, O., Manukyan, L., Mihranyan, A., Global Challenges 2018, 2,800031.
In order to share and learn from each other experiments and experience, we have created an online google-spreadsheet so everybody can input his/her tested protocol and results - can be accessed here.
Our goal is to come up in the next couple of weeks with a simple video clip protocol that will be translated to as many languishes as possible and make it available to the general public for free. We encourage everyone, members of the BCN community, researchers from other relevant fields and even hobbyists, to take part in this international initiative and assist in our fight through this global pandemic (we are all grounded to our homes anyway…).
The initial protocol we suggest for the experiments is based on these assumptions:
- Nanocellulose paper can be produced at home by simply growing acetobacter on water diluted wine, as well as other simple substrates.
- TiO2 is an effective photocatalyst that if integrated into the filter could kill the virus.
The basic home protocol we suggest is as follows:
- Take a glass of wine and add 2 glass of water (tap water should be fine or better boiled water). Mix vigorously to add oxygen and pour into glass or Pyrex tray. Insert cotton yarn into the medium (make sure it floats and do not sink) while leaving 2 loops from both ends of the tray (this will be used as the mask handles). Put in worm and ventilated place at temperature ranging from 25°C to 30°C. A thick floating pellicle will appear 2-4 days later
- Once a pellicle appears sprinkle 1 spoon of whitened sugar powder used for donuts (Figure 2), or any other source of food grade TiO2 on top of the pellicle and let fermentation continue for one more day.
- Add 1 spoon of detergent (used to wash dishes) to the medium and put in the oven at 110°C for 1 hour to lyse the cells.
- Wash extensively with water and lay over a solid frame covered by cloth or non-woven wipe that match your face until dry (other home-made drying methods are welcome). Make sure the TiO2 side is facing outwards.
Figure 2: Whitened sugar powder, as an example for food-grade TiO2 source; https://thenovicechefblog.com/mini-powdered-sugar-doughnuts/
Figure3: Images from our team ongoing experiments
- Gustafsson, O., Manukyan, L., Mihranyan, A., Global Challenges 2018, 2,800031; https://doi.org/10.1002/gch2.201800031