IO, Bandung – The Covid-19 pandemic has had another crucial impact. The widespread use of medical masks and disposable masks has contributed to an increase in medical waste and environmental pollution.
Even though there are alternatives to the use of cloth masks by masks that can be used over and over again, it turns out that these are less effective at defending against viruses from droplets or aerosols. Therefore, the use of medical masks remains a recommendation to impair the rate of transmission of Covid-19.
This challenge prompted five students of the Faculty of Mathematics and Natural Sciences, Padjajaran University (Unpad), Bandung, to develop research ideas for cloth masks with similar effectiveness to medical masks. Research by Rifky Adhia Pratama (Chemistry), Riska Kurniawati (Biology), Farrel Radhysa Muhammad Zahdi (Biology), Didi Permana (Physics), Muhammad Naufal Ardian (Physics) under the guidance of three lecturers, namely Diana Rakhmawaty Eddy, Allyn Pramudya Sulaeman, and Yudha Prawira Budiman.
The team from the Faculty of Mathematics and Natural Sciences initiated the idea of a mask with a combination of 60% cotton and 40% polyester, coated with a layer of graphene from rice husks. This idea is realized through research that is based on literature. When interviewed by the Padjadjaran University Public Communication Office, last month, Rifky as the team leader explained that masks with a composition of 60% cotton and 40% polyester are apparently able to inhibit droplets and aerosols from outside, especially with a layer of graphene on the surface of the mask.
Based on literature, graphene layers give rise to superhydrophobic or super water-repellent properties. The results of the contact angle measurement show that the graphene layer has a value of approximately 141 degrees. This value exceeds the reference for a material to be said to be hydrophobic, which is 90 degrees. “Because the value exceeds 90 degrees, we call it superhydrophobic,” he said.
Judging from the nature of the spread of the SARS-CoV-2 virus, the superhydrophobic effect will optimally block droplets and aerosols, both from outside the mask and if the mask user is a Covid-19 survivor. Another effect of the graphene layer on the mask is that it creates photothermal activity that uses sunlight to catalyze reactions. When the cloth mask is coated with graphene, the data show that the photothermal process in the mask can reach 80 degrees, which can inactivate the virus.
“Based on the journal data we obtained, the spike protein in the SARS-CoV-2 virus is very sensitive to high temperatures, so that the cloth mask layer can produce a photothermal effect which will potentially inactivate it,” said Rifky.
The utilization of graphene from rice husks reveals a unique potential. Rice husk is a waste that is often generated from agricultural activities. “We know Indonesia is an agricultural country. Each rice harvest yields 20-30% of rice husk waste,” he said.
From the literature study, it was found that rice husks contain 30-40% carbon, the main substance of graphene. Unfortunately, at present rice husks are only used for animal feed. In fact, as a coating for cloth masks, graphene from rice husks can also be commercialized, as it has a high sale price at the global level.
Rifky and his team brought this literature research to the international ASEAN Innovative Science Environmental and Entrepreneur Fair, last month. As a result, the team won a gold medal and the “Best Innovation” award for the category of science and environmental innovation. A total of 505 participants from 20 countries participated in the virtual competition, initiated by the Indonesia Young Scientist Association in collaboration with other scientific institutions from various countries. (est)