Several students from the Universitas Sumatera Utara (USU) who were members of the Nanofilter Mask Team in 2021 have carried out research for mask filters using nanofiber from banana stem waste. The work of the Exact Research Student Creativity Program (PKM) entitled "Effectivity of Cellulose Acetate Nanofibers from Banana Midrib Waste (Musa paradisiaca L.) as an Antibacterial Filter on Masks" was presented at the 34th Pimnas event in October 2021. Their research was also exhibited in the form of a poster at the PIMNAS. The potential for commercial use in the medical field is quite large, but for further product development, funding issues are still an obstacle and require substantial financial support.

The Nanofilter Mask team consisted of Sylvia Romalia Simanungkalit, Putri Amelia Sihotang, Shofi Tasa Al-Khairi and Dzul Hadi Sahputra from the Faculty of Mathematics and Natural Sciences (MIPA) S-1 Chemistry, and Brian Christopher from the Faculty of Dentistry.

Sylvia Romalia Simanungkalit as the team leader said the work was made based on the Covid-19 pandemic situation, where masks are the main need for the community for self-protection. Moreover, there are many masks circulating in the market that do not meet the standards of the World Health Organization (WHO).

"Seeing that masks are highly crucial and and needed, so we decided to make a mask filter using nanofiber," she said. "We saw the method of manufacture from review of journals and it turns out that it can be done in the laboratory. The filter that we made is anti-bacterial. The advantage of this filter is to increase the effectiveness of the mask filter because its size is smaller than the size of bacteria. Nanofiber filters bacteria that will enter," Sylvia explained.

Banana midrib was chosen as a source of nanofiber because it contains anti-bacterial compounds in the form of flavonoids, alkaloids, phenols and saponias. The cellulose content contained in the banana midrib is also quite large, which is about 63 percent. Banana stems were also chosen because they are very easy to obtain, especially the Barangan banana which is an endemic plant in North Sumatra. However, the products resulting from the research are still very rare that use banana midrib. Sylvia and the team have done screening, "contact angle" test and product application. It is hoped that this mask filter product can be downstreamed and benefit the community.

According to Sylvia, the first time creating a PKM team was not meant to participate in PIMNAS, because it was the first time they had tried it. Then they started doing research and looking for assistant lecturers. In early February 2021 they received a supervisor from F-MIPA, Muhammad Zulham Efendi Sinaga S.Si., M.Sc. Under the guidance of the lecturer, they began to develop proposals and determine the title.

“Making masks is difficult, because there must be 3 layers. We decided to make the middle layer made from banana midrib, then processed into alphacellulose. Then it is synthesized into cellulose acetate, then etrospined into nanofibers. After the proposal was made, then an announcement was made about the funding in July 2021. It turned out that we passed the funding from Dikti and started practicum for three months,” Sylvia mentioned.

After the practicum, they started looking for etrospining tools. Found the tool in Bandung. Indeed, very few have the tool because it is very expensive. The processing results are then sent to Bandung so that the nanofiber is obtained.

“The nanofiber in sheet form was sent to us for further testing. After that we made another paper and progress report, then presented again. His name is PKP 2 which is the determination to enter Pimnas. Finally, he passed again to the Pimnas stage and was guided from USU to face the judging. We are doing presentation exercises and making posters, as well as the attitudes that must be shown when making presentations, so that we hope to get good results,” Dzul Hadi Sahputra mentioned.

Zulham as the supervising lecturer explained that usually banana midribs are discarded by the community because they are considered to have no benefits. However, it turned out to be very high in cellulose. “By choosing this banana midrib waste, that's where the waste utilization process takes place. Yesterday's initial condition was checked for antimicrobials, against two bacteria, namely staphylococcus and e-coli. It turned out that the positive results could inhibit the bacteria. Then it was applied as a mask, which initially only made nanofilters. But because Pimnas must be applied in the form of a product, then we turn it into a filter mask, for this type of cloth mask. Cloth masks were chosen because they are the easiest to make. Make two layers and then insert the filter in the middle," he explained.

Talking about its effectiveness, Zulham emphasized that the filter from the banana midrib has nano-sized pores, so that the dirt in the air can be filtered out. Even droplets from Covid-19, that is about 0.5 micro in size will be able to be stuck outside the mask. They will further develop this filter, by continuing clinical, pre-clinical and efficacy trials for breathing difficulties while wearing it. The mask used has three layers. According to Zulham, many ordinary people are currently wearing cloth masks that can be washed repeatedly. They are worried that the level of sterilization and its effectiveness will not be maximized. With a mask that uses a nanofilter with anti-bacterial effectiveness, it is not only useful for preventing bacteria from entering, but also preventing bacteria from growing.

“Furthermore, the filtration power is really good like a medical mask. It will be developed for use by paramedics and the public. One of the biggest obstacles is the lack of available etrospining tools. USU itself only has one etrospining device, which so far only exists in the post-chemistry laboratory. Etrospining is useful for making nanofilter membranes. We send samples, after the membrane sheet is finished, it will be sent back. The costs incurred for production are still on a laboratory scale, so the price cannot be reduced on an industrial scale," Zulham said.

He further added that DIKTI funding for student creativity was Rp. 8.5 million which was used for the purposes of making products, posters and others. Product development certainly requires financial support.

“The funding from DIKTI is limited, so it can only be completed until that stage. For further product development of course requires a special allocation of funds. There are also funds that come from the guidance of students and lecturers. Funds from lecturer research, can be DRPM, can be talents, able to be shared with students. What is currently not the lecturer's research, but made by the students themselves, their own ideas. With that raw idea, they came to the assistant lecturer, and then they were directed. Asked what should be tested and the literature should be searched again. Students usually don't know what to test. The idea is indeed their own, but the proposal must be refined, the procedure must be appropriate. That is the task of the assistant lecturer,” Zulham mentioned. (RJ-©ULC)