A research team at the National University of Singapore has developed an innovative nanofiber solution that creates thin, see-through air filters that can remove up to 90% of PM2.5 particles, and achieve high air flow of 2.5 times better than conventional air filters. This results in better breathability, and the particle filtration efficiency can be further enhanced, depending on the purpose and functionality of the air filter.

The air filters developed by assistant professor Tan Swee Ching and his Ph.D. student Sai Kishore Ravi, from the Department of Materials Science & Engineering, are also eco-friendly and easy to produce – by simply applying the nanofiber solution onto ordinary nonwoven mesh, and leave it to dry naturally. In addition, the eco-friendly air filters improve natural lighting and visibility, while blocking harmful ultraviolet (UV) rays.

Using phthalocyanine, a chemical compound commonly used in dyeing, the researchers modified organic molecules that could self-organize, similar to the stacking of building blocks, to form nanoparticles and subsequently, nanofibers. The nanofibers, which exist in the form of an organic solution, easily “cling” onto the nonwoven mesh when dispersed onto the material.
The developed air filters, using the novel nanofiber solution, are two times better in quality than commercial ones, and are suitable for applications on windows and doors to improve indoor air quality. The air filters also have promising applications in respirators.

“Air pollution poses serious health threats,” explains Tan, the lead researcher. “Therefore, there is a strong need for economical and effective technologies for air filtration. Currently, most nanofibers used in air filters are energy intensive to produce and require specialized equipment. Our team has developed a simple, quick and cost-effective way of producing high-quality air filters that effectively remove harmful particles and further improves indoor air quality by enhancing air ventilation and reducing harmful UV rays. In the long run, it may even be possible for a DIY (do-it-yourself) kit to be made available commercially for consumers to make air filters at home.” 

The research team has filed a patent for this novel invention, and is looking into adding more functionalities, such as anti-bacterial properties, into the air filters. The researchers also plan to work with industry partners to commercialize the technology.