The Korea Research Foundation announced on the 8th that the research team of researcher Dongyoon Choi of Korea Institute of Industrial Technology and Professor Jaehee Jeong of Sejong University developed an antibacterial filter manufacturing technology that kills microorganisms in the air with indoor lighting.
Microorganisms such as viruses, bacteria, and fungi are floating in the air mixed with fine dust.
Existing antibacterial filter materials such as silver and copper oxide are operated in a way that can be sterilized only when microorganisms directly contact the material surface.
This method has a problem that the antibacterial persistence decreases due to fine dust accumulated over time.
By using a titanium dioxide photocatalyst that absorbs sunlight and generates active oxygen that can kill microorganisms from surrounding oxygen and water, sterilization is possible without the microorganisms touching the filter.
However, ultraviolet rays are difficult to use in indoor spaces such as homes and offices, and energy that can be obtained from sunlight is extremely low, so it is not practical.
Accordingly, methods for increasing the reaction efficiency to visible light have been proposed, but the synthesis process is complicated and manufacturing cost is high, making it difficult to apply to filters.
The research team produced an antibacterial filter with a simplified process of dyeing an organic dye that reacts to visible light on titanium dioxide nanoparticles on the hydrophobic (water-repelling property) surface.
It solves the water instability problem of organic dyes, which are vulnerable to droplets, and increases the efficiency of generating active oxygen.
In the experiment in which Staphylococcus aureus in the air collected by the filter produced by the research team was exposed to indoor lighting (2.9㎽ per ㎠) and sunlight (18~21㎽ per ㎠) for 4 hours and 1 hour, respectively, more than 99.9% It showed antibacterial performance.
For practical use, the research team explained that additional research is needed to solve the problem of nanoparticle stability and evaluate human safety according to the active oxygen concentration.
Senior Researcher Dongyoon Choi said, “We plan to continue research to solve the problem of shortening the lifespan due to photolysis of organic dyes, and to achieve excellent antimicrobial properties even at lower light levels.”
The results of this study were published in the cover paper of the international journal’Nano Letters’ on the 24th of last month.
