Curled silica nanostructures formed on filter membranes for efficient bioaerosol and particulate matter removal

Due to environmental pollution from fine dust and the transmission of infectious diseases, there is a growing demand for high-performance membranes capable of effectively filtering these contaminants. This study develops a rough and curly nanostructure on existing smooth filter fibers using a catalyst droplet-based nanostructure-synthesis method to efficiently capture airborne particles and microorganisms. These curled silica nanostructures are beneficial for capturing aerosols while ensuring air permeability through the spaces between the curled structures. Computational analysis revealed that these curled nanostructures provided sufficient space for particle attachment while maintaining airflow channels. Our evaluations using aerosolized nanoparticles, microparticles, and bacteria demonstrated that the nanostructured filter outperformed the bare filter in terms of particle-capture efficiency. The medium-curled filter exhibited the highest quality factor with a balanced performance of minimal pressure loss and high capture efficiency. When exposed to aerosols of Staphylococcus aureus and Escherichia coli, the curled filter exhibited improved capture efficiencies of 73% and 92% without significant pressure loss, and the quality factor increased to 95.1% and 43.1%, respectively. Overall, the curled nanostructured filter showed considerable potential as an efficient barrier against airborne infectious microorganisms and fine particles. It can be economically viable and widely applicable in the filter market.