Effect of the Silica Nanoparticles on Pore Size Control of the Air Filter Made from Cellulose Nanofibers (CNFs)

CNF (Cellulose nanofiber) air filter incorporated with the inorganic nanoparticle (SiO2, silicon dioxide) was explored. Vacuum filtration process was applied to prepare the air filter and optimized through the analysis in morphology, appearance observation, and filtration time. The SiO2 nanoparticles were introduced to control the pore structure of the CNFs based filter. FT-IR (Fourier transform infrared spectroscopy) and EDS (Energy dispersive X-ray spectrometer) results showed that the SiO2 nanoparticles were effectively attached on the surface of CNFs. SEM (Scanning electron microscope) images showed that the inorganic nanoparticles formed the homogeneous pore structure in the CNF filter. Finally, the CNF air filter with SiO2 had a particle (PM2.5) removal efficiency of about 70%. Pore control of the aifilter by adding SiO2 improved PM2.5 removal performance of the air filter by approximately 20% compared to the CNF air filter without the inorganic nanoparticles. These results demonstrated that the introduction of the inorganic nanoparticles in an CNF filter preparation can be a good approach to enhance the filter performace and control their pore structure.