Ultrahigh Adsorption of Toxic Substances from Cigarette Smoke Using Nanocellulose-SiO₂ Hybrid Aerogels

A cellulose nanofiber-SiO2 hybrid aerogel cigarette (CSG) filter, which can be used for ultrahigh adsorption of toxic substances from cigarette smoke, was prepared based on the skeletal material of cellulose nanofibers (CNFs) with the help of a simple directional frozen technology. SEM and FTIR results confirmed the successful introduction of the SiO2 nanoparticles, and the application process of SiO2 nanoparticles did not influence the three-dimensional network structure of CSGs. Considering the practical application of the CSGs on the cigarette filter, the mechanical and thermal properties of the CSGs were investigated. The stress–strain and TG curves showed that the mechanical and thermal stability properties of the CSGs increased compared with the pure cellulose nanofiber aerogel without the introduction of SiO2 nanoparticles. The adsorption capacity of the CSG filter tips against toxic substances from cigarette smoke was systematically investigated. Compared with conventional cellulose acetate filter tips, the CSG filter tips performed well at adsorption of tar, TPM (total particulate matter), nicotine, and CO from cigarette smoke with removal efficiencies of 92.23, 90.25, 95.02, and 20.63%, respectively. Crucially, the preparation of CSGs needs no extra chemical agents, showing an eco-friendly process. These results suggest that CSGs display great potential working as an ideal candidate for mainstream smoke toxicant adsorption.