Fabrication and characterization of eco-friendly functional wallpaper using nonmetallic minerals

The effects of amounts and particle size of nonmetallic minerals on the rheological behavior of the slurry and microstructure evolution of an eco-friendly functional wallpaper were investigated to optimize preparation parameters. Mixed binder system was used to prepare the wallpaper. Nonmetallic minerals such as TiO₂, CaCO₃, illite, pearl, and small amounts of graphite were mixed with the binder and then ball milled for 12 h. The particle size of the starting materials was controlled by the milling process, showing a significant reduction in particle size. Mixed slurries coated on base paper (substrate) were dried and pressed at 150 °C, forming seven layers. The reduced particle size increases the amounts of the nonmetallic minerals in the slurry, which causes an increase in viscosity and inhibits powder sedimentation. Despite the increase in the amounts of nonmetallic minerals, the nonmetallic minerals are homogeneously dispersed, as confirmed by microstructure and EDS mapping. The nonmetallic minerals provide the wallpaper with eco-friendly functions such as unit-infrared emission and antifungal ability, and improve the deodorization ratio and decrease the emission ratio of TVOC and HCHO compared with conventional wallpaper.