The study of nano metal to enhance mold resistance ability of indoor building materials

Abstract

Extreme weather nowadays causes droughts and floods in many countries. The flood brings mold problems and deteriorates indoor air quality. It is difficult to remove mold on building materials. This study is aimed for improving mold resistance ability of selected building materials. Eight kinds of building materials were used for experiments. They are wooden flooring (WF), wooden flooring of green building material (GWF), calcium silicate board (CSB), calcium silicate board of green building material (GCSB), gypsum board (GB), gypsum board of green building material (GGB), mineral fiber ceiling (MFC), and mineral fiber ceiling of green building material (GMFC). Each building material was cut into 5 × 5 cm specimen, with Aspergillus, Penicillium fungi implanted. The humidity was controlled at 85%. Single kind or different combination of nano metal Ag, Cu, Zn and TiO2 was added in each specimen and cultured for 35 days to investigate enhancement of the ability for nano metals to resist mold. The results show the higher the concentration of nano metal, the stronger the anti-mold effect is. Besides, distinct building materials have different anti-mold properties. After TiO2 being impregnated at a concentration of 40 g/L, WF, MFC and GWF have better resistance to Aspergillus fungi, WF and GB have better resistance to Penicillium fungi. After nano silver being impregnated at a concentration of 0.03 g/L, MFC, GB, GMFC, and GGB have better resistance to Aspergillus fungi, WF, CSB, GMFC, GCSB have better resistance to Penicillium fungi. After nano copper being impregnated at a concentration of 0.05 to 0.10 g/L, WF has better resistance to Aspergillus fungi, WF, GB, GMFC, and GGB have better resistance to Penicillium fungi. After nano-zinc being impregnated at a concentration of 0.30 g/L, GGB has better resistance to Aspergillus fungi, WF and MFC have better resistance to Penicillium fungi. With appropriate nano metals being added, the anti-mold ability of building materials was found to be effectively improved and therefore improve indoor air quality.