Novel mold-resistant building materials impregnated with thermally reduced nano-silver

Abstract

In this study, we evaluated the long-term antifungal effectiveness of 3 types of interior building materials (gypsum board [GB], cement board [CB], and softwood plywood [S-PW]) impregnated with thermally reduced silver nanoparticles supported by titanium dioxide (AgNPs/TiO ) under 95% relative humidity for 4 weeks. AgNPs/TiO was synthesized at 2 thermal reduction temperatures (TRTs, 120 and 200°C) with 2 different AgNP weight percentages (2 and 5 wt%). Four different silver-loading levels (SLLs, 0.025, 0.05, and 0.5 μg/cm and the critical concentration required to inhibit fungal growth on agar plates) and 3 fungal species (Aspergillus niger, Penicillium spinulosum, and Stachybotrys chartarum) were used in the experiments. Higher temperature reduced more ionic Ag to metallic Ag and increased the dispersion of Ag on TiO surface. The 200°C thermally reduced AgNPs/TiO demonstrated excellent antifungal efficiency: Mold growth was almost completely inhibited for 28 days at the low SLL of 0.5 μg/cm . Additionally, AgNPs/TiO exhibited higher antifungal activity on GB and CB than on S-PW. The stepwise regression results indicated that the TRT of AgNPs/TiO (β = -0.739 to -0.51), the SLL (β = -0.477 to -0.269), and the Ag level in the AgNPs (β = -0.379 to -0.136) were the major factors influencing antifungal activity and TRT might be the most significant one.

Understanding building-occupant-microbiome interactions toward healthy built environments: A review

“…Some studies suggest that high levels of copper in pipe materials inhibit Legionella survival and growth in indoor plumbing systems (van der Kooij et al, 2005;Proctor et al, 2017), while others found increased persistence of Legionella in biofilms formed on copper plumbing materials (Buse et al, 2014). A significant portion of indoor surfaces, including textiles, have incorporated metal nanoparticles to discourage fungal and bacterial growth (Chen et al, 2018;da Silva et al, 2019). Recently, the green wall and green roof concepts have also been introduced into buildings.…”

Nano-AgCu Alloy on Wood Surface for Mold Resistance

“…For example, applying nano-silver loaded TiO 2 (51.53 nm) to wood-based materials contributed excellent anti-mold effects to the surface against Aspergillus niger and Trichoderma viride growth, with protection efficiency of 93.33% and 96.67%, respectively [ 20 , 21 ]. Softwood plywood, impregnated with thermally reduced silver nanoparticles supported by titanium dioxide (AgNPs/TiO 2 ), demonstrated excellent antifungal effects and showed rare Aspergillus niger mold growth on the surface [ 22 ]. Nanoscale silver, copper and titanium dioxide particles (40–50 nm) directly brushed onto pine and beech wood surfaces, heavily inhibited the growth of Aspergillus niger [ 23 ].…”

Nanocomposite Building Materials in Modern Architectural Design

“…Combined with nanotechnology, many new materials can be developed, which are in line with today's architectural design concepts. The use of nanomaterials to shield ultraviolet rays can improve the antiaging yellowing performance of the wall, greatly improve the strength of plastic pipes, and increase the service life [6,7]. Domestic research has also begun to explore the development and application of nanomaterials and nanotechnology in building materials and found that nano-conforming building materials also have a good self-cleaning function, which is useful for antibacterial and antimildew coatings in buildings and some conductive materials.…”