Simultaneous Enhancement of Mildew Resistance and Dimensional Stability of Bamboo with a Facile One-Step In Situ Growth of ZnO/TA/Ag Composites

Bamboo is a renewable and fast-growing biomass resource with limited utilization and service life owing to its susceptibility to mold. Conventional nano-modification methods, particularly two-step approaches, are limited by weak interfacial bonding between nanoparticles and the bamboo substrate, complex processing, and an inability to simultaneously enhance antimildew performance and dimensional stability. To address these limitations, we developed a one-step hydrothermal method involving the use of tannic acid (TA) for in situ fabrication of ZnO/TA/Ag composite particles on bamboo surfaces. Process parameters were optimized to 100 °C, 10 h, and a zinc acetate-to-tannic acid molar ratio of 20:1. The modified bamboo was characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, and thermogravimetric analysis. We demonstrated that ZnO/TA/Ag composite particles were successfully loaded onto the bamboo surface, thus improving the all-around performance of the bamboo simultaneously. Antimildew activity against Aspergillus niger and Penicillium citrinum increased from grade 4 in untreated bamboo to grades 1 and 0, respectively; water absorption decreased by 52.85%, and anti-swelling efficiency reached 30.41%, indicating improved mold resistance and dimensional stability. Thus, our technique could serve as a green and efficient one-step in situ modification strategy for high-performance functionalization of bamboo, making it suitable for applications in humid outdoor and indoor environments.