Mold-resistant bamboo scrimber. Part 2: fabrication of chitosan-Cu-acrylamide treated bamboo scrimber

Bamboo scrimber has emerged as a fundamental material in outdoor flooring applications; however, its widespread adoption remains constrained by susceptibility to mold infestation. Part 1, which demonstrated the anti-mold property of chitosan-Cu-acrylamide (CAM), systematically investigated the anti-leachability and anti-mold mechanisms of CAM-treated bamboo scrimber. In this study (Part 2), chitosan-Cu-acrylamide synthesized from chitosan, copper, and acrylamide was used to prepare bamboo scrimber through two and one-step methods. The anti-mold properties of bamboo scrimber after leaching against Aspergillus niger (AN), Trichoderma viride (TV), and Penicillium citrinum (PC) were measured. Scanning electron microscopy (SEM) and pH analyses were employed to characterize the microstructural modifications and changes in the chemical environment. The results revealed exceptional retention of mold resistance post-leaching, with mass losses of 2.9% and 6.0% observed for the one and two-step CAM treatment methods, respectively. Notably, the treated bamboo scrimber maintained 100% preventive efficacy against all three types of molds. The SEM results indicated that the morphology of the starch particles within the cells was altered and covered by CAM. The pH analysis indicated a significant microenvironmental shift from acidic (pH 5.6) to neutral (pH 7.3) in the treated bamboo bundles. Results show that CAM treatment enhances the mold resistance of bamboo by reducing nutrients and modifying the chemical environment. The CAM treatment has great potential for enhancing the mold resistance of bamboo scrimbers.