竹材表面ZnO的低温制备及其防霉性能研究

为改善竹材的防霉性能,采用低温水热法,以硝酸锌和六亚甲基四胺为原料,在竹材表面制备ZnO纳米晶层。通过扫描电镜观察了试样表面的微观形貌,并结合X射线能谱仪研究了试样表面的元素状态,还通过X射线衍射仪研究了试样的结晶形态,以及采用热失重检测仪分析了试样的热降解过程,最后测试了ZnO负载前后竹材的防霉性能。试验结果表明,低温水热法可以成功制备纤锌矿ZnO纳米晶体,并使其紧密负载在竹材表面。室内防霉试验结果表明,ZnO负载的竹材对黑曲霉和青霉具有明显的防护作用,但对木霉的防护作用不明显。室外防霉试验结果表明,与竹材素材相比,ZnO负载的竹材具有较好的防霉效果,可以使霉菌推迟2个月出现。
Bamboo is especially easy to discolor by mould fungi, which greatly limits the applications of bamboo. In order to improve the antifungal performance of bamboo, the ZnO nanostructures were deposited on the bamboo surface via a low-temperature hydrothermal method by using zinc nitrate(Zn(NO3)2)and hexamethylenetetramine(C6H12N4)as raw materials in this study. The morphology, chemical structure, and crystalline structure of the original and the ZnO-coated bamboo were characterized by using the scanning electron microscope(SEM), energy dispersive spectroscopy, X-ray diffraction(XRD)and thermogravimetric analysis. The XRD analysis confirmed that the as-prepared ZnO nanostructures on the bamboo surface were all wurtzite crystals. The results of SEM images showed that the bamboo sample surface was densely covered by ZnO nanostructures after the low hydrothermal process. The antifungal performance of ZnO-coated bamboo was also examined. Both the laboratory and the field antifungal experiments were conducted on the treated bamboo to evaluate the resistance against mould fungi. In laboratory tests, the mould fungi including Aspergillus niger, Penicillium citrinum and Trichoderma viride were chosen as the target fungi, and the results indicated that the ZnO-coated bamboo had a better resistance against A. niger and P. citrinum, but not good against T. viride. Among the tested mould fungi, T. viride was the most tolerant one. It was necessary to develop a new nanomaterial to protect the bamboo, which could resist all the tested mould fungi effectively. In the field tests, compared with the original bamboo, the ZnO-coated bamboo also presented more superior antifungal capability under natural conditions during the two-month period