Abstract: Cotton fibers, widely used as natural textile fibers, are favored for their skin-friendly, soft, and economical characteristics. However, they are susceptible to microbial contamination. With the frequent occurrence of global pandemics, the public's concern for hygiene and health issues has been increasing, and the demand for textiles with antibacterial properties has also risen accordingly.
Metal-organic frameworks (MOFs) represent a class of novel porous materials characterized by high porosity and large specific surface area, formed through coordination bonds between metal ions or clusters and organic ligands. Zeolitic imidazolate framework-L (ZIF-L), a subset of MOFs, is self-assembled from Zn2+ ions and 2-methylimidazole (2-MI) ligands. ZIF-L, through the release of Zn2+ ions, can disrupt bacterial cell membranes, interfere with the intracellular ionic environment balance, and damage bacterial proteins, thereby exerting antibacterial effects. The material itself possesses an intrinsic release system which slowly and persistently releases metal ions, achieving a long-term effective antibacterial effect. Compared with natural and organic antibacterial materials, ZIF-L's inorganic antibacterial properties offer advantages such as high-temperature resistance, strong bactericidal power, long-lasting antibacterial effect, and low bacterial resistance. Moreover, ZIF-L's unique blade-like structure, oriented like a "dagger", can grow vertically on the carrier, providing a physical antibacterial mechanism by the tip destroying attached microorganisms. Further hydrophobic treatment on the antibacterial cotton fabric can create a hydrophobic surface akin to the lotus leaf effect. Hydrophobic self-cleaning surfaces can repel water; water droplets roll away dirt and bacteria during the rolling process, achieving self-cleaning effects.
This article used a cotton fabric as the base material and prepared two-dimensional leaf-like nanosheet structure ZIF-L using 2-methyl imidazole (2-MI) and zinc chloride (ZnCl2) as raw materials, and loaded it onto the surface of cotton fabric (ZIF-L@cotton) through in-situ growth. Subsequently, the hydrophobicity of the cotton fabric was endowed by vapor deposition of methyltrimethoxysilane (MTMS). The surface morphology and structure of the fabric were characterized by instruments such as field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The hydrophilicity and hydrophobicity of the fabric was analyzed by contact angle, and the antibacterial performance of the fabric was evaluated by inhibition zone and antibacterial rate experiments, while the stability of the fabric's performance was tested through multiple washing cycles. Experimental results showed that as the content of 2-MI and reaction time increased, the size and density of ZIF-L increased accordingly. With a molar ratio of 2-MI to ZnCl2 of 7:1 and a reaction time of 3 hours, a ZIF-L@cotton fabric with better morphology was obtained. Both the ZIF-L@cotton fabric and the MTMS/ZIF-L@cotton fabric had good antibacterial effects on E. coli and S. aureus. The ZIF-L@cotton fabric maintained good hydrophilicity, while the MTMS/ZIF-L@cotton fabric showed satisfactory hydrophobicity and self-cleaning properties, and retained stable functional performance after multiple washing cycles. In summary, this study demonstrates that the ZIF-L@cotton fabric and the MTMS/ZIF-L@cotton fabric exhibit good properties and hold broad application prospects in the field of antibacterial textiles.

Key words: ZIF-L, in situ growth, cotton, antibacterial, MTMS, self-cleaning

摘要： 以2-甲基咪唑(2-MI)和氯化锌(ZnCl2)为原料，制备金属有机框架(MOF)中的二维叶状纳米片结构ZIF-L，并通过原位生长将其负载到棉织物表面(ZIF-L@棉)。接着利用气相沉积技术，采用甲基三甲氧基硅烷(MTMS)对ZIF-L@棉织物进行表面改性，赋予其自清洁功能。通过扫描电子显微镜、傅里叶变化红外光谱仪和X射线光电子能谱分析仪等对织物的表面形貌和结构进行表征，再通过测量接触角分析织物的亲疏水性，通过抑菌圈和抗菌率实验分析织物的抗菌性能。此外，对MTMS/ZIF-L@棉织物进行多次水洗测试，分析探究织物性能的稳定性。结果表明：随着2-MI含量和反应时间的增加，ZIF-L的尺寸和覆盖密度随之增加。当2-MI与ZnCl2的摩尔比为7∶1，反应时间为3 h，获得了具有较好形貌的ZIF-L@棉织物。ZIF-L@棉织物和MTMS/ZIF-L@棉织物对大肠杆菌和金黄色葡萄球菌均具有良好的抗菌效果。ZIF-L@棉织物保持了良好的亲水性，而MTMS/ZIF-L@棉织物则表现出较好的疏水性和自清洁性，且具有良好的功能稳定性，在抗菌纺织品领域显示出了广阔的应用前景。

关键词: 二维Zn基金属有机框架(ZIF-L), 原位生长, 棉织物, 抗菌, 甲基三甲氧基硅烷(MTMS), 自清洁