Ag NPs改性鱼鳞明胶-琼脂复合膜的制备及性能表征

利用鱼鳞明胶作为还原剂和稳定剂制备银纳米颗粒（silver nanoparticles, Ag NPs），研究Ag NPs添加量（0.04wt%-0.2wt%）对鱼鳞明胶-琼脂复合膜的理化性能和抗菌性能的影响。通过透射电子显微镜和X射线粉末衍射对合成的Ag NPs进行表征，结果表明制得Ag NPs为球形形貌，平均粒径为9.3 ?1.8 nm。随着Ag NPs添加量的增加，鱼鳞明胶-琼脂复合膜的色泽变黄渐深，透明度下降，对紫外和可见光的吸收增强，同时，复合膜的断裂延展性、水蒸气阻隔性能和耐水性能显著增强，而厚度和抗拉强度却无明显变化。FTIR和热重分析结果表明，Ag NPs与膜基质间存在化学相互作用，并在一定程度上改善了复合膜的热稳定性。抑菌环实验结果显示，复合膜可以在0.04wt%-0.2wt%较低的银浓度下实现良好的抗菌效果。研究结果将为鱼鳞明胶可降解抗菌包装材料的开发提供新思路。

Preparations and characterization of fish scale gelatin-agar composite films incorporated with silver nanoparticles

Fish scale gelatin, as a reducing agent and stabilizer, has been used to prepare silver nanoparticles (AgNPs) and fish scale gelatin/agar composite films with AgNPs loading (0.04-0.2%, dry weight). AgNPs were characterized by UV-Vis spectroscopy (UV-Vis), transmission microscopy (TEM), X-ray diffraction (XRD) to check the physicochemical properties. AgNPs were spherical and homogeneous with an average particle size of 9.3 nm. With the addition of AgNPs, the color of fish scale gelatin/agar composite films turned yellow, the transparency reduced, and the absorption of ultraviolet and visible light enhanced. Besides, the elongation at break, water-resistance and water vapor barrier properties of the films were significantly enhanced with the addition of AgNPs; however, the thickness and tensile strength had no change. FTIR and TG analyses showed that Ag NPs chemically interacted with fish scale gelatin and agar, and the thermal stability of the composite films was improved to some extent. Finally, the films incorporated with Ag NPs exhibited strong antibacterial activity against tested pathogens bacteria. Importantly, AgNPs and fish scale gelatin-agar composite films are compatible with the utility of AgNPs at a very low silver concentration in antibacterial packaging.