茶多酚/还原石墨烯纳米复合物增强羧甲基壳聚糖薄膜性能的研究

Research on the enhancement of carboxymethyl chitosan film with tea polyphenol/reduced graphene nanocomposites

目的 探究茶多酚还原氧化石墨烯(grapheneoxide,GO)的能力,进一步利用茶多酚/还原氧化石墨烯(reduced graphene oxide,RGO)改善羧甲基壳聚糖薄膜的综合性能。方法 首先利用茶多酚的还原性制备出茶多酚/RGO,通过X射线衍射仪(X-ray diffractometry,XRD)和傅里叶变换红外光谱仪(Fourier transform infrared spectrometer,FT-IR)表征验证。进一步以羧甲基壳聚糖为基材,甘油为塑化剂,通过流延法制备出一系列不同茶多酚/RGO含量的复合薄膜,测试其力学性能、阻隔性能、光学性能及热稳定性等,分析不同配比对复合薄膜性能的影响。结果 茶多酚和GO的质量比为2:1时,GO被还原的效果较好;与纯羧甲基壳聚糖膜相比,当茶多酚/RGO含量为2.0%时,复合膜的拉伸强度提高了96.9%;当茶多酚/RGO含量为1.0%时,水蒸气透过率最低,为7.0×10^(-13) [g·cm/(cm^(2)·s·Pa)];随着茶多酚/RGO的添加,复合薄膜能够阻挡50%以上的310 nm以下的紫外光透过,表现出具有良好的抗紫外性。结论 茶多酚/石墨烯纳米复合物作为增强剂,可以有效地改善羧甲基壳聚糖薄膜的综合性能,为进一步拓展其在食品包装领域的应用提供了新的思路。

Objective To explore the reducibility of tea polyphenol to graphene oxide (GO),and further improve the properties of carboxymethyl chitosan composite films by tea polyphenol/reduced graphene oxide (RGO).Methods Firstly,tea polyphenol/RGO was prepared with the reducibility of tea polyphenol.The nanocomposite was characterized by X-ray diffractometry (XRD) and Fourier transform infrared spectrometer (FT-IR).Further,with the carboxymethyl chitosan as base material and the glycerol as plasticizer,a series of carboxymethyl chitosan composite films were prepared by tape casting method with different content of tea polyphenol/RGO.The mechanical properties,barrier properties,optical properties and thermal stability were tested,the effects of different content of tea polyphenol/RGO on the properties of the composite films were analyzed.Results The reduction effect of GO was better,as the ratio of tea polyphenol to GO was 2:1.Compared with pure carboxymethyl chitosan film,the tensile strength of the composite film increased by 96.9%with 2.0%content of tea polyphenol/RGO.When the content of tea polyphenol/RGO was 1.0%,the water vapor transmittance was the lowest,which was 7.0×10^(-13)[g·cm/(cm^(2)·s·Pa)].With the addition of tea polyphenol/RGO,more than 50%ultraviolet light below 310 nm was blocked by the composite film,which showed good ultraviolet resistance.Conclusion Tea polyphenol/graphene nanocomposites can be used as the reinforcer to effectively improve the comprehensive properties of carboxymethyl chitosan films,which provides a new idea for further development for further expanding its application in the field of food packaging.