改性纳米SiO_2微球的制备及其在果蔬保鲜中的应用

Preparation of Modified Nano-SiO_2 Microspheres and Its Application in FreshKeeping of Fruits and Vegetables

采用溶胶-凝胶法制备纳米SiO_2微球并对其接枝改性,与壳聚糖/淀粉溶液复合后应用于圣女果保鲜包装中。通过扫描电镜、红外光谱、粒径分析等表征,考察纳米SiO_2成球工艺参数和接枝改性效果;并研究了添加不同质量分数的改性纳米SiO_2微球对壳聚糖/淀粉/纳米SiO_2复合膜溶液保鲜效果的影响。结果表明:添加5 m L浓氨水、2.8 m L正硅酸四乙酯、40 m L乙醇并通过缓慢滴加的方式制备得到的微球粒径均一、分散性好;经硅烷偶联剂KH550接枝改性后的纳米SiO_2微球,能够改善复合膜的多项性能;当添加质量分数为3%的改性纳米SiO_2微球时,壳聚糖/淀粉/纳米SiO_2复合膜的保鲜效果较好。

Nano-SiO2 microspheres were prepared by sol-gel method and grafted with silane coupling agent KH550, then composited with chitosan/starch solution and applied in fresh-keeping packaging of cherry tomatoes. Scanning electron microscopy, infrared spectroscopy, particle size analysis were used to characterize the optimum technological paramentres and grafting effect of nano-silica microspheres. The preservation effect of chitosan/starch solution with the different mass fraction of nano-silica microspheres was analyzed. The results showed that： the uniform and monodisperse microspheres were prepared by adding 5 m L ammonia,2.8 m L tetraethyl orthosilicate,40 m L ethanol and slow droipping method;the nano-SiO2 microspheres modified by silane coupling agent KH550 could improve the performance of composite membrane; when the content of modified nano-SiO2 microspheres in chitosan/starch composite film was 3%, the fresh-keeping effect was better.