Wen Junwei, Huang Shuting, Sun Yu, Chen Zhengjie, Wang Yixiang, Li Houbin, Liu Xinghai
School of Printing and Packaging, Wuhan University, Wuhan 430079, China.
Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, QC H39 3V9, Canada.
Materials (Basel). 2018 Nov 29;11(12):2410. doi: 10.3390/ma11122410.
Colorimetric oxygen indicators can be applied for non-destructive testing in packaging; especially in modified atmosphere packaging (MAP). In this paper; titanium dioxide (TiO₂) nanotube; which is used as a semiconductor photocatalyst in oxygen indicators; was synthesized via a microwave-assisted hydrothermal method. X-Ray Diffraction (XRD) was used to analyze its crystal form and Scanning Electron Microscope (SEM).to characterize its morphology. Its properties were studied using Brunauer-Emmett-Teller (BET), Diffuse Reflection Spectrum (DRS), and Bluebottle experiments. The results showed that the synthesized TiO₂ nanotube was a mixture of rutile and anatase; with a specific surface area of 190.35 m²/g; and a wide band gap of 3.34 eV. Given the satisfactory performance; the TiO₂-based oxygen indicator was prepared and combined with glycerol; methylene blue; and hydroxyethyl cellulose (HEC). The oxygen indicator demonstrated excellent photocatalytic performance and effectively avoided excitation by visible light. We studied the rheological properties; thixotropic properties; and wettability of the indicator. The results demonstrated the printability of the indicator solution; which was then printed in the polyethylene terephthalate (PET) film by screen printing and applied to MAP. The application results showed that the prepared oxygen indicator was able to provide visual support to judge whether the packaging was intact and the food was safe.
比色氧指示剂可用于包装中的无损检测；尤其是在气调包装（MAP）中。本文采用微波辅助水热法合成了用作氧指示剂中半导体光催化剂的二氧化钛（TiO₂）纳米管。利用X射线衍射（XRD）分析其晶体形态，并通过扫描电子显微镜（SEM）表征其形貌。采用布鲁诺尔-埃米特-泰勒（BET）法、漫反射光谱（DRS）法和蓝瓶子实验研究了其性能。结果表明，合成的TiO₂纳米管是金红石和锐钛矿的混合物，比表面积为190.35 m²/g，带隙为3.34 eV。鉴于其令人满意的性能，制备了基于TiO₂的氧指示剂，并将其与甘油、亚甲基蓝和羟乙基纤维素（HEC）混合。该氧指示剂表现出优异的光催化性能，并有效避免了可见光的激发。我们研究了该指示剂的流变性能、触变性能和润湿性。结果表明该指示剂溶液具有可印刷性，然后通过丝网印刷将其印刷在聚对苯二甲酸乙二酯（PET）薄膜上并应用于气调包装。应用结果表明，制备的氧指示剂能够为判断包装是否完好以及食品是否安全提供视觉支持。
