Uysal Unalan Ilke, Boyacı Derya, Ghaani Masoud, Trabattoni Silvia, Farris Stefano
DeFENS, Department of Food, Environmental and Nutritional Sciences-Packaging Division, University of Milan, via Celoria 2-20133 Milan, Italy.
Department of Food Engineering, Faculty of Engineering, İzmir University of Economics, İzmir 35330, Turkey.
Nanomaterials (Basel). 2016 Dec 21;6(12):244. doi: 10.3390/nano6120244.
In this work, we present the development of bionanocomposite coatings on poly(ethylene terephthalate) (PET) with outstanding oxygen barrier properties. Pullulan and graphene oxide (GO) were used as main polymer phase and nanobuilding block (NBB), respectively. The oxygen barrier performance was investigated at different filler volume fractions (ϕ) and as a function of different relative humidity (RH) values. Noticeably, the impermeable nature of GO was reflected under dry conditions, in which an oxygen transmission rate (, mL·m·24 h) value below the detection limit of the instrument (0.01 mL·m·24 h) was recorded, even for ϕ as low as 0.0004. A dramatic increase of the values occurred in humid conditions, such that the barrier performance was totally lost at 90% RH (the of coated PET films was equal to the of bare PET films). Modelling of the experimental data by Cussler's model suggested that the spatial ordering of GO sheets within the main pullulan phase was perturbed because of RH fluctuations. In spite of the presence of the filler, all the formulations allowed the obtainment of final materials with haze values below 3%, the only exception being the formulation with the highest loading of GO (ϕ ≈ 0.03). The mechanisms underlying the experimental observations are discussed.
在这项工作中，我们展示了在聚对苯二甲酸乙二酯（PET）上开发具有出色氧气阻隔性能的生物纳米复合涂层。分别使用普鲁兰多糖和氧化石墨烯（GO）作为主要聚合物相和纳米构建块（NBB）。研究了在不同填料体积分数（ϕ）下以及作为不同相对湿度（RH）值的函数时的氧气阻隔性能。值得注意的是，GO的不渗透性质在干燥条件下得以体现，即使对于低至0.0004的ϕ，记录到的氧气透过率（，mL·m·24 h）值也低于仪器的检测限（0.01 mL·m·24 h）。在潮湿条件下，值急剧增加，以至于在90%相对湿度下阻隔性能完全丧失（涂覆PET薄膜的等于未涂覆PET薄膜的）。用库斯勒模型对实验数据进行建模表明，由于相对湿度的波动，主要普鲁兰多糖相内GO片层的空间排列受到干扰。尽管存在填料，但所有配方都能得到雾度值低于3%的最终材料，唯一的例外是GO负载量最高（ϕ≈0.03）的配方。讨论了实验观察结果背后的机制。
