纳米金属/金属氧化物-聚烯烃食品包装膜中纳米成分迁移的扩散系数估算

Estimation of Diffusion Coefficients of Nano-Components Migration from Nano-Metal/Metal Oxide-Polyolefin Food Packaging Film

为探讨Fick第二定律是否符合聚烯烃食品包装膜中纳米成分向食品模拟物的迁移规律,根据已有实验数据,基于Crank模型进行拟合,估算纳米金属/金属氧化物-聚烯烃食品包装膜中纳米成分的扩散系数,并分析温度、聚烯烃、纳米成分和食品模拟物对扩散系数的影响。结果表明:纳米成分向食品模拟物的迁移符合Fick第二定律。温度升高促进纳米成分的迁移,且温度与纳米成分扩散系数的关系符合Arrhenius公式。不同聚烯烃结构对扩散系数的影响不同;聚丙烯3种结构中,纳米铜和纳米氧化锌在均聚共聚聚丙烯中的扩散系数最大。不同纳米成分质量分数对其扩散系数的影响不同。纳米成分与食品模拟物、聚烯烃之间的溶解度差异也会影响其向食品模拟物迁移。

In order to investigate whether the migration of nano-components from polyolefin food packaging films into food simulants obeys Fick’s second law, the available experimental data were fitted to the Crank model to estimate the diffusion coefficients of nano-components migration from nano-metal/metal oxide-polyolefin food packaging films. The effects of temperature, polyolefin, nano-components and food simulants on the diffusion coefficient were analyzed. The results showed that the migration of nano-components into food simulants was consistent with Fick’s second law. The increase in temperature promoted the migration of nano-components, and the relationship between the diffusion coefficients and temperature was in accordance with the Arrhenius model. The structures of polyolefin had different effects on the diffusion coefficients;among three structures of polypropylene, nano-copper and nano-zinc oxide had the largest diffusion coefficient in isotactic polypropylene. Different concentrations of nano-components had different effects on their diffusion coefficients. The solubility differences between nano-components and food simulants and polyolefins affected the migration of nano-components into food simulants.