Jablonski Joseph E, Yu Longjiao, Malik Sargun, Sharma Ashutosh, Bajaj Akhil, Balasubramaniam SuriyaPrakaash L, Bleher Reiner, Weiner Rebecca G, Duncan Timothy V
Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Bedford Park, Illinois 60501, United States.
Department of Food Science and Nutrition, Illinois Institute of Technology, Bedford Park, Illinois 60501, United States.
ACS Omega. 2019 Aug 7;4(8):13349-13359. doi: 10.1021/acsomega.9b01529. eCollection 2019 Aug 20.
Clay/polymer nanocomposites (CPNs) are polymers incorporating refined clay particles that are frequently functionalized with quaternary ammonium cations (QACs) as dispersion aids. There is interest in commercializing CPNs for food contact applications because they have improved strength and barrier properties, but there are few studies on the potential for QACs in CPNs to transfer to foods under conditions of intended use. In this study, we manufactured low-density poly(ethylene) (LDPE)-based CPNs and assessed whether QACs can migrate into several food simulants under accelerated storage conditions. QACs were found to migrate to a fatty food simulant (ethanol) at levels of ∼1.1 μg mg CPN mass after 10 days at 40 °C, constituting about 4% total migration (proportion of the initial QAC content in the CPN that migrated to the simulant). QAC migration into ethanol was ∼16× higher from LDPE containing approximately the same concentration of QACs but no clay, suggesting that most QACs in the CPN are tightly bound to clay particles and are immobile. Negligible QACs were found to migrate into aqueous, alcoholic, or acidic simulants from CPNs, and the amount of migrated QACs was also found to scale with the temperature and the initial clay concentration. The migration data were compared to a theoretical diffusion model, and it was found that the diffusion constant for QACs in the CPN was several orders of magnitude slower than predicted, which we attributed to the potential for QACs to migrate as dimers or other aggregates rather than as individual ions. Nevertheless, the use of the migration model resulted in a conservative estimate of the mass transfer of QAC from the CPN test specimens.
粘土/聚合物纳米复合材料（CPNs）是一种聚合物，其中掺入了经过精制的粘土颗粒，这些颗粒通常用季铵阳离子（QACs）进行功能化处理，作为分散助剂。人们对将CPNs商业化用于食品接触应用很感兴趣，因为它们具有改进的强度和阻隔性能，但关于CPNs中的QACs在预期使用条件下转移到食品中的可能性的研究很少。在本研究中，我们制造了基于低密度聚乙烯（LDPE）的CPNs，并评估了QACs在加速储存条件下是否会迁移到几种食品模拟物中。发现在40℃下放置10天后，QACs会以约1.1μg/mg CPN质量的水平迁移到脂肪类食品模拟物（乙醇）中，约占总迁移量的4%（CPN中初始QAC含量迁移到模拟物中的比例）。从含有大致相同浓度QACs但不含粘土的LDPE中，QACs向乙醇中的迁移量高出约16倍，这表明CPN中的大多数QACs与粘土颗粒紧密结合，无法移动。发现从CPNs中迁移到水性、酒精性或酸性模拟物中的QACs可以忽略不计，并且迁移的QACs量也与温度和初始粘土浓度成正比。将迁移数据与理论扩散模型进行比较，发现CPN中QACs的扩散常数比预测值慢几个数量级，我们将其归因于QACs可能以二聚体或其他聚集体形式迁移，而不是以单个离子形式迁移。尽管如此，使用迁移模型对CPN测试样品中QAC的传质进行了保守估计。
