Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, U.K.
ACS Appl Mater Interfaces. 2020 Mar 4;12(9):10973-10982. doi: 10.1021/acsami.9b21986. Epub 2020 Feb 20.
We report a method to rationally control the aspect ratio of layered double hydroxide for use as a barrier coating for food packaging films. The reconstruction of a MgAl-layered double oxide (LDO) in concentrated aqueous glycine solutions produces dispersions of MgAl-LDH nanosheets. The nanosheet thickness decreases and diameter increases with increasing reconstruction time from 16 to 96 h. We observe a limiting nanosheet aspect ratio of ca. 336 ± 170. These MgAl-LDH nanosheets can be dispersed in PVA to give a water-based dispersion that can be used to coat flexible polymeric films. Oxygen transmission rate (OTR) of a PET film decreases when the thickness of the dried coated layer increases, an OTR of <0.005 mL·m·day is observed for a coating with thickness of 1175 ± 101 nm.
我们报告了一种合理控制层状双氢氧化物纵横比的方法，将其用作食品包装薄膜的阻隔涂层。在浓水合甘氨酸溶液中重构 MgAl-层状双氧化物 (LDO) 会产生 MgAl-LDH 纳米片的分散体。随着重构时间从 16 小时增加到 96 小时，纳米片的厚度减小，直径增大。我们观察到纳米片的纵横比约为 336 ± 170。这些 MgAl-LDH 纳米片可以分散在 PVA 中，得到一种水性分散体，可用于涂覆柔性聚合物薄膜。当干燥涂层的厚度增加时，PET 薄膜的氧气透过率（OTR）降低，厚度为 1175 ± 101nm 的涂层的 OTR 低于<0.005mL·m·day。
