Ministry of Education Engineering Research Center of Starch & Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Ministry of Education Engineering Research Center of Starch & Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Carbohydr Polym. 2016 Dec 10;154:186-93. doi: 10.1016/j.carbpol.2016.08.006. Epub 2016 Aug 4.
To improve the water vapor resistance of starch-based films, Na-MMT (Na-montmorillonite) as nanofillers were fabricated into hydroxypropyl starch and the multi-scale structural changes (including intermolecular interaction, short-range conformation, long-range ordered structure and the aggregated structure of the film) were revealed. The elongation of the water vapor molecule pathway by tortuous path is generally recognized as the main reason for the improvement of water resistance. However this study observed the lowest water vapor permeability (WVP) was at the 3% Na-MMT/hydroxypropyl starch (HPS) ratio instead of 5% even nanofillers were partially exfoliated at both ratio. Except for the "tortuous path" caused by nanofillers, this observation proposed that the short-range conformation of HPS chains, long-range ordered structure and the aggregated structure likely influenced the water barrier property. The relationship between WVP and multi-scale structure of the film was investigated. The results suggested that a good balance of short-range conformationin the amorphous region, long-range ordered structure and the aggregated structure of the film was required for the improvement of water vapor barrier property.
为了提高淀粉基薄膜的水蒸气阻隔性能，将 Na-MMT（钠基蒙脱土）作为纳米填料加入到羟丙基淀粉中，并揭示了其多尺度结构变化（包括分子间相互作用、短程构象、长程有序结构和薄膜的聚集结构）。水蒸气分子通过曲折路径的延伸通常被认为是提高阻隔性能的主要原因。然而，本研究观察到，在 3% Na-MMT/羟丙基淀粉（HPS）比例下，而不是在 5%比例下，尽管纳米填料在这两种比例下都部分剥离，水蒸气透过率（WVP）最低。除了纳米填料引起的“曲折路径”外，这一观察结果表明，HPS 链的短程构象、长程有序结构和聚集结构可能会影响其对水的阻隔性能。本文还研究了 WVP 与薄膜多尺度结构之间的关系。结果表明，改善水蒸气阻隔性能需要在无定形区中具有良好的短程构象平衡、长程有序结构和薄膜的聚集结构。
