Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, BeiHang University, Beijing, China.
Nanoscale. 2013 Jul 21;5(14):6356-62. doi: 10.1039/c3nr00801k. Epub 2013 May 15.
Montmorillonite/poly(vinyl alcohol) (MMT/PVA) nanocomposites spanning the complete range of MMT content (0-100 wt%) are prepared by simple evaporation-induced assembly. Effects of MMT content on the structure and mechanical properties of nanocomposites are systematically investigated and exhibit two important transitions at MMT contents of 30 wt% and 70 wt%. In the range of 0-30 wt%, the nanocomposites show a random structure. With the content of PVA increasing, the mechanical properties of the resultant nanocomposites were dramatically enhanced and were higher than that by prediction according to the conventional composite model. In the range of 30-70 wt%, the nanocomposites show a nacre-like layered structure with alternating MMT platelets and PVA layers, and all PVA is completely restricted by MMT platelets. The mechanical properties of nanocomposites were further improved by increasing the content of MMT, and reached the maximum value at the MMT content of 70 wt%. The 70 wt% MMT/PVA nanocomposite has a tensile strength of 219 ± 19 MPa, which is 5.5 times higher than that of a pure PVA film and surpasses nacre and reported biomimetic layered clay/PVA composites. When the MMT content is higher than 70 wt%, the layered structure is transformed to tactoids, which deteriorate mechanical properties. These results offer comprehensive understanding for developing high-performance biomimetic layered nanocomposite materials with high nanofiller loading.
通过简单的蒸发诱导组装，制备了蒙脱土/聚乙烯醇（MMT/PVA）纳米复合材料，其蒙脱土含量涵盖了整个范围（0-100wt%）。系统研究了蒙脱土含量对纳米复合材料结构和力学性能的影响，在蒙脱土含量为 30wt%和 70wt%时表现出两个重要转变。在 0-30wt%范围内，纳米复合材料呈现无规结构。随着 PVA 含量的增加，所得纳米复合材料的力学性能得到显著提高，并且高于根据传统复合材料模型的预测值。在 30-70wt%范围内，纳米复合材料呈现出具有交替的 MMT 层板和 PVA 层的珍珠层状层状结构，所有 PVA 都被 MMT 层板完全限制。通过增加蒙脱土的含量，纳米复合材料的力学性能进一步提高，并在蒙脱土含量为 70wt%时达到最大值。70wt%MMT/PVA 纳米复合材料的拉伸强度为 219±19MPa，是纯 PVA 薄膜的 5.5 倍，超过了珍珠层和报道的仿生层状粘土/PVA 复合材料。当蒙脱土含量高于 70wt%时，层状结构转变为球晶，从而降低了力学性能。这些结果为开发具有高纳米填料负载量的高性能仿生层状纳米复合材料提供了全面的认识。
