Department of Polymer Science and Engineering, Inha University, Incheon 22212, South Korea.
Nanoscale. 2018 Jan 25;10(4):2025-2033. doi: 10.1039/c7nr07098e.
Polymeric nanocomposites with graphene-based nanocarbons (GNCs) have been extensively studied with emphasis on the percolation of nanofillers toward electrical, rheological, and mechanical reinforcement. In this study, we report an unusual indirect reinforcing phenomenon of highly defective GNCs dispersed in the poly(vinyl chloride) (PVC) matrix via densification of the polymer packing originating from nanoscale confinement. Herein, chemically reduced graphene oxide nanoribbons (C-rGONRs) are employed as a nanofiller. The inclusion of defective and oxygen-functionalized C-rGONRs resulted in a dramatic densification of the PVC host with extremely low C-rGONR loading, largely exceeding the theoretical calculation from a rule of mixture. Along with the densification, the glass transition temperature of PVC also increased by 28.6 °C at 0.1 wt% filler loading. Remarkably, the oxygen barrier property and mechanical toughness under tension for the PVC/C-rGONR nanocomposite were the maximum when the greatest densification occurred. The structure-property relationship of the nanocomposites has been discussed with an emphasis on the nanoscale confinement phenomenon.
具有基于石墨烯的纳米碳（GNC）的聚合物纳米复合材料已经得到了广泛的研究，重点是纳米填料的渗滤对电、流变和机械增强的影响。在本研究中，我们通过源自纳米尺度限制的聚合物堆积的致密化，报告了高度缺陷的 GNC 在聚氯乙烯（PVC）基质中分散的异常间接增强现象。在这里，化学还原氧化石墨烯纳米带（C-rGONRs）被用作纳米填料。含有缺陷和含氧官能化的 C-rGONRs 的存在导致 PVC 主链的急剧致密化，即使在极低的 C-rGONR 负载下，也大大超过了混合物规则的理论计算。随着致密化，在 0.1wt%填充剂负载下，PVC 的玻璃化转变温度也增加了 28.6°C。值得注意的是，当发生最大致密化时，PVC/C-rGONR 纳米复合材料的氧气阻隔性能和拉伸韧性达到最大值。已经讨论了纳米复合材料的结构-性能关系，重点是纳米尺度限制现象。
