Improving the mechanical properties of graphene oxide based materials by covalent attachment of polymer chains
Improving the mechanical properties of graphene oxide based materials by covalent attachment of polymer chains
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DOI：
10.1016/j.carbon.2012.09.046
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发表时间：
2013-02-01
期刊：
影响因子：
10.9
通讯作者：
Coleman, Jonathan N.
中科院分区：
文献类型：
--
作者：
Cano, Manuela;Khan, Umar;Coleman, Jonathan N.
我们报告了用聚乙烯醇 (PVA) 对氧化石墨烯 (GO) 进行改性，从而改善了 GO 基材料的机械性能。首先，通过 GO 上的羧基与 PVA 的羟基酯化，将 GO 与 PVA 共价官能化，得到官能化的 f-(PVA)GO。这是针对六种不同分子量的 PVA 进行的。这种功能化的氧化石墨烯可以通过真空过滤形成纸状材料。与用 GO 或 GO 和 PVA 的简单混合物制备的纸张相比，由 f-(PVA)GO 制备的纸张机械性能显着提高。分子量在 50 至 150 kg/mol 之间的 PVA 官能团实现了最佳性能。相对于纯 GO 纸，杨氏模量提高了 60%，拉伸强度提高了 400%。机械性能的改善归因于共价键合的 PVA 增强了薄片间的应力传递。其次，功能化的 f-(PVA)GO 用作 PVA 基复合材料中的填料。预选方法的应用允许仅使用最大的官能化 f-(PVA)GO 薄片。这产生了显着增强的 PVA-f-(PVA)GO 复合材料。当 f-(PVA)GO 含量低于 0.3 vol.% 时，相对于纯聚合物，模量和强度均增加了 40%。 (C) 2012 Elsevier Ltd. 保留所有权利。
We report on the modification of graphene oxide (GO) with poly(vinyl alcohol) (PVA) leading to the mechanical improvement of GO based materials. First, GO was covalently functionalised with PVA by esterification of carboxylic groups on GO with hydroxyl groups of PVA resulting in functionalised f-(PVA)GO. This was carried out for PVA of six different molecular weights. This functionalised graphene oxide could be formed into a paper-like material by vacuum filtration. Papers prepared from f-(PVA)GO showed significant increases in mechanical properties compared to those prepared with GO or with simple mixtures of GO and PVA. The best performance was achieved for PVA functional groups with molecular weights between 50 and 150 kg/mol. Improvements in Young's moduli of 60% and tensile strength of 400% were observed relative to GO-only paper. The improved mechanical properties are attributed to enhanced inter-flake stress transfer due to the covalently bonded PVA. Second, functionalised f-(PVA)GO was used as filler in PVA-based composites. The application of a pre-selection method allowed the use of only the largest functionalised f-(PVA)GO flakes. This resulted in substantially reinforced PVA-f-(PVA)GO composites. Both modulus and strength increased by 40% relative to the pure polymer for f-(PVA)GO loadings below 0.3 vol.%. (C) 2012 Elsevier Ltd. All rights reserved.