Development of stiff, strong, yet tough composites by the addition of solvent exfoliated graphene to polyurethane
Development of stiff, strong, yet tough composites by the addition of solvent exfoliated graphene to polyurethane
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DOI：
10.1016/j.carbon.2010.07.008
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发表时间：
2010-11-01
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：
Khan, Umar;May, Peter;Coleman, Jonathan N.
我们已经制备了石墨烯分散体，由聚氨酯在四氢呋喃和二甲基甲酰胺中稳定。这些分散体可以滴铸以生产独立的复合薄膜。石墨烯的质量分数由分散石墨烯的浓度决定，可以在0%到90%之间可控地变化。拉曼光谱和氦离子显微镜显示，即使在55%的质量分数下，石墨烯在复合材料中也能很好地分散和剥离。添加石墨烯后，在3%应变下的杨氏模量和应力增加了100倍，当质量分数超过50% wt%时，杨氏模量和应力分别在1 GPa和25 MPa时达到饱和。虽然极限拉伸强度随石墨烯含量变化不大，但断裂应变和韧性随石墨烯含量的增加而显著降低。当石墨烯含量增加到90% wt%时，这两种性能都下降了1000倍。而在3%应变下，杨氏模量和应力随质量分数的增加速率大于塑性和韧性的下降速率。这使得制备具有高模量、低应变应力和极限抗拉强度以及相对较高的韧性和延展性的复合材料成为可能。这可能会产生坚硬、坚固和坚韧的新材料。(C) 2010 Elsevier Ltd.版权所有。
We have prepared graphene dispersions, stabilised by polyurethane in tetrahydrofuran and dimethylformamide. These dispersions can be drop-cast to produce free-standing composite films. The graphene mass fraction is determined by the concentration of dispersed graphene and can be controllably varied from 0% to 90%. Raman spectroscopy and helium ion microscopy show the graphene to be well-dispersed and well-exfoliated in the composites, even at mass fractions of 55%. On addition of graphene, the Young's modulus and stress at 3% strain increase by x100, saturating at 1 GPa and 25 MPa, respectively, for mass fractions above 50 wt%. While the ultimate tensile strength does not vary significantly with graphene content, the strain at break and toughness degrade heavily on graphene addition. Both these properties fall by x1000 as the graphene content is increased to 90 wt%. However, the rate of increase of Young's modulus and stress at 3% strain with mass fraction is greater than the rate of decrease of ductility and toughness. This makes it possible to prepare composites with high modulus, stress at low strain and ultimate tensile strength as well as relatively high toughness and ductility. This could lead to new materials that are stiff, strong and tough. (C) 2010 Elsevier Ltd. All rights reserved.