Pang Yunsong, Yang Junlong, Curtis Tyler E, Luo Shirui, Huang Dezhao, Feng Zhe, Morales-Ferreiro Jorge O, Sapkota Pitambar, Lei Fan, Zhang Jianming, Zhang Qinnan, Lee Eungkyu, Huang Yajiang, Guo Ruilan, Ptasinska Sylwia, Roeder Ryan K, Luo Tengfei
Department of Aerospace and Mechanical Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States.
Department of Materials Science and Engineering , Southern University of Science and Technology , Shenzhen 518055 , P. R. China.
ACS Nano. 2019 Feb 26;13(2):1097-1106. doi: 10.1021/acsnano.8b04734. Epub 2019 Jan 11.
Polymers with superior mechanical properties are desirable in many applications. In this work, polyethylene (PE) films reinforced with exfoliated thermally reduced graphene oxide (TrGO) fabricated using a roll-to-roll hot-drawing process are shown to have outstanding mechanical properties. The specific ultimate tensile strength and Young's modulus of PE/TrGO films increased monotonically with the drawing ratio and TrGO filler fraction, reaching up to 3.2 ± 0.5 and 109.3 ± 12.7 GPa, respectively, with a drawing ratio of 60× and a very low TrGO weight fraction of 1%. These values represent by far the highest reported to date for a polymer/graphene composite. Experimental characterizations indicate that as the polymer films are drawn, TrGO fillers are exfoliated, which is further confirmed by molecular dynamics (MD) simulations. Exfoliation increases the specific area of the TrGO fillers in contact with the PE matrix molecules. Molecular dynamics simulations show that the PE-TrGO interaction is stronger than the PE-PE intermolecular van der Waals interaction, which enhances load transfer from PE to TrGO and leverages the ultrahigh mechanical properties of TrGO.
具有优异机械性能的聚合物在许多应用中都很受欢迎。在这项工作中，使用卷对卷热拉伸工艺制备的、用剥离的热还原氧化石墨烯（TrGO）增强的聚乙烯（PE）薄膜显示出优异的机械性能。PE/TrGO薄膜的比极限拉伸强度和杨氏模量随拉伸比和TrGO填料分数单调增加，在拉伸比为60倍且TrGO重量分数非常低至1%时，分别达到3.2±0.5和109.3±12.7 GPa。这些值是迄今为止聚合物/石墨烯复合材料报道的最高值。实验表征表明，随着聚合物薄膜的拉伸，TrGO填料会被剥离，分子动力学（MD）模拟进一步证实了这一点。剥离增加了与PE基体分子接触的TrGO填料的比表面积。分子动力学模拟表明，PE-TrGO相互作用强于PE-PE分子间范德华相互作用，这增强了从PE到TrGO的载荷传递，并利用了TrGO的超高机械性能。
