石墨烯–聚乙烯醇奈米复合材料之制程与机械性质

Fabrication and Mechanical Properties of Graphene/PVA Nano-Composites

摘要: 本文探讨石墨烯与聚乙烯醇混合之奈米复材机械性质，探讨重点主要分成两个部份，第一部份是石墨烯制备方式，使用Modified Hummer Method将石墨粉末改质成氧化石墨烯，再使用六亚甲基四胺将氧化石墨烯还原成石墨烯，称为还原氧化石墨。藉由拉曼、X光光电子能谱以及原子力显微镜检测分析结果，显示成功的制造出单层的氧化石墨烯及将氧化石墨烯还原为石墨烯。第二部份是探讨氧化石墨烯与还原石墨烯于聚乙烯醇之不同添加量对奈米复材机械性质之影响。应用微拉力试验机对石墨烯–聚乙烯醇奈米复材进行拉伸试验，可得应力–应变曲线与杨氏系数，显示氧化石墨烯添加量的增加，会使聚乙烯醇由延性材料改变成脆性材料，纯聚乙烯醇于拉伸试验所得之杨氏系数714.3 MPa，添加3%氧化石墨烯之聚乙烯醇复材杨氏系数高达11290.3 MPa，杨氏系数提高了16倍。聚乙烯醇的拉伸强度平均约15 MPa，添加3%氧化石墨烯之聚乙烯醇复材平均拉伸强度最高可提升到37MPa，添加还原石墨烯之聚乙烯醇复材，因内含石墨烯未能均匀分散，强度最高仅为27 MPa。

Abstract: In this study, mechanical properties of nanocomposite materials, graphene and Polyvinyl Alcohol (PVA) are investigated. In the first part, the fabrication procedure of synthesizing graphene is discussed. Basically, we use Modified Hummer Method to oxidize graphite powder into graphene oxide (GO), and reduce graphene oxide back to graphene, also known as reduced graphene oxide (RGO), using hexamethylenetetramine (HTMA). From the result of XPS, Raman and AFM analysis, we’ve successfully demonstrated that graphene oxide is reduced back to graphene. In the second part, the mechanical properties of composite materials were discussed. We can extract stress and strain curve and Young’s modulus from tensile test. From these results, we’ve concluded that the ductility of Polyvinyl Alcohol has been decreased and has turned into brittle material while in-corporating additional graphene. In comparison with Young’s Modulus of 714.3 MPa and the av-erage tensile strength of 15 MPa for pure Polyvinyl Alcohol, the Young’s modulus has increased to 11290.3 MPa (almost 16 times of pure Polyvinyl Alcohol) and the average tensile strength can achieve 37 MPa while incorporating additional 3% grapheme oxide in Polyvinyl Alcohol. However, the tensile strength merely achieves 27 MPa while incorporating excess reduced graphene oxide in Polyvinyl Alcohol as a result of non-dispersive clusters of graphene.