石墨烯碳材料1.ppt

* Chapter 10 Graphene-based Nanocomposites 10.1 Introduction of composites 10.2 Introduction of graphene-polymer nanocomposites 10.3 Processing of graphene-polymer nanocomposites 10.4 Mechanical properties of graphene-polymer nanocomposites 10.1 Introduction of composites Definition: A composites is a material having two or more distinct constituents or phases, and have to satisfy the following criteria: 1. Both constituents have to present in reasonable proportions, say greater than 5%; 2. The constituents phases have different properties, and hence the composite properties are noticeably different from the properties of the constituents; 3. A man-made composite is usually produced by intimately mixing and combining the constituents by various means. Nanocomposites: Composites contain two or more nano-sized fillers. (Nano-structural composites) 10.1.1 Category of fibers and matrix for composites Fibers: Natural fibers Synthetic organic fibers Aramid fiber Polyethylene fiber Synthetic inorganic fibers Glass fibers Alumina fibers Boron fibers Carbon fibers Si C fibers Whiskers(SiC is available in the form of whiskers, i.e., small single crystals):A few tens of microns in length and less than one micro in diameter. Matrix: Polymer (polymeric composites) Metals (metal matrix composites) Ceramic (ceramic matrix composites) Carbon (carbon/carbon composites) 10.1.2 Fillers and matrix for nanocomposites Fillers: Carbon nanotubes Graphene Matrix: Polymer (polymeric composites) Carbon (carbon/carbon composites) The major concern of CNT- or graphene-based nanocomposites is improvement in physical property (such as electrical conductivity) rather than mechanical properties of the nanocomposites. 10.1.3 Reinforcement-matrix interface of composites Wettability: Interfacial bonding is due to adhesion between the reinforcement and the matrix and to mechanical keying. Cle