Rice University graphene foam, combined into a tough epoxy conductive composite
Rice University scientists have created a better epoxy resin electronic applications. Epoxy resin Rice chemist James Tour of the invention in combination with laboratory \”super\” graphene foam, many sturdy than pure epoxy, epoxy resin composites is better than other conductive properties, while maintaining material low density. By adding a conductive filler, can be improved currently in use would weaken the structure of an epoxy material. the epoxy resin itself is an insulator, commonly used in coatings, adhesives, electronics, industrial tools, and composite structures. Metal or carbon fillers are usually added for applications required conductivity, electromagnetic shielding applications. But the tradeoff: more by weight of filler to a better compressive strength and conductivity to the price, and the composite material becomes more difficult to process. Foam dimensional Rice (Rice) solution in a laboratory made of metal nano-substituted graphene or carbon, graphene sheet thickness of only one carbon-carbon atoms. Tour Laboratory materials scientist at Rice University Pulickel Ajayan, Rouzbeh Shahsavari, Lou Jun Beijing University of Aeronautics and Astronautics and Hajime research cooperation project from the epoxy resin injected into the three-dimensional scaffold inspiration, including graphene aerogels, foams and stent various processes. New technologies made stronger stent embodiment polyacrylonitrile (PAN), it is a powdered polyacrylonitrile polymer resin, as a carbon source, mixed with nickel powder. In the four-step process, they are cold material to densify it, heated in a furnace to make graphene into PAN, resulting chemically treated material to remove the nickel, and an epoxy resin using a vacuum pulled into the existing porous material. \”Graphene is a single layer of graphene foam,\” Tour said. \”Thus, in practice, the whole foam is a macromolecule. When the epoxy resin foam permeate then hardened, due to the embedding of the stent graphene, epoxy will be in a position of any bend stress is applied to the monolith at other locations this will ultimately lead to stiffen the entire structure. \”According to the researchers, the foam content of 32% by a spherical composite density is slightly higher, but the measure of electrical conductivity of about 14 Siemens per centimeter (ohm conductivity reverse or ). Without increasing the weight of the compound of the foam, but it is 7 times the compressive strength of the pure epoxy. Simple interlock between the graphene and graphene epoxy also helps to stabilizeStructure. Tour said: \”When the epoxy resin permeation graphene then hardened foam, epoxy foam is trapped in the graphene micron-sized area.\” Lab ante multiwall carbon nanotubes by mixing the foam into the graphene . Researchers said nanotube acting as a reinforcing material in combination with graphene, the hardness of the composite material 1732% higher than pure epoxy, conductive performance is improved nearly three times, about 41 Siemens (Siemens) / cm, much higher almost all of those based on epoxy composites reported to date. Tour is expected that the process will be extended for an industrial scale. \”People need only one oven large enough to produce the final part,\” he said. \”However, this has always been, by cold pressing, then heating the manufacture of large metal parts.\” He said, this material may initially substituted carbon composite resins, such carbon composite resin and the prepreg for aerospace structural reinforcement tennis rackets and other material to the fabric.