BACKGROUND
Traditionally, metals have been used to protect against electromagnetic interference; however, their weight and machinability constraints have led to an increased usage of composites. To address the issue of low conductivity in composites, intrinsically conducting polymers or the inclusion of conductive fillers (e.g., carbon black, carbon fibers, carbon nanotubes) have been employed. Unfortunately, these materials have less shielding effect than metals, even at high volume fractions of fillers (which have an additional detriment of reducing toughness and ductility of the composite). Additionally, high volume fractions of fillers are difficult to manufacture. Graphene is a two-dimensional one atom thick layer of carbon atom, and it has been identified as a nanofiller for improving the mechanical, electrical, and thermal properties for polymer composite materials. However, the addition of graphene to polymer composites, through addition to the epoxy matrix is a complex process. The graphene fillers are nano-sized and cannot be easily blended into the matrix through traditional methods.
SUMMARY OF TECHNOLOGY
OSU researchers have developed a unique method to overcome the problematic complexities of graphene nanofiller addition to polymer composites. A flexible graphene film is created which is then dispersed in a highly conductive polymer carrier. The poor processability for many polymers requires the introduction of solubilizing or substituents, which can further complicate the synthesis. Specifically, a recent discovery that the addition of a mixture of poly vinyl pyrrolidone (PVP, an environmentally friendly polymer used in hygiene products) and polyaniline can drastically enhance the conductivity of the resulting blend enabling the production of flexible and conductive graphene films, since graphene is easily dispersible in PVP. PVP can be blended with every major resin matrix system used in polymer composites, improving the electrical and thermal conductivities of these materials. These films can be placed between prepreg layers or on the surface of the composite itself, allowing for diverse applicability in many settings, from aerospace and defense industrial applications to thermal foils and construction.
POTENTIAL AREAS OF APPLICATION
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Aerospace Industry
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Material and composite manufacturing (material strength)
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Thermal applications (thermal foils, for example)
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Construction applications
MAIN ADVANTAGES
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State-of-the-art method enabling graphene addition to polymer composites
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Broad market applicability
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Enhances conductivity and flexible properties
STAGE OF DEVELOPMENT