Conductive inks, adhesives and coatings made with exfoliated graphite, applied to making electrical components and circuits

Abstract

Inks, paints and electrically conductive adhesives are important industrial products, with a global sales reaching US$ 3 billion/year and CAGR of 4-6%. They are used by many different industrial sectors including: automakers, IT, electric materials, energy. The impressive success and perspective potential uses of these materials sustain a sizable R&D activity, which is documented in many patents and publications. This project explores a new finding made by the proponent which is a procedure for making graphitic aqueous dispersions, stabilized by cellulose with unprecedented features that justify this project: i) the graphite exfoliating agent is "green"; ii) the processes involved are mild, which preserves the particle lateral dimensions iii) applying the dispersions on top of paper and cellulosic substrates produces flexible conductive films that are plasticizable; iv) the electrical resistance of films can be tuned by adjusting the relative concentrations of cellulose and graphite, as well as its degree of orientation; v) we have obtained graphitic films with resistances as low as 0,3 ohm/square. These dispersions lay the foundation of a platform for the production of electrical materials that are also part of the proposal: circuit boards, conductive tracks, printable electrodes, heaters and micro-heaters and a conductive adhesive tape. The current objective is to build up a pipeline of new inks, paints, adhesives and coatings increasing the production scale and exploring new possibilities in printed circuitry (2D and 3D) that are flexible and wearable, electrodes, miniaturized heaters, low power heaters, anti-static and anti-friction coatings, plasticizable graphite for molding and sensors. The methodology includes basic research activities in materials and R&D activities on paints and adhesives, adjusted to market demand and new technologies. The already comercialized products include teaching aid kits for electricity and electrochemistry, which may produce sizeable revenue in 2018. The expected results are: i) a profitable and sustainable industrial and services activity, backed by our recent invention and protected intelectual property; ii) replacement of expensive metals by graphite/cellulosic composites; iii) introduction of a new materials family, that is part of a "green" initiative. The expected impacts are: value creation, with quality jobs, contributing to the appearance of new products in different industrial sectors and decreasing the actual cost of products and services. (AU)