FROM SUGARCANE TO CARBON NANOSPHERES FOR TRIBOLOGICAL APPLICATIONS

International audienceFriction and wear phenomena are the main causes of the decrease in performances and durability of mechanical systems. The use of tribology, defined as the science that studies the phenomena of friction, wear and lubrication, is essential and constitutes an important economic issue. It is the role of lubrication to minimize friction and protect surfaces from wear. The strategy used to reduce these phenomena is to introduce a lubricant between the sliding surfaces. This lubricant can be solid, liquid or gaseous, and must prevent direct contact between surfaces, with specific properties such as friction reduction, anti-oxidizing or antiwear action. Pure lubricating bases (mineral or synthetic oil) cannot provide all protective functions, so that additives are added to improve their reducing properties of friction and wear. New lubrication strategies use dispersed nanoparticles in lubricants. The approach is to supply the sliding contact with solid particles, which can instantly form a protected low shearing tribological film. This work focuses on the synthesis of new friction reducer additives from local biomass, in order to produce ecofriendly lubricants. These new carbon phases are obtained using the spray-pyrolysis technique [1] with sugarcane from local biomass. It consists in nebulizing a solution of saccharose in the form of micro-droplets, transported to a tubular oven heated at temperatures ranging from 800°C to 1000°C, in order to obtain carbon nanospheres. The first results have permitted to evidence the effects of synthesis conditions (oven temperature, catalyst concentration and carrier gas pressure), on the nanoparticles morphology, using scanning electron microscopy. Raman spectroscopy gives us information about the graphitization degree of the carbon phase .The effect of an annealing process on these particles is studied in order to improve the nanospheres tribological propertie