▎ 摘　　要

NOVELTY - Preparation of in-situ reduction graphene engine oil energy-saving improver involves: (1) preparing a graphene oxide ethanol solution; and (2) mixing absolute ethanol and base oil, then pouring into the graphene oxide ethanol solution for dilution, placing in an ultrasonic stirring tank, so that the solution is evenly dispersed, turning on a magnetic stirrer, then putting the solution, stirring and mixing with the magnetic stirrer to get a mixed solution, adding reducing agent hydrazine hydrate to the mixed solution for reaction, continuously stirring to ensure that the reducing agent reduces graphene oxide to obtain ethanol graphene oil after the reaction is completed, putting the ethanol graphene oil into a blast drying oven, drying at 60-90 degrees C, setting the drying time to more than 48 hours, and removing ethanol from the ethanol graphene oil. USE - The method is useful for preparing in-situ reduction graphene engine oil energy-saving improver. DETAILED DESCRIPTION - Preparation of in-situ reduction graphene engine oil energy-saving improver involves: (1) preparing a graphene oxide ethanol solution by (1a) pre-oxidation stage by adding perchloric acid and graphite powder to a container filled with concentrated sulfuric acid, maintaining the container with mixed solution in a water bath at a constant temperature of 60-90 degrees C for more than 1 hour, and then naturally cooling to room temperature, (1b) carrying out low-temperature reaction stage by filling the water bath with an ice water, maintaining the temperature at 0 degrees C, slowly adding concentrated sulfuric acid and sodium nitrate to the pre-oxidized solution, controlling the solution temperature at less than 30 degrees C, ensuring that the layer structure of graphite itself is not destroyed, and adding potassium permanganate until the solution turns light green and gradually becomes viscous, (1c) carrying out moderate-temperature reaction stage by setting the temperature of the water bath to 30-40 degrees C after the reaction is completed, and heat preserving for 1.5-2.5 hours until the solution becomes dark green and viscous, and (1d) carrying out high-temperature reaction stage by placing a beaker in a magnetic mixer, adding a small amount of deionized water to the beaker, quickly heating at 96-99 degrees C, setting the speed of the magnetic mixer to 100-200 rpm, stirring for 12-17 minutes, after the high-temperature reaction is completed, cooling to room temperature, adding a large amount of deionized water, continuously stirring and observing the solution, simultaneously adding 3% hydrogen peroxide to the solution until no more bubbles are generated, after the reaction is terminated, adding hydrogen peroxide to further oxidize and layer graphene, mixing concentrated hydrochloric acid and deionized water in a volume ratio of 1:(10-20), using the obtained solution to wash the resulting solution 2-3 times in a centrifuge, then using absolute ethanol to wash, and constantly testing under a pH meter until the solution is neutral; and (2) mixing absolute ethanol and base oil in a volume ratio of 1:(1-5), then pouring into the graphene oxide ethanol solution for dilution, placing in an ultrasonic stirring tank, so that the solution is evenly dispersed, turning on a magnetic stirrer, then putting the solution, stirring and mixing with the magnetic stirrer to get a mixed solution, adding a proper amount of reducing agent hydrazine hydrate to the mixed solution for reaction, during the process, slowly adding the reducing agent, continuously stirring to ensure that the reducing agent reduces graphene oxide as much as possible, after the reaction is completed, obtaining ethanol graphene oil, putting the ethanol graphene oil into a blast drying oven, drying at 60-90 degrees C, setting the drying time to more than 48 hours, and removing ethanol from the ethanol graphene oil.