Equipment and method for continuously preparing graphene powder directly dispersed in organic system

A method for continuously preparing graphene powder directly dispersed in an organic system, equipment used in the method comprising a pre-emulsification kettle, an emulsion-polymerization kettle and a spray dryer connected sequentially in series through pipelines;

• the equipment further comprising a feeding peristaltic pump arranged in series on a pipeline between the emulsion-polymerization kettle and the spray dryer;
• the pre-emulsification kettle being equipped with a first mechanical stirring device and an ultrasonic probe;
• a bottom of the pre-emulsification kettle being provided with a first control valve;
• the emulsion-polymerization kettle being equipped with a second mechanical stirring device and a heating device;
• a bottom of the emulsion-polymerization kettle being provided with a second control valve;
• and the method comprising:
• (S1) adding successively a graphene oxide aqueous dispersion, an emulsifier and an oil-soluble monomer into the pre-emulsification kettle, followed by adjusting pH to alkaline and dispersing at room temperature by using the first mechanical stirring device and the ultrasonic probe to obtain a pre-emulsified dispersion;
• wherein the oil-soluble monomer is an olefinic monomer;
• (S2) opening the first control valve and feeding the pre-emulsified dispersion into the emulsion-polymerization kettle;
• turning on the second mechanical stirring device and the heating device to heat the pre-emulsified dispersion to a first preset temperature under stirring;
• and adding an initiator to carry out an emulsion polymerization reaction;
• (S3) adjusting the emulsion-polymerization kettle to a second preset temperature;
• adding a reducing agent to reduce graphene oxide;
• and turning off the heating device;
• and
• (S4) opening the second control valve;
• and feeding a reaction mixture in the emulsion-polymerization kettle into the spray dryer through the feeding peristaltic pump, followed by drying at a third preset temperature to obtain the graphene powder;
• wherein the pre-emulsification kettle is configured for pre-emulsification of raw materials;
• the ultrasonic probe is configured to emulsify the oil-soluble monomer into micro-nano droplets and promote adsorption of the micro-nano droplets on a surface of a graphene oxide sheet, and an ultrasonic power of the ultrasonic probe is 200 W;
• the first mechanical stirring device is configured to assist emulsification of the oil-soluble monomer to allow the micro-nano droplets of the oil-soluble monomer and graphene oxide sheets to be uniformly dispersed in water;
• and a stirring speed of the first mechanical stirring device is 200˜400 r/min;
• the emulsion-polymerization kettle is configured for the emulsion polymerization reaction of the oil-soluble monomer;
• the heating device is configured to provide a required temperature for the emulsion polymerization reaction;
• the second mechanical stirring device is configured for uniform mixing of an emulsion polymerization reaction system;
• the feeding peristaltic pump is configured to pump the reaction mixture after the emulsion polymerization reaction in the emulsion-polymerization kettle into the spray dryer at a constant speed;
• and
• the spray dryer is configured to dry the reaction mixture into the graphene powder.