▎ 摘　　要

NOVELTY - Method for preparing low-temperature planetary ball-milled sodium chloride particles, involves charging sodium chloride to ball milling tank in planetary ball mill, adding grinding ball to ball milling tank, and sealing ball milling tank, where the mass ratio of grinding ball and sodium chloride is (20-40):1, (b) introducing dry inert gas to ball milling tank for discharging air in ball milling tank, and placing the ball milling tank in inert gas environment and sealing, (c) introducing cooling medium to planetary ball mill at low temperature, maintaining the temperature of ball milling process to 15-20 degrees C at a speed of 300-500 rpm for 1-5 hours, (d) after performing post-treatment ball milling, naturally heating to room temperature, separating grinding ball and ball-milled material, and screening obtained ball-milled material for removing grinding residue to obtain low-temperature planetary ball-milled sodium chloride particle. USE - The method is used for preparing low-temperature planetary ball milling sodium chloride particles, which are used for preparing graphene-based porous flexible sensors (all claimed). ADVANTAGE - The method ensures sodium chloride to be easily soluble in water, does not allows to react with flexible substrate, and completely removes when preparing porous flexible sensor, and is environmentally-friendly, and the graphene-based porous flexible sensor has uniform pore size and improved pressure sensitivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) the low temperature planetary ball-milled sodium chloride particle prepared by above-mentioned method, where the yield of required sodium chloride particle size interval is 80-95%, and after passivating surface of target product, the particles are smooth; and (2) a graphene-based porous flexible sensor prepared using above-mentioned low temperature planetary ball-milled sodium chloride particle, which involves (i) preparing sodium chloride-sacrificial mold, filling target product low-temperature star-milled sodium chloride particle obtained by ball milling in silica gel mold, performing preliminary pressurization using pressure block, contacting low-temperature planetary ball with sodium chloride particles, wetting low-temperature planetary ball-milled sodium chloride particles using water mist method, and naturally air-drying sodium chloride to obtain sodium chloride sacrificial mold, (ii) using graphene-polydimethylsiloxane flexible conductive base material for pouring sodium chloride-polydimethylsiloxane uniform mixture, pouring graphene-polydimethylsiloxane uniform mixture on sodium chloride sacrificial mold, completely soaking sodium chloride and sacrificial mold, and curing to obtain cured product, and (iii) removing sodium chloride particles to generate micro-tunnel pore structure, performing edge cutting treatment on cured product, exposing partially sodium chloride particles, and soaking in water, and completely dissolving sodium chloride particles to obtain graphene-based porous flexible sensor with micro-channel effect.