▎ 摘　　要

NOVELTY - Preparing nano cellulose/acrylamide/graphene oxide self-healing hydrogel involves preparing cellulose raw material into powder, and immersing the powder in the mixed solution of sodium hydroxide (NaOH) and sodium sulfite (Na2SO3), and heating in a water bath at a temperature of 90-100 degrees C for 1-10 hours, then pouring out the waste liquid to obtain the powder after NaOH and Na2SO3 treatment. The mixed solution of NaOH and Na2SO3 is a NaOH solution with a concentration of 0.01-10 mol/L and a Na2SO3 solution with a concentration of 0.01-10 mol/L mixed in a volume ratio of 1:(0.1-10). The powder treated with NaOH and Na2SO3 with deionized water is boiled for 0.5-5 hours, and then poured out the waste liquid. The deionized water is replaced until the waste liquid is colorless, and then washed with deionized water as the washing liquid at room temperature until the washing liquid is neutral, and the powder after preliminary washing is obtained. USE - Method for preparing nano cellulose/acrylamide/graphene oxide self-healing hydrogel. ADVANTAGE - The method solves the problems of low mechanical strength of the existing cellulose hydrogel, poor dye adsorption effect, inability to be reused, and inability to self-heal. DETAILED DESCRIPTION - Preparing nano cellulose/acrylamide/graphene oxide self-healing hydrogel involves preparing cellulose raw material into powder, and immersing the powder in the mixed solution of sodium hydroxide (NaOH) and sodium sulfite (Na2SO3), and heating in a water bath at a temperature of 90-100 degrees C for 1-10 hours, then pouring out the waste liquid to obtain the powder after NaOH and Na2SO3 treatment. The mixed solution of NaOH and Na2SO3 is a NaOH solution with a concentration of 0.01-10 mol/L and a Na2SO3 solution with a concentration of 0.01-10 mol/L mixed in a volume ratio of 1:(0.1-10). The powder treated with NaOH and Na2SO3 with deionized water is boiled for 0.5-5 hours, and then poured out the waste liquid. The deionized water is replaced until the waste liquid is colorless, and then washed with deionized water as the washing liquid at room temperature until the washing liquid is neutral, and the powder after preliminary washing is obtained. The powder after preliminary cleaning is immersed in a hydrogen peroxide (H2O2) solution with a concentration of 0.1-5 mol/L, and then heated for 0.5-10 hours at a temperature of 90-100 degrees C, then washed with deionized water at room temperature, and finally freeze-dried to obtain the delignified powder. The delignified powder is uniformly dispersed in ionized water, and performed ultrasonic treatment for 60-300 minutes under the conditions of power of 200-500 watt and temperature of 0-30 degrees C. The upper layer of flocculent liquid is placed in a centrifuge, and centrifuged for 1-10 minutes at a speed of 2000-10000 revolutions/minute to obtain a nanocellulose dispersion. The mass ratio of the delignified powder to the volume of deionized water is 1 g: (100-1000) mL. The graphene oxide is added to the nano-cellulose dispersion, and under the conditions of an ultrasonic power of 200-500 watt and a temperature of 0-30 degrees C, ultrasonic treatment is performed for 1-200 minutes to obtain a nanocellulose-graphene oxide mixture. The mass ratio of the graphene oxide to the volume of the nanocellulose dispersion is 1 g: (100-1000) mL. The acrylamide, acrylic acid and NN-methylene bisacrylamide are added to the nanocellulose-graphene oxide mixture in sequence, under nitrogen, stirred at 2-50 revolutions/second, and stirred for 30-200 minutes. The potassium persulfate is then added, stirred for 0.5-30 minutes under nitrogen, stirring speed of 2-50 revolutions/second and room temperature to obtain the mixed liquid, poured the mixed liquid into the mold, and kept for 30-200 minutes, taken out the sample, and obtained the nanocellulose/acrylamide/graphene oxide self-healing hydrogel. The mass ratio of the nanocellulose-graphene oxide mixed liquid to acrylamide is 100:(5-15). The mass ratio of the nano-cellulose-graphene oxide mixed liquid to acrylic acid is 100:(0.1-1). The mass ratio of the nanocellulose-graphene oxide mixture to N-N-methylenebisacrylamide is 100: (0.05-0.1). The mass ratio of the nano-cellulose-graphene oxide mixed liquid and potassium persulfate is 100:(0.1-1).