Biomimetic composite material and preparation method thereof

A method for preparing a biomimetic nacre material, comprising the steps of:

• S1:
• pulverizing biomass fibers, and dissolving in distilled water together with an inorganic nanomaterial to form a nano suspension, and colloid milling at 2,500˜3,000 rpm for 5˜10 hours, and further treating in a disc mill at 2,500˜3,000 rpm for 5˜10 hours to obtain a nanomaterial-wood fiber composite suspension with a particle size of 50˜500 nm;
• S2:
• mixing the nano suspension with mixed salt solution composed of 3.632 g/L NaCl, 0.113 g/L Na2SO4, 0.332 g/L NaHCO3, 0.328 g/L MgCl2.6H2O, 0.284 g/L CaCl2 and 0.177 g/L KCl, reacting at 40˜60° C. for 36˜60 hours to obtain a mineralized nano wood fiber suspension, pre-cooling to 1˜5° C., freeze-casting in a liquid nitrogen environment at −196˜−30° C., and freeze-drying at −30˜20° C. under 10˜40 Pa for 12˜48 hours to obtain a layered nacre structure-imitating base body;
• and
• S3:
• soaking an organic polymer material in the suspension of the layered nacre structure-imitating base body obtained in step S2, and hot pressing at 100˜250° C. under 0.8˜20 MPa for 0.5˜24 hours to obtain a finished product containing the organic polymer material 1˜10 mass %, wherein:
• in step S1, a mass ratio of the biomass fibers, the inorganic nanomaterial and the distilled water is 1:(5×10−4˜0.2):20.