Bionic fiber adsorptive material with multi-adsorption sites and preparation method and use thereof

A preparation method of a bionic fiber adsorptive material with multi-adsorption sites comprising the following steps:

• step S1, preparation of a carboxylated nanocellulose:
• adopting a TEMPO/NaBr/NaClO oxidation system to oxidize a biomass fiber, and regulating an oxidation level by controlling reaction conditions to obtain the carboxylated nanocellulose;
• step S2, preparation of a polyethyleneimine polymer modified by (ethylenedithio)diacetic acid containing N and S sites:
• performing a first amidation reaction of (ethylenedithio)diacetic acid with a polyethyleneimine at a first temperature to obtain polyethyleneimine polymer modified by (ethylenedithio)diacetic acid containing N and S sites;
• step S3, preparation of a polyethyleneimine polymer modified by dopamine containing O and N sites:
• performing a second amidation reaction of a polycarboxylic acid with dopamine at a second temperature;
• when the second amidation reaction is complete, continuing to add polyethyleneimine to perform a third amidation reaction to obtain polyethyleneimine polymer modified by dopamine containing O and N sites;
• wherein the polycarboxylic acid is oxalic acid, citric acid or 1,2,3,4-butanetetracarboxylic acid;
• step S4, preparation of a polyethyleneimine polymer modified by hyperbranched polycarboxylic acid containing N and O sites:
• performing a fourth amidation reaction of hyperbranched polycarboxylic acid with polyethyleneimine at a third temperature to obtain the polyethyleneimine polymer modified by hyperbranched polycarboxylic acid containing the N and O sites;
• and
• step S5, blending the carboxylated nanocellulose obtained in the step S1, the polyethyleneimine polymer modified by (ethylenedithio)diacetic acid containing the N and S sites obtained in the step S2, the polyethyleneimine polymer modified by dopamine containing the O and N sites obtained in the step S3, the polyethyleneimine polymer modified by hyperbranched polycarboxylic acid containing the N and O sites obtained in the step S4, and graphene oxide by a blending method to prepare a spinning solution, continuously spinning the spinning solution to form a fiber with multiple functional groups at a speed of 1-4 cm/s by using a coaxial spinning method, spraying 5 wt % to 15 wt % of a crosslinking agent in a total fiber mass on the fiber by a spraying mode under vacuum filtration conditions with a vacuum having a degree of 0.01 MPa to 0.04 MPa to crosslink for 10-30 minutes, infiltrating the crosslinking agent into the fiber relying on the vacuum, and freeze-drying for 24-48 hours to obtain the bionic fiber adsorptive material with multi-adsorption sites;
• wherein the material is rich in multi-adsorption sites, that is, N, O and S sites that have chelating performance for heavy metal ions;
• adjusting content of each adsorption site in the material by regulating a ratio of each component in the spinning solution,
• wherein the crosslinking agent is epichlorohydrin.