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CN-121975526-A - Improved composite material for treating saline-alkali soil and preparation method thereof

CN121975526ACN 121975526 ACN121975526 ACN 121975526ACN-121975526-A

Abstract

The invention discloses an improved composite material for treating saline-alkali soil and a preparation method thereof, and relates to the technical field of saline-alkali soil improvement; the modified composite material for treating the saline-alkali soil consists of an acrylic acid and polyaspartic acid potassium graft modified nano-alumina composite material and a zwitterionic cellulose-based hydrogel, wherein the acrylic acid and polyaspartic acid potassium graft modified nano-alumina composite material is loaded on a network of the zwitterionic cellulose-based hydrogel, so that the comprehensive fixation of anions and cations is realized, the migration path of salt ions is prolonged, the salt isolation performance is improved, meanwhile, the gel phase swells and the particle phase does not swell after meeting water, the gel phase swells and the particle phase cooperatively form a multistage water absorption channel, the water retention performance is further enhanced, and the water retention capacity of the zwitterionic cellulose-based hydrogel is not influenced by the shielding effect of salt ions, and the improved composite material for treating the saline-alkali soil is endowed with excellent salt resistance water retention performance.

Inventors

  • ZHANG MEI
  • HAN DONGLIANG
  • BIAN QIANQIAN
  • WANG RUJIA
  • ZHANG JIAXIN

Assignees

  • 长春师范大学

Dates

Publication Date
20260505
Application Date
20260407

Claims (7)

  1. 1. The improved composite material for treating the saline-alkali soil is characterized by comprising, by weight, 0.8-1.0 part of an acrylic acid and potassium polyaspartate grafting modified nano-alumina composite material and 10-15 parts of a zwitterionic cellulose-based hydrogel, wherein the acrylic acid and potassium polyaspartate grafting modified nano-alumina composite material comprises, by weight, 5-10 parts of quaternary ammonium salt functionalized nano-alumina, 10-20 parts of acrylic acid and 1-3 parts of potassium polyaspartate.
  2. 2. A method for preparing the improved composite material for treating saline-alkali soil according to claim 1, which is characterized by comprising the following steps: S1, dissolving 4.65g of 1, 3-propane sultone in 10mL of anhydrous acetonitrile to form a dropping liquid for standby, adding 4.0g of 4-vinylpyridine into a three-necked flask filled with 40mL of anhydrous acetonitrile, cooling to 0-5 ℃ in an ice bath, slowly adding the dropping liquid through a dropping funnel under stirring at 600-800rpm, controlling the dropping time to be 40-50min, stirring for 24-48h at room temperature after complete addition, carrying out suction filtration, washing a filter cake with cold anhydrous acetonitrile for 3-5 times, and drying to obtain a zwitterionic monomer; S2, dispersing 3.0-4.0g of cellulose powder in 150mL of 35 ℃ deionized water, stirring for 20-30min to form solution A for standby, dispersing sodium carboxymethyl cellulose in 50mL of 25 ℃ deionized water, stirring for 10-20min to form solution B for standby, mixing solution A and solution B, adding 1.5-3.0g of the zwitterionic monomer in the step S1, stirring for 30-40min, introducing nitrogen into the mixed solution for 10-15min, adding 20-50mgN, N' -methylenebisacrylamide, stirring for 10-20min, rapidly adding 30-60mg of ammonium persulfate, stirring for 10-20S, immediately injecting into a mold, removing air, placing the whole mold in a 65 ℃ oven for reaction for 1-2h, obtaining preliminary solid gel, soaking the gel with deionized water until the pH of the washing solution is 7.0, pre-freezing the gel at-20 ℃ for 4-6h, and freezing the gel at-80 ℃ for 36-72h to obtain the amphoteric cellulose; S3, adding 0.8-1.0g of acrylic acid and polyaspartic acid potassium grafted modified nano aluminum oxide composite material into 20mL of absolute ethyl alcohol, performing ultrasonic dispersion for 20-30min to form a dispersion liquid for standby, weighing 10.0-15.0g of the zwitterionic cellulose-based hydrogel in the step S2, crushing into small pieces of 3mm, adding into 200mL of deionized water, fully swelling for 50-60min, adding the dispersion liquid, stirring at a low speed of 50-100rpm for 2-4h, taking out the loaded composite gel, transferring the loaded composite gel into a mold, standing and solidifying in a 70 ℃ oven for 1-2h, immersing the solidified composite gel in 500mL of deionized water for 24h, changing deionized water every 4h, pre-freezing for 4-6h before-20 ℃ and then freeze-drying for 36-72h at-80 ℃ to obtain the improved composite material for treating saline-alkali soil.
  3. 3. The method for preparing an improved composite material for treating saline-alkali soil according to claim 2, wherein the sodium carboxymethylcellulose is added in an amount of 5.0-6.0g in the step S2.
  4. 4. The method for preparing the modified composite material for treating the saline-alkali soil according to claim 3, wherein the method for preparing the acrylic acid and polyaspartic acid potassium graft modified nano aluminum oxide composite material is characterized by comprising the following steps: (1) Adding 1.0-2.0g of nano alumina into a round-bottom flask containing 80mL of absolute ethyl alcohol, performing ultrasonic dispersion for 20-30min, slowly adding 2mL of deionized water, dropwise adding 3-aminopropyl triethoxysilane under the stirring of 600-800rpm, installing a reflux condenser, heating to 60-70 ℃, magnetically stirring and refluxing for 12-16h under the protection of nitrogen at 800-1000rpm, cooling to room temperature, centrifuging, alternately washing a solid with ethanol and deionized water for 3-5 times, and finally performing vacuum drying at 80 ℃ to obtain the aminopropyl functionalized nano alumina; (2) 1.0-2.0g of the aminopropyl functionalized nano alumina in the step (1) is weighed and added into 100mL of ethanol solution with the mass fraction of 50%, ultrasonic dispersion is carried out for 20-30min, 50mL of sodium hydroxide solution with the mass fraction of 1.9% is added, stirring is carried out for 0.5-1h, 3-bromopropene is slowly dripped into the solution through a constant pressure dropping funnel under the stirring of 800-1000rpm, the temperature is raised to 40 ℃, reflux stirring is carried out for 18-24h, then acetic acid is used for regulating the pH value to 7.0, centrifugation is carried out, the precipitate is alternately washed for 3-5 times by ethanol and deionized water, and finally, the solution is dried in vacuum at 50 ℃ to obtain the quaternary ammonium salt functionalized nano alumina; (3) Neutralizing 1.0-2.0g of acrylic acid with a sodium hydroxide solution to pH 5.0-6.0, adding polyaspartic acid potassium, stirring for 10-20min to form a monomer solution for standby, weighing 0.5-1.0g of quaternary ammonium salt functionalized nano alumina in the step (2), adding into a four-necked flask with a stirring device, adding 20mL of deionized water, stirring for 20-30min, slowly adding the monomer solution into the flask, stirring for 30-40min at 50 ℃ and 200-350rpm, heating to 70 ℃, rapidly adding 5mL of ammonium persulfate solution with the mass fraction of 8-10%, reacting for 2-3h under the stirring of 70 ℃ and 300-350rpm, cooling after the reaction is finished, performing suction filtration, collecting precipitate, centrifugally washing 3-5 times with an ethanol solution with the mass fraction of 50%, drying in a 60 ℃ and finally crushing, and obtaining the acrylic acid and polyaspartic acid potassium graft modified nano alumina composite material through a screen with the pore diameter of 40-80 meshes.
  5. 5. The method of claim 4, wherein in the step (1), 3-aminopropyl triethoxysilane is added in an amount of 1.0-2.0mL.
  6. 6. The method of claim 5, wherein in the step (2), 3-bromopropene is added in an amount of 0.12-0.16mL.
  7. 7. The method for preparing a modified composite material for treating saline-alkali soil as claimed in claim 6, wherein in the step (3), the adding amount of the potassium polyaspartate is 0.1-0.3g.

Description

Improved composite material for treating saline-alkali soil and preparation method thereof Technical Field The invention belongs to the technical field of saline-alkali soil improvement, and particularly relates to an improved composite material for treating saline-alkali soil and a preparation method thereof. Background The salinization of the soil widely occurs in arid and semiarid regions, which constitutes a great threat to sustainable agriculture development, the essence of the formation of the saline-alkali soil is that soluble salts are redistributed in the soil, the salt accumulated on the surface layer of the soil exceeds a normal value, the salinization phenomenon of the soil becomes more severe under the dual effects of climate change and human activity, serious negative influence is generated on the physical and chemical properties of the soil, plant growth and agriculture development are seriously hindered, and threat is caused to ecological environment and engineering construction. The saline-alkali soil is mainly formed by natural factors and artificial factors, wherein the natural factors comprise climate, topography, soil texture and the like, the artificial factors comprise an unreasonable irrigation mode, an imperfect drainage system, an improper land utilization mode and the like, the saline-alkali soil is one of the main types of the desertification soil in China, effective measures comprise hydraulic engineering, biological measures, chemical improvement and the like, but due to the problems of drought and water shortage, high manufacturing cost, high transportation cost and the like in the desertification area, part of improvement methods are not applicable, salt ions migrate to the soil surface along with the reduction of groundwater level and the evaporation of water, so that the salt content of the soil surface layer is further increased, more serious salt accumulation results are caused on the saline-alkali soil, and therefore, the exploration of a new way for improving the saline-alkali soil with water conservation and high efficiency becomes an important research direction for ecological agriculture development. The prior art mainly has the following problems: The water holding capacity and the salt isolation capacity of the common improved materials are insufficient, so that the improvement effect of the saline-alkali soil is limited. Disclosure of Invention Aiming at the situation, in order to overcome the defects of the prior art, the invention provides an improved composite material for treating saline-alkali soil, which comprises the following components in parts by weight, 0.8-1.0 part of an acrylic acid and potassium polyaspartate grafting modified nano-alumina composite material and 10-15 parts of zwitterionic cellulose-based hydrogel. The acrylic acid and polyaspartic acid potassium grafted modified nano alumina composite material comprises, by weight, 5-10 parts of quaternary ammonium salt functionalized nano alumina, 10-20 parts of acrylic acid and 1-3 parts of polyaspartic acid potassium. The preparation method of the acrylic acid and polyaspartic acid potassium grafting modified nano aluminum oxide composite material specifically comprises the following steps: (1) Adding 1.0-2.0g of nano alumina into a round bottom flask containing 80mL of absolute ethyl alcohol, carrying out ultrasonic dispersion for 20-30min, slowly adding 2mL of deionized water, dropwise adding 3-aminopropyl triethoxysilane under the stirring of 600-800rpm, installing a reflux condenser tube, heating to 60-70 ℃, magnetically stirring and refluxing for 12-16h under the protection of nitrogen at 800-1000rpm, cooling to room temperature, centrifuging, alternately washing solid matters with ethanol and deionized water for 3-5 times, and finally carrying out vacuum drying at 80 ℃, wherein the 3-aminopropyl triethoxysilane is introduced into an aminopropyl molecular chain functional shell through covalent bond grafting on the surface of nano alumina, and provides a static fixation and ion exchange salt isolation barrier on the basis of the original physical barrier effect of nano particles, wherein a hydrophobic propyl flexible spacer chain separates the terminal amino group from the surface of particles, so that the steric hindrance is reduced, the reactivity of amino groups is improved, meanwhile, the hydrophilic terminal amino groups form amphiphilic micro areas, hydrophilic sites are strongly held with water, the hydrophobic sites can inhibit invalid evaporation caused by the action, and further distribution caused by the action of the excessive capillary force, and the optimal water retention performance of the nano alumina can be obtained; (2) 1.0-2.0g of the aminopropyl functionalized nano alumina in the step (1) is weighed and added into 100mL of ethanol solution with the mass fraction of 50%, ultrasonic dispersion is carried out for 20-30min, 50mL of sodium hydroxide solution with the mass fra