Search

CN-122010456-A - Additive for enhancing chloride ion permeability and application thereof

CN122010456ACN 122010456 ACN122010456 ACN 122010456ACN-122010456-A

Abstract

The invention belongs to the technical field of civil engineering materials, and particularly relates to an additive for enhancing chloride ion permeability and application thereof. The additive comprises an amino organic ligand modified aluminum-based metal organic framework material coated by polycarboxylic acid and nano calcium hydroxide. Aiming at the problems of coarsening of pore structures, poor anti-chloride ion performance and the like caused by insufficient hydration of solid waste cement prepared by high-doped iron tailing powder, the invention utilizes an amino organic ligand modified aluminum-based MOF material to realize electrostatic attraction and hydrogen bond synergistic adsorption of chloride ions, and simultaneously, polycarboxylic acid coating prevents the MOF material from agglomerating, so that the dispersibility and the compatibility in a cement system are improved, nano calcium hydroxide promotes the hydration of cement, the compactness of slurry is improved, and the nano calcium hydroxide and the amino organic ligand synergistic adsorption of the chloride ions are prevented from penetrating.

Inventors

  • GAO YUXIN
  • YAN SONGLING
  • ZENG CHAO
  • LIU MING
  • YE ZI
  • WANG FUTAO
  • HAN WENJIN
  • JIN ZIHAO
  • ZHANG RUI

Assignees

  • 中建西部建设建材科学研究院有限公司

Dates

Publication Date
20260512
Application Date
20251223

Claims (10)

  1. 1. An additive for enhancing resistance to chloride ion permeation comprising a polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic framework material, and nano calcium hydroxide.
  2. 2. An additive for enhancing resistance to chloride ion permeation according to claim 1, wherein said polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic framework material and nano calcium hydroxide are present in a mass ratio of 1:2-2:5.
  3. 3. An additive for enhancing resistance to permeation of chloride ions according to claim 1 or 2, wherein said polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic framework material has a particle size of 0.1 to 1 μm; and/or the particle size of the nano calcium hydroxide is less than 100nm, preferably 10-80 nm.
  4. 4. An additive for enhancing resistance to permeation of chloride ions according to claim 1 or 2, wherein said polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic framework material is prepared by a process comprising the steps of: (1) Adding an aluminum source precursor, an amino organic ligand and a surfactant into a solvent, performing ultrasonic treatment for a period of time, and then adding the mixture into a closed reaction kettle, and performing hydrothermal reaction at 100-150 ℃ for 6-24 h to obtain an amino organic ligand modified aluminum-based metal organic frame material; (2) Adding the amino organic ligand modified aluminum-based metal organic framework material prepared in the step (1) into a polycarboxylic acid solution, stirring or dispersing by ultrasonic for a period of time, standing for a period of time to finish physical adsorption, centrifuging to separate out a solid product, drying and grinding to obtain the amino organic ligand modified aluminum-based metal organic framework material.
  5. 5. An additive for enhancing permeation of chlorine ions according to claim 4, wherein said amino organic ligand is 2-amino terephthalic acid.
  6. 6. An additive for enhancing permeation of chlorine ions according to claim 4, wherein the molar ratio of said aluminum source precursor to said amino organic ligand is 1 (1.0-1.5).
  7. 7. The additive for enhancing chloride ion permeation resistance according to claim 4, wherein said polycarboxylic acid solution has a solid content of 10 to 30 wt%, and wherein said polycarboxylic acid is a polycarboxylic acid water reducing agent; Preferably, the polycarboxylic acid water reducer is an acrylic acid, methacrylic acid or maleic anhydride polycarboxylic acid water reducer.
  8. 8. An additive for enhancing permeation of chlorine ions according to claim 4, wherein the mass ratio of said amino organic ligand-modified aluminum-based metal organic framework material to said polycarboxylic acid in said polycarboxylic acid solution is 1:1.0-2.5.
  9. 9. The concrete is characterized by comprising a cementing material and the additive according to any one of claims 1-8, wherein the cementing material comprises cement clinker and solid waste admixture, and the mass fraction of the solid waste admixture in the cementing material is more than 30%.
  10. 10. The concrete of claim 9, wherein the solid waste admixture comprises iron tailings; and/or the additive is used in an amount of 1 to 3wt% based on the mass of the cementing material.

Description

Additive for enhancing chloride ion permeability and application thereof Technical Field The invention belongs to the technical field of civil engineering materials, and particularly relates to an additive for enhancing chloride ion permeability and application thereof. Background In recent years, the preparation of low-carbon cement by utilizing solid wastes has received considerable attention, and not only reduces carbon dioxide emission, but also reduces the dependence on non-renewable resources, thereby promoting the sustainable development of building materials. The iron tailings have excessive yield and low recovery rate, and a large amount of Iron Tailings Powder (ITP) is accumulated, resulting in serious environmental problems. In order to improve the comprehensive utilization rate of tailings, in particular to solve the problem that fine tailings are difficult to solve, many researchers use iron tailing powder to prepare low-carbon gelling materials. However, the main components of the iron tailing powder are SiO 2 (35% -83%) and Fe 2O3 (7% -47%), and the contents of active SiO 2 and Al 2O3 are low, so that after the mixing amount exceeds 30%, the cement hydration reaction is insufficient, the pore structure is coarsened, and the prepared concrete has low chloride ion permeation resistance. The anti-chloride ion permeability is an important index for measuring the durability of concrete, so that the development of the additive material for the high-doping-amount iron tailing powder cement capable of enhancing the anti-chloride ion permeability has important significance for practical engineering application. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide an additive for enhancing the permeability of anti-chloride ions and application thereof, which adopts an amino organic ligand modified aluminum-based metal organic framework material coated by polycarboxylic acid as a main body, adsorbs and fixes chloride ions, compounds nano calcium hydroxide, improves the reactivity of iron tailing powder, fills nano size, has a compact structure, and improves the permeability of anti-chloride ions of high-doping solid waste cement. Specifically, the invention provides the following technical scheme: An additive for enhancing resistance to chloride ion permeation comprising a polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic framework material, and nano calcium hydroxide. The amino organic ligand modified aluminum-based metal organic framework material comprises electropositive metal ion sites and amino functional groups, can realize cooperative adsorption with chloride ions (Cl -) through electrostatic attraction, hydrogen bonds and other action mechanisms, is coated on the surface of MOF to provide steric hindrance so as to prevent the agglomeration of the MOF and enhance the dispersibility and compatibility of the MOF in a cement system, is introduced with nano calcium hydroxide to provide crystal nucleus to promote hydration reaction, accelerates the reaction of solid waste and generates more C-S-H gel, so that micropores are filled, the pore structure is thinned, the permeability and diffusion coefficient of the material are obviously reduced, so that the chloride ions are more difficult to penetrate, and meanwhile, the immobilized chloride ions are accelerated to generate Freund' S salt with the aluminum phase iron phase in the solid waste under the promotion of CH. The components have complementary effect, and endow the cement concrete material with excellent chlorine ion permeation resistance. Preferably, the mass ratio of the polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic framework material to the nano calcium hydroxide is 1:2-2:5. If the proportion is too high, the consumption of nano calcium hydroxide is insufficient, and the nano calcium hydroxide is a solid waste accelerating activator, and if the consumption is insufficient, the effect of exciting the activity of solid waste cannot be fully achieved, and if the proportion is too low, the MOF effect is reduced, the high adsorptivity of the MOF effect cannot be reflected, and the effect of resisting chloride ions is weakened. Preferably, the particle size of the polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic frame material is 0.1-1 mu m, and if the particle size is too large, the specific surface area is reduced, the capturing efficiency and the fixed capacity are obviously reduced, and the filling efficiency is low, so that the polycarboxylic acid coated amino organic ligand modified aluminum-based metal organic frame material cannot be uniformly dispersed. And/or the nano calcium hydroxide has a particle size of less than 100nm a, more preferably 10-80 a nm a, to provide nucleation-induced hydration product generation. Preferably, the preparation method of the polycarboxylic a