Carbon fiber-reinforced metakaolin-based geopolymer composites

Patent metadata

Field	Value
Publication number	US-12473232-B2
Application number	US-202117792502-A
Country	US
Kind code	B2
Filing date	Jan 29, 2021
Priority date	Jan 29, 2020
Publication date	Nov 18, 2025
Grant date	Nov 18, 2025

Abstract

Methods for making carbon-fiber reinforced geopolymer composites are provided. The methods produce metakaolin-based geopolymer composites in which multiwalled carbon nanotubes and/or carbon nanofibers are well dispersed in an metakaolin-based geopolymer matrix. The mixing protocols of the methods used to produce carbon-fiber reinforced geopolymer composites produce composites with reduced porosity, high elastic moduli, high strength, and/or high fracture toughness.

First claim

What is claimed is:

1 . A carbon nanotube-reinforced geopolymer composite comprising:
a potassium metakaolin-based geopolymer matrix; and multiwalled carbon nanotubes dispersed in the potassium metakaolin-based geopolymer matrix, wherein the concentration of the multiwalled carbon nanotubes is in the range from 0.55 to 1.5 weight percent, per weight of potassium metakaolin in the potassium metakaolin-based geopolymer matrix; the carbon nanotube-reinforced geopolymer composite having a porosity in the range from 5.5% to 7.5%, an indentation modulus in the range from 7.5 to 8.5 GPa, and a fracture toughness in the range from 0.58 Mpa·sqrt(m) to 0.65 MPa·sqrt(m), wherein the carbon nanotube-reinforced geopolymer composite is free of organic surfactants and organic dispersing agents and the multiwalled carbon nanotubes are not functionalized with surface carboxy groups.

2 . The composite of claim 1 having a plastic viscosity of at least 10 Pa·s.

3 . The composite of claim 1 having a yield shear stress of at least 50 Pa.

4 . A method of making a carbon nanotube reinforced geopolymer composite, the method comprising:
forming an aqueous dispersion of multiwalled carbon nanotubes; ultrasonicating the aqueous dispersion; subsequently dissolving potassium hydroxide and silica in the aqueous dispersion to form a waterglass solution; adding potassium metakaolin to the waterglass solution to form a geopolymer solution; mixing and degassing the geopolymer solution in a centrifugal mixer; and curing the geopolymer solution with continuous mixing to form the carbon nanotube reinforced geopolymer composite, wherein the concentration of the multiwalled carbon nanotubes in the carbon nanotube-reinforced geopolymer composite is in the range from 0.55 to 1.5 weight percent, per weight of potassium metakaolin; the carbon nanotube-reinforced geopolymer composite having a porosity in the range from 5.5% to 7.5%, an indentation modulus in the range from 7.5 to 8.5 GPa, and a fracture toughness in the range from 0.58 MPa·sqrt(m) to 0.65 MPa·sqrt(m), wherein the carbon nanotube-reinforced geopolymer composite is free of organic surfactants and organic dispersing agents and the multiwalled carbon nanotubes are not functionalized with surface carboxy groups.

Assignees

• Univ Northwestern

Inventors

• Akono Ange-Therese
• Chen Jiaxin

Classifications

• C04B2201/50

  for the mechanical strength · CPC title

• C04B2111/00181

  Mixtures specially adapted for three-dimensional printing (3DP), stereo-lithography or prototyping · CPC title

• C04B14/026 Primary

  of particular shape, e.g. nanotubes · CPC title

• Y02P40/10

  Production of cement, e.g. improving or optimising the production methods; Cement grinding · CPC title

• C04B28/006 Primary

  containing mineral polymers, e.g. geopolymers of the Davidovits type · CPC title