Recent progress in low-carbon binders

Processing, properties and applications of highly porous geopolymers: A review

https://cyberleninka.org/article/n/1159709.pdf

Recent advances in silica-alumina refractory: A review

Exergoeconomic assessment with reliability consideration of a green cogeneration system based on compressed air energy storage (CAES)

Preparation of mullite-TiB2-CNTs hybrid composite through spark plasma sintering

Geopolymer foams, as a new type of potential eco-friendly building material, are increasingly being discussed in the literature. This study reports the synthesis and characterization of geopolymer foams using hydrogen peroxide (H2O2) solution as pore-forming agent and oil as the stabilizing agent. The geopolymer foams with low bulk densities (0.37

Porosity, mechanical and insulating properties of geopolymer foams using vegetable oil as the stabilizing agent

High-porosity metakaolin-based geopolymer foams (GFs) were fabricated by a gelcasting technique using hydrogen peroxide (foaming agent) in combination with Tween 80 (surfactant). Slurries processed in optimized conditions enabled to fabricate potassium based GFs with a total porosity in the range of ∼67 to ∼86 vol% (∼62 to ∼84 vol% open), thermal conductivity from ∼0.289 to ∼0.091 W/mK, and possessing a compressive strength from ∼0.3 to ∼9.4 MPa. Moreover, factors that influence the compressive strength, the porosity, the thermal conductivity, and the cell size distribution were investigated. The results showed that the cell size and size distribution can be controlled by adding different content of surfactant and foaming agent. The foamed geopolymer can also be used as adsorbents for the removal of copper and ammonium ions from wastewater. The foams, due to their low thermal conductivity, could also be used for thermal insulation. It was also possible to produce geopolymer formulations that could be printed using additive manufacturing technology (Direct Ink writing), which enabled to produce components with nonstochastic porosity.

High-porosity geopolymer foams with tailored porosity for thermal insulation and wastewater treatment

Metakaolin-based geopolymer foams were synthesized by mechanical frothing, using hydrogen peroxide as additional foaming agent; three vegetable oils were added in order for the saponification reaction to occur. The combined use of the two foaming techniques (mechanical frothing and H 2 O 2 decomposition) led to interconnected porosity: the in-situ formation of the soap molecules generated by the saponification reaction was exploited to generate macro-porosity. This combined route enabled the production of geopolymer foams with a range of total porosity and strength values, with an optimal sample possessing a total porosity of to ∼81 vol%, an open porosity of ∼79 vol%, and a compressive strength of ∼3.1 MPa. Moreover, factors that influence the compressive strength, the porosity, and the pore size distribution were investigated. The results showed that the cell size and cell window size can be controlled by adding different oils and different contents of peroxide.

Chengying Bai

Papers

Processing, properties and applications of highly porous geopolymers: A review

Porosity, mechanical and insulating properties of geopolymer foams using vegetable oil as the stabilizing agent

High-porosity geopolymer foams with tailored porosity for thermal insulation and wastewater treatment

High strength metakaolin-based geopolymer foams with variable macroporous structure

High-porosity geopolymer membrane supports by peroxide route with the addition of egg white as surfactant