Comparative Assessment of Conventional and Microwave Curing Synthesis Routes for Metakaolin-Based Porous Geopolymers:...

Area of Science:

• Materials Science
• Environmental Science
• Green Chemistry

Background:

• Geopolymers are increasingly relevant for environmental applications, particularly as sustainable adsorbent materials.
• Enhancing geopolymer porosity is crucial for their effectiveness, but synthesis methods must be energy-efficient and environmentally conscious.

Purpose of the Study:

• To compare conventional oven curing and microwave-assisted curing for synthesizing porous metakaolin-based geopolymers using hydrogen peroxide.
• To evaluate the structural, physical, and chemical properties of the synthesized geopolymers.
• To conduct a quantitative environmental assessment of the synthesis routes based on green chemistry principles.

Main Methods:

• Synthesis of porous metakaolin-based geopolymers using hydrogen peroxide as a foaming agent.
• Comparison of conventional oven curing and microwave-assisted curing.
• Characterization using XRD, FT-IR, SEM/EDS, TGA, and density-porosity analyses.
• Environmental assessment using DOZN™ software.

Main Results:

• Hydrogen peroxide addition did not alter the geopolymer structure, confirmed by FT-IR and XRD.
• Porosity significantly increased with hydrogen peroxide, reaching up to 67% with microwave curing.
• Microwave-assisted curing reduced synthesis time by ~80% and created a more interconnected macroporous structure.
• Microwave curing showed a lower overall environmental impact, mainly due to improved energy efficiency.

Conclusions:

• Microwave-assisted synthesis is a more sustainable and efficient route for producing highly porous, hydrophilic geopolymers.
• These materials show strong potential for the adsorption of aqueous pollutants in environmental applications.
• The study highlights the benefits of green chemistry principles in materials synthesis.