Fabrication of Sustainable Diatomite-Based Foams with a Micro-Macroporous Synergistic Structure

This study developed a foamed material with a synergistic microporous-macroporous structure through chemical foaming and high-pressure curing to better utilize the microporous properties of diatomaceous earth in building materials. The effects of different amounts of foaming agent, foam stabilizer, and CaO/SiO₂ on the mechanical properties and pore structure of the samples were investigated. The experimental results demonstrate that, under the influence of the foaming agent, the foam material has developed a multi-stage pore structure that integrates both macropores and micropores. This unique structure results in a dry density range of 467-670 kg/m³, thereby achieving significant material lightweighting. In addition, these macropores enhance the interaction between the micropores of diatomaceous earth and the external environment interface, thereby achieving a balance between the material's structural stability and functional properties. The material exhibits a porosity of 76.9% and a specific surface area of 42.9 m²/g, while maintaining a high compressive strength of 2.67 MPa. This work provides a technological pathway for the fabrication of multifunctional building materials that have both lightweight and eco-functional properties.