Quantitative characterization and control mechanism of pore structure in geopolymer foams with addition of various surfactants

Pore structure control mechanism in geopolymer foams (GPFs) remains qualitatively understood, posing great challenges for GPF applications. In this study, by modelling of various pore structures with regular geometric patterns, total porosity, open porosity, pore size distribution, and pore deformation were quantitatively characterized. Then, we focused on slurry viscosity and surface tension as the two crucial parameters, and investigated their impacts on the evolution of pore structures. It was revealed that viscosity primarily influenced foam deformation and coalescence, ultimately affecting foaming height, sample appearance, and the occurrence of foam collapse. Slurry surface tension predominantly affected pores connectivity, low surface tension corresponded to highly interconnected pores, while higher values favored closed pores. Additionally, a simple prediction model that enables the estimation of pore structures and their distributions based on GPFs visual appearance and height was proposed. At last, the relationships between pore structure and macro-performance were analyzed.