Stabilized homogeneous porous structure and pore type effects on the properties of lightweight kaolinite-based geopolymers

Characterization and Performance Evaluation of Metakaolin-Based Geopolymer Foams Obtained by Adding Palm Olein as the Foam Stabilizer

“…A linear regression analysis was employed to describe the effect of open porosity on the bulk density of geopolymer foams. Regression lines in Figure 10 showed a distinct negative correlation between the bulk density and open porosity of geopolymer foams, which is consistent with the finding in literature [ 5 ].…”

“…Due to their characteristics as both geopolymer and porous materials, geopolymer foams have been widely investigated by researchers recently. The properties of geopolymer foams are significantly influenced by their pore characteristics, such as porosity, pore types (closed or open), connectivity, and pore size distribution [ 3 , 4 , 5 , 6 ]. Generally, geopolymer foams with higher porosity possess lower compressive strength, thermal conductivity, and bulk density [ 5 ].…”

“…The properties of geopolymer foams are significantly influenced by their pore characteristics, such as porosity, pore types (closed or open), connectivity, and pore size distribution [ 3 , 4 , 5 , 6 ]. Generally, geopolymer foams with higher porosity possess lower compressive strength, thermal conductivity, and bulk density [ 5 ]. However, the effect of different pore types on the performance of geopolymer foams is inconsistent.…”

“…With elevated open porosity, the connectivity of isolated pores in the structure increases, forming irregular large open and connected pores [ 4 ]. Geopolymer foams having connected pore networks own high specific surface area and volume capacity, which make them hold significant advantages in terms of water and sound absorption, although the mechanical properties are slightly inferior [ 5 ]. In addition to the above factors, the pore size distribution significantly affects the performance of geopolymer foams [ 6 ].…”

“…Foam stabilizers can elevate the stability of foams by strengthening the molecular structure of the pore walls and reducing the surface tension of the mixture [ 3 ]. Some surfactants or stabilizing agents, such as sodium dodecyl sulfate (SDS) [ 28 , 29 ], sodium lauryl ether sulfate (SLES) [ 5 ], tween80 [ 30 ], and vegetable oils [ 17 , 27 , 31 ], are often used as foaming stabilizers to prepare geopolymer foams in combination with foaming agents [ 5 , 17 , 27 , 28 , 29 , 30 , 31 ]. Compared to those prepared with other foam stabilizers, geopolymer foams that are fabricated using vegetable oils have higher porosity [ 32 , 33 ].…”