Effects of surfactants on the microstructure and some intrinsic properties of porous building ceramics fabricated by gelcasting

Porous building ceramics were fabricated by gelcasting and the effects of surfactants on their microstructure and some intrinsic properties such as sound absorption and thermal conductivity were investigated. Preliminary tests on solubility in water, foaming capacity and foam stability of different surfactants were carried out to evaluate their foaming ability. Porous ceramic fabricated using an anionic ammonium lauryl sulphate surfactant with large foaming ability showed lower density, higher open and total porosities, and broad pore size distribution. Total porosities of three porous ceramics fabricated using different surfactants were found to be similar to that of the corresponding air volume fractions of the three foamed slurries. Sound absorption and thermal conductivity of the porous ceramics as construction tile were further characterized. Porous ceramic with higher porosity presented a higher value of sound absorption coefficients and lower thermal conductivity.