This study presents a versatile method for the production of silica foams with different particle concentration that have wet foam stability above 80%. The foams were produced by using a direct foaming method with inorganic particles (SiO2) and Hexylamine, a short chain amphiphile, at a specific range of pH through the in-situ hydrophobization mechanism. The wet foams were finally dried at room temperature and then sintered, exhibiting free energy of 2.5 x 10(8) kTs and pressure difference of 0.8 mPa for colloidal SiO2 particles with average diameter of 3.5 mu m. Microstructural examinations of the wet and the sintered foams were performed through the use of optical and scanning electron microscopy where the decrease in pore size was observed to be related to an increase in particle concentration among the interconnected pores.

Keywords: Porous ceramics; Direct foaming; Adsorption free energy; Laplace pressure; Wet foam stability; Ostwald ripening