Synthesis of open-cell ceramic foam derived from geopolymer precursor via replica technique

This paper describes a facile and effective method for fabrication of open-cell ceramic foam derived from geopolymer precursor through replica technique. The polyurethane sponge method was applied using geopolymer mixture based on powder mixture of metakaolin/precipitated silica, potassium silica solution and fine chamotte filler. Accelerated solidification step at 60 degrees C for 30 min was performed to obtain dense structure with a good adhesion to the polymeric sponge. The effect of thermal treatment on mechanical and structural behavior of synthesized foams was investigated. X-ray diffraction (XRD) analysis indicated that no substantial differences in the content of crystalline Leucite - Potassium Aluminum Silicate phases appeared between thermally treated samples at 1100 degrees C, 1200 degrees C and 1300 degrees C. It has been revealed that compression strength of ceramic foams reached 0.85 +/- 0.11 MPa after the samples had been treated at 1300 degrees C. In addition, scanning electron microscopy (SEM) and X-ray micro computed tomography (mu-CT) confirmed uniform interconnected cellular structure with pore sizes between 1 and 2 mm resulting in an open porosity (epsilon(o)) of 78.88 vol%. (C) 2017 Elsevier B.V. All rights reserved.