Thermal insulating performance and compressive strength of ZSM-5 zeolite ceramics by cold sintering process

The cold sintering process, thermal insulating performance and compressive strength of ZSM-5 zeolite ceramics were investigated. Densification of ZSM-5 zeolite ceramics could be achieved by cold sintering process at 393 K under a pressure of 450 MPa for 0–60 min by adding 3 mol/L NaOH solution. X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) image, N 2 adsorption/ desorption measurements and fourier transform infrared (FT-IR) spectra demonstrated that zeolite framework was preserved without collapse of ordered microporous structure in the present ceramics. The thermal conductivity as low as 0.88 W/m·K was achieved together with a high compressive strength up to 315 MPa, which was attributed to the ordered microporous structure, amorphous phase and porosity in zeolite ceramics. The ZSM-5 zeolite ceramics prepared by cold sintering process could be expected as promising thermal insulating materials, since the low thermal conductivity was comparable with typical porous ceramics while the compressive strength was much higher than that of them.