Thermal conductivity of heat treated mesoporous silica particles

The thermal conductivity of mesoporous silica particles prepared as fine powder and heat treated between 150 and 700 degrees C has been studied. Mesostructured silica particles of 30 nm diameter were synthesized through a derived sol-gel method in the presence of a cationic surfactant. The thermal conductivity was found to be ranged from 0.03 to 0.08 Wm(-1)K(-1) according to treatment and packing while the density, the porous volume and the specific surface area of materials varied between 350 and 700 kg/m(3), 0.01 and 1.21 cm(3)/g, and 10 and 420 m(2)/g, respectively. The analyses carried-out with X-ray diffraction, scanning electron microscopy, transmission electron microscopy, manometric adsorption/desorption of nitrogen, Fourier transform infrared spectrometry and solid-state nuclear magnetic resonance of Si-29 nucleus revealed that the thermal conductivity was modified in agreement with the structural changes subsequent to dehydration, decomposition of organic matter, loss of hydroxyl groups and sintering of silica particles. (C) 2014 Elsevier Inc. All rights reserved.