Oxidation resistance and infrared emissivity of MoSi2@SiO2 particles prepared via TEOS hydrolysis self-assembly method

In order to avoid infrared emissivity deterioration of MoSi2 particles result from its high-temperature oxidation, a satisfactory electrostatic self-assembly process was presented to synthesize MoSi2@SiO2 particles. A thermally stable and transmitting infrared SiO2 shell was formed with tetraethyl orthosilicate (TEOS) as a precursor and tetrabutyl ammonium bromide (TBAB) as an electrostatic adsorbent after heat treatment at 1200 degrees C. The oxidation resistance, composition, micro-morphology and infrared emissivity of MoSi2@ SiO2 were studied using thermogravimetric analysis, X-ray diffraction, energy disperse spectroscopy, scanning electron microscopy, and ultravioletevisible near-IR spectrophotometer. The results demonstrated that MoSi2 particle was thoroughly encapsulated by a SiO2 glass shell, consequently, it exhibited great oxidation resistance compared with that of unencapsulated. More importantly, the emissivity of MoSi2@SiO2 particles had no obvious recession due to the intact encapsulation with TBAB. In addition, the electrostatic self-assembly mechanism of core-shell (MoSi2@SiO2) particles was discussed. (C) 2019 Elsevier B.V. All rights reserved.