Preparation of SiC nanoparticles coated by ZnC₂O₄

Sol-gel method was used to produce SiC particles coated with dihydrated zinc oxalate. The effect of main salt concentration and aging time on the coating was investigated. Dihydrated zinc acetate and oxalic acid are put into ethanol and heated to make ethanol solution of dihydrated zinc acetate and ethanol solution of oxalic acid respectively, with their mol ratio of 1:1.2 and Zn²⁺ concentration of 1.5mol·L^-1. SiC particles dispersed by ultrasonic for 5min and ethanol solution of oxalic acid are put into ethanol solution of dihydrated zinc acetate to make mixed solution. The mixed solution is stirred at high speed in a water-hath at 75°C and then gelatin is formed. SiC particles coated with zinc oxalate are obtained by aging for 4h and dryness. It is shown by means of HRTEM and EDS that SiC particles are dispersed in the gel of dihydrated zinc oxalate.