添加剂对多孔陶瓷载体氧化铝涂层的影响

在以SB粉为原料,HNO3为解胶剂制得的稳定AlOOH溶胶中加入添加剂(PEG、PVA),对多孔陶瓷载体进行了表面涂层.考察了添加剂对AlOOH溶胶粘度的影响;BET法测定了AlOOH溶胶中加入添加剂后多孔陶瓷载体氧化铝涂层比表面积的变化;由SEM照片观察多孔陶瓷载体涂层前后表面和断面的形貌;超声波振荡检测了氧化铝涂层的附着牢固度.结果表明,在AlOOH溶胶中加入一定量的添加剂可以使溶胶的粘度增加,提高溶胶在载体表面的附着力;制备的多孔陶瓷载体氧化铝涂层均匀、牢固且比表面积增大.但加入过量的添加剂,会导致AlOOH溶胶胶凝化.

Influence of Additive on Al2O3 Coating of Porous Ceramic Substrate

Additives(PEG and PVA) were added into AlOOH sol which was prepared with SB powder as raw material and HNO3 as dispergator. The prepared AlOOH sol will be used as a coating modifier for the porous ceramic substrate. The influence of additive on AlOOH sol viscosity was investigated. The change of specific surface area of Al2O3 coating on porous ceramic substrate caused by the addition of additive to AlOOH sol was measured by BET method. The SEM photographs were used to study the shape of the surface and cross-section of ceramic substrate with Al2O3 coating. The fastness degree of coating was determined by ultrasonic vibration. The results show that additive with certain concentration leads to increase the AlOOH sol viscosity, however,too much additive causes sol gelation. The specific surface area of Al2O3 coating with additive increases at least 5 percent more than that of without additive. Moreover, on the porous ceramic substrate the Al2O3 coating prepared with additive is uniform and firm.