ZnO-Al2O3混合粉体水基悬浮液性能的研究

通过Zeta电位、粘度、沉降等测试，研究了添加剂含量、pH值、固含量和球磨时间对ZnO-Al₂O₃混合粉体水基悬浮液的稳定性、流动性等的影响.实验结果表明：当pH值为9左右，聚丙烯酸添加质量分数为0.20%时，悬浮液粘度最低、稳定性最好.可制得固相体积分数55%的悬浮液.聚乙二醇添加量的增加，使悬浮液粘度增大、稳定性下降.该实验条件下，球磨时间以40h为佳.

Study on Dispersion Behavior of ZnO-Al2O3 Powders Aqueous Suspension

The stability and fluidity of ZnO-Al₂O₃ mixed powders suspension in aqueous solution adding with polyacrylic acid and polyethylene glycol were investigated. The Zeta potential of ZnO and Al₂O₃ were measured respectively in absence and presence of polyacrylic acid and polyethylene glycol. The influences of milling time, pH value, mass fraction of the additive and solid volume fraction on the stability and fluidity of ZnO-Al₂O₃ powders aqueous suspension were investigated by experiments of viscosity and sedimentation etc. It is noted that ZnO and Al₂O₃ powders have absolute value of zeta potential bigger than 45mV in pH value from 8 to 10.3 with adding polyacrylic acid. It is found that the suspension has the lowest viscosity and the best stability when the pH value is around 9 and the additive amount of polyacrylic acid is about 0.2wt%, in which the 55vol% solids content of slurry is obtained with the apparent viscosity less than 400mPa·s. The saturation absorption amount of polyacrylic acid for ZnO-Al₂O₃ mixed powders could be 0.2wt% in which the apparent viscosity is lower and the suspension stability is good in the pH range from 9 to 10.3. With the additive amount of polyethylene glycol increasing, the viscosity of suspension increase and the stability of suspension decease. The optimized milling time is 40h.