Effect of Composite Dispersants on the Stability of ZrO_2 Suspension

The composite dispersants which were composed of emulsifier OP (poiyoxyethylene Nonylphenol Ether) and CPB (hexadecylpyridinium bromide) were selected by the experiment to carry out the dispersion of the nano ZrO2 and the ZrO2 suspension was prepared,moreover,the effect of the stability of suspension caused by the ratio of the dosage of two constituents of the composite dispersants、pH value、and ion strength of the suspension were discussed. The results showed that the ZrO2 suspension which was added to the composite dispersants had better dispersion and stability.When the ratio of the dosage of OP and CPB was 1∶1,the zirconia powder in the suspension with 6% composite dispersants could be dispersed well,and the particle size of suspension was minimum in the pH=1.8,and the median diameter was 178 nm.It was also found that the isoelectric point of the suspension had shifted from pH=6 to pH=13,after the composite dispersants were added. In addition,the ion strength increased,the value of zeta potential would be reduced,and the particle size would be bigger,but the isoelectric point of ZrO2 suspensions was not affected by the ion strength,it was still maintained about 13.