The effects of ammonium polycarboxylate (AMP) on the dispersion of zinc oxide nanopowders were investigated in this study. Good dispersibility and stability in ZnO suspension with a dispersant content of 0.5 wt.% at pH 10 was observed by field emission scanning electron microscopy, and was confirmed by sedimentation experiments. The adsorption state of AMP on the surface of nano-sized ZnO powder was examined by Fourier transform infrared spectroscopy. For the ZnO nanopowders with various AMP amounts in the alkaline region, a maximum absolute zeta potential of 55.8 mV was measured at pH 10, which correlated well with the saturation amount of adsorbed AMP. Compacted varistor discs were prepared from the nano-origin ZnO powders before and after AMP absorption, showing sintered densities of 97.6% and 98.4%, respectively. The advantages of AMP were clearly seen in grain structuring, in addition to the enhanced densification and homogeneous microstructures for obtaining a high nonlinear coefficient.

本研究研究了聚羧酸铵（AMP）对氧化锌纳米粉体分散性的影响。通过场发射扫描电子显微镜观察到在pH 10时分散剂含量为0.5 wt。％的ZnO悬浮液中的良好分散性和稳定性，并通过沉降实验得到了证实。用傅立叶变换红外光谱法研究了AMP在纳米ZnO粉末表面的吸附状态。对于碱性区域中具有不同AMP量的ZnO纳米粉，在pH 10时测得的最大绝对Zeta电位为55.8 mV，这与吸附的AMP的饱和量密切相关。在AMP吸收之前和之后，用纳米ZnO粉末制备压敏电阻片，其烧结密度分别为97.6％和98.4％。