The influence of electrolytes on the diffusion properties of polystyrene colloidal particles in dense suspensions is measured by means of phase-modulated fiber optic low-coherence dynamic light scattering. In our experiments, both NaCl and BaCl2 are used as electrolytes. Experiment results show that the diffusion coefficients of the polystyrene colloidal particles increase with the increasing of ion concentration and ion valence when the concentration of electrolyte is below 0.01mol/L and the temperature keeps constant. The diffusion coefficients obtained experimentally show good agreement with the diffusion coefficients obtained by using the Stern model.%本文利用相位调制光纤低相干动态光散射装置，研究了不同物质量浓度下电解质(NaCl及BaCl2)对浓悬浮液中聚苯乙烯胶体颗粒扩散特性的影响.实验结果表明，当电解质浓度低于0.01 mol/L时，恒温条件下浓悬浮液中聚苯乙烯胶体颗粒扩散系数随电解质离子浓度以及离子化合价的增大而增大，实验测量得到的扩散系数与Stern模型所得到的扩散系数符合较好.
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