The objective of this study is to optimize the process parameters for preparing polystyrene (PS) PM2.5 particles by supercritical antisolvent (SAS) method. Toluene was selected as the solvent and supercritical carbon dioxide (SC-CO₂) was used as the antisolvent. The Box–Behnken design-response surface method was applied to investigate the effect of crystallizer pressure, PS massic concentration, flow ratio of CO₂/solution and crystallizer temperature on the size and the distribution of PS particles, systematically. It is found that crystallizer temperature is the most significant variable on the size and the distribution of PS particles, followed by flow ratio of CO₂/solution and PS massic concentration, and crystallizer pressure is the slightest significant factor. The particle size increases with the increase of crystallizer temperature. The optimum conditions are obtained as crystallizer pressure 9.8 MPa, PS massic concentration 1.6 wt%, flow ratio of CO₂/solution 140 g/g and crystallizer temperature 309 K. Under these conditions, the PS particle with the size of 2.78 μm and a narrow size distribution has been prepared, meeting PM2.5 standard aerosols. The results suggest that it is feasible to produce PM2.5 standard aerosols by SAS.

这项研究的目的是优化通过超临界抗溶剂（SAS）方法制备聚苯乙烯（PS）PM2.5颗粒的工艺参数。选择甲苯作为溶剂，并使用超临界二氧化碳（SC-CO ₂）作为抗溶剂。运用Box–Behnken设计响应面方法系统地研究了结晶器压力，PS质量浓度，CO ₂ /溶液的流量比和结晶器温度对PS颗粒尺寸和分布的影响。发现结晶器温度是影响PS颗粒尺寸和分布的最大变量，其次是CO _2的流量比/溶液和PS质量浓度，以及结晶器压力是最小的重要因素。粒度随着结晶器温度的升高而增加。获得了最佳条件，即结晶器压力9.8 MPa，PS质量浓度1.6 wt％，CO ₂ /溶液的流量比140 g / g和结晶器温度309K。在这些条件下，粒径为2.78μm的PS颗粒已准备好窄尺寸分布，符合PM2.5标准气雾剂。结果表明，通过SAS生产PM2.5标准气溶胶是可行的。