微米级SPS微球的制备及对Pb2+的快速吸附

Preparation of Micro-sized Sulfonated Polystyrene Microspheres and Rapid Adsorption of Pb2+

摘要:

以苯乙烯为单体，运用分散聚合法制备微米级聚苯乙烯微球（PS），通过浓硫酸改性制备微米级磺化聚苯乙烯微球（SPS），并应用于吸附重金属Pb2+。通过SEM、FIRT、TG、XRD、XPS、元素分析对制备的PS微球与SPS微球进行结构表征；同时研究了浓硫酸改性过程中PS微球与浓硫酸料液比（g:mL）、磺化时间对微球磺化度的影响；并探讨了吸附时间、溶液pH、底物初始浓度对SPS微球吸附Pb2+的影响以及研究了SPS微球的吸附稳定性和吸附Pb2+后的脱附性能。结果表明：制备的PS微球粒径均一，平均粒径大小为1.2 μm。在40 ℃、反应48 h、料液比为1:40 g/mL条件下进行磺酸化改性，得到具有良好水溶性、单分散性、粒径均一的SPS微球，平均粒径大小为1.4 μm，磺化度为0.560±0.01 mmol/g；SPS微球吸附和脱附Pb2+平衡时间分别为5 min、1 min，脱附率达99.81%，循环4次使用后，吸附性能保持不变。

Abstract:

Micron-sized polystyrene (PS) microspheres were prepared via dispersion polymerization using styrene as the monomer. Micron-sized sulfonated polystyrene (SPS) microspheres were produced via modification with concentrated sulfuric acid before being applied to adsorb heavy metal Pb2+. The structural characterization of PS and SPS microspheres were performed by SEM, FIRT, TG, XRD, XPS and elemental analysis. In the meantime, the effect of the ratio of PS microspheres to concentrated sulfuric acid (g : mL), and the sulfonation degree of microspheres as a function of sulfonation time, were also studied. Moreover, the effects of adsorption time, solution pH and initial substrate concentration on the adsorption of Pb2+ on SPS microspheres were investigated, along with the adsorption stability and desorption properties of SPS microspheres. The results showed that the prepared PS microspheres had uniform particle size and an average particle size of 1.2 μm. The sulfonation modification performed at 40 ℃ for 48 h and a solid-to-liquid ratio of 1:40 (g : mL yielded SPS microspheres with good water solubility, monodispersity and uniform particle size, along with an average particle size of 1.4 μm and degree of sulfonation of 0.560±0.01 mmol/g. The adsorption and desorption equilibrium times for Pb2+-SPS microspheres were 5 min and 1 min, respectively, with a desorption rate of 99.81% and unchanged adsorption performance after four cycles.