含磺酸钠聚合物微凝胶的制备及对Cu(II)和Pb(II)的吸附

Preparation of Sodium Sulfonate-Containing Polymer Microgel for Cu(II)and Pb(II)Adsorption

采用回流-沉淀聚合制备了含磺酸钠聚合物微凝胶(SSPMg),通过扫描电子显微镜(SEM)、比表面及孔隙度分析(BET)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)等对其结构性能和化学组成进行了表征,并考察了SSPMg对Cu(II)和Pb(II)的吸附性能。结果表明,对苯乙烯磺酸钠占共聚单体总质量17.5%的微凝胶(SSPMg-4)在pH值=5时吸附效果最佳;吸附过程更符合准二级动力学和Langmuir等温吸附模型,以单分子层的化学吸附为主,包括络合、离子交换和静电吸附作用;吸附过程ΔG小于0、ΔH大于0,表现为常温下的自发吸热过程。298.15 K时,SSPMg-4对Cu(II)和Pb(II)的Langmuir理论最大吸附量分别达523.56 mg/g和568.18 mg/g。经过6次循环使用后,SSPMg-4对Cu(II)和Pb(II)的去除率保持在初始去除率的92%以上。

Sodium sulfonate-containing polymer microgel(SSPMg)was prepared by reflux-precipitation polymerization.The structure,properties and chemical composition of the obtained microgel were characterized by scanning electron microscope(SEM),surface area and porosity analyzer(BET),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).The adsorption performance of Cu(II)and Pb(II)by SSPMg were investigated.The results indicate that the adsorption effect of SSPMg-4 containing sodium p-styrenesulfonate accounting for 17.5%of the total mass of the comonomer,is the best at pH=5.The adsorption process is in accordance with pseudo second-order kinetic model and Langmuir isotherm model,indicating that the adsorption process of SSPMg for Cu(II)and Pb(II)is mainly attributed to the chemisorption of single-molecule layer.The adsorption mechanism includes complexation,ion exchange,and electrostatic adsorption.Adsorption processΔG is less than 0,ΔH is greater than 0,indicating that the adsorption process is a spontaneous endothermic process at normal temperature.At 298.15 K,the Langmuir theoretical maximum adsorption capacities of SSPMg-4 for Cu(II)and Pb(II)reaches 523.56 and 568.18 mg/g,respectively.After 6 cycles of recycling,the removal rate of Cu(II)and Pb(II)by SSPMg-4 remains above 92%of the initial.