P（AA-SSS-DMAPS）/MMT复合材料的制备及其对Pb2+的吸附行为

Synthesis of P（AA-SSS-DMAPS）/MMT composite and its application in Pb2+-adsorption behavior

采用原位聚合法,制备出了一种具有交联结构的P(AA-SSS-DMAPS)/MMT复合材料,通过FT-IR、XRD、TG和SEM对其结构进行了表征,并研究了P(AA-SSS-DMAPS)/MMT复合材料对水体中Pb^2+的吸附行为。试验结果发现,MMT的引入,不仅能够提高P(AA-SSS-DMAPS)/MMT复合材料的热稳定性能;而且还增大了复合材料的比表面积和吸附位点。在吸附试验中发现,当P(AA-SSS-DMAPS)/MMT复合材料用量为0.1 g、吸附时间为150 min、pH值=5.0、Pb^2+溶液的初始浓度为0.01 mol/L时,其对Pb^2+的饱和吸附容量为247.8 mg/g,且吸附过程更适合用Langmuir等温吸附模型描述。热力学研究发现,P(AA-SSS-DMAPS)/MMT复合材料对Pb^2+的吸附过程的ΔG<0,说明吸附过程可自发进行。

The P(AA-SSS-DMAPS)/MMT composite with cross-linked structure was prepared by in-situ polymerization. And FT-IR, XRD, TG and SEM were employed to characterize their structure and properties, and the adsorption behavior of Pb^2+ by P(AA-SSS-DMAPS)/MMT composites was studied. The results showed that the MMT was grafted onto the network of P(AA-SSS-DMAPS) and the composites with better heat stability was obtained. Moreover, due to the addition of MMT, it was found that P(AA-SSS-DMAPS)/MMT composite had larger specific surface area and adsorption sites. Under the conditions of an initial Pb^2+ concentration of 0.01 mol/L, pH of 5.0, contact time of 150 min and an amount of P(AA-SSS-DMAPS)/MMT composite of 0.1 g, the adsorbent capacity of P(AA-SSS-DMAPS)/MMT composite for Pb^2+ was found to be 247.8 mg/g and the adsorption system reached equilibrium. The adsorption of Pb^2+ conformed Langmuir isothermal adsorption model. And thermodynamic studies showed that the adsorption of Pb^2+ on the P(AA-SSS-DMAPS)/MMT composite was endothermic process, and due to ΔG<0, it indicated that the adsorption process could be carried out spontaneously.