甲基橙印迹磁性壳聚糖聚合物的制备及吸附特性

以通过溶胶-凝胶法自制的Fe₃O₄@壳聚糖（CTS）微球为载体，甲基橙（MO）为模板分子，采用水溶液聚合法制得磁性壳聚糖表面分子印迹聚合物（MMIPs）。通过SEM、XRD、FT-IR和VSM表征了MMIPs的结构和性能，并探究了其对MO的识别与选择性吸附特性。研究表明：与非印迹聚合物（NIMPs，饱和吸附量为20.56 mg/g）相比，在相同条件（pH值6.5、25℃）下，MMIPs对MO具有明显的特异性吸附能力，在60 min左右吸附饱和，饱和吸附量（Q_e）可达113.16 mg/g；MMIPs对MO的吸附符合Langmuir等温吸附模型和准二级吸附动力学模型；在其他干扰染料的存在下，MMIPs的选择性系数（K）最高可达2.85，对MO具有选择识别性；此外，吸附完成后MMIPs可在磁场作用下快速分离，解吸附后循环使用5次，吸附率均在90%以上。

Preparation and Adsorption of Methyl Orange Imprinted Magnetic Chitosan Polymer

Magnetic chitosan(Fe₃O₄@CTS) microspheres were prepared through sol-gel method firstly. Then, a novel, magnetic molecularly imprinted polymers(MMIPs) were synthesized by aqueous solution polymerization with Fe₃O₄@CTS as support and functional monomer and methyl orange as template molecules. Characterizations of the obtained MMIPs were achieved by SEM, XRD, FT-IR and VSM. Batch adsorption experiments were performed to investigate the adsorption conditions, selectivity and reusability of the adsorption of MO on MIMPs. The results showed that the maximum adsorption capacity was 113.16 mg/g and equilibrium adsorption was achieved around 60 min observed at pH value 6.5 and temperature 25℃, and the MMIPs had specific adsorption capacity for MO compared with the non-imprinted magnetic particles(NIMPs). Adsorption process could be well described by Langmuir adsorption isotherms and the kinetic data could be fitted with pseudo-second-order equation. Furthermore, the selectivity coefficient of MO and other dyes onto MMIPs indicated an overall preference with the maximum selectivity coefficient(K) of 2.85. Moreover, MMIPs could be separated by external magnet, which could be reused for 5 times with a high adsorption efficiency overall 90% after desorption.