杯芳烃/还原氧化石墨烯纤维的制备及其选择性吸附性能

Preparation and selective adsorption of calixarene/reduced graphene oxide fibers

为提升杯芳烃纤维对Pt(Ⅱ)的平衡吸附量,依次通过酰胺化、还原法和静电纺丝法制备了杯芳烃/还原氧化石墨烯(CrGO)纤维。借助扫描电子显微镜、红外光谱仪、拉曼光谱仪和热重分析仪分析了纤维的结构与性能,并采用吸附实验研究了纤维的吸附选择性、吸附动力学及吸附等温模型。结果表明:CrGO纤维直径为(2±0.5)μm,具有褶皱的形貌,低水平的微观结构缺陷和良好的热稳定性;在Na(Ⅰ)、Hg(Ⅱ)共存时,CrGO纤维呈现出对Pt(Ⅱ)的选择性吸附能力,且符合假二级吸附动力学模型、Langmuir吸附等温模型;CrGO纤维的吸附行为主要归因于单分子层、化学型、吸热型、优惠型吸附;293 K温度下CrGO纤维在240 min时达到吸附平衡,平衡吸附量为113 mg/g,较杯芳烃聚酰亚胺纤维提升了303%。

In order to enhance the equilibrium adsorption capacity of calixarene fibers for Pt(Ⅱ),calixarene/reduced graphene oxide(CrGO)fibers were prepared through amidation,reduction and electrospinning.CrGO fibers were characterized by Fourier transform infrared spectroscopy,scanning electron microscopy,Raman spectrograph and thermogravimetric analyzer.The adsorption selectivity,adsorption kinetics and adsorption isotherm model of CrGO fibers were investigated.The results indicate that CrGO fibers with diameter of(2±0.5)μm possess some wrinkled morphology,low level of microstructure defects and a high thermal stability.In the presence of Na(I)and Hg(Ⅱ),CrGO fibers exhibit selective adsorption for Pt(Ⅱ),which fits with the pseudo second order adsorption kinetic model and Langmuir adsorption isothermal model.The adsorption behavior of CrGO fibers is mainly attributed to monolayer,chemical,endothermic and preferential adsorption.The equilibrium adsorption capacity of CrGO fibers reaches 113 mg/g at the temperature of 293 K for 240 min,which demonstrates an enhancement by 303%compared with calixarene polyimide fibers.