Wu Wen Bing, Xue Sun, Chen Jian Hua, Li Xiao
School of Chemical Engineering, Fuzhou University Fuzhou 350108 China
College of Chemistry, Chemical Engineering and Environment, Minnan Normal University Zhangzhou 363000 China.
RSC Adv. 2018 Dec 7;8(71):41003-41011. doi: 10.1039/c8ra06579a. eCollection 2018 Dec 4.
Membrane separation technologies have great promising potential for applications in several industries. Metal-organic frameworks (MOFs), for their large surface areas, low framework densities, transition-metal ions in the skeleton and high pore volumes relative to other porous matrices, have great potential for the removal of sulfur from gasoline with high efficiency. In the present study, a novel porous membrane adsorbent MIL-101(Cr)/SA was prepared by immobilizing MIL-101(Cr) onto sodium alginate (SA) matrix, which can combine the size/shape selectivity of MIL-101(Cr) with the processability and mechanical stability of SA polymer. The physico-chemical properties of MIL-101(Cr)/SA were investigated by FT-IR, SEM, BET, XRD and EDX methods. To investigate the effects of some important factors on the adsorption behavior for thiophene, a batch of experiments were performed by changing the concentration of porogen polyethylene glycol in the MIL-101(Cr)/SA, solution temperature, initial thiophene concentration and contact time. Meanwhile, benzothiophene, thiophene and 3-methyl thiophene were used to test the selectivity of MIL-101(Cr)/SA. The MIL-101(Cr)/SA showed an excellent uptake capacity of 671 mg g under the optimal adsorption conditions. Selectivity testing indicated that the uptake capacity of MIL-101(Cr)/SA follows the order of benzothiophene > thiophene > 3-methyl thiophene. Kinetics experiments indicated the pseudo-second-order model displayed good correlation with adsorption kinetics data. The Crank model showed that the intraparticle solute diffusion is the rate-controlling adsorption step. Regeneration experiment result shows that the prepared MIL-101(Cr)/SA has excellent adsorption and desorption efficiencies.
膜分离技术在多个行业具有巨大的应用潜力。金属有机框架材料（MOFs）因其具有较大的比表面积、较低的骨架密度、骨架中的过渡金属离子以及相对于其他多孔基质较高的孔体积，在高效去除汽油中的硫方面具有巨大潜力。在本研究中，通过将MIL-101（Cr）固定在海藻酸钠（SA）基质上制备了一种新型多孔膜吸附剂MIL-101（Cr）/SA，它可以将MIL-101（Cr）的尺寸/形状选择性与SA聚合物的可加工性和机械稳定性相结合。采用傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、比表面积分析仪（BET）、X射线衍射仪（XRD）和能谱仪（EDX）等方法对MIL-101（Cr）/SA的物理化学性质进行了研究。为了研究一些重要因素对噻吩吸附行为的影响，通过改变MIL-101（Cr）/SA中致孔剂聚乙二醇的浓度、溶液温度、初始噻吩浓度和接触时间进行了一系列实验。同时，使用苯并噻吩、噻吩和3-甲基噻吩来测试MIL-101（Cr）/SA的选择性。在最佳吸附条件下，MIL-101（Cr）/SA表现出671 mg/g的优异吸附容量。选择性测试表明，MIL-101（Cr）/SA的吸附容量顺序为苯并噻吩＞噻吩＞3-甲基噻吩。动力学实验表明，准二级模型与吸附动力学数据具有良好的相关性。Crank模型表明，颗粒内溶质扩散是吸附速率控制步骤。再生实验结果表明，制备的MIL-101（Cr）/SA具有优异的吸附和解吸效率。
