Fabrication of Functionalized MOFs Incorporated Mixed Matrix Hollow Fiber Membrane for Gas Separation

Haitao Zhu,Yiming Cao,Xingming Jie

doi:10.1155/2017/2548957

Abstract

The metal-organic framework (MOFs) of MIL-53 was functionalized by aminosilane grafting and then incorporated into Ultem®1000 polymer matrix to fabricate mixed matrix hollow fiber membrane (MMHFM) with high separation performance. SEM, XRD, and TGA were performed to characterize the functionalized MIL-53 and prepared MMHFM. The filler particles were embedded in membrane successfully and dispersed well in the polymer matrix. The incorporation of MOFs endowed MMHFM better thermal stability. Moreover, effects of solvent ratio in spinning dope, spinning condition, and testing temperature on gas separation performance of MMHFM were investigated. By optimizing dope composition, air gap distance, and bore fluid composition, MMHFM containing functionalized MIL-53 achieved excellent gas permeance and CO2/N2selectivity. The CO2permeance increased from 12.2 GPU for pure Ultem HFM to 30.9 GPU and the ideal CO2/N2selectivity was enhanced from 25.4 to 34.7 simultaneously. Additionally, gas permeance increased but the selectivity decreased with the temperature increase, which followed the solution-diffusion based transport mechanism.

Highlights

Membrane based gas separation and purification hold promise as energy-efficient technology if compared with traditional methods such as adsorption and cryogenic distillation [1,2,3,4]
In order to prepare asymmetric mixed matrix hollow fiber membrane (MMHFM) with optimal membrane structure and remarkable separation performance, we investigated the important factors including solvent/nonsolvent ratio in spinning dope solution, spinning condition, and testing temperature
More finger-like pores were generated in the outer region of MMHFM, which should be caused by instantaneous demixing with addition of metal-organic frameworks (MOFs) particles

Summary

Introduction

Membrane based gas separation and purification hold promise as energy-efficient technology if compared with traditional methods such as adsorption and cryogenic distillation [1,2,3,4]. MMM based on NH2-MIL-53 with improved structural feature and gas separation performance was synthesized by incorporating the filler particles in polyimide matrix. Other researchers have fabricated mixed matrix composite membrane by synthesizing MOFs continuous membrane on outer-side or inner-side of hollow fiber membrane to improve gas separation performance [23,24,25,26]. In NH2-MIL-53 incorporated MMM, the hydrogen bonding between the sulfone group of polysulfone and amine of MOFs enhanced compatibility at the polymer/filler interface [29]. The present work prepared functionalized MOFs by grafting aminosilane to improve the interfacial affinity between filler particles and polymer matrix. The –NH2 group on the functionalized MOFs could interact with carbonyl group of Ultem 1000 and the grafting alkyl chains enhanced the adhesion with polymer matrix. In order to prepare asymmetric MMHFM with optimal membrane structure and remarkable separation performance, we investigated the important factors including solvent/nonsolvent ratio in spinning dope solution, spinning condition (air gap distance and bore fluid composition), and testing temperature

Experimental

Mixed Matrix Hollow Fiber Membrane Preparation

Results and Discussion

Effect of Spinning Condition

Conclusion