Fabrication of polyacrylonitrile-Li1.6Mn1.6O4 composite nanofiber flat-sheet membranes via electrospinning method as effective adsorbents for Li+ recovery from salt-lake brine

• Published in: Separation and purification technology 2022-02, Vol.284, p.120242, Article 120242
• Main Authors: Ding, Kaiyue, Zhu, Guiru, Song, Chenghao, Wang, Qi, Wang, Lin, Wang, Ziqi, Meng, Chunxia, Gao, Congjie
• Format: Article
• Language: English
• Subjects: Brine; Electrospinning; Flat-sheet membranes; Ion sieve; Nanofiber; Polyacrylonitrile
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2021.120242

[Display omitted] •The PAN-H1.6Mn1.6O4 composite nanofiber membranes were prepared by electrospinning.•Nanofiber membrane has higher Li+ adsorption capacity than that of dense membrane.•Nanofiber membrane shows high selectivity and Qe for Li+ in salt-lake brine.•Li+ can be enriched by dynamic adsorption via the column packed with membrane. In this paper, polyacrylonitrile (PAN) as the binder and Li1.6Mn1.6O4 as the powder were used to prepare the composite nanofiber flat-sheet membrane-type adsorbent (ESNM-H) via the electrospinning method. The influence factor on membrane adsorption capacity for Li+ were investigated, such as the concentration of PAN, precursor content, and membrane thickness. When the content of PAN and Li1.6Mn1.6O4 were 10 wt% and 18 wt%, respectively, the equilibrium adsorption capacity for Li+ on ESNM-H with the thickness of 164 ± 4 μm was 1328 mg/m2, and the actual adsorption capacity of powder H1.6Mn1.6O4 incorporated in the nanofiber membrane remained 92% of the unsupported powder. In the artificial salt-lake brine, the adsorption selectivity of ESNM-H for Li+ was higher to other interfering ions (Na+, Ca2+, K+ and Mg2+). After eight cycles, the adsorption capacity of ESNM-H decreased by 8%. The ESNM-H exhibited the better long-term stability. The ESNM-H packed column was enriched with Li+ from 100 mg/L to 726 mg/L after ten consecutive dynamic adsorption–desorption cycles. The overall results show that the composite nanofiber flat-sheet membrane-type adsorbent fabricated via the electrospinning method has potential applications and recyclability in adsorbing Li+ from salt-lake brine.