Electrospun cationic nanofiber membranes for adsorption and determination of Cr(vi) in aqueous solution: adsorption characteristics and discoloration mechanisms

Run Fang; Bing-Chiuan Shiu; Yuansong Ye; Yuchi Zhang; Hanyu Xue; Ching-Wen Lou; Jia-Horng Lin

doi:10.1039/d1ra05917c

Electrospun cationic nanofiber membranes for adsorption and determination of Cr(vi) in aqueous solution: adsorption characteristics and discoloration mechanisms

RSC Adv. 2021 Sep 27;11(50):31795-31806. doi: 10.1039/d1ra05917c. eCollection 2021 Sep 21.

Authors

Run Fang^{1

2}, Bing-Chiuan Shiu^{1

2}, Yuansong Ye^{1

2}, Yuchi Zhang^{1

2}, Hanyu Xue^{1

2}, Ching-Wen Lou^{1

3

4

5

6}, Jia-Horng Lin^{1

3

4

7

5}

Affiliations

¹ Department of Material and Chemical Engineering, Minjiang University Fuzhou 350108 China jhlin@fcu.edu.tw readfung@163.com +886 4 24518661 +86 591 83761630.
² Fujian Engineering and Research Center of New Chinese Lacquer Materials Fuzhou 350108 China.
³ Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textile Science and Engineering, Tiangong University Tianjin 300387 China.
⁴ Advanced Medical Care and Protection Technology Research Center, College of Textile and Clothing, Qingdao University Shandong 266071 China.
⁵ School of Chinese Medicine, China Medical University Taichung 40402 Taiwan China.
⁶ Department of Bioinformatics and Medical Engineering, Asia University Taichung 41354 Taiwan China.
⁷ Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University Taichung 40724 Taiwan China.

Abstract

In this study, a novel cationic nanofiber membrane with various functional groups, good structural stability, and high adsorption capacity of Cr(vi) is presented. This nanofiber membrane is prepared by electrospinning a mixed aqueous solution of a cationic polycondensate (CP) and polyvinyl alcohol (PVA). With the aid of PVA, CP can be smoothly electrospun without using any organic solvents, and the cross-linking between CP and PVA improves the stability of membrane in acidic solution. Chemical and morphology characterization reveals that the CP/PVA membrane is composed of interwoven nanofibers that contain numerous cationic groups. Due to its high cationicity and hydrophilicity, the CP/PVA membrane shows great affinity for HCr₂O₇ ^- and Cr₂O₇ ^2-. Adsorption experiments indicate that the CP/PVA membrane can remove Cr(vi) from simulated wastewater rapidly and efficiently in both batch and continuous mode. Besides, the presence of most coexisting ions will not interfere with the adsorption. Due to the redox reaction between the CP/PVA membrane and adsorbed Cr(vi), the CP/PVA membrane exhibits distinct color change after Cr(vi) adsorption and the discoloration is highly dependent on the adsorption amount. Therefore, in addition to serving as a highly efficient adsorbent, the CP/PVA membrane is also expected to be a convenient and low-cost method for semi-quantitative determination of Cr(vi) in wastewater.