Experimental data for “Mechanistic Insights into Boron Fouling on Ion Exchange Membranes: An Experimental and Theoretical Study”

Experimental data is regarding the fouling mechanisms of boron species on ion exchange membranes during lithium enrichment from boron-containing solutions via electrodialysis. LiCl/BA solutions are employed as model foulants, in which the hybridization state of boron is precisely modulated by adjusting the pH and concentration to monitor the fouling processes of AEMs and CEMs. The zeta potential, particle size distribution and boron speciation of boric acid solutions was measured using a Zetasizer Nano (Malvern, UK) and Raman spectrometer (ROMAN, Thermo Fisher Scientific, USA). The transmission electron microscopy (TEM, JEM-F200, JEOL, Japan, 200kv) was employed to analyze and visualize the morphology of micro-scale boric acid aggregates on copper grids. Scanning electron microscopy (SEM, SU8010, Hitachi, Japan) and atomic force microscopy (AFM, Dimension Icon, Bruker, Germany) were used to obtain high-resolution images and the surface roughness of the fouled membranes. The surface chemical composition of IEMs was analyzed using Fourier-transform infrared spectroscopy (FT-IR, Nicolet iS5, Thermo Fisher, Waltham, USA). The FTIR data was processed in OMNIC 7.3 and the 2D-COS mapping was visualized by 2Dshige software (Shigeaki Morita, Japan, see in Text S5 for details about 2D-COS-FTIR analysis), with detailed procedure shown in Text S5. The surface zeta potential of IEMs in boric acid solutions under different conditions was measured using electrodynamic analyzer (SurPass 3, Anton Paar Trading Co., Ltd., Austria).