Molecular dynamics simulation of boric acid extraction by isobutanol/isooctanol liquid-liquid extraction

• This study systematically compares the extraction efficiency of boric acid using isobutanol and isooctanol under low pH conditions, revealing that isooctanol exhibits significantly superior performance. • Theoretical calculations demonstrate that isooctanol’s hydroxyl oxygen has a more negative electrostatic potential, enabling the formation of stronger and more stable hydrogen bonds with boric acid. • Molecular simulations show that isooctanol interacts with boric acid at shorter distances, with higher interaction energies and more hydrogen bonds of longer lifetimes than isobutanol. • The study identifies the hydrophobic alkyl group–enhanced van der Waals interactions as a key factor influencing extraction efficiency, offering microscopic insights for the rational design of high-performance extractants. Boric acid, a vital chemical in industries, agriculture, and high-tech fields, is primarily extracted from Salt Lake brines via liquid-liquid extraction. The efficiency differences between alcohols remain unclear. This study investigates boric acid extraction using isobutanol and isooctanol, combining experiments and theoretical calculations to reveal microscopic mechanisms. Experiments show that under low pH, multi-stage extraction significantly impacts efficiency, with isooctanol outperforming isobutanol. Computational results reveal that isooctanol’s hydroxyl oxygen has a more negative electrostatic potential, forming stronger, more stable hydrogen bonds with boric acid. Isooctanol also exhibits shorter interaction distances and higher interaction energy with boric acid compared to isobutanol. The study concludes that isooctanol’s superior performance is due to its ability to form more and longer-lived hydrogen bonds. This work provides new theoretical insights into boric acid extraction and aids in designing efficient extractants.