“Induced-Fit Suction” effect: a booster for biofuel storage and separation

Abstract

Target-response deformation has provided a wide variety of possibilities for selective molecular separation. In this report, both experimental and theoretical methods were used to demonstrate how fine-tuning the amphiphilicity of ZIF-7 can induce an alcohol-based target-response deformation. A step-by-step simulation of dynamic adsorption revealed that ZIF-7-NH₂ can successfully align alcohol molecules to facilitate selective adsorption, while the benzene rings in ZIF-7-NH₂ were induced to flip over and maintain the open-gate conformation. As a result, ZIF-7-NH₂ with an amino mole ratio of 10% achieved an ideal n-butanol/water selectivity of 40, and also the highest n-butanol uptake of 4.33 mmol g⁻¹ from 5 wt% n-butanol aqueous solution under ambient conditions. Therefore, a new mechanism of “Induced-Fit Suction” (IFS) that we propose provides a promising new strategy for biofuel separation.