High-Performance and Scalable Organosilicon Membranes for Energy-Efficient Alcohol Purification

The production of bio-alcohol is increasingly gaining international attention due to its potential as a viable alternative to fossil fuels and its ability to mitigate carbon dioxide emissions. However, the cost of bio-alcohol production is almost double that of fossil fuels, primarily because of the low yield of the purification process. Herein, a high-performance and scalable organosilicon membrane with high chain flexibility and controllable crosslinking density is developed for energy-efficient alcohol purification. The synthesized organosilicon membrane achieves an ultrahigh total flux (5.8 kg·m⁻²·h⁻¹) with a comparable separation factor (8.7) for ethanol/water separation, outperforming most state-of-the-art polymer-based membranes. Integrated experiments and molecular dynamics simulations confirm that the ultrafast alcohol permeation of the membrane originates from its high chain flexibility, large fractional free volume, and weak interactions between feed molecules and membranes. The universal applicability of the low-crosslinking mechanism for the formation of high-performance organosilicon membranes is also validated. Moreover, its high efficiency and scalability in membrane production, along with the stability of the casting solution, offer promising prospects for industrial applications.