The research team, headed by Professor Wan Yinhua from the Institute of Process Engineering (IPE) at the Chinese Academy of Sciences, has put forth a novel approach to enhance the performance of nanofiltration (NF) membranes. Their proposed post-modification strategy aims to achieve superior separation selectivity and robust fouling resistance. The key element of this strategy involves the use of ionic liquid (IL) to induce polyamide swelling rearrangement, thereby enabling effective polyelectrolyte deep grafting. These findings have been published in the prestigious AIChE Journal.
Nanofiltration membranes play a crucial role in various industrial processes, such as water purification and wastewater treatment. However, their performance is often limited by issues like inadequate selectivity and susceptibility to fouling. In order to overcome these challenges, Prof. Wan Yinhua’s team has developed a groundbreaking solution that holds immense potential for enhancing NF membrane efficiency.
Central to the proposed strategy is the utilization of an ionic liquid, a unique type of salt that remains in a liquid state even at room temperature. By introducing this IL, the researchers were able to induce a swelling rearrangement in the polyamide layer of the NF membrane. This restructuring process resulted in increased free volume and improved accessibility, thus creating an ideal environment for subsequent modifications.
Building upon the enhanced properties obtained through polyamide swelling, the researchers proceeded with polyelectrolyte deep grafting. Polyelectrolytes are materials composed of long, charged polymer chains, which can effectively interact with solutes during filtration processes. Through a carefully designed sequence of steps, the team achieved thorough penetration of polyelectrolytes into the modified polyamide structure, thereby significantly improving the membrane’s performance.
The advantages of this new approach are noteworthy. Firstly, the induced polyamide swelling rearrangement amplifies the separation selectivity of the NF membrane. This means that the membrane becomes more proficient in selectively filtering specific solutes while allowing others to pass through, leading to improved overall separation efficiency.
Secondly, the post-modification strategy enhances the fouling resistance of the NF membrane. Fouling, which refers to the accumulation of unwanted substances on the membrane surface, can ultimately diminish its effectiveness. By optimizing the polyamide structure and incorporating polyelectrolytes deep within the membrane, the researchers were able to mitigate fouling issues and prolong the membrane’s operational lifespan.
In conclusion, Prof. Wan Yinhua and his research team have introduced an innovative post-modification strategy that addresses crucial limitations of nanofiltration membranes. The use of ionic liquid-induced polyamide swelling rearrangement, coupled with polyelectrolyte deep grafting, demonstrates a promising path towards achieving superior separation selectivity and robust fouling resistance. These findings contribute valuable insights to the field of membrane technology, opening doors for advancements in various industries that heavily rely on efficient separation processes.
