Novel amino-beta cyclodextrin-based organic solvent nanofiltration membranes with fast and stable solvent transport

Abstract

To expand industrial utilizations, membranes with fast transport of organic solvents and precision molecular separation, along with strong chemical stability, have great potential for minimizing energy consumption in separation processes. In this study, novel amino-cyclodextrin organic solvent nanofiltration (OSN) membranes containing P84 polymer were successfully fabricated using amino-cyclodextrin and amino-5-guanidinopentanoic acid (DL-A) as monomers through a two-step green modification process. The resulting membranes exhibit high stability in harsh organic solvents, such as dimethylsulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP), with a weight loss of less than 5 % after 30 days of immersion. These membranes also demonstrate rapid solvent transport for both polar solvents, such as methanol (86.56 L m−2 h−1 bar−1), and nonpolar solvents, such as n-hexane (48.97 L m−2 h−1 bar−1), along with high dye rejections. Additionally, the membranes possess rigid nanopores structures and consistent rejections across different pressures and solute concentrations. Most importantly, the newly synthesized amino-cyclodextrin OSN membranes are capable of separating molecules based on their 3D structures, particularly those with relatively similar molecular weights. Comparing to those reported cyclodextrin-based membranes, the newly developed amino-cyclodextrin OSN membranes show significant improvements in permeance for both polar and nonpolar organic solvents, while maintaining comparable dye rejection capabilities. The combination of fast solvent transport, excellent chemical stability, and shape selectivity makes these membranes highly promising for high-performance molecular separation in various industrial applications.