This study introduces an innovative approach to fabricating a poly ether ketone (PEEK)‐based thin‐film nanocomposite (TFN) nanofiltration membrane. Ultrafine polydopamine (PDA) modified zeolitic imidazolate framework‐8 (ZIF‐8) nanoparticles were integrated into the polyamide (PA) layer through a process of interfacial polymerization. The impacts of PDA@ZIF‐8 nanoparticle loading on composite membranes were examined, and their separation performances with different solvents and small molecular organics with various molecular weights and charges were evaluated. The PDA modification is credited with inducing a thinner, less crosslinked PA layer, culminating in the formation of a selective barrier that is both loose and ultra‐thin, improving the separation capabilities of membranes. The TFN‐3 membrane, with a 0.01 wt% loading of PDA@ZIF‐8 nanoparticles, emerged as a standout, demonstrating notably enhanced hydrophilicity. The pure water and organic solvent permeances through the TFN‐3 membrane were remarkably enhanced, with recorded values of 6.19 ± 0.26 L h−1 m−2 bar−1 for pure water and 3.44 ± 0.21 L h−1 m−2 bar−1 for methanol. Furthermore, the TFN‐3 membrane showcased impressive molecular retention in ethanol solutions for compounds with a molecular weight cut‐off (MWCO) of 464 g/mol. The PEEK‐based TFN‐3 membrane also exhibited exceptional creep resistance, ensuring consistent performance during long‐term testing. In a 5‐day ethanol separation test, the TFN‐3 membrane maintained a Rose Bengal (RB) retention rate exceeding 99%, underscoring its stability and reliability. The newly developed PEEK‐based TFN membrane not only promises robust solvent resistance and stability but also delivers efficient separation and purification capabilities. It holds great potential for offering effective and sustainable solutions across a spectrum of industries, particularly in pharmaceutical production and chemical processing, where the separation, recovery, and purification of solvents are paramount.
