Bon, Chris Yeajoon Lee, Gwanwon Kim, Wonyeong Lee, Sungho Park, Sejoon 2026-02-26T04:30:04Z 2026-02-26T04:30:04Z 2026-02-26 2026-06 1383-5866 https://pubs.kist.re.kr/handle/201004/154367 Gas separation membranes offer an energy-efficient alternative to conventional separation technologies. However, achieving high permeability and selectivity simultaneously remains a challenge. In this work, we fabricate thin composite membranes composed of carbon nanotubes (CNTs), polyvinylidene fluoride (PVDF), and zeolitic imidazolate framework-8 (ZIF-8), and investigate the effect of heat treatment on their structural and transport properties. Thermal analysis, XRD, and XPS reveal that PVDF decomposition releases HF, which reacts with ZIF-8 to form ZnF2, inducing pore formation and altering the polymer structure. Gas permeation measurements indicate that ZIF-8 incorporation enhances overall permeability, while heat treatment induces a transition in transport mechanism from solution-diffusion to a mixed regime consistent with molecular sieving and Knudsen diffusion. For example, the H2 permeability of CNT/PVDF membrane increased by more than an order of magnitude, from 0.16 to 32.6 Barrer for CPZ73(330) while also increasing in selectivity against larger molecules. Unlike conventional mixed-matrix membranes where fillers remain inert, ZIF-8 acts as a reactive component that changes the polymer microstructure. Overall, this work demonstrates a scalable, single-step approach for generating tunable gas transport pathways and offers a general framework for thermally reactive polymer–MOF membranes for industrial separations. English Pergamon Press Ltd. Thermally induced transformation of ZIF-8 to ZnF2 in CNT/PVDF composite membranes for tunable porosity and gas transport Article 10.1016/j.seppur.2026.136959 1 Separation and Purification Technology, v.391 Separation and Purification Technology 391 Y scie scopus 001684472000003 2-s2.0-105029059683 Engineering, Chemical Engineering Article MIXED MATRIX MEMBRANES POLY(VINYLIDENE FLUORIDE) CARBON NANOTUBES PVDF SEPARATION NANOCRYSTALS DEGRADATION Gas separation membrane Mixed matrix membrane Carbon nanotubes PVDF ZIF-8 Thermal treatment