Development of Thin-Film Nanocomposite Membranes with Metal-Organic Frameworks for PFAS Removal from Drinking Water

Abstract

This thesis investigates the development of metal–organic framework (MOF)-modified thin-film nanocomposite membranes for potential PFAS removal from drinking water. The work focuses on how MOF type and loading influence membrane morphology, surface properties, and hydraulic performance when incorporated into a polyamide selective layer.
Five MOFs, namely ZIF-8, ZIF-L, ZIF-94, NH₂-ZIF-8, and UiO-66-NH₂, were synthesized and evaluated as nanofillers in polyamide thin-film nanocomposite membranes prepared by interfacial polymerization on commercial polysulfone supports. The synthesized MOFs and prepared membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and water contact angle measurements. Preliminary pure water flux screening was used to identify hydraulically workable membrane formulations before further crossflow filtration testing.
The characterization results confirmed the successful synthesis of the selected MOFs and showed that MOF incorporation affected membrane morphology and wettability. ZIF-8-modified membranes displayed a relatively homogeneous morphology, whereas UiO-66-NH₂-modified membranes showed visible aggregation and defects. EDX analysis supported MOF incorporation through the detection of Zn in ZIF-based membranes and Zr in UiO-66-NH₂-modified membranes. Water contact angle measurements showed opposite wettability trends for the two main MOFs: ZIF-8 tended to increase the contact angle at higher loading, while UiO-66-NH₂ increased membrane hydrophilicity.
Filtration results showed that membrane performance depended strongly on MOF identity, loading, and selective-layer integrity. ZIF-L and NH₂-ZIF-8 resulted in no measurable flux during preliminary screening, while ZIF-94 showed very low flux. ZIF-8 and UiO-66-NH₂ were therefore selected for further evaluation. UiO-66-NH₂ at 0.1% (w/v) showed the highest initial water permeability among the PA-coated membranes, but this result should be interpreted with caution due to visible defects and aggregation. In contrast, ZIF-8 at 0.1% (w/v) showed the most balanced hydraulic performance, combining relatively high water permeability, low fouling factor, good hydraulic recovery, high PFAS filtration flux, and more homogeneous morphology.
Overall, this work demonstrates that MOF incorporation can improve the hydraulic performance of polyamide nanofiltration membranes when the MOF type and loading are properly selected. ZIF-8 at 0.1% (w/v) was identified as the most promising formulation in this study.

Popular Abstract

PFAS, or per- and polyfluoroalkyl substances, are man-made chemicals which have come to be referred to as "forever chemicals" due to the fact that these substances are very hard to degrade in the environment. These chemicals have become ubiquitous in many different types of manufactured items, including firefighting foam, non-stick cookware, waterproof clothing, and food wrapping. Due to the nature of PFAS, when released into the environment, PFAS can migrate through soil and groundwater until potentially reaching a source of drinking water. Therefore, the need exists for viable remediation options to remove PFAS from water so as to prevent further degradation to human health and the environment.
One area of research being explored for removing contaminants from water is through membrane filtration. Membrane filtration uses a semi-permeable membrane as a filter where pressure pushes water through the membrane allowing water molecules to pass through while preventing larger contaminants from passing through. Specifically, nanofiltration membranes are an attractive option because they allow smaller solutes to pass through while requiring significantly less force than reverse osmosis. One challenge however remains with nanofiltration membranes, specifically maintaining both high water flow rates and good contamination removal.
The objective of this thesis was to investigate if by incorporating Metal Organic Frameworks (MOFs) into the selective layer of a nanofiltration membrane would provide enhanced membrane performance. MOFs are highly ordered porous crystalline materials whose structure and chemistry can be controlled. As such, MOFs are an ideal additive material for developing new membranes with increased water flux and improved surface characteristics.
Several MOFs were synthesized and dispersed within polyamide-based thin film nanocomposites. Following synthesis and dispersion, all membranes were characterized based on their structural properties, surface characteristics, and water filtration behaviors. The data obtained indicated that the type of MOF used and its concentration greatly influenced the formation of the membrane and how freely water could pass through each respective membrane. Results indicate that some membranes developed using MOFs exhibited negligible or zero measurable water flux indicating that incorporation of MOFs does not inherently enhance membrane performance.
Of those membranes studied, the membrane containing 0.1 wt.% ZIF-8 demonstrated the most well-balanced performance regarding enhanced water permeability, reduced fouling propensity, excellent hydraulic recoveries upon cleaning, and higher-than-unmodified polyamide membrane filtration fluxes. A second MOF examined in this study, UiO-66-NH2, did demonstrate improvements in water transport; however, observable defects and particle aggregation in this particular system complicated interpretation of its performance relative to other systems.
In general terms, this thesis demonstrates that MOF-modified nanofiltration membranes possess significant promise for future applications involving PFAS contaminated water treatment; however, critical considerations should be given to selecting an appropriate MOF species, optimal loading levels, and effective dispersal methods.

• author: Putri, Nabila Aulia Laely
• supervisor: Mariona Battestini Vives; Beatriz Zornoza Encabo; Dalia Refaat
• organization: Chemical Engineering (M.Sc.Eng.)
• course: METM01 20261
• year: 2026
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: PFAS removal, Nanofiltration, Thin-film nanocomposite membrane, Metal–organic frameworks, Drinking water treatment, Membrane technology
• language: English
• id: 9247127
• date added to LUP: 2026-08-10 09:57:59
• date last changed: 2026-08-10 09:57:59