Removal of PFOS using amphiphilic cyclodextrins coated onto polypropylene
Author
Nielsen, Thomas Sandberg
Term
4. Term
Education
Publication year
2025
Submitted on
2025-06-02
Pages
116
Abstract
Denne afhandling undersøger, om amfifile cyklodextriner (ACD’er) kan belægge polypropylen (PP) og dermed bruges til at fjerne perfluorooctansulfonsyre (PFOS) fra vand. En serie β-cyklodextriner med varierende substitutionsgrad blev syntetiseret og karakteriseret (1H-NMR og massespektrometri). Opløsningsadfærd og partikel-/løsningsdannelse blev undersøgt i ethanol/vand-blandinger, og dynamisk lysspredning viste, at højere substitutionsgrad øger hydrofobicitet og kræver mere ethanol for at opnå opløsninger. PP-ark blev belagt fra disse blandinger; kontaktvinkelsmålinger viste, at ACD-belægninger reducerer PP’s hydrofobicitet, og at ACD’er med lavere substitutionsgrad giver mere hydrofile overflader. En adsorptionsundersøgelse med bisphenol A bekræftede værts–gæst-interaktioner, hvor optag øgedes med substitutionsgraden. Fjernelsesforsøg med PFOS validerede, at ACD-belagte PP-ark kan adsorbere PFOS. Kvantitativ 1H-NMR blev anvendt til at bestemme belægningsmængden og viste forskelle relateret til PP-arkenes arealtæthed. Samlet peger resultaterne på, at ACD-belagt PP er en lovende strategi til PFAS-fjernelse, og at belægnings- og adsorptionsadfærd kan styres via substitutionsgrad og opløsningsforhold.
This thesis examines whether amphiphilic cyclodextrins (ACDs) can be coated onto polypropylene (PP) to remove perfluorooctanesulfonic acid (PFOS) from water. A series of β-cyclodextrins with varying degrees of substitution were synthesized and characterized (1H-NMR and mass spectrometry). Their behavior in ethanol/water mixtures was studied, showing with dynamic light scattering that higher substitution increases hydrophobicity and shifts systems toward true solutions at higher ethanol content. PP sheets were coated from these mixtures; contact angle measurements showed that ACD coatings reduce PP hydrophobicity, with lower substitution producing more hydrophilic surfaces. An adsorption test using bisphenol A confirmed host–guest interactions and indicated that uptake increases with substitution degree. A PFOS removal experiment further validated adsorption by ACD-coated PP. Quantitative 1H-NMR was used to determine coating loadings and revealed differences linked to the areal density of the PP sheets. Overall, the results suggest ACD-coated PP is a promising approach for PFAS removal, with coating formation and adsorption performance tunable via substitution degree and solvent conditions.
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