{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T07:23:58Z","timestamp":1788938638007,"version":"build-2803163510"},"reference-count":48,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,6,17]],"date-time":"2025-06-17T00:00:00Z","timestamp":1750118400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Japan Society for the Promotion of Science (JSPS)","award":["23K04533"],"award-info":[{"award-number":["23K04533"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>The removal of per- and polyfluoroalkyl substances (PFAS) from global aquatic environments is an emerging issue. However, little attention has been paid to addressing accumulated PFAS through their removal. This study demonstrates the encapsulation of perfluoroalkyl carboxylic acids (PFCAs) within polymer microspheres that dissolve in supercritical carbon dioxide (scCO2). PFCAs were effectively captured by a hindered amine-supported monomer, 2,2,6,6-tetramethyl-4-piperidyl methacrylate (TPMA), in methanol (MeOH) through a simple acid-base reaction. The PFCA-loaded TPMA underwent dispersion polymerization in MeOH in the presence of poly(N-vinylpyrrolidone) (PVP) as a surfactant, producing microspheres with high monomer conversions. The microsphere size depended on the molecular weight and concentration of PVP, as well as the perfluoroalkyl chain length of the PFCAs. X-ray photoelectron spectroscopy (XPS) revealed that the perfluoroalkyl chains migrated from the interior to the surface of the microspheres when exposed to air. These surface perfluoroalkyl chains facilitated dissolution of the microspheres in scCO2, with cloud points observed under relatively mild conditions. These findings suggest the potential for managing PFCA-encapsulated microspheres in the scCO2 phase deep underground via CO2 sequestration.<\/jats:p>","DOI":"10.3390\/polym17121688","type":"journal-article","created":{"date-parts":[[2025,6,17]],"date-time":"2025-06-17T11:53:14Z","timestamp":1750161194000},"page":"1688","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Encapsulation of Perfluoroalkyl Carboxylic Acids (PFCAs) Within Polymer Microspheres for Storage in Supercritical Carbon Dioxide: A Strategy Using Dispersion Polymerization of PFCA-Loaded Monomers"],"prefix":"10.3390","volume":"17","author":[{"given":"Eri","family":"Yoshida","sequence":"first","affiliation":[{"name":"Department of Applied Chemistry and Life Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi 441-8580, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"166764","DOI":"10.1016\/j.scitotenv.2023.166764","article-title":"Physicochemical properties and interactions of perfluoroalkyl substances (PFAS)\u2014Challenges and opportunities in sensing and remediation","volume":"905","author":"Leung","year":"2023","journal-title":"Sci. Total Environ."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"127313","DOI":"10.1016\/j.colsurfa.2021.127313","article-title":"Role of chain length and electrolyte on the micellization of anionic fluorinated surfactants in water","volume":"628","author":"Kancharla","year":"2021","journal-title":"Colloids Surf. A"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3183","DOI":"10.1039\/D4SU00152D","article-title":"Addressing the persistence of per and poly- fluoroalkyl substances (PFAS): Current challenges and potential solutions","volume":"2","author":"Itumoh","year":"2024","journal-title":"RSC Sustain."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1038\/s41561-024-01402-8","article-title":"Underestimated burden of per- and polyfluoroalkyl substances in global surface waters and groundwaters","volume":"17","author":"Grunfeld","year":"2024","journal-title":"Nat. Geosci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"151003","DOI":"10.1016\/j.scitotenv.2021.151003","article-title":"Per- and polyfluoroalkyl substances in water and wastewater: A critical review of their global occurrence and distribution","volume":"809","author":"Kurwadkar","year":"2022","journal-title":"Sci. Total Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1038\/s41538-024-00319-1","article-title":"Comprehensive analysis of PFAS presence from environment to plate","volume":"8","author":"Dimitrakopoulou","year":"2024","journal-title":"npj Sci. Food."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1021\/acs.estlett.3c00119","article-title":"Horizontal and vertical distribution of perfluoroalkyl acids (PFAAs) in the water column of the Atlantic Ocean","volume":"10","author":"Savvidou","year":"2023","journal-title":"Environ. Sci. Technol. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"709","DOI":"10.1021\/acs.est.4c03652","article-title":"Nanomolar PFOA concentrations affect lipid membrane structure: Consequences for bioconcentration mechanisms","volume":"59","author":"Sobolewski","year":"2025","journal-title":"Environ. Sci. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"17039","DOI":"10.1021\/acs.est.2c04107","article-title":"Plasma PFOA and PFOS levels, DNA methylation, and blood lipid levels: A pilot study","volume":"56","author":"Cheng","year":"2022","journal-title":"Environ. Sci. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"862","DOI":"10.1021\/acs.estlett.4c00409","article-title":"Whale baleen to monitor per- and polyfluoroalkyl substances (PFAS) in marine environments","volume":"11","author":"Savoca","year":"2024","journal-title":"Environ. Sci. Technol. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"163302","DOI":"10.1016\/j.scitotenv.2023.163302","article-title":"Ecological characteristics impact PFAS concentrations in a U.S. North Atlantic food web","volume":"880","author":"Hedgespeth","year":"2023","journal-title":"Sci. Total Environ."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"606","DOI":"10.1002\/etc.4890","article-title":"DeWitt, J.C.; Christopher Lau, C.; Ng, C.; Smith, J.S.; Roberts, S.M. Per- and polyfluoroalkyl substance toxicity and human health review: Current state of knowledge and strategies for informing future research","volume":"40","author":"Fenton","year":"2021","journal-title":"Environ. Toxicol. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1038\/s41545-025-00457-3","article-title":"Technology status to treat PFAS-contaminated water and limiting factors for their effective full-scale application","volume":"8","author":"Tshangana","year":"2025","journal-title":"npj Clean Water"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"130834","DOI":"10.1016\/j.chemosphere.2021.130834","article-title":"Destruction of perfluorooctanesulfonate (PFOS) in a batch supercritical water oxidation reactor","volume":"279","author":"Pinkard","year":"2021","journal-title":"Chemosphere"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6647","DOI":"10.1021\/acs.est.2c00654","article-title":"Application of hydrothermal alkaline treatment for destruction of per- and polyfluoroalkyl substances in contaminated groundwater and soil","volume":"56","author":"Hao","year":"2022","journal-title":"Environ. Sci. Technol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"137743","DOI":"10.1016\/j.chemosphere.2023.137743","article-title":"Electrochemical degradation of PFOA and its common alternatives: Assessment of key parameters, roles of active species, and transformation pathway","volume":"315","author":"Zeidabadi","year":"2023","journal-title":"Chemosphere"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1021\/es902651g","article-title":"Sonochemical degradation of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in groundwater: Kinetic effects of matrix inorganics","volume":"44","author":"Cheng","year":"2010","journal-title":"Environ. Sci. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"105332","DOI":"10.1016\/j.jwpe.2024.105332","article-title":"Photo-oxidative\/reductive decomposition of perfluorooctanoic acid (PFOA) and its common alternatives: Mechanism and kinetic modeling","volume":"61","author":"Esfahani","year":"2024","journal-title":"J. Water Process Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"112979","DOI":"10.1016\/j.jece.2024.112979","article-title":"Plasma water treatment for PFAS: Study of degradation of perfluorinated substances and their byproducts by using cold atmospheric pressure plasma jet","volume":"12","author":"Topolovec","year":"2024","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"123770","DOI":"10.1016\/j.envpol.2024.123770","article-title":"Application of electron beam technology to decompose per-and polyfluoroalkyl substances in water","volume":"348","author":"Londhe","year":"2024","journal-title":"Environ. Pollut."},{"key":"ref_21","first-page":"11728","article-title":"Degradation of PFOA substitute: GenX (HFPO\u2212DA ammonium salt): Oxidation with UV\/persulfate or reduction with UV\/sulfite? Environ","volume":"52","author":"Bao","year":"2018","journal-title":"Sci. Technol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"21661","DOI":"10.1039\/D3NJ04290A","article-title":"Two-electron transfer photoreduction of methyl viologen and perfluorooctanoic acid mediated by flavin mononucleotide at colloidal titanium dioxide interfaces","volume":"47","author":"Saeed","year":"2023","journal-title":"New J. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2953","DOI":"10.1021\/acs.est.7b05912","article-title":"UV\/nitrilotriacetic acid process as a novel strategy for efficient photoreductive degradation of perfluorooctanesulfonate","volume":"52","author":"Sun","year":"2018","journal-title":"Environ. Sci. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1016\/j.synbio.2022.02.005","article-title":"Engineering and characterization of dehalogenase enzymes from Delftia acidovorans in bioremediation of perfluorinated compounds","volume":"7","author":"Harris","year":"2022","journal-title":"Synth. Syst. Biotechnol."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Broman, J., Ceja, A., Godoy, T., Rivera, D.R., Dionne, P., Schipper, J., Henkemeyer, S., Cegielski, S., Wong, G., and Kaur, A. (2021, January 11\u201314). Destruction of per- and polyfluoroalkyl substances (PFAS) via lacasse enzymatic degradation and electrochemical advanced oxidation. Proceedings of the 2021 Waste-management Education Research Conference (WERC), Las Cruces, NM, USA.","DOI":"10.1109\/WERC52047.2021.9477539"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1039\/D1EW00513H","article-title":"Emerging investigator series: Photocatalytic membrane reactors: Fundamentals and advances in preparation and application in wastewater treatment","volume":"8","author":"Ashley","year":"2022","journal-title":"Environ. Sci. Water Res. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"100043","DOI":"10.1016\/j.hazl.2021.100043","article-title":"Enhanced removal of perfluorooctane sulfonic acid and perfluorooctanoic acid via polyelectrolyte functionalized ultrafiltration membrane: Effects of membrane modification and water matrix","volume":"2","author":"Olimattel","year":"2021","journal-title":"J. Hazard. Mater. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5123","DOI":"10.1021\/acs.iecr.4c04024","article-title":"Mesoporous carbons and their modification with aliphatic quaternary amines for adsorption, thermal treatment, and preconcentration of perfluorooctanoic acid (PFOA)","volume":"64","author":"Shohel","year":"2025","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"83239","DOI":"10.1039\/C5RA16864C","article-title":"Mesoporous carbons: Recent advances in synthesis and typical applications","volume":"5","author":"Xin","year":"2015","journal-title":"RSC Adv."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3092","DOI":"10.1021\/acsestengg.4c00418","article-title":"Fast perfluorooctanoic acid (PFOA) removal with honeycomb-like nitrogen-doped carbon nanosheets: Mechanisms for the selective adsorption of PFOA over competing contaminants\/water matrix","volume":"4","author":"Chen","year":"2024","journal-title":"ACS ES&T Eng."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"136933","DOI":"10.1016\/j.chemosphere.2022.136933","article-title":"A juxtaposed review on adsorptive removal of PFAS by metal-organic frameworks (MOFs) with carbon-based materials, ion exchange resins, and polymer adsorbents","volume":"311","author":"Karbassiyazdi","year":"2023","journal-title":"Chemosphere"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3276","DOI":"10.1021\/acs.chemmater.1c00324","article-title":"Efficient removal of per- and polyfluoroalkyl substances from water with zirconium-based metal\u2212organic frameworks","volume":"33","author":"Li","year":"2021","journal-title":"Chem. Mater."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"12177","DOI":"10.1002\/ange.201905142","article-title":"Reduction of a tetrafluoroterephthalonitrile-\u03b2-cyclodextrin polymer to remove anionic micropollutants and perfluorinated alkyl substances from Water","volume":"131","author":"Klemes","year":"2019","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1240","DOI":"10.1021\/acsmaterialslett.0c00240","article-title":"Cyclodextrin polymers with nitrogen-containing tripodal crosslinkers for efficient pfas adsorption","volume":"2","author":"Yang","year":"2020","journal-title":"ACS Mater. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"160524","DOI":"10.1016\/j.scitotenv.2022.160524","article-title":"Modified linear solvation energy relationships for adsorption of perfluorocarboxylic acids by polystyrene microplastics","volume":"860","author":"Hatinoglu","year":"2023","journal-title":"Sci. Total Environ."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1783","DOI":"10.1039\/D3EW00208J","article-title":"Emerging investigator series: Impacts of aeration flow rates and bubble sizes on PFOA\/PFOS removal in electrocoagulation","volume":"9","author":"Mu","year":"2023","journal-title":"Environ. Sci. Water Res. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.watres.2017.04.057","article-title":"Removal efficiency of multiple poly-and perfluoroalkyl substances (PFASs) in drinking water using granular activated carbon (GAC) and anion exchange (AE) column tests","volume":"120","author":"McCleaf","year":"2017","journal-title":"Water Res."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"8269","DOI":"10.1038\/s41467-024-52690-y","article-title":"Fluoropolymer sorbent for efficient and selective capturing of per- and polyfluorinated compounds","volume":"15","author":"Yang","year":"2024","journal-title":"Nat. Commun."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3067","DOI":"10.1021\/ie980010x","article-title":"Solubility of homopolymers and copolymers in carbon dioxide","volume":"37","author":"Cao","year":"1998","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1509","DOI":"10.1063\/1.555991","article-title":"A new equation of state for carbon dioxide covering the fluid region from the triple-point temperature to 1100 K at pressures up to 800 MPa","volume":"25","author":"Span","year":"1996","journal-title":"J. Phys. Chem. Ref. Data"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1080\/10408390500526514","article-title":"Supercritical CO2 extraction of oilseeds: Review of kinetic and equilibrium models","volume":"46","author":"Valle","year":"2006","journal-title":"Crit. Rev. Food Sci. Nutr."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"272","DOI":"10.1016\/j.jcou.2016.08.002","article-title":"An industrial scale multiple supercritical carbon dioxide apparatus and its eco-friendly dyeing production","volume":"16","author":"Zheng","year":"2016","journal-title":"J. CO2 Util."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"105645","DOI":"10.1016\/j.supflu.2022.105645","article-title":"Production of biopharmaceutical dried-powders using supercritical CO2 technology","volume":"187","author":"Ryan","year":"2022","journal-title":"J. Supercrit. Fluids"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.matlet.2016.07.081","article-title":"Fabrication and characterization of nano-cellulose aerogels via supercritical CO2 drying technology","volume":"183","author":"Wang","year":"2016","journal-title":"Mater. Lett."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1295\/polymj.22.759","article-title":"Preparation of monodispersed poly(methyl methacrylate)particle in the size of micron range","volume":"22","author":"Kobayashi","year":"1990","journal-title":"Polym. J."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"8760","DOI":"10.1021\/acs.est.3c01220","article-title":"Identifying unknown fluorine-containing compounds in environmental samples using 19F NMR and spectral database matching","volume":"57","author":"Gauthier","year":"2023","journal-title":"Environ. Sci. Technol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"6344","DOI":"10.1021\/la049519p","article-title":"The outermost atomic layer of thin films of fluorinated polymethacrylates","volume":"20","author":"Ming","year":"2004","journal-title":"Langmuir"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1007\/s00396-011-2570-1","article-title":"Preparation of micro- and nanospheres with superamphiphobic surfaces","volume":"290","author":"Yoshida","year":"2012","journal-title":"Colloid Polym. Sci."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/17\/12\/1688\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:53:56Z","timestamp":1760032436000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/17\/12\/1688"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,17]]},"references-count":48,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["polym17121688"],"URL":"https:\/\/doi.org\/10.3390\/polym17121688","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,17]]}}}