Volume Phase Transition of Thermoresponsive Microgels Scrutinized by Dynamic Light Scattering and Turbidity : Correlations Depend on Microgel Homogeneity

Thermoresponsive microgels experience a volume phase transition triggered by temperature changes, a phenomenon often analyzed using dynamic light scattering to observe overall size alterations via the diffusion coefficient. However, local structural changes are typically assessed using more intricat...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 40(2024), 28 vom: 16. Juli, Seite 14515-14526
1. Verfasser: Otten, Marius (VerfasserIn)
Weitere Verfasser: Hildebrandt, Marco, Pfeffing, Ben, Voigt, Victoria Carina, Scheffold, Frank, Hellweg, Thomas, Karg, Matthias
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2024
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:Thermoresponsive microgels experience a volume phase transition triggered by temperature changes, a phenomenon often analyzed using dynamic light scattering to observe overall size alterations via the diffusion coefficient. However, local structural changes are typically assessed using more intricate and expensive techniques like small-angle neutron or X-ray scattering. In our research, we investigate the volume phase transition of poly-N-isopropylacrylamide (PNIPAM)-based microgels by employing a combination of temperature-dependent dynamic light scattering and simpler, faster, and more efficient attenuation measurements. We utilize attenuation at a fixed wavelength as a direct measure of dispersion turbidity, linking the absolute changes in hydrodynamic radius to the absolute changes in turbidity. This approach allows us to compare "classical" PNIPAM microgels from precipitation polymerization, charged copolymer microgels from precipitation copolymerization, and core-shell microgels from seeded precipitation polymerization. Our study includes a systematic analysis and comparison of 30 different microgels. By directly comparing data from dynamic light scattering and attenuation spectroscopy, we gain insights into structural heterogeneity and deviations from the established fuzzy sphere morphology. Furthermore, we demonstrate how turbidity data can be converted to swelling curves
Beschreibung:Date Revised 16.07.2024
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.4c01344