Real-time swelling-collapse kinetics of nanogels driven by XFEL pulses.

Autor: Dallari F; Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.; Department of Physics and Astronmy, University of Padua, Via Marzolo 8, 35131 Padova, Italy., Lokteva I; Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.; The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany., Möller J; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Roseker W; Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany., Goy C; Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany., Westermeier F; Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany., Boesenberg U; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Hallmann J; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Rodriguez-Fernandez A; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Scholz M; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Shayduk R; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Madsen A; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Grübel G; Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.; The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany.; European X-Ray Free-Electron Laser Facility, Holzkoppel 4, 22869 Schenefeld, Germany., Lehmkühler F; Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.; The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany.
Jazyk: angličtina
Zdroj: Science advances [Sci Adv] 2024 Apr 19; Vol. 10 (16), pp. eadm7876. Date of Electronic Publication: 2024 Apr 19.
DOI: 10.1126/sciadv.adm7876
Abstrakt: Stimuli-responsive polymers are an important class of materials with many applications in nanotechnology and drug delivery. The most prominent one is poly- N -isopropylacrylamide (PNIPAm). The characterization of the kinetics of its change after a temperature jump is still a lively research topic, especially at nanometer-length scales where it is not possible to rely on conventional microscopic techniques. Here, we measured in real time the collapse of a PNIPAm shell on silica nanoparticles with megahertz x-ray photon correlation spectroscopy at the European XFEL. We characterize the changes of the particles diffusion constant as a function of time and consequently local temperature on sub-microsecond timescales. We developed a phenomenological model to describe the observed data and extract the characteristic times associated to the swelling and collapse processes. Different from previous studies tracking the turbidity of PNIPAm dispersions and using laser heating, we find collapse times below microsecond timescales and two to three orders of magnitude slower swelling times.
Databáze: MEDLINE
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