Séminaire

Mardi 14 Octobre 2025 à 11h00.

Fragmentation, Dynamics, and Function: Tailoring Particles with Light

Anna ZIEFUSS
(Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany)

Salle de séminaires Lippmann

Invité(e) par
David AMANS

présentera en 1 heure :

''Laser-based synthesis and processing of colloids (LSPC) has matured into a versatile technology for producing ultrapure nanoparticles across metals, oxides, and semiconductors. Among its variants, microparticle laser fragmentation in liquids (MPLFL) is particularly promising, as it combines the scalability of microparticle feedstocks with the size-control capabilities of nanoparticle fragmentation.[1] Yet, the fundamental mechanisms and energy balance of MP-LFL have remained unclear.
Here, we investigate MP-LFL with single-pulse, single-particle precision to quantify absorbed energy and fragmentation dynamics. Pump–probe microscopy reveals that photomechanical stress waves and cavitation are the primary processes, while photothermal contributions are secondary. Although only ≈1% of the absorbed energy directly contributes to new nanoparticle surface formation, the overall eOiciency exceeds that of laser ablation in liquids by more than an order of magnitude. [1]
The resulting fully inorganic gold nanoclusters (less than 3 nm) exhibit size- and surface-chargedependent fluorescence. Ultrasmall clusters are governed by surface-state emission, while larger ones display core-based luminescence.[2] The emission intensity can be tuned by pH, and alloying with platinum induces quenching and red-shifts, underlining the key role of surface charge and composition in defining optical properties.[2,3]
By linking fragmentation energetics with controllable optoelectronic behavior, this work establishes MP-LFL as an energy-eOicient and scalable route for producing ligand-free nanoclusters. The ability to tailor fluorescence and stability opens perspectives for applications in catalysis, sensing, and photonics.

Reference:
[1] M. Spellauge, M. Tack, R. Streubel, Ma6hias Miertz, S. Reichenberger, S. Barcikowski, H. P. Huber, and A. R. Ziefuss: SMALL, 2023, 19, 10, 2206485
[2] A. R. Ziefuss, T. Steenbock, D. Benner, A. Plech, J. Gö6licher, M. Teubner, B. Grimm-LebsanU, C. Rehbock, C. Comby-Zerbino, R. Antoine, D. Amans, I. Chakraborty, G. Bester, M. Nachev, B. Sures, M. Rübhausen, W. J. Parak, S. Barcikowski: Advanced Materials, 2021, 33, 31, 21015493,
[3] A. R. Ziefuss, M. Willeke, M. Miertz, A. Heinemann, C. Rehbock, ChemPhysChem, 2022, 6,
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