LIVIVO - Das Suchportal für Lebenswissenschaften

switch to English language
Erweiterte Suche

Suchergebnis

Treffer 1 - 10 von insgesamt 34

Suchoptionen

  1. Artikel ; Online: In situ observation of coalescence of nuclei in colloidal crystal-crystal transitions.

    Peng, Yi / Li, Wei / Still, Tim / Yodh, Arjun G / Han, Yilong

    Nature communications

    2023  Band 14, Heft 1, Seite(n) 4905

    Abstract: Coalescence of nuclei in phase transitions significantly influences the transition rate and the properties of product materials, but these processes occur rapidly and are difficult to observe at the microscopic scale. Here, we directly image the ... ...

    Abstract Coalescence of nuclei in phase transitions significantly influences the transition rate and the properties of product materials, but these processes occur rapidly and are difficult to observe at the microscopic scale. Here, we directly image the coalescence of nuclei with single particle resolution during the crystal-crystal transition from a multilayer square to triangular lattices. The coalescence process exhibits three similar stages across a variety of scenarios: coupled growth of two nuclei, their attachment, and relaxation of the coalesced nucleus. The kinetics vary with nucleus size, interface, and lattice orientation; the kinetics include acceleration of nucleus growth, small nucleus liquefaction, and generation/annihilation of defects. Related mechanisms, such as strain induced by nucleus growth and the lower energy of liquid-crystal versus crystal-crystal interfaces, appear to be common to both atomic and colloidal crystals.
    Sprache Englisch
    Erscheinungsdatum 2023-08-15
    Erscheinungsland England
    Dokumenttyp Journal Article
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-023-40627-w
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

  2. Artikel: Origin of the Acoustic Bandgaps in Hypersonic Colloidal Phononics: The Role of the Elastic Impedance

    Cang, Yu / Sainidou, Rebecca / Rembert, Pascal / Magnabosco, Giulia / Still, Tim / Vogel, Nicolas / Graczykowski, Bartlomiej / Fytas, George

    Journal of physical chemistry. 2022 Aug. 23, v. 126, no. 34

    2022  

    Abstract: How phonons propagate in nanostructures determines the flow of elastic and thermal energy in dielectric materials. However, a reliable theoretical prediction of the phonon dispersion relation requires experimental verification both near to and far from ... ...

    Abstract How phonons propagate in nanostructures determines the flow of elastic and thermal energy in dielectric materials. However, a reliable theoretical prediction of the phonon dispersion relation requires experimental verification both near to and far from the Brillouin zone of the nanostructure. We report on the experimental hypersonic phonon dispersion of hard (SiO₂) and soft (polymer) fcc colloidal crystals infiltrated in liquid polydimethylsiloxane with different elastic impedance contrast using Brillouin light spectroscopy. We discuss the distinct differences with first-principles full elastodynamic calculations involving a multiple-scattering theory. Interparticle contacts strongly impact the long-wavelength speed of sound and the nature of the particle vibration resonance-induced hybridization hypersonic bandgap. The absence of the order-induced Bragg bandgap in SiO₂ and its presence in soft opals cannot be fully accounted for by the theory, limiting its predictive power. Bridging the elasticity of the two colloidal crystals with suitable SiO₂ core–shell (polymer) particles reveals an unprecedented crossover behavior in the dispersion relation. In view of many conversational parameters, the control tuning of phonon propagation in soft matter-based hypersonic phononics remains challenging.
    Schlagwörter acoustics ; hybridization ; liquids ; nanomaterials ; physical chemistry ; polydimethylsiloxane ; prediction ; spectroscopy ; thermal energy ; vibration
    Sprache Englisch
    Erscheinungsverlauf 2022-0823
    Umfang p. 6575-6584.
    Erscheinungsort American Chemical Society
    Dokumenttyp Artikel
    ISSN 1520-5207
    DOI 10.1021/acs.jpcb.2c03923
    Datenquelle NAL Katalog (AGRICOLA)

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  3. Artikel ; Online: Origin of the Acoustic Bandgaps in Hypersonic Colloidal Phononics: The Role of the Elastic Impedance.

    Cang, Yu / Sainidou, Rebecca / Rembert, Pascal / Magnabosco, Giulia / Still, Tim / Vogel, Nicolas / Graczykowski, Bartlomiej / Fytas, George

    The journal of physical chemistry. B

    2022  Band 126, Heft 34, Seite(n) 6575–6584

    Abstract: How phonons propagate in nanostructures determines the flow of elastic and thermal energy in dielectric materials. However, a reliable theoretical prediction of the phonon dispersion relation requires experimental verification both near to and far from ... ...

    Abstract How phonons propagate in nanostructures determines the flow of elastic and thermal energy in dielectric materials. However, a reliable theoretical prediction of the phonon dispersion relation requires experimental verification both near to and far from the Brillouin zone of the nanostructure. We report on the experimental hypersonic phonon dispersion of hard (SiO
    Sprache Englisch
    Erscheinungsdatum 2022-08-23
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1520-5207
    ISSN (online) 1520-5207
    DOI 10.1021/acs.jpcb.2c03923
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  4. Buch ; Online ; Dissertation / Habilitation: High Frequency Acoustics in Colloid-Based Meso- and Nanostructures by Spontaneous Brillouin Light Scattering

    Still, Tim

    (Springer Theses)

    2010  

    Abstract: The present thesis deals with the exploration of phononic properties ofmeso- and nanostructured colloid-based composite materials at hypersonic(GHz) frequencies. The emerging field of phononics, the mechanical analogue of photonics, treats the ... ...

    Verfasserangabe by Tim Still
    Serientitel Springer Theses
    Abstract The present thesis deals with the exploration of phononic properties ofmeso- and nanostructured colloid-based composite materials at hypersonic(GHz) frequencies. The emerging field of phononics, the mechanical analogue of photonics, treats the propagation and manipulation of acoustic waves in structured materials. Due to their widely tunable properties (size, density, etc.) and their ability to self-assembly, polymer colloids are ideal systems to realize hypersonic phononics, which are investigated by Brillouin light scattering herein. Therefore, both the mechanical and physical properties of the individual colloidal particles, which manifest in their resonance vibrations (eigenmodes), as well as the acoustic propagation in colloidal structures have been investigated.This thesis already lead to several journal publications and seven presentations at international conferences, and was honored summa cum laude.
    Schlagwörter Acoustics ; Chemistry ; Nanotechnology ; Polymers ; Surfaces (Physics) ; Technik / Wissen Chemie
    Sprache Englisch
    Umfang Online-Ressource, v.: digital
    Verlag Springer-Verlag Berlin Heidelberg
    Erscheinungsort Berlin, Heidelberg
    Dokumenttyp Buch ; Online ; Dissertation / Habilitation
    Dissertation / Habilitation Univ., Diss.--Mainz, 2009
    Anmerkung "Doctoral thesis performed at Max Planck Institute for Polymer Research and accepted by Johannes Gutenberg University, Mainz, Germany ; Includes bibliographical references and index
    ISBN 9783642134821 ; 9783642134838 ; 3642134823 ; 3642134831
    DOI 10.1007/978-3-642-13483-8
    Datenquelle Katalog der Technische Informationsbibliothek Hannover

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  5. Buch ; Dissertation / Habilitation: High frequency acoustics in colloid-based meso- and nanostructures by spontaneous Brillouin light scattering

    Still, Tim

    doctoral thesis performed at Max Planck Institute for polymer research and accepted by Johannes Gutenberg University, Mainz, Germany

    (Springer theses)

    2010  

    Verfasserangabe Tim Still
    Serientitel Springer theses
    Schlagwörter Elastische Welle ; Brillouin-Streuung ; Gigahertzbereich ; Kolloides System ; Phononischer Kristall
    Sprache Englisch
    Umfang XX, 144 S., Ill., graph. Darst, 24 cm
    Verlag Springer
    Erscheinungsort Heidelberg u.a.
    Dokumenttyp Buch ; Dissertation / Habilitation
    Dissertation / Habilitation Univ., Diss.--Mainz, 2009
    ISBN 9783642134821 ; 9783642134838 ; 3642134823 ; 3642134831
    Datenquelle Katalog der Technische Informationsbibliothek Hannover

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  6. Artikel ; Online: Shear-assisted grain coarsening in colloidal polycrystals.

    Li, Wei / Peng, Yi / Zhang, Yongjun / Still, Tim / Yodh, A G / Han, Yilong

    Proceedings of the National Academy of Sciences of the United States of America

    2020  Band 117, Heft 39, Seite(n) 24055–24060

    Abstract: Grain growth under shear annealing is crucial for controlling the properties of polycrystalline materials. However, their microscopic kinetics are not well understood because individual atomic trajectories are difficult to track. Here, we study grain ... ...

    Abstract Grain growth under shear annealing is crucial for controlling the properties of polycrystalline materials. However, their microscopic kinetics are not well understood because individual atomic trajectories are difficult to track. Here, we study grain growth with single-particle kinetics in colloidal polycrystals using video microscopy. Rich grain-growth phenomena are revealed in three shear regimes, including the normal grain growth (NGG) in weak shear melting-recrystallization process in strong shear. For intermediate shear, early stage NGG is arrested by built-up stress and eventually gives way to dynamic abnormal grain growth (DAGG). We find that DAGG occurs via a melting-recrystallization process, which naturally explains the puzzling stress drop at the onset of DAGG in metals. Moreover, we visualize that grain boundary (GB) migration is coupled with shear via disconnection gliding. The disconnection-gliding dynamics and the collective motions of ambient particles are resolved. We also observed that grain rotation can violate the conventional relation [Formula: see text] (R is the grain radius, and θ is the misorientation angle between two grains) by emission and annihilation of dislocations across the grain, resulting in a step-by-step rotation. Besides grain growth, we discover a result in shear-induced melting: The melting volume fraction varies sinusoidally on the angle mismatch between the triangular lattice orientation of the grain and the shear direction. These discoveries hold potential to inform microstructure engineering of polycrystalline materials.
    Sprache Englisch
    Erscheinungsdatum 2020-09-16
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2013456117
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Köln/Königswinter

    Zs.A 1148: Hefte anzeigen Standort:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

  7. Buch ; Online ; Dissertation / Habilitation: High frequency acoustics in colloid-based meso- and nanostructures by spontaneous Brillouin light scattering

    Still, Tim

    2009  

    Verfasserangabe vorgelegt von Tim Still
    Sprache Englisch
    Umfang Online-Ressource
    Dokumenttyp Buch ; Online ; Dissertation / Habilitation
    Dissertation / Habilitation Univ., Diss.--Mainz, 2009
    Datenquelle Katalog der Technische Informationsbibliothek Hannover

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  8. Artikel ; Online: Diffusive and martensitic nucleation kinetics in solid-solid transitions of colloidal crystals.

    Peng, Yi / Li, Wei / Wang, Feng / Still, Tim / Yodh, Arjun G / Han, Yilong

    Nature communications

    2017  Band 8, Seite(n) 14978

    Abstract: Solid-solid transitions between crystals follow diffusive nucleation, or various diffusionless transitions, but these kinetics are difficult to predict and observe. Here we observed the rich kinetics of transitions from square lattices to triangular ... ...

    Abstract Solid-solid transitions between crystals follow diffusive nucleation, or various diffusionless transitions, but these kinetics are difficult to predict and observe. Here we observed the rich kinetics of transitions from square lattices to triangular lattices in tunable colloidal thin films with single-particle dynamics by video microscopy. Applying a small pressure gradient in defect-free regions or near dislocations markedly transform the diffusive nucleation with an intermediate-stage liquid into a martensitic generation and oscillation of dislocation pairs followed by a diffusive nucleus growth. This transformation is neither purely diffusive nor purely martensitic as conventionally assumed but a combination thereof, and thus presents new challenges to both theory and the empirical criterion of martensitic transformations. We studied how pressure, density, grain boundary, triple junction and interface coherency affect the nucleus growth, shape and kinetic pathways. These novel microscopic kinetics cast new light on control solid-solid transitions and microstructural evolutions in polycrystals.
    Sprache Englisch
    Erscheinungsdatum 2017-05-15
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 2041-1723
    ISSN (online) 2041-1723
    DOI 10.1038/ncomms14978
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  9. Artikel ; Online: Heterogeneous Activation, Local Structure, and Softness in Supercooled Colloidal Liquids.

    Ma, Xiaoguang / Davidson, Zoey S / Still, Tim / Ivancic, Robert J S / Schoenholz, S S / Liu, A J / Yodh, A G

    Physical review letters

    2019  Band 122, Heft 2, Seite(n) 28001

    Abstract: We experimentally characterize heterogeneous nonexponential relaxation in bidisperse supercooled colloidal liquids utilizing a recent concept called "softness" [Phys. Rev. Lett. 114, 108001 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.108001]. Particle ... ...

    Abstract We experimentally characterize heterogeneous nonexponential relaxation in bidisperse supercooled colloidal liquids utilizing a recent concept called "softness" [Phys. Rev. Lett. 114, 108001 (2015)PRLTAO0031-900710.1103/PhysRevLett.114.108001]. Particle trajectory and structure data enable classification of particles into subgroups with different local environments and propensities to hop. We determine residence times t_{R} between particle hops and show that t_{R} derived from particles in the same softness subgroup are exponentially distributed. Using the mean residence time t[over ¯]_{R} for each softness subgroup, and a Kramers' reaction rate model, we estimate the activation energy barriers E_{b} for particle hops, and show that both t[over ¯]_{R} and E_{b} are monotonic functions of softness. Finally, we derive information about the combinations of large and small particle neighbors that determine particle softness, and we explicitly show that multiple exponential relaxation channels in the supercooled liquid give rise to its nonexponential behavior.
    Sprache Englisch
    Erscheinungsdatum 2019-02-15
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.122.028001
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

    Verfügbar in ZB MED Bonn

    Z 4' 58/153: Hefte anzeigen

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  10. Artikel: Surfactant-Induced Marangoni Eddies Alter the Coffee-Rings of Evaporating Colloidal Drops

    Still, Tim / Yodh Arjun G / Yunker Peter J

    Langmuir. 2012 Mar. 20, v. 28, no. 11

    2012  

    Abstract: The influence of the small ionic surfactant sodium dodecyl sulfate (SDS) on the evaporation of drying colloidal droplets is quantitatively investigated. The addition of SDS leads to a significantly more uniform deposition of colloidal particles after ... ...

    Abstract The influence of the small ionic surfactant sodium dodecyl sulfate (SDS) on the evaporation of drying colloidal droplets is quantitatively investigated. The addition of SDS leads to a significantly more uniform deposition of colloidal particles after evaporation (i.e., the so-called “coffee-ring effect” is dramatically altered). We understand this phenomenon in the context of circulating radial Marangoni flows induced by the variation of SDS concentration along the air–water interface. Video microscopy permits the direct visualization of the colloidal particles involved in these flows, revealing a surprisingly stable “Marangoni eddy” that prevents particle deposition at the drop perimeter.
    Schlagwörter colloids ; droplets ; drying ; evaporation ; ionic surfactants ; microscopy ; sodium dodecyl sulfate
    Sprache Englisch
    Erscheinungsverlauf 2012-0320
    Umfang p. 4984-4988.
    Erscheinungsort American Chemical Society
    Dokumenttyp Artikel
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021%2Fla204928m
    Datenquelle NAL Katalog (AGRICOLA)

    Zusatzmaterialien

    Kategorien

    Über subito bestellen

    Dieser Service ist kostenpflichtig (siehe Lieferbedingungen von subito). Bestellungen, die einen Artikel nebst Supplementary Material umfassen, werden grundsätzlich wie mehrfache Bestellungen bearbeitet. Gebühren fallen in diesen Fällen für jede einzelne Bestellung an.

Zum Seitenanfang