1
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De Francesco A, Scaccia L, Formisano F, Guarini E, Bafile U, Nykypanchuk D, Alatas A, Li M, Lynch ST, Cunsolo A. The Effect of Embedded Nanoparticles on the Phonon Spectrum of Ice: An Inelastic X-ray Scattering Study. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:918. [PMID: 36903796 PMCID: PMC10005414 DOI: 10.3390/nano13050918] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/19/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
As a contribution to the ongoing effort toward high-frequency sound manipulation in composite materials, we use Inelastic X-ray Scattering to probe the phonon spectrum of ice, either in a pure form or with a sparse amount of nanoparticles embedded in it. The study aims at elucidating the ability of nanocolloids to condition the collective atomic vibrations of the surrounding environment. We observe that a nanoparticle concentration of about 1 % in volume is sufficient to visibly affect the phonon spectrum of the icy substrate, mainly canceling its optical modes and adding nanoparticle phonon excitations to it. We highlight this phenomenon thanks to the lineshape modeling based on a Bayesian inference, which enables us to capture the finest detail of the scattering signal. The results of this study can empower new routes toward the shaping of sound propagation in materials through the control of their structural heterogeneity.
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Affiliation(s)
- Alessio De Francesco
- CNR-IOM & INSIDE@ILL c/o Operative Group in Grenoble (OGG), F-38042 Grenoble, France
- Institut Laue-Langevin (ILL), F-38042 Grenoble, France
| | - Luisa Scaccia
- Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, I-62100 Macerata, Italy
| | - Ferdinando Formisano
- CNR-IOM & INSIDE@ILL c/o Operative Group in Grenoble (OGG), F-38042 Grenoble, France
- Institut Laue-Langevin (ILL), F-38042 Grenoble, France
| | - Eleonora Guarini
- Dipartimento di Fisica e Astronomia, Università di Firenze, Via G. Sansone 1, I-50019 Sesto Fiorentino, Italy
| | - Ubaldo Bafile
- Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata ”Nello Carrara”, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy
| | - Dmytro Nykypanchuk
- Brookhaven National Laboratory-National Synchrotron Light Source-NSLS II, P.O. Box 5000, Upton, NY 11973, USA
| | - Ahmet Alatas
- Argonne National Laboratory, Advanced Photon Source, P.O. Box 5000, Upton, NY 11973, USA
| | - Mingda Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Scott T. Lynch
- Department of Physics, University of Wisconsin—Madison, 1150 University Avenue, Madison, WI 53706, USA
| | - Alessandro Cunsolo
- Department of Physics, University of Wisconsin—Madison, 1150 University Avenue, Madison, WI 53706, USA
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2
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Altering Terahertz Sound Propagation in a Liquid upon Nanoparticle Immersion. NANOMATERIALS 2022; 12:nano12142401. [PMID: 35889625 PMCID: PMC9318512 DOI: 10.3390/nano12142401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 11/25/2022]
Abstract
One of the grand challenges of new generation Condensed Matter physicists is the development of novel devices enabling the control of sound propagation at terahertz frequency. Indeed, phonon excitations in this frequency window are the leading conveyor of heat transfer in insulators. Their manipulation is thus critical to implementing heat management based on the structural design. To explore the possibility of controlling the damping of sound waves, we used high spectral contrast Inelastic X-ray Scattering (IXS) to comparatively study terahertz acoustic damping in a dilute suspension of 50 nm nanospheres in glycerol and on pure glycerol. Bayesian inference-based modeling of measured spectra indicates that, at sufficiently large distances, the spectral contribution of collective modes in the glycerol suspension becomes barely detectable due to the enhanced damping, the weakening, and the slight softening of the dominant acoustic mode.
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3
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Lynch ST, De Francesco A, Scaccia L, Cunsolo A. Controlling terahertz sound propagation: some preliminary Inelastic X-Ray Scattering result. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202227201010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The control of sound propagation in materials via the design of their elastic properties is an exciting task at the forefront of Condensed Matter. It becomes especially compelling at terahertz frequencies, where phonons are the primary conveyors of heat flow. Despite the increasing focus on this goal, this field of research is still in its infancy; To achieve a few advances in this field, we performed several Inelastic X-Ray Scattering (IXS) measurements on elementary systems as dilute suspensions of nanoparticles (NPs) in liquids. We found that nanoparticles can effectively impact the sound propagation of the hosting liquid. We also explored the possibility of shaping terahertz sound propagation in a liquid upon confinement on quasi-unidimensional cavities. These results are here reviewed and discussed, and future research directions are finally outlined.
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De Francesco A, Scaccia L, Formisano F, Guarini E, Bafile U, Maccarini M, Zhang Y, Nykypanchuck D, Alatas A, Cunsolo A. The damping of terahertz acoustic modes in aqueous nanoparticle suspensions. Sci Rep 2021; 11:20110. [PMID: 34635734 PMCID: PMC8505432 DOI: 10.1038/s41598-021-99503-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 09/20/2021] [Indexed: 11/23/2022] Open
Abstract
In this work, we investigate the possibility of controlling the acoustic damping in a liquid when nanoparticles are suspended in it. To shed light on this topic, we performed Inelastic X-Ray Scattering (IXS) measurements of the terahertz collective dynamics of aqueous suspensions of nanospheres of various materials, size, and relative concentration, either charged or neutral. A Bayesian analysis of measured spectra indicates that the damping of the two acoustic modes of water increases upon nanoparticle immersion. This effect seems particularly pronounced for the longitudinal acoustic mode, which, whenever visible at all, rapidly damps off when increasing the exchanged wavevector. Results also indicate that the observed effect strongly depends on the material the immersed nanoparticles are made of.
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Affiliation(s)
- Alessio De Francesco
- CNR-IOM & INSIDE@ILL c/o Operative Group in Grenoble (OGG), 38042, Grenoble, France
- Institut Laue-Langevin (ILL), 38042, Grenoble, France
| | - Luisa Scaccia
- Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, 62100, Macerata, Italy
| | - Ferdinando Formisano
- CNR-IOM & INSIDE@ILL c/o Operative Group in Grenoble (OGG), 38042, Grenoble, France
- Institut Laue-Langevin (ILL), 38042, Grenoble, France
| | - Eleonora Guarini
- Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, 50019, Sesto Fiorentino, Italy
| | - Ubaldo Bafile
- Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata "Nello Carrara", via Madonna del Piano 10, 50019, Sesto Fiorentino, Italy
| | - Marco Maccarini
- Laboratoire TIMC/IMAG UMR CNRS 5525, Université Grenoble-Alpes, 38000, Grenoble, France
| | - Yugang Zhang
- Brookhaven National Laboratory, Center for Functional Nanomaterials, P.O. Box 5000, Upton, 11973, NY, USA
| | - Dmytro Nykypanchuck
- Brookhaven National Laboratory, Center for Functional Nanomaterials, P.O. Box 5000, Upton, 11973, NY, USA
| | - Ahmet Alatas
- Argonne National Laboratory, Advanced Photon Source, P.O. Box 5000, Upton, 11973, NY, USA
| | - Alessandro Cunsolo
- Department of Physics, University of Wisconsin at Madison, 1150 University Avenue, Madison, WI, USA.
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5
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Nguyen T, Andrejevic N, Po HC, Song Q, Tsurimaki Y, Drucker NC, Alatas A, Alp EE, Leu BM, Cunsolo A, Cai YQ, Wu L, Garlow JA, Zhu Y, Lu H, Gossard AC, Puretzky AA, Geohegan DB, Huang S, Li M. Signature of Many-Body Localization of Phonons in Strongly Disordered Superlattices. NANO LETTERS 2021; 21:7419-7425. [PMID: 34314183 DOI: 10.1021/acs.nanolett.1c01905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Many-body localization (MBL) has attracted significant attention because of its immunity to thermalization, role in logarithmic entanglement entropy growth, and opportunities to reach exotic quantum orders. However, experimental realization of MBL in solid-state systems has remained challenging. Here, we report evidence of a possible phonon MBL phase in disordered GaAs/AlAs superlattices. Through grazing-incidence inelastic X-ray scattering, we observe a strong deviation of the phonon population from equilibrium in samples doped with ErAs nanodots at low temperature, signaling a departure from thermalization. This behavior occurs within finite phonon energy and wavevector windows, suggesting a localization-thermalization crossover. We support our observation by proposing a theoretical model for the effective phonon Hamiltonian in disordered superlattices, and showing that it can be mapped exactly to a disordered 1D Bose-Hubbard model with a known MBL phase. Our work provides momentum-resolved experimental evidence of phonon localization, extending the scope of MBL to disordered solid-state systems.
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Affiliation(s)
- Thanh Nguyen
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Nina Andrejevic
- Department of Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Hoi Chun Po
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Qichen Song
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yoichiro Tsurimaki
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Nathan C Drucker
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Ahmet Alatas
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Esen E Alp
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Bogdan M Leu
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Physics, Miami University, Oxford, Ohio 45056, United States
| | - Alessandro Cunsolo
- Department of Physics, University of Wisconsin at Madison, Madison, Wisconsin 53706, United States
| | - Yong Q Cai
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Lijun Wu
- Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Joseph A Garlow
- Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Yimei Zhu
- Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Hong Lu
- College of Engineering and Applied Sciences, Nanjing University, Nanjing, China
| | - Arthur C Gossard
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Alexander A Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - David B Geohegan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Shengxi Huang
- Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mingda Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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6
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De Francesco A, Bafile U, Cunsolo A, Scaccia L, Guarini E. Searching for a second excitation in the inelastic neutron scattering spectrum of a liquid metal: a Bayesian analysis. Sci Rep 2021; 11:13974. [PMID: 34234260 PMCID: PMC8263748 DOI: 10.1038/s41598-021-93452-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 06/24/2021] [Indexed: 12/04/2022] Open
Abstract
When probed at nanometer and picosecond scales, the properties of a liquid present striking analogies with the ones of the corresponding solid, one of the most surprising is the ability of supporting shear wave propagation, as a rigid medium. Although this evidence is being reported by a growing number of terahertz scattering measurements, it remains an open question whether it is universal or rather typical of some liquids only. Furthermore, given its elusive signatures in the scattering signal, the detection of this effect appears as a typical case where an unintentional “bias of confirmation” can mislead experimentalists. We thus decided to use a Bayesian inference approach to achieve a probabilistically grounded and evidence-based lineshape modeling of the inelastic neutron scattering spectra from liquid silver, whose simulated density autocorrelations bear evidence of a shear mode propagation over very short distances. The result of our analysis indicates that the observation of any additional, non-longitudinal, acoustic modes in this simple system goes beyond the accuracy of the used scattering method.
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Affiliation(s)
- Alessio De Francesco
- CNR-IOM & INSIDE@ILL c/o Operative Group in Grenoble (OGG), F-38042, Grenoble, France.,Institut Laue-Langevin (ILL), F-38042, Grenoble, France
| | - Ubaldo Bafile
- Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata "Nello Carrara", Via Madonna del Piano 10, I-50019, Sesto Fiorentino, Italy
| | - Alessandro Cunsolo
- Department of Physics, University of Wisconsin at Madison, 1150 University Avenue, Madison, WI, USA
| | - Luisa Scaccia
- Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, I-62100, Macerata, Italy
| | - Eleonora Guarini
- Dipartimento di Fisica e Astronomia, Università di Firenze, Via G. Sansone 1, I-50019, Sesto Fiorentino, Italy.
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7
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De Francesco A, Scaccia L, Formisano F, Guarini E, Bafile U, Maccarini M, Alatas A, Cai YQ, Nykypanchuk D, Cunsolo A. Onset of interfacial waves in the terahertz spectrum of a nanoparticle suspension. Phys Rev E 2020; 102:022601. [PMID: 32942392 DOI: 10.1103/physreve.102.022601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/13/2020] [Indexed: 11/06/2022]
Abstract
We used inelastic x-ray scattering to gain insight into the complex terahertz dynamics of a diluted Au-nanoparticle suspension in glycerol. We observe that, albeit sparse, Au nanoparticles leave clear signatures on the dynamic response of the system, the main one being an additional mode propagating at the nanoparticle-glycerol interface. A Bayesian inferential analysis of the line shape reveals that such a mode, at variance with conventional acoustic modes, keeps a hydrodynamiclike behavior well beyond the continuous limit and down to subnanometer distances.
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Affiliation(s)
- Alessio De Francesco
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Operative Group in Grenoble (OGG) F-38042 Grenoble, France.,Institut Laue-Langevin (ILL), F-38042 Grenoble, France
| | - Luisa Scaccia
- Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, 62100 Macerata, Italy
| | - Ferdinando Formisano
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Operative Group in Grenoble (OGG) F-38042 Grenoble, France.,Institut Laue-Langevin (ILL), F-38042 Grenoble, France
| | - Eleonora Guarini
- Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy
| | - Ubaldo Bafile
- Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata "Nello Carrara," via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy
| | - Marco Maccarini
- Université Grenoble-Alpes, CNRS, Grenoble INP, TIMC-IMAG, 38000 Grenoble, France
| | - Ahmet Alatas
- Argonne National Laboratory, Advanced Photon Source, P.O. Box 5000, Upton, New York 11973, USA
| | - Yong Q Cai
- Brookhaven National Laboratory, National Synchrotron Light Source, NSLS II, P.O. Box 5000, Upton, New York 11973, USA
| | - Dmytro Nykypanchuk
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Alessandro Cunsolo
- Brookhaven National Laboratory, National Synchrotron Light Source, NSLS II, P.O. Box 5000, Upton, New York 11973, USA
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8
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De Francesco A, Scaccia L, Formisano F, Guarini E, Bafile U, Maccarini M, Alatas A, Cai YQ, Cunsolo A. The Terahertz Dynamics of an Aqueous Nanoparticle Suspension: An Inelastic X-ray Scattering Study. NANOMATERIALS 2020; 10:nano10050860. [PMID: 32365679 PMCID: PMC7711609 DOI: 10.3390/nano10050860] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 11/16/2022]
Abstract
We used the high-resolution Inelastic X-ray Scattering beamline of the Advanced Photon Source at Argonne National Laboratory to measure the terahertz spectrum of pure water and a dilute aqueous suspension of 15 nm diameter spherical Au nanoparticles (Au-NPs). We observe that, despite their sparse volume concentration of about 0.5%, the immersed NPs strongly influence the collective molecular dynamics of the hosting liquid. We investigate this effect through a Bayesian inference analysis of the spectral lineshape, which elucidates how terahertz transport properties of water change upon Au-NP immersion. In particular, we observe a nearly complete disappearance of the longitudinal acoustic mode and a mildly decreased ability to support shear wave propagation.
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Affiliation(s)
- Alessio De Francesco
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Operative Group in Grenoble (OGG), F-38042 Grenoble, France; (A.D.F.); (F.F.)
- Institut Laue-Langevin (ILL), F-38042 Grenoble, France
| | - Luisa Scaccia
- Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, 62100 Macerata, Italy;
| | - Ferdinando Formisano
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Operative Group in Grenoble (OGG), F-38042 Grenoble, France; (A.D.F.); (F.F.)
- Institut Laue-Langevin (ILL), F-38042 Grenoble, France
| | - Eleonora Guarini
- Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy;
| | - Ubaldo Bafile
- Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata ”Nello Carrara”, via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy;
| | - Marco Maccarini
- Université Grenoble-Alpes - Laboratoire TIMC/IMAG UMR CNRS 5525, 38000 Grenoble, France;
| | - Ahmet Alatas
- Argonne National Laboratory, Advanced Photon Source, P.O. Box 5000 Upton, 11973 NY, USA;
| | - Yong Q. Cai
- Brookhaven National Laboratory-National Synchrotron Light Source-NSLS II, P.O. Box 5000, Upton, 11973 NY, USA;
| | - Alessandro Cunsolo
- Brookhaven National Laboratory-National Synchrotron Light Source-NSLS II, P.O. Box 5000, Upton, 11973 NY, USA;
- Correspondence: ; Tel.: +1-631-327-1927
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9
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De Francesco A, Scaccia L, Maccarini M, Formisano F, Guarini E, Bafile U, Cunsolo A. Interpreting the Terahertz Spectrum of Complex Materials: The Unique Contribution of the Bayesian Analysis. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E2914. [PMID: 31505798 PMCID: PMC6766264 DOI: 10.3390/ma12182914] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/19/2019] [Accepted: 08/29/2019] [Indexed: 11/16/2022]
Abstract
In the last few decades, experimental studies of the terahertz spectrum of density fluctuations have considerably improved our knowledge of the mesoscopic dynamics of disordered materials, which also have imposed new demands on the data modelling and interpretation. Indeed, lineshape analyses are no longer limited to the phenomenological observation of inelastic features, as in the pioneering stage of Neutron or X-ray spectroscopy, rather aiming at the extraction from their shape of physically relevant quantities, as sound velocity and damping, relaxation times, or other transport coefficients. In this effort, researchers need to face both inherent and practical obstacles, respectively stemming from the highly damped nature of terahertz modes and the limited energy resolution, accessible kinematic region and statistical accuracy of the typical experimental outcome. To properly address these challenges, a global reconsideration of the lineshape modelling and the enforcement of evidence-based probabilistic inference is becoming crucial. Particularly compelling is the possibility of implementing Bayesian inference methods, which we illustrated here through an in-depth discussion of some results recently obtained in the analysis of Neutron and X-ray scattering results.
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Affiliation(s)
- Alessio De Francesco
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Operative Group in Grenoble (OGG), c/o Institut Laue Langevin, 38042 Grenoble, France
| | - Luisa Scaccia
- Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, 62100 Macerata, Italy
| | - Marco Maccarini
- Laboratoire TIMC/IMAG UMR CNRS 5525 Grenoble, Université Grenoble-Alpes, 38000 Grenoble, France
| | - Ferdinando Formisano
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Operative Group in Grenoble (OGG), c/o Institut Laue Langevin, 38042 Grenoble, France
| | - Eleonora Guarini
- Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy
| | - Ubaldo Bafile
- Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata "Nello Carrara", via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy
| | - Alessandro Cunsolo
- Brookhaven National Laboratory-National Synchrotron Light Source-NSLS II, P.O. Box 5000, Upton, NY 11973, USA.
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10
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De Francesco A, Scaccia L, Lennox RB, Guarini E, Bafile U, Falus P, Maccarini M. Model-free description of polymer-coated gold nanoparticle dynamics in aqueous solutions obtained by Bayesian analysis of neutron spin echo data. Phys Rev E 2019; 99:052504. [PMID: 31212567 DOI: 10.1103/physreve.99.052504] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Indexed: 11/07/2022]
Abstract
We present a neutron spin echo study of the nanosecond dynamics of polyethylene glycol (PEG) functionalized nanosized gold particles dissolved in D_{2}O at two temperatures and two different PEG molecular weights (400D and 2000D). The analysis of the neutron spin echo data was performed by applying a Bayesian approach to the description of time correlation function decays in terms of exponential terms, recently proved to be theoretically rigorous. This approach, which addresses in a direct way the fundamental issue of model choice in any dynamical analysis, provides here a guide to the most statistically supported way to follow the decay of the intermediate scattering functions I(Q,t) by basing on statistical grounds the choice of the number of terms required for the description of the nanosecond dynamics of the studied systems. Then, the presented analysis avoids from the start resorting to a preselected framework and can be considered as model free. By comparing the results of PEG-coated nanoparticles with those obtained in PEG2000 solutions, we were able to disentangle the translational diffusion of the nanoparticles from the internal dynamics of the polymer grafted to them, and to show that the polymer corona relaxation follows a pure exponential decay in agreement with the behavior predicted by coarse grained molecular dynamics simulations and theoretical models. This methodology has one further advantage: in the presence of a complex dynamical scenario, I(Q,t) is often described in terms of the Kohlrausch-Williams-Watts function that can implicitly represent a distribution of relaxation times. By choosing to describe the I(Q,t) as a sum of exponential functions and with the support of the Bayesian approach, we can explicitly determine when a finer-structure analysis of the dynamical complexity of the system exists according to the available data without the risk of overparametrization. The approach presented here is an effective tool that can be used in general to provide an unbiased interpretation of neutron spin echo data or whenever spectroscopy techniques yield time relaxation data curves.
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Affiliation(s)
- Alessio De Francesco
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali c/o OGG Grenoble, France
| | - Luisa Scaccia
- Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, 62100 Macerata, Italy
| | - R Bruce Lennox
- Department of Chemistry, McGill University, Sherbrooke St. West, Montreal, Canada
| | - Eleonora Guarini
- Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy
| | - Ubaldo Bafile
- Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata "Nello Carrara", via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy
| | | | - Marco Maccarini
- Université Grenoble Alpes-Laboratoire TIMC/IMAG UMR CNRS 5525 Grenoble, France
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