Anomalous diffusion of molecules with rotating polar groups: The joint role played by inertia and dipole coupling in microwave and far-infrared absorption

Титов, С. В.; Coffey, W. T.; Dowling, William J.; Zarifakis, M.; Kalmykov, Yuri P.; Titov, A. S.

doi:10.1103/physreve.102.052130

Cited by 3 publications

(2 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, molecular simulations proved the formation of a vacuum layer around a high-frequency vibrating nanoparticle in water . Also, high-frequency thermoacoustic waves can induce a refractive index modulation with pressure and temperature in water, , which can be probed by detecting liquid resonances, e.g., by nanoplasmonics . This effect could be exploited to realize realistic transduction systems, able to probe the water behavior in extreme conditions …”

Section: Discussionmentioning

confidence: 99%

Acoustic Wave Generation in Nanofluids: Effect of the Kapitza Resistance on the Thermophone to Mechanophone Generation Mechanism Transition

2023

View full text Add to dashboard Cite

High frequency, short wavelength acoustic wave generation in fluids, by means of immersed nanotransducers, is key to applications ranging from the biomedical to the ICT sector, all the way to investigating fundamental aspects of the mechanics of fluids. In this context, the commonly adopted generation mechanism is the thermophone, where the nanotransducer serves as a nanoheater for the surrounding fluid and the acoustic wave is launched by water thermal expansion. Its performance, however, is severely degraded when reaching up to hypersonic frequencies. We analytically investigate the thermoacoustic response in the frequency domain for the case of a gold nanofilm transducer in contact with water. We prove that another generation mechanism, the mechanophone, sets in this critical frequency range, widening the acoustic generation bandwidth. In the mechanophone, it is the nanotransducer thermal expansion that launches pressure waves in water. We find a threshold frequency discriminating between these two regimes, which can be tuned by acting on the Kapitza resistance at the solid−liquid interface. We then show how the mechanophone mechanism can be activated in the frame of photoacoustic generation with pulsed laser sources. The unveiled physics bears generality beyond the specific system and explains the acoustic generation mechanisms in nanofluids.

show abstract

Section: Discussionmentioning

confidence: 99%

Acoustic Wave Generation in Nanofluids: Effect of the Kapitza Resistance on the Thermophone to Mechanophone Generation Mechanism Transition

2023

View full text Add to dashboard Cite

show abstract

“…The aim of this paper is to propose a generalisation of the rotational diffusion equation with a memory kernel and to show that it is possible to retrieve different relaxation behaviours from a single model. The rotational diffusion equation is still one of the most exploited models for the analysis of orientational relaxation in systems with polar molecules; see [30] and references therein. Conversely, the memory kernel approach has been proved to enable a robust treatment of the relaxation dynamics of molecular solutes in viscous solvents, and recently, much attention has been paid also to the experimental extraction of the memory kernels for particular systems of interest; see [31] and references therein.…”

Section: Introductionmentioning

confidence: 99%

Tuning of the Dielectric Relaxation and Complex Susceptibility in a System of Polar Molecules: A Generalised Model Based on Rotational Diffusion with Resetting

et al. 2022

View full text Add to dashboard Cite

The application of the fractional calculus in the mathematical modelling of relaxation processes in complex heterogeneous media has attracted a considerable amount of interest lately. The reason for this is the successful implementation of fractional stochastic and kinetic equations in the studies of non-Debye relaxation. In this work, we consider the rotational diffusion equation with a generalised memory kernel in the context of dielectric relaxation processes in a medium composed of polar molecules. We give an overview of existing models on non-exponential relaxation and introduce an exponential resetting dynamic in the corresponding process. The autocorrelation function and complex susceptibility are analysed in detail. We show that stochastic resetting leads to a saturation of the autocorrelation function to a constant value, in contrast to the case without resetting, for which it decays to zero. The behaviour of the autocorrelation function, as well as the complex susceptibility in the presence of resetting, confirms that the dielectric relaxation dynamics can be tuned by an appropriate choice of the resetting rate. The presented results are general and flexible, and they will be of interest for the theoretical description of non-trivial relaxation dynamics in heterogeneous systems composed of polar molecules.

show abstract

Anomalous diffusion, gigahertz, and terahertz spectroscopy of aliphatic ketones

Titov

Vij

2022

Phys. Rev. E

View full text Add to dashboard Cite

Anomalous diffusion of molecules with rotating polar groups: The joint role played by inertia and dipole coupling in microwave and far-infrared absorption

Cited by 3 publications

References 30 publications

Acoustic Wave Generation in Nanofluids: Effect of the Kapitza Resistance on the Thermophone to Mechanophone Generation Mechanism Transition

Acoustic Wave Generation in Nanofluids: Effect of the Kapitza Resistance on the Thermophone to Mechanophone Generation Mechanism Transition

Tuning of the Dielectric Relaxation and Complex Susceptibility in a System of Polar Molecules: A Generalised Model Based on Rotational Diffusion with Resetting

Anomalous diffusion, gigahertz, and terahertz spectroscopy of aliphatic ketones

Contact Info

Product

Resources

About