New Structural Anomaly Induced by Nanoconfinement

Krott, Leandro B.; Bordin, José Rafael; Barbosa, Márcia C.

doi:10.1021/jp510561t

Cited by 37 publications

(41 citation statements)

References 75 publications

(209 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…41,42 Whereas, when the nanopore has at least one degree of freedom, given by the mobility of the plates in z direction, the anomalous behavior of the fluid disappears and distinct phase transitions are observed. [43][44][45][46] CS fluids confined in nanotubes also present interesting findings, similar to obtained in atomistic models for water, as the increase in diffusion coefficient and flux for narrow nanotubes associated to a layer to single-file transition and a discontinuity in the enhancement flow factor. [47][48][49] The drawback of these core-softened potentials is that due to the simplicity of the two length scales, they are not capable to reproduce the effects related to the third coordination shell of the anomalous fluid what might be relevant under confinement.…”

Section: Introductionsupporting

confidence: 76%

Effects of confinement on anomalies and phase transitions of core-softened fluids

Krott

Bordin

Barraz

et al. 2015

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

We use molecular dynamics simulations to study how the confinement affects the dynamic, thermodynamic, and structural properties of a confined anomalous fluid. The fluid is modeled using an effective pair potential derived from the ST4 atomistic model for water. This system exhibits density, structural, and dynamical anomalies, and the vapor-liquid and liquid-liquid critical points similar to the quantities observed in bulk water. The confinement is modeled both by smooth and structured walls. The temperatures of extreme density and diffusion for the confined fluid show a shift to lower values while the pressures move to higher amounts for both smooth and structured confinements. In the case of smooth walls, the critical points and the limit between fluid and amorphous phases show a non-monotonic change in the temperatures and pressures when the nanopore size is increase. In the case of structured walls, the pressures and temperatures of the critical points varies monotonically with the pore size. Our results are explained on basis of the competition between the different length scales of the fluid and the wall-fluid interaction.

show abstract

Section: Introductionsupporting

confidence: 76%

Effects of confinement on anomalies and phase transitions of core-softened fluids

Krott

Bordin

Barraz

et al. 2015

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Besides, more importantly, the conventional assumption of non-slip flow at boundary condition is no longer applicable (Holt et al 2006;Majumder et al 2005;Neto et al 2005;Cottin-Bizonne et al 2003). It has been pointed out that the viscosity profile and slip flow are closely linked to a physical parameter: the ratio of the water-wall interaction to the water-water interaction (Krott et al 2015;Wu et al 2017;Granick et al 2003). In fact, when the ratio is higher than 1, the water in the surface region becomes ordered and a number of fluid layers are stick to the surface wall.…”

Section: Transport Mechanismsmentioning

confidence: 99%

“…It has been pointed out by many researchers that the flow behaviors of nanoconfined water vary drastically from bulk water due to strong water-wall interactions induced by nanoscale transmission channel (Heuberger et al 2001;Scatena et al 2001;Werder et al 2001;Levinger 2002;Rivera et al 2002;Köfinger et al 2008;Mashl et al 2003;Liu et al 2005a, b;Krott et al 2015;Ma et al 2015;Wu et al 2017). With the discovery of new physical phenomena, theoretical models are in need to describe and estimate these new phenomena (Wu et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Effect of critical thickness on nanoconfined water fluidity: review, communication, and inspiration

Sun

Yao

et al. 2018

J Petrol Explor Prod Technol

View full text Add to dashboard Cite

It is crucial to precisely estimate the water transport behaviors in shale formation. However, the present study on this subject is quite limited. A comprehensive literature review is conducted and some improvements are proposed. In this paper, an improved model is proposed to investigate the flow of water in nanopores of shale formation. First, a quadratic equation is proposed to build the relationship between water viscosity and contact angle. Then, the effect of critical thickness on water transport behaviors is discussed. Results show that: (a) the flow enhancement is smaller than 1 when the contact angle is smaller than 100° due to energy barrier induced by strong hydrophilicity of the nanopore wall; (b) the flow enhancement becomes infinite when the contact angle is approaching 180°; and (c) the flow enhancement increases with decreasing of critical thickness, especially for hydrophilic nanopores (the contact angle is smaller than 120°) and nanopores with a relatively small diameter (smaller than 50 nm).

show abstract

“…These results suggest an interesting physics happening under the soft wall confinements. Furthermore, MD simulations had been carried out for water-like core-softened fluids under both fixed and flexible boundaries 4 . Diffusion coefficients have been found to vary non-monotonically for core-softened fluids under fixed walls, while monotonic trend is observed for fluctuating walls 4 .…”

mentioning

confidence: 99%

“…Furthermore, MD simulations had been carried out for water-like core-softened fluids under both fixed and flexible boundaries 4 . Diffusion coefficients have been found to vary non-monotonically for core-softened fluids under fixed walls, while monotonic trend is observed for fluctuating walls 4 . The structural properties of core-softened fluid are also changed while making walls fluctuating.…”

mentioning

confidence: 99%

Soft-wall induced structure and dynamics of partially confined supercritical fluids

Ghosh

Krishnamurthy

2019

The Journal of Chemical Physics

View full text Add to dashboard Cite

The interplay between structure and dynamics of partially confined Lennard Jones (LJ) fluids, deep into the supercritical phase, are studied over a wide range of densities in the context of Frenkel line (FL), which separates rigid liquidlike and non-rigid gaslike regimes in the phase diagram of the supercritical fluids. Extensive molecular dynamics simulations carried out at the two ends of the FL (P = 5000 bar, T = 300 K and T = 1500 K) reveal intriguing features in supercritical fluids as a function of stiffness of the partially confining atomistic walls. The liquidlike regime of a LJ fluid (P = 5000 bar, T = 300 K), mimicking Argon, partially confined between walls separated by 10 Å along the z-axis, and otherwise unconstrained, reveals amorphous and liquidlike structural signatures in the radial distribution function parallel to the walls and enhanced self-diffusion as the wall stiffness is decreased. In sharp contrast, in the gas-like regime (P = 5000 bar, T = 1500 K), soft walls lead to increasing structural order hindering self-diffusion. Further, the correlations between structure and self-diffusion are found to be well captured by excess entropy. The rich behaviour shown by supercritical fluids under partial confinement, even with simple interatomic potentials, is found to be fairly independent of hydrophilicity and hydrophobicity. The study identifies persisting sub-diffusive features over intermediate time scales, emerging from the strong interplay between density and confinement, to dictate the evolution and stabilization of structures. It is anticipated that these results may help gain a better understanding of the behaviour of partially confined complex fluids found in nature.

show abstract

New Structural Anomaly Induced by Nanoconfinement

Cited by 37 publications

References 75 publications

Effects of confinement on anomalies and phase transitions of core-softened fluids

Effects of confinement on anomalies and phase transitions of core-softened fluids

Effect of critical thickness on nanoconfined water fluidity: review, communication, and inspiration

Soft-wall induced structure and dynamics of partially confined supercritical fluids

Contact Info

Product

Resources

About