Diffusion of Gold Nanoparticles in Inverse Opals Probed by Heterodyne Dynamic Light Scattering

Giraudet, Cédric; Knoll, Matthias; Galvan, Yaraset; Süß, Sebastian; Segets, Doris; Vogel, Nicolas; Rausch, Michael H.; Fröba, Andreas P.

doi:10.1007/s11242-019-01364-1

Cited by 11 publications

(7 citation statements)

References 52 publications

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“…in which MS diffusivities are computed using Equations (16)- (18). The validity of the generalised correction terms shown in Equations (22) and (23) was tested in the study by Jamali et al [117] using a ternary mixture of chloroform/acetone/ methanol, and 28 different ternary LJ liquids. In Figures 4 and 5, we show the computed Fick and MS diffusion coefficients of the ternary molecular mixture of chloroform (x 1 = 0.3), acetone (x 2 = 0.3) and methanol (x 3 = 0.4).…”

Section: Ternary Mixturesmentioning

confidence: 99%

“…Figure 10 shows that all MS diffusion coefficients are sizedependent. The finite-size correction for MS diffusivities is only a function of the YH term because the matrix of thermodynamic factors is equal to the identity matrix (see Equation (23)). Deviations between MS diffusivities corrected using the analytic correction and the ones obtained by linear extrapolation to the thermodynamic limit are in the range of 0 to 4.5%.…”

Section: Quaternary Mixturesmentioning

confidence: 99%

“…Since then, experimental methods for measuring the diffusivity in liquids have significantly improved. Such methods include Nuclear Magnetic Resonance (NMR) [20], Raman Micro-spectroscopy [21], Dynamic Light Scattering (DLS) [22,23] and holographic interferometry [24]. Despite this progress, experimental measurements are often challenging to perform.…”

Section: Introductionmentioning

confidence: 99%

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Finite-size effects of diffusion coefficients computed from molecular dynamics: a review of what we have learned so far

Celebi

Jamali

Bardow

et al. 2020

Molecular Simulation

100

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The number of molecules used in a typical Molecular Dynamics (MD) simulations is orders of magnitude lower than in the thermodynamic limit. It is therefore essential to correct diffusivities computed from Molecular Dynamics simulations for finite-size effects. We present a comprehensive review on finitesize effects of diffusion coefficients by considering self-, Maxwell-Stefan, and Fick diffusion coefficients in pure liquids, as well as binary, ternary, and quaternary mixtures. All finite-size corrections, both analytical and empirical, are discussed in detail. The finite-size effects of rotational and confined diffusion are also briefly discussed.

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Section: Ternary Mixturesmentioning

confidence: 99%

Section: Quaternary Mixturesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Finite-size effects of diffusion coefficients computed from molecular dynamics: a review of what we have learned so far

Celebi

Jamali

Bardow

et al. 2020

Molecular Simulation

100

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show abstract

“…As expected, the side-view SEM image showed that only the outermost pore layer was coated with silica nanoparticles. Similar to the case of the porous monolith, we first hypothesized that the 20 nm SiO 2 particles were not able to coat the inner pores because of two reasons: the necks in the first row of pores are potentially clogged with PDADMAC and SiO 2 that attract each other and the diffusion limitations, , which are even more pronounced because of the considerably smaller pores and the necks that connect them. We then applied the developed coating strategy toward the inverse opals in which we capitalize on convection to enhance the mass transport of colloidal particles into the pore network (Figure (b)).…”

Section: Results and Discussionmentioning

confidence: 99%

Materials with Hierarchical Porosity Enhance the Stability of Infused Ionic Liquid Films

et al. 2021

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Defined surface functionalities can control the properties of a material. The layer-by-layer method is an experimentally simple yet very versatile method to coat a surface with nanoscale precision. The method is widely used to either control the chemical properties of the surface via the introduction of functional moieties bound to the polymer or create nanoscale surface topographies if one polymeric species is replaced by a colloidal dispersion. Such roughness can enhance the stability of a liquid film on top of the surface by capillary adhesion. Here, we investigate whether a similar effect allows an increased retention of liquid films within a porous surface and thus potentially increases the stability of ionic liquid films infused within a porous matrix in the supported ionic liquid-phase catalysis. The complex geometry of the porous material, long diffusion pathways, and small sizes of necks connecting individual pores all contribute to difficulties to reliably coat the required porous materials. We optimize the coating process to ensure uniform surface functionalization via two steps. Diffusion limitations are overcome by force-wetting the pores, which transports the functional species convectively into the materials. Electrostatic repulsion, which can limit pore accessibility, is mitigated by the addition of electrolytes to screen charges. We introduce nanoscale topography in microscale porous SiC monoliths to enhance the retention of an ionic liquid film. We use γ-Al 2 O 3 to coat monoliths and test the retention of 1-butyl-2,3-dimethylimidazolium chloride under exposure to a continuous gas stream, a setup commonly used in the water-gas shift reaction. Our study showcases that a hierarchical topography can improve the stability of impregnated ionic liquid films, with a potential advantage of improved supported ionic liquid-phase catalysis.

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“…The mobility of nanoscale particles suspended in fluids within confined geometries impacts a wide range of fields including biotechnology, catalysis, nanofabrication, lubrication, and environmental remediation . Under nanometer-scale confinement, the Brownian diffusion that nanoparticles typically experience in a bulk fluid can be radically altered due to hydrodynamic, surface, and other interactions that become paramount when the particles are restricted to remain in close proximity to the bounding surfaces. − A number of experimental approaches have been employed to characterize nanoparticle mobility under such conditions. − In particular, recent advances in transmission electron microscopy (TEM) in liquid environments have enabled detailed single-particle-tracking experiments that have investigated nanoparticle motion in fluids under nanoscale confinement, − and in several cases, these studies have revealed dynamics that are orders of magnitude slower than the corresponding Brownian motion in bulk. ,, Such microscopy methods are well suited for tracking nanoparticles that are confined along one direction, such as between closely spaced parallel substrates. However, other important confinement geometries for nanoparticle mobility, such as within bulk nanoporous and mesoporous materials, present a challenge for established techniques.…”

Section: Introductionmentioning

confidence: 99%

Extremely Slow Diffusion of Gold Nanoparticles under Confinement in Mesoporous Silica

et al. 2022

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We report an X-ray photon correlation spectroscopy (XPCS) study of the mobility of colloidal gold nanoparticles with a diameter of approximately 4 nm in glycerol under confinement within the channels of SBA-15 mesoporous silica with pore diameters of approximately 6 and 12 nm. The XPCS correlation functions result from an effective heterodyne signal due to the mixing of the coherent scattering from the nanoparticles and the mesoporous silica. Over the range of wave vectors and hence length scales probed, the nanoparticle dynamics are well described by one-dimensional diffusion. The nanoparticle diffusivity varies with temperature in a manner expected based on the temperature-dependent viscosity of glycerol; however, the magnitudes of the diffusion coefficients are several orders of magnitude smaller than those of the nanoparticles in bulk glycerol. We consider mechanisms that might contribute to this reduction in diffusivity including enhancement in hydrodynamic drag under confinement, effects of nanoparticle adsorption to the pore walls, and slowing structural dynamics in glycerol due to the combination of the nanometer-scale confinement and the presence of the nanoparticles.

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Diffusion of Gold Nanoparticles in Inverse Opals Probed by Heterodyne Dynamic Light Scattering

Cited by 11 publications

References 52 publications

Finite-size effects of diffusion coefficients computed from molecular dynamics: a review of what we have learned so far

Finite-size effects of diffusion coefficients computed from molecular dynamics: a review of what we have learned so far

Materials with Hierarchical Porosity Enhance the Stability of Infused Ionic Liquid Films

Extremely Slow Diffusion of Gold Nanoparticles under Confinement in Mesoporous Silica

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