Small-angle neutron-scattering investigation of short-range correlations in fractal aerogels: Simulations and experiments

Hasmy, Anwar; Foret, Marie; Pelous, J.; Jullien, R.

doi:10.1103/physrevb.48.9345

Cited by 122 publications

(110 citation statements)

References 21 publications

Supporting

Mentioning

104

Contrasting

Unclassified

Order By: Relevance

“…The fractal dimension can be estimated from the power law behavior of the scattering function, S(q) ∼ q −D in this q-range. In our case we have obtained D ∼ 1.74 consistent with the value expected for silica aerogels in three dimensions 24,25 .…”

Section: Confining Systemsupporting

confidence: 90%

“…1. The radial distribution function g(r) presents a strong peak at r = σ a , associated with bonds between contacting particles, and other features corresponding to short range correlations between particles belonging to the same cluster (see references 24,25 for further details). Before reaching the asymptotic limit of 1, g(r) exhibits a minimum corresponding to distances between particles located at the boundary of the clusters.…”

Section: Confining Systemmentioning

confidence: 99%

“…Structures with similar fractal dimension have been generated by Monte Carlo simulations using several hierarchical cluster-cluster algorithms 24,25,26 . In particular the Diffusion Limited Cluster-Cluster Aggregation procedure (DLCA) is a gel growth process widely used in theoretical studies of aerogels 25,27 .…”

Section: Introductionmentioning

confidence: 99%

“…The fractal behavior of aerogels is associated with the irreversibility of the gel formation dy-namics, which proceed by random colloidal aggregation of silica particles. The fractal dimension of silica aerogels is about 1.80 in three dimensions 24 .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Computer simulation of the phase diagram for a fluid confined in a fractal and disordered porous material

2004

View full text Add to dashboard Cite

We present a grand canonical Monte Carlo simulation study of the phase diagram of a Lennard-Jones fluid adsorbed in a fractal and highly porous aerogel. The gel environment is generated from an off-lattice diffusion limited cluster-cluster aggregation process. Simulations have been performed with the multicanonical ensemble sampling technique. The biased sampling function has been obtained by histogram reweighting calculations. Comparing the confined and the bulk system liquid-vapor coexistence curves we observe a decrease of both the critical temperature and density in qualitative agreement with experiments and other Monte Carlo studies on Lennard-Jones fluids confined in random matrices of spheres. At variance with these numerical studies we do not observe upon confinement a peak on the liquid side of the coexistence curve associated with a liquid-liquid phase coexistence. In our case only a shouldering of the coexistence curve appears upon confinement. This shoulder can be associated with high density fluctuations in the liquid phase. The coexisting vapor and liquid phases in our system show a high degree of spatial disorder and inhomogeneity.

show abstract

Section: Confining Systemsupporting

confidence: 90%

Section: Confining Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Computer simulation of the phase diagram for a fluid confined in a fractal and disordered porous material

2004

View full text Add to dashboard Cite

show abstract

“…The log-log curves exhibit the same qualitative shape as for DLCA [12], i.e. a maximum at low-q, which is shifted to larger q as the concentration increases, an intermediate fractal linear regime, followed by damped oscillations (characteristic of the short range order between particles [14]) at larger q-values. However, for c > ∼ c g , the absolute value of the fractal slope (≃ 2.3) is significantly larger than in DLCA and decreases slowly as c increases.…”

mentioning

confidence: 66%

Fluctuating Bond Aggregation: A Model for Chemical Gel Formation

Jullien¹,

Hasmy²

1995

Phys. Rev. Lett.

Self Cite

View full text Add to dashboard Cite

The Diffusion-Limited Cluster-Cluster Aggregation (DLCA) model is modified by including cluster deformations using the bond fluctuation algorithm.From 3d computer simulations, it is shown that, below a given threshold value c g of the volumic fraction c, the realization of all intra-aggregate bonding possibilities prevents the formation of a gelling network. For c > c g , the sol-gel transition occurs at a time t g which, in contrast to DLCA, doesnot diverge with the box size. Several results are reported including small angle scattering curves and possible applications are discussed.

show abstract

Theoretical Modeling of the Thermal and Mechanical Structure‐Property Relationships in Aerogels

Rege,

Milow

2024

Aerogels for Energy Saving and Storage

View full text Add to dashboard Cite

Small-angle neutron-scattering investigation of short-range correlations in fractal aerogels: Simulations and experiments

Cited by 122 publications

References 21 publications

Computer simulation of the phase diagram for a fluid confined in a fractal and disordered porous material

Computer simulation of the phase diagram for a fluid confined in a fractal and disordered porous material

Fluctuating Bond Aggregation: A Model for Chemical Gel Formation

Theoretical Modeling of the Thermal and Mechanical Structure‐Property Relationships in Aerogels

Contact Info

Product

Resources

About