Fractal analysis of surface roughness of montmorillonite clay self-supported films: Effects of exchanged cations and of mechanical tensile stress

Zabat, Mokhtar; Harba, Rachid; Damme, H. Van

doi:10.1016/j.colsurfa.2015.09.001

Cited by 4 publications

(6 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…dilute or concentrate state) is also a factor to take into account. Figure 10 shows two extreme types of microtextures of clays 10,15 : stacked or "brick-like" in which the layers are locally organized in assemblies of thick and rigid crystallites (large coherence length) with large porosity and open texture; and entangled or "sheet-like" with longer flexible layers assembled (low coherence length) with small total porosity and small open porosity (with lenticular pores). These configurations correspond to a concentrated regime.…”

Section: Discussion On the Flexibility And Microtexture Of Claysmentioning

confidence: 99%

“…In a dilute regime, layers of lithium (Li + )-saturated smectites are reported to be isolated 10 ; SAXS experiments suggest that exfoliated layers can also be observed in suspensions of Na + exchanged smectites 43 . Stacking of layers shows up from Na + -saturated smectites and increases following the sequence in dilute regime: Na + < K + < Mg 2+ < Ca 2+ ; with calcium saturated smectite reaching 7 layers 10 . In suspensions, most of the smectites present themselves in the form of particles instead of single layers, even in very dilute regimes 10 .…”

Section: Discussion On the Flexibility And Microtexture Of Claysmentioning

confidence: 99%

“…Therefore, a single (exfoliated) clay layer can exhibit a highly bent form even due to stirring in solution.. Experimental observations suggest that suspesions of Li + and Na + exchanged smectites present exfoliated layers 10,43 , and this occurs even if the multiple hydrodynamical interactions tend to put particles parallel to each other.…”

Section: Bending Modulus Of a Single Clay Layermentioning

confidence: 99%

“…Locally, in solid clay samples, clay nanolayers are in general structured in ordered (stacked) domains with adsorbed fluid in-between the layers. The stacking process likely stems from the attractive component of the electrostatic interactions modulated by the hydration forces 10 . These locally ordered domains are sometimes designated as crystallites or clays platelets.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Flexibility of nanolayers and stacks: implications in the nanostructuration of clays

et al. 2018

View full text Add to dashboard Cite

The basic structural units of adsorbing microporous materials such as clays and cementitious materials are flexible nanolayers. The flexibility of these layers is reported to play a crucial role in the structuration of these materials, potentially affecting therefore the thermo-mechanical behavior of such materials. Adsorbed fluids are structured in a discrete number of layers within the space between the nanolayers in these materials. This discrete nature of adsorption states may lead to micro-instabilities due to non-convex energy profiles. The transition between adsorption states may involve the bending of layers. Bending contributes to metastability, which is reported to be a potential source of the irreversibilities notably in clay behavior. In this paper, we determine the bending modulus of clay nanolayers by the combination of plate theory with molecular simulations of sodium montmorillonite. The case of clays is illustrative of the behavior of phyllosilicates (i.e. sheet-silicates) which are ubiquitous minerals in the Earth's crust. We discuss the conditions in which clay particles, i.e. a stack of nanolayers, can be viewed as thin plates. Estimations of the bending modulus according to the hydration state and dimensions of clay particles are provided. We analyze the implications of the flexibility of the layers in the behavior of a stack of layers as well as in the transitions between adsorption states. The energy barrier associated with bending of clay layers and the characteristic length of bending in such transitions are provided. Our results contribute to a better understanding of the nanostructure of layered adsorbing materials.

show abstract

Section: Discussion On the Flexibility And Microtexture Of Claysmentioning

confidence: 99%

Section: Discussion On the Flexibility And Microtexture Of Claysmentioning

confidence: 99%

Section: Bending Modulus Of a Single Clay Layermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Flexibility of nanolayers and stacks: implications in the nanostructuration of clays

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Whether drops penetrate in grooves (homogeneous wetting regime: Wenzel model) or not (heterogeneous wetting regime with air trapped in between the grooves under the liquid: Cassie-Baxter model), surface roughness plays a key role in determining contact angle values. As far as clay films roughness is concerned, Zabat et al [30] reported that the nature of the interlayer ions defines the profile of the surface. They studied the roughness of montmorillonite films with various interlayer ions Li + , Na + , Cs + , Mg 2+ , Ba 2+ , Al 3+ and La 3+ by fractal analysis.…”

Section: Introductionmentioning

confidence: 99%

Effect of chemical and geometrical parameters influencing the wettability of smectite clay films

Ballah

Chamerois

Durand-Vidal

et al. 2016

Colloids and Surfaces A: Physicochemical and Engineering Aspect

View full text Add to dashboard Cite

International audienceThe wettability of three swelling clays (beidellite, nontronite and montmorillonite) exchanged with different interlayer ions (Li+, Na+, K+ and Ca2+) was investigated by using the static sessile drop method for contact angle measurements. The results show that water contact angles on clay films vary as a function of the nature of the ion with a specific behaviour of K+-exchanged clays. The effect of various parameters influencing contact angle measurements such as relative humidity (RH), particle size and surface roughness has also been examined. RH has only a limited effect on contact angles even if drop stabilisation was observed. As far as the effect of particle size is concerned, the results obtained on montmorillonite of four different sizes show that the smallest angles are obtained on films of particles of the smallest sizes for a given exchangeable ion. This is clearly linked to differences in roughness that were deduced by analysing Atomic Force Microscopy experiments. In contrast, the nature of the exchangeable cation influences roughness in the order Li+ < Na+ < K+ < Ca2+ but this order does not correspond to that deduced from the evolution of contact angles, which confirms the influence of the nature of the cation on wettability

show abstract

An implementation of impedance spectroscopy approach to predict thermoelectronic properties of elements using a connectionist model of artificial neural network

Zaoui

Belayadi

Zabat

et al. 2020

Physica B: Condensed Matter

View full text Add to dashboard Cite

Fractal analysis of surface roughness of montmorillonite clay self-supported films: Effects of exchanged cations and of mechanical tensile stress

Cited by 4 publications

References 30 publications

Flexibility of nanolayers and stacks: implications in the nanostructuration of clays

Flexibility of nanolayers and stacks: implications in the nanostructuration of clays

Effect of chemical and geometrical parameters influencing the wettability of smectite clay films

An implementation of impedance spectroscopy approach to predict thermoelectronic properties of elements using a connectionist model of artificial neural network

Contact Info

Product

Resources

About