Small-angle x-ray diffraction of Kr in mesoporous silica: Effects of microporosity and surface roughness

Hofmann, Tommy; Wallacher, Dirk; Huber, Patrick; Birringer, R.; Knorr, K.; Schreiber, Andreas; Findenegg, G. H.

doi:10.1103/physrevb.72.064122

Cited by 72 publications

(144 citation statements)

References 12 publications

Supporting

Mentioning

129

Contrasting

Order By: Relevance

“…The synthesis, hydrothermal treatment and calcination of the material followed a similar protocol to that given by Hofmann et al (2005).…”

Section: Methodsmentioning

confidence: 99%

“…Whereas pore wall deformations are difficult to measure in the case of amorphous materials (SiO 2 ), deformations of the pore lattice of ordered materials such as MCM-41 and SBA-15 can be investigated by small-angle diffraction. So far, only a few in situ sorption experiments of fluids in mesoporous materials have been conducted by X-ray (Mitropoulos et al, 1995;Albouy & Ayral, 2002;Hofmann et al, 2005;Zickler et al, 2006) and neutron diffraction (Smarsly et al, 2001;Hoinkis, 2004;Melnichenko et al, 2006). None of these were focused specifically on the effect of lattice deformations, although a slight change of the pore lattice parameter upon capillary condensation has already been noted by Albouy & Ayral (2002).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pore lattice deformation in ordered mesoporous silica studied by in situ small-angle X-ray diffraction

et al. 2007

View full text Add to dashboard Cite

Sorption and capillary condensation of an organic fluid in ordered mesoporous silica were studied by in situ small-angle X-ray diffraction using synchrotron radiation. The sorption isotherm was calculated from the sample transmission data. The diffraction peaks resulting from the periodic hexagonal arrangement of the pores show characteristic changes of intensity, position and width, and a pronounced hysteresis of these parameters in the capillary condensation/ evaporation regime was observed. The change of the peak positions with gas pressure is related to pore lattice deformations due to capillary stresses occurring at the gas-liquid phase transition.

show abstract

“…The synthesis, hydrothermal treatment and calcination of the material followed a similar protocol to that given by Hofmann et al (2005).…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Pore lattice deformation in ordered mesoporous silica studied by in situ small-angle X-ray diffraction

et al. 2007

View full text Add to dashboard Cite

show abstract

“…In template grown varieties of silica, e.g. SBA-15 17,18 , the pores are oriented all parallel, but since these samples are powders, there is again no macroscopic alignment of the pores or channels, and thus any optical anisotropies which may originate from orientational molecular ordering are washed out. A macroscopic alignment of the tubular pores does exist however for electrochemically etched mesoporous Si.…”

Section: Introductionmentioning

confidence: 99%

Liquid n-hexane condensed in silica nanochannels: A combined optical birefringence and vapor sorption isotherm study

2009

View full text Add to dashboard Cite

The optical birefringence of liquid n-hexane condensed in an array of parallel silica channels of 7 nm diameter and 400 µm length is studied as a function of filling of the channels via the vapor phase. By an analysis with the generalized Bruggeman effective medium equation we demonstrate that such measurements are insensitive to the detailed geometrical (positional) arrangement of the adsorbed liquid inside the channels. However, this technique is particularly suitable to search for any optical anisotropies and thus collective orientational order as a function of channel filling. Nevertheless, no hints for such anisotropies are found in liquid n-hexane. The n-hexane molecules in the silica nanochannels are totally orientationally disordered in all condensation regimes, in particular in the film growth as well as in the the capillary condensed regime. Thus, the peculiar molecular arrangement found upon freezing of liquid n-hexane in nanochannel-confinement, where the molecules are collectively aligned perpendicularly to the channels' long axes, does not originate in any pre-alignment effects in the nanoconfined liquid due to capillary nematization.

show abstract

“…Thus, ordered mesoporous materials are very suitable for studies of fluid adsorption. Template-grown silica and other self-ordered mesoporous substrates, such as ordered porous alumina, were intensively explored by in situ X-ray 22,[56][57][58][59][60] and neutron scattering [61][62][63] studies during adsorption of various fluids.…”

Section: B Strains On the Microscopic Scalementioning

confidence: 99%

Adsorption-induced deformation of nanoporous materials—A review

Gor

Huber

Bernstein

2017

Applied Physics Reviews

222

214

View full text Add to dashboard Cite

When a solid surface accommodates guest molecules, they induce noticeable stresses to the surface and cause its strain. Nanoporous materials have high surface area and, therefore, are very sensitive to this effect called adsorption-induced deformation. In recent years, there has been significant progress in both experimental and theoretical studies of this phenomenon, driven by the development of new materials as well as advanced experimental and modeling techniques. Also, adsorption-induced deformation has been found to manifest in numerous natural and engineering processes, e.g., drying of concrete, water-actuated movement of non-living plant tissues, change of permeation of zeolite membranes, swelling of coal and shale, etc. In this review, we summarize the most recent experimental and theoretical findings on adsorption-induced deformation and present the state-of-the-art picture of thermodynamic and mechanical aspects of this phenomenon. We also reflect on the existing challenges related both to the fundamental understanding of this phenomenon and to selected applications, e.g., in sensing and actuation, and in natural gas recovery and geological CO2 sequestration.

show abstract

Small-angle x-ray diffraction of Kr in mesoporous silica: Effects of microporosity and surface roughness

Cited by 72 publications

References 12 publications

Pore lattice deformation in ordered mesoporous silica studied by in situ small-angle X-ray diffraction

Pore lattice deformation in ordered mesoporous silica studied by in situ small-angle X-ray diffraction

Liquid n-hexane condensed in silica nanochannels: A combined optical birefringence and vapor sorption isotherm study

Adsorption-induced deformation of nanoporous materials—A review

Contact Info

Product

Resources

About