Small-angle neutron scattering from a nano-layered synthetic silicate

Knudsen, Kenneth D.; Fossum, Jon Otto; Helgesen, Geir; Haakestad, Magnus W.

doi:10.1016/j.physb.2004.07.018

Cited by 28 publications

(26 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This length should be attributed to a typical pore size in the direction of the applied pressure. Particles present, on average, their lateral side to the beam, with their thickness along the horizontal direction; consequently, the pores resulting from particle aggregation exhibit a large aspect ratio: their smallest dimension is found along that direction (Knudsen et al, 2004). The average thickness typical of these clay particles in suspension (around 100 nm) is itself out of our data range.…”

Section: Anisotropy Of the Saxs Images:mentioning

confidence: 63%

“…The global porosity of the samples (i.e. the ratio of the pore volume to the total volume) was measured to be 50% (Knudsen et al, 2004). The clay disks were then cut into 2 Â 2 Â 6 mm 3 parallelepipedic slices, proper for synchrotron experiments.…”

Section: Orientation Distribution Probability Functions Of Platelet-smentioning

confidence: 99%

“…In this paper, we also investigate the changes in the geometry of the whole weakly hydrated assembly under the effect of individual particle swelling, but using small-angle X-ray scattering (SAXS), thus probing larger length scales. Note that small-angle neutron scattering has previously been used on similar samples, focusing on typical pore sizes (Knudsen et al, 2004). Here we address predominantly orientational order.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mesoscopic structure of dry-pressed clay samples from small-angle X-ray scattering measurements

et al. 2007

View full text Add to dashboard Cite

Weakly hydrated samples of platelet‐shaped nano‐particles obtained by dry‐pressing suspensions of the synthetic Na fluorohectorite clay are studied. The particles consist of stacks of several tens of 1 nm‐thick nanosilicate platelets. They form a compound of quasi‐two‐dimensional particles whose average director is aligned with the direction of the uniaxial stress applied at dehydration. Small‐angle X‐ray scattering images from these samples are either isotropic or anisotropic, depending on the sample orientation with respect to the X‐ray beam. From anisotropic images, changes in the scattering objects' orientation distribution probability (ODP) function are investigated as the temperature is lowered, thus triggering swelling of the individual particles by water intercalation. This is done, on the one hand, by inferring the width of the ODP function from the eccentricity of quasi‐elliptic iso‐intensity cuts of the small‐angle scattering images, and, on the other hand, by obtaining the ODP function from azimuthal profiles of the images. The decays of the scattering intensity as a function of momentum transfer along the two principal directions of the images exhibit power law behaviors. A crossover scale between two power law regimes is observed on the profiles recorded along the horizontal axis; it corresponds to the typical pore size along the direction of the initially applied load. These results are compared with a previous study of similar systems.

show abstract

Section: Anisotropy Of the Saxs Images:mentioning

confidence: 63%

Section: Orientation Distribution Probability Functions Of Platelet-smentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mesoscopic structure of dry-pressed clay samples from small-angle X-ray scattering measurements

et al. 2007

View full text Add to dashboard Cite

show abstract

“…In Na-FH the polar water molecules will intercalate the clay mineral nanostructure [18][19][20], in addition to adhering to the outer clay mineral particle surfaces.…”

Section: Effects Of Watermentioning

confidence: 99%

Electric Alignment of Plate Shaped Clay Aggregates in Oils

et al. 2016

View full text Add to dashboard Cite

We experimentally investigate the rotation of plate shaped aggregates of clay mineral particles immersed in silicone oil. The rotation is induced by an external electric field. The rotation time is measured as a function of the following parameters: electric field strength, the plate geometry (length and width) and the dielectric properties of the plates. We find that the plates always align with their longest axis parallel to the direction of the electric field (E), independently of the arrangement of individual clay mineral particles within the plate. The rotation time is found to scale as E −2 and is proportional to the viscosity (η), which coincides well with a model that describes orientation of dipoles in electric fields. As the length of the plate is increased we quantify a difference between the longitudinal and transverse polarizability. Finally, we show that moist plates align faster. We attribute this to the change of the dielectric properties of the plate due to the presence of water.

show abstract

“…When polarizable particles are exposed to an E-field of either alternating-current (AC) or direct-current (DC), dipoles will be induced and result in a rotational force on the particles in accordance with the Clausius-Mossotti relation [10]. The particle alignment can be monitored by means of X-ray or neutron diffraction [11,12], and the degree of anisotropy can be quantified and expressed in terms of an order parameter S 2 [7,13] (for details see Section 3.3).…”

Section: Introductionmentioning

confidence: 99%

Electric field nematic alignment of fluorohectorite clay particles in oligomeric matrices

et al. 2013

View full text Add to dashboard Cite

We study the behaviour of fluorohectorite synthetic clay particles dispersed in paraffin-wax. First, we report wide angle X-ray scattering related to electric-field-induced alignment of the embedded clay particles. Secondly, we provide observations of system anisotropy during melting and crystallization of clay/paraffin nanocomposites. Finally, the time evolution of the one-to-zero/zero-to-one water layer transition in paraffin embedded fluorohectorite clay galleries is presented, and we demonstrate that such particles can be used as 'meso-detectors' for monitoring the local water content in bulk carrier matrices, such as paraffin-wax.

show abstract

Small-angle neutron scattering from a nano-layered synthetic silicate

Cited by 28 publications

References 24 publications

Mesoscopic structure of dry-pressed clay samples from small-angle X-ray scattering measurements

Mesoscopic structure of dry-pressed clay samples from small-angle X-ray scattering measurements

Electric Alignment of Plate Shaped Clay Aggregates in Oils

Electric field nematic alignment of fluorohectorite clay particles in oligomeric matrices

Contact Info

Product

Resources

About