Abstract:The 3D structure of three individual aggregates composed of 165 nm polystyrene primary particles is revealed nondestructively by hard X-ray phase-contrast synchrotron nanotomography. Three-dimensional image analysis allows us for the first time to obtain the complex inner porosity of the entire aggregate. It is demonstrated that despite their rather compact structure, characterized by a fractal dimension equal to 2.7, the produced aggregates are still porous, with porosity increasing with its size. Generated p… Show more
“…S5, together with the 3D continuous approach and 3D MIP simulation plots used in the calculation, Fig. S6, according to 53 ), in agreement with the results of porosity illustrated in Fig. 6.Figure 7Pore accessibility ratio of the intra-aggregate pore space for the spherical entities.…”
Section: Resultssupporting
confidence: 82%
“…Further analysis of pore accessibility ratio was conducted applying the Pore Size Distribution (PSD) plugin 52 , implemented in Fiji 44 . The same procedure, the ratio between the constrained PSD obtained from the MIP simulations and the unconstrained PSD obtained from 3D continuous approach, as further described in 53 was applied for calculation of pore accessibility ratio. The MIP simulations were calculated using intrusion only from the side of application of consolidation agents.…”
Three synthetized polymorphs of calcium carbonate have been tested in combination with the suspension of nanolime particles as potential consolidating agents for contrasting stone decay and overcome some of the limitations of nanolime agents when applied to substrates with large porosity. The modifications induced in the pore network of the Maastricht limestone were analyzed with microscopy and in a non-invasive fashion with small angle neutron scattering and synchrotron radiation micro-computed tomography. A reduction in porosity and pore accessibility at the micrometric scale was detected with the latter technique, and ascribed to the improved pore-filling capacity of the consolidation agent containing CaCO3 particles. These were found to be effectively bound to the carbonated nanolime, strengthening the pore-matrix microstructure. Penetration depth and positive effect on porosity were found to depend on the particle size and shape. Absence of significant changes in the fractal nature of the pore surface at the nanoscale, was interpreted as indication of the negligible contribution of nanolime-based materials in the consolidation of stones with large porosity. However, the results indicate that in such cases, their effectiveness may be enhanced when used in combination with CaCO3 particles, owing to the synergic effect of chemical/structural compatibility and particle size distribution.
“…S5, together with the 3D continuous approach and 3D MIP simulation plots used in the calculation, Fig. S6, according to 53 ), in agreement with the results of porosity illustrated in Fig. 6.Figure 7Pore accessibility ratio of the intra-aggregate pore space for the spherical entities.…”
Section: Resultssupporting
confidence: 82%
“…Further analysis of pore accessibility ratio was conducted applying the Pore Size Distribution (PSD) plugin 52 , implemented in Fiji 44 . The same procedure, the ratio between the constrained PSD obtained from the MIP simulations and the unconstrained PSD obtained from 3D continuous approach, as further described in 53 was applied for calculation of pore accessibility ratio. The MIP simulations were calculated using intrusion only from the side of application of consolidation agents.…”
Three synthetized polymorphs of calcium carbonate have been tested in combination with the suspension of nanolime particles as potential consolidating agents for contrasting stone decay and overcome some of the limitations of nanolime agents when applied to substrates with large porosity. The modifications induced in the pore network of the Maastricht limestone were analyzed with microscopy and in a non-invasive fashion with small angle neutron scattering and synchrotron radiation micro-computed tomography. A reduction in porosity and pore accessibility at the micrometric scale was detected with the latter technique, and ascribed to the improved pore-filling capacity of the consolidation agent containing CaCO3 particles. These were found to be effectively bound to the carbonated nanolime, strengthening the pore-matrix microstructure. Penetration depth and positive effect on porosity were found to depend on the particle size and shape. Absence of significant changes in the fractal nature of the pore surface at the nanoscale, was interpreted as indication of the negligible contribution of nanolime-based materials in the consolidation of stones with large porosity. However, the results indicate that in such cases, their effectiveness may be enhanced when used in combination with CaCO3 particles, owing to the synergic effect of chemical/structural compatibility and particle size distribution.
“…Contrast in most computed tomography (CT) data sets depends on differences in X-ray absorption (Stock, 1999(Stock, , 2008Maire & Withers, 2014). In addition to being absorbed, X-rays are also refracted within specimens, and differences in X-ray refractive index can be the input for CT (Trtik et al, 2011;Edgecombe et al, 2012;Pfeiffer et al, 2013). These phase contrast reconstructions are useful for differentiating soft tissue types or materials with very similar absorption characteristics.…”
A model sample consisting of two different hydroxyapatite (hAp) powders was used as a bone phantom to investigate the extent to which X-ray diffraction tomography could map differences in hAp lattice constants and crystallite size. The diffraction data were collected at beamline 1-ID, the Advanced Photon Source, using monochromatic 65 keV X-radiation, a 25 x 25 microm pinhole beam and translation/rotation data collection. The diffraction pattern was reconstructed for each volume element (voxel) in the sample, and Rietveld refinement was used to determine the hAp lattice constants. The crystallite size for each voxel was also determined from the 00.2 hAp diffraction peak width. The results clearly show that differences between hAp powders could be measured with diffraction tomography
“…XPCI has been applied on porous samples using the grating-based technique at synchrotron facility and with a conventional X-ray tube [32,33]. High resolution phase-contrast tomography has been achieved using methods such as the Zernike phase-contrast method and ptychography, at synchrotron sources [34,35]. A complex refractive index was retrieved from the phase and absorption signal.…”
Abstract:The recently developed speckle-based technique is a promising candidate for laboratory-based X-ray phase-contrast imaging due to its compatibility with polychromatic X-rays, multi-modality and flexibility. Previously, successful implementations of the method on laboratory systems have been shown mostly with energies less than 20 keV on samples with materials like soft tissues or polymer. Higher energy X-rays are needed for penetrating materials with a higher atomic number or that are thicker in size. A first demonstration using high energy X-rays was recently given. Here, we present more potential application examples, i.e., a multi-contrast imaging of an IC chip and a phase tomography of a mortar sample, at an average photon energy of 40 keV using a laboratory X-ray tube. We believe the results demonstrate the applicability of this technique in a wide range of fields for non-destructive examination in industry and material science.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
