Microstructure of a Slag-Cement Paste Determined by Small-Angle Neutron Scattering

1997 ◽  
Vol 506 ◽  
Author(s):  
L.P. Aldridge ◽  
W.K. Bertram ◽  
T.M. Sabine ◽  
A Ioffe

ABSTRACTSmall angle neutron scattering from hydrating cement paste was compared to that from a paste made of a blend of cement and ground granulated blast furnace slag. The scattering measurements were used to determine the average size of the scattering particles during hydration. Their rate of growth was monitored in-situ over the first 40 hours of hydration. There was little difference in the scattering spectra, showing that the scattering particles in paste containing slag blend or cement were of similar size. At the beginning of hydration the particle radii were about 250 nn and after 14 days they had grown to over 600nm.Estimates of particle sizes are critically dependent on the amount of multiple scattering. Therefore the amount of multiple scattering of the sample must be taken into account before making comparisons between the sizes of particles of different matrices.

1997 ◽  
Vol 30 (5) ◽  
pp. 602-606 ◽  
Author(s):  
G. Albertini ◽  
F. Carsughi ◽  
R. Coppola ◽  
R. K. Heenan ◽  
M. Stefanon

Two different small-angle neutron scattering (SANS) facilities, the D11 camera at the Institut Laue–Langevin (ILL, Grenoble, France) and the LOQ time-of-flight diffractometer at the Rutherford Appleton Laboratory (RAL, Didcot, Oxon, England), were used in the investigations of δ′-Al3Li precipitation at 463 K in Al–Li 3% alloy. The results obtained from the steady-state reactor and from the pulsed source by using two different data-acquisition techniques and two different procedures for data analysis are compared. The SANS curves for the same set of samples investigated using the two different instruments are in good agreement within the experimental uncertainties. A check was also made on the metallurgically relevant quantities, namely the average size and the size-distribution function of the δ′ precipitates at the various stages of the ageing process, obtained from the two sets of SANS curves by applying the same numerical method. Good agreement was found between the results from the two data sets.


1985 ◽  
Vol 18 (6) ◽  
pp. 467-472 ◽  
Author(s):  
N. F. Berk ◽  
K. A. Hardman-Rhyne

Microstructural parameters of high-purity alumina powder are determined quantitatively throughout the bulk of the material using small-angle neutron scattering techniques. A unified theoretical and experimental approach for analyzing multiple scattering data is developed to obtain values for particle size, volume fraction and surface area. It is shown how particle size and volume fraction can be measured in a practical way from SANS data totally dominated by incoherent multiple scattering (`beam broadening'). The general phase-shift dependence of single-particle scattering is incorporated into the multiple scattering formalism, and it is also shown that the diffractive limit (small phase shift) applies even for phase shifts as large as unity (particle radii of order 1 μm). The stability of the Porod law against multiple scattering and the phase-shift scale are described, a useful empirical formula for analysis of beam broadening data is exhibited, and the applicability of the formulations to polydispersed systems is discussed.


Carbon ◽  
2013 ◽  
Vol 57 ◽  
pp. 460-469 ◽  
Author(s):  
Félix Balima ◽  
Vittoria Pischedda ◽  
Sylvie Le Floch ◽  
Annie Brûlet ◽  
Peter Lindner ◽  
...  

Langmuir ◽  
2019 ◽  
Vol 35 (10) ◽  
pp. 3822-3831 ◽  
Author(s):  
Ignacio Martín-Fabiani ◽  
David K. Makepeace ◽  
Philip G. Richardson ◽  
Jennifer Lesage de la Haye ◽  
Diego Alba Venero ◽  
...  

2011 ◽  
Vol 1334 ◽  
Author(s):  
Dipendu Saha ◽  
Lilin He ◽  
Cristian I. Contescu ◽  
Nidia C. Gallego ◽  
Yuri B. Melnichenko

ABSTRACTEntrapping hydrogen molecules within the nanopores of solid adsorbents serves as a unique alternative for on-board storing of hydrogen for transportation purposes. The key advantage of the physisorption process for hydrogen storage is the higher density values achieved with the adsorbed gas, compared to that of the compressed phase, translating into higher storage capacities at lower pressures. The necessary condition for effective adsorption is the presence of narrow micropores of < 2 nm in width which provide the most suitable environment of hydrogen adsorption. Despite numerous theoretical calculations or indirect experimental estimations, there has not been a direct experimental measurement of the density of adsorbed hydrogen as a function of pressure and/or pore size. In the present study, we report on the use of in-situ small angle neutron scattering (SANS) to study the phase behavior of hydrogen confined in narrow micropores. We provide for the first time direct experimental measurements of the effect of pore size and pressure on hydrogen adsorbed on a polyfurfuryl alcohol-derived activated carbon (PFAC), at room temperature and pressures up to 207 bar. SANS studies were carried out at the General-Purpose Small-Angle Neutron Scattering spectrometer of the High Flux Isotope Reactor at Oak Ridge National Laboratory. The measurements covered the Q-range from 0.01 to 0.8 Å-1, covering the pores in the range of 9 to 34 Å of the PFAC material. Initial results suggest that the density of adsorbed hydrogen is higher than the density of bulk hydrogen gas and increases with decreasing pore size.


2011 ◽  
Vol 110 (10) ◽  
pp. 102217 ◽  
Author(s):  
Andrey V. Ilatovskiy ◽  
Dmitry V. Lebedev ◽  
Michael V. Filatov ◽  
Mikhail Grigoriev ◽  
Michael G. Petukhov ◽  
...  

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