Small-angle x-ray scattering and inhomogeneities of the electron density in polycrystalline and epitaxial PbS films

1979 ◽  
Vol 22 (8) ◽  
pp. 846-851
Author(s):  
M. Ya. Fuks ◽  
P. G. Cheremskoi ◽  
O. G. Alaverdova ◽  
L. P. Shpakovskaya
Keyword(s):  
Electron Density ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Röntgenkleinwinkel-und Sedimentationsstudien am a-Häm ocyanin Helix pomatia (halbe Moleküle) in Glycerin-und Saccharoselösungen / Small-Angle X-Ray and Sedimentation Studies on a-Haemocyanin H . pomatia (Halve Molecules) in Glycerol and Sucrose Solutions Small-Angle X-Ray Scattering, Haemocyanin, Sedimentation, Multicomponent System

1976 ◽  
Vol 31 (5-6) ◽  
pp. 238-244 ◽  
Author(s):  
Johann Berger ◽  
Ingrid Pilz ◽  
Raf Witters ◽  
René Lontie
Keyword(s):  
Electron Density ◽  
Small Angle ◽  
Specific Volume ◽  
Helix Pomatia ◽  
Partial Specific Volume ◽  
Strong Increase ◽  
Radius Of Gyration ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The α -haemocyanin molecules of Helix pomatia were decomposed into halves and studied in solution by small-angle X-ray scattering. The following parameters of the molecule could be ob­tained : radius of gyration, volume, molecular weight, overall shape and dimensions of the molecule. With small-angle X-ray scattering fluctuations of the electron density within the protein cause parasitic scattering at larger angles. According to Stuhrmann and Kirste it is possible to eliminate it mathematically by varying the electron density of the buffer. For this purpose different quan­tities of glycerol respectively saccharose were added to the solvent to study the scattering of α -haemocyanin halves in solvents of varied electron density. The change of the isopotential specific volume of haemocyanin and the strong increase of the statistical errors of its scattering by de­creasing of the excess scattering of solution over solvent per unit volume did not allow an ap­plication of the method of Stuhrmann and Kirste. The data obtained for α -haemocanin halves in different solvents are given. Besides also the sedimentation of the α -haemocyanin halves were studied in solutions containing varied amounts of glycerol and saccharose. An attempt was made to calculate the change of the partial specific volume of haemocyanin by adding glycerol or saccharose.

Nanoparticle characterization by continuous contrast variation in small-angle X-ray scattering with a solvent density gradient

2015 ◽  
Vol 48 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Raul Garcia-Diez ◽  
Christian Gollwitzer ◽  
Michael Krumrey
Keyword(s):  
Density Gradient ◽  
Electron Density ◽  
Small Angle ◽  
Glass Capillary ◽  
Contrast Variation ◽  
X Ray ◽  
X Ray Scattering ◽  
Novel Approach ◽  
Solvent Density ◽  
Ray Scattering

Many low-density nanoparticles show a radial inner structure. This work proposes a novel approach to contrast variation with small-angle X-ray scattering based on the constitution of a solvent density gradient in a glass capillary in order to resolve this internal morphology. Scattering curves of a polymeric core–shell colloid were recorded at different suspending medium contrasts at the four-crystal monochromator beamline of PTB at the synchrotron radiation facility BESSY II. The mean size and size distribution of the particles as well as an insight into the colloid electron density composition were determined using the position of the isoscattering points in the Fourier region of the scattering curves and by examining the Guinier region in detail. These results were corroborated with a model fit to the experimental data, which provided complementary information about the inner electron density distribution of the suspended nanoparticles.

scholarly journals Electron density map using multiple scattering in grazing-incidence small-angle X-ray scattering

2007 ◽  
Vol 40 (3) ◽  
pp. 496-504 ◽  
Author(s):  
Byeongdu Lee ◽  
Insun Park ◽  
Haewoong Park ◽  
Chieh-Tsung Lo ◽  
Taihyun Chang, ◽  
...  
Keyword(s):  
Multiple Scattering ◽  
Electron Density ◽  
Small Angle ◽  
Grazing Incidence ◽  
X Ray ◽  
X Ray Scattering ◽  
Diffraction Peaks ◽  
Density Map ◽  
Electron Density Map ◽  
Ray Scattering

The electron density map of a block copolymer thin film having the hexagonally perforated layer (HPL) structure was directly obtained from the measured grazing-incidence small-angle X-ray scattering (GISAXS) pattern, exploiting the multiple-scattering phenomena present in GISAXS. It is shown that GISAXS is in principle equivalent to three-beam diffraction, which has been used to extract phases of diffraction peaks. In addition, X-ray reflectivity analysis has been performed which, when combined with the GISAXS results, provides full details of the HPL structure.

Small-angle X-ray scattering investigation of the micellar and submicellar forms of bovine casein

1989 ◽  
Vol 56 (3) ◽  
pp. 443-451 ◽  
Author(s):  
Helmut Pessen ◽  
Thomas F. Kumosinski ◽  
Harold M. Farrell
Keyword(s):  
Electron Density ◽  
Small Angle ◽  
Distribution Functions ◽  
Spherical Particles ◽  
Scattering Data ◽  
Cross Sectional ◽  
Packing Number ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

SummarySmall-angle X-ray scattering was performed on whole casein under submicellar (Ca2+ removed) and micellar (Ca2+ re-added) conditions. Submicellar scattering curves showed two Gaussian components which were interpreted in terms of a spherical particle with two concentric regions of different electron density, a relatively compact core of higher electron density and a looser shell. Normalized scattering curves and calculated distance distribution functions were consistent with this picture. Micellar scattering data, which can yield only cross-sectional information related to a window of scattered intensities, could be analysed by a sum of three Gaussians with no residual function. The two Gaussians with the lower radii of gyration were again taken to indicate the two concentric regions of different electron density of inhomogeneous spherical particles; the third Gaussian was shown to reflect the packing number of these particles within a cross-sectional portion of the micelle, which was 3:1 for this system. These results are a strong indication that submicellar inhomogeneous particles containing hydrophobically stabilized inner cores exist within the colloidal micelle.

Structural Characterization of a Telechelic Ionomer at Various Degrees of Neutralization

1997 ◽  
Vol 30 (5) ◽  
pp. 717-721 ◽  
Author(s):  
D. R. S. Bittencourt ◽  
P. Charier ◽  
R. Jérôme ◽  
C. E. Williams
Keyword(s):  
Electron Density ◽  
Structural Characterization ◽  
Small Angle ◽  
Functional Form ◽  
Quality Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Good Quality Data ◽  
Ray Scattering

The morphology of sodium-neutralized carboxytelechelic ionomers has been characterized by SAXS (small-angle X-ray scattering) for varying degrees of neutralization between 20 and 100%. The good-quality data covering a broad q range have been fitted with a functional form of the intensity. It has been found that the aggregates grow as more chain ends are neutralized while the electron density is kept constant, in agreement with the multiplet model. The excess scattering at small angles was found to vary systematically with the degree of neutralization, confirming the ionic origin of this feature.

BILMIX: a new approach to restore the size polydispersity and electron density profiles of lipid bilayers from liposomes using small-angle X-ray scattering data

2020 ◽  
Vol 53 (1) ◽  
pp. 236-243
Author(s):  
Petr V. Konarev ◽  
Maxim V. Petoukhov ◽  
Liubov A. Dadinova ◽  
Natalia V. Fedorova ◽  
Pavel E. Volynsky ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Electron Density ◽  
Lipid Bilayers ◽  
Density Profile ◽  
Small Angle ◽  
Electron Density Profile ◽  
Scattering Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Small-angle X-ray scattering (SAXS) is one of the major tools for the study of model membranes, but interpretation of the scattering data remains non-trivial. Current approaches allow the extraction of some structural parameters and the electron density profile of lipid bilayers. Here it is demonstrated that parametric modelling can be employed to determine the polydispersity of spherical or ellipsoidal vesicles and describe the electron density profile across the lipid bilayer. This approach is implemented in the computer program BILMIX. BILMIX delivers a description of the electron density of a lipid bilayer from SAXS data and simultaneously generates the corresponding size distribution of the unilamellar lipid vesicles.

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