Small-angle X-ray scattering by PVP–water mixtures

2001 ◽  
Vol 34 (1) ◽  
pp. 62-64 ◽  
Author(s):  
Jan van der Elsken ◽  
Wim Bras ◽  
Jan Michielsen
Keyword(s):  
Small Angle ◽  
Large Scale ◽  
Columnar Structure ◽  
Water Mixture ◽  
X Ray ◽  
Large Scale Structures ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Hexagonal Columnar ◽  
Ray Scattering

Small-angle X-ray scattering experiments reveal the formation of large-scale structures when a 60 wt% poly(vinylpyrrolidone) (PVP)–water mixture is cooled to 260 K. The formation of these structures leads to an enhancement of continuous small-angle scattering with decreasing temperature. This is accompanied by the appearance of sharp Bragg peaks that have a very short lifetime. The scattering angles of these peaks are in accordance with a hexagonal columnar structure. It appears that such structures occasionally live long enough to undergo rotational Brownian motion.

The nature of the scattering tail in Cu–Ni–Fe and Invar alloys investigated by anomalous small-angle X-ray scattering

1991 ◽  
Vol 24 (6) ◽  
pp. 1027-1034 ◽  
Author(s):  
J. P. Simon ◽  
O. Lyon
Keyword(s):  
Small Angle ◽  
Large Scale ◽  
Concentration Fluctuations ◽  
X Ray ◽  
Invar Alloys ◽  
X Ray Scattering ◽  
Angle Measurements ◽  
Two Systems ◽  
Fe Alloys ◽  
Ray Scattering

A large rapidly decreasing intensity called the `scattering tail' is generally observed at the smallest recorded angles during small-angle measurements of metallic alloys. Since this tail was interpreted as caused by a bimodal phase separation in Cu–Ni–Fe alloys and by long-wavelength concentration fluctuations in Invar alloys, these two systems were re-examined with anomalous X-ray scattering. The variation of the alloying atomic contrasts allows a discrimination between the different types of particles or defects. In neither of the two systems can the tails be interpreted as caused by large-scale concentration fluctuations. In Cu–Ni–Fe alloys, the tail is due to some kind of superficial defect (surface roughness etc.). In Invar alloys, the tail is probably due to residual impurity particles.

Small-angle X-ray scattering study on correlation length and density fluctuations in a supercritical CO2–water mixture

2002 ◽  
Vol 198 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Jianling Zhang ◽  
Juncheng Liu ◽  
Liang Gao ◽  
Xiaogang Zhang ◽  
Zhenshan Hou ◽  
...  
Keyword(s):  
Correlation Length ◽  
Small Angle ◽  
Supercritical Co2 ◽  
Density Fluctuations ◽  
Water Mixture ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Small-Angle X-ray Scattering Study of Nanocrystalline and Amorphous States of the Fe73.5CuNb3Si13.5B9 Alloy

1997 ◽  
Vol 30 (5) ◽  
pp. 633-636 ◽  
Author(s):  
D. R. dos Santos ◽  
I. L. Torriani ◽  
A. Y. Ramos ◽  
M. Knobel
Keyword(s):  
Small Angle ◽  
Melt Spinning ◽  
Structural Evolution ◽  
Atomic Diffusion ◽  
X Ray ◽  
X Ray Scattering ◽  
Nanocrystalline And Amorphous ◽  
Angle Scattering ◽  
Amorphous States ◽  
Ray Scattering

The structural evolution of the nanocrystalline material obtained from the amorphous compound Fe73.5CuNb3Si13.5B9 was investigated by small-angle X-ray scattering. Four sets of amorphous metallic ribbons were produced by melt spinning using different quenching rates. Samples of each set were annealed above the crystallization temperature; X-ray diffraction analysis showed the formation of an ordered Fe–Si solid solution with average grain sizes ranging from 9 to 11 nm. Small-angle scattering curves of the samples in the initial amorphous states revealed different intensities for different quenching rates, caused by the presence of heterogeneities with dimensions larger than those of the crystallites formed after thermal treatment. In addition, scattering measurements carried out in situ during isothermal annealing showed an intensity evolution as a function of time, attributed to electron-density contrast variation caused by the atomic diffusion process that occurs during crystallization.

scholarly journals Two practical Java software tools for small-angle X-ray scattering analysis of biomolecules

2014 ◽  
Vol 47 (2) ◽  
pp. 810-815 ◽  
Author(s):  
Andreas Hofmann ◽  
Andrew E. Whitten
Keyword(s):  
Small Angle ◽  
Three Dimensional ◽  
Small Angle Scattering ◽  
Ease Of Use ◽  
Scattering Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Three Dimensional Models ◽  
Ray Scattering

Small-angle X-ray scattering has established itself as a common technique in structural biology research. Here, two novel Java applications to aid modelling of three-dimensional macromolecular structures based on small-angle scattering data are described.MolScatis an application that computes small-angle scattering intensities from user-provided three-dimensional models. The program can fit the theoretical scattering intensities to experimental X-ray scattering data.SAFIRis a program for interactive rigid-body modelling into low-resolution shapes restored from small-angle scattering data. The program has been designed with an emphasis on ease of use and intuitive handling. An embedded version ofMolScatis used to enable quick evaluation of the fit between the model and experimental scattering data.SAFIRalso provides options to refine macromolecular complexes with optional user-specified restraints against scattering data by means of a Monte Carlo approach.

Small-angle energy-dispersive X-ray scattering using a laboratory-based diffractometer with a conventional source

2007 ◽  
Vol 40 (2) ◽  
pp. 218-231 ◽  
Author(s):  
Giuseppe Portale ◽  
Alessandro Longo ◽  
Lucio D'Ilario ◽  
Andrea Martinelli ◽  
Ruggero Caminiti ◽  
...  
Keyword(s):  
Small Angle ◽  
Energy Dispersive ◽  
Protein Solutions ◽  
X Rays ◽  
Catalytic Systems ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Ray Patterns ◽  
Ray Scattering

The use of polychromaticBremsstrahlungX-rays generated by commercial tubes for energy-dispersive small-angle scattering measurements has not been extensively discussed in the literature, mainly because of some difficulties associated with it. If a suitable experimental setup is chosen and concomitant phenomena are taken into account for correcting the observed X-ray patterns, energy-dispersive small-angle X-ray scattering (SAXS) may become an interesting alternative to conventional measurements based on monochromatic beams. Energy-dispersive SAXS experiments carried out on protein solutions, micelles, semicrystalline polymers and catalytic systems are discussed to illustrate the new opportunities offered by this technique as well as its limitations.

First performance assessment of the small-angle X-ray scattering beamline at ELETTRA

1998 ◽  
Vol 5 (3) ◽  
pp. 506-508 ◽  
Author(s):  
H. Amenitsch ◽  
M. Rappolt ◽  
M. Kriechbaum ◽  
H. Mio ◽  
P. Laggner ◽  
...  
Keyword(s):  
Small Angle ◽  
Wide Angle ◽  
Fibrous Materials ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Scattering Measurements ◽  
Double Focusing ◽  
Ray Scattering

The double-focusing high-flux wiggler beamline dedicated to small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) at ELETTRA has gone into user operation recently. It has been designed specifically for time-resolved studies of non-crystalline and fibrous materials in the submillisecond time scale, and has been optimized for small-angle scattering measurements. An overview of the beamline status and of some representative results, highlighting the performance of the SAXS beamline, are given.

Nanostructure of a-Si:H and Related Materials by Small-Angle X-Ray Scattering

1995 ◽  
Vol 377 ◽  
Author(s):  
D. L. Williamson
Keyword(s):  
Small Angle ◽  
Detailed Comparison ◽  
Small Angle Scattering ◽  
Atomic Scale ◽  
X Ray ◽  
X Ray Scattering ◽  
Current State ◽  
Angle Scattering ◽  
Wide Range ◽  
Ray Scattering

ABSTRACTThe use of small-angle x-ray scattering to examine nanostructural features of a-Si:H and the related alloys a-SiGe:H and a-SiC:H will be reviewed. A wide range of H, Ge, and C compositions has been investigated. The films examined came from several film- and device-making groups and represent current state-of-the-art solar cell material or attempts to develop improved and more stable material. A detailed comparison of the three classes of materials reveals dramatic differences in nanostructure. The diffuse component of the small-angle scattering, not recognized or discussed in previous small-angle scattering experiments on these materials by other groups, is shown to contain potentially valuable information on the atomic-scale structure.

Upgraded SSRF BL19U2 beamline for small-angle X-ray scattering of biological macromolecules in solution

2018 ◽  
Vol 51 (6) ◽  
pp. 1633-1640 ◽  
Author(s):  
Guangfeng Liu ◽  
Yiwen Li ◽  
Hongjin Wu ◽  
Xibo Wu ◽  
Xianhui Xu ◽  
...  
Keyword(s):  
Small Angle ◽  
Structural Information ◽  
Biological Macromolecules ◽  
Shanghai Synchrotron Radiation Facility ◽  
X Ray ◽  
Structure Information ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Short Period ◽  
Ray Scattering

The biological small-angle X-ray scattering (BioSAXS) beamline (BL19U2) at the Shanghai Synchrotron Radiation Facility, China, is dedicated exclusively to small-angle scattering experiments for biological macromolecules in solution. With recent advances in data-analysis algorithms and X-ray detectors, SAXS becomes an ideal complementary technique to other structural and biophysical methods, but it can also be applied alone to obtain important structural information. Owing to the increasing interest in solution scattering studies from the biological community, the workload on BL19U2 has steadily risen. A major upgrade of BL19U2 was performed to improve the beamline data quality, to enrich the possible sample environments and to provide a user-friendly interface. These upgrades involved the major components of BL19U2, including the optical system (slits, beamstop), the electronics, the control and acquisition software, and the sample environments, which resulted in improvements to the collected angular range in BL19U2. These upgrades have significantly broadened the scope of macromolecule size (from kilodaltons to gigadaltons) analysed at the beamline. The dedicated BL19U2 BioSAXS beamline now offers fully automated data-collection and remote-control possibilities. These developments have paved the way for high-throughput studies that generate significant quantities of structure information over a short period of time.

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