Structural Investigation of a Surfactant-Templated Silica Aerogel by Small-angle Scattering

1998 ◽  
Vol 520 ◽  
Author(s):  
Thomas P. Riekerlt ◽  
Mark T. Anderson ◽  
Patricia S. Sawyer ◽  
Shrish Rane ◽  
Gregory Beaucage
Keyword(s):  
Light Scattering ◽  
Small Angle ◽  
Silica Aerogel ◽  
Large Scale ◽  
Structural Investigation ◽  
Structural Information ◽  
Structural Features ◽  
Length Scales ◽  
X Ray ◽  
Angle Scattering

ABSTRACTThe structure of a surfactant-templated silica aerogel is studied by small-angle x-ray and light scattering. By combining the two techniques, we obtain structural information on length scales from Ångstroms to 0.1 millimeters. For this sample, we find five structural features, including the morphology of large scale aggregates.

Information retrieval from X-ray small-angle scattering with polychromatic (`white') synchrotron radiation

1983 ◽  
Vol 16 (1) ◽  
pp. 42-46 ◽  
Author(s):  
O. Glatter ◽  
P. Laggner
Keyword(s):  
Synchrotron Radiation ◽  
Small Angle ◽  
Particle Shape ◽  
Structural Information ◽  
Small Angle Scattering ◽  
Radius Of Gyration ◽  
X Ray ◽  
Angle Scattering ◽  
Slit Length ◽  
Hinge Bending

The possibilities of obtaining structural information from X-ray small-angle scattering experiments with `white' polychromatic synchrotron radiation using line collimation are investigated by numerical simulation. Theoretical scattering curves of geometrical models were smeared with the appropriate wavelength distributions and slit-length functions, afflicted by statistical noise, and then evaluated by identical methods as normally used for experimental data, as described previously [program ITP; Glatter (1977). J. Appl. Cryst. 10, 415–421]. It is shown that even for a wavelength distribution of 50% half width, the information content is not limited to the parameters derived from the central part of the scattering curves, i.e. the radius of gyration and the zero-angle intensity, but also allows qualitative information on particle shape via the distance distribution function p(r). By a `hinge-bending model' consisting of two cylinders linked together at different angles it is demonstrated that changes in the radius of gyration amounting to less than 5% can be detected and quantified, and the qualitative changes in particle shape be reproduced.

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.

scholarly journals Structure of PEP–PEO block copolymer micelles: exploiting the complementarity of small-angle X-ray scattering and static light scattering

2011 ◽  
Vol 44 (3) ◽  
pp. 473-482 ◽  
Author(s):  
Grethe Vestergaard Jensen ◽  
Qing Shi ◽  
María J. Hernansanz ◽  
Cristiano L. P. Oliveira ◽  
G. Roshan Deen ◽  
...  
Keyword(s):  
Light Scattering ◽  
Block Copolymer ◽  
Small Angle ◽  
Static Light Scattering ◽  
Length Scales ◽  
X Ray ◽  
X Ray Scattering ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Poly Ethylene

The structure of large block copolymer micelles is traditionally determined by small-angle neutron scattering (SANS), covering a large range of scattering vectors and employing contrast variation to determine the overall micelle morphology as well as the internal structure on shorter length scales. The present work shows that the same information can be obtained by combining static light scattering (SLS) and small-angle X-ray scattering (SAXS), which provide information on, respectively, large and short length scales. Micelles of a series of block copolymers of poly(ethylene propylene)-b-poly(ethylene oxide) (PEP–PEO) in a 70% ethanol solution are investigated. The polymers have identical PEP blocks of 5.0 kDa and varying PEO blocks of 2.8–49 kDa. The SLS contrasts of PEP and PEO are similar, providing a homogeneous contrast, making SLS ideal for determining the overall micelle morphology. The SAXS contrasts of the two components are very different, allowing for resolution of the internal micelle structure. A core–shell model with a PEP core and PEO corona is fitted simultaneously to the SAXS and SLS data using the different contrasts of the two blocks for each technique. With increasing PEO molecular weight, a transition from cylindrical to spherical micelles is observed. This transition cannot be identified from the SAXS data alone, but only from the SLS data.

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.

Examples of Biological Small Angle Scattering

2018 ◽  
Author(s):  
Eaton E. Lattman ◽  
Thomas D. Grant ◽  
Edward H. Snell
Keyword(s):  
Small Angle ◽  
Large Scale ◽  
Structural Information ◽  
Small Angle Scattering ◽  
Solution Technique ◽  
Time Resolved ◽  
Functional Changes ◽  
Angle Scattering ◽  
Access Information ◽  
Contrast Matching

In this chapter we illustrate the biological applications of small angle scattering. We cover examples of contrast matching has been used in the neutron case and with SAXS,. time-resolved studies that have helped reveal mechanism and how SAXS or SANS as a solution technique can access information missing from other studies, in particular residues that may be crystallographically undefined. We show examples of puting known structural information in context, and following large-scale functional changes or show when distinct populations co-exist in solution. The list of examples provided is not exhaustive and should be seen as a glimpse of the potential of biological mechanisms where SAXS or SANS can provide unique information complementary to other methods and help define function and mechanism.

Determination of micrometer length scales with an X-ray reflection ultra small-angle scattering set-up

1998 ◽  
Vol 42 (5) ◽  
pp. 517-522 ◽  
Author(s):  
P Müller-Buschbaum ◽  
M Casagrande ◽  
J Gutmann ◽  
T Kuhlmann ◽  
M Stamm ◽  
...  
Keyword(s):  
Small Angle ◽  
Small Angle Scattering ◽  
Length Scales ◽  
X Ray ◽  
Angle Scattering ◽  
Set Up

scholarly journals MATSAS: a small-angle scattering computing tool for porous systems

2021 ◽  
Vol 54 (2) ◽  
Author(s):  
Amirsaman Rezaeyan ◽  
Vitaliy Pipich ◽  
Andreas Busch
Keyword(s):  
Small Angle ◽  
Structural Information ◽  
Fractal Dimensions ◽  
Small Angle Scattering ◽  
Scattering Data ◽  
Porous System ◽  
X Ray ◽  
Matlab Program ◽  
Angle Scattering ◽  
Neutron Small Angle Scattering

MATSAS is a script-based MATLAB program for analysis of X-ray and neutron small-angle scattering (SAS) data obtained from various facilities. The program has primarily been developed for sedimentary rock samples but is equally applicable to other porous media. MATSAS imports raw SAS data from .xls(x) or .csv files, combines small-angle and very small angle scattering data, subtracts the sample background, and displays the processed scattering curves in log–log plots. MATSAS uses the polydisperse spherical (PDSP) model to obtain structural information on the scatterers (scattering objects); for a porous system, the results include specific surface area (SSA), porosity (Φ), and differential and logarithmic differential pore area/volume distributions. In addition, pore and surface fractal dimensions (D p and D s, respectively) are obtained from the scattering profiles. The program package allows simultaneous and rapid analysis of a batch of samples, and the results are then exported to .xlsx and .csv files with separate spreadsheets for individual samples. MATSAS is the first SAS program that delivers a full suite of pore characterizations for sedimentary rocks. MATSAS is an open-source package and is freely available at GitHub (https://github.com/matsas-software/MATSAS).

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