scholarly journals Estimation of the molecular weight of nanoparticles using a single small-angle X-ray scattering measurement on a relative scale

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Zhigunov ◽  
Josef Pleštil
Keyword(s):  
Molecular Weight ◽  
Small Angle ◽  
Single Scattering ◽  
X Rays ◽  
Additional Information ◽  
X Ray Scattering ◽  
Step Procedure ◽  
Angle Scattering ◽  
Relative Scale

AbstractBoth small-angle scattering methods, X-rays (SAXS) and neutrons (SANS) rank among the methods that facilitate the determination of the molar mass of nanoparticles. Using this measure, aggregation or degradation processes are easy to follow. Mono- and multichain assemblies of nanoparticles in solution could be resolved, swelling ratio can also be obtained. In this work, we present a method that allows extraction of additional information, including molecular weight, from a single scattering curve, even on a relative scale. The underlying theory and step-by-step procedure are described.

scholarly journals Stable DOPG/Glycyrrhizin Vesicles with a Wide Range of Mixing Ratios: Structure and Stability as Seen by Scattering Experiments and Cryo-TEM

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4959
Author(s):  
Carina Dargel ◽  
Friederike Gräbitz-Bräuer ◽  
Ramsia Geisler ◽  
Pascal Fandrich ◽  
Yvonne Hannappel ◽  
...  
Keyword(s):  
Small Angle ◽  
Small Angle Scattering ◽  
Scattering Data ◽  
X Rays ◽  
Additional Information ◽  
Mixing Ratios ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Wide Range ◽  
Complete Miscibility

Phosphatidylglycerols represent a large share of the lipids in the plasmamembrane of procaryotes. Therefore, this study investigates the role of charged lipids in the plasma membrane with respect to the interaction of the antiviral saponin glycyrrhizin with such membranes. Glycyrrhizin is a natural triterpenic-based surfactant found in licorice. Vesicles made of 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1’-glycerol) (DOPG)/glycyrrhizin are characterized by small-angle scattering with neutrons and X-rays (SANS and SAXS). Small-angle scattering data are first evaluated by the model-independent modified Kratky–Porod method and afterwards fitted by a model describing the shape of small unilamellar vesicles (SUV) with an internal head-tail contrast. Complete miscibility of DOPG and glycyrrhizin was revealed even at a ratio of lipid:saponin of 1:1. Additional information about the chain-chain correlation distance of the lipid/saponin mixtures in the SUV structures is obtained from wide-angle X-ray scattering (WAXS).

Determination of the molecular weight of proteins in solution from a single small-angle X-ray scattering measurement on a relative scale

2009 ◽  
Vol 43 (1) ◽  
pp. 101-109 ◽  
Author(s):  
H. Fischer ◽  
M. de Oliveira Neto ◽  
H. B. Napolitano ◽  
I. Polikarpov ◽  
A. F. Craievich
Keyword(s):  
Molecular Weight ◽  
Small Angle ◽  
Dilute Solution ◽  
X Ray ◽  
Molecular Weights ◽  
X Ray Scattering ◽  
Saxs Curve ◽  
Relative Scale ◽  
Ray Scattering

This paper describes a new and simple method to determine the molecular weight of proteins in dilute solution, with an error smaller than ∼10%, by using the experimental data of a single small-angle X-ray scattering (SAXS) curve measured on a relative scale. This procedure does not require the measurement of SAXS intensity on an absolute scale and does not involve a comparison with another SAXS curve determined from a known standard protein. The proposed procedure can be applied to monodisperse systems of proteins in dilute solution, either in monomeric or multimeric state, and it has been successfully tested on SAXS data experimentally determined for proteins with known molecular weights. It is shown here that the molecular weights determined by this procedure deviate from the known values by less than 10% in each case and the average error for the test set of 21 proteins was 5.3%. Importantly, this method allows for an unambiguous determination of the multimeric state of proteins with known molecular weights.

Apparatus for the simultaneous measurement of the X-ray absorption factor developed for a small-angle X-ray scattering beamline

2007 ◽  
Vol 40 (4) ◽  
pp. 791-795 ◽  
Author(s):  
Takeshi Morita ◽  
Yoshitada Tanaka ◽  
Kazuki Ito ◽  
Yoshihiro Takahashi ◽  
Keiko Nishikawa
Keyword(s):  
Small Angle ◽  
Performance Test ◽  
X Rays ◽  
Absorption Factor ◽  
X Ray ◽  
X Ray Scattering ◽  
X Ray Absorption ◽  
Scattering Measurement ◽  
Ray Scattering

A novel apparatus has been developed that enables the simultaneous determination of the absorption factor during measurement of small-angle X-ray scattering (SAXS) intensities of a sample. It was designed especially for the use of relatively low-energy X-rays at SAXS beamlines of synchrotron facilities. The X-ray intensity of transmittance is measured by a silicon PIN photodiode, which is implanted in a direct beamstop set in a vacuum chamber. Since the assembly transmits an attenuated direct beam to a detector during the scattering measurement, a zero-angle position can be monitored without additional operation. It was confirmed that the linearity between the signal from the photodiode and the intensity of X-rays is good and the photodiode is applicable for the desired purpose. For a performance test, the absorption factors of a supercritical fluid were measured with a wide density range.

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.

scholarly journals Small-Angle Scattering from Fractals: Differentiating between Various Types of Structures

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 65 ◽  
Author(s):  
Eugen Mircea Anitas
Keyword(s):  
Small Angle ◽  
Scattering Problem ◽  
Inverse Scattering Problem ◽  
Theoretical Models ◽  
Small Angle Scattering ◽  
X Rays ◽  
Fractal Structures ◽  
Practical Applications ◽  
Additional Information ◽  
Angle Scattering

Small-angle scattering (SAS; X-rays, neutrons, light) is being increasingly used to better understand the structure of fractal-based materials and to describe their interaction at nano- and micro-scales. To this aim, several minimalist yet specific theoretical models which exploit the fractal symmetry have been developed to extract additional information from SAS data. Although this problem can be solved exactly for many particular fractal structures, due to the intrinsic limitations of the SAS method, the inverse scattering problem, i.e., determination of the fractal structure from the intensity curve, is ill-posed. However, fractals can be divided into various classes, not necessarily disjointed, with the most common being random, deterministic, mass, surface, pore, fat and multifractals. Each class has its own imprint on the scattering intensity, and although one cannot uniquely identify the structure of a fractal based solely on SAS data, one can differentiate between various classes to which they belong. This has important practical applications in correlating their structural properties with physical ones. The article reviews SAS from several fractal models with an emphasis on describing which information can be extracted from each class, and how this can be performed experimentally. To illustrate this procedure and to validate the theoretical models, numerical simulations based on Monte Carlo methods are performed.

Structure and order in lamellar phases determined by small-angle scattering

2004 ◽  
Vol 37 (5) ◽  
pp. 703-710 ◽  
Author(s):  
Thomas Frühwirth ◽  
Gerhard Fritz ◽  
Norbert Freiberger ◽  
Otto Glatter
Keyword(s):  
Form Factor ◽  
Small Angle ◽  
Structure Factor ◽  
Scattering Length ◽  
Small Angle Scattering ◽  
Scattering Data ◽  
X Rays ◽  
Model Free ◽  
Angle Scattering

Multilamellar phases can be identified and characterized by small-angle scattering of X-rays (SAXS) or neutrons (SANS). Equidistant peaks are the typical signature and their spacing allows the fast determination of the repeat distance,i.e.the mean distance between the midplane of neighbouring bilayers. The scattering function can be described as the product of a structure factor and a form factor. The structure factor is related to the ordering of the bilayers and is responsible for the typical equidistant peaks, but it also contains information about the bilayer flexibility and the number of coherently scattering bilayers. The form factor depends on the thickness and the internal structure (scattering length density distribution) of a single bilayer. The recently developed generalized indirect Fourier transformation (GIFT) method is extended to such systems. This method allows the simultaneous determination of the structure factor and the form factor of the system, including the correction of instrumental broadening effects. A few-parameter model is used for the structure factor, while the determination of the form factor is completely model-free. The method has been tested successfully with simulated scattering data and by application to experimental data sets.

Small-angle scattering of polychromatic X-rays: effects of bandwidth, spectral shape and high harmonics

2018 ◽  
Vol 25 (2) ◽  
pp. 496-504 ◽  
Author(s):  
Sen Chen ◽  
Sheng-Nian Luo
Keyword(s):  
Small Angle ◽  
Spectral Shape ◽  
Spherical Particles ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
High Harmonics ◽  
Angle Scattering ◽  
Particle Size Determination ◽  
Photon Source

Polychromatic X-ray sources can be useful for photon-starved small-angle X-ray scattering given their high spectral fluxes. Their bandwidths, however, are 10–100 times larger than those using monochromators. To explore the feasibility, ideal scattering curves of homogeneous spherical particles for polychromatic X-rays are calculated and analyzed using the Guinier approach, maximum entropy and regularization methods. Monodisperse and polydisperse systems are explored. The influence of bandwidth and asymmetric spectra shape are exploredviaGaussian and half-Gaussian spectra. Synchrotron undulator spectra represented by two undulator sources of the Advanced Photon Source are examined as an example, as regards the influence of asymmetric harmonic shape, fundamental harmonic bandwidth and high harmonics. The effects of bandwidth, spectral shape and high harmonics on particle size determination are evaluated quantitatively.

Interpretation of small-angle X-ray scattering patterns of crystalline triglyceride nanoparticles in dispersion

2007 ◽  
Vol 40 (6) ◽  
pp. 1008-1018 ◽  
Author(s):  
T. Unruh
Keyword(s):  
Small Angle ◽  
Simulation Analysis ◽  
Aqueous Dispersion ◽  
Small Angle Scattering ◽  
X Rays ◽  
X Ray ◽  
Scattering Model ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Ray Scattering

Triglyceride nanocrystals in aqueous dispersion produced by high-pressure melt homogenization exhibit platelet-like shapes and clear but broadened Bragg reflections in the small-angle scattering regime. Because the particle thickness, the thickness of the stabilizer layer, the length scale of the crystalline structure of the nanoparticles and often the interparticle distances are of the same order of magnitude, the scattering of these structures mutually interferes. This leads to complicated small-angle scattering patterns which exhibit a lot of features, but it is not straightforward to discover the contained information on the structure of the system. In this contribution, a scattering model for such systems will be described, which is based on the kinematic scattering theory of X-rays. Using this scattering model an X-ray powder pattern simulation analysis is introduced to gain information on tripalmitin nanosuspensions which have been investigated by synchrotron small-angle X-ray scattering. It will be demonstrated that the results of this method provide a consistent description of all structural details mentioned above. In particular, information on the extension and the molecular packing density of the stabilizer layers can be achieved because these layers exhibit a comparatively large scattering contrast.

Small-Angle X-ray Scattering at the ESRF High-Brilliance Beamline

1997 ◽  
Vol 30 (5) ◽  
pp. 867-871 ◽  
Author(s):  
P. Bösecke ◽  
O. Diat
Keyword(s):  
Small Angle ◽  
Small Angle Scattering ◽  
Optical Systems ◽  
Photon Flux ◽  
X Rays ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Ray Scattering

The high-brilliance beamline (BL4/ID2) at the European Synchrotron Radiation Facility (ESRF) in Grenoble has been constructed with the emphasis on time-resolved small-angle X-ray scattering and macromolecular crystallography. It has been open to users for two years. The beamline has opened up new areas in small-angle scattering research, facilitating (a) small-angle crystallography on structures with unit cells of several hundredths of nanometres, (b) overlap with the light scattering range for the study of optical systems, (c) high photon flux for time-resolved experiments and (d) a high spatial coherence allowing submicrometre imaging with X-rays. The set-up and the detector system of the small-angle scattering station are presented. A method for obtaining absolute scattering intensities is described. The parasitic background at the station is discussed in terms of absolute scattering intensities.

On the determination of the metastable miscibility gap in ternary alloys from small-angle measurements. I. Theoretical background

1977 ◽  
Vol 10 (1) ◽  
pp. 25-27 ◽  
Author(s):  
V. Gerold
Keyword(s):  
Small Angle ◽  
Theoretical Background ◽  
Ternary Alloys ◽  
Necessary Condition ◽  
Miscibility Gap ◽  
X Rays ◽  
Angle Measurements ◽  
Angle Scattering ◽  
Line Passing

Metastable precipitation as the formation of GP zones is governed by a metastable miscibility gap. It is shown that the limits of this gap in a ternary system can be determined from combined analysis of the small-angle scattering (SAS) of X-rays and of neutrons. The necessary condition is a significantly different ratio β = (bC −bA )/(bB −bA ) of the atomic scattering amplitudes b of the components A, B and C for both the X-rays and the neutrons. This difference enables one to determine the slope of the tie-line passing through an individual alloy by comparing the integrated SAS intensities of the two types of radiation. Thereafter, the determination of the gap limits follows the same procedure as already known for binary alloys. The change of the mean atomic volume with composition influences the result, but this can be taken into account provided the same Vegard's law is valid for both the depleted matrix and the precipitate.

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