scholarly journals Self-Assembly of the Bio-Surfactant Aescin in Solution: A Small-Angle X-ray Scattering and Fluorescence Study

2019 ◽  
Vol 3 (2) ◽  
pp. 47 ◽  
Author(s):  
Carina Dargel ◽  
Ramsia Geisler ◽  
Yvonne Hannappel ◽  
Isabell Kemker ◽  
Norbert Sewald ◽  
...  
Keyword(s):  
Low Temperature ◽  
Small Angle ◽  
Self Assembly ◽  
Ph Value ◽  
Micelle Formation ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Constant Ph ◽  
Ray Scattering

This work investigates the temperature-dependent micelle formation as well as the micellar structure of the saponin aescin. The critical micelle concentration ( c m c ) of aescin is determined from the concentration-dependent autofluorescence (AF) of aescin. Values between c m c aescin , AF (10 ∘ C) = 0.38 ± 0.09 mM and c m c aescin , AF (50 ∘ C) = 0.32 ± 0.13 mM were obtained. The significance of this method is verified by tensiometry measurements. The value determined from this method is within the experimental error identical with values obtained from autofluorescence ( c m c aescin , T ( WP ) (23 ∘ C) = 0.33 ± 0.02 mM). The structure of the aescin micelles was investigated by small-angle X-ray scattering (SAXS) at 10 and 40 ∘ C. At low temperature, the aescin micelles are rod-like, whereas at high temperature the structure is ellipsoidal. The radii of gyration were determined to ≈31 Å (rods) and ≈21 Å (ellipsoid). The rod-like shape of the aescin micelles at low temperature was confirmed by transmission electron microscopy (TEM). All investigations were performed at a constant pH of 7.4, because the acidic aescin has the ability to lower the pH value in aqueous solution.

scholarly journals Alpha helical surfactant-like peptides self-assemble into pH-dependent nanostructures

Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3096-3104
Author(s):  
Valeria Castelletto ◽  
Jani Seitsonen ◽  
Janne Ruokolainen ◽  
Ian W. Hamley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Self Assembly ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Ph Dependent ◽  
Ray Scattering

A designed surfactant-like peptide is shown, using a combination of cryogenic-transmission electron microscopy and small-angle X-ray scattering, to have remarkable pH-dependent self-assembly properties.

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

Characterizing nanoparticles with a laboratory diffractometer: from small-angle to total X-ray scattering

2014 ◽  
Vol 29 (S1) ◽  
pp. S47-S53 ◽  
Author(s):  
Marco Sommariva ◽  
Milen Gateshki ◽  
Jan-André Gertenbach ◽  
Joerg Bolze ◽  
Uwe König ◽  
...  
Keyword(s):  
Small Angle ◽  
Structural Features ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Pdf Analysis ◽  
Comprehensive Picture ◽  
Ray Scattering

X-ray diffraction and scattering on a single multipurpose X-ray platform have been used to probe the structure, composition, and thermal behavior of TiO2 nanoparticles ranging in size from 1 to 10 nm. Ambient and non-ambient Bragg diffraction, small-angle X-ray scattering (SAXS), as well as total scattering and pair-distribution function (PDF) analysis are combined to obtain a comprehensive picture of the samples. At these ultrasmall particle-size dimensions, SAXS and PDF prove powerful in distinguishing the salient features of the materials, in particular the size distribution of the primary particles (SAXS) and the identification of the TiO2 polymorphs (PDF). Structural features determined by X-ray scattering techniques are corroborated by high-resolution transmission electron microscopy. The elemental make-up of the materials has been measured using X-ray fluorescence spectrometry and energy-dispersive X-ray analysis.

scholarly journals Monitoring Nanocrystal Self‐Assembly in Real Time Using In Situ Small‐Angle X‐Ray Scattering

Small ◽  
2019 ◽  
Vol 15 (20) ◽  
pp. 1900438 ◽  
Author(s):  
Irina Lokteva ◽  
Michael Koof ◽  
Michael Walther ◽  
Gerhard Grübel ◽  
Felix Lehmkühler
Keyword(s):  
Real Time ◽  
Small Angle ◽  
Self Assembly ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Nanoparticle crystal formation by solvent-assisted nanoparticle self-assembly probedin situby grazing-incidence small-angle X-ray scattering

2015 ◽  
Vol 71 (a1) ◽  
pp. s391-s391
Author(s):  
Matej Jergel ◽  
Karol Vegso ◽  
Peter Šiffalovič ◽  
Eva Majková ◽  
Adeline Buffet ◽  
...  
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Grazing Incidence ◽  
Crystal Formation ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Probing Self-Assembly of Cylindrical Morphology Block Copolymer Using in Situ and ex Situ Grazing Incidence Small-Angle X-ray Scattering: The Attractive Case of Graphoepitaxy

2014 ◽  
Vol 47 (20) ◽  
pp. 7221-7229 ◽  
Author(s):  
Mireille Maret ◽  
Raluca Tiron ◽  
Xavier Chevalier ◽  
Patrice Gergaud ◽  
Ahmed Gharbi ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Small Angle ◽  
Self Assembly ◽  
Grazing Incidence ◽  
Ex Situ ◽  
X Ray ◽  
X Ray Scattering ◽  
Attractive Case ◽  
Ray Scattering
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