Micellar growth and network formation in acidic solutions of a sulfobetaine zwitterionic surfactant triggered by an inorganic salt

Soft Matter ◽  
2020 ◽  
Vol 16 (18) ◽  
pp. 4494-4501 ◽  
Author(s):  
Salar Afra ◽  
Hamidreza Samouei ◽  
Phuc Truong ◽  
Hisham Nasr-El-Din
Keyword(s):  
Network Formation ◽  
Inorganic Salt ◽  
Iron Chloride ◽  
Zwitterionic Surfactant ◽  
X Ray ◽  
Acidic Solutions ◽  
X Ray Scattering ◽  
Micellar Growth ◽  
Dimethyl Ammonium ◽  
Acidic Conditions

Micellization (formation of wormlike structures) of 3-(N-erucamidopropyl-N,N-dimethyl ammonium)propane sulfonate (EDAS) in the presence of an inorganic salt, iron chloride (FeCl3), in acidic conditions is studied using static and dynamic rheological measurements and small-angle X-ray scattering (SAXS).

scholarly journals Kinetics of Network Formation and Heterogeneous Dynamics of an Egg White Gel Revealed by Coherent X-Ray Scattering

2021 ◽  
Vol 126 (9) ◽  
Author(s):  
Nafisa Begam ◽  
Anastasia Ragulskaya ◽  
Anita Girelli ◽  
Hendrik Rahmann ◽  
Sivasurender Chandran ◽  
...  
Keyword(s):  
Network Formation ◽  
Egg White ◽  
X Ray ◽  
X Ray Scattering ◽  
Heterogeneous Dynamics ◽  
Kinetics Of ◽  
Ray Scattering

scholarly journals Structure and Rheology of Polyelectrolyte Complexes in the Presence of a Hydrogen-Bonded Co-Solvent

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1053 ◽  
Author(s):  
Mor Boas ◽  
Gleb Vasilyev ◽  
Rita Vilensky ◽  
Yachin Cohen ◽  
Eyal Zussman
Keyword(s):  
Aqueous Solution ◽  
Network Formation ◽  
Mixed Solvent ◽  
Relative Viscosity ◽  
Degree Of Ionization ◽  
Polyelectrolyte Complexes ◽  
X Ray ◽  
Macromolecular Conformation ◽  
X Ray Scattering ◽  
Transmission Electron

Intermolecular interactions as well as macromolecular conformation affect the rheological and microstructural properties of polyelectrolyte complexes (PECs) solutions. The properties of semi-dilute solutions of weakly charged PECs can be controlled by the degree of ionization and solvent composition. In this work, we examined the effect of ethanol as a co-solvent on PECs composed of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) at low pH. The aqueous PECs solution was turbid, indicating formation of large aggregates, whereas PECs solution in water/ethanol (60:40 w/w) was transparent, implying no aggregation, and demonstrated higher relative viscosity than the aqueous solution, implying pronounced network formation. Imaging PECs solution by transmission electron microscopy (TEM) demonstrated aggregation, whereas the solution prepared with the mixed solvent revealed almost no phase contrast. Small-angle X-ray scattering (SAXS) of PECs in the aqueous solution indicated the presence of aggregates, while PECs in mixed solvent demonstrated a swelled macromolecular conformation with diminished aggregation. PECs with no ionic interactions in the mixed solvent assumes a homogenous network structure, which enables PECs solution processing by electrospinning.

Polysiloxane network formation observed by time-resolved small-angle X-ray scattering

1993 ◽  
Vol 1 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Toshiya Ando ◽  
Shigenobu Yamanaka ◽  
Shinzo Kohjiya ◽  
Kanji Kajiwara
Keyword(s):  
Small Angle ◽  
Network Formation ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Hydrogel networks by aliphatic dithiol Michael addition to glycidylmethacrylated gelatin

MRS Advances ◽  
2021 ◽  
Author(s):  
Axel T. Neffe ◽  
Candy Löwenberg ◽  
Andreas Lendlein
Keyword(s):  
Network Formation ◽  
Molar Ratio ◽  
Elongation At Break ◽  
X Ray ◽  
H Nmr ◽  
X Ray Scattering ◽  
Ft Ir ◽  
Triple Helices ◽  
Hydrogel Swelling ◽  
Ft Ir Spectroscopy

AbstractFunctionalization of gelatin with glycidylmethacrylate (GMA-gelatin) enables network formation employing the double bond, so that the reaction is orthogonal to the inherent functional groups in the biomacromolecule. Here, network formation by crosslinking of GMA-gelatin with hexane 1,6-dithiol or nonane 1,9-dithiol to tailor properties and enable a shape-memory effect is shown by 1H NMR and FT-IR spectroscopy. Hydrogel swelling (460–1900 vol%) and mechanical properties (Young’s modulus E = 59–512 kPa, elongation at break εb = 44–127%) depended on the molecular composition of the networks and temperature. Increased crosslinker length, thiol:methacrylate molar ratio, and precursor concentrations led to denser networks. Change of properties with temperature suggested adoption of triple helices by gelatin chains, forming physical netpoints at lower temperatures (< 20 °C). However, the limited freedom of the gelatin chains to move allowed only a minimal extent of triple helices formation, as it became apparent from the related signal in wide-angle X-ray scattering and the thermal transition associated to triple helices in some networks by DSC. The presented strategy is likely transferable to other biomacromolecules, and the results suggest that too short crosslinkers may result in a significant amount of grafting rather than network formation. Graphic abstract

scholarly journals Examination of well ordered nanonetwork materials by real- and reciprocal-space imaging

IUCrJ ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 259-266 ◽  
Author(s):  
Po-Ting Chiu ◽  
Yu-Cheng Chien ◽  
Prokopios Georgopanos ◽  
Ya-Sen Sun ◽  
Apostolos Avgeropoulos ◽  
...  
Keyword(s):  
Form Factor ◽  
Electroless Plating ◽  
Network Formation ◽  
Real Space ◽  
Reciprocal Space ◽  
Scattering Data ◽  
Structured Materials ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The development of well ordered nanonetwork materials (in particular gyroid-structured materials) has been investigated using a block-copolymer template for templated electroless plating as an example system for the examination of network formation using X-ray scattering. By taking advantage of the nucleation and growth mechanism of templated electroless plating, gyroid-structured Au was successfully fabricated through the development of Au nanoparticles, then tripods and branched tripods, and finally an ordered network. Each stage in the development of the network phase could then be examined by combining real-space transmission electron microscopy observations with reciprocal-space small-angle X-ray scattering results. The fingerprint scattering profile of the building block for the network (i.e. the tripod of the gyroid) could be well fitted with the form factor of an effective sphere, and the diffraction results from the ordered network could thus be reasonably addressed. As a result, the examination of well ordered network materials can be simplified as the scattering from the form factor of a sphere convoluted with the nodes of its structure factor, providing a facile method of identifying the network phases from X-ray scattering data.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Time-Resolved Cryo-Electron Microscopy of Oscillating Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 502-503
Author(s):  
Eva-Maria Mandelkow ◽  
Ron Milligan
Keyword(s):  
Electron Microscopy ◽  
Dynamic Instability ◽  
Entire Solution ◽  
Reaction Scheme ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
A Chain ◽  
Ray Scattering

Microtubules form part of the cytoskeleton of eukaryotic cells. They are hollow libers of about 25 nm diameter made up of 13 protofilaments, each of which consists of a chain of heterodimers of α-and β-tubulin. Microtubules can be assembled in vitro at 37°C in the presence of GTP which is hydrolyzed during the reaction, and they are disassembled at 4°C. In contrast to most other polymers microtubules show the behavior of “dynamic instability”, i.e. they can switch between phases of growth and phases of shrinkage, even at an overall steady state [1]. In certain conditions an entire solution can be synchronized, leading to autonomous oscillations in the degree of assembly which can be observed by X-ray scattering (Fig. 1), light scattering, or electron microscopy [2-5]. In addition such solutions are capable of generating spontaneous spatial patterns [6].In an earlier study we have analyzed the structure of microtubules and their cold-induced disassembly by cryo-EM [7]. One result was that disassembly takes place by loss of protofilament fragments (tubulin oligomers) which fray apart at the microtubule ends. We also looked at microtubule oscillations by time-resolved X-ray scattering and proposed a reaction scheme [4] which involves a cyclic interconversion of tubulin, microtubules, and oligomers (Fig. 2). The present study was undertaken to answer two questions: (a) What is the nature of the oscillations as seen by time-resolved cryo-EM? (b) Do microtubules disassemble by fraying protofilament fragments during oscillations at 37°C?

X-ray scattering by 1D molecular Guinier-Preston zones in ordered smectic phases

1992 ◽  
Vol 2 (6) ◽  
pp. 899-913 ◽  
Author(s):  
Patrick Davidson ◽  
Elisabeth Dubois-Violette ◽  
Anne-Marie Levelut ◽  
Brigitte Pansu
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Smectic Phases ◽  
Ray Scattering

An X-ray Scattering Study of Laterally Modulated Structures: Investigation of Coherence and Resolution Effects with a Grating

1996 ◽  
Vol 6 (8) ◽  
pp. 1085-1094 ◽  
Author(s):  
A. Gibaud ◽  
J. Wang ◽  
M. Tolan ◽  
G. Vignaud ◽  
S. K. Sinha
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Modulated Structures ◽  
Scattering Study ◽  
Ray Scattering

Pixel detectors: New detectors for X-ray scattering

2002 ◽  
Vol 12 (6) ◽  
pp. 385-390 ◽  
Author(s):  
J.-F. Bérar ◽  
L. Blanquart ◽  
N. Boudet ◽  
P. Breugnon ◽  
B. Caillot ◽  
...  
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Pixel Detectors ◽  
Ray Scattering
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