scholarly journals Networks of Micellar Chains with Nanoplates

2021 ◽  
Vol 63 (2) ◽  
pp. 170-180
Author(s):  
V. S. Molchanov ◽  
A. I. Kuklin ◽  
A. S. Orekhov ◽  
N. A. Arkharova ◽  
E. S. Khudoleeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sodium Dodecyl ◽  
Bentonite Clay ◽  
Zwitterionic Surfactant ◽  
Practical Applications ◽  
Cryogenic Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
End Caps

Abstract Nanocomposite networks of surfactant micellar chains and natural bentonite clay nanoplates are studied by rheometry, small-angle neutron scattering, and cryogenic transmission electron microscopy. It is shown that, in an aqueous medium in the presence of a small part of an anionic surfactant, sodium dodecyl sulfate, the molecules of a biodegradable zwitterionic surfactant, oleyl amidopropyl dimethyl carboxybetaine, form micron-length living micellar chains which entangle and form a network possessing well-defined viscoelastic properties. It is found that addition of negatively charged clay nanoplates leads to an increase in viscosity and relaxation time by an order of magnitude. This is explained by the incorporation of the nanoplates into the network as physical multifunctional crosslinks. The incorporation occurs via the attachment of semispherical end-caps of the micelles to the surface of the particles covered with a surfactant layer, as visualized by cryogenic transmission electron microscopy. As the amount of nanoplates is increased, the rheological properties reach plateau; this is associated with the attachment of all end parts of micelles to nanoplates. The developed nanocomposite soft networks based on safe and eco-friendly components are promising for various practical applications.

scholarly journals Ultra-Low Molecular Weight Photoswitchable Hydrogelators

2020 ◽  
Author(s):  
Fayaz Larik ◽  
Lucy Fillbrook ◽  
Sandra Nurttila ◽  
Adam D Martin ◽  
Rhiannon P. Kuchel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Transmission Electron Microscopy ◽  
Low Molecular Weight ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
Hydrogen Bonding Interactions ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Rhodamine B Dye

Photoswitchable arylazopyrozoles 2 and 3 form hydrogels at a concentration of 1.2% (w/v). With a molecular weight of 258.11 g/mol, these are the lowest known molecular weight hydrogelators that respond reversibly to light. Single-crystal X-ray structures show anisotropic aggregation of 2 and 3 is driven by in-plane hydrogen bonding interactions and 𝝅 - 𝝅 stacking. Photoswitching of 2 and 3 from the E- to the Z-form by 365 nm light results in a macrocopic gel→sol transition; nearly an order of magnitude reduction in the measured elastic and loss moduli. Cryogenic transmission electron microscopy suggests that the 29±7 nm wide sheets in the E-2 gel state narrow to 13±2 nm upon photoswitching to the predominantly Z-2 solution state. In the case of 2, photoswitching is reversible through cycles of 365 nm and 520 nm excitation with little fatigue. The release of a Rhodamine B dye encapsulated in gels formed from 2 and 3 can be accelerated more than 20-fold upon photoswitching with 365 nm light, demonstrating these materials are suitable for light-controlled cargo release.

Ultra-Low Molecular Weight Photoswitchable Hydrogelators

2020 ◽  
Author(s):  
Fayaz Larik ◽  
Lucy Fillbrook ◽  
Sandra Nurttila ◽  
Adam D Martin ◽  
Rhiannon P. Kuchel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Transmission Electron Microscopy ◽  
Low Molecular Weight ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
Hydrogen Bonding Interactions ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Rhodamine B Dye

Photoswitchable arylazopyrozoles 2 and 3 form hydrogels at a concentration of 1.2% (w/v). With a molecular weight of 258.11 g/mol, these are the lowest known molecular weight hydrogelators that respond reversibly to light. Single-crystal X-ray structures show anisotropic aggregation of 2 and 3 is driven by in-plane hydrogen bonding interactions and 𝝅 - 𝝅 stacking. Photoswitching of 2 and 3 from the E- to the Z-form by 365 nm light results in a macrocopic gel→sol transition; nearly an order of magnitude reduction in the measured elastic and loss moduli. Cryogenic transmission electron microscopy suggests that the 29±7 nm wide sheets in the E-2 gel state narrow to 13±2 nm upon photoswitching to the predominantly Z-2 solution state. In the case of 2, photoswitching is reversible through cycles of 365 nm and 520 nm excitation with little fatigue. The release of a Rhodamine B dye encapsulated in gels formed from 2 and 3 can be accelerated more than 20-fold upon photoswitching with 365 nm light, demonstrating these materials are suitable for light-controlled cargo release.

Ultra-Low Molecular Weight Photoswitchable Hydrogelators

2020 ◽  
Author(s):  
Fayaz Larik ◽  
Lucy Fillbrook ◽  
Sandra Nurttila ◽  
Adam D Martin ◽  
Rhiannon P. Kuchel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Transmission Electron Microscopy ◽  
Low Molecular Weight ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
Hydrogen Bonding Interactions ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Rhodamine B Dye

Photoswitchable arylazopyrozoles 2 and 3 form hydrogels at a concentration of 1.2% (w/v). With a molecular weight of 258.11 g/mol, these are the lowest known molecular weight hydrogelators that respond reversibly to light. Single-crystal X-ray structures show anisotropic aggregation of 2 and 3 is driven by in-plane hydrogen bonding interactions and 𝝅 - 𝝅 stacking. Photoswitching of 2 and 3 from the E- to the Z-form by 365 nm light results in a macrocopic gel→sol transition; nearly an order of magnitude reduction in the measured elastic and loss moduli. Cryogenic transmission electron microscopy suggests that the 29±7 nm wide sheets in the E-2 gel state narrow to 13±2 nm upon photoswitching to the predominantly Z-2 solution state. In the case of 2, photoswitching is reversible through cycles of 365 nm and 520 nm excitation with little fatigue. The release of a Rhodamine B dye encapsulated in gels formed from 2 and 3 can be accelerated more than 20-fold upon photoswitching with 365 nm light, demonstrating these materials are suitable for light-controlled cargo release.

scholarly journals Ultra-Low Molecular Weight Photoswitchable Hydrogelators

2020 ◽  
Author(s):  
Fayaz Larik ◽  
Lucy Fillbrook ◽  
Sandra Nurttila ◽  
Adam D Martin ◽  
Rhiannon P. Kuchel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Transmission Electron Microscopy ◽  
Low Molecular Weight ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
Hydrogen Bonding Interactions ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Rhodamine B Dye

Photoswitchable arylazopyrozoles 2 and 3 form hydrogels at a concentration of 1.2% (w/v). With a molecular weight of 258.11 g/mol, these are the lowest known molecular weight hydrogelators that respond reversibly to light. Single-crystal X-ray structures show anisotropic aggregation of 2 and 3 is driven by in-plane hydrogen bonding interactions and 𝝅 - 𝝅 stacking. Photoswitching of 2 and 3 from the E- to the Z-form by 365 nm light results in a macrocopic gel→sol transition; nearly an order of magnitude reduction in the measured elastic and loss moduli. Cryogenic transmission electron microscopy suggests that the 29±7 nm wide sheets in the E-2 gel state narrow to 13±2 nm upon photoswitching to the predominantly Z-2 solution state. In the case of 2, photoswitching is reversible through cycles of 365 nm and 520 nm excitation with little fatigue. The release of a Rhodamine B dye encapsulated in gels formed from 2 and 3 can be accelerated more than 20-fold upon photoswitching with 365 nm light, demonstrating these materials are suitable for light-controlled cargo release.

scholarly journals Probing the Na metal solid electrolyte interphase via cryo-transmission electron microscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bing Han ◽  
Yucheng Zou ◽  
Zhen Zhang ◽  
Xuming Yang ◽  
Xiaobo Shi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid Electrolyte ◽  
Solid Electrolyte Interphase ◽  
Metal Electrode ◽  
Liquid Electrolyte ◽  
Battery Materials ◽  
Cryogenic Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Fluoroethylene Carbonate

AbstractCryogenic transmission electron microscopy (cryo-TEM) is a valuable tool recently proposed to investigate battery electrodes. Despite being employed for Li-based battery materials, cryo-TEM measurements for Na-based electrochemical energy storage systems are not commonly reported. In particular, elucidating the chemical and morphological behavior of the Na-metal electrode in contact with a non-aqueous liquid electrolyte solution could provide useful insights that may lead to a better understanding of metal cells during operation. Here, using cryo-TEM, we investigate the effect of fluoroethylene carbonate (FEC) additive on the solid electrolyte interphase (SEI) structure of a Na-metal electrode. Without FEC, the NaPF6-containing carbonate-based electrolyte reacts with the metal electrode to produce an unstable SEI, rich in Na2CO3 and Na3PO4, which constantly consumes the sodium reservoir of the cell during cycling. When FEC is used, the Na-metal electrode forms a multilayer SEI structure comprising an outer NaF-rich amorphous phase and an inner Na3PO4 phase. This layered structure stabilizes the SEI and prevents further reactions between the electrolyte and the Na metal.

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.

Application and Study of Reactive Polyacrylate Microgel in Pigment Paint of Printed Fabric

2011 ◽  
Vol 311-313 ◽  
pp. 1044-1048
Author(s):  
Hong Long Xing ◽  
Shui Lin Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Sodium Dodecyl ◽  
Ammonium Persulfate ◽  
Color Fastness ◽  
Adhesive Film ◽  
Transmission Electron ◽  
Divinyl Benzene

Polyacrylate microgel emulsion was prepared by emulsion polymerization using styrene, α-n-butyl acrylate and methyl methacrylate as monomer, polyoxyethylene octylphenol ether (TX-30) and sodium dodecyl sulfate(SDS) as combine emulsifier, divinyl benzene and ammonium persulfate (APS) as initiator，respectively. The prepared microgel was analyzed by a variety of measurment methods, such as Fourier transform infrared spectroscopy and transmission electron microscopy. The effect of microgel on the rheological properties of adhesives, leveling, mechanical properties and pigment printing performance was studied. The rhelogy and the color fastness of the pigment printing binder of printed fabrics were measured by rheometer and friction color fastness test instruments, respectively. At the same time, the mechanical properties of the adhesive film was measured by strength tester. The results show that the thixotropy, leveling and mechanical properties of adhesive printing binder and pringting quality of coating fabrics were improved when the microgel was added.

A method of precise misorientation determination

2003 ◽  
Vol 36 (6) ◽  
pp. 1319-1323 ◽  
Author(s):  
A. Morawiec
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Spatial Resolution ◽  
Standard Procedure ◽  
Good Spatial Resolution ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Achievable Accuracy ◽  
Better Than

A method that improves the accuracy of misorientations determined from Kikuchi patterns is described. It is based on the fact that some parameters of a misorientation calculated from two orientations are more accurate than other parameters. A procedure which eliminates inaccurate elements is devised. It requires at least two foil inclinations. The quality of the approach relies on the possibility to set large sample-to-detector distances and the availability of good spatial resolution of transmission electron microscopy. Achievable accuracy is one order of magnitude better than the accuracy of the standard procedure.

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