Study on Microstructures of Polycarboxylate-Type Superplasticizers with Different Side Chains

2012 ◽  
Vol 531-532 ◽  
pp. 640-644
Author(s):  
Xiong Yi Peng ◽  
Cong Hua Yi ◽  
Qian Qian Tang ◽  
Xue Qing Qiu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrogen Bonding ◽  
Self Assembly ◽  
Degree Of Polymerization ◽  
The Self ◽  
Side Chains ◽  
Transmission Electron ◽  
Assembly Technique ◽  
Solution Increase

Polycarboxylate-type superplasticizers with different side chains and approximative degree of polymerization are synthesized. The microstructures of Polycarboxylate-type superplasticizers in water are studied by fluorescent probe technique, dynamic light scattering (DLS), transmission electron microscopy (TEM) and the self-assembly technique. The results indicate that the formation of hydrophobic microenvironment in PC solution is confirmed. The higher the ratio of long side chains of PC, the stronger the hydrophobic microenvironment formed in PC solution. The Z-Average diameters of aggregation formed in PC solution increase with the increasing of long side chains content. In addition, the size and shape of aggregation is not of uniform distribution, and the reason for this is that association interaction of hydrogen bonding occurs among PC molecules or in the interior of single PC molecule.

Fabrication of Nanosheets and Micro-Spheres from the Self-Assembly and Polymerization of N-Octadecyltrichlorosilane

2011 ◽  
Vol 311-313 ◽  
pp. 485-488 ◽  
Author(s):  
Shuai Zhang ◽  
Qing Ping Ke ◽  
Lei Zhang ◽  
Tian Di Tang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Self Assembly ◽  
Micelle Formation ◽  
The Self ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrolysis Process ◽  
Scanning Electron

Formation of layered nanosheets and micro-spheres from a simple self-assembly and polycondensation of n-octadecylsilane (PODS) in water and toluene is demonstrated, respectively. The structure of the micro-spheres was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). According to the TEM images, it was firstly confirmed that the micro-spheres consist of stacks of bilayered polymerized n-octadecylsilane with head-to-head arrangements. The co-effects of water and solvent were proposed to control the octadecyltrichlsilane hydrolysis process and eventually the morphology of the micro-spheres. A micelle formation mechanism for the formation of the PODS micro-spheres under the co-effects of water and solvent were firstly proposed.

Synthesis and Microstructure Study of Polycarboxylated Superplasticizer with Different Carboxylic Group Content

2013 ◽  
Vol 328 ◽  
pp. 802-807 ◽  
Author(s):  
Xiong Yi Peng ◽  
Ming Gui Xia
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrogen Bonding ◽  
Light Scattering ◽  
Fluorescence Probe ◽  
Degree Of Polymerization ◽  
Carboxylic Group ◽  
Group Content ◽  
Transmission Electron ◽  
Regular Sphere

Polycarboxylate-type superplasticizers (PCs) with different carboxylic group content and the same degree of polymerization are synthesized. Their microstructures are studied by fluorescent probe technique, dynamic light scattering (DLS) and transmission electron microscopy (TEM). The method of fluorescence probe confirms that there is the formation of hydrophobic microenvironment in PC solution, and PC with low carboxylic group content produces a stronger hydrophobic microenvironment than PC with high carboxylic group content. The DLS and TEM studies find that Z-Average diameters of aggregation produced by PC with low carboxylic group content is larger than that of aggregation produced by PC with high carboxylic group content. In addition, the shape of aggregation is not regular sphere. The reason for this is that association interaction of hydrogen bonding may occur among PC molecules or in the interior of single PC molecule.

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.

Studies of Compositional Variations in Germanium Quantum Dots Grown on Silicon

2000 ◽  
Vol 638 ◽  
Author(s):  
Alan D.F. Dunbar ◽  
Matthew P. Halsall ◽  
Uschi Bangert ◽  
Alan Harvey ◽  
Philip Dawson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
The Self ◽  
Asymmetric Distribution ◽  
Scanning Transmission Electron ◽  
Self Organized ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Uk

AbstractWe report optical and scanning transmission electron microscopy studies of germanium dots grown on silicon. In an attempt to control the self-organized growth process and promote dot size uniformity the dot layers were grown on a 4.5nm Si0.6Ge0.4 alloy template layer. Photoluminescence results indicate the formation of carrier confining Ge rich islands, whilst Raman scattering results indicate the presence of an alloy throughout the structures formed. The samples were studied in the UK high resolution scanning transmission electron microscopy facility at Liverpool, UK. Energy dispersive analysis of individual line scans through the sample show that the structures are composed of an alloy throughout with an asymmetric distribution of Germanium in the dots and in the wetting layer close to the dots. We discuss the results in the light of the proposed growth mode for these dots and conclude that attempts to manipulate the composition of these dots during growth may be problematic due to the self-organized nature of their formation.

scholarly journals Zig-zag Self-assembly of Magnetic Octahedral Fe3O4 Nanocrystals using in situ Liquid Transmission Electron Microscopy

2016 ◽  
Vol 22 (S5) ◽  
pp. 36-37
Author(s):  
Arnaud Demortiere ◽  
Charudatta Phatak ◽  
Andras Kovacs ◽  
Jan Caron ◽  
Nikita Repnin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Self Assembly ◽  
Transmission Electron

scholarly journals Controlled self-assembly of stomatosomes by use of single-component fluorinated dendritic amphiphiles

Soft Matter ◽  
2018 ◽  
Vol 14 (25) ◽  
pp. 5256-5269 ◽  
Author(s):  
H. v. Berlepsch ◽  
B. N. S. Thota ◽  
M. Wyszogrodzka ◽  
S. de Carlo ◽  
R. Haag ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Self Assembly ◽  
Single Component ◽  
Alkyl Chains ◽  
Flexible Spacer ◽  
Head Groups ◽  
Transmission Electron

A series of novel non-ionic amphiphiles with dendritic oligoglycerol head groups and lipophilic/fluorophilic tail segments, comprising single or double tail alkyl chains, C8F17-perfluoro rod segments as well as flexible spacer groups were designed and their supramolecular behavior characterised by cryo-transmission electron microscopy and tomography.

Cryogenic Transmission Electron Microscopy: Aqueous Suspensions of Nanoscale Objects

2013 ◽  
Vol 19 (6) ◽  
pp. 1542-1553 ◽  
Author(s):  
Nathan D. Burrows ◽  
R. Lee Penn
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Self Assembly ◽  
Aqueous Samples ◽  
Liquid Media ◽  
Cryogenic Transmission Electron Microscopy ◽  
Transmission Electron ◽  
The Many

AbstractDirect imaging of nanoscale objects suspended in liquid media can be accomplished using cryogenic transmission electron microscopy (cryo-TEM). Cryo-TEM has been used with particular success in microbiology and other biological fields. Samples are prepared by plunging a thin film of sample into an appropriate cryogen, which essentially produces a snapshot of the suspended objects in their liquid medium. With successful sample preparation, cryo-TEM images can facilitate elucidation of aggregation and self-assembly, as well as provide detailed information about cells and viruses. This work provides an explanation of sample preparation, detailed examples of the many artifacts found in cryo-TEM of aqueous samples, and other key considerations for successful cryo-TEM imaging.

The Self-Organisation of Tetrahedrally Close-Packed Structures in Magnetic Nanocrystalline Tb-Fe and Co-Pd Films

2006 ◽  
Vol 115 ◽  
pp. 267-274
Author(s):  
L.I. Kveglis ◽  
A.V. Kuzovnikov ◽  
I.V. Timofeev
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Model ◽  
Perpendicular Magnetic Anisotropy ◽  
Dissipative Structures ◽  
The Self ◽  
Self Organization ◽  
Nanocrystalline State ◽  
Transmission Electron

The self-organization of an atomic structure in Tb30Fe70 and Co50Pd50 films possessing of high values of the perpendicular magnetic anisotropy (PMA) constant (K⊥ ~ 106 erg/cm3) is investigated by transmission electron microscopy. The crystallization of the films is realized in an explosive way with formation of different dissipative structures from the initial nanocrystalline state. In present work the structural model of a thin film in mezzo-scale and the correlation of a structure with magnetic properties are discussed.

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