New Insights into Ionic Aggregate Morphology in Zn-Neutralized Sulfonated Polystyrene Ionomers by Transmission Electron Tomography

2011 ◽  
Vol 44 (20) ◽  
pp. 8093-8099 ◽  
Author(s):  
Florent Dalmas ◽  
Eric Leroy
Keyword(s):  
Electron Tomography ◽  
Sulfonated Polystyrene ◽  
Transmission Electron ◽  
Aggregate Morphology

Imaging Ionic Aggregates in Zn-Neutralized Sulfonated Polystyrene Ionomers: Shape and Spatial Heterogeneity

2000 ◽  
Vol 6 (S2) ◽  
pp. 1112-1113
Author(s):  
Brian P. Kirkmeyer ◽  
Robert A. Weiss ◽  
Karen I. Winey
Keyword(s):  
Quantitative Information ◽  
Sulfonated Polystyrene ◽  
Anionic Polymer ◽  
Saxs Data ◽  
Polymer Backbone ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Aggregate Morphology ◽  
Common Technique ◽  
Neutralizing Agent

Ionomers are ionically-associating copolymers whose distinctive rheological and mechanical properties arise from the formation of ionic aggregates. The ionic aggregates form when dipoles of minority anionic polymer backbone segments and cationic neutralizing species locally associate and dissociate among each other. Specific ionomer properties depend upon the base copolymer, the minority constituent and the neutralizing agent. One system that has been studied extensively is sulfonated polystyrene ionomer neutralized with Zn (Zn-SPS). The most common technique to date for studying ionomer morphology is small-angle x-ray scattering (SAXS). This technique has provided quantitative information about the aggregate morphology by imposing morphology models that have not been independently confirmed.In the present study, we demonstrate the capability to directly image the ionic aggregates of Zn-SPS ionomers using scanning transmission electron microscopy (STEM). This method will allow us to confirm or deny the competing morphological models applied to SAXS data. We have applied similar methods to polyethylene-based ionomers.

Automated electron tomography: from data collection to image processing

1995 ◽  
Vol 53 ◽  
pp. 26-27
Author(s):  
Weiping Liu ◽  
Jennifer Fung ◽  
W.J. de Ruijter ◽  
Hans Chen ◽  
John W. Sedat ◽  
...  
Keyword(s):  
Image Processing ◽  
Data Collection ◽  
Structural Information ◽  
Imaging Technique ◽  
Electron Tomography ◽  
Ccd Camera ◽  
Automated Data Collection ◽  
Full Control ◽  
Transmission Electron ◽  
Amorphous Structures

Electron tomography is a technique where many projections of an object are collected from the transmission electron microscope (TEM), and are then used to reconstruct the object in its entirety, allowing internal structure to be viewed. As vital as is the 3-D structural information and with no other 3-D imaging technique to compete in its resolution range, electron tomography of amorphous structures has been exercised only sporadically over the last ten years. Its general lack of popularity can be attributed to the tediousness of the entire process starting from the data collection, image processing for reconstruction, and extending to the 3-D image analysis. We have been investing effort to automate all aspects of electron tomography. Our systems of data collection and tomographic image processing will be briefly described.To date, we have developed a second generation automated data collection system based on an SGI workstation (Fig. 1) (The previous version used a micro VAX). The computer takes full control of the microscope operations with its graphical menu driven environment. This is made possible by the direct digital recording of images using the CCD camera.

Cryo-scanning transmission electron tomography of vitrified cells

2014 ◽  
Vol 11 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Sharon Grayer Wolf ◽  
Lothar Houben ◽  
Michael Elbaum
Keyword(s):  
Electron Tomography ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

scholarly journals Exploring the Capability of HAADF-STEM Techniques to Characterize Graphene Distribution in Nanocomposites by Simulations

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
N. Baladés ◽  
D. L. Sales ◽  
M. Herrera ◽  
A. M. Raya ◽  
J. C. Hernández-Garrido ◽  
...  
Keyword(s):  
Electron Tomography ◽  
Carbon Matrix ◽  
Reconstruction Algorithm ◽  
Dark Field ◽  
Graphene Layers ◽  
Transmission Electron ◽  
Dispersion Degree ◽  
Scanning Transmission ◽  
The Matrix ◽  
Annular Dark Field

This paper explores the capability of scanning transmission electron microscopy (STEM) techniques in determining the dispersion degree of graphene layers within the carbon matrix by using simulated high-angle annular dark-field (HAADF) images. Results ensure that unmarked graphene layers are only detectable if their orientation is parallel to the microscope beam. Additionally, gold-marked graphene layers allow evaluating the dispersion degree in structural composites. Moreover, electron tomography has been demonstrated to provide truthfully 3D distribution of the graphene sheets inside the matrix when an appropriate reconstruction algorithm and 2D projections including channelling effect are used.

scholarly journals Automated cryo-lamella preparation for high-throughput in-situ structural biology

2019 ◽  
Author(s):  
Genevieve Buckley ◽  
Gediminas Gervinskas ◽  
Cyntia Taveneau ◽  
Hari Venugopal ◽  
James C. Whisstock ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Structural Biology ◽  
Focused Ion Beam ◽  
Electron Tomography ◽  
Ion Beam ◽  
Automated Method ◽  
Cellular Environment ◽  
Transmission Electron

AbstractCryo-transmission electron tomography (cryo-ET) in association with cryo-focused ion beam (cryo-FIB) milling enables structural biology studies to be performed directly within the cellular environment. Cryo-preserved cells are milled and a lamella with a thickness of 200-300 nm provides an electron transparent window suitable for cryo-ET imaging. Cryo-FIB milling is an effective method, but it is a tedious and time-consuming process, which typically results in ~10 lamellae per day. Here, we introduce an automated method to reproducibly prepare cryo-lamellae on a grid and reduce the amount of human supervision. We tested the routine on cryo-preserved Saccharomyces cerevisiae and demonstrate that this method allows an increased throughput, achieving a rate of 5 lamellae/hour without the need to supervise the FIB milling. We demonstrate that the quality of the lamellae is consistent throughout the preparation and their compatibility with cryo-ET analyses.

Three-Dimensional Dispersion of Nano-Fillers in Soft Composite as Revealed by Transmission Electron Microscopy/Electron Tomography (3D-TEM)

2006 ◽  
Vol 514-516 ◽  
pp. 353-358 ◽  
Author(s):  
Shinzo Kohjiya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Natural Rubber ◽  
Structural Information ◽  
Electron Tomography ◽  
Nano Composites ◽  
Nano Structure ◽  
Transmission Electron ◽  
Particulate Silica

. Generally rubber products are a typical soft material, and a composite of a nano-filler (typically, carbon black or particulate silica) and a rubber (natural rubber and various synthetics are used). The properties of these soft nano-composites have been well known to depend on the dispersion of the nano-filler in the rubbery matrix. The most powerful tool for the elucidation of it has been transmission electron microscopy (TEM). The microscopic techniques are based on the projection of 3-dimensional (3D) body on a plane (x, y plane), thus the structural information along the thickness (z axis) direction of the sample is difficult to obtain. This paper describes our recent results on the dispersion of carbon black (CB) and particulate silica in natural rubber (NR) matrix observed by TEM combined with electron tomography (3D-TEM) technique, which enabled us to obtain images of 3D nano-structure of the sample. Thus, 3D images of CB and silica in NR matrix are visualized and analyzed in this communication. These results are precious ones for the design of soft nano-composites, and the technique will become an indispensable one in nanotechnology.

scholarly journals Recent Advances in Transmission Electron Microscopy for Materials Science at the EMAT Lab of the University of Antwerp

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1304 ◽  
Author(s):  
Giulio Guzzinati ◽  
Thomas Altantzis ◽  
Maria Batuk ◽  
Annick De Backer ◽  
Gunnar Lumbeeck ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Materials Science ◽  
Electron Tomography ◽  
High Resolution Imaging ◽  
Rapid Progress ◽  
Transmission Electron ◽  
The World ◽  
Resolution Imaging ◽  
The University

The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium’s foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab’s recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science.

scholarly journals Primary ciliary dyskinesia with normal ultrastructure: three-dimensional tomography detects absence of DNAH11

2018 ◽  
Vol 51 (2) ◽  
pp. 1701809 ◽  
Author(s):  
Amelia Shoemark ◽  
Thomas Burgoyne ◽  
Robert Kwan ◽  
Mellisa Dixon ◽  
Mitali P. Patel ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Structural Abnormality ◽  
Healthy Controls ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Causal Variants ◽  
Diagnostic Samples ◽  
Ciliary Dyskinesia

In primary ciliary dyskinesia (PCD), motile ciliary dysfunction arises from ciliary defects usually confirmed by transmission electron microscopy (TEM). In 30% of patients, such as those with DNAH11 mutations, apparently normal ultrastructure makes diagnosis difficult. Genetic analysis supports diagnosis, but may not identify definitive causal variants. Electron tomography, an extension of TEM, produces three-dimensional ultrastructural ciliary models with superior resolution to TEM. Our hypothesis is that tomography using existing patient samples will enable visualisation of DNAH11-associated ultrastructural defects. Dual axis tomograms from araldite-embedded nasal cilia were collected in 13 PCD patients with normal ultrastructure (DNAH11 n=7, HYDIN n=2, CCDC65 n=3 and DRC1 n=1) and six healthy controls, then analysed using IMOD and Chimera software.DNAH11 protein is localised to the proximal ciliary region. Within this region, electron tomography indicated a deficiency of >25% of proximal outer dynein arm volume in all patients with DNAH11 mutations (n=7) compared to other patients with PCD and normal ultrastructure (n=6) and healthy controls (n=6). DNAH11 mutations cause a shared abnormality in ciliary ultrastructure previously undetectable by TEM. Advantageously, electron tomography can be used on existing diagnostic samples and establishes a structural abnormality where ultrastructural studies were previously normal.

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