scholarly journals Synthesis of a Polyaniline Nanoparticle Using a Solution Plasma Process with an Ar Gas Bubble Channel

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 105 ◽  
Author(s):  
Jun-Goo Shin ◽  
Choon-Sang Park ◽  
Eun Young Jung ◽  
Bhum Jae Shin ◽  
Heung-Sik Tae
Keyword(s):  
Electron Microscopy ◽  
1H Nmr ◽  
High Speed ◽  
Low Voltage ◽  
Spherical Shape ◽  
Saed Pattern ◽  
Gas Bubble ◽  
Plasma Process ◽  
Aniline Monomer ◽  
Plasma Properties

This work researched polymerization of liquid aniline monomer by solution plasma with a gas bubble channel and investigated characteristics of solution plasma and polyaniline (PANI). The injected gas bubble channel in the proposed solution plasma process (SPP) played a significant role in producing a stable discharge in liquid aniline monomer at a low voltage and furthermore enhancing the contact surface area between liquid aniline monomer and plasma, thereby achieving polymerization on the boundary of the liquid aniline monomer and plasma. Solution plasma properties were analyzed with voltage–current, optical emission spectroscopy, and high-speed camera. Conductivity, percentage yield, and firing voltage of PANI nanoparticle dispersed solution were measured. To investigate the characteristics of synthesized PANI nanoparticles, field emission scanning electron microscopy, dynamic light scattering, transmission electron microscopy, selective area electron diffraction (SAED) pattern, Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography, 1H-nuclear magnetic resonance (1H-NMR), and X-ray photo spectroscopy (XPS) were examined. The FTIR, 1H-NMR, and XPS analysis showed the PANI characteristic peaks with evidence that some quinoid and benzene rings were broken by the solution plasma process with a gas bubble channel. The results indicate that PANI nanoparticles have a spherical shape with a size between 25 and 35 nm. The SAED pattern shows the amorphous pattern.

scholarly journals Effects of a Dielectric Barrier Discharge (DBD) on Characteristics of Polyaniline Nanoparticles Synthesized by a Solution Plasma Process with an Ar Gas Bubble Channel

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1939
Author(s):  
Jun-Goo Shin ◽  
Bhum Jae Shin ◽  
Eun Young Jung ◽  
Choon-Sang Park ◽  
Jae Young Kim ◽  
...  
Keyword(s):  
Low Temperature ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Effective Interaction ◽  
Gas Bubble ◽  
Plasma Process ◽  
Aniline Monomer ◽  
Dielectric Barrier ◽  
Polyaniline Nanoparticles ◽  
Ar Gas

The quality of polyaniline nanoparticles (PANI NPs) synthesized in plasma polymerization depends on the discharge characteristics of a solution plasma process (SPP). In this paper, the low temperature dielectric barrier discharge (DBD) is introduced to minimize the destruction of aniline molecules induced by the direct current (DC) spark discharge. By adopting the new electrode structure coupled with a gas channel, a low temperature DBD is successfully implemented in a SPP, for the first time, thus inducing an effective interaction between the Ar plasma and aniline monomer. We examine the effects of a low temperature DBD on characteristics of polyaniline nanoparticles synthesized by a SPP with an Ar gas bubble channel. As a result, both carbonization of aniline monomer and erosion of the electrode are significantly reduced, which is confirmed by analyses of the synthesized PANI NPs.

Processing of human melanoma cells for correlative TEM, LVSEM, and LM

1991 ◽  
Vol 49 ◽  
pp. 106-107
Author(s):  
Marek Malecki ◽  
J. Victor Small ◽  
James Pawley
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Fluorescent Microscopy ◽  
Blood Stream ◽  
Surface Topology ◽  
Integrin Receptors ◽  
Transmission Electron ◽  
Develop Technology ◽  
Voltage Scanning ◽  
Mechanisms Of Adhesion

The relative roles of adhesion and locomotion in malignancy have yet to be clearly established. In a tumor, subpopulations of cells may be recognized according to their capacity to invade neighbouring tissue,or to enter the blood stream and metastasize. The mechanisms of adhesion and locomotion are themselves tightly linked to the cytoskeletal apparatus and cell surface topology, including expression of integrin receptors. In our studies on melanomas with Fluorescent Microscopy (FM) and Cell Sorter(FACS), we noticed that cells in cultures derived from metastases had more numerous actin bundles, then cells from primary foci. Following this track, we attempted to develop technology allowing to compare ultrastructure of these cells using correlative Transmission Electron Microscopy(TEM) and Low Voltage Scanning Electron Microscopy(LVSEM).

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Low-voltage, high-resolution scanning electron microscopy of polymers

1987 ◽  
Vol 45 ◽  
pp. 466-467 ◽  
Author(s):  
S. J. Krause ◽  
W.W. Adams ◽  
S. Kumar ◽  
T. Reilly ◽  
T. Suziki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Chromatic Aberration ◽  
Image Resolution ◽  
Resolution Limit ◽  
Crossover Point ◽  
New Generation ◽  
Beam Damage ◽  
Scanning Electron

Scanning electron microscopy (SEM) of polymers at routine operating voltages of 15 to 25 keV can lead to beam damage and sample image distortion due to charging. Imaging polymer samples with low accelerating voltages (0.1 to 2.0 keV), at or near the “crossover point”, can reduce beam damage, eliminate charging, and improve contrast of surface detail. However, at low voltage, beam brightness is reduced and image resolution is degraded due to chromatic aberration. A new generation of instruments has improved brightness at low voltages, but a typical SEM with a tungsten hairpin filament will have a resolution limit of about 100nm at 1keV. Recently, a new field emission gun (FEG) SEM, the Hitachi S900, was introduced with a reported resolution of 0.8nm at 30keV and 5nm at 1keV. In this research we are reporting the results of imaging coated and uncoated polymer samples at accelerating voltages between 1keV and 30keV in a tungsten hairpin SEM and in the Hitachi S900 FEG SEM.

Image quality vs data obtainment in biological electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 42-43
Author(s):  
J. E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Image Quality ◽  
High Speed ◽  
Early Period ◽  
Early Years ◽  
Fluorescent Screen ◽  
Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

Actin filaments in two spermatozoa of crustacea decapoda

1990 ◽  
Vol 48 (3) ◽  
pp. 70-71
Author(s):  
E. Dupré ◽  
G. Schatten
Keyword(s):  
Electron Microscopy ◽  
Actin Filaments ◽  
Low Voltage ◽  
Active Role ◽  
Main Body ◽  
Robinson Crusoe ◽  
Decapod Crustaceans ◽  
Actual Participation ◽  
Voltage Scanning ◽  
Scanning Electron

Sperm of decapod crustaceans are formed by a round or cup-shaped body, a complex acrosome and one a few appendages emerging from the main body. Although this sperm does not have motility, it has some components of the cytoskeleton like microtubules, which are found inside the appendages. Actin filaments have been found in the spike of penaeidae sperms. The actual participation of the crustacean decapod sperm cytoskeleton during fertilization is not well understood. Actin is supposed to play an active role in drawing the penaeidae shrimp sperm closer to the egg after bending of the spike. The present study was aimed at the localization of actin filaments in sperm of the Robinson Crusoe island lobster, Jasus frontalis and in the crayfish Orconectes propincus, by fluorescent probes and low voltage scanning electron microscopy.

Thrombus formation on artificial surfaces: Correlative microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 840-841
Author(s):  
Quintin J. Lai ◽  
Stuart L. Cooper ◽  
Ralph M. Albrecht
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Thrombus Formation ◽  
Blood Platelets ◽  
Polymer Surfaces ◽  
Flow Conditions ◽  
Transmission Electron ◽  
Adhesion Of Platelets ◽  
Microscopic Techniques

Thrombus formation and embolization are significant problems for blood-contacting biomedical devices. Two major components of thrombi are blood platelets and the plasma protein, fibrinogen. Previous studies have examined interactions of platelets with polymer surfaces, fibrinogen with platelets, and platelets in suspension with spreading platelets attached to surfaces. Correlative microscopic techniques permit light microscopic observations of labeled living platelets, under static or flow conditions, followed by the observation of identical platelets by electron microscopy. Videoenhanced, differential interference contrast (DIC) light microscopy permits high-resolution, real-time imaging of live platelets and their interactions with surfaces. Interference reflection microscopy (IRM) provides information on the focal adhesion of platelets on surfaces. High voltage, transmission electron microscopy (HVEM) allows observation of platelet cytoskeletal structure of whole mount preparations. Low-voltage, high resolution, scanning electron microscopy allows observation of fine surface detail of platelets. Colloidal gold-labeled fibrinogen, used to identify the Gp Ilb/IIIa membrane receptor for fibrinogen, can be detected in all the above microscopies.

The bright future of digital imaging in scanning electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 768-769
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Imaging ◽  
High Speed ◽  
High Performance ◽  
Mass Storage ◽  
Analog To Digital ◽  
Central Processing ◽  
Digital Imaging Technology ◽  
Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.

Novel Approaches to Low-Voltage Scanning Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 366-367
Author(s):  
Arthur V. Jones
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Electron Optics ◽  
Current Interest ◽  
New Concepts ◽  
Opportune Time ◽  
Novel Approaches ◽  
Voltage Scanning ◽  
Scanning Electron

In comparison with the developers of other forms of instrumentation, scanning electron microscope manufacturers are among the most conservative of people. New concepts usually must wait many years before being exploited commercially. The field emission gun, developed by Albert Crewe and his coworkers in 1968 is only now becoming widely available in commercial instruments, while the innovative lens designs of Mulvey are still waiting to be commercially exploited. The associated electronics is still in general based on operating procedures which have changed little since the original microscopes of Oatley and his co-workers.The current interest in low-voltage scanning electron microscopy will, if sub-nanometer resolution is to be obtained in a useable instrument, lead to fundamental changes in the design of the electron optics. Perhaps this is an opportune time to consider other fundamental changes in scanning electron microscopy instrumentation.

Spin-polarized Scanning Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 768-769
Author(s):  
Kazuyuki Koike ◽  
Hideo Matsuyama
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Speed ◽  
Magnetic Thin Films ◽  
Electron Spin Polarization ◽  
Acquisition Time ◽  
Magnetization Direction ◽  
Spin Polarized ◽  
Conventional Methods ◽  
Scanning Electron

Spin-polarized scanning electron microscopy (spin SEM), where the secondary electron spin polarization is used as the image signal, is a novel technique for magnetic domain observation. Since its first development by Koike and Hayakawa in 1984, several laboratories have extensively studied this technique and have greatly improved its capability for data extraction and its range of applications. This paper reviews the progress over the last few years.Almost all the high expectations initially held for spin SEM have been realized. A spatial resolution of several hundreds angstroms has been attained, which is nearly one order of magnitude higher than that of conventional methods for thick samples. Quantitative analysis of magnetization direction has been performed more easily than with conventional methods. Domain observation of the surface of three-dimensional samples has been confirmed to be possible. One of the drawbacks, a long image acquisition time, has been eased by combining highspeed image-signal processing with high speed scanning, although at the cost of image quality. By using spin SEM, the magnetic structure of a 180 degrees surface Neel wall, magnetic thin films, multilayered films, magnetic discs, etc., have been investigated.

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