Chemical fingerprinting of polyvinyl acetate and polycarbonate using electron energy-loss spectroscopy

2020 ◽  
Vol 11 (34) ◽  
pp. 5484-5492
Author(s):  
Ruchi Pal ◽  
Laure Bourgeois ◽  
Matthew Weyland ◽  
Arun K. Sikder ◽  
Kei Saito ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Chemical Structure ◽  
Polyvinyl Acetate ◽  
Polymeric Materials ◽  
High Sensitivity ◽  
Chemical Fingerprinting ◽  
Electron Energy Loss

This work demonstrates that the high sensitivity of EELS can be used to identify the changes in the chemical structure of polymeric materials.

scholarly journals Chemical identification through two-dimensional electron energy-loss spectroscopy

2020 ◽  
Vol 6 (28) ◽  
pp. eabb4713
Author(s):  
Renwen Yu ◽  
F. Javier García de Abajo
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Electronic Device ◽  
Theoretical Calculations ◽  
Chemical Species ◽  
High Sensitivity ◽  
Two Dimensional ◽  
Excitation Spectra ◽  
Electron Energy Loss

We explore a disruptive approach to nanoscale sensing by performing electron energy loss spectroscopy through the use of low-energy ballistic electrons that propagate on a two-dimensional semiconductor. In analogy to free-space electron microscopy, we show that the presence of analyte molecules in the vicinity of the semiconductor produces substantial energy losses in the electrons, which can be resolved by energy-selective electron injection and detection through actively controlled potential gates. The infrared excitation spectra of the molecules are thereby gathered in this electronic device, enabling the identification of chemical species with high sensitivity. Our realistic theoretical calculations demonstrate the superiority of this technique for molecular sensing, capable of performing spectral identification at the zeptomol level within a microscopic all-electrical device.

Subcellular Localization of Fluorinated Serotonin in Human Platelets by Electron Energy-Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 238-239
Author(s):  
J.L. Costa ◽  
D.C. Joy ◽  
D.M. Maher ◽  
K.L. Kirk ◽  
S.W. Hui
Keyword(s):  
Subcellular Localization ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
High Sensitivity ◽  
Spot Size ◽  
Human Platelets ◽  
Parent Molecule ◽  
Low Sensitivity ◽  
Electron Energy Loss

Fluorinated organic molecules have considerable potential as tracers in bio logical systems, since a number of fluorinated analogs demonstrate biological activity similar to that of the parent molecule1. To date, however, the subcellular localization of fluorine has been hampered by the relatively low sensitivity of conventional X-ray microanalysis systems to fluorine. Electron energy-loss spectroscopy, in contrast, is a very efficient method for detecting light elements. We have capitalized on the high sensitivity of this technique to fluorine to identify and localize fluorinated serotonin at a subcellular level in human platelets.Intact human platelets were incubated with 10-5 M concentrations of either serotonin (5HT) or 4,6 difluoroserotonin (DF5HT)2 for 30 minutes at 37°C. Following the incubation period, air-dried whole mounts3 were prepared on 200 mesh copper grids coated with collodion and carbon. Individual platelets were examined at 80 kv in the STEM mode (10 nm spot size), utilizing a Jeol 100B microscope equipped with a field emission gun, a scanning attachment, an electron spectrometer, and a Kevex analysis recording system.

scholarly journals Chemical Fingerprinting of Polymers Using Electron Energy-Loss Spectroscopy

ACS Omega ◽  
2021 ◽  
Author(s):  
Ruchi Pal ◽  
Laure Bourgeois ◽  
Matthew Weyland ◽  
Arun K. Sikder ◽  
Kei Saito ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Chemical Fingerprinting ◽  
Electron Energy Loss

Data Acquisition and Handling Unit for a Quantitative Use of Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 232-233 ◽  
Author(s):  
P. Trebbia ◽  
P. Ballongue ◽  
C. Colliex
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Single Channel ◽  
Detection System ◽  
Surface Barrier ◽  
Solid State Detector ◽  
Electrostatic Mirror ◽  
Electron Energy Loss

An effective use of electron energy loss spectroscopy for chemical characterization of selected areas in the electron microscope can only be achieved with the development of quantitative measurements capabilities.The experimental assembly, which is sketched in Fig.l, has therefore been carried out. It comprises four main elements.The analytical transmission electron microscope is a conventional microscope fitted with a Castaing and Henry dispersive unit (magnetic prism and electrostatic mirror). Recent modifications include the improvement of the vacuum in the specimen chamber (below 10-6 torr) and the adaptation of a new electrostatic mirror.The detection system, similar to the one described by Hermann et al (1), is located in a separate chamber below the fluorescent screen which visualizes the energy loss spectrum. Variable apertures select the electrons, which have lost an energy AE within an energy window smaller than 1 eV, in front of a surface barrier solid state detector RTC BPY 52 100 S.Q. The saw tooth signal delivered by a charge sensitive preamplifier (decay time of 5.10-5 S) is amplified, shaped into a gaussian profile through an active filter and counted by a single channel analyser.

Trends in Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 228-229
Author(s):  
C. Colliex ◽  
P. Trebbia
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Analytical Technique ◽  
Recent Developments ◽  
Quantitative Results ◽  
Electron Microscopes ◽  
Electron Energy Loss ◽  
Primary Electrons

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.

Signal/Noise Ratio and Elemental Detectivity by Eels

1982 ◽  
Vol 40 ◽  
pp. 488-489
Author(s):  
R. F. Egerton
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Elemental Analysis ◽  
Electron Energy Loss Spectroscopy ◽  
Emission Spectroscopy ◽  
X Ray ◽  
Signal Noise ◽  
Characteristic Signal ◽  
Noise Ratio ◽  
Electron Energy Loss

An important parameter governing the sensitivity and accuracy of elemental analysis by electron energy-loss spectroscopy (EELS) or by X-ray emission spectroscopy is the signal/noise ratio of the characteristic signal.

Quantitative Electron Energy Loss Mapping

1985 ◽  
Vol 43 ◽  
pp. 404-405
Author(s):  
R.D. Leapman ◽  
C.R. Swyt
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Elemental Concentration ◽  
Core Loss ◽  
Elemental Distribution ◽  
Electron Energy Loss

The intensity of a characteristic electron energy loss spectroscopy (EELS) image does not, in general, directly reflect the elemental concentration. In fact, the raw core loss image can give a misleading impression of the elemental distribution. This is because the measured core edge signal depends on the amount of plural scattering which can vary significantly from region to region in a sample. Here, we show how the method for quantifying spectra due to Egerton et al. can be extended to maps.

Stopping-power determination for compound by EELS

1994 ◽  
Vol 52 ◽  
pp. 948-949 ◽  
Author(s):  
David C. Joy ◽  
Suichu Luo ◽  
John R. Dunlap ◽  
Dick Williams ◽  
Siqi Cao
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Average Energy ◽  
Stopping Power ◽  
Accurate Information ◽  
Power Calculation ◽  
Coulomb Collisions ◽  
Electron Energy Loss

In Physics, Chemistry, Materials Science, Biology and Medicine, it is very important to have accurate information about the stopping power of various media for electrons, that is the average energy loss per unit pathlength due to inelastic Coulomb collisions with atomic electrons of the specimen along their trajectories. Techniques such as photoemission spectroscopy, Auger electron spectroscopy, and electron energy loss spectroscopy have been used in the measurements of electron-solid interaction. In this paper we present a comprehensive technique which combines experimental and theoretical work to determine the electron stopping power for various materials by electron energy loss spectroscopy (EELS ). As an example, we measured stopping power for Si, C, and their compound SiC. The method, results and discussion are described briefly as below.The stopping power calculation is based on the modified Bethe formula at low energy:where Neff and Ieff are the effective values of the mean ionization potential, and the number of electrons participating in the process respectively. Neff and Ieff can be obtained from the sum rule relations as we discussed before3 using the energy loss function Im(−1/ε).

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