Molecular composite films of MoS2 and styrene

1991 ◽  
Vol 6 (5) ◽  
pp. 1103-1107 ◽  
Author(s):  
W.M.R. Divigalpitiya ◽  
R.F. Frindt ◽  
S.R. Morrison
Keyword(s):  
Electrical Conductivity ◽  
Organic Molecules ◽  
Composite Films ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
Molecular Layers

Novel composite films with a monolayer of organic molecules included between single molecular layers of MoS2 can be prepared with a recently described technique. Styrene-included MoS2, before and after polymerization, is discussed as an example that exhibits interesting properties. The sensitivity to humidity of the styrene-included MoS2 system is monitored in situ with x-ray diffraction where reversible incorporation and removal of water molecules are observed. Films with an anisotropy of electrical conductivity of about 108 are obtained by polymerizing the monomer between the layers.

scholarly journals In Situ Coherent X-ray Diffraction during Three-Point Bending of a Au Nanowire: Visualization and Quantification

2018 ◽  
Vol 2 (4) ◽  
pp. 24 ◽  
Author(s):  
Anton Davydok ◽  
Thomas Cornelius ◽  
Zhe Ren ◽  
Cedric Leclere ◽  
Gilbert Chahine ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Reciprocal Space ◽  
X Ray Diffraction ◽  
Complex Deformation ◽  
X Ray ◽  
Three Point Bending ◽  
Atomic Force ◽  
Au Nanowire ◽  
Before And After

The three-point bending behavior of a single Au nanowire deformed by an atomic force microscope was monitored by coherent X-ray diffraction using a sub-micrometer sized hard X-ray beam. Three-dimensional reciprocal-space maps were recorded before and after deformation by standard rocking curves and were measured by scanning the energy of the incident X-ray beam during deformation at different loading stages. The mechanical behavior of the nanowire was visualized in reciprocal space and a complex deformation mechanism is described. In addition to the expected bending of the nanowire, torsion was detected. Bending and torsion angles were quantified from the high-resolution diffraction data.

Dehydration and decomposition of pyrophyllite at high pressures: electrical conductivity and X-ray diffraction studies to 5 GPa

1997 ◽  
Vol 34 (6) ◽  
pp. 875-882 ◽  
Author(s):  
Tara L. Hicks ◽  
Richard A. Secco
Keyword(s):  
Electrical Conductivity ◽  
South African ◽  
Pressure Dependence ◽  
High Pressures ◽  
Ionic Conduction ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Dependence Of Conductivity

The dehydration and decomposition of South African pyrophyllite were studied in the pressure range 2.5–5.0 GPa and in the temperature (T) range 295–1473 K using both in situ electrical conductivity measurements and X-ray diffraction studies on the recovered samples. Activation energies for conduction (Qc) vary in the range 0.02–0.07 eV for T ≤ 500 K where the dominant conduction mode is electronic, and Qc is in the range 1.10–1.28 eV for T ≥ 500 K where ionic conduction dominates. Abrupt changes in the isobaric temperature dependence of conductivity mark the onset of dehydration and subsequent decomposition into kyanite plus quartz–coesite. At 2.5 GPa, South African pyrophyllite forms the dehydroxylate phase at 760 K with a pressure dependence of ~30 K/GPa and complete decomposition follows at 1080 K with a pressure dependence of ~41 K/GPa. The resulting pressure–temperature phase diagram is in very good agreement with many previous studies at 1 atm (101.325 kPa).

In-Situ X-ray Diffraction Study of Lithium Intercalation in Nanostructured Anatase Titanium dioxide

1998 ◽  
Vol 536 ◽  
Author(s):  
R. Van de Krol ◽  
E. A. Meulenkamp ◽  
A. Goossens ◽  
J. Schoonman
Keyword(s):  
Phase Transformation ◽  
Maximum Amount ◽  
Lithium Intercalation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
The Difference ◽  
Two Phases ◽  
Reversible Phase

AbstractElectrochemical lithium intercalation in nanostructured anatase TiO2 is investigated with in-situ X-ray diffraction. A complete and reversible phase transformation from tetragonal anatase TiO2 to orthorhombic anatase Li0.5TiO2 is observed. The difference of the XRD spectra before and after insertion can be fitted with the lattice parameters of the two phases as fit parameters. The maximum amount of lithium that can be dissolved in anatase TiO2 before the phase transformation occurs is found to be very small.

scholarly journals In-situhigh-pressure powder X-ray diffraction study of α-zirconium phosphate

2014 ◽  
Vol 70 (3) ◽  
pp. 510-516
Author(s):  
Jennifer E. Readman ◽  
Alistair Lennie ◽  
Joseph A. Hriljac
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Zirconium Phosphate ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
Additional Water ◽  
Diffraction Patterns ◽  
Layered Phosphate

The high-pressure structural chemistry of α-zirconium phosphate, α-Zr(HPO4)2·H2O, was studied usingin-situhigh-pressure diffraction and synchrotron radiation. The layered phosphate was studied under both hydrostatic and non-hydrostatic conditions and Rietveld refinement carried out on the resulting diffraction patterns. It was found that under hydrostatic conditions no uptake of additional water molecules from the pressure-transmitting medium occurred, contrary to what had previously been observed with some zeolite materials and a layered titanium phosphate. Under hydrostatic conditions the sample remained crystalline up to 10 GPa, but under non-hydrostatic conditions the sample amorphized between 7.3 and 9.5 GPa. The calculated bulk modulus,K0= 15.2 GPa, showed the material to be very compressible with the weak linkages in the structure of the type Zr—O—P.

The Application of In Situ 3D X-Ray Diffraction in Annealing Experiments: First Interpretation of Substructure Development in Deformed NaCl

2012 ◽  
Vol 715-716 ◽  
pp. 461-466 ◽  
Author(s):  
Verity Borthwick ◽  
Søren Schmidt ◽  
Sandra Piazolo ◽  
Carsten Gundlach ◽  
Albert Griera ◽  
...  
Keyword(s):  
Subgrain Boundary ◽  
Surface Effects ◽  
Sample Volume ◽  
European Synchrotron Radiation Facility ◽  
X Ray Diffraction ◽  
Boundary Misorientation ◽  
X Ray ◽  
Before And After ◽  
Annealing Experiments

n-situ 3D X-ray diffraction (3DXRD) annealing experiments were conducted at the ID-11 beamline at the European Synchrotron Radiation Facility in Grenoble. This allowed us to non-destructively document and subsequently analyse the development of substructures during heating, without the influence of surface effects. A sample of deformed single crystal halite was heated to between 260-400 °C. Before and after heating a volume of 500 by 500 by 300 μm was mapped using a planar beam, which was translated over the sample volume at intervals of 5-10 µm in the vertical dimension. In the following we present partially reconstructed orientation maps over one layer before and after heating for 240min at 260 °C. Additional small syn-heating maps over a constrained sample rotation of 12-30º. The purpose of this was to illuminate a few reflections from 1 or 2 subgrains and follow their evolution during heating. Preliminary results show that significant changes occurred within the sample volume, for which, surface effects can be excluded. Results show a number of processes, including: i) change in subgrain boundary misorientation angle and ii) subgrain subdivision into areas of similar lattice orientation with new subgrain boundary formation. These results demonstrate that 3DXRD coupled with in-situ heating is a successful non-destructive technique for examining real-time post-deformational annealing in strongly deformed crystalline materials with complicated microstructures.

Assessment of Cleaning Conservation Interventions on Architectural Surfaces Using an Integrated Methodology

2002 ◽  
Vol 712 ◽  
Author(s):  
Antonia Moropoulou ◽  
Ekaterini T. Delegou ◽  
Nicolas P. Avdelidis ◽  
Maria Koui
Keyword(s):  
Historic Buildings ◽  
X Ray Diffraction ◽  
Laboratory Methods ◽  
X Ray ◽  
Integrated Methodology ◽  
Physico Chemical ◽  
Before And After ◽  
Of Greece ◽  
Blasting Method

ABSTRACTIn this work, pilot cleaning interventions applied by a wet micro-blasting method on architectural surfaces of three historic buildings in marble and porous stone were evaluated in situ and in the laboratory. The investigation was performed on characteristic stone surfaces (marbles and porous stone) of the following historic buildings: Athens Academy and National Library of Greece in Athens center polluted urban environment and Bank of Greece in Piraeus marine environment. The materials of the facades were characterized, and the mechanism of decay was diagnosed. In addition, the cleaning method's efficiency was evaluated based on the acceptability of the alteration of the cleaned architectural surfaces. Criteria were both aesthetic and physico-chemical. In particular, the architectural surfaces were examined in situ by the means of fiber optic microscopy, infrared thermography and colorimetry. In the laboratory, methods of investigation were optical microscopy, X-ray diffraction, scanning electron microscopy with energy dispersion by X-ray analysis, mercury intrusion porosimetry, Fourier transform infrared spectroscopy, conductivity and pH measurements. The majority of measurements and analyses were applied before and after the pilot cleaning interventions. Finally, the results of this study contribute to the development of an integrated methodology for the assessment of cleaning interventions applied on architectural surfaces.

scholarly journals Thermal and electrical properties of polyimide/PANI nanofiber composites prepared via in situ polymerization

2018 ◽  
Vol 36 (2) ◽  
pp. 283-287
Author(s):  
Aseel A. Kareem
Keyword(s):  
In Situ Polymerization ◽  
Composite Films ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Nanofiber Composite ◽  
X Ray ◽  
Thermal And Electrical Properties ◽  
Ft Ir ◽  
Thermal Stability Of

Abstract Polyimide/polyaniline nanofiber composites were prepared by in situ polymerization with various weight percentages of polyaniline (PANI) nanofibers. X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), proved the successful preparation of PANI nanofiber composite films. In addition, thermal stability of PI/PANI nanofiber composites was superior relative to PI, having 10 % gravimetric loss in the range of 623 °C to 671 °C and glass transition temperature of 289 °C to 297 °C. Furthermore, the values of the loss tangent tanδ and AC conductivity σAC of the nanocomposite films were notably higher than those of pure polyimide. The addition of 5 wt.% to 15 wt.% PANI nanofiber filler enhanced the activation energy of PI composites from 0.37 eV to 0.34 eV.

scholarly journals Влияние углеродных нанотрубок на электрические и механические свойства хитозановых пленок

2022 ◽  
Vol 92 (3) ◽  
pp. 435
Author(s):  
А.М. Камалов ◽  
В.В Kодолова-Чухонцева ◽  
E.Н Дресвянина ◽  
T.П Масленникова ◽  
И.П Добровольская ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Composite Films ◽  
X Ray Diffraction ◽  
Electronic Components ◽  
Electrical Field ◽  
Field Frequency ◽  
X Ray ◽  
Scanning Electron

Using the methods of X-ray diffraction and scanning electron microscopy, the structure of composite films based on chitosan and single-wall carbon tubes has been studied. It is shown that the introduction of carbon nanotubes leads to the ordering of the chitosan structure. Increase in concentration of nanotubes (from 0 to 3%) causes rise in the value of storage modulus from 3 to 4 GPa (DMA data), increase in electrical conductivity of samples (from 10-11 to 102 S/m), and some changes in their dielectric permittivity (from 5.5. to 26 at an electrical field frequency of 1kHz). Data on the ionic and electronic components of the conductivity of the composite film are presented.

Dehydration and rehydration of vermiculites: I. Phlogopitic Mg-vermiculite

Clay Minerals ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 327-340 ◽  
Author(s):  
H. Graf v. Reichenbach ◽  
J. Beyer
Keyword(s):  
Detailed Analysis ◽  
Slow Heating ◽  
Water Molecules ◽  
Sensitive Detector ◽  
Interlayer Water ◽  
Heating Rates ◽  
X Ray ◽  
Position Sensitive ◽  
Molecular Layers

AbstractDehydration and rehydration of a phlogopitic Mg-vermiculite were studied by thermo-analysis (TG, DSC) and in situ X-ray powder diffractometry. A detailed analysis of the relation between temperature and state of hydration of the vermiculite was rendered possible by use of slow heating rates in combination with a fast-recording position-sensitive detector. The results confirm the existence of a number of definite states of hydration characterized by basal spacings of 1.441,1.429,1.376, 1.165, 1.151,1.002 and 0.926 nm, all of which have already been described in the literature. In addition, so far undetected regular 1 : 1 interstratifications have been found. They formed during those transformations which lead to a change in the number of sheets of interlayer water molecules. These structures exhibit integral series of 00l reflections and d(001) spacings of 2.54 and 2.15 nm for the 2 : 1 and 1 : 0 transitions in the ratio of molecular layers of water, respectively.

Influence of Cu Diffusion on Electrical Transport Properties of Bi0.5Sb1.5Te3

2013 ◽  
Vol 743-744 ◽  
pp. 70-75 ◽  
Author(s):  
Song Chen ◽  
Xin Wang ◽  
Zhi Gang Zou ◽  
Ke Feng Cai
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Electrical Transport ◽  
Impurity Phase ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
Bulk Materials ◽  
Measurement Temperature ◽  
X Ray ◽  
Before And After

Bi0.5Sb1.5Te3 nanoplates from gas induced reduction (GIR) strategy were hot-pressed into bulk materials for thermoelectric properties investigation. During the electrical conductivity and Seebeck coefficient measurements, we found that the Cu from Cu electrodes diffused into samples when the measurement temperature was above 600 K. The phase composition and fracture surface of the samples before and after Cu diffusion were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). We found that the Cu diffusion resulted in the composition deviation and formation of impurity phase, Cu1.8Te. When the electrical conductivity and Seebeck coefficient of the samples were measured again but below 600 K, the samples showed different electrical transport behavior and had enhanced power factors.

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