Crystalline Morphology in Thin Films of Natural Rubber: Crystallization under Strain

1965 ◽  
Vol 38 (1) ◽  
pp. 45-57
Author(s):  
E. H. Andrews
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Natural Rubber ◽  
Electron Diffraction Pattern ◽  
High Strain ◽  
Crystalline Morphology ◽  
Fibrillar Morphology ◽  
Strain Axis ◽  
Very High

Abstract The morphology of thin films of natural rubber crystallized under unidirectional strain has been examined in the electron microscope. As strain increases the spherulitic morphology of unstrained films gives way gradually to a fibrillar morphology with crystalline filaments (α filaments) measuring 60 by 250 A˚, growing perpendicular to the strain axis. The nucleation of these filaments is governed by the amount of strain but their rate of growth depends only on temperature and time. At very high strains (>300%) crystallization occurs rapidly allowing no time for filament growth, so that the resulting morphology consists of chains of nuclei (γ filaments) running in the direction of extension. The high strain transition from α to γ filaments is accompanied by no change in the electron diffraction pattern, but the earlier transition from spherulitic to filamentous growth reveals a rotation of the molecular axis into the direction of strain. This appears to correspond to a physical rotation of the α filaments about their direction of growth.

Crystalline morphology in thin films of natural rubber II. Crystallization under strain

1964 ◽  
Vol 277 (1371) ◽  
pp. 562-570 ◽  
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Natural Rubber ◽  
Electron Diffraction Pattern ◽  
High Strain ◽  
Crystalline Morphology ◽  
Fibrillar Morphology ◽  
Strain Axis ◽  
Very High

The morphology of thin films of natural rubber crystallized under unidirectional strain has been examined in the electron microscope. As strain increases the spherulitic morphology of unstrained films gives way gradually to a fibrillar morphology with crystalline filaments (α filaments) measuring 60 by 250 Å, growing perpendicular to the strain axis. The nucleation of these filaments is governed by the amount of strain but their rate of growth depends only on temperature and time. At very high strains ( > 300 %) crystallization occurs rapidly allowing no time for filament growth, so that the resulting morphology consists of chains of nuclei (γ filaments) running in the direction of extension. The high strain transition from α to γ filaments is accompanied by no change in the electron diffraction pattern, but the earlier transition from spherulitic to filamentous growth reveals a rotation of the molecular axis into the direction of strain. This appears to correspond to a physical rotation of the α filaments about their direction of growth.

Spherulite morphology in thin films of natural rubber

1962 ◽  
Vol 270 (1341) ◽  
pp. 232-241 ◽  
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Natural Rubber ◽  
Single Crystals ◽  
Growth Mechanism ◽  
Electron Irradiation ◽  
Electron Diffraction Data ◽  
Dilute Solution ◽  
Spherulite Morphology

Crystalline ‘spherulites’ grown in ultra-thin films of natural rubber at — 26 °C were examined in the electron microscope. The spherulites form hollow domes, like blisters in the film, which collapse under electron irradiation producing remarkable fibre-like patterns of folds and creases. Within the spherulite, crystalline and amorphous regions coexist and the former appear to grow to a preferred thickness of a few hundred Angstroms with the molecular chains oriented perpendicular to the film. The molecules are thus almost certainly folded as in polymer single crystals grown from dilute solution. Electron diffraction data suggest that relatively large regions of the spherulite correspond to single crystals. A growth mechanism for the spherulites is proposed.

Spherulite Morphology in Thin Films of Natural Rubber

1965 ◽  
Vol 38 (1) ◽  
pp. 33-44
Author(s):  
E. H. Andrews
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Natural Rubber ◽  
Single Crystals ◽  
Growth Mechanism ◽  
Electron Irradiation ◽  
Electron Diffraction Data ◽  
Dilute Solution ◽  
Spherulite Morphology

Abstract Crystalline ‘spherulites’ grown in ultra-thin films of natural rubber at − 26° C were examined in the electron microscope. The spherulites form hollow domes, like blisters in the film, which collapse under electron irradiation producing remarkable fiber-like patterns of folds and creases. Within the spherulite, crystalline and amorphous regions coexist and the former appear to grow to a preferred thickness of a few hundred angstroms with the molecular chains oriented perpendicular to the film. The molecules are thus almost certainly folded as in polymer single crystals grown from dilute solution. Electron diffraction data suggest that relatively large regions of the spherulite correspond to single crystals. A growth mechanism for the spherulites is proposed.

scholarly journals Donald William Pashley. 21 April 1927 — 16 May 2009

2010 ◽  
Vol 56 ◽  
pp. 317-340 ◽  
Author(s):  
Bruce A. Joyce ◽  
Michael J. Stowell
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Film Growth ◽  
Epitaxial Thin Films ◽  
Disorder Effects ◽  
Transmission Electron ◽  
Innovative Materials ◽  
Low Dimensional

Donald William (Don) Pashley was one of the most innovative materials scientists of his generation. He was distinguished for his electron diffraction and transmission electron microscope studies of epitaxial thin films, especially for in situ investigations, work that contributed enormously to our understanding of film growth processes. He pioneered the use of moiré patterns to reveal dislocations and other defects. He also made important contributions to long-range disorder effects on semiconductor surfaces and to the structure of low-dimensional semiconductor systems.

Automatic Crystallographic Characterization in a Transmission Electron Microscope: Applications to Twinning Induced Plasticity Steels and Al Thin Films

2013 ◽  
Vol 19 (3) ◽  
pp. 693-697 ◽  
Author(s):  
M. Galceran ◽  
A. Albou ◽  
K. Renard ◽  
M. Coulombier ◽  
P.J. Jacques ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Transmission Electron Microscope ◽  
Microstructural Characterization ◽  
Fine Grained ◽  
Mapping Tool ◽  
Transmission Electron ◽  
Kikuchi Lines ◽  
Diffraction Patterns

AbstractA new automated crystallographic orientation mapping tool in a transmission electron microscope technique, which is based on pattern matching between every acquired electron diffraction pattern and precalculated templates, has been used for the microstructural characterization of nondeformed and deformed aluminum thin films and twinning-induced plasticity steels. The increased spatial resolution and the use of electron diffraction patterns rather than Kikuchi lines make this tool very appropriate to characterize fine grained and deformed microstructures.

Epitaxial Growth of SrTiO3 Thin Films on TiN/Si Substrates Using RF Sputtering

2006 ◽  
Vol 966 ◽  
Author(s):  
Chun Wang ◽  
Mark H Kryder
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Electron Diffraction Pattern ◽  
Rf Sputtering ◽  
Epitaxial Relationship ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTEpitaxial SrTiO3 (001) thin films with a TiN template layer have been deposited on Si(001) single crystal substrates by RF sputtering. The deposited SrTiO3 films show a surface with roughness of 0.66nm. The orientation relationship was determined to be SrTiO3(001)[110]∥TiN(001)[110]∥Si(001)[110]. The microstructure and interface of the multilayer was studied using high resolution transmission electron microscopy (TEM). The electron diffraction pattern confirmed the epitaxial relationship between each layer.

Mechanism of Work Hardening of Mn13 after Asynchronous Cold Rolling

2011 ◽  
Vol 117-119 ◽  
pp. 118-121
Author(s):  
Yan Feng Wang ◽  
Chang Ming Qiu ◽  
Hong Chan Sun
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Cold Rolling ◽  
Electron Diffraction Pattern ◽  
Work Hardening ◽  
Optical Microscope ◽  
Theory And Practice ◽  
X Ray ◽  
Photographic Camera ◽  
Transmission Electron

The hardness of Mn13 can increase if taking asynchronous cold rolling technique .The mechanism of work hardening after asynchronous cold rolling is analyzed in depth by studying the microstructure and electron diffraction pattern with optical microscope, transmission electron microscope and X-ray electron diffract photographic camera. The research will make a contribution to theory and practice of Mn13.

scholarly journals High-angle electron diffraction of frozen hydrated collagen

1976 ◽  
Vol 153 (1) ◽  
pp. 139-140 ◽  
Author(s):  
H Chanzy ◽  
J M Franc ◽  
D Herbage
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Electron Diffraction Pattern ◽  
Collagen Fibrils ◽  
Diffraction Experiment ◽  
High Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Agreement

By using the techniques developed by Taylor et al. [(1975) J. Mol. Biol. 92, 165-167] (freezing of the hydrated specimen before its insertion into the electron microscope and keeping it frozen throughout the diffraction experiment), it was possible to obtain a high-angle electron-diffraction pattern from collagen fibrils. This pattern is in good agreement with that obtained by high-angle X-ray diffraction. Electron diffraction will be very useful to study collagen, because the diffraction pattern from a carefully selected area of one fibril is now feasible.

A distorted 6H structure in an A1-Li-Cu-Mg-Zr- alloy

1987 ◽  
Vol 45 ◽  
pp. 420-421
Author(s):  
J. P. Zhang ◽  
C. Tsurata ◽  
L. D. Marks
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Electron Diffraction Pattern ◽  
Base Alloy ◽  
Stacking Sequence ◽  
Zr Alloy

The powder extracted from a Al-base alloy containing Li, Cu, Mg and Zr was examined in a H9000 electron microscope equipped with ultra-high resolution polepieces having Cs = 0.9mm at 300 KV for HREM studies.Figure 1 is a typical electron diffraction pattern of 6H structure: spots are grouped as six neighbours along c direction. For 00ℓ when ℓ = 6n (n = 0, 1, …) the diffraction spots occur with strong intensities while for 10ℓ, the reflections are almost extinct when ℓ = 6n. The stacking sequence of (001) planes is ABCACB composed by 3R, ABC, and anti 3R, ACB, twinned structures with a = 0.27 nm , c = 1.52 nm. Figure 2 is a structure image in the same direction of Fig.l, which shows the (001) stacking clearly. No twinned structure was observed because the stacking sequence is modified to ABCAB'B, where the C of anti 3R is changed to B’ that is close to B but different.

Intensity distribution of electron diffraction pattern from Ti-14Wt%Mo alloy containing ωphase plate crystal

1990 ◽  
Vol 48 (4) ◽  
pp. 986-987
Author(s):  
Mitsuhiro Awaji ◽  
Hatsujiro Hashimoto ◽  
Eiichi Sukedai ◽  
Fumio Akao
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Electron Diffraction Pattern ◽  
Dynamical Theory ◽  
Β Phase ◽  
Ω Phase ◽  
Microscope Images ◽  
Phase Crystal ◽  
Diffraction Patterns

The study of ω-phase in various alloys such as Ti-Mo, Ti-Cr, Zr-Nb etc. have been carried out so far by electron diffraction and electron microscopy. However, the shape of ω-phase particles has not been fully clarified yet. This is due to the facts that ω-phase is formed in ω-phase crystal, and rather difficult to obtain isolated crystal particles and also that w-phase is produced only by the displacement of atoms in characteristic directions which makes no contrast in the electron microscope images projected along this directions and hence the crosssectional shape can not be studied. Since the intensity of electron diffraction patterns is very sensitive to the amount of ω-phase existing in β-phase, its thickness dependence has been studied in the present paper by using multi-slice dynamical theory of electron diffraction for the various thickness combination of the ω- and β-phases so that the thickness and location of ω-phase can be seen.

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