Chain-Folding Structure of a Semicrystalline Polymer in Bulk Crystals Determined by13C–13C Double Quantum NMR

2013 ◽  
Vol 2 (6) ◽  
pp. 501-505 ◽  
Author(s):  
You-lee Hong ◽  
Toshikazu Miyoshi
Keyword(s):  
Semicrystalline Polymer ◽  
Double Quantum ◽  
Bulk Crystals ◽  
Chain Folding ◽  
Folding Structure

Elucidation of the Chain-Folding Structure of a Semicrystalline Polymer in Single Crystals by Solid-State NMR

2014 ◽  
Vol 3 (6) ◽  
pp. 556-559 ◽  
Author(s):  
You-lee Hong ◽  
Toshikazu Miyoshi
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Solid State Nmr ◽  
Semicrystalline Polymer ◽  
Chain Folding ◽  
Folding Structure

Determination of Chain-Folding Structure of Isotactic Polypropylene in Melt-Grown α Crystals by 13C–13C Double Quantum NMR and Selective Isotopic Labeling

2015 ◽  
Vol 48 (16) ◽  
pp. 5752-5760 ◽  
Author(s):  
Zhen Li ◽  
You-lee Hong ◽  
Shichen Yuan ◽  
Jia Kang ◽  
Akihiro Kamimura ◽  
...  
Keyword(s):  
Isotactic Polypropylene ◽  
Isotopic Labeling ◽  
Double Quantum ◽  
Chain Folding ◽  
Folding Structure

An investigation on the chain-folding structure of an ethylene–propylene copolymer by selective degradation

1975 ◽  
Vol 13 (12) ◽  
pp. 2281-2288 ◽  
Author(s):  
G. N. Patel ◽  
A. Keller ◽  
E. Martuscelli
Keyword(s):  
Ethylene Propylene ◽  
Chain Folding ◽  
Selective Degradation ◽  
Folding Structure

Chain Trajectory and Crystallization Mechanism of a Semicrystalline Polymer in Melt- and Solution-Grown Crystals As Studied Using 13C–13C Double-Quantum NMR

2015 ◽  
Vol 48 (10) ◽  
pp. 3282-3293 ◽  
Author(s):  
You-lee Hong ◽  
Tadanori Koga ◽  
Toshikazu Miyoshi
Keyword(s):  
Semicrystalline Polymer ◽  
Crystallization Mechanism ◽  
Double Quantum

A New Defect in Polyethylene Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 70-71
Author(s):  
E. L. Thomas ◽  
S. L. Sass
Keyword(s):  
Single Crystals ◽  
Screw Dislocation ◽  
Small Distance ◽  
Dipole Model ◽  
Dislocation Dipole ◽  
Chain Folding ◽  
Black And White ◽  
Polymer Crystal ◽  
Different Types

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.

Lattice imaging and pore structure of β ferric oxyhydroxide

1978 ◽  
Vol 36 (1) ◽  
pp. 264-265
Author(s):  
T. Baird ◽  
J.R. Fryer ◽  
S.T. Galbraith
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bulk Material ◽  
Model Structure ◽  
Bulk Crystals ◽  
Lattice Imaging ◽  
Thin Sections ◽  
Ferric Oxyhydroxide ◽  
Resolution Electron ◽  
Hydrolysis Of

Introduction Previously we had suggested (l) that the striations observed in the pod shaped crystals of β FeOOH were an artefact of imaging in the electron microscope. Contrary to this adsorption measurements on bulk material had indicated the presence of some porosity and Gallagher (2) had proposed a model structure - based on the hollandite structure - showing the hollandite rods forming the sides of 30Å pores running the length of the crystal. Low resolution electron microscopy by Watson (3) on sectioned crystals embedded in methylmethacrylate had tended to support the existence of such pores.We have applied modern high resolution techniques to the bulk crystals and thin sections of them without confirming these earlier postulatesExperimental β FeOOH was prepared by room temperature hydrolysis of 0.01M solutions of FeCl3.6H2O, The precipitate was washed, dried in air, and embedded in Scandiplast resin. The sections were out on an LKB III Ultramicrotome to a thickness of about 500Å.

High-resolution gold labeling

1993 ◽  
Vol 51 ◽  
pp. 330-331
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya ◽  
Kyra Carbone ◽  
Martha Simon ◽  
Beth Lin ◽  
...  
Keyword(s):  
Dihydrofolate Reductase ◽  
Polypeptide Chain ◽  
External Surface ◽  
Gold Cluster ◽  
Macromolecular Complex ◽  
Gold Compound ◽  
Central Cavity ◽  
Chain Folding ◽  
E Coli ◽  
Chaperonin Groel

A recently developed 1.4 nm gold cluster has been found to be useful in labeling macromolecular sites to 1-3 nm resolution. The gold compound is organically derivatized to contain a monofunctional arm for covalent linking to biomolecules. This may be used to mark a specific site on a structure, or to first label a component and then reassemble a multicomponent macromolecular complex. Two examples are given here: the chaperonin groEL and ribosomes.Chaperonins are essential oligomeric complexes that mediate nascent polypeptide chain folding to produce active proteins. The E. coli chaperonin, groEL, has two stacked rings with a central hole ∽6 nm in diameter. The protein dihydrofolate reductase (DHFR) is a small protein that has been used in chain folding experiments, and serves as a model substrate for groEL. By labeling the DHFR with gold, its position with respect to the groEL complex can be followed. In particular, it was sought to determine if DHFR refolds on the external surface of the groEL complex, or whether it interacts in the central cavity.

High resolution solution state double quantum spectroscopy of two-spin-1 AX systems and mimics

1997 ◽  
Vol 90 (5) ◽  
pp. 855-868 ◽  
Author(s):  
S.VENKATA RAMAN ◽  
N. CHANDRAKUMAR
Keyword(s):  
High Resolution ◽  
Double Quantum ◽  
Solution State

Double excitation of Nd3+ pairs in LaF3 by two step and double quantum processes

1984 ◽  
Vol 45 (9) ◽  
pp. 1533-1541 ◽  
Author(s):  
R. Buisson ◽  
J.Q. Liu ◽  
J.C. Vial
Keyword(s):  
Double Quantum ◽  
Quantum Processes ◽  
Double Excitation

Functional MRI Based on Intermolecular Double-Quantum Coherences (iDQC) at 3 Tesla

2004 ◽  
Vol 35 (03) ◽  
Author(s):  
A Schäfer ◽  
HE Möller
Keyword(s):  
Functional Mri ◽  
3 Tesla ◽  
Double Quantum
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