The tube axis and entanglements in polymer melts

Soft Matter ◽  
2014 ◽  
Vol 10 (12) ◽  
pp. 1895 ◽  
Author(s):  
Alexei E. Likhtman
Keyword(s):  
Author(s):  
Murray Stewart ◽  
T.J. Beveridge ◽  
D. Sprott

The archaebacterium Methanospirillum hungatii has a sheath as part of its cell wall which is composed mainly of protein. Treatment with dithiothreitol or NaOH released the intact sheaths and electron micrographs of this material negatively stained with uranyl acetate showed flattened hollow tubes, about 0.5 μm diameter and several microns long, in which the patterns from the top and bottom were superimposed. Single layers, derived from broken tubes, were also seen and were more simply analysed. Figure 1 shows the general appearance of a single layer. There was a faint axial periodicity at 28.5 A, which was stronger at irregular multiples of 28.5 A (3 and 4 times were most common), and fine striations were also seen at about 3° to the tube axis. Low angle electron diffraction patterns (not shown) and optical diffraction patterns (Fig. 2) from these layers showed a complex meridian (as a result of the irregular nature of the repeat along the tube axis) which showed a clear maximum at 28.5 A, consistent with the basic subunit spacing.


1988 ◽  
Vol 3 (4) ◽  
pp. 175-183 ◽  
Author(s):  
H. Janeschitz-Kriegl ◽  
G. Krobath
Keyword(s):  

Soft Matter ◽  
2021 ◽  
Author(s):  
Lin-Lin Chu ◽  
Kaipin Xu ◽  
Robert Graf ◽  
Zhichao Yan ◽  
Junfang Li ◽  
...  

Chain entanglement behaviors were studied by 1H Hahn echo nuclear magnetic resonance (NMR) and 1H double-quantum (DQ) NMR experiments. Poly(ethylene oxide) (PEO) was chosen to investigate the chain entanglement behaviors....


2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Anine L. Borger ◽  
Qian Huang ◽  
Ole Hassager ◽  
Jacob J. K. Kirkensgaard ◽  
Kristoffer Almdal ◽  
...  
Keyword(s):  

1972 ◽  
Vol 50 (5) ◽  
pp. 576-580 ◽  
Author(s):  
Kyosaku Sato ◽  
Alfred Rudin ◽  
K. K. Chee

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