scholarly journals Highly Anisotropic Rigidity of “Ribbon-like” Polymers: I. Chain Conformation in Dilute Solutions

1996 ◽  
Vol 6 (10) ◽  
pp. 1411-1428 ◽  
Author(s):  
Irina A. Nyrkova ◽  
Alexander N. Semenov ◽  
Jean-Francois Joanny ◽  
Alexei R. Khokhlov
1988 ◽  
Vol 134 ◽  
Author(s):  
Guy C. Berry

ABSTRACTCertain aspects of the physical chemistry of solutions rodlike polymers are reviewed. The range of concentrations includes infinite dilution ([ŋ]c<<l), dilute solutions ([ŋ,]c<l), moderately concentrated solutions (l<[ŋ]c<[ŋ]cNI), and concentrated solutions (c<cN,), where [ŋ] is the intrinsic viscosity and cNI. is the concentration required for a stable nematic phase. Studies of chain conformation are emphasized at infinite dilution, and rheological behavior is emphasized for more concentrated isotropic and nematic solutions. Both theoretical and experimental considerations are included.


Polymer ◽  
2014 ◽  
Vol 55 (25) ◽  
pp. 6539-6545 ◽  
Author(s):  
Yuji Higaki ◽  
Ryosuke Okazaki ◽  
Tatsuya Ishikawa ◽  
Moriya Kikuchi ◽  
Noboru Ohta ◽  
...  

Polymer ◽  
1992 ◽  
Vol 33 (11) ◽  
pp. 2412-2415 ◽  
Author(s):  
Yushu Matsushita ◽  
Kunio Shimizu ◽  
Ichiro Noda ◽  
Taihyun Chang ◽  
Charles C. Han

1999 ◽  
Vol 96 (12) ◽  
pp. 1745-1755
Author(s):  
DAVID L. CEDENO, JINGPING PENG, DOVIE REY
Keyword(s):  

2019 ◽  
Author(s):  
Dennis Bücker ◽  
Annika Sickinger ◽  
Julian D. Ruiz Perez ◽  
Manuel Oestringer ◽  
Stefan Mecking ◽  
...  

Synthetic polymers are mixtures of different length chains, and their chain length and chain conformation is often experimentally characterized by ensemble averages. We demonstrate that Double-Electron-Electron-Resonance (DEER) spectroscopy can reveal the chain length distribution, and chain conformation and flexibility of the individual n-mers in oligo-(9,9-dioctylfluorene) from controlled Suzuki-Miyaura Coupling Polymerization (cSMCP). The required spin-labeled chain ends were introduced efficiently via a TEMPO-substituted initiator and chain terminating agent, respectively, with an in situ catalyst system. Individual precise chain length oligomers as reference materials were obtained by a stepwise approach. Chain length distribution, chain conformation and flexibility can also be accessed within poly(fluorene) nanoparticles.


2020 ◽  
Vol 04 ◽  
Author(s):  
Vigen G. Barkhudaryan ◽  
Gayane V. Ananyan ◽  
Nelli H. Karapetyan

Background: The processes of destruction and crosslinking of macromolecules occur simultaneously under the influence of ultraviolet (UV) radiation in synthetic polymers, dry DNA and their concentrated solutions. Objective: The effect of UV radiation on calf thymus DNA in dilute solutions subjected to UV- irradiation was studied in this work. Method: The calf thymus DNA was studied in dilute solutions using viscometry, absorption spectroscopy and electrophoresis. Results: It was shown, that at a low concentration of DNA in the buffer solution ([DNA] = 85 μg / ml) under the influence of UV radiation, the processes of destruction of macromolecules and an increase in their flexibility predominate, which is accompanied by a gradual decrease in the viscosity of their solution. In addition, due to the low concentration of the solution, intramolecular crosslinking of macromolecules predominates, which also reduces their size and, consequently, the viscosity of the solution. Conclusion: It was concluded, that in dilute DNA solutions, due to the predominance of the processes of intramolecular crosslinking of macromolecules over intermolecular, only constant processes of decreasing the sizes of DNA macromolecules occur. As a result, its solubility remains virtually unchanged during UV irradiation. The described comments are also excellently confirmed by the results of absorption spectroscopy and electrophoresis


1968 ◽  
Vol 33 (12) ◽  
pp. 4248-4263 ◽  
Author(s):  
A. Červenka ◽  
M. Marek ◽  
K. Šolc ◽  
P. Kratochvíl
Keyword(s):  

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