التفاصيل البيبلوغرافية
| العنوان: |
Counterion associative behavior with flexible polyelectrolytes. |
| المؤلفون: |
Prabhu, Vivek M., Amis, Eric J., Bossev, Dobrin P., Rosov, Nicholas |
| المصدر: |
Journal of Chemical Physics; 9/1/2004, Vol. 121 Issue 9, p4424-4429, 6p, 1 Chart, 4 Graphs |
| مصطلحات موضوعية: |
ELECTROLYTES, HYDROGEN, DEUTERIUM, STYRENE, POLYMERS, IONS |
| مستخلص: |
At low ionic strength, organic counterions dress a flexible charged polymer as measured directly by small-angle neutron scattering and neutron spin-echo spectroscopy. This dressed state, quantified by the concentration dependence of the static correlation length, illustrates the polymer-counterion coupled nature on the nanometer length scale. The counterions, made visible by selective hydrogen and deuterium labeling, undress from the polymeric template by addition of sodium chloride. The addition of this electrolyte leads to two effects: increased Debye electrostatic screening and decoupled organic counterion-polymer correlations. Neutron spin-echo spectroscopy measures a slowing down of the effective diffusion coefficient of the labeled counterions at the length scale of 8 nm, the static correlation length, indicating the nanosecond counterion dynamics mimics the polymer. These experiments, performed with semidilute solutions of tetramethylammonium poly(styrene sulfonate) [(h-TMA+) d-PSS], apply to relevant biopolymers including single and double stranded DNA and unfolded proteins, which undergo orchestrated dynamics of counterions and chain segments to fold, unfold, and assemble. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
|
Copyright of Journal of Chemical Physics is the property of American Institute of Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
| قاعدة البيانات: |
Complementary Index |
Find this article in full text from Scitation.