Complexation Behavior of Polyelectrolytes and Polyampholytes

Handle URI:
http://hdl.handle.net/10754/625276
Title:
Complexation Behavior of Polyelectrolytes and Polyampholytes
Authors:
Narayanan Nair, Arun Kumar; Martinez Jimenez, Arturo ( 0000-0003-0710-8017 ) ; Sun, Shuyu ( 0000-0002-3078-864X )
Abstract:
We perform grand canonical Monte Carlo simulations to study the pH titrations of isolated polyampholytes and polyelectrolyte-polyampholyte complexes in dilute solutions. Our simulations indicate that the electrostatic interactions promote the coexistence of opposite charges along the polyampholyte chain during titration. The repulsion between excess charges typically dominates the electrostatic interaction and leads to polymer stretching. Salt ions can screen the repulsion between excess charges as well as the fluctuation-induced attraction between opposite charges, and therefore make the variation between titration curves of polyampholytes and the ideal (no electrostatic interactions) curves less significant. We observe that this screening of charge repulsion decreases the chain size. The presence of pearl-necklace configuration of polyampholytes is diminished by the addition of salt. Similar simulations for the polyelectrolyte-polyampholyte system show that the resulting complexes are generally stable in the low pH region. In comparison to ideal case, electrostatic interactions strongly influence the acid-base properties of polyampholyte chains in the adsorbed state by reducing the presence of the coexistence domain of both positive and negative charges in the titration curves. We attribute the complex formation between polyelectrolyte and polyampholyte chains in the high pH region to, e.g., the high salt content. The pH variation leads to abrupt transition between adsorbed and desorbed states. Independent of charge sequence, a polyampholyte chain in a complex is usually located at one of the ends of the polyelectrolyte chain.
KAUST Department:
Computational Transport Phenomena Lab; Physical Sciences and Engineering (PSE) Division
Citation:
Narayanan Nair AK, Martinez Jimenez A, Sun S (2017) Complexation Behavior of Polyelectrolytes and Polyampholytes. The Journal of Physical Chemistry B. Available: http://dx.doi.org/10.1021/acs.jpcb.7b04582.
Publisher:
American Chemical Society (ACS)
Journal:
The Journal of Physical Chemistry B
Issue Date:
25-Jul-2017
DOI:
10.1021/acs.jpcb.7b04582
Type:
Article
ISSN:
1520-6106; 1520-5207
Sponsors:
The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST), Kingdom of Saudi Arabia. A. M. J. and A. K. N. N. gratefully acknowledge computational facilities provided at KAUST.
Additional Links:
http://pubs.acs.org/doi/abs/10.1021/acs.jpcb.7b04582
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Computational Transport Phenomena Lab

Full metadata record

DC FieldValue Language
dc.contributor.authorNarayanan Nair, Arun Kumaren
dc.contributor.authorMartinez Jimenez, Arturoen
dc.contributor.authorSun, Shuyuen
dc.date.accessioned2017-07-31T12:54:35Z-
dc.date.available2017-07-31T12:54:35Z-
dc.date.issued2017-07-25en
dc.identifier.citationNarayanan Nair AK, Martinez Jimenez A, Sun S (2017) Complexation Behavior of Polyelectrolytes and Polyampholytes. The Journal of Physical Chemistry B. Available: http://dx.doi.org/10.1021/acs.jpcb.7b04582.en
dc.identifier.issn1520-6106en
dc.identifier.issn1520-5207en
dc.identifier.doi10.1021/acs.jpcb.7b04582en
dc.identifier.urihttp://hdl.handle.net/10754/625276-
dc.description.abstractWe perform grand canonical Monte Carlo simulations to study the pH titrations of isolated polyampholytes and polyelectrolyte-polyampholyte complexes in dilute solutions. Our simulations indicate that the electrostatic interactions promote the coexistence of opposite charges along the polyampholyte chain during titration. The repulsion between excess charges typically dominates the electrostatic interaction and leads to polymer stretching. Salt ions can screen the repulsion between excess charges as well as the fluctuation-induced attraction between opposite charges, and therefore make the variation between titration curves of polyampholytes and the ideal (no electrostatic interactions) curves less significant. We observe that this screening of charge repulsion decreases the chain size. The presence of pearl-necklace configuration of polyampholytes is diminished by the addition of salt. Similar simulations for the polyelectrolyte-polyampholyte system show that the resulting complexes are generally stable in the low pH region. In comparison to ideal case, electrostatic interactions strongly influence the acid-base properties of polyampholyte chains in the adsorbed state by reducing the presence of the coexistence domain of both positive and negative charges in the titration curves. We attribute the complex formation between polyelectrolyte and polyampholyte chains in the high pH region to, e.g., the high salt content. The pH variation leads to abrupt transition between adsorbed and desorbed states. Independent of charge sequence, a polyampholyte chain in a complex is usually located at one of the ends of the polyelectrolyte chain.en
dc.description.sponsorshipThe research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST), Kingdom of Saudi Arabia. A. M. J. and A. K. N. N. gratefully acknowledge computational facilities provided at KAUST.en
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/abs/10.1021/acs.jpcb.7b04582en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry B, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.jpcb.7b04582.en
dc.titleComplexation Behavior of Polyelectrolytes and Polyampholytesen
dc.typeArticleen
dc.contributor.departmentComputational Transport Phenomena Laben
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalThe Journal of Physical Chemistry Ben
dc.eprint.versionPost-printen
kaust.authorNarayanan Nair, Arun Kumaren
kaust.authorMartinez Jimenez, Arturoen
kaust.authorSun, Shuyuen
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