Conformational transitions of a weak polyampholyte

Handle URI:
http://hdl.handle.net/10754/346739
Title:
Conformational transitions of a weak polyampholyte
Authors:
Narayanan Nair, Arun Kumar; Uyaver, Sahin; Sun, Shuyu ( 0000-0002-3078-864X )
Abstract:
Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.
KAUST Department:
Computational Transport Phenomena Lab; Physical Sciences and Engineering (PSE) Division
Citation:
Conformational transitions of a weak polyampholyte 2014, 141 (13):134905 The Journal of Chemical Physics
Publisher:
AIP Publishing
Journal:
The Journal of Chemical Physics
Issue Date:
7-Oct-2014
DOI:
10.1063/1.4897161
Type:
Article
ISSN:
0021-9606; 1089-7690
Additional Links:
http://scitation.aip.org/content/aip/journal/jcp/141/13/10.1063/1.4897161
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.authorUyaver, Sahinen
dc.contributor.authorSun, Shuyuen
dc.date.accessioned2015-03-17T06:00:11Zen
dc.date.available2015-03-17T06:00:11Zen
dc.date.issued2014-10-07en
dc.identifier.citationConformational transitions of a weak polyampholyte 2014, 141 (13):134905 The Journal of Chemical Physicsen
dc.identifier.issn0021-9606en
dc.identifier.issn1089-7690en
dc.identifier.doi10.1063/1.4897161en
dc.identifier.urihttp://hdl.handle.net/10754/346739en
dc.description.abstractUsing grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.en
dc.publisherAIP Publishingen
dc.relation.urlhttp://scitation.aip.org/content/aip/journal/jcp/141/13/10.1063/1.4897161en
dc.rightsArchived with thanks to The Journal of Chemical Physicsen
dc.titleConformational transitions of a weak polyampholyteen
dc.typeArticleen
dc.contributor.departmentComputational Transport Phenomena Laben
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalThe Journal of Chemical Physicsen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionIstanbul Commerce University, Faculty of Applied Sciences, Istanbul, Turkeyen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorSun, Shuyuen
kaust.authorNarayanan Nair, Arun Kumaren
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