Structure of salted and discharged globules of hydrophobic polyelectrolytes adsorbed from aqueous solutions

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 48; no. 14; pp. 1623 - 1627
• Main Authors: Trotsenko, Oleksandr, Roiter, Yuri, Minko, Sergiy
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.07.2010; Wiley
• Subjects: adsorption; Applied sciences; Aqueous solutions; atomic force microscopy (AFM); Coiling; Coils; Discharge; Exact sciences and technology; Globules; ionic strength; Liquids; Mica; Organic polymers; Physicochemistry of polymers; polyelectrolytes; Properties and characterization; single molecules; Surface properties; adsorption; atomic force microscopy (AFM); Liquid solid adsorption; Radius of gyration; Experimental study; polyelectrolytes; Polyelectrolyte; Ionic strength; Adsorbed state; pH; single molecules; Pyridine(4-vinyl) polymer; Mica; Conformation
• ISSN: 0887-6266; 1099-0488; 1099-0488
• DOI: 10.1002/polb.21970

In this article, we compare structures of protonated poly(2-vinylpyridine) globules (2D compact coils on the surface) adsorbed on the mica surface from aqueous solution when the shrinking is brought about either by discharging the molecules at an elevated pH or by adding monovalent and polyvalent salts. We study the structure of the PE coils using in situ atomic force microscopy experiments in aqueous solutions in a liquid cell. The abrupt coil-to-globule transition caused by pH changes and the discharge of polymer chains resulted in compact globules. If the pH corresponding to extended coil conformation remains unchanged, the coil shrinks due to the added salt. The size of the globule in the latter case corresponds to the unperturbed dimension of the polymer coil. There is no essential difference in the dimensions of the globules as obtained in the presence of monovalent and multivalent counterions for the studied ionic strength.