Effect of counterions on comb-like polycarboxylate conformation in aqueous solutions. Issue 5 (4th May 2017)

• Record Type: Journal Article
• Authors: Zhang, Qian; Ran, Qianping; Zhao, Hongxia; Shu, Xin; Yang, Yong
• Is Part Of: Journal of dispersion science and technology. Volume 38:Issue 5(2017)
• Page Start: 721
• Page End: 728
• Publication Date: 2017-05-04
• Subjects: Comb-like copolymers -- conformation -- polycarboxylate -- counterions; Emulsions -- Periodicals; Suspensions (Chemistry) -- Periodicals; Emulsions; Suspensions; 541.34
• DOI: 10.1080/01932691.2016.1192043
• Languages: English
• ISSNs: 0193-2691

Abstract

ABSTRACT: Laser light scattering (LLS) and conductivity experiments were performed to investigate the effect of counterions on the conformation of polycarboxylate comb-like copolymers (PCEs) in aqueous solutions. The addition of monovalent ions (i.e., Na + and K + ) to dilute polycarboxylate comb-like copolymer solutions induced a slight shrinking of the molecular chains because of the screening of electrostatic intramolecular repulsion. Varying complexation phenomena, such as the formation of intramolecular complexation at certain Ca 2+ concentrations and a transition between intermolecular and intramolecular complexations at different Ca 2+ concentrations, were closely associated with Ca 2+ concentration. Therefore, Ca 2+ exerted a more complex influence on the conformation of PCEs with side chains containing polyethylene oxide (PEO) with different grafting densities. In addition, various combination types of Ca 2+ with carboxylic groups were confirmed by theoretical simulation. GRAPHICAL ABSTRACT: