title: Donnan potential caused by polyelectrolyte monolayers.
abstract: The Donnan potential is successfully isolated from ion pair potential on a ferrocene-labeled polyelectrolyte (DNA) monolayer. The isolated Donnan potential shifts negatively upon the increase in NaClO4 concentration with a slope of -58.8 mV/decade. With the salt concentration grown up to 1 M, the stretched DNA chains in low salt concentration are found to experience a gradual conformation relaxing process. At salt concentrations higher than 2 M, Donnan breakdown occurs where only the ion pair effect modulates the apparent potential. The apparent formal potential also shows strong dependence on solution pH, which reveals that the charge density in the polyelectrolyte monolayer plays an important role in the establishment of Donnan equilibrium.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering and ‡State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University , 22 Hankou Road, Nanjing 210093, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhao
authors.forename: Chun-Ge
authors.initials: CG
authors.lastname: Yuan
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Ji
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Yu
authors.forename: Feng-Bin
authors.initials: FB
authors.lastname: Wang
authors.forename: Kang
authors.initials: K
authors.lastname: Wang
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Xia
mesh_terms: D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D010472:Perchlorates / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D017670:Sodium Compounds / Q000737:chemistry
chemical_list: D010472:Perchlorates; D011108:Polymers; D017670:Sodium Compounds; C031068:sodium perchlorate