title: Lewis Acid Based Sorption of Trace Amounts of RuCl3 by Polyaniline.
abstract: A sorption process of RuCl3 in phosphate buffer by polyaniline (PANI) powder chemically synthesized from phosphoric acid was spectrophotometrically monitored as a function of time. It was determined that the sorption process follows the Langmuir and Freundlich isotherms, and their constants were evaluated. It was determined that chemisorption was the rate-controlling step. By conducting detailed studies, we assigned the chemisorption to Lewis acid based interactions of the sorbent electron pair localized at the benzenoid amine (-NH2) and quinoid imine (═NH) groups, with the sorbate, RuCl3, as the electron acceptor. The stability of the interaction over a period of ∼1 week showed that the presence of the Ru(III) in the PANI matrix reverses its state from emeraldine base to emeraldine salt, resulting in a change of conductivity. The partial electron donor based charge transfer is a slow process as compared to the sorption process involving Brønsted acid doping.
authors.affiliation: School of Chemistry & Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Harbottle
authors.affiliation: School of Chemistry & Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Hira
authors.affiliation: School of Chemistry & Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
authors.forename: Mira
authors.initials: M
authors.lastname: Josowicz
authors.affiliation: School of Chemistry & Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
authors.forename: Jiří
authors.initials: J
authors.lastname: Janata