Absorption of Iodine by Polymers and Electrochemical Response of Polymer Film in Aqueous Solution of Iodine

Abstract

ABSTRACT:Isotherms for absorption of iodine by various polymers have been measured at 25°C in aqueous media. Poly(3-vinyl-10-methylphenothiazine) (PVMP), poly(4-vinylpyridine), and poly(tetramethylene ether glycol) absorb 3.0 g, 2.3 g, and 1.8 g of iodine, respectively, per 1.0 g of the polymer when dipped in a 0.05 M aqueous solution of 12 containing KI at 25°C. 6-Nylon, poly(vinyl alcohol), poly(acrylonitrile), poly(acrylamide) absorb 1.7 g, 1.5 g, 1.2 g, and 0.82 g of iodine, respectively, per 1.0 g of the polymer when dipped in a 0.10 M aqueous solution of 12 under the same conditions. Except for 6-nylon, the dependence of the amount of absorbed iodine on [12] K obeys a Langmuir-type equation obtained assuming the equilibrium, 12 +polymer=='" 12.-polymer complex. The equilibrium constant K ranges from 13 M-1 (for poly(vinyl alcohol)) through 53 M-1 (for PVMP). Cyclic voltammograms obtained using a polymer electrode coated on a Pt wire show the occurrence of smooth oxidation and reduction of 1-and 12 , respectively, on the surface of the polymer electrode and inside of the polymer electrode.

Iodine Doping of Poly(thiophene-2,5-diyl) and Poly(3-alkylthiophene-2,5-diyl)s in Aqueous Media

“…The concentration of iodine in the remaining aqueous solution was determined by titration with an aqueous solution of Na 2 S 2 0 3 • The amount of iodine absorbed by the polymer was calculated from the difference between the initial concentration of iodine and its final concentration after absorption by the polymer, similar to the method reported in the literature. 13 For the sample obtained with P3HexTh(Fe) at [I 2 ] = 0.090 M, the amount of iodine thus estimated (I 2 /monomer unit= 0.16) roughly agrees with data of the elemental analysis: Found: C, 57.9; H, 7.1; I, 16.8%. Calcd.…”

Molecular iodine/polymer complexes

“…Sukawa et al [210] reported that the sorp tion isotherm of molecular iodine by nylon6 was in accordance with the Langmuir model, as were those of PVA, poly(acrylamide), poly(4vinylpyridine), poly(tetramethylene ether glycol), poly(acrylonitrile), and poly(3vinyl10methylphenothiazine).…”

“…The iodine adsorption from dipping the nylon in acetone was not Langmuirtype, but that from exposure to iodine vapor showed a pseudoLangmuir behavior. The same isotherm Langmuir absorption was advanced for I 2 nylon6, prepared by immersion of nylon6 into aqueous solution of I 2 /KI at 25°C, by Sukawa et al [210]. Kang and Lee [211], Jeong et al [212] and Shin et al [213] studied the behavior of iodinated nylon6 before (IBF) and after film forming (IAF).…”

Polymeric Iodophors: Preparation, Properties, and Biomedical Applications

“…Other polymers, such as poly(3-vinyl-10-methylphenothiazine), poly(4-vinylpyridine), and poly(tetramethylene ether) glycol, were tested for iodine absorption [ 61 ]. Poly(4-vinylpyridine) and poly(tetramethylene ether) glycol absorbed more than 0.5 mol of I 2 per monomeric unit.…”