Study of Gelatin Copolymer Hydrogel Based Polyaniline and Correlation Between Structure and Reactivity of Substituted Polyaniline Based Gelatin Solution as Gamma Radiation Dosimeters

ABSTRACT Polyaniline and its derivatives based on polymer solution and hydrogels were prepared in situ to be used as colorimetric dosimeters using green nontoxic and cheap polymers as gamma radiation dosimeters. The prepared polymer hydrogel and solutions were characterized by their transparency and were highly applicable for gamma radiation dosimetry. Polymerization was carried out in two systems, based on gelatin solution, and (gelatin/acrylamide/polyvinyl alcohol) (G/PAm/PVA) hydrogel. Different dosimetric parameters, absorption spectra, response curves, sensitivity, G‐value, and relative stability were studied. The two systems showed remarkable colorimetric changes from blue to green and excellent color stability for a long period under different storage conditions of light and dark. The applicable dose range was from 0 up to 40 kGy and 0 up to 15 kGy for the solution and hydrogel system, respectively. Also, Hammett correlation between the structure of PANI and its p‐OCH 3 , p‐CH 3 , p‐OH, and p‐Cl derivatives using the time of radiation exposure instead of reaction rate was investigated through the (σ)‐log k/k 0 plot. The linear plot with slope (ρ) equals to (+1.143) indicated that the sensitivity of (PANI) is enhanced by electron withdrawal substituents. The results obtained confirmed that protonation occurs, which decreases the density of the electrons on the nitrogen atom, facilitating its cleavage by radiation, and leading to fast degradation into lower molecular components.