Radiolytic Method as a Novel Approach for the Synthesis of Nanostructured Conducting Polypyrrole

Abstract

In this study, a novel and extremely facile method for the synthesis of conducting polypyrrole (PPy) was achieved in aqueous solution. This radiolytic method is totally free of template and environmentally friendly compared with traditional chemical methods. According to ultraviolet-visible (UV-vis) spectroscopy and Fourier transform infrared (FTIR) spectroscopy analysis, pyrrole (Py) monomers were polymerized into PPy thanks to their oxidation by HO(•) radicals produced by the radiolysis of water when exposed to γ irradiation. The morphology of PPy was characterized by cryo-transmission electron microscopy (cryo-TEM) in aqueous solution and by scanning electron microscopy (SEM) after deposition. In an original way, high-resolution atomic force microscopy, coupled with infrared nanospectroscopy, was used to probe the local chemical composition of PPy nanostructures. The results demonstrated that spherical and chaplet-like PPy nanostructures were formed by γ-radiolysis. Thermogravimetric analysis (TGA) and electronic conductivity measurements showed that radiosynthesized PPy had good thermal stability and an electrical conductivity higher than that of chemically synthesized PPy.

An alternative radiolytic route for synthesizing conducting polymers in an organic solvent

“…14 Apart from the traditional methods of polymers synthesis, ionizing radiation induced polymerization by g-rays or accelerated electrons is not commonly used in the field of CP synthesis. 15 In previous studies, our group has developed a new methodology based on radiation chemistry to polymerize some of those conducting polymers in aqueous solutions [16][17][18][19] thanks to the oxidation of dissolved organic monomers by oxidizing radicals in situ produced in the medium during water radiolysis. Additionally, pulse radiolysis was used to study and to understand the growth mechanism of PEDOT polymers initiated by these radicals in aqueous solution.…”

Monodisperse Polypyrrole Nanoparticles Prepared via γ-Ray Radiolysis of Water: An Efficient Near-Infrared Photothermal Agent for Cancer Therapy

“…A lot of work have indicated that ·OH or H 2 O 2 can effectively initiate the oxidative polymerization of Py in an aqueous system under appropriate conditions. [11a,13] Commonly, H 2 O 2 or ·OH is introduced either directly or obtained indirectly by utilizing some chemical reactions. But it is well‐known that ·OH and H 2 O 2 can also be conveniently in situ produced when an aqueous solution is radiated by γ‐ray because they are the major active products of the radiolysis of water molecules, as well as the reductive active species of H· and e aq − .…”

“…The absorption at 1717 cm −1 should be due to the stretching vibration of CO in the unhydrolyzed ester bonds of PVA and the CO bonds at the pyrrole ring due to the reaction of the β‐C of the pyrrole ring and hydroxyl radicals, as reported in the previous literatures. [11a,18]…”

“…The oxidative species can be utilized to induce some oxidation reactions when the reductive species are eliminated by certain scavengers . For example, Remita and co‐workers have recently studied the synthesis of PPy and poly(3,4‐ethylenedioxythiophene) nanostructures via γ‐ray radiation on the aqueous solution of monomer under N 2 O atmosphere . The role of N 2 O was to eliminate the hydrated electron ( e aq − ) produced by water radiolysis so that the strong oxidative species (·OH) are maintained to induce the polymerization of Py or 3,4‐ethylenedioxythiophene.…”

Metal-dielectric-metal resonators with deep subwavelength dielectric layers increase the near-field SEIRA enhancement

“…Because of the broad applicability of IR spectroscopy and its chemical specificity, PTIR has enabled the characterization of diverse samples including: polymers [49,50], metal-organic frameworks [51], tri-halide perovskites [52,53], bacteria [43,54], cells [55,56], proteins [57] and drugs nanocrystals [58]. Recently our group applied the PTIR technique to measure high resolution absorption spectra and maps in the near-field surrounding PMMA coated of gold ASRRs which enabled the quantification of the SEIRA absorption enhancement with ≈ 100 nm resolution [3].…”