Corrosion Inhibition Studies of Electroactive Nanospheres Synthesized via Ozone Oxidation

A.J. Suryawanshi, V. Johnston Gelling
North Dakota State University, US

Keywords: corrosion inhibition, electroactive nanospheres

Summary:

Nanostructures of conducting polymers (CPN), such as polyaniline (PANI) and polypyrrole (PPy), have been synthesized and characterized extensively during the past few years. PANI and Ppy nanospheres have traditionally been formed using soft templates, such as surfactant micelles, or hard templates, such as anodized aluminum oxide (AAO). Templates provide stability and groundwork from which the polymer can grow, but the templates add undesirable expense to the process and can change the properties of the nanoparticles by integration of the template material into the CPNs or by acting as a dopant. Several template free processes known as self assembly have been used to produce CPNs. Since self assembly techniques do not use templates for stability, preventing agglomeration becomes an important task for researchers when synthesizing and processing colloidal dispersions. In this study, the template free synthesis was studied of self-assembled, stable PANI and PPy nanospheres formed during exposure to ozone. The research builds upon the recently published work by this group detailing the synthesis of nanospheres of Ppy which have been shown to display high uniformity of size and shape as well as an ability to withstand agglomeration for long periods of time. This synthesis is unique because the reaction solution consists solely of the monomer, ozone, and water and the byproducts are only water and oxygen. The nanospheres were initially characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and UV VIS spectroscopy. More recently, the nanospheres have been further studied for corrosion inhibition properties using multiple electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV).