The performance of hydrophilic moieties in synthesized fluorinated cationic surfactants on corrosion inhibition of carbon steel pipelines

Abstract

Compared with traditional hydrocarbon surfactants, fluorinated surfactants exhibit unique characteristics such as reduced surface tension, enhanced efficacy in reducing interfacial tension, dual hydrophobic and oleophobic nature, increased thermal stability, and superior chemical resistance. These characteristics make them a favorite material for many kinds of applications. This study aims to highlight the synthetic route for three novel cationic fluorinated surfactants (CFS) and applied them in the oilfield as corrosion inhibitors. Characterization of the prepared surfactants took place using different spectroscopic techniques. The influence of hydrophilic moieties on the micellar characteristics of ionic surfactants that have the same hydrophobic fluorinated chains are investigated in this research. Also, an evaluation of the influence of these groups on thermodynamic parameters was carried out.The metal corrosion inhibition efficiency of the CFS was studied in acidic medium by three different techniques, including potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and weight loss procedures, at three different temperature ranges (25, 40, and 60 °C).The achieved results displayed the inhibition efficiency of the metal corrosion that was elevated by increasing both the CFS's concentration and the applied temperature values. The highest level of inhibition, reaching 97.48 %, was achieved at a concentration of 700 parts per million (ppm) and a temperature of 60 °C. Furthermore, it was noticed that the charge transfer resistance value was raised; however, the constant phase element was decreased with increasing the CFS concentrations. The CFS regards an excellent and mixed-type corrosion inhibitor. The adsorption of CFS has agreed the Langmuir's adsorption isotherm and was related to chemisorption. SEM photos show a good CS surface in the presence of CFS versus the absence of them.