Influence of barnacle cement protein, CP20, on the corrosion behavior of mild steel

• Main Author: Lim, Juventino Binn Binn
• Other Authors: Matteo Seita
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/75396
• Institution: Nanyang Technological University

In every industry, it is important for companies to reduce cost and minimize downtime of their equipment. Profitability of projects are a main concern for companies where a technical or equipment downtime could result in huge losses and more importantly cause pollution to water bodies. In marine and offshore industries, corrosion of structures and equipment is a common sight due to the presence of barnacles. Such corrosion can result in the weakening of structures or equipment, which could potentially shorten the lifespan and even result in catastrophic failure. Barnacles are known to secrete a protein complex, called barnacle cement proteins (BCP), which enables it to adhere to surfaces resulting in corrosion. This protein complex is made up of several proteins with varying molecular weight. Herein, the authors have made a novel discovery that the proteins themselves cause corrosion. This report documents the corrosive effects of one such protein, CP20, on mild steel. It was found that CP20 adsorption occurs instantaneously and corrosion sites appear within minutes. The results reveal that corrosion sites initiated in the initial stages grow in size and coalesce, but new corrosion sites do not form at later stages. In the absence of stirring, corrosion sites were reduced but interestingly, regions experiencing corrosion appeared as bubbles, probably due to gas formation because of the redox process. Based on limited number of sites, initial results point to the direction that ‘favorable sites’ for protein adsorption due to the orientation of the grains might be present. Most intriguingly, increasing the concentration of proteins appeared to have reduced the extent of corrosion which might be partially due to the steric hindrance at the metal-electrolyte interface. Based on these key finding and improvement that could be done on the work, the authors have suggested future work that could shed light into the poorly understood phenomenon: PIC.