Did you know that the cost of corrosion to the world economy is estimated to be in excess of
New technologies for the early detection and non-destructive evaluation of corrosion could alleviate some of this financial burden and contribute towards higher infrastructure safety standards in line with the United Nations Sustainable Development Goals (SDGs).
A project by researchers from the Luminescent Sensors and Molecular Logic Gates Laboratory in the Department of Chemistry within the Faculty of Science demonstrates a proof-of-concept for the early detection of corrosion with fluorescent molecules in a polyurethane coating. The study is documented in the open access journal Materials Advances published by the Royal Society of Chemistry.
The research was performed by Glenn Scerri (2018) and Jake Spiteri (2017) in part fulfilment of their Master of Science degrees under the supervision of Prof. David C. Magri.
The researchers report the first-ever molecular-logic based approach to the early detection of corrosion. Designed with a built-in AND logic function, the molecules detect high acidity (pH) and high oxidising (pE) conditions simultaneously.
The molecules were mixed in a polyurethane coating and painted onto mild steel strips, which were scratched and placed either in a brine solution (NaCl) to accelerate corrosion or in deionised water as a control. In the brine solution, corrosion was detected in 90 minutes by the appearance of a green emission while in deionised water there was no evidence of corrosion.
To detect the corrosion the samples were first irradiated with a light source. The study exemplifies a method of detecting the onset of corrosion long before a metal surface suffers any permanent damage.
Their research has been nationally recognised by a Malta Science Innovation Award (Premju għall-Innovazzjoni Xjentifika), and internationally recognised by a World Intellectual Property Organisation (WIPO) medal. It was also granted UK patent GB2533166.
The research was financially supported by the Endeavour Scholarship Scheme, part-financed by the EU ESF - Operational Programme II - Cohesion Policy 2014-2020, and the TAKEOFF Maritime Seed Award (MarSA) Proof of Concept Fund (2017) financed by the Ministry for Transport, Infrastructure and Capital Projects and administered by the Knowledge Transfer Office (KTO) of the University of Malta.
The journal article may be read in its entirety online.
[Figure: Confocal microscope images of a polyurethane coating on mild steel doped with a smart molecule communicating the onset of corrosion by a green fluorescence]