The different approaches
Nowadays, several new concepts to design and fabricate sustainable coatings have emerged. Among these, bio strategies are based on the recognition that microorganisms do not only accelerate corrosion, named microbiologically influenced corrosion (MIC) or biocorrosion, but can also inhibit or protect against corrosion, what is summarized in the term of microbiologically influenced corrosion inhibition (MICI).
This knowledge has led to suggest microbial-based solutions for metal marine corrosion inhibition. Existing literature proposes different approaches for potentially successful MICI mechanisms.
The case of the protective biofilm
The first approach is a protective biofilm that works primarily as a coating and delivers protection when the metabolic activity reduces corrosion-causing reactions or growth of corrosion-causing organisms. A strong focus of research is now based on the development of these biocoatings, exploring several and simultaneous ways of action:
- Creation of surfaces integrating the behavior/properties of the living organisms on the metallic substrate.
- Incorporation of active biomolecules as functional compounds in coating matrix. The impact of these routes of research is reflected in the several projects that have been funded by the EU in the H2020 program.
The MICOATEC approach
The second MICI mechanism that was reported in scientific literature is the microbially induced formation of deposits (biomineralisation) to protect the material against corrosion: the case of vivianite formation on carbon steel in presence of Geobacter species is a clear illustration of this phenomenon. In stone protection, microbially induced precipitation is already applied in certain industries. However, the vision that this natural phenomena can be explored as a process for the production of anticorrosion solutions represents a big challenge: microbially induced protection still requires a better understanding of the involved processes before thinking about application in full practice.
The new approach proposed in MICOATEC (Microbially Inspired Coating Technology Concept) explores this second mechanism: the main objective is to mimic the natural biomineralization process occurring in marine environment to develop a new technology for the production of anticorrosive solutions.
The project then goes beyond the state of art that currently deals with either the biomimetic reproduction of protective biofilms properties or the incorporation of biocompounds as corrosion inhibitors in surface treatments and coatings. MICOATEC will NOT
intend to mimic the biological properties of protective biofilms but aims to biomimetically replicate the properties of the protective compact layer formed during marine microbial oxidation of the metal surface.
The radical and disruptive vision of MICOATEC is the development of an innovative technology to obtain efficient,
cost effective and sustainable solutions for metallic corrosion protection.