Studying water transport to improve the corrosion-prevention properties of more environmentally friendly coatings
21 May 2026 - Rosie de Laune
To understand the behaviour of water-borne coatings used to prevent corrosion, researchers from TU Delft and TU Eindhoven universities in The Netherlands, ISIS and BASF used Small Angle Neutron Scattering to study the way water interacts with the coatings.
Challenge
Anti-corrosion coatings protect surfaces by forming a barrier against moisture, chemicals, and other environmental factors. They are crucial in industries such as marine and oil and gas to prevent costly damage. This is particularly important in countries like the UK, where weather conditions can be both harsh and variable, and so coatings are essential for maintaining outdoor industrial structures.
Traditional solvent-borne coatings contain compounds that can be damaging to the environment and to those applying them. To reduce the concentration of these compounds, water-based coatings have been developed. Although more environmentally friendly, these water-borne coatings would benefit from a deeper mechanistic understanding of film formation and behaviour, which would help extend the range of corrosive environments in which they can be applied.
Solution
One of the main parameters affecting the performance of the coatings is water diffusion and absorption capacity. In this study, published in Langmuir, researchers from TU Delft and TU Eindhoven in The Netherlands collaborated with scientists at ISIS and industrial partner BASF. They studied how water is transported through model coatings using dynamic vapor sorption, and Small Angle Neutron Scattering (SANS) on the Larmor instrument at ISIS.
These water-based coatings are made from aqueous dispersion of polymer nanoparticles, often accompanied by inorganic particles. The group were able to use SANS and computational modelling to observe how the distribution of water changed within the films over time as function of well controlled coating parameters.
“Small-angle scattering techniques such as SANS are particularly powerful for studying the nanoscale structure of these coatings due to their sensitivity in the relevant size range. Our results highlight a complex structure of water transport pathways that vary with the dispersion parameters such as the size of the nanoparticles and that controls water diffusion,” said project leader Professor Dr Santiago Garcia from the TU Delft.
This opens the possibility to further improve water-based coatings by tailoring the water transport pathways to specific applications, thereby increasing their applicability in anti-corrosion coatings.
Researchers from BASF
Benefits
They found that films of coatings made from larger nanoparticles transported water in between the particles, whereas decreasing the colloid size led to the formation of larger water transport channels. These different water pathways explained the macroscopic trends they saw in water absorption and water affinity observed through other techniques.
Even though the nanoparticle size is not the only factor affecting the structure of a coating and its performance, shedding light on the influence of size on the water transport offers unique information to understand the anti-corrosion behaviour of water-based coatings.
“This opens the possibility to further improve water-based coatings by tailoring the water transport pathways to specific applications, thereby increasing their applicability in anti-corrosion coatings,” reported BASF researchers.
The full paper can be found at DOI: 10.1021/acs.langmuir.5c05519 (open access from October 2026) and on the TU Delft repository.
