Correlating the surfactant-rich interparticle volume to the water absorption and rheological behaviour in a model waterborne coating

Waterborne coatings are a viable alternative to traditional solventborne coatings to reduce the emissions of harmful Volatile Organic Compounds. Currently, their development is hindered by the complex structure created in the film. This structure arises when the coating goes from a heterogeneous liquid dispersion to a solid film. In particular, the focus of this research is to understand how the film’s structure is related to the water transport for the purpose of improving the film’s anticorrosion performance.
Most films are treated as homogenized after drying, with some reports of heterogeneous areas located at the particle boundaries leading to preferential water absorption pathway. Nevertheless, these heterogeneities and their effect on have not been thoroughly studied. Small angle scattering experiments would be used to prove that there is a surfactant-rich area at the inter-particle boundary, as well as that this surfactant-rich area is responsible for faster water uptake in the films. Finally, varying the surfactant concentration will prove that a micellar-like order is created at higher surfactant concentrations, reducing the size of the surfactant-rich area.