Electrochemical impedance spectroscopy study of waterborne coatings film formation

Influence of coalescing aids on the latex properties and film formation of waterborne coatings

“…EIS is an established method for the evaluation of the corrosion protection of coatings but can also be used to assess film properties in general . The measurements of the impedance spectra and data analysis were performed with the same procedures as described in our previous article, where we demonstrated that EIS can be used to observe the progress of latex film formation. The data were analyzed with an equivalent circuit model consisting of a capacitor representing the barrier properties of the coating connected in parallel with an infinite Warburg element, which describes the extent of ion diffusion through the coating [Figure (a)] .…”

“…In light of previous research, where the extent of Warburg diffusion has been directly related to particle coalescence, the analysis of EIS results was focused on the product between the Warburg coefficient (σ c ) and the film thickness ( d c ), which is a representation of the extent of Warburg diffusion. Multiplication with d c is used to compensate for thickness variation between samples.…”

“…During an EIS experiment, water and ions from the test electrolyte (in our case, 0.1 M NaCl) penetrate into the polymer film, and according to Skale et al ., the square root of the ion diffusivity in the polymer matrix is proportional to σ c . As latex particles coalesce, the diffusion of ions is hindered, and the value of σ c drops …”

“…In this study, we extended a recently developed electrochemical impedance spectroscopy (EIS) based method for studying film formation to evaluate how different amounts of hydrophilic and hydrophobic coalescing aids affected the dynamics and quality of latex film formation. To thoroughly investigate the interactions between the coalescing aids and latex binders, the dispersion stability, application properties, and drying profiles were determined.…”

Electrochemical impedance spectroscopy as a tool to measure cathodic disbondment on coated steel surfaces: Capabilities and limitations

“…Electrochemical impedance spectroscopy (EIS) is a technique that has been used for decades to measure and monitor the degradation of organic coatings by quantitatively measuring the resistances and capacitances of coated electrodes in an electrochemical cell [14][15][16][17][18][19][20]. The Nyquist plots of coated metals have characteristic behavior dependent on the state of the coating, thereby making it possible to follow the penetration of an electrolyte into the coating and to detect the initiation of corrosion at the metal/coating interface [21].…”