ABSTRACT Liquid‐assisted atmospheric plasma polymerisation (LA‐APP) enables the rapid curing of liquid monomer layers into polymer thin films without chemical initiators. This study investigates the plasma‐induced free‐radical polymerisation of trimethylolpropane propoxylate triacrylate (TMPTA‐PO) to elucidate the role of liquid monomer layer thickness and plasma exposure on curing efficiency. Static and dynamic deposition approaches revealed a thickness‐dependent diffusion depth of plasma‐generated reactive species, with FTIR spectroscopy quantifying a high conversion degree for thin layers and incomplete bulk curing for thicker layers. The approach was implemented to embed rosmarinic acid as a natural antioxidant, yielding thin films with preserved antioxidant activity. These findings provide fundamental insight into plasma–liquid interactions and guidelines for controlled fabrication of multifunctional coatings.
Lanza et al. (Mon,) studied this question.