Spin‐spray‐assisted layer‐by‐layer assembly of thick polymer films with self‐healing, UV‐protection, and anti‐fog properties

Abstract Layer‐by‐layer (LbL) deposition of oppositely charged polyelectrolytes has been widely used to make responsive and multifunctional smart films. Herein, a high‐performance and multifunctional LbL film was fabricated by using a spin‐spray‐assisted (SSA‐LbL) assembly method with poly(diallyldimethylammonium chloride) (PDDA) and poly(acrylic acid) (PAA). The SSA‐LbL method was found to be more efficient and time‐saver in making a homogeneous thick film in tens of micrometers, compared to the conventional immersive assembly method which makes thin films in the nanometer range. When scratches occur, the film shows a quick and durable self‐healing capability due to the dynamic movement of the flexible polyelectrolyte complex chains at the edges of the scratches. An effective UV‐block performance was incorporated into the film by using the graphene oxide (GO) and titanium dioxide (TiO 2 ) nanoparticles as UV‐blocking additives. Due to the hydrophilic feature of PDDA/PAA molecules, the film also showed the anti‐fog property in different environmental conditions. The effect of the concentration of GO and TiO 2 nanoparticles on self‐healing and UV‐protection properties were investigated. Also, the optimum range of concentration of GO and TiO 2 nanoparticles in polyelectrolyte solutions was determined to fabricate the film with the combined features of self‐healable, UV‐blocking, and anti‐fog.