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 (TiO2) 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 TiO2 nanoparticles on self-healing and UV-protection properties were investigated. Also, the optimum range of concentration of GO and TiO2 nanoparticles in polyelectrolyte solutions was determined to fabricate the film with the combined features of self-healable, UV-blocking, and anti-fog.
