Superior mechanical properties of hybrid organic-inorganic superhydrophilic thin film on plastic substrate

Abstract

A superior mechanical properties of bilayer thin film with anti-fogging performance for polyethylene terephthalate (PET) substrate was developed. The bottom layer, acting as a mechanical support, is a hybrid organic-inorganic thin film with interpenetrating network. Atop this layer, the superhydrophilic nanoparticles were fabricated and deposited by spray-coating to yield a layer exhibiting the superhydrophilic and anti-fogging effect. Contact angles of water were measured to examine the hydrophilicity of the hybrid organic-inorganic superhydrophilic thin film. Besides, UV/VIS spectrophotometer, atomic force microscopy (AFM) and scanning electron microscope (SEM) were carried out to characterize the optical properties and film structure of the thin film. For the actual application, variety of industrial tests such as pencil test (ASTM D 3363 standard), adhesion test (ISO 2409 standard) and steam test, were employed to evaluate the prepared hybrid organic-inorganic superhydrophilic thin film. Especially, the addition of the bottom layer results in an improvement of the adhesion between the superhydrophilic nanoparticles and PET substrate. The experimental results exhibited that the mechanical, optical, superhydrophilic and anti-fogging properties were effectively improved after applying the hybrid organic-inorganic superhydrophilic thin film on PET substrate.