Preparation of a superhydrophilic SiO2 nanoparticles coated chitosan-sodium phytate film by a simple ethanol soaking process.

The development of environmentally friendly and transparent superhydrophilic food packaging materials is essential in our daily lives. The objective of this study was to develop a simple method of preparing a superhydrophilic, transparent, and biodegradable composite film. The composite film was obtained by soaking a chitosan-sodium phytate film in an ethanol solution of SiO 2 nanoparticles. The results showed that when the chitosan-sodium phytate film was coated with SiO 2 nanoparticles that were dissolved in 75% ethanol, its water contact angle (WCA) was reduced from 100° to 3°, and the film surface was changed from a hydrophobic to a superhydrophilic. Furthermore, the oxygen transmission rate (OTR) was significantly reduced, and the mechanical properties of the film were improved. The method is easy to carry out and can be used for the potential production of superhydrophilic materials. • A superhydrophilic chitosan film was prepared by an ethanol soaking process. • When ethanol concentration was 75%, the contact angle of the chitosan film was 3°. • The obtained film showed excellent water vapor and oxygen barrier properties. [ABSTRACT FROM AUTHOR]