Surface modification of PVA thin film by nonthermal atmospheric pressure plasma for antifogging property

In this work, a polyvinyl alcohol (PVA) thin film was modified by exposure to a dielectric barrier discharge argon plasma. The plasma was generated by a sinusoidal power supply with discharge voltage of 4.75 kV (rms), and frequency of 30 kHz at duty cycle 6.13%. The effect of the plasma on the PVA thin film was investigated by analyzing the contact angle, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and UV–visible spectroscopy. After the plasma treatment, the contact angle was found to be decrease from 29.6 ± 0.4° to 14.5 ± 0.2°, which implied that the surface property had changed to a hydrophilic state caused by an increase in the surface roughness and introduction of oxygen, including a polar carbonyl group. It was found that the plasma-treated hydrophilic PVA thin film exhibited excellent antifogging and highly transparent characteristics, making it an appropriate material for food packaging and green houses.