Long-lasting intrinsic polyethylene antifogging films generated by incorporating SiO2 nanoparticles into covalently grafted antifog agents

Abstract

Antifogging films are used in an increasing number of applications in greenhouse cultivation because fog formation affects transmission. Here, we summarize a way to improve the antifogging duration of linear low-density polyethylene (LLDPE) films by controlling the migration of the antifog agent. We prepared SiO2-grafted glycerin monostearate (SiO2-g-GMS) by covalently grafting surface modified SiO2 nanoparticles and glycerin acrylic acid monostearate (GMS-AA). Then, SiO2-g-GMS was added in LLDPE, and antifogging films were prepared for study of their properties. The reaction with modified SiO2 and GMS-AA was demonstrated by Fourier transform infrared spectroscopy, thermogravimetric analysis and grafting degree (GD). The GD of SiO2-g-GMS was approximately 54.95%. Accelerating dripping experiments and contact angle measurements illustrated that GMS-AA-grafted modified SiO2 exhibited delayed migration of the antifog agent, prolonging the antifogging duration by approximately 3 days. We determined that 3 wt% SiO2-g-GMS was a suitable proportion, considering economy and the desired properties. The SEM images indicate that dispersion of SiO2-g-GMS in the film was extensive, and the particle size was 160 ± 40 nm. In addition, the study also showed how modified SiO2 grafted with GMS-AA does not affect the processes and usability of antifogging films.