One-step Coassembled Nanocoatings on Paper for Potential Packaging Applications
Sonia E. Chavez, Hao Ding, Brandon L. Williams, Sunghyun Nam, Zaili Hou, Dongqiao Zhang, Luyi Sun
Abstract
Plastics films have been widely used in food packaging. But due to the environmental concerns of plastics films, there is a trend of replacing plastics films with paper for food packaging. To meet the requirements of packaging, the paper must be modified to improve its barrier properties. In this report, a sonication and dip coating method was developed to deposit a polyvinyl alcohol (PVA)/montmorillonite (MMT) nanocoating on two representative paper substrates: regular paper and cotton paper. The coated paper substrates were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), water vapor transmission rate (WVTR), and microscale combustion calorimetry (MCC). The XRD results support the formation of well-aligned MMT nanosheets on paper substrates, and the SEM images show that most pores on the substrates were covered by the nanocoatings, which leads to a drastic decrease in WVTR of the coated substrates. The nanocoatings also led to a minor improvement in flame retardancy. The results suggest that applying nanocoating is a promising approach to improving the barrier properties of paper for potential packaging applications.