Modification and characterization of a novel and fluorine-free cellulose nanofiber with hydrophobic and oleophobic properties

Structure-property relationships in shellac-coated paper: impact of coating parameters on high-barrier bio-based packaging applications

Paper coated with bio-based materials has attracted significant interest as an alternative to plastic-based materials for food packaging, with poor moisture barrier of coated paper posing a challenge to broader applications. Shellac is a promising biopolymer because of its low cost, biodegradability, and wide approval as a food additive and food contact material. In this work, we have systematically studied the role of shellac concentration in butanol and the number of coatings on coated paper's moisture and oil barrier properties. We investigated surface, physicochemical, and thermal properties of coated paper to elucidate specific interactions between shellac and paper substrate and characterize coating morphology, and their effect on barrier properties of coated paper. We found that every layer of coating resulted in an improvement in surface properties, with porosity decreasing by 90 % and surface roughness decreasing by 80 % in a single coat of 15 % (w/w) shellac solution. A low concentration of shellac (7.5 % (w/w)) was found to be less effective in improving barrier properties compared to the highest shellac concentration of 15 % (w/w) used in our study, but still caused a significant increase in the GSM (change in coated weight (g.m-2)). Four coatings of the 15 % (w/w) shellac solution resulted in a water vapor transmittance rate (WVTR) of 56 g m-2 day-1, a water barrier (COBB 180) of 1 g m-2, and an oil barrier (KIT) of 12. These results meet the strictest requirements for very high-barrier packaging applications.

Food packaging solutions in the post-per- and polyfluoroalkyl substances (PFAS) and microplastics era: A review of functions, materials, and bio-based alternatives

Food packaging (FP) is essential for preserving food quality, safety, and extending shelf-life. However, growing concerns about the environmental and health impacts of conventional packaging materials, particularly per- and polyfluoroalkyl substances (PFAS) and microplastics, are driving a major transformation in FP design. PFAS, synthetic compounds with dual hydro- and lipophobicity, have been widely employed in food packaging materials (FPMs) to impart desirable water and grease repellency. However, PFAS bioaccumulate in the human body and have been linked to multiple health effects, including immune system dysfunction, cancer, and developmental problems. The detection of microplastics in various FPMs has raised significant concerns regarding their potential migration into food and subsequent ingestion. This comprehensive review examines the current landscape of FPMs, their functions, and physicochemical properties to put into perspective why there is widespread use of PFAS and microplastics in FPMs. The review then addresses the challenges posed by PFAS and microplastics, emphasizing the urgent need for sustainable and bio-based alternatives. We highlight promising advancements in sustainable and renewable materials, including plant-derived polysaccharides, proteins, and waxes, as well as recycled and upcycled materials. The integration of these sustainable materials into active packaging systems is also examined, indicating innovations in oxygen scavengers, moisture absorbers, and antimicrobial packaging. The review concludes by identifying key research gaps and future directions, including the need for comprehensive life cycle assessments and strategies to improve scalability and cost-effectiveness. As the FP industry evolves, a holistic approach considering environmental impact, functionality, and consumer acceptance will be crucial in developing truly sustainable packaging solutions.