Functionalization of Cellulosic Derivatives for Sustainable Packaging and Wastewater Purification

The urgent need to reduce the use of fossil-based plastics has encouraged the development of new bio-based and biodegradable materials. This PhD project focuses on the valorisation of cellulose, the most abundant biopolymer on Earth, through chemical functionalization in mild aqueous conditions. The work relates to the principles of the circular economy, the European Green Deal and the Italian NRRP, aiming to design innovative and sustainable solutions in two fields with high environmental impact: packaging and wastewater treatment. In the first part, cellulose derivatives such as carboxymethylcellulose (CMC) and TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl-oxidized) nanofibers (TEMPO-CNF) were chemically modified to prepare films and coatings with improved barrier and mechanical properties. These materials were tested for their resistance to water, oil and gases, in order to replace conventional plastics and to preserve the recyclability of paper-based supports. The results show that amidation and crosslinking strategies can enhance hydrophobicity and stability, while maintaining biodegradability, offering a valid alternative to fossil-based polymers in sustainable packaging. In the second part, the research developed innovative adsorbent materials for water purification. TEMPO-CNF was surface-functionalized with aromatic amines to increase hydrophobicity and introduce specific interactions with organic pollutants. The modified nanofibers demonstrated high adsorption capacity against model contaminants such as dyes and pharmaceuticals, good reusability and biodegradability, proving their potential as advanced bio-based adsorbents. Overall, this doctoral work demonstrates how cellulose derivatives can be transformed into functional, eco-friendly materials that answer global challenges related to plastic pollution and water scarcity. By combining material chemistry with sustainability goals, the research contributes to the design of next-generation biopolymers able to support ecological transition and resource efficiency.