Innovative green synthesis of hydrophobic covalent networks using ethyl cellulose/thymol eutectic systems†

Cellulose and its derivatives have shown significant potential as plastic replacement materials due to their outstanding properties. However, current research still faces challenges related to green synthesis, structural design, and multifunctionality. To address these issues, an innovative green eutectic solvent (ES) based on ethylcellulose (EC) and thymol (Thy) is proposed for the preparation of high-performance cellulose-based hydrophobic covalently crosslinked networks. EC and Thy can be prepared as a molecular solvent system in one step without the need for external solvents. Subsequently, co-monomers and chemically stable lithium salts are introduced into the homogeneous EC/Thy ES medium, resulting in the formation of highly transparent, mechanically tough, and ionically conductive cellulosic polymer films (CPFs) through in situ photopolymerization. Furthermore, the prepolymer achieves a precise replication of the complex microstructure of the natural rose surface with the help of stearic acid, imparting superhydrophobicity to the CPF. The prepared superhydrophobic CPF exhibits excellent self-cleaning ability, pressure responsiveness, and stable sensing performance under different humidity environments. The biomass-based eutectic strategy demonstrated in this paper presents a green and efficient method for preparing multifunctional cellulose-based materials with a wide range of applications.