Anionically Stabilized Cellulose Nanofibrils through Succinylation Pretreatment in Urea-Lithium Chloride Deep...

Area of Science:

• Green Chemistry
• Materials Science
• Polymer Chemistry

Background:

• Deep eutectic solvents (DESs) are emerging as environmentally friendly alternatives to traditional organic solvents.
• Cellulose functionalization is crucial for developing advanced materials with tailored properties.
• Traditional methods often involve harsh chemicals and conditions, posing environmental concerns.

Purpose of the Study:

• To investigate the efficacy of urea-LiCl DES as a reaction medium for the anionic functionalization of wood cellulose.
• To optimize reaction conditions (temperature and time) for maximizing carboxyl content and yield.
• To characterize the resulting cellulose nanomaterials and assess the solvent's impact on cellulose integrity.

Main Methods:

• Anionic functionalization of wood cellulose using succinic anhydride in urea-LiCl DES.
• Evaluation of reaction parameters including temperature and time.
• Analysis of carboxyl content, yield, degree of polymerization, and crystallinity.
• Nanofibrillation of functionalized cellulose using a microfluidizer.
• Characterization of nanomaterials using atomic force microscopy (AFM).

Main Results:

• Urea-LiCl DES served as a nondegrading and nondissolving medium for cellulose functionalization.
• Optimal conditions (70-80°C for 2 hours) yielded highly viscous, transparent cellulose gels with high carboxyl content.
• Nanofibrillation produced cellulose nanomaterials with diameters of 2-7 nm.
• Higher temperatures (90°C) led to larger nanoparticles and aggregates but improved thermal stability.

Conclusions:

• Urea-LiCl DES is a viable and green reaction medium for cellulose anionic functionalization.
• Controlled reaction conditions enable the production of functionalized cellulose nanomaterials with tunable properties.
• The developed method offers a promising route for creating advanced cellulose-based materials for various applications.