Production of Nanocellulose Using Hydrated Deep Eutectic Solvent Combined with Ultrasonic Treatment

Area of Science:

• Materials Science
• Chemical Engineering
• Biotechnology

Background:

• Nanocellulose production requires efficient pretreatment methods for commercial viability.
• Current methods often face challenges in scalability and cost-effectiveness.
• Deep eutectic solvents (DES) offer potential as environmentally friendly alternatives.

Purpose of the Study:

• To develop a novel, scalable method for nanocellulose production.
• To investigate the use of a hydrated choline chloride/oxalic acid dihydrate DES combined with ultrasonication.
• To assess the impact of water on DES properties for pulp dissociation.

Main Methods:

• Utilized a hydrated choline chloride/oxalic acid dihydrate deep eutectic solvent (DES).
• Employed an 800 W ultrasonic treatment for pulp dissociation.
• Characterized solvent properties using Kamlet-Taft solvatochromic parameters.
• Processed kraft pulp at 80 °C for 1 hour.

Main Results:

• The hydrated DES maintained favorable solvation properties despite significant water content.
• Water addition facilitated ion ionization and delocalization, enhancing solvent characteristics.
• One-step treatment of kraft pulp in the hydrated DES with ultrasonication yielded nanocellulose.
• Successfully produced cellulose nanofibers and cellulose nanocrystals.

Conclusions:

• The hydrated DES-ultrasonication approach is effective for kraft pulp pretreatment.
• This method offers a viable alternative for large-scale nanocellulose production.
• The enhanced solvent properties due to water are crucial for efficient nanocellulose yield.