A Green Cellulose Dissolution System for Producing Tunable Regenerated Nanocellulose Formate

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Cellulose dissolution is crucial for producing advanced materials.
• Traditional methods often involve harsh chemicals or high temperatures.
• Developing efficient and sustainable cellulose processing is a key challenge.

Purpose of the Study:

• To develop a novel, cost-effective, and sustainable method for cellulose dissolution.
• To enable the controllable production of regenerated nanocellulose formate (RNCF) with tunable properties.
• To explore the versatile applications of RNCF, including Pickering emulsions.

Main Methods:

• Cellulose preimpregnation at room temperature using LiBr·3H₂O.
• Dissolution of preimpregnated cellulose in formic acid (FA).
• Characterization using XPS, NMR, and hydrogen-deuterium exchange to elucidate mechanisms.

Main Results:

• Achieved high cellulose solubility (up to 10 wt %) and efficient dissolution of cotton pulp.
• Successfully produced regenerated nanocellulose formate (RNCF) with 100% yield, high DS (>1.2), and tunable DP (300-700).
• Demonstrated RNCF's ability to form filaments, films, hydrogels, and aerogels, and stabilize Pickering emulsions.

Conclusions:

• The LiBr·3H₂O preimpregnation significantly enhances cellulose accessibility by disrupting hydrogen bonds and crystalline structure.
• This ambient, sustainable, and cost-effective method promotes efficient cellulose dissolution and RNCF production.
• The developed RNCF offers a versatile platform for advanced cellulose-based functional materials.