Simple and environmentally friendly preparation of cellulose hydrogels using an ionic liquid

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Cellulose hydrogels are versatile biomaterials with applications in drug delivery, tissue engineering, and absorbent materials.
• Traditional cellulose hydrogel production often involves harsh chemicals, crosslinking agents, and energy-intensive processes, limiting their environmental sustainability and scalability.

Purpose of the Study:

• To develop a facile, environmentally benign, and scalable method for producing cellulose hydrogels.
• To investigate the influence of cellulose concentration on hydrogel properties using a novel ionic liquid/DMSO solvent system.
• To establish a recyclable system for the ionic liquid solvent used in cellulose dissolution.

Main Methods:

• Complete dissolution of cellulose (6–20 wt%) in an [BMIm][OAc]/DMSO mixed solution at room temperature and ambient pressure.
• Solvent replacement method by immersing cellulose solution in deionized water to form hydrogels without crosslinking agents.
• Development of a system for recovering and reusing approximately 80% of the ionic liquid.

Main Results:

• Cellulose hydrogels were successfully produced across a wide concentration range.
• The ionic liquid solvent system demonstrated excellent recyclability, minimizing environmental impact.
• Hydrogel properties such as pore size, water content, and mechanical strength were tunable based on cellulose concentration.
• Crystallinity and thermal stability of the hydrogels were independent of the initial cellulose concentration.

Conclusions:

• The developed [BMIm][OAc]/DMSO mixed solution offers an efficient and sustainable route for cellulose hydrogel fabrication.
• The solvent replacement technique provides a crosslinking-free method for hydrogel formation.
• The recyclability of the ionic liquid and the tunable nature of the hydrogel properties highlight the potential for industrial applications.