Nonsolvent-Induced Phase Separation-Jet Spinning: An Innovative Technique for Producing Cellulosic Nanofilms,...

Area of Science:

• Materials Science
• Polymer Science
• Chemical Engineering

Background:

• Developing straightforward methods for biobased porous materials is challenging.
• Nonsolvent-induced phase separation (NIPS) is a common technique for polymer processing.
• Existing methods often require organic solvents and chemical cross-linkers.

Purpose of the Study:

• To introduce and validate a novel fabrication technique, nonsolvent-induced phase separation-jet spinning (NIPS-JS), for cellulose acetate nanofilms.
• To demonstrate the application of NIPS-JS fabricated films in creating ultralight cellulosic sponges.
• To develop a scalable and cost-effective method for producing advanced porous materials.

Main Methods:

• Utilized nonsolvent-induced phase separation coupled with high-velocity coaxial jets (NIPS-JS) for rapid nanofilm formation.
• Employed cryo-templating and lyophilization to construct three-dimensional cellulosic sponges from the nanofilms.
• Investigated the effect of ethanol addition on cryo-templating reproducibility and sponge shrinkage.

Main Results:

• Achieved rapid formation of cellulose acetate nanofilms (40-50 nm thickness) with high production rates (>0.8 g·min⁻¹).
• Fabricated ultralight cellulosic sponges with ultralow density (5-10 kg·m⁻³) and high porosity (>99%) without chemical cross-linkers.
• Demonstrated enhanced reproducibility and minimized shrinkage in cryo-templating with 0.2-1 wt % ethanol addition.

Conclusions:

• NIPS-JS is an efficient and tunable technique for processing diverse polymeric materials.
• The developed method offers a sustainable pathway for producing advanced, ultralight porous materials.
• This approach reduces reliance on organic solvents and chemical cross-linkers in porous material fabrication.