Thermo-Responsive Cellulose-Based Material with Switchable Wettability for Controllable Oil/Water Separation

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Cellulose-based materials offer sustainable platforms for advanced applications.
• Thermo-responsive polymers can alter properties with temperature changes.
• Developing efficient oil/water separation methods is crucial for environmental remediation.

Purpose of the Study:

• To synthesize a thermo-responsive cellulose-graft-poly(N-isopropylacrylamide) (cellulose-g-PNIPAAm) material.
• To investigate the temperature-dependent wettability transition of the material.
• To evaluate the material's performance in switchable oil/water separation.

Main Methods:

• Grafting N-isopropylacrylamide (NIPAAm) onto bagasse pulp cellulose using Ce(IV)-initiated free radical polymerization.
• Characterization of wettability using water contact angle (WCA) measurements at different temperatures.
• Analysis of the thermo-responsive mechanism via in situ variable-temperature 13C NMR, 1H NMR, and AFM.

Main Results:

• The cellulose-g-PNIPAAm paper exhibited a rapid wettability switch from hydrophilic (0° at 25 °C) to hydrophobic (134.2° at 45 °C).
• The material demonstrated effective switchable separation of oil/water mixtures, allowing water passage below 45 °C and oil passage above 45 °C.
• The paper maintained its switchable wettability and separation performance over five regeneration cycles.

Conclusions:

• A novel thermo-responsive cellulose-based material with tunable wettability was successfully prepared.
• The material shows significant potential for applications in smart oil/water separation technologies.
• The developed material offers a sustainable and recyclable solution for liquid mixture separation.