Janus hybrid sustainable all-cellulose nanofiber sponge for oil-water separation

• Published in: International journal of biological macromolecules Vol. 185; pp. 997 - 1004
• Main Authors: Agaba, Aphra, Marriam, Ifra, Tebyetekerwa, Mike, Yuanhao, Wang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31-08-2021
• Subjects: Cellulose nanofibers sponge; Janus; Oil-water separation; Oil-water separation; Janus; Cellulose nanofibers sponge
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2021.07.027

Two-faced characteristics and performance of materials driven by asymmetric physical or chemical properties exist in Janus hybrid materials which show synergistic and improved properties for a variety of applications. Here, we report a facile synthesis of Janus hybrid sustainable cellulose nanofibers (CNFs) sponge with asymmetric wettability and strong mechanical property for excellent separation efficiency of oil-water emulsions. Briefly, the CNF Janus hybrid sponge was fabricated by freeze-drying of two separate CNF suspensions into one, each prepared separately by introducing CNFs in methyltrimethoxysilane (MTMS) or 3-glycidoxypropyltrimethoxysilane (GPTMS) for hydrophobic or hydrophilic performance, respectively. The sponge demonstrated satisfactory mechanical stability with an excellent recovery from 80% compressive strain and high pore tortuosity. When employed for oil-water separation, the Janus hybrid sponge could selectively be used to collect water or oil by just switching its side facing the oil-water mixture feed via unidirectional gravity-assisted separation, with recyclability. The fabrication of such Janus hybrid sponge is one of the many approaches for utilizing nanofibers in structurally adaptive, self-supported asymmetric membrane structures in a 3D network.
•A Janus hybrid sustainable all-cellulose nanofibers (CNF) sponge was fabricated.•The sponge had opposing surface wettability and strong mechanical property.•The sponge was applied in oil-water separation with re-usability.