Modification and characterization of a novel and fluorine-free nanocellulose material with hydrophobic and oleophobic properties.

Abstract

Abstract In this study, a brand-new, easy, and environmentally friendly approach for chemically functionalizing 2,2,6,6-tetramethylpiperidinyloxyl radical (TEMPO)-oxidized cellulose nanofibers (TOCNFs) to produce modified cellulose nanofibers (octadecylamine (ODA)-citric acid (CA)-CNFs) was proposed. The effects of the ODA/TOCNF mass ratio on the chemical structure, morphology, surface hydrophobicity and oleophobicity were studied. According to Fourier transform infrared spectroscopy (FTIR) analysis, ODA was successfully grafted onto the TOCNFs by simple CA esterification and amidation reactions. The water contact angle (WCA) of the ODA-CA-CNFs reached 139.6°, and the castor oil contact angle (OCA) reached 130.6°. Scanning electron microscopy (SEM) showed that a new rough structure was formed on the ODA-CA-CNF surface. Thus, the strategy chosen herein is recognized as being ecologically benign for the mass production of modified CNFs without the use of hazardous chemicals. The ODA-CA-CNFs with excellent water/oil-resistance properties and fluorine-free properties can replace petrochemical materials and can be used in the fields of fluorine-free oil-proof paper, food packaging paper, packaging materials and so on, which is of great significance to human health and environmental protection.