Stabilization of Pickering emulsions with cellulose nanofibers derived from oil palm fruit bunch

Abstract

Converting oil palm empty fruit bunch (OPEFB) to high value-added products can contribute to sustainable development by decreasing solid waste. In this paper, cellulose nanofibers (CNFs) were prepared from OPEFB by following the processes of soda pulping, bleaching, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation, and high-pressure homogenization. Subsequently, the as-prepared CNFs were studied for their potential to stabilize Pickering emulsions. TEM results showed that the as-prepared individual CNFs were 4 nm in width and a few microns in length. Stable Pickering emulsions occurred at 2% CNF dosage, with emulsion droplet of 10 μm in terms of volume mean diameter, D [4, 3]. SEM results supported the presence of CNFs at the O/W interfaces, and CNF networks between the emulsion droplets. The effect of salt concentrations on the emulsion performance was further studied, showing that the conversion of emulsions to gels occurs at a salt concentration of 50 mM or higher.