Structural Description of the Interface of Pickering Emulsions Stabilized by Cellulose Nanocrystals

Abstract

The cotton cellulose nanocrystals (CNCs) used in this study are rod-like particles with dimensions in the nanoscale (195 nm long, 23 nm width and 6 nm thick) able to stabilize Pickering emulsions. The adsorption of CNCs at an oil-water interface has been investigated by small angle neutron scattering (SANS) with and without surface charge, and varying CNC concentration from 2 to 5 g/L. Average thicknesses of the interfacial CNC layer around the emulsion droplets of 7 and 18 nm were determined for charged and uncharged CNC, respectively, regardless of their concentration in suspension. This suggests that CNC particles lie as a monolayer varying in surface density. Using several phase contrast variations, the neutron wave vector (Q) dependence with the intensity showed that CNCs are in contact with the oil phase only via the surface of the CNC and not immersed in oil since the Porod behavior is observed over the whole Q-range revealing no deformation of the oil surface at a nanometer scale. This result promotes the postulate that the (2 0 0) crystalline plane of the CNC directly interacts with the interface.

Nanocellulose-assisted dispersion of graphene to fabricate poly(vinyl alcohol)/graphene nanocomposite for humidity sensing

“…All above conforms that completely individualized NFC could act as a dispersing agent for reduced rGO sheets. Molecular dynamics calculations have shown that there is a special surface of cellulose nanocrystal, in which CeH moieties are predominant to display hydrophobic character [48]. Hence, the hydrophobic interaction between the specific crystalline faces of NFC and the rGO sheets is expected.…”

Research on cellulose nanocrystals produced from cellulose sources with various polymorphs

“…As a nano-material, CNCs exhibits many appealing properties, such as high crystallinity, large aspect ratio, biodegradability, nano-dimensions, light weight, and large surface area. [11][12][13] Owing to these features, it has shown great promise in many elds, including reinforcing llers for composite materials, 14 stabilizing agents for emulsions, 15 templates for the chemical synthesis of inorganic materials, 16 and so on. The studies on CNCs have gained increasing attention in recent years.…”

A dry and fully dispersible bacterial cellulose formulation as a stabilizer for oil-in-water emulsions

“…BC's long but thin fibres, thus more flexible, can easily bend and shape to the interface. Several works have also shown the arrangement of cellulose fibres at the interface, covering the dispersed oil droplets (Cherhal et al, 2016;Kalashnikova et al, 2012;Ougiya et al, 1997;Winuprasith & Suphantharika, 2015). However, only Winuprasith and Suphantharika (2015) mentioned the three-dimensional networks formed by fibres in the continuous aqueous phase and how they play a structural supporting role for the emulsion droplets.…”