title: Multiwalled Carbon Nanotube/Cellulose Composite: From Aqueous Dispersions to Pickering Emulsions.
abstract: A mild and simple way to prepare stable aqueous colloidal suspensions of composite particles made of a cellulosic material (Sigmacell cellulose) and multiwalled carbon nanotubes (MWCNTs) is reported. These suspensions can be dried and redispersed in water at pH 10.5. Starting with rather crude initial materials, commercial Sigmacell cellulose and MWCNTs, a significant fraction of composite dispersed in water could be obtained. The solid composites and their colloidal suspensions were characterized by electronic microscopy, thermal analyses, FTIR and Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and light scattering. The composite particles consist of tenuous aggregates of CNTs and cellulose, several hundred nanometers large, and are composed of 55 wt % cellulose and 45 wt % CNTs. Such particles were shown to stabilize cyclohexane-in-water emulsions. The adsorption and the elasticity of the layer they form at interface were characterized by the pendant drop method. The stability of the oil-in-water emulsions was attributed to the formation of an elastic network of composite particles at interface. Cyclohexane droplet diameters could be tuned from 20 to 100 μm by adjusting the concentration of composite particles. This behavior was attributed to the limited coalescence phenomenon, just as expected for Pickering emulsions. Interestingly, cyclohexane droplets were stable over time and sustained pH modifications over a wide range, although acidic pH induced accelerated creaming. This study points out the possibility of combining crude cellulose and MWCNTs through a simple process to obtain colloidal systems of interest for the design of functional conductive materials.
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR 5253, CNRS-ENSCM-UM, Université de Montpellier, CC 1701, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: Carlos
authors.initials: C
authors.lastname: Avendano
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR 5253, CNRS-ENSCM-UM, Université de Montpellier, CC 1701, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Brun
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR 5253, CNRS-ENSCM-UM, Université de Montpellier, CC 1701, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Fontaine
authors.affiliation: Laboratoire Charles Coulomb, UMR 5221, CNRS-UM, Université de Montpellier, CC069, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: Martin
authors.initials: M
authors.lastname: In
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR 5253, CNRS-ENSCM-UM, Université de Montpellier, CC 1701, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Mehdi
authors.affiliation: Laboratoire Charles Coulomb, UMR 5221, CNRS-UM, Université de Montpellier, CC069, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: Antonio
authors.initials: A
authors.lastname: Stocco
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR 5253, CNRS-ENSCM-UM, Université de Montpellier, CC 1701, Place Eugène Bataillon, 34095 Montpellier, France.
authors.forename: André
authors.initials: A
authors.lastname: Vioux