Electrical behaviour of native cellulose nanofibril/carbon nanotube hybrid aerogels under cyclic compression.

Miao Wang,Olli Ikkala,Nonappa Nonappa,Ilya V Anoshkin,Robin H A Ras,Albert G Nasibulin,Esko I Kauppinen,Janne Laine

doi:10.1039/c6ra16202a

Abstract

Hybrid aerogels consisting of cellulose nanofibers (CNF) and modified few-walled carbon nanotubes (FWCNT) are investigated under cyclic mechanical compression to explore "electrical fatigue". For this purpose the FWCNTs were hydrophilized, thus promoting their aqueous dispersibility to allow FWCNT/CNF hybrid hydrogels, followed by freeze-drying to obtain hybrid aerogels. The optimized composition consisting of FWCNT/CNF 20/80 wt/wt showed conductivity of 10-5 S cm-1 as promoted due to double percolation, and showed only small changes in electrical and mechanical behaviour upon cycling 100 times. The electrical behaviour under cycled compression shows good stability and reversibility.

Highlights

Porous and lightweight native nanocellulose aerogels or sponge-like materials have aroused extensive interest.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33] Unlike classic aerogels based on silica, which are relatively brittle, they can allow reduced brittleness and even exibility, combining very low densities and high porosities.[2,3,4,7,34,35] Cellulose nano brils (CNF), known as nano brillar cellulose (NFC) or micro brillated cellulose (MFC), are attractive due to the enhanced mechanical properties of native cellulose crystals with a modulus of ca. 140 GPa,[36] and the fact that cellulose is a sustainable and the most abundant polymer on Earth as it is available from plant cell walls.[37]
Hybrid aerogels consisting of cellulose nanofibers (CNF) and modified few-walled carbon nanotubes (FWCNT) are investigated under cyclic mechanical compression to explore “electrical fatigue”
Most emphasis will subsequently be given to the composition FWCNT/CNF 20/80 wt/wt, as this composition will turn most promising under repeated cycles, as will be discussed later

Summary

Introduction

Porous and lightweight native nanocellulose aerogels or sponge-like materials have aroused extensive interest.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33] Unlike classic aerogels based on silica, which are relatively brittle, they can allow reduced brittleness and even exibility, combining very low densities and high porosities.[2,3,4,7,34,35] Cellulose nano brils (CNF), known as nano brillar cellulose (NFC) or micro brillated cellulose (MFC), are attractive due to the enhanced mechanical properties of native cellulose crystals with a modulus of ca. 140 GPa,[36] and the fact that cellulose is a sustainable and the most abundant polymer on Earth as it is available from plant cell walls.[37]. Miao; Anoshkin, Ilya V.; Nasibulin, Albert G.; Ras, Robin H A; Nonappa, Nonappa; Laine, Janne; Kauppinen, Esko I.; Ikkala, Olli Electrical behaviour of native cellulose nanofibril/carbon nanotube hybrid aerogels under cyclic compression Electrical behaviour of native cellulose nanofibril/carbon nanotube hybrid aerogels under cyclic compression.

Results

Conclusion