Cellulose Nanocrystal and Water-Soluble Cellulose Derivative Based Electromechanical Bending Actuators.

Daniela M Correia,Senentxu Lanceros-Méndez,Rafaela M Meira,Mikel Rincón-Iglesias,Erlantz Lizundia

doi:10.3390/ma13102294

Abstract

This study reports a versatile method for the development of cellulose nanocrystals (CNCs) and water-soluble cellulose derivatives (methyl cellulose (MC), hydroxypropyl cellulose (HPC), and sodium carboxymethyl cellulose (NaCMC)) films comprising the ionic liquid (IL) 2-hydroxy-ethyl-trimethylammonium dihydrogen phosphate ([Ch][DHP]) for actuator fabrication. The influence of the IL content on the morphology and physico–chemical properties of free-standing composite films was evaluated. Independently of the cellulose derivative, the ductility of the films increases upon [Ch][DHP] incorporation to yield elongation at break values of nearly 15%. An increase on the electrical conductivity as a result of the IL incorporation into cellulosic matrices is found. The actuator performance of composites was evaluated, NaCMC/[Ch][DHP] showing the maximum displacement along the x-axis of 9 mm at 8 Vpp. Based on the obtained high electromechanical actuation performance, together with their simple processability and renewable nature, the materials fabricated here represent a step forward in the development of sustainable soft actuators of high practical relevance.

Highlights

Ionic liquids (ILs) are a diversified group of salts composed of organic cations and a variety of anions that usually present a melting temperature of below 100 ◦ C
cellulose nanocrystals (CNCs), methyl cellulose (MC), hydroxypropyl cellulose (HPC), and NaCMC have been blended with IL contents up to 40% wt
The morphology of the prepared films has been studied by scanning electron microscopy (SEM)

Summary

Introduction

Ionic liquids (ILs) are a diversified group of salts composed of organic cations and a variety of anions that usually present a melting temperature of below 100 ◦ C. This criterion is commonly used to distinguish molten salts and ILs [1]. Their outstanding properties such as low vapor pressure, high thermal, electrochemical and chemical stability, high density, and their inherent ionic conductivity make them suitable for the development of smart and multifunctional materials with new functionalities and applications [2,3]. ILs are Materials 2020, 13, 2294; doi:10.3390/ma13102294 www.mdpi.com/journal/materials

Methods

Results

Conclusion