High Dielectric Nonpolar Interfacial Layers Derived from Nanocellulose for Electrowetting Devices

Abstract

A dielectric material is a particular type of insulator that does not conduct electricity but gets polarized when subjected to electricity, which is a crucial part of electronics such as cables, capacitors, displays, transformers, etc. Currently, synthesizing a nonpolar dielectric remains challenging. In this study, a method to make a high dielectric and nonpolar fluoropolymer and its nanocomposites based on cellulose nanocrystals (CNCs) by grafting it with nonpolar polymer 2,2,2-trifluoroethyl methacrylate is reported. A high dielectric constant but nonpolar nanocellulose material is obtained for the first time. This material has an anisotropic arrangement of dipoles with a high polarizability effect, thereby displaying excellent dielectric properties (e.g., dielectric constant and loss: 8.59 and 0.017 at 10 kHz) and high stability (dielectric constant at 8.21 at 1 MHz). The dielectric material is miscible as an additive with other commercial fluoropolymer plastic, which demonstrates a high breakage voltage ranging from 4.6 to 9.2 kV/0.1 mm. When it is used as an interfacial layer in electrowetting display devices, it also demonstrated a low voltage driven and fast-response effect. The excellent dielectric performances allow to develop more high-performance dielectrics and electronics such as memories, sensors, actuators, wires, and film capacitors.