Bubble-Templated Design of Superelastic Cellulose Foam as a Durable Ionotropic Sensor

Abstract

Introduction of superelasticity and electric conductivity into ecofriendly and biocompatible cellulose-based foams is highly in pursuit for applications in wearable sensors, artificial skin, and soft robotics. Nevertheless, producing superelastic materials with electric conductivity often fails due to the mechanical brittleness and dielectric feature. Herein, we designed a novel type of regenerated cellulose foam with electric conductivity, superelasticity, and negative Poisson's ratio by combining an air bubble template and ionic liquid modification process. The pore size and density could be controlled between 60 and 750 μm and 74.4 and 125.5 mg cm −3 , respectively, by tuning the vacuum degree during the regeneration process. With the presence of cellular microstructures and ionic liquid, this regenerated cellulose foam could reach a high compression strain of up to 90% with a negligible plastic deformation and showed superflexible mechanical performance (tensile yield strain of ∼25%, torsion to 720°, and bending to 180°), together with stable ionotropic conductivity. Both the superelasticity and conductivity could be maintained even after more than 10 3 cycles of periodic compression. Thus, this novel type of regenerated cellulose foam would be capable of serving as elastic biomaterials and promise applications in many flexible devices.

Plant bio-inspired laminar cellulose-based foam with flame retardant, thermal insulation and excellent mechanical properties

“…3l) show typical cellulose I crystalline diffraction peaks at 2 θ = 14.5°, 15.6° and 22.5°, respectively, with three characteristic peaks corresponding to the (11̄0), (110), and (200) diffraction crystal planes of cellulose I, respectively. 33…”

Cellulose processing in ionic liquids from a materials science perspective: turning a versatile biopolymer into the cornerstone of our sustainable future

“…Addition of a surfactant to the cellulose/ionic liquid solution can help the formation of large μm-sized pores, as reported by An et al 237 In their work, cellulose was dissolved in [Amim][Cl], followed by the addition of sodium dodecyl sulphate (SDS) and vigorous stirring to facilitate foaming. By adjusting the cellulose concentration and the amount of the air phase, a stable biphasic system could be obtained.…”

Modeling Xanthan Gum Foam’s Material Properties Using Machine Learning Methods

“…In order to tackle this issue, researchers have explored the utilization of renewable resources in foam production, with a focus on materials that are sustainable, biodegradable, and recyclable [ 3 ]. Several natural polymers, such as chitosan [ 4 ], starch [ 5 ], alginate [ 6 ], and cellulose [ 7 ], have been utilized for this purpose. Cellulose is a widely used natural polymer that is safe, eco-friendly, and abundant in nature.…”