Cellulose-Based Conductive Films with Superior Joule Heating Performance, Electromagnetic Shielding Efficiency, and High Stability by In Situ Welding to Construct a Segregated MWCNT Conductive Network

Abstract

Developing eco-friendly, robust, and multifunctional conductive polymer composites is highly desirable for using as flexible wearable electric elements and meeting the requirements of a sustainable society. Herein, we construct multifunctional cellulose/MWCNT composite films with a superhigh Joule heating performance, outstanding electromagnetic interference (EMI)-shielding efficiency, high electrical conductivity, good mechanical properties, excellent thermostability, and adequate water resistance. The resultant cellulose/MWCNT composite films possess a special segregated MWCNT conductive network structure by using a simple paper-making process and a subsequent in situ welding process with an ionic liquid as the solvent of cellulose. Their EMI-shielding effectiveness reaches 49.2 dB with a thickness of 0.3 mm, their electrical conductivity reaches 1901 S/m, their tensile strength reaches 110 MPa, and their initial decomposition temperature is higher than 300 °C. In particular, they show a superhigh Joule heating performance at a low driving voltage. When the driving voltage is as low as 2 V, the temperature of the cellulose/MWCNT composite rapidly increases to 166 °C, which is dramatically higher than those of the previously reported polymer composite heaters. Cellulose/MWCNT composite films with such an outstanding combination performance can be used as multifunctional flexible conductive elements for the fabrication of a deicing device, a portable heat sealer, and an EMI-shielding device.

Research Progress on the Preparation of Flexible and Green Cellulose-Based Electrothermal Composites for Joule Heating Applications

“…This film was successfully applied in deicers and portable heatsealing devices (Figure 9e,f). 124 The dilemma of window frost accumulation affects the daily lives and driving safety of people. Transparent electrothermal polymer composites have been reported to exhibit efficient defrosting properties.…”

“…Cellulose/MWCNTs film in (e) deicers and (f) heat sealers. (Panels d–f) Reprinted with permission from ref . Copyright 2022 American Chemical Society.…”

Thermally conductive polymer-based composites: fundamentals, progress and flame retardancy/anti-electromagnetic interference design

“…56 Cellulose/MWCNT composite films with high thermal conductivity by filtration and drying were fabricated, whose best electromagnetic interference shielding effectiveness was 49.2 dB only with a thickness of 0.3 mm. 181…”

“…Fabricating multifunctional polymer-based composites of high thermally conductive properties and excellent anti-electromagnetic-interference performance is highly urgent to meet the requirements of consumers and a sustainable society. 181 The design of materials with high anti-electromagnetic-interference performance has in the recent years become a research hotspot. 182 According to the structural design, the materials can be classified into four categories: uniform structure, isolation structure, multi-layer structure and foam structure.…”

“…56 Cellulose/MWCNT composite films with high thermal conductivity by filtration and drying were fabricated, whose best electromagnetic interference shielding effectiveness was 49.2 dB only with a thickness of 0.3 mm. 181 3D printing technology was used to gain ordered graphite nanosheets/poly(lactic acid) sheets and combined Ti 3 C 2 T x films by ''layer-by-layer stacking-hot pressing'' technology to fabricate Ti 3 C 2 T x /(o-GNPs/PLA) composites, which had excellent electromagnetic interference shielding effectiveness and thermal management performance. 217 The electromagnetic interference shielding effectiveness reached 65 dB (3 mm), and the thermal conductivity reached 3.44 W m À1 K À1 with 18.60 wt% GNPs and 4 layers of Ti 3 C 2 T x (6.98 wt%) films (Fig.…”