MXene‐Reinforced Cellulose Nanofibril Inks for 3D‐Printed Smart Fibres and Textiles

Abstract

Fibre-based materials have received tremendous attention due to their flexibility and wearability. Although great efforts have been devoted to achieve high-performance fibres over the past several years, it is still challenging for multifunctional macroscopic fibres to satisfy versatile applications. 2D transition metal carbides/nitrides (MXenes) with intriguing physical/chemical properties have been explored in broad application, and may be able to reinforce synthetic fibres. Inspired by natural materials, for the first time, flexible smart fibres and textiles are fabricated using a 3D printing process with hybrid inks of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxylradi-cal)-mediated oxidized cellulose nanofibrils (TOCNFs) and Ti 3 C 2 MXene. The hybrid inks display good rheological properties, which allow them to achieve accurate structures and be rapidly printed. TOCNFs/Ti 3 C 2 in hybrid inks self-assemble to fibres with an aligned structure in ethanol, mimicking the features of the natural structures of plant fibres. In contrast to conventional synthetic fibres with limited functions, smart TOCNFs/Ti 3 C 2 fibres and textiles exhibit significant responsiveness to multiple external stimuli (electrical/photonic/mechanical). TOCNFs/Ti 3 C 2 textiles with electromechanical performance can be processed into sensitive strain sensors. Such multifunctional smart fibres and textiles will be promising in diverse applications, including wearable heating textiles, human health monitoring, and human-machine interfaces.

A Facile, High‐Yield, and Freeze‐and‐Thaw‐Assisted Approach to Fabricate MXene with Plentiful Wrinkles and Its Application in On‐Chip Micro‐Supercapacitors

“…MXene, an intriguing member of 2D nanomaterial family, is endowed with the amalgamation of superior electrical conductivity, large specific surface area, and hydrophilic surfaces, and has been widely used in Li‐ion batteries, electrochemical storage systems, electromagnetic interference shielding, electrocatalysts, photo‐to‐thermal conversion, etc. Up to now, over 20 species of 2D MXenes have been reported .…”

MXene-based Sensors for Detecting Human Physiological Information

“…Meanwhile, Li et al and Cao et al demonstrated MXene-based sensors that can capture real-time human physiological signals such as small deformation of epidermis and muscle to identify human voices and word pronunciations. (6,36) The pressure sensors comprising MXene chitosan polyurethane flexible sponges designed by Li et al could distinguish and categorize human voices into different patterns with a short response time according to different strain signal patterns of resistance changes from the sponge sensor when testers pronounced "car" and "bon" from "carbon". (36) The hybrid inks of 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-mediated oxidized cellulose nanofibrils (TOCNFs) and Ti 3 C 2 MXene textile strain sensor proposed by Cao et al exhibited attractive performance, such as high sensitivity and durability, and could detect subtle physiological signals, for example, it could accurately distinguish different polysyllabic words such as "hello" and "Ni Hao" (Chinese for "hello").…”

“…(36) The hybrid inks of 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-mediated oxidized cellulose nanofibrils (TOCNFs) and Ti 3 C 2 MXene textile strain sensor proposed by Cao et al exhibited attractive performance, such as high sensitivity and durability, and could detect subtle physiological signals, for example, it could accurately distinguish different polysyllabic words such as "hello" and "Ni Hao" (Chinese for "hello"). (6) In addition to detecting human body motion, MXene-based sensors have high potential to capture subtle movements like the deformation of muscles. The sensor proposed by Guo et al could accurately detect body movement and assist medical diagnosis and treatment by clinicians.…”

“…MXenes were discovered in 2011 by Gogotsi and coworkers. (2,3,(6)(7)(8)(9)(10) MXenes are typically synthesized from the parent MAX phases (M n+1 AX n with early transition metals (group 13-16 elements), carbon, and nitrogen, with n = 1-4) by strong acid etching the layer obtained by intercalation-assisted delamination. MXene (M n+1 X n T x ) flakes with a high aspect ratio (up to ≈106) and abundant terminating functional groups (T x ) are desirable for producing polymer composites with novel functionalities.…”

Fabrication of Mo1.33CTz(MXene)–cellulose freestanding electrodes for supercapacitor applications

“…3D printed textiles, 45 wearable sensors, 19 and supercapacitors. 46,47 For example, S. Jiao et al reported the use of Ti 3 C 2 T z MXene and bacterial cellulose in stretchable and flexible all-solid-state microsupercapacitors.…”