Chewing gum residue is hard to decompose and easy to cause pollution, which is highly desirable to realize the recycling. In this paper, a chewing gum gel with enhanced mechanical properties and self-healing properties is prepared by using polyvinyl alcohol (PVA) as the backbone in chewing gum residue. The hydrogen bond and the borax ester bond are employed to construct reversible interaction to enhance the self-healing ability. The physical crosslinking is realized by further freeze-thaw treatment to improve its mechanical properties. The gel demonstrates high elongation at break of 610% and strength of 0.11 MPa, as well as excellent self-healing performance and recyclable property. In particular, the gel with a fast signal response is successfully applied as a wearable strain sensor to monitor different types of human motion. The gel as a sensor exhibits self-healing properties suggesting superior safety and stability, and displays wide linear sensitivity (the gauge factor is 0.417 and 0.170). The gel can be further served to explore temperature changes, implying the application in temperature monitoring. This study develops a novel approach for the recycle and reuse of chewing gum residue. The obtained gel may be a promising candidate for the fabrication of flexible wearable sensor. This article is protected by copyright. All rights reserved.

A Chewing Gum Residue-Based Gel with Superior Mechanical Properties and Self-Healability for Flexible Wearable Sensor.

Solid propellant liner with high anti-migration and strong adhesion based on isocyanate-functionalized graphene oxide and hydroxy-terminated polybutadiene

High-stretchable, self-healing, self-adhesive, self-extinguishing, low-temperature tolerant starch-based gel and its application in stimuli-responsiveness.

Chitosan-based thermal insulation compressible foam enhanced with high performance of piezoelectric generation and sensing.

Spider silk possesses the combined properties of high strength, great toughness, and good elasticity due to the unique two-phase structures, in which the β-sheet nanocrystals consisting of hydrogen-bonded polypeptide chains are connected by the flexible chains. The spider-silk-like structures provide novel avenues to create functional materials. Herein, a novel yet simple strategy has been developed for the fabrication of spider-silk-like ionogels. The scaffolds of ionogels, polyurethane (scPLA-PEG), were prepared from poly(L-lactide) (PLLA), poly(D-lactide) (PDLA), and poly(ethylene glycol) (PEG). The stereocomplex nanocrystallites (sc) could be formed through the multiple hydrogen-bonds on the enantiomeric PLLA and PDLA chains, thus the as-prepared scPLA-PEG possesses the spider-silk-like two-phase structures, in which the stereocomplex nanocrystallites are cross-linked by the amorphous PEG phases. As compared, the scPLA-PEG exhibit much higher mechanical properties than the pristine PLA counterparts. The scPLA-PEG ionogels also display good mechanical properties, extremely temperature-tolerant flexibility that endures twisting at low temperature (−30 °C) and stretching at high temperature (70 °C). Furthermore, the scPLA-PEG ionogels can be easily recycled owning to the reversible properties of scPLA. The results would present a new insight into designing novel functional ionogels with distinguished mechanical properties, tractable recyclability, and biodegradability, which will promote the sustainable flexible electronics. 

Xiangling Gu

Papers

The preparation of dual cross-linked high strain composite gel with manifold excellent properties and its application as a strain sensor