Crosslinking network design of cellulose-based conductive gels: Mechanism, strategies, and characterization

Abstract

Cellulose-based conductive gels represent a unique platform for integrating intelligent electronic devices seamlessly into daily life due to their excellent flexibility, adjustable three-dimensional (3D) structure, and sustainability. Mechanical strength and conductivity, as two key parameters, play significant roles in this process. Nevertheless, transferring excellent mechanical properties and conductivity to 3D gels simultaneously poses numerous challenges due to their inherent conflict in typical cases. The advancements in functionalizing crosslinking networks at the single cellulosic material level and within the constructed cellulose-based 3D matrix have fundamentally altered their utility. This review provides a systematic and in-depth understanding of designing advanced crosslinking networks in developing cellulose-based conductive gels with superior mechanical strength and conductivity. Here, we introduce the advantages of cellulose in designing conductive gels and the component effect of the gels on mechanical and conductive properties. Then, we systematically summarize the importance and design methods of crosslinking network engineering in balancing these features theoretically. Furthermore, fabrication strategies for achieving superior mechanical strength and enhanced conductivity through structural optimization of cellulose-derived crosslinking networks are investigated, with particular emphasis on interfacial engineering and functional integration mechanisms. We further review the compatibility of crosslinking networks and other key properties (self-healing and low-temperature tolerance). We also discuss advanced analysis methods of structure-performance relationship for developing novel cellulose-based conductive gels with superior physicochemical characteristics. Finally, we introduce potential applications and highlight key technologies to broaden the application prospects of cellulose-based conductive gels for smart wearable devices.