Electrostatically assembled line-plane CNT@MXene networks densified by solution-driven in-situ cross-linking for thermally conductive and strain-sensitive flexible composites

Line-plane CNT@MXene hybrids are constructed via electrostatic assembly. • CNTs effectively suppress MXene restacking and improve dispersion. • In-situ cross-linking drives filler rearrangement and network densification. • The composites exhibit high electrical and thermal conductivity with flexibility. • The composites enable strain sensing and thermal management capabilities. Flexible electronics require elastomeric composites that integrate efficient thermal management, electrical conductivity, mechanical compliance, and stable sensing capability. However, MXene-based composites are often limited by nanosheet restacking, filler aggregation, and poor network stability in elastomer matrices. Herein, a line-plane CNT@MXene hybrid filler was constructed by electrostatic self-assembly and incorporated into solution-cross-linked PDMS (S-PDMS) through a solution-driven in-situ cross-linking strategy. The CNTs bridged adjacent MXene nanosheets and suppressed their restacking, while solvent-evaporation-induced polymer chain shrinkage promoted filler rearrangement and network densification. As a result, the CNT@MXene/S-PDMS composite achieved an electrical conductivity of 0.126 S/cm and a thermal conductivity of 1.57 W·m −1 ·K −1 at 14.0 wt% filler content, while maintaining good stretchability and resilience. The composite also exhibited stable conductivity under repeated deformation, sensitive strain-sensing behavior, and effective heat-dissipation performance in LED thermal management. This work provides an effective strategy for constructing stable hybrid conductive networks in flexible polymer composites for integrated thermal management and strain sensing. Download: Download high-res image (168KB) Download: Download full-size image