In situ monitoring of sandwich structure in liquid composite molding process using multifunctional MXene/carbon nanotube sensors.

This paper prepares a flexible MXene/CNT film by layer‐by‐layer (LbL) self‐assembly process. Based on excellent conductivity and good compatibility with resin, MXene/CNT can be used for on‐line monitoring of large and complex liquid composite molding (LCM). In this paper, the MXene/CNT will be used as a novel micro‐nano sensor. The MXene/CNT sensor is embedded between the sandwich layers of the sandwich composite structure. The resistance information of the MXene/CNT sensor was collected by online monitoring system during LCM. The tube cross‐linked network's conductive model will be established to reveal the resistance response sensing mechanisms of MXene/CNT sensors and the response rules of resin flow states and resistance signals. Using the real‐time monitoring information collected by the MXene/CNT sensor, combined with Darcy's law, the comparison results of different permeability are obtained. The monitoring results show that polyvinyl chloride (PVC) interlayer significantly influences the resin flow trend and penetration of the core layer. Simultaneously, the interlayer's presence will also affect the resin flow trend and penetration of the lower layer of the PVC sandwich layer. The research results will provide theoretical guidance and technical support for designing process parameters and in situ real‐time monitoring of LCM in the engineering industry. [ABSTRACT FROM AUTHOR]