Composite Material Curing Micro-nano Sensor Monitoring And Sensing Mechanism Research

In this paper,two micro-nano sensors were prepared by jet suction filtration process through the study of carbon nanomaterials.Buckypaper sensor and graphene/carbon nanotube sensor.In order to study the curing monitoring of composite materials,the sensor is embedded in the composite material.The sensor is integrated with the composite material to monitor the resin curing process online.The phase change of the resin,the degree of solidification and the gel point can be determined by the resistance change of the sensor.First,the application of buckypaper sensor was studied.The buckypaper sensor is embedded in the composite material to monitor the resin curing online,and a vacuum bag forming process is adopted.The experiment set up six different curing systems to analyze the resistance response of the sensor during the cooling phase.The results show that the temperature coefficient of resistance of the buckypaper sensor is related to the curing behavior of the resin.The critical value of the temperature coefficient of resistance is determined to be-7.18×10^-4?^-1.When the temperature coefficient of resistance is greater than the critical value,the resin molecular chain forms a stable three-dimensional network.The complete cure of the resin should meet the temperature coefficient of resistance of the buckypaper sensor,which is also consistent with the results of differential scanning calorimetry?DSC?testing.The application of graphene/carbon nanotube sensor was then discussed.The sensor is embedded in the composite material and the composite material is fabricated by a compression molding process.The resin phase change and gel point are monitored online during the composite manufacturing process.The resistance of the graphene/carbon nanotube sensor is obtained by a resistance meter,and the resistance change may be related to the phase transition of the resin matrix.The gel point of the composite obtained by dynamic mechanical analysis?DMA?as a baseline is compared with the output of the graphene/carbon nanotube sensor.The results show that graphene/carbon nanotube sensor embedded in composite laminates can respond to resin phase transitions.The resin gel point obtained from the graphene/carbon nanotube sensor was 134?,and the DMA result is substantially the same at 137?.