Development of carbon-black-epoxy-based sensors for monitoring water ingress in composite materials 

Adverse water accumulation in composite structures can lead to corrosion, a gain of undesired weight and even a loss of structural coherence e.g. in sandwich materials. Therefore, a network of sensors permanently surveying water uptake should be used to monitor the structural integrity of composites and prevent failure in the long run. Filler-reinforced materials, made of an insulating polymer matrix filled with conductive fillers, are promising percolation sensors giving a sigmoidal resistive response curve that usually ranges over multiple orders of magnitude caused by swelling of the matrix induced by water sorption. The probability of detecting critical levels of moisture is then superior with respect to linear or quasi-linear humidity sensors. Carbon Black fillers (CB) and thermal-resistant epoxy were selected as they are promising materials for producing low-cost humidity sensors that can be seamless integrated to composite structures during manufacturing. However, the electrical behavior of CB-epoxy nanocomposites upon water aging has scarcely been investigated and methods for embedding such sensors in composite structures on a large scale are yet to be developed. Therefore, this project aims at better understanding the interaction of water with the electrical percolation network in carbon-black-epoxy nanocomposites. Sensors with optimized filler-to-matrix ratio and dispersibility will be produced and, then embedded during manufacturing of e.g. sandwich composites.   

People involved: Rémy Fauche 

Period: 2021-2025 

Funding scheme: Industrial Research fund 

For more information: