Smart Sealants witih graphene: Monitoring Properties With Eddy-current Sensing

Purpose and goal:

The objective of this project was to develop a conductive sealant based on graphene whose mechanical properties can be monitored with eddy-current sensors and correlated to sealing force and material properties without the need for electrodes. It was the goal of this project to correlate the change in material properties over time to the eddy-current signal obtained and this was achieved.

Expected results and effects:

The result from the literature study showed that little has been done in the area of rubber and insulative material properties being monitored with eddy current methods. This has been mostly limited to characterization of metal materials. Samples were made by Trelleborg of EPDM rubber with a range of types and amounts of graphene and carbon black.

The materials were exposed to accelerated aging and characterized in terms of physical properties, and eddy current sensor. The properties could be correlated to eddy-current signal without the need for electrodes. Approach and implementation:

First there was a literature review of what has been done in terms of sensors and sealants along with using eddy current sensing technology on polymer materials. Trelleborg produced a range of EPDM rubber sealants. A standard formulation was used with of carbon black of 10-40 wt% and measured by eddy-current technique.

The 30 wt% carbon black formula was then modified with 0,5-5,5 wt% 25 um graphene flake. These were then aged and the samples measured for eddy current(EC) signal and mechanical properties before and after aging to correlate EC signal to the changing material properties.