Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
Electrical Conductivity of Composite Material
Posted 03.05.2021, 02:31 GMT-4 Electromagnetics, Low-Frequency Electromagnetics Version 5.6 3 Replies
Please login with a confirmed email address before reporting spam
Hello All!
I have been attempting to model a composite material, specifically a resin that contains conductive nanofillers. In my case, my model is a cube (which represents the resin) containing graphene nanoplatelets (1 nm thick) and silver nanoparticles (10 nm in diameter) dispersed in an arrray throughout the model. The hexagonal features are the nanoplatelets, and the silver nanoparticles are dispersed throughout (not visible). I am utilizing the 'electric currents (ec)' study to model the potential through the resin. The trouble I am having is that in conductivity lab studies performed on similar composites, there is a conductivity observed associated with the resin. However, I cannot seem to replicate that in COMSOL. The image pasted below demonstrates a bird's eye view of the potential gradient as seen from the x-y plane. The terminal is the bottom face/edge, and the ground is the top face/edge. How can I reflect the conductivity of the resin in the study?
Please login with a confirmed email address before reporting spam
You don't say how you are modeling the materials. However- if the the resin is modeled by an insulator- there will be zero current unless there is a continuous path through conductive objects between the electrodes.
As usual, it would be a good idea to post your (reduced-size) model.
Please login with a confirmed email address before reporting spam
I am running a stationary study, where I have assigned one face of the cube (representing the resin) as the terminal, and the opposing face of the cube as the ground. The silver nanoparticles and graphene nanoplatelets have both been assigned their respective materials with conductivities in the 10^3 S/m regime, and the resin encasing them has been assigned 10^-14 S/m. The initial potential is set to 1V. The study is being run with the iterative solver (@ 100 iterations). I have attached the reduced size model.
Attachments:
Please login with a confirmed email address before reporting spam
If the conductivity of the resin is 1e-14, and there are no continuous paths through the inclusions, then the right answer is zero current. Well, maybe 1e-14 A.
At these small dimensions, is tunneling or field emission expected? Neither of these are modeled in the ec module.
(By the way, your model doesn't build properly for me so I can't run it.)