adhesion

[Muzialis]

Hi All,

I was wondering about suitable ways to determine the adhesion between two surfaces bonded together chemically.
I have seen this being done on a machine which measures the load necessary to separate them, but I can not see more than a correlation with adhesion, as in this case I am inclined to think other factors ( surface energy? polymer tear properties?) get into play.

At this stage all I would like to know the maximum pressure force the bonding agent is providing.

Any advice or source to look at would be very welcome.

Thank you very much.

All the best

Muzialis

[Jorgen]

Interesting question. Here are a few comments:

- Isn't is fair to say that the adhesion between two surface can in general have contributions from multiple sources (such as surface energy, tear properties, etc)? If so, I would think that a test machine that measures the force required to separate the two surfaces would be acceptable.

- There are other interesting techniques that can be used. For example the laser spallation technique (http://gupta.seas.ucla.edu/Research%20Interests/interface_science.htm) developed by Prof. Vijay Gupta at UCLA.

[Muzialis]

I can see your point.

The problem is that the measured load refers to the interface between two surfaces where a crack has been induced prior to the test:one side is clamped into a moving leg which gives the load as the crack moves along the interface.
I do not see a way to translate this into the maximum pressure the bonding can withstand.
Just for a play I had a go at modelling the two surfaces assuming the load was the one corresponding to incipient further separation: the stress at the tip is so mesh dependent that I found any result useless, but this of course might be to my poor modelling skills ( please feel free to comment on this point as well, how to model such a steep stress concentration).

It seems to me as if the modulus was to be determined by a tear test, which I believe would be wrong.

Thank you very much for your answer however and for the interesting link.

Muzialis