Hello, I'm doing an MSc project concerned with the treatment of plastic polymers with an μ-APPJ. I have been getting a tonne of results on different plastics using an APPJ of He carrier gas with an Oxygen admixture of 1/2, 1 & 2%. However, in my analysis I'm unsure of what the dispersive component of the surface energy is and why it more or less stays the same. Can someone give me a definition of what it is? I think its to do with van der waals but nothing on the net is giving me a good answer. Is it supposed to stay the same irrespective of whether the material has been heated up or its polar component increases? How would I interpretate my data on the surface energies for example: For convention, -5mins to 0mins is the 5minutes of plasma treatment. I'm not measuring the plastic during this time, hence the constant values and the discontinuity when I first measure it after treatment. This is one of my preliminary results with Acetate plastic. Treated 1 run with He gas, 2nd run with He + O2. The legend will tell you. The dispersive components stay relatively the same, why?