We used the sessile drop technique (16,17) with a goniometer to measure the contact angle, which was then used to calculate the surface free energy.
Using the sessile drop technique, water and dodecane were used to measure contact angles, However, dodecane spread too quickly and flat to be read over 13 of the samples so diiodomethane was used for those 13 samples as the second required contact angle measurement used to calculate surface energy.
Thus the surfactant type does not affect strongly the value of the contact angle measured by sessile drop technique
but it affects overall distribution of PPT particles in the composite and its mechanical properties, investigated after long period of time and after certain thermal treatment of composite.
The sessile drop technique
was used for contact angle measurements with a NRL goniometer (Rame-Hart, Inc.
The investigation will use sessile drop techniques
to characterize mold metal interface reactions.
It was found that methods based on static measurements, such as the ring tensiometer and the sessile drop techniques
, give values of interfacial tension lower than dynamical methods, such as the drop deformation technique.