β Scribed by Renato Norio Shimizu; Nicole Raymonde Demarquette
No coin nor oath required. For personal study only.
In the present work, contact angles formed by drops of diethylene glycol, ethylene glycol, formamide, diiodomethane, water, and mercury on a film of polypropylene (PP), on plates of polystyrene (PS), and on plates of a liquid crystalline polymer (LCP) were measured at 20Β°C. Then the surface energies of those polymers were evaluated using the following three different methods: harmonic mean equation and geometric mean equation, using the values of the different pairs of contact angles obtained here; and Neumann's equation, using the different values of contact angles obtained here. It was shown that the values of surface energy generated by these three methods depend on the choice of liquids used for contact angle measurements, except when a pair of any liquid with diiodomethane was used. Most likely, this is due to the difference of polarity between diiodomethane and the other liquids at the temperature of 20Β°C. The critical surface tensions of those polymers were also evaluated at room temperature according to the methods of Zisman and Saito using the values of contact angles obtained here. The values of critical surface tension for each polymer obtained according to the method of Zisman and Saito corroborated the results of surface energy found using the geometric mean and Neumann's equations. The values of surface energy of polystyrene obtained at 20Β°C were also used to evaluate the surface tension of the same material at higher temperatures and compared to the experimental values obtained with a pendant drop apparatus. The calculated values of surface tension corroborated the experimental ones only if the pair of liquids used to evaluate the surface energy of the polymers at room temperature contained diiodomethane.
π SIMILAR VOLUMES
A Response Surface Methodology approach to correlate the solubility data of solids in supercritical Β―uids directly to the pressure and temperature is described. Published data for 2,6dimethylnaphthalene, 2,3-dimethylnaphthalene, phenanthrene and benzoic acid in both supercritical carbon dioxide and
## Abstract The laminar liquid rivulet flow on an inclined flat metal plate and wavy metal plate is taken as a test case to validate the CFDβsimulation results using the VOF (Volume of Fluid) multiphase flow model. The local rivulet thickness was measured using an optically assisted mechanical sens
A method is described for correcting the binding energy scale for specimen charging that occurs during XPS analysis of insulating samples. A small quantity of polymeric poly (dimethyl silicone) (PDMS) is deposited from solution onto the surface of a series of polymers. After XPS analysis, the bindin