Poly wettability measurements

VV -values for bromoform and pyrrole, acidic liquids, against poly(vinyl chloride), an acidic polymer, and dimethyl sulfoxide, a predominantly basic liquid, against polyfmethyl methacrylate), a basic polymer, but large values for the acidic liquids against PMMA and the basic liquid against PVC. 2-Iodoethanol, a bifunctional liquid, showed appreciable -values with both polymers. Despite these results in line with expectations, other results based on wettability measurements are not so clear-cut. For example, Vrbanac [94] found significant apparent acid-base interactions of various aromatic liquids against poly(ethylene), presumably a neutral substrate. 

The energy contribution from the MDS study was found mainly from the van der Waals interaction, being less favorable for the poly (ester)s with one Si (la) than with one Ge atom (lb). These results have been in good agreement with the dispersion contribution to the total surface energy which was estimated by wettability measurements [46],... 

The validity of this approach has established on the basis that IGC and wettability measurements lead to approximately the same yf value for poly(ethylene tereph-thalate) [28]. Furthermore, Dorris and Gray stated that the molecular area could be an adjustable parameter. 

The adhesion force of pad particles on the poly-Si wafer surfaces was measured in the KOH solution (pH 11) as a function of polysilicon wettability, which was varied by treating the surface with different concentrations of the oxidizer. As shown in Fig. 16.14, the adhesion force decreases and then levels... 

Water-extruded blends of poly(ethylene-co-propene) with various amounts of poly(ethylene-co-vinyl acetate) (PPE/EVA blends) were prepared and the wettability and the i -potential were measured [ 100]. The relationship of the varying wettability and surface charge values and defined blood compatibility parameters is shown in Figs. 10 and 11. Figure 10 demonstrates the blood compatibility parameters (APTT, number of thrombocytes and leucocytes) after blood/mate-rial interaction with respect to the parameters before exposition X/Xq as a function of the ratio of the dispersive and the polar component of the surface tension (y//YsP). The best blood compatibility, that means X/Xo=l, was obtained for a ratio of the dispersive and polar component of ca. 12, which corresponds to the surface tension of the PPE/EVA blend with an EVA content of 50 wt%. Probably the balanced ratio between the hydrophilicity and the hydrophobicity of the PPE/EVA blend (50 50) is responsible for the good blood compatibility. 

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