Water, surface energy components

Table 3.15 Surface Energy Components of Benzene, Ethanol, and Water and Their Contact Angles on an OTS/PTW Wafer...

Using this expression for water—hydrocarbons interfacial tension (y h) die dispersive surface energy component of water may be found. As basic components for hydrocarbons should be zero, the dispersive component is the surface tension of the hydrocarbon. Measuring yu, Yw> and YwH die only unknown is y which turns to be... 

Table IV exemplifies the surface energy properties of some plasma polymers (data from Tables I and II, columns A) and their conventional counterparts. The surface energy components for conventional polymers were calculated from contact angle data of water/methylene iodide system reported by Shafrin et al. There are also specified the densities of plasma polymers and conventional amorphous counterparts, respectively. The data in Table IV clearly indicate that plasma polymers have higher surface energy as compared to their conventional counterparts. This apparently results from the increased dispersion and polar (except PP-VDC) components of their surface energy. The increase in y noted...

The polar and dispersion components of the surface energy are generally obtained using two liquids, for example water and formamide. To calculate yf and y/, the following values for y/ and yf were taken [3] ... 

The dispersive and polar components of the surface tensions of the liquids were estimated to be 7 = 21.8 mN/m and 7 = 51.0 mN/m for water and 7 = 49.5 mN/m and 7 = 1.3 mN/m for methylene iodide. This estimation was done by measuring contact angles with various hydrocarbons and assuming that there are only nonpolar interactions. What are the surface energies, 7s, of the polymers ... 

The O Is spectra in Fig. 4.6 show an additional small emission at higher binding energies. The energy difference between the ZnO-related emission at 530-531 eV and the high binding energy component amounts to 1.6-1.8 eV. Such a species is always observed on ZnO surfaces. In literature, it is mostly attributed to adsorbed species. These include water and hydroxides... 

As a second model potential we shall briefly discuss the PES for the water dimer. Analytical potentials developed from ab initio calculations have been available since the mid seventies, when Clementi and collaborators proposed their MCY potential [49], More recent calculations by dementi s group led to the development of the NCC surface, which also included many-body induction effects (see below) [50]. Both potentials were fitted to the total energy and therefore their individual energy components are not faithfully represented. For the purposes of the present discussion we will focus on another ab initio potential, which was designed primarily with the interaction energy components in mind by Millot and Stone [51]. This PES was obtained by applying the same philosophy as in the case of ArCC>2, i.e., both the template and calibration originate from the quantum chemical calculations, and are rooted in the perturbation theory of intermolecular forces. 

CaCO EPR rubber rubber silicone maleates fatty acid silanes PDMS decreased disperse component of the surface energy filler surface energy approaches surface energy of matrix decreased tensile strength and flexural cracking increased green strength, Mooney viscosity, and tensile properties surface hydrophobization resistance to solvent extraction and water 21 49 49 37... 

Repellent finishes are important components of many protective textiles. Apphca-tions for repellent textiles range from medical textiles to raincoats. The low surface energies provided by repellent finishes can keep solid and liquid soils from adhering to treated fiber surfaces. Finishes based on hydrocarbon and silicone chemistries can yield water repellent textiles, while fluorochemicals are necessary to achieve the low surface energies needed for dry soil and oil repellency. "... 

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