Fractional polarity, surface tension

Wu has proposed to separate the surface energy into non-polar (dispersion) and polar components (Eq. (2.12)). The subscripts d and p designate non-polar (dispersion) and polar components, respectively. The concept of the additive nature of surface energy components has been accepted by a number of researchers such as Fowkes ° and Meyer et al. The polar component of surface tension includes various dipole interactions and hydrogen bonding. The various components have been lumped together to simplify the discussions. The dispersion component includes the nonpolar fraction of surface energy. Fractional polarity is defined by Eq. (2.13) and non-polarity by Eq. (2.14). 

The harmonic mean equation is generally considered to be applicable to low surface tension materials such as organic polymers and liquids. If y and yP are known for two liquids, and the contact angles of those liquids on the solid of interest are measured, equation (36) produces two simultaneous equations that can be solved to find the surface tension and polarity of a solid polymer surface. Numerous assumptions have been made in developing the theory of fractional polarity. For example, it ignores the possibility of induced polarity at the interface between polar and nonpolar materials (80). These assumptions limit the application of equation (36) to systems where at least one and preferably both of the... 

The wetting behavior of polymers is reviewed beginning with the thermodynamic conditions for contact angle equilibrium. The critical surface tension of polymers is discussed followed by some of the current theories of wettability, notably the theory of fractional polarity and theories of contact angle hysteresis. The nonequilibrium spontaneous and forced spreading of polymer liquids is reviewed from two points of view, the surface chemical perspective and the hydrodynamic perspective. There is a wide di.sperity between these two viewpoints that needs to be resolved inorder to establish the predictive relations that govern spreading behavior. 

For macroscopic bodies dispersed in water the cavity creation may be the most important contribution. This could be related to the surface tension of water, which at room temperature is 72 mN m (Table 1.2), much larger than those of non-polar liquid solutes, ys < 30 mN m and to the surface area of the cavity accommodating the solute. As. The relevant expression for the mole fraction solubility for solutes that are liquid in their standard state is then, in analogy to Eq. (1.22) ... 

Auto ignition temperature Upper flammability limit Lower flammability limit Viscosity Refractive index Solubility in water Solubility of water Solubility parameter Hydrogen bond index Fractional polarity Nitro cellulose dil ratio Nitro cellulose dil ratio Surface tension Specific heat liquid Latent heat Dielectric constant Antoine constant A Antoine constant B Antoine constant C Heat of combustion UN number IMO classification ADR/RID classification UK exposure limits USA exposure limits German exposure limits EU classification EU risk phrases EU safety phrases... 

Hydrogen bond index Fractional polarity Nitro cellulose dil ratio Nitro cellulose dil ratio Surface tension mN/m 20 °C ... 

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