Dipolar interactions and normal stress

Having established the accuracy and reliability of the slab-adapted three-dimensional Ewald method, we present in this paragraph numerical results from GCEMC simulations (see Section 5.2.2) for a confined Stockmaycr fluid. The particles then interact with each other via both the long-range. 

For technical reasons explained in Section 5.2.2, the GCEMC simulations have been performed using a slightly modified Stockmayer potential defined 

The GCEMC results presented in this section refer to Stockmayer fluids at a temperature T = 1.60 and dipole moment m = 2.0, which are typical for real polar molecular fluids [259]. The chemical potential is set equal to fi = —19.30, so that the bulk fluid has an average mean density of p 0.6. Keeping these parameters fixed, we investigated systems with substrate separations. s in the range 1.7 . s 10.0. 

In the following we focus on the normal stress, or rather on the disjoining pressure / (Sz) defined in Eq. (5.57) for reasons given in Section 5.3.2. Numerical results for /(s ) are presented in Fig. 6.3, where the dipolar contribution to Tzz has been calculated according to the microscopic expressions given in Eqs. (F.124)-(F.126) in Appendix F.3.2. 

As before for confined fluids with short-range interaction potentials, the disjoining pressure / (sj) has damped oscillatory character with the oscillations vanishing when the confined systems become bulk-like at large wall 

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