In this thesis, we have reported two general analytic equations for lateral and normal components of the pressure tensor of confined fluids in nanoslit pores using virial theorem and also study dynamic properties of such systems via dynamical density functional theory. A particular properties of these fluids is the tensorial character of pressure with P ij components, where i , j = x,y,z. In nanoslit pores with structureless walls containing a stationary confined fluid, the off-diagonal components of the pressure tensor are zero. So in such systems pressure is a diagonal tensor with normal and lateral components. In the first part, we have predicted local behavior of both normal and lateral components using virial theorem. Our derived equations are applicable for much kind of fluid-fluid and fluid-wall interactions. So, both of the resulting equations has been numerically solved for the confined hard-sphere fluid. Our calculations show the lateral and normal pressure has an oscillatory behavior in the z-direction, perpendicular to the walls. Our results show that at constant temperature and pore width when the bulk density, and as a result the average density in the nanoslit pore, increases, both of the local and lateral components of pressure tensor increases. Also, at constant bulk density and temperature with increasing the pore width, the depth of oscillations of the local pressures decrease whiles the number of maximum and minimum in those increases. For investigation on the role of attractive intermolecular forces on local pressure tensor, we have also numerically solved these equations for lennard-jones confined fluid. Our results are shown that the attraction contribution of intermolecular interaction to local pressure is negative. As a result the local pressure tensor of LJ con?ned ?uid is lower than those of hard-sphere con?ned ?uid. In the next part, the local normal pressure of confined fluids in nanopores has been predicted within the framework of density functional theory. The Euler- Lagrange equation in statistical mechanical density functional theory is used to obtain the force balance equation which leads to a general equation to predict the local normal pressure. Our results in this part are same as those in the previos part qualitatively. In the final part, free expansion of pure and mixture of hard sphere has been studied using dynamical density functional theory. The results of this part show that an inhomogeneous confined hard sphere fluid between two hard walls free expanded by removing the walls and homogeneous structure will provide.
