  The effective pair potentials between different kinds of dendrimers in
solution can be well approximated by appropriate Gaussian functions. We find
that in binary dendrimer mixtures the range and strength of the effective
interactions depend strongly upon the specific dendrimer architecture. We
consider two different types of dendrimer mixtures, employing the Gaussian
effective pair potentials, to determine the bulk fluid structure and phase
behavior. Using a simple mean field density functional theory (DFT) we find
good agreement between theory and simulation results for the bulk fluid
structure. Depending on the mixture, we find bulk fluid-fluid phase separation
(macro-phase separation) or micro-phase separation, i.e., a transition to a
state characterized by undamped periodic concentration fluctuations. We also
determine the inhomogeneous fluid structure for confinement in spherical
cavities. Again, we find good agreement between the DFT and simulation results.
For the dendrimer mixture exhibiting micro-phase separation, we observe rather
striking pattern formation under confinement.
