If the particles you want to model are inert, the only material property required for particles is the density. Multicomponent particles can also be created: one application of these is to model liquid and oil evaporation. For details, see:

Another is for modeling coal combustion. For details, see Multiphase Reactions and Combustion.

If modeling heat and mass transfer, the additional material properties that must be specified are specific heat capacity and reference enthalpy (although reference enthalpy is not required if latent heat is selected for the heat release method). For details, see Heat Release/Heat Release Distribution.

You can create new materials from the Material details view in CFX-Pre. For details, see Materials and Reactions in the CFX-Pre User's Guide. Each material that you create will be available for selection from Fluid and Particles Definitions... on the Basic Settings tab when creating new domains. For details, see Basic Settings Tab in the CFX-Pre User's Guide.