Ansys Employee

Diffusing species will show the cell mean based on the volume (mass or whatever) weighted average and is set via the mixture properties. Cross linking is a chemical effect, so I may mix two low-ish viscosity materials that then react to form the high viscosity near liquid that may then cure to become a solid. 

Which are you after? A non-reacting mixture with properties based on it's component species or a reacting mixture where A+B=C and C's properties are not related to A or B in anything other than mass.