modeling 0.1 M glucose (ph 7.0) and PBS buffer (ph 7 or 5)

Hi everyone

does someone of you know how to model in Comsol 5.2 the properties of

* glucose media, 0.1 M, ph 7
* PBS buffer (oxygen saturated), at ph 7 (and then 5)

I need those to see if mixing occurs or not in a double Y microfluidics channel (attached in figure).
Thanks in advance..