most of the time I use disposable brushes and only use them a couple of times.
I rinse out the brush in Turpin and than with a bit of hand-soap I clean it out and let it dry.
if I go to paint the next day I put my brush in a plastic (bread) bag/foil an put it in the refrigerator over night.
might even work for 2 or 3 days.
If I have a longer project I sometimes keep the brushes in raw linseed oil, (that's how painters preserved their brushes in the old days) works well for a couple of weeks, but not for water based paint.
as I write this, I'm not sure, isn't acrylic always waterbased??