The phase diagram of ATP was prepared according to the
“cloud point” method [29]. Simply, a concentrated aqueous solution
of polymer or ionic liquids was added dropwise into an
aqueous solution containing preweighted Na2HPO4. The turbidity
of mixture was inspected with UV (Lambda bio 40,
PerkinElmer Company) at 600 nm until full phase separation
happened. The concentration of polymer or ionic liquids was
recorded. The procedure was repeated until a sufficient number
of points for the construction of the binodal curve were
obtained.