Fig. 5. Summary of the PNIPAM phase diagram. State points related to coil and globule conformations are assigned on the basis of the average radius of gyration of the polymer chain, if above or below 1.2 nm, and are shown with asterisks and circles, respectively. To distinguish between globular and hydrated globular states we use the tentative criterion of the number of hydration water molecules being ≳12.5 for the latter. The slope of the boundary line is determined from the fact that hydration tends to increase with increasing temperature at high pressures, but should only be used as a guess, awaiting for experimental confirmation, due to the few state points examined in this region. Coloured areas and phase boundaries are a guide to the eye.