The state of water and several transitions were examined in the systemsn-decanephosphonic acid (DPA)—water and the sodium salts of DPA—water. Temperature — composition phase diagrams are reported.
The results show that several liquid crystalline phases plus isotropic liquid, and two solid phases (a waxy solid phase and
a crystalline phase) are formed. Several types of water were detected: bulk-like water, interfacial water and hydration water.