Phase diagram of water confined in MCM-41 up to 700 MPa

On the basis of measurements of NMR signal intensity and T1 and T2* relaxation times as a function of temperature (290 K–170 K) and pressure (0.1 MPa–700 MPa), the p-T phase diagram was made for the sample containing water inside and outside MCM-41 pores of 1.81 nm in radius. The temperature of nucleation of water confined in nanopores under normal pressure was 230 K. With increasing pressure this temperature decreased to 200 K under 300 MPa, but with further increase in pressure it did not change.