Hydrophobic hydration of argon at high temperatures

Neutron diffraction experiments were carried out on a mixture of argon in w ater under a pressure of 300 bar and a temperature of 318 degreesC. The dat a were analyzed by standard procedures and showed that the argon atom is hy drated with 9 (1) water molecules, a substantial reduction from the value o f 16 (2) at ambient temperature and a pressure of 250 bar. This result is i n excellent agreement with the computer simulation study of Guissani and Gu illot, which was carried out on an argon/water mixture at high temperatures and pressures. (C) 2001 American Institute of Physics.