8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P7.96Thu 811:10-14:00Rotational dynamics of the Tetrahydrofuran -waterclusters in hydrophobic nanoporesJamoliddin Razzokov, 1 Sardor Ashirmatov, 1 and Shavkat Mamatkulov 11 Heat Physics Department, Academy of Sciences of Uzbekistan, Chilanzar C, Katartal str,28, 700135, Tashkent, UzbekistanFree energy of hydration and rotational dynamics of tetrahydrofuran (THF)-water clusters confinedbetween graphene layers were studied using molecular dynamics method. The hydration freeenergy of THF in various pressures and over the temperature range 230-300 K were calculated. Atthe temperature range 230-235 K, and 120 bar pressure, the free energy change passes the minimalwhich indicates liquid-solid phase transition and formation of a comparatively stable clathratehydrate state. Hydration free energy of the THF confined between graphene layer essentially largecomparing free energy value of THF in bulk water. Rotational spectra of the THF were calculateddepending on temperature and pressure. Rotational correlation function of THF molecules havejump at T=230 K which can be explained by disruption of hydrogen bonding between THF andwater molecules and relatively free state of the guest molecule. An analysis of the radial distributionfunction and the coordination number of the THF molecule showed that, at 240-257 K, aclathrate hydrate of THF with the structure close to clathrate sII was predominantly formed. Thework has been supported by Grant FA-F082 Academy of Sciences of Uzbekistan.96