Benzene confined in MCM-41 below its melting point : A proton NMR study

Abstract
Benzene confined in MCM-41 (3 nm) was studied by the mean of the line widths, line shapes, T₁ et T₂ nuclear magnetic resonance (NMR) measurements. On the contrary to the bulk, no evidence of a sharp phase transition in the confined system can be obtained from the temperature dependence of the studied parameters. At room temperature, the dynamics of the confined liquid is significantly reduced. At lower temperature, it slows down but is still much faster than the bulk crystal, suggesting the formation of a highly diffusive solid or a highly viscous liquid. Moreover, no obvious distinction between the surface molecules and the molecules at the centre of the pores is obtained.