S. Stapf et R. Kimmich, TRANSLATIONAL MOBILITY IN SURFACE-INDUCED LIQUID LAYERS INVESTIGATED BY NMR DIFFUSOMETRY, Chemical physics letters, 275(3-4), 1997, pp. 261-268
The self-diffusion properties of plastic succinonitrile and cyclohexan
e confined in nanoporous glass were investigated by means of NMR field
-gradient diffusometry. The results are compared to diffusion measurem
ents in the bulk as well as to the relaxational behaviour of other con
fined plastically crystalline substances. For all adsorbates, bed low
the freezing point a thin layer near the glass surface is found to ret
ain a high translational mobility as compared to the plastic phase in
the center of the pore. The behaviour of the unfrozen layer can be des
cribed by liquid like diffusion inside a network of channels with temp
erature-dependent width assuming fast molecular exchange with the plas
tic phase. (C) 1997 Elsevier Science B.V.