Phase transition of n-alkane layers adsorbed on mica.
Thin (thickness h approximately 3 nm) films of n-octadecane and n-hexadecane adsorbed on mica surfaces from vapor close to their bulk melting points (T(m)) have been studied in a surface force apparatus. Using data on the growth rate of capillary condensates between the mica surfaces in contact and measurements of h, we have identified a transition in the structure of the adsorbed films a few degrees above T(m). As T decreases the alkane layers appear to undergo a transition to a more ordered structure, akin to the postulated "surface freezing" of long-chain liquid n-alkanes.
Maeda
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N
Department of Applied Mathematics, Research School of Physical Sciences, Australian National University, Canberra ACT 0200, Australia.
Kohonen
M M
MM
Christenson
H K
HK