Abstract
Normal alkanes of carbon number n>14 exhibit surface crystallization at their liquid-vapor interface. This has been investigated with x-ray reflectivity, grazing incidence scattering and surface tension measurements. The structure and thermodynamics of the surface layer is consistent with a monolayer of the bulk rotator phase occurring at the surface above the bulk melting temperature. On the other hand, thin films of alkanes on SiO2, exhibit a reduction of the melting temperature. The surface crystalline phase is observed for carbon number n>14. The vanishing of surface phase for small n may be due to a transition from surface freezing to surface melting behavior. These measurements can yield the relative surface energies of the various phases.
Original language | English |
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Pages (from-to) | 15-26 |
Number of pages | 12 |
Journal | Materials Research Society Symposium - Proceedings |
Volume | 366 |
State | Published - 1995 |
Externally published | Yes |
Event | Proceedings of the 1994 MRS Fall Meeting - Boston, MA, USA Duration: 28 Nov 1994 → 1 Dec 1994 |