화학공학소재연구정보센터
Langmuir, Vol.28, No.34, 12493-12501, 2012
Effect of Substrate Temperature on the Epitaxial Growth of Oriented n-Alkane Thin Films on Graphite
A complex orientational morphology is observed when n-alkane thin films are vapor deposited on highly oriented pyrolytic graphite surfaces Substrate temperature can be used to tune the orientation and morphology of n-alkane thin films. The molecular orientation changes from lateral to normal to the surface when the substrate temperature is raised sufficiently. Under specific substrate temperature conditions, the n-alkane molecules are aligned in the plane of the sample surface, in directions reflecting the 6-fold symmetry of the graphite substrate. A series of different morphologies, from uniform thin films to oriented bars, are observed as a function of chain length and substrate temperature. The systematic evolution of these oriented morphologies is mapped as a function of deposition conditions, and the kinetic and thermodynamic factors that govern the formation of different in plane and normal domains are considered.