Anisotropic polymerization of a long-chain diacetylene derivative Langmuir-Blodgett film on a step-bunched SiO2/Si surface.
Alternating facet/terrace nanostructures were fabricated on a SiO2 surface by step-bunching and thermal oxidation of a vicinal Si(111) substrate, and their influence upon the polymerization direction of a long-chain diacetylene derivative monolayer film was investigated by angle-dependent polarized near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. It was found that the peak intensity of the C 1s-pi transition was stronger when the electric vector plane of the incident X-ray was parallel to the direction of the periodic facet/terrace structures rather than perpendicular to them. On the contrary, a polymer film fabricated on a flat SiO2 surface showed no in-plane anisotropy of the peak intensity. These results indicate that the diacetylene groups in the diacetylene derivative monolayer are preferentially photopolymerized in the direction not across but along the periodic one-dimensional structures on the step-bunched and thermally oxidized SiO2/Si(111) surface.
Onoki
Ryo
R
Department of Chemistry, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan.
Ueno
Keiji
K
Nakahara
Hiroo
H
Yoshikawa
Genki
G
Ikeda
Susumu
S
Entani
Shiro
S
Miyadera
Tetsuhiko
T
Nakai
Ikuyo
I
Kondoh
Hiroshi
H
Ohta
Toshiaki
T
Kiguchi
Manabu
M
Saiki
Koichiro
K