Molecular Aggregation State of n-Octadecyltrichlorosilane Monolayers Prepared by the Langmuir and Chemisorption Methods

Abstract

A comparative study in molecular arrangements of the n-octadecyltrichlorosilane (OTS) monolayer prepared by the Langmuir method and the chemisorption methods were carried out on the basis of grazing incidence X-ray diffraction (GIXD) and X-ray reflectivity (XR) measurements. The OTS molecules in the Langmuir OTS monolayer uniformly tilt ca. 8-10°to the surface normal and packed in a hexagonal lattice with the (10) spacing of 0.412 nm. On the other hand, the OTS molecules in the chemisorbed OTS monolayer tilt ca. 15-17°to the surface normal and also crystallite orient randomly in the two-dimensional plane. The average magnitude of the (10) spacing of the chemisorbed OTS monolayer was ca. 0.417 nm. Direct evidence that the packing density of the Langmuir OTS monolayer was higher than that of the chemisorbed OTS monolayer was obtained by GIXD and XR measurements for the first time.

Engineering Silicon Oxide Surfaces Using Self‐Assembled Monolayers

“…Kajiyama and co-workers compared OTS monolayers prepared by the Langmuir-Blodgett method and the chemisorption method, [48] and found that OTS molecules in the Langmuir monolayer were less tilted (ca. than in the chemisorbed layers .…”

Gestaltung der Siliciumoxidoberfläche durch selbstorganisierte Monoschichten

“…Kajiyama et al verglichen Monoschichten, die durch die Langmuir-Blodgett-Methode und durch Chemisorption hergestellt wurden, [48] und fanden, dass OTS-Moleküle der Langmuir-Monoschicht weniger geneigt waren (ca. 8-108) als jene in chemisorbierten Schichten [52] und Hoffmann et al [20] [14,17] voraus, dass Monoschichten über Inseln entstehen, während andere die Meinung vertraten, dass stattdessen zunächst ungeordnete, homogene, unvollständige Monoschichten gebildet werden.…”

Characteristics of monolayer behavior and multilayer film structures of comb polymers having different kinds of fluorocarbon side-chains

“…The hydrogen bonding in the films was examined by measuring the change of IR spectra (JASCO FT-IR 660Plus, in vacuum). The two-dimensional lattice packing of the fluorocarbon side-chains for the Z-type films of the comb polymers was obtained by in-plane X-ray diffraction using an X-ray diffractometer with special geometrical arrangements [17] (Bruker AXS, MXP-BX, CuK α radiation, 40 kV, 40 mA) equipped with a parabolic graded multilayer mirror, applying a grazed incident angle at 0.2 • and slow scanning at 0.05 • /150 min (multilayer: 0.05 • /20 min scan rate). NEXAFS spectra were measured on the BL-7A and 11A soft X-ray beamlines at the Photon Factory in the National Laboratory for high-energy accelerator research organization (KEK-PF) with synchrotron radiation from a bendingmagnet source.…”