Spectroscopic study on chemical structure of plasma‐polymerized hexamethyldisiloxane

Abstract

A plasma‐polymerized material was produced from hexamethyldisiloxane vapor by a glow discharge polymerization technique. Spectroscopic interpretation of the chemical structure of the polymerized hexamethyldisiloxane was studied by spectroscopic means such as IR, XPS, and NMR. The plasma polymer was barely soluble in the usual organic solvents, although it contained a small amount of the monomer and its oligomers. The IR spectrum indicated that the polymer consisted of SiCH3, SiO, SiCH2, and SiH groups. The surface of the polymer was found to retain structural units similar to the monomer from the XPS measurement. On the other hand, the 13C and 29Si high‐resolution, solid‐state NMR measurements revealed that the plasma polymer was highly crosslinked with a variety of conformations and a number of O atoms surrounding a Si atom. Results from the XPS and NMR spectra suggested that the bulk of the polymer was more oxidized than the surface layer; Si atom was preferentially oxidized. A hypothetical chemical structure was proposed for the polymerized hexamethyl‐disiloxane.

Investigations on the layer growth of plasma polymerized HMDSO coatings on micro-structured polycarbonate (PC) samples

“…The composition of pp-HMDSO layers as well as of pp-HMDSO/O 2 layers is well-known from other publications (Alexander et al, [13] Wade et al, [14] Tajima et al [15] ). Therefore, this paper focuses on the growth of such layer systems on defined imperfections in the lm scale, which are created by scratching the surface of extruded PC with a triangular diamond lancet or by forming arisen rectangular structures by injection molding of PC.…”

Correlation of water vapor adsorption behavior of wood with surface thermodynamic properties

“…18,19 The treatment was performed in an experimental capacitance coupled rotary reactor equipped with a radio frequency (13.56 MHz) power generator. The sample was loaded into the reaction chamber, and the chamber was evacuated to a base pressure of 0.02 mmHg.…”

Diffusion-controlled size-selective chloride ion sensing in the presence of bromide ion using a thin, nanoporous, plasma-polymerized coating on an Ag/AgCl electrode

“…In plasma polymerization, the structure of the film obtained is not necessarily closely related to that of the original monomer, because the process occurs via random generation of unstable intermediate species in the high-energy plasma [27]. The HMDS PP coating has a variety of network moieties consisting of silicon atoms surrounded by a variable number oxygen atoms and methyl groups (e.g., Si(- 3 , and Si(-O-) 4 ) [28], resulting in highly hydrophobic surfaces [27]. Our group has reported that a PP coating deposited at 150 W plasma power was compact enough to impede molecules with molar mass larger than several tens of g/mol (comparable with chloride ion) [26].…”