Track by Track: The Structure of Single Tracks of Atmospheric Pressure Plasma Polymerized Hexamethyl Disiloxane (HMDSO) Analyzed by Infrared Microscopy

Abstract

A comprehensive infrared microscopic study of single tracks of atmospheric pressure plasma polymerised HMDSO is presented. The effects of different process parameters, i.e. the process gas, the nozzle setting (distance between discharge chamber and injection point of the monomer gas), and the nozzle speed, are investigated. It is shown that the chemical structure of singles tracks is not homogenous along the deposit. An increase of the oxygen content in the process gas or an increase of the excitation energy transferred to the monomer gas increase the relative content of SiOCH3 and SiOH units within the bulk polymer network. The deposition of superposed tracks is studied as well and it is revealed that the structure of the coating is changed compared to the first track.

Deposition of Water-Stable Coatings Containing Carboxylic Acid Groups by Atmospheric Pressure Cold Plasma Jet

“…Considering the thin film deposited at AA and ethylene concentrations of 19 and 200 ppm, respectively, Figure a shows that the percentage of carboxylic groups in the C1s XPS spectra does not change significantly as a function of the position across the deposited spot before and after immersion in water. The thickness profile in Figure b is symmetric, shows a maximum at the center of the spot (0 mm position) and does not change appreciably after water soaking. The thickness loss after 72 h of water soaking was lower than 7% and, in particular, was negligible for AA concentrations up to 19 ppm, as also confirmed by the thickness profile in Figure b and the cross‐sectional SEM images in Figure c.…”

Characterization of the deposition behavior and changes in bonding structures of hexamethyldisiloxane and decamethylcyclopentasiloxane atmospheric plasma‐deposited films*

“…Several reviews have been published on various types of atmospheric plasma processes . Numerous studies using various atmospheric plasma techniques have been reported for PECVD of organosilicon materials …”

“…As a relatively simple and inexpensive organosilicon, hexamethyldisiloxane (HMDSO) is a widely studied precursor for PECVD processes . However, HMDSO is highly flammable with a rating of 4 for flammability and has a German water rating of 3 (severe hazard to water).…”

Influence of the nozzle head geometry on the energy flux of an atmospheric pressure plasma jet

“…For both nozzle heads, the fraction reaching the substrate of the probe originates preferably from the center of the flow where the gas has presumably the highest temperature (ref. [12,[30][31][32]). The relaxation volume of nozzle head B results in an increased time for collisions and, thereby, extended thermalization of the gas due to the added distance between the excitation volume and the probe.…”