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. Understanding the structure formation during the APP jet polymerization of HMDSO is important for the design of coatings with specific properties. This work analyses in the chemical structures of single tracks of plasma polymerized HMDSO and discuss the influence of several process parameters on the structure of the coating. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.