Atmospheric‐pressure plasma‐enhanced chemical vapor deposition of nanocomposite thin films from ethyl lactate and silica nanoparticles.

Nanocomposite coatings are made by atmospheric‐pressure plasma‐enhanced chemical vapor deposition from ethyl lactate (EL) and silica nanoparticles (NPs) in a dielectric barrier discharge (DBD) using frequency‐shift keying (FSK) to alternate between 1‐ and 15‐kHz voltages. In situ plasma Fourier‐transform infrared spectroscopy (FTIR) and thin film FTIR, scanning electron microscopy, atomic force microscopy, and profilometry show that (i) 1 kHz DBD mainly deposits NPs, 15 kHz only polymerizes EL; (ii) the EL polymerization rate is the same in FSK and continuous modes; (iii) despite the 50/50 contribution of both frequencies, the NP deposit is three times faster in FSK mode than in 1 kHz DBD and compared with 1 and 15 kHz coatings, in the nanocomposite, NP Si–O–Si and EL C═O bonds per unit length are equal to 68% and 34%, respectively. In situ FTIR detects SiO2 NPs, their functionalization, and the formation of CO2. [ABSTRACT FROM AUTHOR]