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 SiO(2)NPs, their functionalization, and the formation of CO2.

Automated summary

Nanocomposite coatings were fabricated using ethyl lactate and silica nanoparticles through atmospheric-pressure plasma-enhanced chemical vapor deposition, with frequency-shift keying applied to alternate deposition between 1 kHz and 15 kHz voltages. The study revealed that deposition of nanoparticles mainly occurred at 1 kHz, while polymerization of ethyl lactate was predominant at 15 kHz. The nanocomposite coatings showed a higher deposition rate of nanoparticles in FSK mode compared to 1 kHz DBD, with different proportions of Si-O-Si and C-O bonds in the coatings. Additionally, in situ FTIR analysis detected the presence of SiO(2)NPs and the formation of CO2 during the process.