Soft polymerization of hexamethyldisiloxane by coupling pulsed direct-liquid injections with dielectric barrier discharge

This work examines the combination of pulsed direct-liquid injections with dielectric barrier discharge at atmospheric pressure for the deposition of organosilicon coatings using hexamethyldisiloxane (HMDSO) as the precursor and nitrogen as the carrier gas. In such conditions, deposition relies on the charging of micrometer droplets and their transport toward the substrate by the Coulomb force. The thin-film morphology and extent of precursor fragmentation are strongly linked to the amount of energy provided by the filamentary discharge to HMDSO droplets. While cross-linked and smooth coatings were achieved at low energies as in standard gas phase plasma polymers, viscous and droplet-like structured thin films were deposited at higher energies. The latter material is attributed to the soft polymerization of HMDSO droplets related to plasma-droplet interactions.

Automated summary

This study investigates the deposition of organosilicon coatings using pulsed direct-liquid injections combined with dielectric barrier discharge at atmospheric pressure. Hexamethyldisiloxane (HMDSO) is used as the precursor and nitrogen as the carrier gas. The morphology and fragmentation of the thin films depend on the energy provided by the filamentary discharge to the HMDSO droplets. Cross-linked and smooth coatings are achieved at low energies, while viscous and droplet-like structured thin films are deposited at higher energies, attributed to the soft polymerization of HMDSO droplets due to plasma-droplet interactions.