Initiated Chemical Vapor Deposition onto Moving Liquid Surfaces*

In this talk, we will demonstrate that initiated chemical vapor deposition (iCVD) can be used to deposit thin functional films onto low vapor pressure liquids such as silicone oils and ionic liquids. The substrate viscosity, surface tension, monomer solubility and process parameters such as deposition time and deposition rate determine the polymer structure on the liquid. The spreading coefficient of the polymer on the liquid surface can be used to predict the thermodynamically preferred polymer morphology. Films, nanoparticles, and gels can be formed. We demonstrate that modifications to the deposition chamber can enable in situ modulation of the liquids in a vacuum allowing polymer deposition on moving liquids. We demonstrate liquid motion in silicone oils of viscosities ranging from 5 cSt to 50 cSt. We study the deposition of fluorinated polymers on the moving liquids and demonstrate that the mechanical response of the polymer films can be tuned by the use of a crosslinker ethylene glycol diacrylate. Our experimental findings allow for further understanding of nucleation and growth mechanisms of polymer films on liquid surfaces by inducing liquid motion and allows us to probe the mechanical strength of thin films.