Paper PS+AS+NS+SS-ThM10
Growth of Nanocomposites on Heat-Sensitive Polymers using Cold, Dielectric Barrier Discharges at Atmospheric Pressure

Thursday, October 31, 2013, 11:00 am, Room 102 B

Cold, atmospheric-pressure plasmas have already demonstrated their potential for homogeneous thin film deposition in polymers functionalization. In order to achieve multifunctional properties, a new challenge is the plasma-assisted deposition of nanocomposite coatings. This contribution is focused on the growth of nanocomposites based on TiO₂ nanoparticles embedded in a silica-like matrix with the objective of synthesizing barrier layers with improved resistance to UV irradiation. Experiments were carried out in a parallel plate dielectric barrier discharge with the substrate placed on the bottom electrode. The gas mixture is composed of either N₂ or He as the carrier gas, a mixture of hexamethyldisiloxane, and either nitrous oxide (for experiments in N₂) or O₂ (for experiments in He) for the growth of the SiO₂ matrix, and TiO₂ nanoparticles which are introduced by nebulizing stable colloidal solutions. Preliminary results show that TiO₂ nanoparticles can successfully be incorporated in the film. In addition, as in low-pressure plasma conditions, electrostatic forces were found to play a very important role on the transport of nanoparticles in the discharge. As a result, an appropriate tuning of the applied voltage waveform (shape, amplitude and frequency) was found to directly impact the spatial distribution of nanoparticles in the film.