Partially crystalline TiO 2 was deposited on polystyrene substrates by liquid phase deposition. Both nucleation and adhesion depend on the respective pretreatment of the polymer. Coherent films are formed on untreated substrates and surfaces hydroxylated by aqueous sodium peroxodisulfate solution, but satisfactory film adhesion is only observed on the modified surface. The formation of continuous films is not observed on polystyrene etched by H 2 SO 4 /SO 3 where material deposition was only initiated at few nucleation sites. The TiO 2 precipitation was characterized as a function of time and compared to previous results on wet chemically grafted PS. A film formation mechanism is proposed which can account for the textured constitution of TiO 2 observed by X-ray diffraction experiments.
Polystyrene (PS) substrates were functionalized by wet chemical grafting with 2-acrylamido-2-methylpropane-1sulfonic acid (AMPS). Subsequently, TiO 2 thin films were prepared by liquid phase deposition (LPD) with an average growth rate of 85 nm h 21 ; a maximum thickness of 750 nm was observed in our experiments. The crystalline fraction of the precipitated material was estimated to be 58% by X-ray powder-diffraction. Significantly improved film adhesion was achieved on grafted substrates, as compared to non-functionalized polymers, due to the formation of a thin, coherent primer layer in the early stages of mineralization.
Summary: Poly(propylene) surfaces were modified by polymerization of acrylic acid using an RF plasma technique. Whereas a stable and reproducible hydrophilicity is obtained even after short treatment times, the thickness of the deposited layer, and thus the concentration of COOH functional groups per substrate surface area, increases with plasma exposure time. The modified‐poly(propylene) samples were exposed to aqueous solutions supersaturated with respect to CaCO3. Even though the polymer surfaces show a significant affinity for the adsorption of Ca2+ ions, the density of nucleation sites for calcite is reduced in comparison to untreated poly(propylene). This result can be explained by the special conditions in porous (“gelatinous”) growth media and high disorder provided by the plasma‐polymerized layers.AFM surface profile of a poly(propylene) surface (*) and film segments of plasma‐polymerized acrylic acid (**).imageAFM surface profile of a poly(propylene) surface (*) and film segments of plasma‐polymerized acrylic acid (**).
In this study, the mechanical properties of transparent conducting oxide (TCO), aluminium doped zinc oxide (ZnO:Al) and fluorine doped tin oxide (SnO 2 :F) thin films on glass substrates were investigated. The micromechanical properties as elastic and permanent deformation, microtribological properties and scratch resistance were measured with high local resolution to assess the film properties. The micro-structure-analysis ® method (MISTAN ® ) was used to characterize those properties.
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