The adhesion of paint systems to stainless steel substrates can be markedly improved by a pretreatment using organofunctional silanes. The paint-metal interface thus obtained can be made more resistant to corrosive attack by adding a silane crosslinker to the hydrolyzed silane solution. The films formed on the metal surface were characterized by Time-of-Flight Secondary Ion Mass Spectrometry (TOFSIMS).

Adsorbed surfactant bilayers on silica are proposed as the reaction site for the formation of ultrathin polystyrene films. Results from the polymerization of styrene in cetyl trimethyl ammonium bromide bilayers show effective conversion of adsolubilized monomer to polymer. The process has been demonstrated for a variety of precipitated silica substrates and for two types of initiation schemes. The polymer formed has been extracted and characterized using PA-FTIR, NMR, UV, and GPC. The molecular weight of polymer formed has also been investigated with respect to polymerization time.

The covalent attachment of polymers such as polystyrene, polymethylmethacrylate and polyacrylonitrile to microparticulate silica and to silicon wafers through immobilized radical chain initiators (especially azocompounds) is described. The initiator is bonded to the surface using α,ω-substituted silanes, which have only one functional group at the silane head group.

Up to 10 g of polymer per g of silica could be covalently bonded to the surface. The attached monolayers were characterized using diffuse reflectance FTIR spectroscopy, XPS and elemental analysis. After the cleaving off of the attached layers molecular weights up to 300.000 g/mol were measured. Transmission electron micrographs generated with an element specific imaging technique (ESI) clearly show a continuous, about 10 nm thick, polymer layer around the silica particles.

We have studied the effect of oxygen ion bombardment of glassy carbon at room temperature, using a composite bi-energy beam of 3.2 and 3.1 MeV ions. Carbon specimens were prepared in-house by pyrolysis of phenolic resin at 1000° C. Raman microprobe spectra of the surface and implanted volume before and after irradiation showed that the implanted oxygen ions had disrupted translational symmetry at the surface and caused maximum damage in the carbon 3.5 μm below the surface. By analogy to the “activation” of charcoals1 we conclude that pores are opened up by preferential attack of strained carbon sites.

Plasma polymerization of thin, fluorocarbon films onto glass, low carbon steel, and aluminium foil substrates using a hexafluoroethane (C2F6) glow discharge in a parallel plate, rf-sputter system was studied. Continuous, 100 nm thick fluoropolymer films were obtained when a graphite sputter target was used as the cathode material. Depositions conducted without the use of a consumable cathode produce continuous but thin (<10 nm) films of fluorocarbon material. Analysis of the plasma by optical emission spectroscopy determined that the dominant species in the discharge was CF2 for both target configurations. An increase in the intensity of specific CF2 transitions was observed when the graphite target was used. Characterization of the deposited films by X-ray photoelectron spectroscopy of the C 1s and F 1s photoelectrons was used to determine the atomic F/C ratio and distribution of CF3, CF2, CF, C-CF, and C binding states. Films fabricated with the graphite target had a lower F/C ratio than depositions made without a consumable target. However, the distribution of binding states and the F/C ratio in the fluoropolymer was dependent on the substrate material. The results of the study indicate that the fluoropolymer film composition was significantly influenced by the underlying substrate material.

The interface shear properties of thin bisphenol-A-poly(carbonate) films are measured and interpreted in terms of the effects of the morphology induced by solvent plasticisation. The variations in the interface rheology are discussed in terms of the Eyring stress modified thermally activated flow model. The changes in the molecular architecture, induced by plasticisation, are also examined using vibrational spectroscopy. A correlation is made between the proposed mechanism for microshear and the conveyed morphological properties of the polymer film at the molecular level.

Supported bilayer lipid membrane (s-BLM) is a new type of self-assembled membranes. In this paper, the s-BiMs were formed on the tips of the freshly cut Teflon-coated stainless steel wires. The sensitivity of s-Bills to Haca was studied by current and potential measurements. We also investigated the effects of TCNQ and DP-TrF modifiers on the H2O2 response of the s-BLM systems. It was found that DP-TTF molecules can improve the stability of the s-BLM and its sensitivity range to H2O2. Further, the cyclic voltammetric behaviors of the s-Bill systems were studied as a function of H2O2 concentration.

The molecular structure of interphases formed between thin films of the polyamic acid of pyromellitic dianhydride (PMDA) and oxydianiline (ODA) and silver substrates that were pretreated with m-aminothiophenol (m-ATP) was determined using surface enhanced Raman scattering (SERS) and X-ray photoelectron spectroscopy (XPS). It was found that m-ATP adsorbed dissociatively onto silver substrates through the thiol groups. When thin films of the polyamic acid of PMDA/ODA were spin-coated onto the silver substrates treated with m-ATP, an interphase that was only a few angstroms in thickness was formed in which acid groups of the polyamic acid and amino groups of the m-ATP combined to form ammonium carboxylate species. The bulk of the polyamic acid films was cured to polyimide by immersion in mixtures of acetic anhydride and pyridine or triethylamine but ammonium carboxylate species inhibited curing in the interphase.

The interfacial interaction of a thermoplastic copolymer ethylene-maleic anhydride with stainless steel has been studied by infrared spectroscopie techniques (FTIR) in order to improve the durability of steel/polymer association, by modifying formulation of polymer or surface treatment of stainless steel.

In order to be successful, an analytical methodology has been established. Interfacial chemical actions of maleic anhydride with stainless steel are simulated through thin layer of succinic anhydride on polished metal surface. FTIR spectroscopie (grazing angle) permit a direct access ot interphase for identifying new bounds between organic and metallic compounds.

Interaction of succinic anhydride with the polar OH groups of the oxidized metal surface follawed a reactional mechanism which can be described by two steps:

- opening of the anhydrid ring for reacting with adsorbed water and formation of acid group (-COOH),

- reaction of acid group with hydroxylic fraction of metal surface and formation of carboxylate anion (-COO-) groups.

In this paper we illustrate the use of Ultra Soft X-ray Absorption Spectroscopy (USXAS) for the characterization of polymeric materials by highlighting three novel applications of the technique. The surface sensitivity of electron yield (3 nm) and the bulk information available from fluorescence yield USXAS (200 nm) provide unique information on the chemistry of polymer surfaces and interfaces. USXAS is sensitive to both concentration and orientation of functional groups in polymers. The systems highlighted here include the characterization of flame treated model acrylic automotive coatings, ultra-low surface energy crosslinked fluorocarbon films, and spin cast polystyrene films. The chemical and surface sensitivity of the technique are emphasized by the ability of USXAS to detect an increase in the trigonally coordinated carbon at the surface after treatment with a reducing flame. The sensitivity to functional group orientation at the surface is demonstrated by the characterization of the crosslinked flurocarbon polymer films. The results show that the pendant fluoroalkyl moieties of these polymers are strongly oriented perpendicular to the film surface. Spin coated polystyrene films were characterized as a functionv of molecular weight, film thickness and casting solvent. The pendant phenyl groups were found to be preferentially oriented towards the normal to the surface plane, independent of casting solvent, molecular weight, and film thickness

Polyphenylene oxide (PPO) films have been investigated as protective coatings and as selective inhibitors to permeants.1,2,3 These films have been shown to be passivating materials and therefore are potentially interesting for a variety of applications. It is important for further applications to be able to measure the thickness of thin films by nondestructive techniques, which is the subject of this report. In this study PPO films of various thicknesses were electrodeposited on highly oriented pyrolytic graphite (HOPG) electrodes and examined by spectroscopic ellipsometry (SE) and atomic force microscopy (AFM). These techniques are combined to yield the thickness of the polymer film and the optical properties of the HOPG substrate and the PPO overlayer in the visible and near ultraviolet spectral region.

The adsorption behavior of model associative polymers in aqueous titanium dioxide (TiO2) and polystyrene latex (PS) particle dispersions has been studied using liquid-state Nuclear Magnetic Resonance (NMR) and a modified serum replacement technique (SRT). The structure of the associative polymer is a linear, water soluble, A-B-A block copolymer with a polyethylene oxide backbone and hydroxyl (H) or hexadecyl (C16H33) endgroups.

Absolute intensity NMR measurements allow the determination of the adsorbed polymer configuration at the solid-solution interface and adsorption isotherms for comparison to the SRT results. Both the SRT and NMR results demonstrate that the adsorption/desorption of the C16 and H polymers is strongly affected by the substrate. For the polymer/PS particle systems, there is good agreement in complete surface saturation values for the SRT and NMR methods. In the polymer/TiO2 systems, the H polymer plateau as determined by NMR differs slightly from that determined by SRT. For the C16/TiO2 system the interpretation is less straightforward. Either the NMR saturation value is at least double that of the SRT value or the C16 and H polymers have very similar isotherms by NMR. This would suggest that on TiO2 the effect of the hydrophobe is minimal. For all the polymers the polymer/particle interaction on PS is strong and desorption is difficult while on TiO2 it is weak and completely reversible. A pancake-to-brush conformation change on the PS surface is evident for the C16 polymers and probably for the H polymer as well. The H polymer seems to form a multi-layered structure on PS from the NMR and laser light scattering results. The contribution of the hydrophobe and the effect of increasing the backbone molecular weight are clearly illustrated.