Structure of films

Measurements of the double-layer capacitance provide valuable insights into adsorption and desorption processes, as well as into the structure of film-modified electrodes (6). 

In the same year, Fulda and Tieke [75] reported on Langmuir films of monodisperse, 0.5-pm spherical polymer particles with hydrophobic polystyrene cores and hydrophilic shells containing polyacrylic acid or polyacrylamide. Measurement of ir-A curves and scanning electron microscopy (SEM) were used to determine the structure of the monolayers. In subsequent work, Fulda et al. [76] studied a variety of particles with different hydrophilic shells for their ability to form Langmuir films. Fulda and Tieke [77] investigated the influence of subphase conditions (pH, ionic strength) on monolayer formation of cationic and anionic particles as well as the structure of films made from bidisperse mixtures of anionic latex particles. 

It should be noted here that the structures of films formed by EC-ALE that have been subsequently annealed have not improved, as indicated by X-ray diffraction (XRD). This confirms that the compounds are formed by electrodeposition, and no annealing step is required. 

The structure of films has been studied by several methods, such as X-ray diffraction, IR spectroscopy and nuclear magnetic resonance (NMR) spectroscopy, although the simplest and least expensive technique is that of optical diffraction measurements. 

Giasson et al. (117) give direct electron microscopy evidence for the helicoidal structure of films of the cellulose acetates and of cellulose regenerated from the GTA films by aqueous ammoniiun hydroxide. 

Pfaff, G. Reynders, P. (1999) Angle dependent optical effects deriving from submicron structures of films and pigments. Chem. Reviews 99 1963-1981... 

Abstract—The structure of films formed by a multicomponent silane primer applied to an aluminum adherend and the interactions of this primer with an amine-cured epoxy adhesive were studied using X-ray photoelectron spectroscopy, reflection-absorption infrared spectroscopy, and attenuated total reflectance infrared spectroscopy. The failure in joints prepared from primed adherends occurred extremely close to the adherend surface in a region that contained much interpenetrated primer and epoxy. IR spectra showed evidence of oxidation in the primer. Fracture occurred in a region of interpenetrated primer and adhesive with higher than normal crosslink density. The primer films have a stratified structure that is retained even after curing of the adhesive. 

This work discusses the structure of films formed by a multicomponent silane primer as applied to an aluminum oxide surface as well as the interactions of this primer with the adhesive and oxide to form an interphase region with a distinct composition and properties. The mecanical properties and durability of adhesive joints prepared using this primer system have yet to be evaluated. 

This chapter concerns composite films prepared by physical vapor deposition (PVD) method. These films consist of dielectric matrix containing metal or semiconductor (M/SC) nanoparticles. The structure of films is considered depending on their formation by deposition of M/SC onto dielectric substrates as well as by layer-by-layer or simultaneous deposition of M/SC and dielectric vapor. Data on mean size, size distribution, and arrangement of M/SC nanoparticles in so obtained different composite films are given and discussed in relation to M/SC nature and matrix properties. Some models of nucleation and growth of M/SC nanoparticles by the diffusion of M/SC atoms/molecules over a surface or in volume of dielectric matrix are proposed and analyzed in connection with experimental data. 

Keywords structure of films, films of zirconia-based solid electrolytes, ion plasma sputtering, scanning electron microscope, transmission electron microscopy. 

The structure of films of zirconia-based solid electrolytes was analyzed in a scanning electron microscope. It was found that both one- and multilayer films (Fig. la, lb) of zirconia, which was stabilized to its cubic modification, up to 10 pm thick had a columnar structure, that is, consisted of mutually adjoining crystallites, which generally were oriented perpendicularly to the film surface. The observed deviation of the crystallites from the normal direction to the film plane was not over 15° and was explained by the mutual misorientation of the target and the substrate. 

Film balance structure of films, alcohols, amides and acids. 

It had previously been reported that the structure of electroless NiP alloy films containing less than 15 at% phosphorus is crystalline, while the structure of films containing more than 15 at% is amorphous [26]. The structure of NiWP and NiMoP depends on the phosphorus content. NiP, NiWP, and NiReP, for instance, become amorphous if their phosphorus content exceeds a certain value. NiReP and NiWP, as shown in Tkble 6 and 7, are amorphous over the entire range of compositions. The structure of NiReP film plated from a bath containing 0.03 mol dm of NH4Re04 in particular is peculiarly amorphous, in spite of the fact that its phosphorus content is only 5 at%. This film contains as much as 44 at% of rhenium. 

Preliminary results of Monte Carlo simulation [183] have also demonstrated the usefulness of the bond - orientational order parameters in determining the inner structure of films adsorbed on the (100) face of an fee crystal. 

A great deal of work has been done to characterize the structure of films cast from chemically prepared polythiophenes.96 Most of this work has been conducted on undoped PTh s because of their importance in electronic devices, such as thin-film transistors and photovoltaics. Depending on composition and processing conditions, the crystallinity can be as high as 30% in polythiophenes.97 A layered structure is usually formed in PTh crystals between extended chains held together by ir-slacking, with additional structural order introduced by alkyl side-chain interactions in functionalized PTh s.98 Chemically synthesized PTh powders exhibit a... 

Figure 7. Schematic of the structures of films of /3-casein and lysozyme and mixed lipid-protein monolayers...

The theoretical predictions or experimental determinations of the composition, thickness, and structure of films responsible for passivity are difficult. The problem of prediction is complicated by many factors, including knowledge of the composition of the solution at the material interface, knowledge of the effects of potentials differing significantly... 

In siunmary, a vast number of materials has been used to form LB films. However, in the majority of cases an effort to characterize the film structure or even to show that a regular layer structure has been achieved is lacking. Work on the structure of films of disc-like molecules such as porphyrins and phthalocyanines is especially limited. Some references can be found in [29]. 

A revised picture is needed to describe the structure of films composed of coadsorbed polar solute molecules and nonpolar solvent molecules. The close-packed model of Reis implies that the coadsorbed solvent should be relatively tightly bound. That this is apparently not the case is suggested by the ease with which the n-octadecane was removed from all the films. The data show that n-octadecane is more firmly attached to the surfaces on which stearic acid is adsorbed than to surfaces on which no acid is adsorbed. This means that the coadsorbed n-octadecane found is not present in the film as relatively large aggregates of randomly oriented solvent molecules on the surface. These aggregates, if they exist on the surface initially, should have been removed by the 5-second rinse. This is based on the fact that solvent was removed from the silver mirrors which had been immersed in pure n-octadecane containing no stearic acid. 

In order to explain a particular industry s market structure, economists in the field of industrial organization traditionally examine the cost structure of films. For major gas pipelines this style of economic analysis does not go far enough. The most basic economic analysis would appear to paint pipelines as almost classic natural monopolies, but the pipeline business is much more complex and difficult to categorize. To most policy makers, the structure of pipeline markets, for both oil and gas, remains something of a mystery. 

---