The effect of film thickness

H.M. Princen, M.P Aronson, and J.C. Moser Highly Concentrated Emulsions. II Real Systems. The Effect of Film Thickness and Contact Angle on the Volume Fraction in Creamed Emulsions. J. CoUoid Interface Sci. 75, 246 (1980). 

The use of FTIR to study reaction kinetics and chemical equilibria is based on the disappearance of a v(COO—) vibrational mode of the deprotonated fatty acid in concurrence with the appearance of the v(C=0) mode of the protonated FA. This type of data has been used to support reaction times of a few minutes to several hours or even days. Also, the extent of the reaction has been reported to be stoichiometric (22,23,39,43,47,53), based on the complete disappearance of the v(COO—) vibrational mode, whereas other studies indicate less than 100% conversion (Fig. 3.5.8) of the carboxylate to the protonated form (48,61,66,70). The effect of film structure on reaction rate has been discussed (61,66,70) however, discrepancies of the extent of the reaction of M-FA with H2S have not been previously addressed. FTIR spectroscopy has also been used to determine the effect of film thickness on reaction rate. For example, for 11-, 21-, and 31-layer CdSt films deposited at 37.5 mN in-1, reactions with H2S were found to slop at 42, 78, and 140 h, respectively (66). 

The effect of film thickness was very evident for films deposited from baths based on A/,A-dimethylselenourea and complexed with both ammonia and either... 

In this paper we report on TOFSIMS and XPS analyses of thick and thin films of SAAPS on zinc in order to demonstrate the effect of film thickness. We also present some TOFSIMS results obtained with films of y-APS on mild steel in which the effects of the cleaning process of the substrate and the pH of the silane solution are demonstrated. 

The excellent stability and reproducibility of these modified poly(aniline) electrodes for NADH oxidation allows detailed kinetic studies of the system to be completed. To determine the mechanism of NADH oxidation the effects of film thickness, electrode potential, rotation rate and NAD concentration have been investigated. 

First, the effect of film thickness on the amperometric response was studied. The effect of film thickness has been assessed for eight different film thicknesses at four different NADH concentrations. For thin films, Fig. 2.18 shows that the response increases with film thickness reaching a... 

The Effect of Film Thickness on Lamellar Growth Rate and Morphology... 

The initial thickness of most molybdenum disulphide coatings has an important influence on the performance and life of the coating . The special case of sputtered films is considered in Chapter 10, and there is little information about thickness effects for in situ or transfer films. Many workers have investigated the effect of film thickness on bonded films, but, as was pointed out earlier, much of this work appears confusing, and sometimes contradictory, because of failure to understand and analyse the effects of running-in or burnishing on the consolidation and resulting structure of the films. 

Further work was carried out with 3% - 5% of co-sputtered nickel to evaluate the effects of film thickness and test speed and load. He found that the life of a co-sputtered film increased almost linearly with coating thickness, while that of a conventional film reached a maximum at a thickness of about 4000 nm (40,000A), These are far thicker than coatings described by other authors. A comparison of life... 

Bahun, C.J. and Jones, J.R., Influence of Load, Speed and Coating Thickness on the Wear Life of a Bonded Solid Lubricant, Lubric. Eng., 25, 351, (1969). Hopkins, V., Discussion, p. 6, on Rabinowicz, E., Variation of Friction and Wear of Solid Lubricant Films with Film Thickness, ASLE Trans., 10, 1, (1967). Whitehouse, G.D., Nandan, D. and Whitehurst, C.A., The Effect of Film Thickness on Friction Coefficients for Solid Lubricants CaF2, MoSj and Graphite, ASLE Trans., 13, 159, (1970). 

Fig. 3. The effect of film thickness on band focusing, 500>Ul headspace injection test mixture, (Table 1) A — with liquid nitrogen B — without liqpid nitrogen...

The nanometer-scale thin film may be regarded as a two-dimensional grown film on the GC substrate, so the thickness of the film is an important parameter characterizing the dimension of the film. The effects of film thickness on the AIREs were investigated quantitatively on nm-Pd/GC electrodes. Figure 9 shows a series of MSFTIR spectra recorded on nm-Pd/GC electrodes of different film thickness [dm) measured by using an STM [38,39]. We can observe that following the increase of <7m the intensity of the CO2 band is increased continuously, while the intensity of the... 

The effect of film thickness on Tg can also be determined by measuring the surface softening temperature of corresponding polymer films using a heated AFM-like tip in scanning thermal probe microscopy. Scanning thermal probe microscopy probes the change in film modulus via the cantilever deflection induced by the thermal probe. As shown in Fig. 4.31, the cantilever deflects markedly when the PS film softens and hence, the onset of the Tg can be assessed. Systematic studies showed that PS on SiC>2 exhibits an altered Tg for film thicknesses below 50 nm. 

Wang and Feng have reported on the effect of film thickness on the mechanical properties of PTh films prepared using the same Lewis acid/hydrogen scavenger... 

Note that the C term varies directly with carrier gas velocity and the B term varies inversely. Dispersion due to the mass transfer term, C, is a function of the component/stationary phase interaction and is the critical dispersion term. There are two components, mass transfer in the mobile phase. Cm, and in the stationary phase, Cs- Figure 5.3 shows the van Deemter/Golay plots for packed and WCOT columns and the effect of film thickness. 

As discussed in Chapter 11, experimental results suggest that material properties of UTR films can differ in significant ways from their bulk counterparts. Of particular interest, because of its influence on the viscoelastic behavior of the spin-coated films, is the effect of film thickness on Eg (see Eig. 17.29), which decreases with film thickness for the particular substrate investigated in the study. 

The effect of film thickness on penetration of UV radiation Into the films should also be considered. If optimization of film thickness were to be based only on the predictions presented In... 

HM Princen. Highly concentrated emulsions I. Real systems. The effect of film thickness and contact angle on the volume fraction of creamed emulsions. J Colloid Interlace Sci 71 246, 1980. 

Equation 24.1.iv by Jasuja [8] is very similar to 24.1.iii. However, one key factor is that it is missing the effect of film thickness. The layout of the equation is the same it contains two terms, and the exponents on most of the variables are identical. The difference is in the GLR ratio, where the exponent is equal only to 0.5, as opposed to 2 in 24.1.iii. The equation predicts very coarse atomization. The difference can... 

Orzechowski derived two more correlations, one for kerosene 24.7.x, and the other for a water-glycerin mixture 24.7.xi. The correlations are said to be a functirm of film thickness, Weber number and Ohnesorge s number. The effect of film thickness and Weber number remains unchanged on both liquids. The difference arises in Ohnesorge s number, where the exponent is slightly lower for kerosene. Figure 24.46 shows a comparison of the two equations, using t = 0.1 nun. 

Microphase-separated block copolymer films have been investigated by numerous authors (257,258). van den Berg and co-workers reported on the film structures of poly(styrene-6Zoc butadiene-6Zoc -styrene) (SBS) triblock copolymers of PB and PS (259). In particular, the effect of film thickness on the observed morphology was unraveled for this system. 

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