bluuebunny/crossref_metadata_2025_split huggingface dataset:
XPS analysis of thin oxide films on chemically treated aluminum alloy surfaces using a high‐energy Mg/Zr anode
Authors: Allgeyer Daniel F. , Pratz Earl H. 
Published: December 2004

AbstractA method for determining the aluminum oxide and aluminum metal atomic concentrations on complex aluminum alloy surfaces using a high‐energy Mg/Zr x‐ray source (1253.6 and 2042.4 eV, respectively) was discussed. XPS analysis of chemically processed aluminum surfaces using an Mg or Mg/Al anode limits the analysis of aluminum to the Al 2s and Al 2p photoelectron lines. Analysis of aluminum surfaces using the Al KLL Auger transition and the Mg or Mg/Al x‐ray source is accomplished with the bremsstrahlung radiation. The utility of the high‐energy Mg/Zr x‐ray anode is realized by offering the ability to qualitatively and quantitatively analyze aluminum using the Al KLL Auger region at 1374–1405 eV kinetic energy. The Al KLL Zr excited Auger transition provides a clear separation between the aluminum oxide and metal transitions (6.0 eV).
Identification of subnanometre surface layers on polymer films by surface‐enhanced infrared transmission spectroscopy
Authors: Nishikawa Yuji , Ito Yoshiaki , Yamakami Noriko , Fujiwara Kunihiro , Shima Tetsuo 
Published: December 2004

AbstractIdentification of subnanometre surface layers on polymer films, which are only analysable by x‐ray photoelectron spectroscopy (XPS) or secondary ion mass spectrometry (SIMS), have been demonstrated by the use of transmission surface‐enhanced infrared absorption (SEIRA) spectroscopy with the use of silver island films: 1.0 nm thick polydimethylsiloxane (PDMS) or 0.5 nm thick polymethylphenylsiloxane (PMPHS) surface layers, which are semisolid materials, on polyethyleneterephthalate (PET) films were successfully identifiable with the use of transmission SEIRA by measuring the PDMS or PMPHS that was transferred onto the silver‐deposited BaF2 substrates under pressure. This approach completely eliminates strong spectral interference from PET films by measuring the transferred surface layer and greatly improves the signal‐to‐noise ratio of the surface layer absorption with the use of silver island films. The detection limit of PDMS surface layers on PET films is ∼0.2 nm. The present method gives a considerable amount of information about surfaces, such as chemical composition and chemical structure. This is a highly promising method for analysiing subnanometre surface layers which consist of liquid or semisolid materials, such as oil, lubricant, plasticizer and surface‐active agent on polymer materials.
Quantitative Auger analysis of metal oxides
Authors: Zagorenko A. I. , Zaporozchenko V. I. , Ivanova O. P. 
Published: December 2004

AbstractCompositional changes of the surfaces of oxides ZnO, Al2O3, Y2O3, SiO2, GeO2, NiO and Nb2O5 induced by 3 keV Ar+ were quantitatively characterized by AES and XPS. The accuracy of Auger analysis based on the first‐principle calculation was estimated for the stable oxides. The results obtained enabled the most accurate algorithm for quantitative analysis of oxides to be selected. The measuring error was reduced to <3%. It was shown also that sputter‐induced compositional changes of oxide surfaces can be analysed satisfactory by AES.
The structure of pumice: An XPS and 27Al MAS NMR study
Authors: Venezia A. M. , Floriano M. A. , Deganello G. , Rossi A. 
Published: December 2004

AbstractIn order to investigate the surface structure of pumice, an amorphous aluminosilicate, samples of pumice and of standards of silica and alumina have been studied by x‐ray photoelectron spectroscopy (XPS). The effect of a mild acid leaching was also considered. The analysis of the Si 2p, Al 2p and O 1s photoelectron peaks and the Si KLL and O KLL Auger peaks indicated that pumice is formed by tetrahedral silica with some units being replaced by aluminate, AlO2−. The acid treatment decreases the alkali and the aluminate ions. X‐ray photoelectron spectra of the valence band of pumices and of standards of Al2O3 and SiO2 agree with the core‐level results. To support the conclusions from the XPS study, magic angle spinning (MAS) 27Al nuclear magnetic resonance (NMR) of pumice was used. The spectrum is indicative of tetrahedrally coordinated aluminium.
The influence of the oxide/metal interface composition on the adherence of oxide layers on metal substrates
Authors: Schmutzler H. J. , Viefhaus H. , Grabke H. J. 
Published: December 2004

AbstractWell adherent and corrosion‐protecting oxide layers are of great importance for high‐temperature alloys. The adherence of the oxide layers is affected by the morphology and the chemical composition of the oxide/metal interface. In this study scanning Auger microscopy (SAM) is used to investigate the oxide/alloy interface of oxidized FeCrAl alloys (undoped or doped with Ti, Ce and Y) after partly removing the oxide layer by in situ bending. The metal surface shows individual voids and rugged parts, indicating imprints of the removed oxide. For the undoped alloy poor adherence of the oxide layer is observed. Sulphur is strongly enriched at the surface of the voids. In several areas of the rough interface no sulphur was detected. On the Ti‐containing alloys the oxide layer is again poorly adherent. Sulphur is strongly enriched at the surface of the voids and at a lower but constant level at the rough area. On Y‐ and Ce‐containing alloys the oxide layer is well adherent and no sulphur enrichment is detectable beneath the scale. The poor adherence of the oxide layers on undoped and Ti‐doped FeCrAl alloys is correlated to the presence of sulphur at the alloy surface. Sulphur enrichment is explained by sulphur segregation to the free alloy surface for the undoped alloy and additional sulphide formation for Ti‐containing alloys. The positive effect of Y and Ce on the adherence of the oxide layer is explained by sulphide precipitation, preventing sulphur segregation to the free alloy surface.
Interfacial analyses of copper corrosion by acrylic and methacrylic acids using XPS, auger and grazing angle FTIR spectroscopy
Authors: Yang D. Billy , Wolf David 
Published: December 2004

AbstractWe have observed that methacrylic acid (MA) is far more corrosive than acrylic acid (AA) on copper surfaces when copper was exposed to the vapor of these two acids at ambient temperature and environment. With the aid of modern surface‐sensitive instrumentation, which included grazing angle Fourier transform infrared (FTIR), XPS, x‐ray‐induced Auger electron and SEM/energy‐dispersive spectroscopies and white light stereo and metallurgical microscopy, we are reporting our results of an extensive study of the roles that MA and AA have in this unusual phenomenon of copper corrosion.By grazing angle FTIR analysis we demonstrated that copper carboxylate salt formation is very rapid upon short contact with the vapor of both acids, and the acids showed no evidence of polymerization. We have also demonstrated by XPS and x‐ray‐induced Auger electron spectroscopy that copper surfaces exposed to the MA vapor contains mainly Cu(II) species. However, the oxidation state of the copper exposed to AA vapor will depend on exposure time and environment. With limited exposure to the air, the copper surface remained shiny for up to 12 months test time. The spectrum obtained from the shiny area of the AA/Cu surface shows that it contains mainly Cu(I) mixed with some copper (II). When the spectrum was taken from a dull area of AA/Cu surfaces, the Cu(II) state was found to be predominant. These results strongly indicate that when the shiny AA/Cu surface changed to a dull color, the oxidation state of the copper also changed from +1 to +2. The molecular structure of the Cu(II)–AA salt is also believed to be altered.Both stereo microscopic and SEM/energy‐dispersive spectroscopy techniques were also used to perform the visual and microanalysis of the surface texture and elemental compositions of the corroded surfaces, respectively. The presence of oxygen was also found to play an important role in the overall corrosion processes. The differences in molecular structure of copper carboxylate salts of different oxidation states are discussed and are believed to be responsible for this unusual phenomenon. We believe that this finding will provide a good explanation for the cause of drastic differences of copper corrosion by acrylic and methacrylic acids.
Determination of the surface coverage of Mo/Al2O3 catalysts
Authors: Sazo Virginia , Gonzales Lilian , Goldwasser José , Houalla Marwan , Hercules David M. 
Published: December 2004

AbstractThe surface coverage of a series of Mo/Al2O3 catalysts prepared by the equilibrium adsorption method was measured by CO2 chemisorption, low‐temperature CO adsorption and ion scattering spectroscopy (ISS). Comparable values were obtained from ISS and CO adsorption. The results correspond to Mo cross‐sections of 22.2 Å2 Mo−1 (CO) and 20 Å2 Mo−1 (ISS).The Mo coverages obtained by CO adsorption and ISS were compared with those estimated from CO2 chemisorption. The resuls indicated that, irrespective of the approach used to measure the coverage from CO2 chemisorption (volumetric method or from the decrease of the IR peaks attributed to bicarbonate and ‘free’ carbonate species), the CO2‐based method signficantly overestimates the coverage.
Quantitative determination of the passive layer on Cu–Ni alloys
Authors: Druska Peter , Strehblow Hans‐Henning 
Published: December 2004

AbstractCopper–nickel alloys are important materials for application in corrosive environments. As for many other systems, this property is a consequence of thin oxide films that are protective in weakly acidic and alkaline solutions. The passive layer formed potentiostatically in 1 M NaOH on Cu50Ni has been examined with XPS and ISS. Angular‐dependent XPS measurements provide an insight into the layered structure of depth profiles that are confirmed qualitatively and quantitatively by ISS sputter depth profiles. A method is presented to evaluate the XPS results on the basis of a multilayer structure. Thicknesses and the composition of the sublayers of the passive film, as well as the composition of the metal surface underneath, are obtained in dependence on electrochemical parameters such as potential and time of passivation. Thus, on obtains not only the chemical structure but also the changes of the passive layer during its formation. A specimen transfer in a closed system from the electrolyte into the ultrahigh vacuum of the spectrometer prevents possible changes of the passive layer. These measurements are a further example of detailed studies of passivating films on technically important alloys.
Test of elastic electron scattering corrections for quantitative XPS
Authors: Tougaard S. , Jablonski A. 
Published: December 2004

AbstractRatios of the experimental XPS peak intensities from seven metals were compared to two first‐principle theories corresponding to neglecting and including the effects of elastic electron scattering, i.e. the common formalism and the Monte Carlo model, respectively. The theoretical peak intensities were found to change by an average of 14% as a result of elastic scattering, but the standard deviation from experiment was practically the same, namely ∼15% for both theories. The deviation between experiment and theory is found to be random when elastic scattering is neglected, while a small systematic component is revealed when elastic scattering effects are included. The fact that no general reduction is observed in the deviation between experiment and theory is attributed to the error origination from parameters like the photoionization cross‐sections and the inelastic electron mean free paths. These errors apparently overshadow to a large extent the improvements of including the effects of elastic electron scattering.
EPA's viewpoint on lead and cadmium additives for PVC
Authors: Yager Kenneth A. 
Published: December 2004

AbstractIn addition to presenting the nature of the lead and cadmium hazard and environmental control levels, there is presented a philosophy, international in scope, for the meaningful management of EPA's legislated responsibilities to the citizens of the U.S. The profitable aspects of pollution control and waste recycling are discussed as exciting alternatives to the nonproductive character of compliance with regulations.
Lead stabilizer dispersion in PVC
Authors: Marx M. Fred 
Published: December 2004

AbstractAs a major consumer of lead stabilizers used in PVC wire and cable compounds, Western Electric raw material inspection personnel have seen a decline of lead stabilizer dispersion quality. For this reason, the dispersion of lead stabilizer is of major concern to us. Marginally dispersed stabilizers cause an excessive collection of lead compound on the extruder screen pack and eventual rupture of the screen. Marginal dispersion detracts from extrusion smoothness of high‐speed, thin‐wall wire insulation. Stabilizer manufacturers have acknowledged that dustless versions of their products are more difficult to disperse. Lead suppliers must meet OSHA regulations that limit employees' exposure to inorganic lead compounds. They are using different approaches that are producing a proliferation of packages as well as stabilizer surface treatments. Dispersion quality has varied from supplier to supplier and from lot to lot. Obviously, compounders find it difficult to agree on a solution to the problem. The use of bulk returnable air pallets and standard non‐treated stabilizer would satisfy dust‐level requirements, eliminate the need for additive treatment, and solve potential bag disposal restrictions.
Vinyl chloride‐ethylene copolymers: The effect of modest ethylene concentrations on the physical properties of compounds
Authors: Hanna Russell J. , Fields John W. 
Published: December 2004

AbstractVinyl chloride‐ethylene copolymers containing from 1.0 to 5.5 wt.% ethylene were synthesized and compounded with DOP plasticizer at levels of 0, 5, 10, 20, 30, and 40 parts per hundred parts of resin. Physical property tests indicated that, as an internal plasticizer, ethylene was 2 to 3 times more efficient than DOP in the range studied. An examination of room temperature modulus as well as brittleness also indicated that crystallinity was still apparent in all copolymers.
Reduction of notch sensitivity and improvement in low‐temperature impact strength of PVC
Authors: Mathur K. K. , Driscoll S. B. 
Published: December 2004

AbstractPVC is a notch‐sensitive polymer. The drop weight impact strength is also lost dramatically below 0°C. This requires special formulation considerations for critical applications. The general trend is to use polymeric impact modifiers, which are rubbery, graft polymers or blends of both hard and rubbery materials. This is achieved with some sacrifice in flexural modulus and formulation economics. A recent study conducted to relate calcium carbonate particle size with notched Izod and low‐temperature drop weight impact strength has shown that the stearate‐coated Ultrafine precipitated calcium carbonate (0.07 μ), at 15 phr loading, substantially improves both properties without sacrifice in flexural modulus. The formulation cost is also favorable. It is hypothesized that improvement in the above properties is primarily due to uniform stress distribution and lack of defect structure, as observed with coarse fillers. Surprisingly, the optimum‐particle‐size, coated, precipitated calacium carbonates also improved the Ultraviolet light stability of the PVC.
Velocity profile of rigid PVC in an extrusion die
Authors: Brown Randy J. 
Published: December 2004

AbstractA method to determine the velocity profile of a melt within the die for both opaque and transparent materials shows that, above the crystalline melt temperature, the velocity profile of PVC follows the power‐law relationship. Below the crystalline melt temperature, the velocity of PVC is flatter and more like plug flow than is predicted by the power‐law relationship because the high elastic modulus (due to crystallinity) leads to slippage at the wall or melt fracture. Knowledge of the expected velocity profile can be used to design dies to compensate for higher velocity in the center.
Raw material variables in flexible vinyl dry blending and extrusion
Authors: Payne Marc T. , Cannon Joseph A. 
Published: December 2004

AbstractMedium‐molecular‐weight resins with medium to high porosity have the best processing characteristics of resins normally used for flexible vinyl. Plasticizers improve dryblending and fusion time by their molecular weight and solvating efficiency. Formulations should account for the effect of ingredients on processing and on expected end‐use properties. Flexible vinyl extrusions would then be produced more efficiently and have better physical properties—at lower total cost.
Development of a flame‐resistant noncontaminating PVC jacket for coaxial cable
Authors: Loadholt J. T. , Kaufman Stanley 
Published: December 2004

AbstractThe migration of plasticizer from a PVC jacket into the polyethylene core of a coaxial cable can significantly alter the high‐frequency transmission characteristics of the cable by effectively increasing the dissipation factor of the polyethylene. In order to determine the effect of plasticizer type on transmission loss, a series of PVC‐jacketed polyethylene core coaxial cables was manufactured, each jacket with a different plasticizer. Transmission loss was found to be directly related to plasticizer volatility. A linear trimellitate plasticizer gave stable electrical performance with a good balance of properties, including processing, cost, and fire resistance.
Plastisol copolymers of polyvinyl chloride opportunities for energy efficiencies
Authors: Hurter David R. 
Published: December 2004

AbstractSimple substitution of PVC copolymer dispersion resins can offer some processing advantages over their homopolymer counterparts, in either reduced temperatures or shorter cycles. Elevated storage temperatures can affect the viscosity of the copolymer compound, but minimal reformulating (substituting a less‐solvating plasticizer in part or whole or pre‐wetting the compound with a few parts of a diluent, such as mineral spirits) can usually restore stability. The formulator must be the final judge of the compensatory steps to be taken.
Injection‐molding rigid PVC compounds
Authors: Murrey Jerry L. 
Published: December 2004

AbstractRigid PVC compounds will be specified for an ever‐increasing number of diverse applications within the next few years because of their excellent cost‐performance balance. Molders with experience and equipment to run these compounds will share in this growing business. Those grounded in the basic principles of molding rigid PVC compounds will gain the confidence and develop the capability for processing many other thermoplastics, besides reaping the profits.
Formulations for vinyl house siding: History, present, future
Authors: Summers James W. 
Published: December 2004

AbstractIn the early 1960s, vinyl house siding was first commercialized. The colors were pastels and included white, green, yellow, and gray. All siding tended to bleach and fade (oxidize) to an extent where medium and dark colors were unacceptable, since the fading is more noticeable in deeper colors. All the early siding was made from cubes on single‐screw extruders. Powder compounds were first introduced in the late 1960s, as was twin‐screw extrusion. At the same time higher processing temperatures were used on, both twin‐ and single‐screw extruders. That led to a well‐fused and tougher product. Formulation changes reduced bleaching and fading and permitted such medium‐depth colors as tan, gold, beige, blue, and olive.This technology allowed rapid growth in the vinyl siding industry in the late 1970s. Surface distortion (oil canning) was recognized as a potential problem with the early gray color and recognized as a major problem with dark colors; it was resolved only by understanding the fundamental principles involved. Another major problem was the fading in dark colors and here again extensive research into the principles of weathering led to the use of a thin, highly weatherable capping as a cost‐effective solution.For the future, many technical developments can be expected in this rapidly growing market. However, judging by the occasional withdrawal of a formulation from the market, and by an occasional homeowner complaint, present performance in several properties must be judged as just adequate. For this market to continue its rapid growth, future performance should be better than today's. This can be accomplished without hurting economics by careful understanding of all parameters involved. Formulation changes will allow better performance. Standards must be raised to control product performance, especially surface distortion and color stability in darker colors, and to insure retention of physical properties after long‐term weathering.
Heat transfer study of vinyl extrusion cooling rates
Authors: Limansky Joseph , Bochner Michael 
Published: December 2004

AbstractThis paper deals with a method of determining the midplane temperatures of vinyl extrusions. Knowing the surface temperature, cooling medium temperature, and flow rates, the theoretical midplane temperature can be calculated. Determining and controlling midplane temperatures of vinyl extrudates is essential for consistent part fabrication. Data are presented illustrating how flow rate of the cooling medium affects surface and midplane temperatures of the vinyl extrudate. Enthalpy and flow rate data are used to determine cooling bath requirements.
Processing and formulation effects on gel levels in flexible PVC extrusions
Authors: Pazur A. S. 
Published: December 2004

AbstractGels, or fisheyes, in flexible PVC extruded or calendered products are the ∼ 150 μm PVC grains which, for one reason or another, survive the compounding and processing steps to appear as defects on the surface of the profile, sheet, or film. In most applications they are aesthetically objectionable. In other applications, such as medical tubing or blood bags, they are functionally intolerable. Gels are a function of resin and plasticizer selection, processing temperature, residence time at temperature, and shear history. In flexible PVC extrusion, process parameters include cube or pellet versus powder processing, barrel L/D, screw compression ratio, screw RPM, and temperature profile. Choice of resin is, of course critical. Resin morphological parameters of importance include friability, porosity, and absence of glassy particles. Plasticizers vary greatly in their ability to solvate the PVC grain. Various types of dry blend and resin contamination result in large increases in gels.
Dielectric studies of poly(vinyl chloride)
Authors: Utracki L. A. , Jukes J. A. 
Published: December 2004

AbstractMeasurements of the dielectric constant and loss factor of polyvinyl chloride (PVC) have been made over a wide range of temperature and frequency. Maxima in dielectric loss were observed at a temperature corresponding to the α or glass transition temperature and secondary β transition temperature. The sensitivity of these maxima to both frequency and thermal pretreatment was investigated. It was found that the position of the β peak on the temperature axis changed markedly with frequency, while the glass transition or α peak showed only small variations. Neither the α nor the β peak were very sensitive to thermal pretreatment, but interesting changes in the minimum between these peaks were observed. In quenched samples a distinct shoulder peak at Tβ < Ts < Tα was observed; it was possible to eliminate it by a slow cooling of the samples. The effect of plasticizer content was also studied.