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2092. Steen, M.L., L. Hymas, E.D. Havey, N.E. Capps, D.G. Castner, and E.R. Fisher, “Low temperature plasma treatment of asymmetric polysulfone membranes for permanent hydrophilic surface modification,” J. Membrane Science, 188, 97-114, (Jun 2001).

A plasma treatment that renders asymmetric polysulfone membranes permanently hydrophilic is reported. Our modification strategy entails treating these membranes downstream from an inductively coupled rf plasma source. Contact angle measurements confirm that the membranes are completely wettable with water as a result of H2O plasma treatment. More importantly, the hydrophilic modification is permanent as plasma-treated membranes remain wettable for more than 16 months after plasma treatment. This treatment achieves the desired change in wettability for microporous as well as ultrafiltration polysulfone membranes, illustrating the universality of this method. XPS analysis of treated membranes demonstrates this dramatic change in wettability is a result of chemical changes in the membrane induced by plasma treatment. Moreover, the membrane modification is complete as the plasma penetrates the thickness of the membrane, thereby modifying the entire membrane cross-section.

2023. Luner, P.E., and E. Oh, “Characterization of the surface free energy of cellulose ether films,” Colloids and Surfaces A: Physicochemical and Engineering Aspects, 181, 31-48, (Jun 2001).

The objective of this study was to determine the surface free energy components of aqueous-based cellulose ether films and compare these values with those of other cellulose polymers. The surface free energy parameters were calculated from the contact angles of sessile drops of apolar and polar liquids on cellulose ether films cast on glass slides using the Lifshitz–van der Waals/acid–base (LW/AB) approach according to the method of van Oss, Chaudhury and Good. The cellulose ethers studied were hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), hydroxypropyl cellulose (HPC) and hydroxyethyl cellulose (HEC). The total surface free energy of these cellulose ethers ranged from 42 to 50 mJ m−2. The contribution of the acid–base (AB) component of surface free energy to the total surface free energy of the polymers ranged from 4 to 12%, which was considerably lower than that of cellulose. The cellulose ethers demonstrated near monopolarity and had dominant electron donor (Lewis-base) character. The overall trend in the values of the thermodynamic terms derived from the surface free energy parameters as indicators of hydrophilicity and hydration were in good agreement with the relative bulk solubility and hydration behavior of the polymers. Independent estimates of the AB character of the polymers from work of adhesion terms calculated from the liquid wetting data agreed with those obtained from the surface free energy parameters. Calculation of the work of adhesion with substrates of varying surface free energy parameters indicated that acid–base interactions made a major contribution to the total work of adhesion between cellulose ethers and bipolar surfaces. Although no direct correlation could be established between the surface free energy parameters and the type of substitution on the cellulose backbone for the cellulose ethers, the values of the terms derived from the LW/AB approach were consistent with those of cellulose and ethylcellulose. The LW/AB approach provides a reasonably consistent method for estimating the surface properties of cellulose ethers and the resulting surface free energy parameters are shown to relate to the interfacial properties of the polymers.

1816. Napartovich, A.P., “Overview of atmospheric pressure discharges producing nonthermal plasma,” Plasmas and Polymers, 6, 1-14, (Jun 2001).

Recently, much attention has been paid to gas discharges producing nonthermal plasma because of many potential benefits in industrial applications. Historically, past work focused on Dielectric Barrier (silent) Discharges (DBD) and pulse-periodical corona discharges. Recently, a number of new different discharge techniques succeeded in producing stable gas discharge at atmospheric pressure. Among these are repetitively pulsed glow discharge; continuous glow discharge in a gas flow; hollow-cathode atmospheric pressure discharge; RF and microwave (MW) discharges. Several new variants of the DBD have been demonstrated over a rather wide range of frequencies. All these forms of gas discharge are characterized by a strong nonequilibrium plasma state. We attempt to classify these discharges with respect to their properties, and an overview of possible applications is made. Conditions for the existence of homogenous and filamentary forms of each of the discharge types are discussed.

881. Meichsner, J., “Low-temperature plasmas for polymer surface modification,” in Low Temperature Plasma Physics: Fundamental Aspects and Applications, Hippler, R., S. Pfau, M. Schmidt, and K.H. Schoenbach, eds., 453-472, Wiley-VCH, Jun 2001.

388. Wolf, R.A., “Corona treating & the printing process,” Flexo, 26, 58-59, (Jun 2001).

2856. no author cited, “Dynamic surface tension and surface energy in ink formulations and substrates,” https://www.pcimag.com/articles/85879-dynamic-surface-tension-and-surface-energy-in-ink-formulations-and-substrates, May 2001.

2081. Lawrence, J., and L. Li, “Modification of the wettability characteristics of polymethyl methacrylate (PMMA) by means of CO2, Nd:YAG, excimer and high power diode laser radiation,” Materials Science and Engineering A, 303, 142-149, (May 2001).

The surface of the bio-material polymethyl methacrylate (PMMA) was treated with CO2, Nd:YAG, excimer and high power diode laser (HPDL) radiation. The laser radiation was found to effect varying degrees of change to the wettability characteristics of the material depending upon the laser used. It was observed that interaction with CO2, Nd:YAG and HPDL effected very little change to wettability characteristics of the PMMA. In contrast, interaction of the PMMA with excimer laser radiation resulted an increase in a marked improvement in the wettability characteristics. After excimer laser treatment the surface O2 content was found to have increased and the material was seen to be more polar in nature. The work has shown that the wettability characteristics of the PMMA could be controlled and/or modified with laser surface treatment. However, a wavelength dependence of the change of the wetting properties could not be deduced from the findings of this work.

1934. Charbonnier, M., M. Romand, H. Esrom, and R Seebock, “Functionalization of polymer surfaces using excimer VUV systems and silent discharges: Application to electroless metallization,” J. Adhesion, 75, 381-404, (May 2001).

New approaches for electroless plating of nonconductive polymers or polymer-based materials are described. In this work, polyimide substrates were surface-functionalized (i) in nitrogenated (ammonia at reduced pressure) and oxygenated (air at atmospheric pressure) atmospheres under assistance of vacuum-ultraviolet (VUV) irradiation (use of a xenon silent discharge excimer source) or (ii) directly in air at atmospheric pressure using a dielectric-barrier discharge (DBD) device. After functionalization, the substrates were “activated” by dipping in a dilute acidic PdCl2 solution or by spin-coating of a thin metal-organic film (from a solution of palladium acetate (PdAc) in chloroform). The catalytic activity of the so-deposited palladium species toward the electroless deposition of nickel was studied before and after a VUV post-irradiation (in air at atmospheric or reduced pressure) with a view to understanding better the role of the reducer (sodium hypophosphite) within the electroless bath.

This work confirms the specific interest of grafting nitrogenated functionalities onto polymer surfaces for attaching covalently the palladium-based catalyst (in particular in the case of the PdCl2 route), forming thus strong Pd - N - C bonds at the metal/polymer interface. This results from the strong chemical affinity of palladium toward nitrogen. On the other hand, when oxygenated functionalities are surface-grafted, the conventional two-step procedure using SnCl2 and PdCl2 solutions can be proposed due to the strong chemical affinity of tin toward oxygen. The Ni deposits obtained under these different conditions pass the standard Scotch®-tape test and, therefore, exhibit a good practical adhesion. For this same purpose, it is interesting to note that the DBD treatment operating in air at atmospheric pressure causes an increase of the surface roughness and, therefore, an improvement in adhesion of metallic films when their initiation is catalyzed through the PdAc route. In addition, this work demonstrates that extensive research still has to be performed to understand and improve the Ni/polymer adhesion when the PdAc route associated with a VUV irradiation is considered.

1114. Greig, S., and N. Jadon, “Corona, ozone and flame treaters for extrusion coating lines,” in 8th European Polymers, Films, Laminations and Extrusion Coatings Conference, TAPPI Press, May 2001.

1112. DiGiacomo, J.D., “Fundamentals of flame plasma surface treating,” in 8th European Polymers, Films, Laminations and Extrusion Coatings Conference, TAPPI Press, May 2001.

960. Jingxin, L., H. Guangjian, L. Qiman, and L. Xiaohong, “Surface structure and adhesive properties of biaxially oriented polypropylene film grafted with poly(acrylic amide) using corona discharge,” Polymer Engineering and Science, 41, 782-785, (May 2001).

Corona discharge was explored as a means of forming chemically active sites on the surface of biaxially oriented polypropylene (BOPP) film. The active species formed in air was used to induce graft copolymerization of acrylic amide (AAM) in aqueous solution. The surface structure, hydrophilicity and adhesion of the grafted BOPP film were characterized by the extent of grafting, electron spectroscopy for chemical analysis (ESCA), scanning electron microscopy (SEM), peel strength and contact angle measurements. Surface graft-copolymerization of AAM onto BOPP film by corona discharge in air can be carried out with high efficiency. With increasing copolymerization time, the degree of grafting of AAM onto BOPP increases. The degree of grafting achieved a relatively high value of 2.13 wt% for the conditions of 1 min corona discharge and a copolymerization reaction time of 2.5 hr in 20% AAM aqueous solution at 70°C. After corona discharge grafting, the contact angle of water on the BOPP film decreased and the peel strength increased compared with those for ungrafted BOPP film. The hydrophilicity and adhesion of BOPP were improved by surface graft copolymerization with AAM induced by corona discharge.

882. Petrie, S.P., and E.F. Bardsley, “Epoxy adhesives: Effect of plasma treatment and surface roughness on epoxy to polyethylene bond strength,” in ANTEC 2001 Conference Proceedings, 1175-1178, Society of Plastics Engineers, May 2001.

2839. Yildirim, I., “Surface Free Energy Characterization of Powders, Chapter 2: Determination of surface free energies of talc from contact angles measured on flat and powdered surfaces (PhD thesis),” Virginia Tech, Apr 2001.

1245. Park, S.-J., and J.-S. Jin, “Effect of corona discharge treatment on the dyeability of low-density polyethylene film,” J. Colloid and Interface Science, 236, 155-160, (Apr 2001).

The effect of corona discharge on low-density polyethylene (LDPE) film was studied in terms of surface functionality and surface energetics of the film surfaces, improving the dyeability. The introduction of a polar group (ODouble BondCSingle BondO, CDouble BondO, and CSingle BondO) to a corona-treated LDPE film with acrylic acid could be confirmed by ESCA. The Owens–Wendt and Wu models using geometric means were studied to analyze the surface free energy of corona-treated film. It was found that the corona-treated LDPE film did lead to an increase in surface free energy, mainly due to the increase of its specific (or polar) component as the corona discharge power increased. Also, the K/S values were increased as the concentrations of dye increased. From the acid–base interaction point of view, it was found that the graft polymerization of acrylic acid onto the corona-treated LDPE film plays an important role in growing the acidic character which is one of the specific components of surface free energy, resulting in improving the dyeability with basic dyeing agent. A direct linear relationship is shown between the O1s/C1s ratio and the resulting K/S value or the specific component for this work.

1170. Brynolf, R., “Method and apparatus for treating substrate plastic parts to accept paint without using adhesion promoters,” U.S. Patent 6582773, Apr 2001.

895. Holman, S., “What's your problem?,” Australian Flexo, (Apr 2001).

547. Podhajny, R.M., “Water-based ink adhesion and web temperature,” Paper Film & Foil Converter, 75, 26, (Apr 2001).

2481. Shieh, S., “An analysis of contact angle measurement,” AST Products, Mar 2001.

249. Mount, E.M. III, “Plasma pretreatment for metalizing packaging film,” Converting, 19, 124-131, (Mar 2001).

2407. Miranda, R., “Double corona treatment,” U.S. Patent 6190741, Feb 2001.

1439. Kaplan, S.L., and D.J. Naab, “PSAs tenaciously bond to non-stick film after plasma treatment,” Adhesives and Sealants Industry, 8, 40-42, (Feb 2001).

1280. Ogawa, T., H. Mukai, and S. Osawa, “Improvement of the mechanical properties of an ultrahigh molecular weight polyethylene fiber/epoxy composite by corona-discharge treatment,” J. Applied Polymer Science, 79, 1162-1168, (Feb 2001).

The interfacial shear strength of an ultrahigh molecular weight (UHMW) polyethylene (PE) fiber/epoxy-resin system was greatly improved by the corona-discharge treatment of the fiber. The UHMW PE-fiber/epoxy-resin composite was prepared with corona-discharge-treated UHMW PE fiber. The mechanical properties of the composite sheet were determined by tensile testing. The tensile strength of the composite was also very much improved. However, the tensile strength of the composite was about one-half of the theoretical strength. This result was due to the molecular degradation of the PE-fiber surface caused by surface modification. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1162–1168, 2001
https://onlinelibrary.wiley.com/doi/abs/10.1002/1097-4628%2820010214%2979%3A7%3C1162%3A%3AAID-APP20%3E3.0.CO%3B2-Y

1276. Jana, T., B.C. Roy, R. Ghosh, and S. Maiti, “Biodegradable film, IV. Printability study on biodegradable film,” J. Applied Polymer Science, 79, 1273-1277, (Feb 2001).

A starch-based biodegradable (BD) low density polyethylene (LDPE) film can be directly printable without any corona treatment, unlike virgin LDPE film. Such a film shows poor adhesion and nail scratch resistance of the ink on the printed area of the film. In order to increase the adhesion and nail scratch resistance of the ink on the printed BD film, grafting of acrylonitrile onto the BD film is carried out. The polyacrylonitrile grafted BD film shows better adhesion, nail scratch resistance, and printability. The printability of the polyacrylonitrile grafted BD film is comparable to the conventional corona treated LDPE film. The extent of printability is a function of the surface smoothness, as well as the optimum percentage of grafting on the biodegradable film. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1273–1277, 2001
https://onlinelibrary.wiley.com/doi/abs/10.1002/1097-4628(20010214)79:7%3C1273::AID-APP150%3E3.0.CO;2-L

623. De Coninck, J., “Is there an optimal substrate geometry for wetting (at the microscopic scale)?,” in Interfacial Properties on the Submicrometer Scale (ACS Symposium Series 781), Frommer, J., and R.M. Overney, eds., 24-35, American Chemical Society, Feb 2001.

The Young's equation is the well-known relationship used to describe a sessile drop at equilibrium on top of a solid surface. This relationship has been discussed thermodynamically and microscopically for purely flat surfaces in the literature. To characterize the non-flatness of a surface, one may introduce the Wenzel's roughness r defined as the area of the wall surface devided by the area of its projection onto the horizontal plane. Obviously, r is equal to 1 once the surface is flat. For r>1, it is known that Young's equation has to be modified to take into account the increase of surface. The generalization of Young's relation is the so-called Wenzel's law. In this presentation, we will study this relation within microscopic models. We will in particular show that the roughness may enhance the wetting of the substrate even at the microscopic scale.

2518. Inagaki, N., S. Tasaka, and S. Shimada, “Comparative studies on surface modification of poly(ethylene terephthalate) by remote and direct argon plasmas,” J. Applied Polymer Science, 79, 808-815, (Jan 2001).

Surface modification of poly(ethylene terephthalate) (PET) film by an argon (Ar) plasma was investigated as a function of the distance from the Ar plasma zone. Changes in distance between the PET film and the Ar plasma zone had a strong influence on the surface modification of the film. The direct Ar plasma treatment (distance between the PET film and Ar plasma zone = 0 cm) was effective in hydrophilic surface modification, but heavy etching reactions occurred during the modification. On the other hand, the remote Ar plasma treatment (distance between the PET film and Ar plasma zone = 80 cm) modified the PET film surfaces to be hydrophilic without heavy etching reactions, although the hydrophilicity of the PET was lower than that by the direct Ar plasma. The remote Ar plasma treatment was distinguished from the direct Ar plasma treatment from the viewpoint of degradation reactions. The remote Ar plasma treatment rather than the direct Ar plasma treatment was an adequate procedure for surface modification and caused less polymer degradation on the film surface. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 808–815, 2001
https://onlinelibrary.wiley.com/doi/10.1002/1097-4628(20010131)79:5%3C808::AID-APP50%3E3.0.CO;2-B

2054. Woods, S.S., and A.V. Pocius, “The influence of polymer processing additives (PPAS) on the surface and optical properties of polyolefin plastomer blown film,” J. Plastic Film and Sheeting, 17, 62-87, (Jan 2001).

Polyolefin plastomer films formulated with slip and antiblock were blown on a wide die gap with and without two Dynamar polymer processing additives (PPAs). A wide die gap was used so that melt fracture-free film could be obtained with no PPA present for comparison purposes. The films were analyzed for the following properties: surface tension (on treated films), gloss, haze, clarity, transmittance, hot tack, heat seal, COF and block. In addition, the surface of films was examined using ESCA (Electron Spectroscopy for Chemical Analysis) and SSIMS (Static Secondary Ion Mass Spectrometry) to determine the surface chemical composition. PPAs when used at typical dose levels were shown to have essentially no effect on the surface and optical properties of plastomer films.

1554. Sesetyan, T., “Testing equipment,” Label & Narrow Web, 6, 36-43, (Jan 2001).

962. Novak, I., and S. Florian, “Influence of ageing on adhesive properties of polypropylene modified by discharge plasma,” Polymer Intl., 50, 49-52, (Jan 2001).

The adhesive properties of isotactic polypropylene with different degrees of crystallinity, surface-modified by corona discharge plasma have been studied, during the process of ageing. Considerable decrease in the surface free energy and its polar component was observed. A significant correlation was found between the mechanical work of adhesion to polyvinyl acetate and the polar fraction during ageing. The influence of the crystallinity of the polymer on the resulting adhesion parameters of aged polypropylene foil was confirmed. © 2001 Society of Chemical Industry

878. Schramm, L.L., Dictionary of Colloid and Interface Science, Wiley-Interscience, Jan 2001.

239. Millward, J., “A trick to treat?,” Package Printing, 48, 40-45, (Jan 2001).

2765. Roth, J.R., D.M. Sherman, F. Karakaya, P.P.Y. Tsai, K. Kelly-Wintenberg, and T.C. Montie, “Increasing the surface energy and sterilization of nonwoven fabrics by exposure to a one atmosphere uniform glow discharge plasma (OAUGDP),” International Nonwovens J., 10, 34-47, (2001).

A technique for generating active species with the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has been developed and used to sterilize and increase the surface energy, wettability and wickability of nonwoven fabrics. The OAUGDP is a non-thermal, fourth-state-of-matter plasma with the classical characteristics of a low pressure DC normal glow discharge that operates in air (and other gases) at atmospheric pressure. No vacuum system or batch processing is necessary, and a wide range of applications to fabrics and polymeric webs can be accommodated in a parallel plate plasma reactor. In addition to directly exposing webs and workpieces to active species for surface energy increase in a parallel-plate reactor, we have shown that active species capable of sterilization can be convected at near room temperature to a remote exposure chamber. This technology is simple, produces many effects that can be obtained in no other way, generates minimal pollutants or unwanted byproducts, and is suitable for online treatment of webs, films, and fabrics.

Early exposures of nonwoven fabrics to the OAUGDP required minutes to produce relatively small increases of surface energy. These durations appeared too long for commercial application to fast-moving webs. Recent improvements in OAUGDP power density, plasma quality and impedance matching of the power supply to the parallel plate plasma reactor have made it possible to raise the surface energy of a variety of polymeric webs (PP, PET, PE, etc.) to levels in the range of 60 to 70 dynes/cm with one second of exposure. In most cases these high surface energies were not durable, and fell off to 50 dynes/cm after periods of weeks to months. Here, we report the exposure of nonwoven fabrics made of PP and PET at the UTK Textiles and Nonwovens Development Center (TANDEC) to an impedance matched parallel plate OAUGDP for durations ranging from one second to several tens of seconds. Data will be reported on the surface energy, wettability and wickability as functions of time of exposure, and of the aging effect after exposure. We will report the use of a OAUGDP with air as the working gas to sterilize a broad range of microorganisms on a variety of surfaces, and in several distinct applications. These include a Remote Exposure Reactor to sterilize large workpieces 20 centimeters or more from the plasma-generating region, and a sterilizable air filter.

2572. Mikula, M., and M. Cernak, “More effective corona for prepress treatment of polymeric foils,” in Proceedings of the 4th Seminar on Graphic Arts Technology, 82-88, Pardubice, Czech Republic, 2001.

2101. Schroder, K., A. Meyer-Plath, D. Keller, W. Besch, G. Babucke, and A. Ohi, “Plasma-induced surface functionalization of polymeric biomaterials in ammonia plasma,” Contributions to Plasma Physics, 41, 562-572, (2001).

Plasma-chemical modification is frequently used to improve the adaption of polymer surfaces to biological environments. In this regard amino functional groups play a key role. They provide an excellent basis for subsequent modifications with specific biomolecules. It would be of great value to get an amino functionalization independent of the specific material in use. The paper reports on an investigation concerning the feasibility of such an universal plasma functionalization procedure. Two different downstream microwave plasma sources were taken to apply a procedure, which was developed for high-grade modification of polystyrene (PS), to a number of other polymers including polyetheretherketone (PEEK), polyethyleneterephthalate (PET), polyethylenenaphthalate (PEN), polycarbonate (PC), polyethylene (PE), polymethylmethacrylate (PMMA) and fluorinated polymers. In many cases, very similar results were obtained. At maximum 5% of the surface were covered by nitrogen functional groups. In some cases, about 50% of total nitrogen functional groups were amino groups. The results suggest that a downstream ammonia plasma treatment indeed is a fairly universal method for high performance amino functionalization of polymeric biomaterials.

1728. Novak, I., and S. Florian, “Effect of short-time aging on hydrophilicity of discharge plasma pretreated biaxially oriented polypropylene,” Petroleum and Coal, 43, 29-30, (2001).

The adhesion of polypropylene and printing with various dyestuffs represents a serious problem which cannot be solved in satisfactory manner without modification. Because of practical usability, simple manipulation, suitability to continuous modification processes and efficiency the modification by plasma produced by electric discharge at atmospheric pressure in the medium of air oxygen was used. The free surface energy value of discharge-plasma pretreated biaxially oriented polypropylene in the course of short-time aging was determined. The free surface energy of modified polypropylene two weeks after modification exceeds the empirically established value 38 mJ.m-2, that is regarded as a condition of acceptable surface modification of discharge plasma modified polypropylene foils.

1727. Novak, I., and I. Chodak, “Effect of polypropylene UV modification on adhesion to polar polymers,” Petroleum and Coal, 43, 27-28, (2001).

Surface modification of iPP in vapors of phosphoryl chloride under UV irradiation is an effective method for the increase of adhesive properties. Phosphoryl chloride acts as an sensitizer that decomposes under the effect of UV irradiation.

1694. Clint, J.H., “Adhesion and components of solid surface energies,” J. Current Opinions on Colloid and Interface Science, 6, 28-33, (2001).

Contact angle data for sets of probe liquids allow the determination of components of solid surface energies which in turn can be used to calculate the work of adhesion of other materials to the solid surface. There is much debate currently about the correct choice of the acid–base components for the probe liquids. For many systems, the strength of adhesion measured independently correlates well with the calculated work of adhesion. Recent trends in this area include adhesion under water and the adhesion of bacterial and other cells to immersed solids.

1687. Massines, F., G. Gouda, N. Gherardi, M. Duran, and E. Croquesel, “The role of dielectric barrier discharge atmosphere and physics on polypropylene surface treatment,” Plasmas and Polymers, 6, 35-49, (2001).

Dielectric barrier discharge (DBD) is the discharge involved in corona treatment, widely used in industry to increase the wettability or the adhesion of polymer films or fibers. Usually DBD's are filamentary discharges but recently a homogeneous glow DBD has been obtained. The aim of this paper is to compare polypropylene surface transformations realized with filamentary and glow DBD in different atmospheres (He, N2, N2 + O2 mixtures) and to determine the relative influence of both the discharge regime and the gas nature, on the polypropylene surface transformations. From wettability and XPS results it is shown that the discharge regime can have a significant effect on the surface transformations, because it changes both the ratio of electrons to gas metastables, and the space distribution of the plasma active species. This last parameter is important at atmospheric pressure because the mean free paths are short (∼μm). These two points explain why in He, polypropylene wettability increase is greater by a glow DBD than by a filamentary DBD. In N2, no significant effect of the discharge regime is observed because electrons and metastables lead to the same active species throughout the gas bulk. The specificity of a DBD in N2 atmosphere compared to an atmosphere containing oxygen is that it allows very extensive surface transformations and a greater increase of the polypropylene surface wettability. Indeed, even in low concentration and independently of the discharge regime, when O2 is present in the plasma gas, it controls the surface chemistry and degradation occurs.

1588. Kersten, H., H. Deutsch, H. Steffan, G.M.W. Kroesen, and R. Hippler, “The energy balance at substrate surfaces during plasma processing,” Vacuum, 63, 385-431, (2001).

A summary is given of different elementary processes influencing the thermal balance and energetic conditions of substrate surfaces during plasma processing. The discussed mechanisms include heat radiation, kinetic and potential energy of charged particles and neutrals as well as enthalpy of involved chemical surface reactions. The energy and momentum of particles originating from the plasma or electrodes, respectively, influence via energy flux density (energetic aspect) and substrate temperature (thermal aspect) the surface properties of the treated substrates. The various contributions to the energy balance are given in a modular mathematical framework form and examples for an estimation of heat fluxes and numerical values of relevant coefficients for energy transfer, etc. are given. For a few examples as titanium film deposition by hollow cathode arc evaporation, silicon etching in CF4 glow discharge, plasma cleaning of contaminated metal surfaces, and magnetron sputtering of aluminum the energetic balance of substrates during plasma processing will be presented. Furthermore, the influence of the resulting substrate temperature on characteristic quantities as etching or deposition rates, layer density, microstructure, etc. will be illustrated for some examples, too.

1437. Kunz. M., and M. Bauer, “Adhesion to plastic,” Farbe und Lack, 107, 54-62, (2001).

Polyolefins and fluoropolymers have a major drawback: they don't adhere to polymer surfaces properly. If these substrates do have to be coated, however, there are three different approaches to improving adhesion. One is to change the coating, another is to modify the polymer surface, and the third is to apply some kind of adhesion promoter. One successful process which could solve this problem comprises a combination of a plasma pre-treatment and an additional thin acrylated photoinitiator coating. The result is that the purely physical bond gives rise to a covalent chemical bond between the polymer surface and the coating. Further advantages offered by this process are discussed in this article.

1356. Abdel-Salam, M., H. Singer, and A. Ahmed, “Effect of the dielectric barrier on discharges in non-uniform electric fields,” J. Physics D: Applied Physics, 34, 1219-1234, (2001).

This paper is aimed at calculating the electric field in the point-to-plane electrode system with the plate covered with a dielectric layer. With charge accumulation on the dielectric surface by corona discharge, the field in the dielectric is increased at the expense of a decrease in the gas gap. The charge accumulation on the dielectric surface proceeds to the maximum possible value when the normal component of the surface field vanishes. With the dielectric layer fully-charged, the percentage decrease of the field in the gas gap is maximum at the dielectric surface and declines along the gap axis to vanish at the point tip. The percentage decrease of the field becomes more pronounced with the increase of the diameter of the dielectric layer. The effect of inter-electrode spacing and the dielectric layer thickness on the field distribution is investigated. An accurate method of charge simulation was used for field calculation irrespective of the thickness of the dielectric layer and the gap geometry. With ion flow along the flux lines from the stressed point to the ground plane, the field enhancement factor increases and the volume charge density decreases along the flux lines. The voltages of the ion flow threshold and corona quenching are calculated and compared with previous measurements. The method of calculation is extended to calculate how high the surface potential of the charged dielectric needs to be to trigger a micro-spark in the electrostatic discharges from grounded point electrodes.

 

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