PTFE Surface Research Articles

Functionalization of PTFE and Si(100) surfaces by consecutive graft polymerization of glycidyl and aniline monomers

Chemical modification of argon plasma-pretreated poly(tetrafluoroethylene) (PTFE) film and Si(100) surfaces by UV-induced surface graft polymerization with glycidyl methacrylate (GMA) and glycidyl acrylate (GA), respectively, followed by epoxide-ring opening reaction with aniline (An), and finally oxidative graft polymerization with aniline had been carried out to render the PTFE and silicon surfaces electroactive. The composition and microstructure of the graft-polymerized PTFE and silicon surfaces were studied by X-ray photoelectron spectroscopy (XPS). The physicochemical characteristics of the polyaniline (PANI) chains grafted onto PTFE film and silicon surfaces were grossly similar to those of the PANI homopolymer. The surface resistance of the aniline graft-polymerized PTFE film and silicon substrate was reduced to between 10 4 Ω/□and 10 7 Ω/□.

Surface passivation of epoxy resin with a covalently adhered poly(tetrafluoroethylene) layer

Surface passivation of epoxy resin with a covalently adhered poly(tetrafluoroethylene) (PTFE) layer was achieved by casting the epoxy resin on a surface-modified PTFE film, followed by thermal curing and mechanical delamination. Surface modification of the PTFE film was carried out by argon plasma pre-treatment, followed by UV-induced graft copolymerization with acrylic acid (AAc), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (HEMA) and acrylamide (AAm). The compositions and microstructures of the corresponding AAc-g-PTFE, GMA-g-PTFE, HEMA-g-PTFE and AAm-g-PTFE surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and water contact angle measurements, respectively. In all cases, the graft yield increased with the argon plasma pre-treatment time of the PTFE film and the monomer concentration. Thermal curing of the epoxy resin on the graft-copolymerized PTFE surfaces (the AAc-g-PTFE and GMA-g-PTFE surfaces, in particular) resulted in strong adhesion of the epoxy resin on the PTFE surface. The strong adhesion arose from the curing of the grafted AAc or GMA chains into the epoxy resin matrix to form a highly cross-linked interphase, as well as the fact that the AAc or the GMA chains were covalently tethered on the PTFE surfaces. The strong adhesion also resulted in cohesive failure inside the PTFE substrate during mechanical delamination to give rise to a passivated epoxy resin surface with a covalently adhered PTFE layer.

Electroless Plating of Copper and Nickel on Surface-Modified Poly(tetrafluoroethylene) Films

Chemical modification of Ar plasma-pretreated poly(tetrafluoroethylene) (PTFE) film by UV-induced graft copolymerization with glycidyl methacrylate (GMA), followed by reactive coupling of 3-aminopropyltriethoxysilane (APS), or reactive immobilization of polyaniline (PANI) chains had been carried out to improve the adhesion of the electrolessly deposited copper and nickel to PTFE film. The surface compositions and microstructures of the modified PTFE films were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The PANI-modified PTFE surface was susceptible to the electroless deposition of copper and nickel in the absence of sensitization by The adhesion strength of the PANI-modified or silane-modified PTFE film with the electrolessly deposited metal was affected by the graft concentration of the GMA polymer, the Ar plasma post-treatment, the graft-modified PTFE surface, and the extent of thermal post-treatment after metallization. The optimum T-peel adhesion strength of the electrolessly deposited metal on the graft-copolymerized and APS-coupled PTFE film could reach about 13 N/cm. This adhesion strength represented a more than tenfold increase over that obtained when the PTFE film was modified by Ar plasma treatment alone. The mechanisms of the adhesion strength enhancement, thermal stability enhancement, and cohesive failure of the metal-PTFE interface were also investigated. © 2001 The Electrochemical Society. All rights reserved.

Lamination of conductive polypyrrole films to poly(tetrafluoroethylene) films via interfacial graft copolymerization

A simple technique for the lamination of a conductive polymer film to an inert dielectric polymer film was demonstrated. The electrochemically synthesized and p-toluenesulfonic acid-doped polypyrrole (PPY) film was laminated simultaneously to the argon plasma-pretreated PTFE film during the thermally induced graft copolymerization of the PTFE surface with a functional monomer. The graft copolymerization was carried out using glycidyl methacrylate (GMA) monomer containing 20% v/v hexamethyldiamine (HMDA) and in the absence of any polymerization initiator. Thermally induced graft copolymerization of the GMA monomer on the PPY surface was minimal. The lap shear and T-peel adhesion strengths of the laminates were found to be dependent on the GMA graft concentration on the PTFE surface, which, in turn, was affected by the plasma pretreatment time of the film. To increase the GMA graft concentration for the enhancement of adhesion strength, the plasma-pretreated PTFE surfaces were premodified via UV-induced graft copolymerization with GMA prior to the simultaneous thermal graft copolymerization and lamination process. The modified surfaces and interfaces were characterized by X-ray photoelectron spectroscopy (XPS). Through XPS measurements of the delaminated surfaces, it was found that the PPY/PTFE laminates failed predominantly by cohesive failure inside the PTFE substrate. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 716–727, 2001

Laser Ablation of Transparent Materials by UV fs-Laser Irradiation.

We have investigated the laser ablation of UV transparent materials of PTFE, FEP, quartz and sapphire with a femtosecond-pulsed UV laser at the wavelength of 268nm. Upon laser irradiation, a fine etching without debris was obtained on the surfaces of PTFE and quartz. The laser-ablated surfaces were analyzed by optical microscopy. The ablation mechanism is discussed in terms of multi-photon absorption and thermal diffusion induced by a ultra-short pulse of the laser.

Surface Graft Copolymerization of Poly(tetrafluoroethylene) Films with N-Containing Vinyl Monomers for the Electroless Plating of Copper

Argon plasma-pretreated poly(tetrafluoroethylene) (PTFE) films were subjected to UV-induced surface graft copolymerization, under atmospheric conditions, with several N-containing vinyl monomers, including 4-vinylpyridine (4VP), 2-vinylpyridine (2VP), 1-vinylimidazole (VIDz), 1-vinylpyridinone (VPD), and acrylamide (AAm). Electroless plating of copper could be carried out effectively on the 4VP or 2VP graft-copolymerized PTFE surface after PdCl2 activation and in the absence of SnCl2 sensitization. The surface compositions of the modified PTFE films were studied by X-ray photoelectron spectroscopy (XPS). The catalytic processes for the electroless plating of copper in the presence and absence of sensitization by SnCl2 were compared. The adhesion strength of the electrolessly deposited copper on the graft-modified PTFE surface was affected by the type of the monomers used for graft copolymerization, the graft concentration, and the activation time of the PTFE surface in PdCl2 solution. The T-peel adhesion strength between the electrolessly deposited copper and the graft-modified PTFE film was further improved in the absence of the SnCl2 sensitization step and could reach as high as 7 N/cm. However, the electroless deposition of copper could not be carried out on the pristine or Ar plasma-treated PTFE surface in the absence of SnCl2 sensitization.

Consecutive Graft Copolymerization of Glycidyl Methacrylate and Aniline on Poly(Tetrafluoroethylene) Films

Chemical modification of Ar plasma-pretreated poly(tetrafluoroethylene) (PTFE) film by UV-induced graft copolymerization with glycidyl methacrylate (GMA), followed by oxidative graft copolymerization of aniline and reactive immobilization of polyaniline (PANI) chains have been carried out to render the PTFE surface conductive. The surface compositions and microstructures of the graft-copolymerized PTFE films were studied by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The PANI chains grafted onto PTFE film surface were similar to the PANI homopolymer. The surface resistance of the aniline graft-copolymerized PTFE film could be reduced to the order of about 104 Ω/sq, compared to the order of 1016 Ω/sq for the pristine PTFE film. Cohesive failure occurred inside the bulk of PTFE film when an epoxy adhesive was applied to peel off the grafted PANI layer from the GMA graft-copolymerized PTFE substrate. The strong adhesion arose from the fact that the PANI chains were...

Surface modification of aluminum foil and PTFE film by graft polymerization for adhesion enhancement

Modification of aluminum foils via surface graft polymerization of glycidyl methacrylate (GMA) to promote their adhesion to the similarly modified poly(tetrafluoroethylene) (PTFE) films is reported. The properly cleaned surface of the aluminum foil was first silanized with 3-(trimethoxysilyl)-propyl-methacrylate (APS). The silanized Al foil was pretreated with Ar plasma to generate peroxides and hydroperoxides before been subjected to UV-induced graft polymerization of GMA (the Al-APS-g-GMA surface). The Ar plasma-pretreated PTFE film was similarly modified by UV-induced graft copolymerization with GMA (the GMA-g-PTFE surface). The modified aluminum and PTFE surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. The adhesion between the Al foil and the PTFE film was achieved by introducing a small amount of GMA and hexamethylenediamine (HMDA) solution mixture or HMDA alone at the lapped interface, followed by curing at elevated temperature. T-peel adhesion strength of ∼13 N cm −1 was achieved for the Al-APS-g-GMA/GMA+HMDA/GMA-g-PTFE assembly, compared to only ∼5 N cm −1 attainable in the corresponding Al/GMA+HMDA/GMA-g-PTFE assembly involving only the pristine Al foil. Similarly, the use of GMA graft-copolymerizied PTFE film resulted in a significant increase in adhesion strength of the Al/PTFE assembly over that obtained using only the plasma-treated PTFE film. Cohesive failure in the bulk of the PTFE substrate was observed for the Al-APS-g-GMA/GMA+HMDA/GMA-g-PTFE assembly.

Surface Functionalization of Poly(tetrafluoroethylene) Films via Consecutive Graft Copolymerization with Glycidyl Methacrylate and Aniline

Chemical modification of argon-plasma-pretreated poly(tetrafluoroethylene) (PTFE) film by UV-induced surface graft copolymerization with glycidyl methacrylate (GMA), followed by epoxide-ring-opening reaction with aniline (An), and finally oxidative graft polymerization with aniline had been carried out to render the PTFE surface conductive. The surface composition and microstructure of the graft-copolymerized PTFE films were studied by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The graft concentration of the GMA polymer and An polymer increased with increasing concentration of the respective monomer used for graft polymerization. Ethanol, when used as a solvent, catalyzed the coupling reaction of epoxide with An and should be of more than 40 vol % in concentration to achieve the optimum effect. The physicochemical characteristics of the polyaniline (PANI) chains grafted onto PTFE film surface were grossly similar to those of the PANI homopolymer. The surface resistance of the aniline graft-polymerized PTFE film was reduced to the order of about 104 Ω/square, in comparison to the value of 1016 Ω/square for the pristine PTFE film.

Multicomponent sequential injection analysis determination of nitro-phenols in waters by on-line liquid-liquid extraction and preconcentration

An automatic sequential injection analysis (SIA) set-up for the determination of phenolic compounds (2-, 3- and 4-nitrophenol) in waters was designed and evaluated. The system performs an on-line phenol extraction from an aqueous medium to an organic solvent, which enables the analyte isolation and preconcentration. The extracted phenols are on-line back-extracted into a small volume of NaOH solution and conducted to a spectrophotometric detector for quantitative analysis. This methodology is based on the formation of a thin organic solvent layer adhered to the PTFE surface of the extraction coil. In the present work, no reversed-flow was carried out in both the extraction and back-extraction steps. By using a photodiode-array detector, multilinear regression algorithms and first derivative spectroscopic techniques were evaluated in order to perform multicomponent determinations of phenol mixtures. Concentrations within the range 0.4–4.6 mg l −1 of 2-nitrophenol, 0.6–11.2 mg l −1 of 3-nitrophenol and 55.6–938 mg l −1 of 4-nitrophenol have been determined and simultaneously analysed at a frequency of four samples per hour. A R.S.D. of 2.2% was obtained for 2.6 mg l −1 of 2-nitrophenol, 2.3% for 5.3 mg l −1 of 3-nitrophenol and 2.2% for 330.8 μg l −1 of 4-nitrophenol, with preconcentration factors comprised between seven and nine.

Surface modification of poly(tetrafluoroethylene) films by low energy Ar + ion-beam activation and UV-induced graft copolymerization

Surface modification of poly(tetrafluoroethylene) (PTFE) films by Ar + ion-beam irradiation with varying ion energy and ion dose was carried out. The changes in surface composition of the irradiated PTFE films were characterized, both in situ and after exposure to air, by X-ray photoelectron spectroscopy (XPS). The possible mechanisms of chemical reaction induced by the incident ion beam on the surface of PTFE film included defluorination, chain scission and cross-linking, as indicated by the presence of the characteristic peak components associated with the CF 3,CF, and C(CF 2) 4 species in the C 1s core-level spectra, the decrease in surface [F]/[C] ratio, and the increase in surface micro-hardness of the Ar + ion-beam-treated PTFE films. Furthermore, the free radicals generated by the ion-beam could react with oxygen in the air to give rise to oxidized carbon species, such as the peroxides, on the PTFE surface. Thus, after exposure to air, the Ar + ion-beam-pretreated PTFE films were susceptible to further surface modification by UV-induced graft copolymerization with a vinyl monomer, such as acrylamide (AAm). The graft concentrations were deduced from the XPS-derived surface stoichiometries. The Ar + ion energy and the ion dose affected not only the surface composition of the treated films but also the graft copolymerization efficiency of the corresponding pretreated films.

Thermal imidization of poly(amic acid) precursors on surface-modified poly(tetrafluoroethylene) films via graft copolymerization with glycidyl methacrylate

A novel method for preparing composites of polyimides (PI) laminated to poly(tetrafluoroethylene) (PTFE) films is reported. PI/PTFE composites were developed through thermal imidization of poly(amic acid) (PAA) precursors on surface-modified PTFE films. Surface modification of PTFE films was carried out via Ar plasma pretreatment of the films, followed by UV-induced graft copolymerization with glycidyl methacrylate (GMA). The surface composition and topography of the graft copolymerized PTFE films and the delaminated PI and PTFE surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The adhesion strengths of the PI (imidized PAA) on the GMA graft copolymerized PTFE films were evaluated as a function of various thermal imidization schedules. The adhesion reliability of the PI/PTFE composites was tested by a series of hydrothermal cycles. The development of strong Tpeel adhesion strengths of about 8 N/cm with excellent reliability for the PI/PTFE composites was attributable to the synergistic effect of coupling the curing of the epoxide functional groups of the grafted GMA chains with the imidization process of the PAA and the fact that the GMA chains were covalently tethered onto the PTFE surface. The PI/PTFE composites delaminated via cohesive failure inside the PTFE substrates. The delaminated PI film with a covalently adhered 'rough' PTFE surface layer exhibited a water contact angle as high as 140°.

Modification of poly(tetrafluoroethylene) and gold surfaces by thermal graft copolymerization for adhesion improvement

The adhesion between a poly(tetrafluoroethylene) (PTFE) film and a gold substrate was achieved by surface graft copolymerization of glycidyl methacrylate (GMA) on an argon plasma-pretreated PTFE film at elevated temperature with simultaneous lamination to a surface-modified gold substrate. The plasma pretreatment introduces peroxides which are thermally degraded into radicals to initiate the graft copolymerization of GMA on the PTFE surface. The gold surface, on the other hand, was first pretreated with 3-mercaptopropionic acid (MPA), 3-mercaptopropionic acid-2-ethylhexyl ester (MPAEE), or (3-mercaptopropyl)trimethoxysilane (MPTMS) to form self-assembled monolayers (SAMs) and then subjected to Ar plasma treatment. The simultaneous graft copolymerization and lamination of the PTFE film to the gold surface was carried out in the presence of GMA and an amine hardener at an elevated temperature under atmospheric conditions. The modified surfaces and interfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The gold/GMA/PTFE assembly exhibited a T-peel adhesion strength above 10 N/cm and the joint delaminated by cohesive failure inside the bulk of the PTFE film. The strong adhesion of the Au/PTFE laminate is the result of concurrent graft copolymerization on both the Ar plasma-pretreated PTFE surface and the SAM of the Au surface to form a covalent network. The network is further strengthened by the crosslinking reaction promoted by the presence of the hardener.

Surface modification of poly(tetrafluoroethylene) films via grafting of poly(ethylene glycol) for reduction in protein adsorption

Poly(tetrafluoroethylene) (PTFE) films with surface grafted poly(ethylene glycol) (PEG) chains were prepared by two methods: (1) UV-induced graft copolymerization of methoxy poly(ethylene glycol) monomethacrylate (PEGMA) onto the plasma-pretreated PTFE films; and (2) coupling of the hydroxyl groups of PEG via ester linkages with the carbonyl chloride groups which were introduced onto the acrylic acid (AAc) graft-copolymerized PTFE surface through reaction with thionyl chloride (SOCl2). The UV-induced graft copolymerization of PEGMA onto the plasma-pretreated PTFE film was explored with different macromonomer concentrations and different UV graft copolymerization time. The coupling reaction, on the other hand, was explored with PEG of different molecular weights. The surface microstructures and compositions of the PEGmodified PTFE films from both processes were characterized by contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) measurements. In general, higher macromonomer concentration and longer UV graft copolymerization time led to a higher graft yield for the UV-induced graft copolymerization with PEGMA. Contact angle measurements revealed that the hydrophilicity of the PTFE film surface was greatly enhanced by the grafting of the PEG chains. The PTFE surface with a high density of grafted PEG was very effective in preventing bovine serum albumin adsorption.

Investigation of wet chemical-treated poly(tetrafluoroethylene) surface and its metallization with SIMS, XPS and atomic force microscopy

Surface modification and metallization of poly(tetrafluoroethylene) (PTFE) surface via a wet chemical treatment was studied. The wet process included a pretreatment using Na/naphthalene/THF solution as an etchant followed by an electroless copper plating. The existence of Na in the substrate top layer down to several micrometers was detected by Secondary Ion Mass Spectrometry (SIMS) and was thought to be the key element which made it possible to deposit electroless copper onto the PTFE surface. The topographies of the pretreated surfaces were examined by SEM and the nanometer-size surface roughnesses were characterized by Atomic Force Microscopy (AFM). Chemical changes on the surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. A comparison of copper adhesion was performed by the scribe-grid test and a good agreement with F/C ratio was obtained. The effects of treatment time and Na/naphthalene ratio on wettability, surface roughness, fluorine removal, copper adhesion as well as the locus of failure are discussed.

Ammonia RF-Plasma on PTFE Surfaces: Quantification of the Species Created on the Surface by Vapor - Phase Chemical Derivatization

AbstractA cylindrically-configured plasma treatment system in Radio Frequency Glow Discharges fed with ammonia was used with the aim of modifying the internal surface of ePTFE arterial prostheses to improve their biocompatibility. In order to understand the effects of this treatment on the PTFE polymer surface, we have first realized RF-plasma treatment experiments on PTFE films. Preliminary XPS analyses have shown that about 15% of the surface atoms were substituted by nitrogen (N/C ratio of 0.3) whereas the F/C ratio decreased from 2 to 0.6, therefore leading to the conclusion that several chemical species are created onto the surface upon an ammonia plasma treatment. As X-Ray Photoelectron Spectroscopy (XPS) analysis does not allow the direct determination of the nature of the N-species grafted on the surface (chemical shifts are not different enough), vapor phase chemical derivatization was carried out on PTFE films to quantify the concentration of these new surface moities grafted on the polymer surface.

Adhesion and adhesion reliability enhancement of evaporated copper on surface modified poly(tetrafluoroethylene) films from graft copolymerization

Surface modifications of Ar plasma-pretreated poly(tetrafluoroethylene) (PTFE) film via UV-induced graft copolymerization were carried out to improve the adhesion and adhesion reliability with evaporated copper. The PTFE film surface was modified by graft copolymerization with a monomer, such as 2-hydroxylethyl methacrylate (HEMA), acrylic acid (AAc), methacrylic anhydride (MAAn), and glycidyl methacrylate (GMA). A double graft copolymerization process, involving initially the graft copolymerization with HEMA, AAc or MAAn, which contained the functional moities for curing the epoxide groups, and subsequently by graft copolymerization with GMA, which contained the epoxide group, was also employed. The adhesion strength of the evaporated Cu on the singly and doubly graft-copolymerized PTFE film was affected by the type of monomer used during graft copolymerization, the concentration of the graft, the extent of O/sub 2/ plasma post-treatment after graft copolymerization, and the extent of thermal treatment after metallization. The T-type peel adhesion strength of the Cu/PTFE laminate obtained under the optimum conditions was about 19 N/cm. The adhesion strengths of the Cu/PTFE laminates remained practically unchanged after the Level I test (85/spl deg/C and 85% relative humidity for 168 h). The good adhesion strength and adhesion reliability must have resulted from the strong affinity of the graft chains for Cu, the extensive crosslinking of the graft chains at the metal/polymer interface, and the fact that the graft chains where covalently tethered on the PTFE surface. The cohesive failure of the metal/polymer laminates was also investigated.

Factors affecting the UV emission from pulsed surface discharges

The emission properties of pulsed electrical discharges propagating across the surfaces of PET, PP, PTFE, UPVC, and PVDF in various gases have been investigated. The optical spectra from the discharges have been recorded over the 200-500 nm bandwidth and the effect of the interaction between the pulsed discharge and the substrate material studied. The gases used were air, argon, and SF/sub 6/ at pressures in the range 0.1-1 bar. In comparison to the other gases, SF/sub 6/ was found to produce the most intense continuum and line emission within the 200-300 nm spectral region. The substrate material was found to affect both the intensity of continuum spectra and the content of the discrete line spectra. When PTFE was employed, the continuum spectra was more intense compared to that of the other materials. In contrast, the use of PVC resulted in a considerable modification to the composition of the discrete line spectra.

Reactive adsorption of aminosilane onto the glycidyl methacrylate graft‐copolymerized poly(tetrafluoroethylene) film surface for adhesion enhancement with evaporated copper

Surface modification of argon-plasma-pretreated poly(tetrafluoroethylene) (PTFE) film via UV-induced graft copolymerization with glycidyl methacrylate (GMA) was carried out first. Reactive adsorption of γ-aminopropyltriethoxysilane (APS) onto the GMA graft-copolymerized PTFE (GMA-g-PTFE) film surface was performed by the simple immersion of the film in the APS solution. The adsorption process was studied as a function of the APS concentration, the immersion time of the graft-modified PTFE film in the APS solution, and the washing protocol. The chemical composition and morphology of the silane-modified surfaces were characterized by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. The performance of the silane-modified PTFE surface in adhesion promotion was investigated. The T-peel adhesion strength of the evaporated Cu on the PTFE film with the reactively adsorbed organosilane increased significantly to about 12.5 N/cm. This adhesion strength was more than twice that of the assembly involving evaporated Cu on the GMA-g-PTFE film and about 10 times that of the assembly involving evaporated Cu on the Ar-plasma-treated PTFE film. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 80–89, 2000

Reactive adsorption of aminosilane onto the glycidyl methacrylate graft-copolymerized poly(tetrafluoroethylene) film surface for adhesion enhancement with evaporated copper

Surface modification of argon-plasma-pretreated poly(tetrafluoroethylene) (PTFE) film via UV-induced graft copolymerization with glycidyl methacrylate (GMA) was carried out first. Reactive adsorption of γ-aminopropyltriethoxysilane (APS) onto the GMA graft-copolymerized PTFE (GMA-g-PTFE) film surface was performed by the simple immersion of the film in the APS solution. The adsorption process was studied as a function of the APS concentration, the immersion time of the graft-modified PTFE film in the APS solution, and the washing protocol. The chemical composition and morphology of the silane-modified surfaces were characterized by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. The performance of the silane-modified PTFE surface in adhesion promotion was investigated. The T-peel adhesion strength of the evaporated Cu on the PTFE film with the reactively adsorbed organosilane increased significantly to about 12.5 N/cm. This adhesion strength was more than twice that of the assembly involving evaporated Cu on the GMA-g-PTFE film and about 10 times that of the assembly involving evaporated Cu on the Ar-plasma-treated PTFE film. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 80–89, 2000