Showing papers on "Surface modification published in 1993"
TL;DR: A review of the development and trends in surface modification by low-pressure plasma treatment can be found in this paper, where reference is also made to other surface modification techniques, particularly to corona treatment, and comparisons are made wherever appropriate.
Abstract: Since the earliest systematic research during the 1960s, the field of materials surface modification by 'cold', low-pressure plasma treatment has undergone an enormous expansion. Much of this expansion has taken place in recent years, particularly in the surface modification of polymeric materials, for which there now exist numerous industrial applications (enhancement of paint adhesion, improved bonding in polymer matrix composites, etc.). In this paper, we provide a critical review of the development and trends in this field; reference is also made to other surface modification techniques, particularly to corona treatment, and comparisons are made wherever appropriate. We begin with a brief overview of adhesion theory, and of the physics and chemistry of 'cold' plasmas. Next, interaction mechanisms between a plasma and a polymer surface are examined; these include physical bombardment by energetic particles and by ultraviolet photons, and chemical reactions at or near the surface. The resulting four mai...
957 citations
Book•
01 Jan 1993
TL;DR: In this paper, the relationship between surface analysis and surface modification techniques is discussed, and various methods for modifying the surfaces of polymers for certain applications are described, including adhesives, biomaterials, protective coatings, and composites.
Abstract: Illustrates the relationship between surface analysis and surface modification techniques. Polymers for use in adhesives, biomaterials, protective coatings, and composites need specific chemical and physical properties. These properties include: composition, hydrophilicity, roughness, crystallinity, conductivity, and lubricity. Various methods for modifying the surfaces of polymers for certain applications are described.
478 citations
TL;DR: Sulfur‐based molecules containing biotin and hydroxyl groups have been used to create a wide variety of self‐assembled monolayer on gold surfaces to study in situ the binding of streptavidin to these monolayers from solution.
Abstract: Sulfur‐based molecules containing biotin and hydroxyl groups have been used to create a wide variety of self‐assembled monolayers on gold surfaces. Surface plasmon resonance has been used to study in situ the binding of streptavidin to these monolayers from solution. The self‐assembled monolayers allow a high degree of control over the surface properties. The choice of an appropriate biotin‐containing molecule, with a spacer segment, and the dilution of this molecule within the monolayer by hydroxythiols, allows optimization of the binding properties of the monolayer—nonspecific interactions between streptavidin and the surface are below detection limits, and specific binding between the streptavidin and biotin groups can be maximized.
344 citations
TL;DR: Methods of surface modification with water-soluble polymers, such as polyethylene oxide, albumin, and heparin, are reviewed, which have significantly improved the blood compatibility of polymeric biomaterials.
Abstract: Appropriate surface modification has significantly improved the blood compatibility of polymeric biomaterials. This article reviews methods of surface modification with water-soluble polymers, such as polyethylene oxide (PEO), albumin, and heparin. PEO is a synthetic, neutral, watersoluble polymer, while albumin and heparin are a natural globular protein and an anionic polysaccharide, respectively. When grafted onto the surface, all three macromolecules share a common feature to reduce thrombogenicity of biomaterials. The reduced thrombogenicity is due to the unique hydrodynamic properties of the grafted macromolecules. In aqueous medium, surface-bound water-soluble polymers are expected to be highly flexible and extend into the bulk solution. Biomaterials grafted with either PEO, albumin, or heparin are able to resist plasma porotein adsorption and platelet adhesion predominantly by a steric repulsion mechanism.
338 citations
TL;DR: In this article, surface modification of poly(tetrafluoroethylene) (PTFE) films by radio frequency argon plasma treatment as well as by graft copolymerization of the plasma-pretreated films with acrylamide (AAm) has been carried out.
Abstract: Surface modification of poly(tetrafluoroethylene) (PTFE) films by radio frequency argon plasma treatment as well as by graft copolymerization of the plasma-pretreated films with acrylamide (AAm) has been carried out. XPS results show that mild plasma treatment is sufficient to cause substantial surface defluorination end oxidation. The oxygen functionalities incorporated greatly facilitate subsequent graft copolymerization in the presence of near-UV radiation. Strong plasma treatment, on the contrary, results in considerable cross-linking of polymers on the surface and thus has an adverse effect on the graft copolymerizetion
259 citations
237 citations
TL;DR: The surface modification of AISI 316 stainless steel by plasma immersion ion implantation (PI3) has been investigated over a range of treatment temperatures as discussed by the authors, and the results are similar to those obtained by conventional ion beam implantation of nitrogen, but the depth of nitrogen penetration increases dramatically with temperature.
Abstract: The surface modification of AISI 316 stainless steel by plasma immersion ion implantation (PI3) has been investigated over a range of treatment temperatures. Below 250°C the results are similar to those obtained by conventional ion beam implantation of nitrogen, but the depth of nitrogen penetration increases dramatically with temperature. Up to 450 °C a nitrogen-expanded austenite phase is formed which is shown to have improved corrosion performance over the untreated material. At 520 °C chromium nitride is precipated and the expanded austenite transforms to martensite, leading to a reduction in corrosion resistance. Pin-on-disc testing indicates improved wear resistance at all temperatures, with reduction in the wear volume by factors of several hundred at high loads. This can be attributed to the formation of an oxide layer which prevents the initiation of severe metallic wear.
230 citations
TL;DR: The results suggest that nanoparticles designed for use as injectable drugs or drug carriers should display similar surface characteristics provided by such amphiphilic surface modifiers.
188 citations
TL;DR: In this article, the chemical effects of both inert (argon) and reactive (oxygen, nitrogen, and mixed gas) plasma treatments done in situ on a variety of polymer surfaces were studied.
Abstract: X-ray photoelectron spectroscopy (XPS) has been used to study the chemical effects of both inert (argon) and reactive (oxygen, nitrogen, and mixed gas) plasma treatments done in situ on a variety of polymer surfaces. Inert gas plasma treatments introduce no new detectable chemical species onto the polymer surface but can induce degradation and rearrangement of the polymer surface. However, plasma treatments with reactive gases create new chemical species which drastically alter the chemical reactivity of the polymer surface. These studies have also shown that the surface population of chemical species formed after plasma treatment is dependent on both the chemical structure of the polymer and the plasma gas. The effects of direct and radiative energy-transfer processes in a plasma have also been studied. Polymers containing certain functional groups were found to be more susceptible to damage via radiative energy transfer. Ageing studies of plasma-modified polymer surfaces exposed to the atmosphere have s...
163 citations
Patent•
03 Nov 1993
TL;DR: In this paper, a multifunctional reagent is used for the attachment of desired molecules to appropriate support surfaces, in order to provide the surfaces with desired properties, and a reagent molecule of the invention is restrained in that it is conformationally and/or chemically restricted from reacting either with itself or with other molecules of the same reagent.
Abstract: A multifunctional reagent useful for the attachment of desired molecules to appropriate support surfaces, in order to provide the surfaces with desired properties. A reagent molecule of the invention is restrained in that it is conformationally and/or chemically restricted from reacting either with itself or with other molecules of the same reagent, thereby allowing for varied applications.
162 citations
TL;DR: In this paper, a new method of surface modification by electrical discharge machining using composite structured electrode surface modifications on work pieces of carbon steel or aluminum were carried out in hydrocarbon oil using composite electrodes Composite electrode consists of green compact products or sintered products Copper, aluminum, tungsten carbide and titanium were used for the material of the electrode, it was revealed that there existed the electrode material in the work surface layer and the characteristics of the surface of raw material remarkably changed
TL;DR: In this article, the surface properties of cellulose fibers have been modified by heat treatment, by silane coupling agents, and by maleated polypropylene grafts, which yielded information on the fibers' acid/base interaction potential.
Abstract: The surface properties of cellulose fibers have been modified by heat treatment, by silane coupling agents, and by maleated polypropylene grafts. The effectiveness of these methods has been evaluated by electron spectroscopy (ESCA), by contact angle measurements, and by inverse gas chromatography. The latter analyses yielded information on the fibers' acid/base interaction potential. Cellulose was found to be amphoteric, with prevalent acidic properties. Heat and chloro-silane treatments accentuated acidity, while amino-silane treatment produced net basicity in the fiber surface. Modification with maleated polypropylene reduced specific interactions and converted the fiber to a predominantly dispersion-force solid. The modified fibers were used in composites with polypropylene (neutral), polystyrene (base), and chlorinated polyethylene (acid) as matrix. Stress/strain and dynamic mechanical parameters were found to vary with acid/base interactions between polymer and fiber, significant improvements being noted in elastic and storage moduli, in tensile strength and elongation. In polypropylene, properties were unaffected by acid/base considerations. Acid/base forces, not necessarily dominant, merit consideration in the design of surface modification strategies intended to optimize composite mechanical properties.
02 Jun 1993-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: A review of surface modification with beams of gas cluster ions is given in this article, where damage, implantation, and surface erosion with 5-30 kV cluster ions of Ar and CO 2 are discussed in the context of earlier results obtained at higher energies.
Abstract: A review of recent data on surface modification with beams of gas cluster ions is given. Damage, implantation, and surface erosion with 5–30 kV cluster ions of Ar and CO 2 are discussed in the context of earlier results obtained at higher energies. It is concluded that gas cluster ion beams may find new interesting applications for very shallow implantation, amorphization and surface smoothing.
TL;DR: In this paper, a new method for surface modification to cover particle surface with fine particles mechanically in a dry phase by making use of comminution techniques is discussed, and it is demonstrated that this method has great feasibility to fabricate composite particles by the combination of various kinds of core/fine particles.
Abstract: This paper reviews a new method for surface modification to cover particle surface with fine particles mechanically in a dry phase by making use of comminution techniques.First, the relation of comminution process with surface modification technology is discussed, and the advanced machines developed in Japan to treat core particles surface with fine particles based on grinding principles are introduced. Then, the details of the composite process of core/fine particles with these machines are explained.In the second section, the effects of the controlling factors on the composite process such as mechanical actions, treating temperature and atmosphere are discussed.The third section deals with the conditions of combinations of core/fine particles acceptable to this method, and it is demonstrated that this method has a great feasibility to fabricate composite particles by the combination of various kinds of core/fine particles. The scale-up of these machnines is explained in the fourth section, and a typical example is introduced.The last section summarizes the applications of the composite particles fabricated by this method to create various kinds of new materials, which include the application for surface modification technology. The applications of this method are shown to expand for other types of processing such as rounding particles and mixing different kinds of powder materials precisely. Furthermore, it is also explained that this method can fabricate composite particles inside which different kinds of components are dispersed.
TL;DR: X-ray photoelectron spectroscopy was used to characterize modified surfaces of a biomedically important polymer, poly(ethylene terephthalate), finding direct silanization with 3-aminopropyltriethoxysilane to be the optimum procedure, resulting in an aminated surface.
Abstract: X-ray photoelectron spectroscopy was used to characterize modified surfaces of a biomedically important polymer, poly(ethylene terephthalate). Several modification schemes were investigated and direct silanization with 3-aminopropyltriethoxysilane was found to be the optimum procedure, resulting in an aminated surface. Surface coverage of up to 100% was achieved with retention of the polymeric structural integrity. Further activation of the silanized surface was accomplished with two cross-linkers, glutaraldehyde and sebacoyl chloride. A simple biomolecule, L-cysteine, was successfully immobilized onto a surface pre-treated with 3-aminopropyltriethoxysilane and glutaraldehyde, with a coverage of 42%.
TL;DR: In this paper, Fourier transform infrared spectroscopy was used in the transmission mode to monitor the surface chemistry of both treated and untreated porous-silicon samples before and after exposure to humid air at room temperature.
Abstract: Resistance to room temperature oxidation and control over wetting properties can be achieved by chemical modification of a porous‐silicon surface. Fourier transform infrared spectroscopy was used in the transmission mode to monitor the surface chemistry of both treated and untreated porous‐silicon samples before and after exposure to humid air at room temperature. Surface modification methods investigated include: (i) vapor‐phase silation using either hexamethyl‐disilazane or trimethylchlorosilane, and (ii) rapid thermal annealing in nitrogen, ammonia, or argon ambients. The silation treatments, carried out in the presence of trace moisture, were successful both in creating surface trimethylsilyl groups and in suppressing room temperature oxidation. Rapid thermal annealing at temperatures as low as 500°C for 30 s eliminates all silicon hydrides. Nitrided porous‐silicon layers are formed at 1100°C in either ammonia or nitrogen; in both cases the silicon nitride infrared absorption peaks scale with the porous layer thickness, indicating that the compounds are distributed throughout the porous layer.
TL;DR: In this article, the particle surface was modified by using different stabilizers in the solvent evaporation process, which resulted in coating layers up to 10 nm and distinctly increased surface hydrophilicity of the particles.
TL;DR: Data from in vitro and ex vivo experiments indicated a reduction of protein adsorption and platelet adhesion for the hydrophillic graft polymers, the extent of which was correlated to polymer graft density.
TL;DR: In this article, the surface chemical modification of poly(tetrafluoroethylene) and poly (tetraplastic polyethylene co-hexafluoropropylene) films was carried out in hydrazine gas photolyzed with ArF excimer laser irradiation.
Abstract: The surface chemical modification of poly(tetrafluoroethylene) and poly(tetrafluoroethylene‐ co‐hexafluoropropylene) films was carried out in hydrazine gas photolyzed with ArF excimer laser irradiation. The contact angle of the modified surfaces with water changed from 130° to 30° due to the reaction with hydrazine. Nitrogen on the surface was detected with x‐ray photoelectron spectroscopy, suggesting that amino groups were introduced onto the surface. In addition, on the basis of hydrophilic behavior, we succeeded in selective‐area electroless plating of nickel metal on the chemically modified surface.
TL;DR: In this paper, the effect of corona-treatment on resinous wood surfaces was studied, and it was found that the wettability of the veneers, including hardwoods, softwoods, and tropical woods increased with an increase in the degree of treatment, and the gluability increased rapidly after the initial mild treatment.
Abstract: Oxidative activation of resinous wood surfaces by a corona treatment to improve adhesive bonding was studied. It was found that the wettability of the veneers, including hardwoods, softwoods, and tropical woods increased with an increase in the degree of treatment, and the gluability increased rapidly after the initial mild treatment. To elucidate the nature of any chemical change occurring on the wood surface, the dyeing examination of the wood and its components with Schiff's reagent was made, and the results showed a higher dyeing ability for corona-treated samples compared to untreated ones, indicating that aldehyde groups increased by the corona treatment. The treatment affected the alcohol-benzene extractives, and oxidized them to produce aldehyde groups. Especially, the neutral fraction in the extractives was significantly affected. On the other hand, negligible chemical effects of the treatment on the surface modification of the wood's main components were seen. Both the untreated and corona-treated samples adsorbed basic dye to the same extent of coloration. Thus, no measurable carboxyl groups increased on the surface of the samples. It seems that an increase in the wettability of corona-treated wood veneers resulted mainly from the oxidation of the high hydrophobic surface layer of neutral fraction substances in the extractives, and from the reduction in their hydrophobicity. © 1993 John Wiley & Sons, Inc.
Patent•
30 Jan 1993
TL;DR: In this paper, a process and a device for surface modification by physico-chemical reactions with the following steps are described: a) contacting a solid surface having a crystalline or amorphous structure with a reactive, gaseous fluid (gas, gas mixture, vapour or vapour mixture) which is to interact with the surface; (b) supplying activating energy to the contact area between fluid and surface by means of ions or plasmas, in order to trigger reactions between said partners.
Abstract: The invention concerns a process and a device for surface-modification by physico-chemical reactions with the following steps: a) contacting a solid surface having a crystalline or amorphous structure with a reactive, gaseous fluid (gas, gas mixture, vapour or vapour mixture) which is to interact with the surface; (b) supplying activating energy to the contact area between fluid and surface by means of ions or plasmas, in order to trigger reactions between said partners. In order to improve such a process and device, the activating energy is supplied as ions having at least a double charge and low kinetic energy or plasma streams with a sufficient proportion of ions having at least a double charge and low kinetic energy. The kinetic energy imparted to the ions is selected so that it allows the ions to closely approach the surface atoms but no to enter the surface.
01 Jan 1993
TL;DR: In this paper, surface modification by plasma science and technology of polymer composites reinforcing fibres for composites "in situ" composites formed with polymers and thermoplastic matrices is discussed.
Abstract: Interfaces, interphases and "adhesion" - a perspective aspects of component interactions in polymer systems rheology at interfaces interactions and properties of composites - fibre-matrix adhesion measurements, adhesion composite properties relationships the role of interface at the wall in flow of concentrated composites application of surface analysis to high performance polimeric adhesives and composites some experimental methods of characterizing surface controlled interphases in glass fibre and particulate reinforced polymers - structure of silane coupling agents in solutions and on substrates control and modification of surfaces and interfaces by corona and low pressure plasma plasmas and surfaces - a practical approach to good composites plasma polimerification of acetylene - a coating technique for fibre reinforcement of composites plasma enhanced CVD of aromatics - surface treatment of carbon fibres to optimize fibre-matrix adhesion some notes on surface modification by plasma science and technology of polymer composites reinforcing fibres for composites "in situ" composites formed with polymers and thermoplastic matrices some short communications of participants - open questions on effects of fibre-matrix interactions on compound and composite properties, interface stabilization in polymer blends by means of block and graft copolymers, interfacial chemical interactions in condensation polymers and their blends, interfacial polarization and its diagnostic significance in polymeric composites, on the physical nature of interfacial layer in polymer coatings, the effect of corona modification on the composite interfaces, peculiarity of film-forming and hydrolytic decay of tin-containing polymer coatings, diffusion of metal ions in caroxylic polymer sorbents of different morphological structure, adsorption of methylene blue on PVC-DOP-natural zeolite composites, optically transparent glass fibre reinforced poly(methylmethacrylate) laminates, the effect of recycling on the properties of thermoplastic composites, carbon fibres from methane.
TL;DR: In this article, the phase transitions of finite and infinite ferroelectric systems using the Ising model in a transverse field were studied using the mean-field layer approximation and the results for the Curie temperature were expressed in terms of general determinants.
Abstract: The author studies the phase transitions of finite and infinite ferroelectric systems using the Ising model in a transverse field. The mean-field layer approximation is used and the results for the Curie temperature are expressed in terms of general determinants. The effects of surface modification are introduced through a surface exchange constant J0 and a surface transverse field Omega 0. It is shown that above a critical curve in J0- Omega 0 space, surface polarization is possible, even when there is no phase transition in the bulk. The dependence of the Curie temperature on the film thickness is obtained for two types of surface modification.
TL;DR: In this article, a remote plasma reactor, with air as the plasma gas, has been used for in-line surface modification of linear low-density polyethylene tape (LLDPE) passing 10 cm below the main plasma zone.
Abstract: A remote plasma reactor, with air as the plasma gas, has been used for in-line surface modification of linear low-density polyethylene tape (LLDPE) passing 10 cm below the main plasma zone. Line speeds of up to 0.70 m/s were tested, allowing the study of 0.014 s exposure times to the plasma. Oxygen to carbon (O/C) ratios averaging 0.11 were observed on a reproducible basis. The reactor was also used for static plasma treatment under similar experiment onditions. This allowed a comparative study of short-term (milliseconds) vs. long-term (several seconds) plasma treatment. High-resolution X-ray photoelectron spectroscopy (XPS) analysis of the treated polymer surface suggested the formation of hydroxyl (C-OH), carbonyl (C=O) and carboxyl (O-C=O) groups, even after short plasma treatment. The intensities of these components were seen to increase in approximately equal quantities with increasing O/C ratio. Water washing of polyethylene surfaces with high O/C ratios showed a loss of oxygen, apparent as a decre...
TL;DR: In this paper, the possibility of inverse gas chromatography for the surface characterization of common fillers (CaCO3, talc, SiO2,⋯) for paints and coatings is highlighted.
TL;DR: In this article, a titanium (Ti) surface was arbitrarily oxidized by a scanning tunneling microscope (STM) tip with the sample bias of more than +3 V and a dot or line pattern of oxide was fabricated on Ti with the spatial resolution of 70 nm.
Abstract: A titanium (Ti) surface was arbitrarily oxidized by a scanning tunneling microscope (STM). Oxidation of the Ti surface was induced by scanning an STM tip with the sample (Ti) bias of more than +3 V, and a dot or line pattern of oxide was fabricated on Ti with the spatial resolution of 70 nm. The results were discussed in terms of tip-induced anodization of Ti due to water adsorbed on the surface.
TL;DR: In this article, the surface modification of polypropylene (PP) in low pressure plasmas of oxygen or nitrogen was studied in detail, and the plasma configuration and processing conditions were found to be key parameters for achieving a most effective and economical plasma treatment process.
Abstract: We have studied in detail the surface modification of polypropylene (PP) in low pressure plasmas of oxygen or nitrogen. As revealed by electron spectroscopy for chemical analysis, contact angle measurements and scanning electron microscopy, the plasma ensures a quick functionalization of the PP surface with O- and N-containing chemical groups within a few seconds, while a roughening of the surface topography takes place on a distinctly enlarged time scale. The plasma configuration and processing conditions are found to be key parameters for achieving a most effective and economical plasma treatment process. When plasma treated under optimized conditions, PP shows an excellent performance in application tests ( e.g. adhesive polymer-metal bonding, adhesion of water-based coatings).
TL;DR: In this article, a non-fouling (protein-resistant) polymer surface is achieved by the covalent immobilization of polyethylene oxide (PEO) surfactants using an inert gas discharge treatment.
Abstract: A non-fouling (protein-resistant) polymer surface is achieved by the covalent immobilization of polyethylene oxide (PEO) surfactants using an inert gas discharge treatment. Treated surfaces have been characterized using electron spectroscopy for chemical analysis (ESCA), static secondary ion mass spectrometry (SSIMS), water contact angle measurement, fibrinogen adsorption, and platelet adhesion. This paper is intended to review our recent work in using this simple surface modification process to obtain wettable polymer surfaces in general, and non-fouling biomaterial surfaces in particular.
TL;DR: The fiber/epoxy resin adhesion increases after plasma treatment on ultrahigh molecular weight polyethylene (UHMW-PE) fibers by at least four times by plasma treatment.
Abstract: The fiber/epoxy resin adhesion increases after plasma treatment on ultrahigh molecular weight polyethylene (UHMW-PE) fibers. The surface modification of UHMW-PE monofilaments was studied using a combination of techniques: contact-angle measurements, SEM, and pullout tests. The results may be summarized as follows: Influenced by different plasma parameters and draw ratios of the monofilaments, the adhesion increases by at least four times by plasma treatment. Failure in the pullout tests involve rupture within a treated monofilament and the skin of it was peeled off; the degree of peeling-off is affected by different plasma treatment conditions and draw ratios of the monofilaments