Showing papers on "Surface modification published in 1985"
TL;DR: In this paper, the response of ISFETs to concentrations of ions, especially H+ ions, is determined by the type of gate surface, both the number of active surface sites and (proton) association and dissociation constants.
115 citations
TL;DR: In this paper, a combination of X-ray photoelectron spectroscopy (XPS), low energy inelastic ion scattering (LEISS), and temperature programmed desorption were used to fully characterize the composition, electronic structure and chemisorption properties of the modified surface.
99 citations
TL;DR: In this article, the tensile properties of composites prepared from treated and untreated cellulose fibers were studied before and after exposure to water and it was found that all types of fiber treatment decreased water absorption and the reduction of mechanical properties in wet conditions, but that the degradation at the fiber/matrix interface which occurs from immersion in water and drying could only be avoided through the development of covalent bonds between fiber and matrix.
Abstract: Cellulose fibers treated with different coupling agents based on trichloro-s-triazine have been evaluated in terms of their reinforcement effect on unsaturated polyesters. The treatment with coupling agents containing double bonds resulted in what we believe to be the formation of covalent bonds between fiber and matrix. This has been compared with a treatment, which can only lead to formation of close interfacial molecular contact by wetting. The tensile properties of composites prepared from treated and untreated fibers were studied before and after exposure to water. It was found that all types of fiber treatment decreased water absorption and the reduction of mechanical properties in wet conditions, but that the degradation at the fiber/matrix interface which occurs from immersion in water and drying could only be avoided through the development of covalent bonds between fiber and matrix. Scanning electron microscopy was used to study the adhesion between fiber and matrix. An explanation of the reduction of mechanical properties of cellulose-fiber reinforced polymers in wet conditions is proposed.
86 citations
TL;DR: In this article, a gas phase silanization of silicon surfaces at elevated temperatures is described, which consists of a washing and surface activation step followed by silanisation at about 0.5 −1 Nm −2 and 80 −190 °C depending on the type of silane.
82 citations
TL;DR: In this article, contact angle measurements were used to characterize the surfaces of polypropylene and glass substrates exposed to CF4, CF3H, CF 3Cl, and CF3Br plasmas.
Abstract: ESCA and contact angle measurements were used to characterize the surfaces of polypropylene and glass substrates exposed to CF4, CF3H, CF3Cl, and CF3Br plasmas. The use of both organic and inorganic substrates allowed clear distinction between treatments which led to plasma polymerization and treatments which caused grafting of functional groups directly to the substrate surfaces. CF4 plasmas were the only treatments studied which fluorinated polypropylene surfaces directly, without the deposition of a thin, plasma-polymerized film. CF3H polymerized in a plasma, while CF3Cl and CF3Br plasmas caused chlorination and bromination of polypropylene surfaces, respectively. Correlations were made between the active species present in the plasmas and the surface chemistry observed on the treated polypropylene substrates.
66 citations
TL;DR: In this paper, the surface modification of methanol-benzene mixtures and the immersional wetting properties have been investigated on nonswelling clay minerals with lamellar structure and on their organocomplexes obtained by hexadecyl-pyridinium cations (HDP+).
55 citations
TL;DR: Two coupling agents based on trichloro-s-triazine with different terminal unsaturated groups were synthesized in order to improve the bonding between cellulose fibers and an unsaturated polyester matrix as mentioned in this paper.
Abstract: Two coupling agents based on trichloro-s-triazine with different terminal unsaturated groups were synthesized in order to improve the bonding between cellulose fibers and an unsaturated polyester matrix. The products of the reactions between hydroxyl groups of cellulose and reactive species of coupling agents were analysed by Fourier-transform infrared spectroscopy (FTIR) and by elemental microanalyses. ESCA was used for surface characterization of treated fibers. The coupling agents were found to be concentrated on the fiber surface. Polymerization of styrene was carried out in the presence of treated fibers. That the unsaturated groups of the treated fibers were able to copolymrize with styrene was shown by FTIR. Further evidence of the presence of grafted polystyrene on the surfaces of the cellulose fibers was provided by ESCA measurements.
46 citations
TL;DR: In this paper, surface modified CdS semiconductors with electrically conductive polypyrrole and catalytic dispersions of transition metals (Pt, Rh, RuO2) immobilized in polystyrene films were presented.
35 citations
TL;DR: Etude de l'influence d'addition de petites quantites de copolymeres greffes par mesure de langle de contact d'une gouttelette d'eau as mentioned in this paper.
Abstract: Etude de l'influence d'addition de petites quantites de copolymeres greffes par mesure de l'angle de contact d'une gouttelette d'eau
32 citations
TL;DR: A derivative of vitamin B12 containing a 3,5-diaminobenzoyl group in the c side chain has been synthesized and used as the amine component in the formation of an optically active cross-linked epoxy-polymer surface modification of carbon electrodes.
Abstract: Surface Modification of Carbon Electrodes by Polymers Consisting of Epoxy Resins and a Derivative of Vitamin B12
A derivative of vitamin B12 containing a 3,5-diaminobenzoyl group in the c side-chain has been synthesized It was used as the amine component in the formation of an optically active cross-linked epoxy-polymer Surface modification of carbon electrodes (basal plane graphite and carbon felt) has been achieved by impregnating them with solutions of the monomers followed by thermal curing at 120°C Electrochemical responses of the Co(II)/Co(I) redox system from sub-mono to multilayer coverages have been observed The polymer exhibits catalytic activities typical for monomeric vitamin B12 as shown by spectroscopic and electrochemical techniques Polymermodified electrodes with large specific surfaces have been used in organic electrosynthesis, ie the exclusive formation of valeronitrile by reductive cross-coupling of ethyl iodide and acrylonitrile
30 citations
TL;DR: In this article, it was found that aqueous sodium hydroxide can effectively activate wood surfaces to give strong dry autohesive bonds, but only low wet strength was obtained.
Abstract: Current knowledge of wood surface characteristics and surface modification are briefly reviewed and the postulated effects of chemical activation are summarized. It was found that aqueous sodium hydroxide can effectively activate wood surfaces to give strong dry autohesive bonds, but only low wet strength was obtained. However, excellent dry and wet wood bond strengths, equivalent to phenol-formaldehyde bonded samples, were obtained when methylolated lignin was used in combination with 3N sodium hydroxide activation. Several mechanisms of base activation are suggested, including enhanced wood surface contact and reactivity.
TL;DR: The surface Mo atom oxidation states for a series of chemically modified Mo(100) surfaces have been measured by XPS as discussed by the authors, and the surface adsorbates used were boron, carbon, oxygen, carbon monoxide and carbon dioxide.
Patent•
01 Feb 1985
TL;DR: In this article, a surface modification of oriented polymeric film is described, which involves subjecting the film surface to at least one short pulse of intense electromagnetic radiation to enhance the heat seal adhesion.
Abstract: A process for surface modification of oriented polymeric film is disclosed. The process, applicable to polyesters, polyolefins, and polyamides, involves subjecting the film surface to at least one short pulse of intense electromagnetic radiation. Such surface treatment enhances the heat seal adhesion of the oriented polymeric film.
Patent•
04 Dec 1985
TL;DR: In this paper, a method of modifying a surface of a soft contact lens to make the lens resistant to soiling is described, which consists in initiating a reaction between the unhydrated lens surface containing carboxylic acid or alcohol moieties and agents capable of reacting with carboxyl acid and alcohol, in order to produce a surface which then either has a hydrophobic coating, a nonionic hydrophilic coating or is charged.
Abstract: The present invention relates to a method of modifying a surface of a soft contact lens to make the lens resistant to soiling. The method comprises initiating a reaction between the unhydrated lens surface containing carboxylic acid or alcohol moieties and agents capable of reacting with carboxylic acid or alcohol moieties in order to produce a surface which then either has a hydrophobic coating, a nonionic hydrophilic coating or is charged.
TL;DR: The reactivity of polymers of different composition towards amino acid derivatives and model proteins, such as catalase and ribonuclease-A, is described and extensive crosslinking between polymer and enzymes takes place, yielding insoluble adducts.
Abstract: Surface modification of enzymes for a potential use in therapy was obtained with a new type of tailor-made copolymers ofNacryloylmorpholine andN-acryloxysuccinimide. The first monomer was designed to confer solubility on the polymer, whereas the second was used to give it reactivity toward protein amino groups. The reactivity of polymers of different composition towards amino acid derivatives and model proteins, such as catalase and ribonuclease-A, is described. Water soluble and catalytically active enzyme derivatives were obained using copolymers prepared with a mixture of N-acryloxysuccinimide andn-acryloylmorpholine in a 1:99 molar ratio. At increasing molar ratio (3:97, 10:90) extensive crosslinking between polymer and enzymes takes place, yielding insoluble adducts.
TL;DR: In this paper, the effect of Energetic Particles Irradiation on Vinyl Polymers was investigated using two types of reactors, which were a tubular type and a gas flow type.
Abstract: Plasma etching of polymeric material and plasma polymerization of monomers were performed by using two types of reactors, which are a tubular type and a gas flow type reactor. Phenomena of deposition and ablation of organic materials in low temperature plasma are discussed in relation to the practical processes. INTRODUCTION Plasma chemical processes of organic material in low temperature plasma are given attention in various fields of technical development. The principal processes are organic thin film coating, surface modification and etching of polymeric substrate. The processes are performed under irradiation of electrons, ions, protons and activated neutral particles in a wide range of energy level. Therefore, the phenomena in the processes are usually complicated and the process is difficult to be regulated. However, several kinds of applications were attained because of technical developments of evacuation systems, discharge power sources, diagnostics and surface analysis. In this study, several experiments on plasma etching of polymeric material and plasma polymerization were performed by using two types of reactors, which were a tubular type and a gas flow type. The interaction between plasma and polymeric materials in low temperature plasma will be discussed. Recent results of application will be also introduced. GENERAL FEATURES OF PLASMA CHEMICAL PROCESSES FOR ORGANIC MATERIALS Effect of Energetic Particles Irradiation On Vinyl Polymers It is well known that the plasma chemical process is affected by chemical propertst of polymeric materials under the plasma irradiation. Lawton et al.(ref. 1 and 2) classified conventional vinyl polymers into two groups as shown in Table 1: those that become degraded under high energy irradiation and those that become cross-linked. According to Miller et al., there is a simple correlation of radiation effect and chemical structure of vinyl polymers which have a following generalized structure(ref. 2).
TL;DR: In this paper, X-ray photoelectron spectroscopy was used to study the surface chemistry of wool fibres and showed that complete coverage of the wool-fibre surface does not occur even though the average thickness of the polymer overlayer is about 1000 A (100 nm).
Abstract: The application of X-ray photoelectron spectroscopy to the study of the surface chemistry of wool fibres clarifies some aspects of the role of the cystine disulphide bond. The sensitivity of the electron-binding energy of the S(2p) orbitals to the sulphur oxidation state provides information about the extent of surface modification following two different oxidizing treatments using (a) dichloroisocyanuric acid, and (b) hypochlorous acid (‘Kroy’ chlorination). Interaction of a wool surface with a polymer, Hercosett 125, which is the basis of a shrink-resistant treatment, shows that complete coverage of the wool-fibre surface does not occur even though the average thickness of the polymer overlayer is about 1000 A (100 nm).
TL;DR: In this article, electron spin resonance (ESR) spectra of polyethylene and polypropylene composites were studied under various conditions, depending on the preparation technique used and on the sample age.
TL;DR: In this article, an electrochemical pretreatment of glassy carbon electrodes was shown to enhance significantly the sensitivity of the electrodes for the detection of timolol and oxprenolol, but reduce slightly the sensitivity to prenalterol.
Abstract: Electrode surface modification by electrochemical pretreatment of glassy carbon electrodes was shown to enhance significantly the sensitivity of the electrodes for the detection of timolol and oxprenolol, but reduce slightly the sensitivity to prenalterol. This method may permit the detection of exprenolol and timolol with increased sensitivity, or may allow their detection at lower applied potentials than is presently possible. Electrode surface modification may prove to be a valuable aid to the detection of compounds that are considered to be outside the practical limits of electrochemical detection.
Patent•
11 Jul 1985
TL;DR: In this article, a modified fused spherical silica, having improved surface activity and suitable to fillers for resin based semiconductor sealing compounds, was produced by subjecting fused spherical Silica having a specific average particle diameter to treatment of mechanochemical reaction by powerful shearing operation.
Abstract: PURPOSE: To produce modified fused spherical silica, having improved surface activity and suitable to fillers for resin based semiconductor sealing compounds, by subjecting fused spherical silica having a specific average particle diameter to treatment of mechanochemical reaction by powerful shearing operation. CONSTITUTION: Fused spherical silica having within 1W100μ average particle diameter range is subjected to treatment of mechanochemical reaction using a ball mill, etc., by powerful shearing operation. Thereby, a BET specific surface area of at least 3 times or more based on the theoretical specific surface area exhibited by a true sphere of the particle diameter is given to the silica, and silanol groups are formed on the surface thereof to activate the particle surface. As another mode, the surface is treated with an alcohol or organosilicon compound, hydrophobized and modified. Therefore, the surface modification of the fused spherical silica particles of high purity containing ≤1ppb α-ray radioactive materials, e.g. U or Th, can be carried out. COPYRIGHT: (C)1987,JPO&Japio
Patent•
06 Nov 1985
TL;DR: In this paper, the surface of a polymeric base is subjected to glow discharge treatment in a vacuum of 0.01-several Torr in a nonpolymerizable gas atmosphere.
Abstract: PURPOSE:To obtain a polymeric base which scarcely changes with time, by forming a thin polymer film on the surface of a polymeric base subjected to glow discharge treatment by applying thereto a specified polymer liquid. CONSTITUTION:The surface of a polymeric base is subjected to glow discharge treatment in a vacuum of 0.01-several Torr in a nonpolymerizable gas atmosphere. A polymerizable liquid or dissolved monomer is subjected to glow discharge treatment in an evacuated vessel and post-polymerized under exclusion of oxygen to form a polymer. The pressure in the vessel is increased to atmospheric pressure and, if desired, a solvent is added thereto to form a liquid product. This liquid is applied to the surface of the polymeric base subjected to the blow discharge treatment and dried to form a thin polymer film on its surface. EFFECT:The surface of a polymeric base can be reformed to hydrophilic, so that its printability, dyeability, antistatic property, adhesion, biocompatibility, etc. can be improved.
Patent•
25 Feb 1985
TL;DR: In this paper, surface modification of polyester material is obtained by contacting the material in substantially non-crystallized form with a noncrystallizable oligomer, which has ester linkages and is prepared from a reaction mixture which includes at least one polyol having a functionality greater than three and selected from the group consisting of pentaerythritol, low molecular weight polymers of polymers, glycerol, and mixtures thereof.
Abstract: Surface modification of polyester material is obtained by contacting the material in substantially non-crystallized form with a non-crystallizable oligomer. The oligomer has ester linkages and is prepared from a reaction mixture which includes at least one polyol having a functionality greater than three and selected from the group consisting of pentaerythritol, low molecular weight polymers of pentaerythritol, glycerol, low molecular weight polymers of glycerol and mixtures thereof. After contact with the oligomer, the polyester is crystallized. The modified polyester material exhibits improved properties such as hydrophilicity and/or adhesive bonding.
TL;DR: In this paper, the surface modification of mica has been studied to determine how the surface modifications of the mica influences flexural strength and fracture toughness of reinforced mica reinforced cement composites.
TL;DR: In this paper, the authors discuss the effect of gender stereotypes on the performance of the human body and its ability to adapt to gender in the context of gender discrimination in the workplace.
Abstract: 化学構造の異なる種々のモノマー単位を有する幹成分と,単分散ポリスチレンの枝成分とからなる構造の明確なグラフト共重合体をマクロモノマー法を用いて合成し,ポリスチレン単独重合体中へ少量添加して溶媒成膜し,その表面特性の変化を調べ単独重合体の表面改質剤としての応用を検討した。その結果,グラフト共重合体の幹成分の化学構造および添加濃度に依存して成膜試料の自由表面,基質側表面のぬれ特性がそれぞれ大幅に変化すること,また光電子スペクトルで検出されたグラフト共重合体中の幹成分の表面析出量はバルク領域の濃度にくらべていちじるしく高く接触角の結果とよく対応していること,さらに幹成分の表面析出量はグラフト共重合体の枝成分の分子量にも依存し,幹成分と枝成分とのバランスの点で最適なグラフト共重合体の構造が存在することが示された。これらの結果から,種種の機能性官能基を有するグラフト共重合体を用いて高分子単独重合体表面の修飾が可能であることがわかった。
01 Jan 1985
TL;DR: In this paper, the authors describe surface coatings formed in a plasma by the fragmentation of "monomer" molecules, the formation of reactive sites on surfaces (including newly formed plasma polymer) in contact with the plasma, and the reaction of monomer fragments with the surface and each other.
Abstract: Plasma polymers are surface coatings formed in a plasma by the fragmentation of “monomer” molecules, the formation of reactive sites on surfaces (including newly formed plasma polymer) in contact with the plasma, and the reaction of monomer fragments with the surface and each other. Such films are formed in a glow-discharge, a plasma (electrically neutral ionized gas) formed (and sustained) by an electric field in a partial vacuum (less than 10 Torr pressure). As a consequence of the low pressure. electrons are characterized by electron temperatures of 10,000° C, average electron energies of 1–10 eV and non-equilibrium with gas molecules.1 The temperature of the latter is therefore close to ambient.
TL;DR: Pulsed laser annealing and ion beam mixing have been used as surface modification techniques to enhance the physical properties of polycrystalline α-SiC as discussed by the authors, which can induce unique microstructural changes at the SiC surface which are not attainable by conventional thermal treatments.
Abstract: Pulsed laser annealing and ion beam mixing have been used as surface modification techniques to enhance the physical properties of polycrystalline α-SiC. Thin Ni overlayers (20 nm - 100 nm) were evaporated onto the SiC surface. The specimens were subsequently irradiated with pulses of a ruby or krypton fluoride (KrF) excimer laser or bombarded with high energy Xe+ or Si+ ions. Both processes are non-equilibrium methods and each has been shown to induce unique microstructural changes at the SiC surface which are not attainable by conventional thermal treatments. Under particular (and optimum) processing conditions, these changes considerably increased the mechanical properties of the SiC; following laser irradiation, the fracture strength of the SiC was increased by as much as 50%, but after ion beam mixing, no strength increase was observed. High resolution cross-section transmission electron microscopy (X-TEM), scanning electron microscopy (SEM), and Rutherford backscattering techniques were used to characterize the extent of mixing between the Ni and the SiC as a result of the surface modification.