Showing papers on "Surface modification published in 1981"

Process and apparatus for converged fine line electron beam treatment of objects

Abstract: This disclosure is concerned with the use of fine line converged electron beams of high aspect ratio for effecting physical, chemical, mechanical and other changes in the surface of objects, and also volume effects, including applications, for example, to semiconductor and other materials surface modification technology, annealing, welding, etching, polishing, cutting, curing and other surface and volume alteration

Interface in composite materials

Abstract: mechanical properties of the combined materials, the surface of the fibre, the nature of the fibre-resin bonding as well as the mode of stress transfer at the interface. These two last points are related to the surface properties of the fibres. The various types of bonding that may occur between fibrous materials (carbon, glass and organic fibres) and organic polymers, including the relevant theories, are briefly reviewed. In order to optimize the fibre-resin interactions, it is often essential that the interface should be chemically modified. The various possible treatments may be classified under three headings: chemical surface modification of the fibre, sizing and polymer fixation (grafting). The major factors that influence the interactions between high-performance fibres and organic resins will be established and discussed, as illustrated in a few selected examples.

Surface characterization of polyester fibers

Abstract: Fibers made from poly(ethylene terephthalate) (PET) are characterized by a hydrophobic surface with low reactivity. Modifications of the PET surface to render a higher degree of hydrophilicity and reactivity are therefore common. The modification often involves a surface layer of only a few nanometers thickness. The relatively low fraction of the modified surface layer and the fact that it is generally an organic modification on a thin curved organic substrate presents difficulties in surface analyses. Surface characterization is, however, of high importance in the evaluation of the degree and durability of a given surface modification. The paper will discuss the possibilities and the limits of using wettability studies according to the Wilhelmy method to evaluate the degree of surface modification and its permanence. Comparison between internal and external reflection Fourier-transform infrared spectroscopy will be made. The use of electron spectroscopy for chemical analysis, secondary ion mass spectrometry, laser microprobe mass analysis, and microprobe molecular optics laser examiner will be illustrated. Data will be presented from studies of model yarns and films coated with D-417 dip.

Effect of surface modification on aggregation of phospholipid vesicles.

Abstract: Phospholipid vesicles have been extensively investigated because of their usefulness as models for biological membranes and their potential application as carriers for drug delivery. However, preparations of small sonicated vesicles tend to aggregate and fuse (on storage at room temperature and at 4 degrees C), resulting in significant changes in turbidity, rate of uptake by macrophage, and proton NMR linewidths. By modification of the surface of phospholipid vesicles with charged groups such as beta-aminogalactose that extend significantly from the vesicle surface, it is possible to obtain preparations that are stable for greater than 7 days.

Polytetrafluoroethylene surface modification by impregnation with iron and manganese oxides

Abstract: Polytetrafluoroethylene (PTFE) surfaces can be modified by impregnation with Fe and Mn oxides by procedures based on Fe(CO)5 sorption in the polymer and followed by oxidation with H2O2 or KMnO4. The effect of some variables (reagent concentrations and temperature) on the amount of oxides deposited was examined. The oxides incorporated in PTFE can be only partly removed by acid cleaning. Water–PTFE contact angles and PTFE surface resistivity are altered. Electron and x-ray diffractograms of the oxides were obtained but unambiguous identification was not achieved. Transmission electron microscopy examination of surface replicas showed that impregnation with oxides which covered most of the PTFE surface was fairly uniform.

Process for the surface modification of carbon fibers

Abstract: An improved continuous hot gas surface modification process for carbon fibers is provided. The carbon fibers undergoing such processing are passed for a relatively brief residence time through a surface treatment zone to which continuously is fed nitrogen dioxide and air under conditions which have been found to produce a surprisingly effective surface modification. The resulting carbon fibers exhibit a significantly enhanced surface area and an improved ability to bond to a resinous matrix material while retaining a substantial portion of the tensile strength originally exhibited. When incorporated in a resinous matrix material, a fiber reinforced composite article of enhanced interlaminar shear strength is formed.

Surface modification of plastic material and/or product thereof

Abstract: PURPOSE: To obtain a surface of high gloss and scratch resistance, by coating on the surface of a plastic material a coating made of a polymerizable multifunctional urethane and a multifunctional oligoester followed by energy-beam irradiation to effect curing through crosslinking. CONSTITUTION: The surface of a plastic material or a product thereof is coated with a coating comprising (A) a polymerizable multifunctional urethane derived from a polyisocyanate having, in one molecule, at least three active isocyanate groups (e.g. tolylene diisocyanate) and a hydroxyl group-contg. polymerizable compound[e.g. β-hydroxyethyl (meth)acrylate]and (B) a multifunctional oligoester having, in one molecule, at least three acryloyloxy groups (and/or methacryloyloxy groups)[e.g. frimethylolpropane tri(meth)acrylate]and further, if required, (C) a photopolymerizable initiator, photosensitizer, coating ingedient(S), and organic solvent followed by energy-beam (e.g. ultraviolet) irradiation to effect curing through crosslinking, thus performing the objective surface modification. COPYRIGHT: (C)1983,JPO&Japio

Plastic material reinforced with silicon carbide

Abstract: PURPOSE:To prepare the titled composite material having excellent tensile strength, elastic modulus, impact strength, flexural strength, etc., and suitable for mechanical parts, etc., by compounding fine powder of beta-type silicon carbide to a plastic material. CONSTITUTION:100pts.wt. Of a plastic material is compounded with 20-500pts.wt., pref. 100-450pts.wt. of beta-type silicon carbide fine powder having an average particle diameter of <=1mu, pref. <=0.5mu, alpha-type silicon carbide content of <=10%, and average ratio of the major axis to the minor axis of the particle of 1.2- 1.7, and pref. obtained by converting silica and carbon at a molar ratio of 3.2-5.0 to SiC by heating at 1,650-2,100 deg.C for 0.5-3hr. The surface of the silicon carbide powder is modified with a silane coupling agent to improve the dispersibility in the plastic material and increase the bonding strength. The surface modification effect can be further improved by treating the surface with hydrofluoric acid prior to the modification, and drying in air stream at 70-250 deg.C.

Surface treatment of synthetic resin molded article

Abstract: PURPOSE:To enable uniform coating of a surface active agent to the surface of an synthetic resin molded article, to effect rapid surface modification with the surface active agent by permeating and diffusing the agent together with a plasticizer into the article, and to maintain the effect of the agent for a long period, by dissolving a surface active agent in a plasticizer, and applying the solution to the surface of a synthetic resin molded article. CONSTITUTION:A surface active agent for the modification of the surface of a synthetic resin molded article is mixed with a liquid plasticizer for the synthetic resin, and applied to the surface of the article. A plasticizer based on phthalic acid or a fatty acid esp. dibutyl sebacate, is preferable in view of its high permeability. The amount of the surface active agent is pref. 0.01-100pts.wt. per 100pts.wt. of the plasticizer. EFFECT:A surface active agent which cannot be incorporated into a resin, can be used by this process, and high modifying effect comparable to the incorporated product can be maintained for a long period.

Surface modification of synthetic resin formed article

Abstract: PURPOSE: To prepare a film, sheet, etc. having excellent anti-fogging property and transparency, by contacting a synthetic resin formed article with an aqueous inorganic sol and then with an aqueous solution containing a gelatinization agent, and drying the product. CONSTITUTION: A film, sheet, etc. of polyethylene, polypropylene, etc. is made to contact first with an aqueous sol of silica gel, water-insoluble lithium silicate sol, or alumina sol preferably having a colloidal particle content of 0.5W10wt%, and the with an aqueous solution containing preferably 1W10wt% gelatinization agent such as an acid, an alkali, a salt, ethanol, a cationic surface active agent (for silica gel and water-insoluble lithium silicate), an anionic surface active agent (for alumina sol), etc. The wet film is dried rapidly with hot air at ≥80°C. USE: Greenhouse for agricultural use. COPYRIGHT: (C)1982,JPO&Japio

Characterization of silicon dioxide surfaces by successive determinations of the solution rate. Discussion

Abstract: The successive determination of the solution rate in sodium hydroxide or in buffer solutions may serve to establish the extent of surface defects and the thickness of the more or less amorphous layer of silicon dioxide (SiO 2 ) dusts. The solution rate is a sensitive measurement for the energetic and thus crystallographic surface structure. Quartz surface modification due to thermal treatment is shown by examples. Furthermore, it is possible to produce quartz with a "pure" surface. The results of cell and animal experiments performed with crystallographic pure quartz specimens and with the same specimens coated with thin layers of amorphous silica are discussed.