Fluorocarbon Resin Research Articles

Controlled synthesis of NaYF4 nanoparticles and upconversion properties of NaYF4:Yb, Er (Tm)/FC transparent nanocomposite thin films

Monodisperse oleic acid stabilized pure NaYF4 nanoparticles with controlled size and shape have been successfully synthesized by changing the initial reaction temperature. Transparent nanocomposite thin films consisting of NaYF4:Yb, Er (Tm) upconverting nanoparticles (UCNPs) and fluorocarbon resin (FC) are deposited on the slide glass by dip-coating method. The results show that these nanocomposite thin films exhibit intense green and blue upconversion photoluminescence under 980nm laser excitation and higher transparency than blank substrate. The NaYF4:Yb,Er (Tm) nanoparticles and NaYF4:Yb,Er (Tm)/FC nanocomposite thin films have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), SEM/back-scattered electron (BSE), atomic force microscopy (AFM), UV–Vis spectrophotometer (UVPC), and photoluminescence (PL) spectra. These nanocomposite thin films can be potentially used in solar cells field.

Fabrication and optical properties of self-assembled films with micro needlelike arrays under magnetic field

The films with micro needlelike arrays, made of cobalt powders and fluorocarbon (FC) resin, were fabricated by self-assembly under the magnetic field. It is convenient to make micro arrays, and structures retain when external field is removed. The self-assembled films, treated under different field strength, were characterized by the stereoscopic microscope and scanning electron microscopy in detail. The density and shape of arrays varied as strengths of magnetic field increased. When the magnetic field reached to maximum, the space between two “needles” was 200–300 μm, the diameter of the middle of “needles” was about 20 μm, and the height of the arrays was 1–1.2 mm. The reflectance of the films with the needlelike arrays was lower than that of the films without magnetic field applied in the range of 300–2500 nm.

UV Ageing Test and EIS Study of Fluorocarbon Resin Coatings on Galvanized Sheet

The aim of this study is to study the protection performance of fluorocarbon resin coatings on galvanized sheets with electrochemical impedance spectra(EIS) and scanning electron microscopy (SEM) for UV ageing to simulate nature environment. The results indicated that impedance of the coatings acted as a capacitive character at the early UV ageing stage. the diffusion impedance was shown in low-frequency range, which was attributed to the self-healing effect of the chromate layer to the metal interface. After 2000 hours of ageing in the UV chamber, there is a low impedance values in the impedance spectra. Taking into account defects were found on the film surface on SEM picture, it is easy that the outside corrosive substances meet metal substrate through the coating at the defects.

Superhydrophobic Coatings Prepared by Micro/nano Particles Mixed with Fluorocarbon Resin

In this paper, single and multilayer superhydrophobic composite coatings, based on fluorocarbon resin and micro-tourmaline and nano-TiO2powers, were prepared by conventional air spray method. The tourmaline and TiO2particles were modified by fluoroalkylsilane. The wettability and marine corrosion of the coatings surfaces were investigated respectively by contact angle measurement and Electrochemical Impedance Spectroscopy (EIS) method, and their morphology was examined by Scanning Electron Microscopy (SEM). The results showed that the water contact angle of coatings was mainly controlled by the mass ratio of the fluorocarbon resin and particles. The contact angle increased with the increase of particle concentration, which reached about 156° when the mass ratio of the particles and fluorocarbon resin was 2:1 for single and multilayer composite coatings, but the impedance valve of the multilayer is higher than that of the single layer.

Investigation into PEFC Characteristics Using Four-Layer Electrode Catalyst

Water management of the catalyst layer in a polymer electrolyte membrane fuel cell was improved by focusing on the three-phase boundary. To fabricate the cathode catalyst layer, carbon-support with catalyst and fluorocarbon resin were mixed and heat-treated at the melting temperature of fluorocarbon resin. The transmission electron microscopy images of this electrode catalyst showed that the surfaces of the catalyst particle and of the carbon-support were partly coated by thin film of melted fluorocarbon resin. Ionomer electrolyte material was added to this electrode catalyst, and an electrode catalyst with a four-layer structure was fabricated. The durability at 50{degree sign}C of a single cell using the four-layer electrode catalyst as the cathode was examined. The deterioration rate was lower than that using the conventional three-layer electrode catalyst. In addition, a load change test at 50{degree sign}C, and a durability test at room temperature gave good results.

Investigation into polymer electrolyte membrane fuel cell characteristics using four-layer electrode catalyst

The use of auxiliary power and the cost of using main power decrease when the reactive gas is applied at low humidity for the operation of polymer electrolyte membrane fuel cells. The electrolyte membrane and the three-phase boundary of the electrode need to be improved to maintain this low humidity. We carried out a study of the electrode catalyst at low humidity in order to improve the cathode catalyst. Carbon support with a catalyst and fluorocarbon resin were mixed and then were treated at the melting temperature of fluorocarbon resin to fabricate the cathode-electrode catalyst layer. The transmission electron microscopy images of this electrode catalyst revealed that the surfaces of the catalyst particle and the carbon support were partly coated with a thin film of melted fluorocarbon resin. Ionomer electrolyte material was added to this electrode catalyst, and an electrode catalyst with a four-layer structure was fabricated. The durability of this four-layer electrode catalyst being operated at low humidity (42% relative humidity on the anode and the cathode) was evaluated by using a cell that contained the catalyst. The results demonstrated that the rate of deterioration was smaller than that of a conventional three-layer electrode catalyst. In addition, the load change test to assess the durability of the cell (current range between 75 and 600 mA cm−2) produced good results.

Coupled Measurements of Water Content and Electrical Conductivity in Dielectrically Lossy Clay Slurry Using a Coated TDR Probe

ABSTRACT Although time domain reflectometry (TDR) has been widely accepted as a non-destructive in-situ method with high reliability, the effective use of TDR for water content (w) and electrical conductivity (EC) measurements in clay slurry has not been established. We developed a Teflon-coated (TC) probe with a 0.05-mm thick fluorocarbon resin coating, and conducted a calibration experiment for kaolinite slurry to indicate its applicability to the measurements. The TC probe could estimate w from the observed effective dielectric constant (eeff) in the range of w≥47% with a ±6% error range. The eeff includes dielectric constant of two components: material under test (em) and coating material (etef). The relationship between eeff and w for this particular probe design cannot be directly applied to other coated probes because each probe has its own specific dielectric characteristic. We defined a function expressing the characteristic, that is eeff vs. em, according to the testing in various fluid media. By applying the function, the observed data sets of eeff were transformed for a soil specific value (em). Owing to the sufficient agreement of the em values with those for the uncoated probe, we obtained the data sets of em vs. w and its empirical expression for kaolinite slurry.

Effect of casting atmosphere on the shear bond strength of a ceramic to Ni-Cr and Ni-Cr-Be alloys

The success of metal-ceramic restorations depends on an optimal bond between metal and ceramic. This study evaluated the effect of 3 casting atmospheres on the metal-ceramic bond strength (MCBS) of 2 Ni-Cr alloys, with beryllium (Fit Cast V) and without beryllium (Fit Cast SB). Sixty acrylic resin patterns (8 mm long and 5 mm diameter) were obtained using a fluorocarbon resin matrix. Wax was used to refine the surface of acrylic resin patterns that were invested and cast in an induction casting machine under normal, vacuum, and argon atmospheres at a temperature of 1340 degrees C. The castings were divested manually and airborne-particle abraded with 100-microm aluminum-oxide. Ten castings were obtained for each group. The IPS Classic V ceramic was applied (2 mm high and 5 mm diameter). The shear bond strength was tested in a mechanical testing machine with a crosshead speed of 2.0 mm/min. The MCBS data (MPa) were subjected to 2-way analysis of variance (alpha=0.05). There was no statistically significant difference (p>0.05) between the alloys or among the casting atmospheres. Within the limitations of this study, it may be concluded that the presence of beryllium and the casting atmosphere did not interfere in the MCBS of the evaluated metal-ceramic combinations.

Tribological Behavior and Surface Characteristics of Metal Microtube in Flaring Test

In this study, the effect of tool asperity and the lubrication condition on tribological behavior, inner surface characteristics and deformation limit of metallic microtube in flaring test were investigated experimentally. The microtube used in this experiment is stainless steel (SUS 316L) and has a 500 μm outer diameter and 50 μm thickness. The flaring tests of the microtube using a conical tool were conducted under dry and two kinds of lubricated-contact conditions as well as different tool surface roughnesses. As a result, it is found that the flaring load and deformation limit of the microtube increase when using a rougher tool. In addition, a spray-type fluorocarbon resin, as a solid lubricant, decreases the above characteristics, but lubrication oil, as a liquid lubricant, exhibits different behavior. Meanwhile, the surface roughnesses of the inner surface of the microtube along axial and circumferential directions reduce when using a rougher tool. From these results, the surface smoothing mechanism of the microtube in the flaring test and the influencing parameters on tribological behavior are discussed.

Effect of Washing and Subsequent Heat Treatment on Water Repellency and Mechanical Properties of Nylon 6, Triacetate and Silk Fabrics Treated with Hydrocarbon Resins

It is commonly known that water repellency of the fabric treated with fluorocarbon resin brings about a decrease by the washing and recovers by the subsequent heat treatment. In this article, effect of the water repellency was investigated on the nylon 6, triacetate and silk fabrics treated with hydrocarbon and silicon resins. Hydrocarbon and silicon resins have been widely used in the textile finishing as the softening and water proofing agents. The fabrics were treated with hydrocarbon resins, Paragium JQ and RC (Ohara Paragium Chemical Co.) and a silicon resin, Poron MR (Shinetsu Chemical Co.), and then washed and subsequently heat treated. Although the water repellency increased by the resin treatment, it decreased by the washing apparently and recovered a little by the heat treatment. The effect of the heat treatment was small comparing with that of the fluorocarbon resin. Furthermore, as a mechanical property of the treated fabric, KES shearing and bending hysteresis parameters, modulus and hysteresis width of the hydrocarbon resin-treated nylon 6, triacetate and silk fabrics decreased by the heat treatment after washing. Therefore, the treatment is effective at improving the softening of the fabric in water repellent finish.

Effects of dispersants on dispersion of carbon nanotubes and properties of fluorocarbon resin nanocomposites

Effects of dispersants on dispersion of carbon nanotubes and properties of fluorocarbon resin nanocomposites

Development of High Corrosion Resistant Mo<sub>2</sub>NiB<sub>2</sub> Boride Base Cermets for Plastic Injection Molding Machine Parts

Injection molding of corrosive super engineering plastics and engineering plastics with various fillers is conducted under severe conditions and causes corrosion and wear problems. Hence, in orde to apply Mo2NiB2 boride base cermets into plastic molding machine parts, the effects of V substitution for Cr on the mechanical properties, corrosion resistance and microstructure of Ni- 5.0B-51.0Mo-(17.5-X)Cr-XV (mass%) model cermets were investigatied. Both transverse rupture strength (TRS) and hardness increased monotonically with increasing V content and reached 2.94GPa and 87.2RA at 10.0%V, respectively. The improvements of TRS and hardness were attributed to microstructural refinement. The excellent corrosion resistance for a molten fluorocarbon resin was obtained up to 5.0%V.

高強度高耐食性射出成形機用Ｍｏ２ＮｉＢ２系硬質合金の開発

Recently, super engineering plastics containing various kinds of fillers and a very corrosive fluorocarbon resin are increasing in the plastic injection molding. Injection molding machine parts used in severe molding conditions requires excellent mechanical properties and corrosion resistance of the part materials. In this paper, in order to investigate the applicability of Mo2NiB2 base cermets, having high corrosion resistance, into injection molding machine parts, the mechanical properties and corrosion resistance of the cermets with the composition of Ni-5.0mass%B-51.0mass%Mo-(17.5-X)mass%Cr-Xmass%V (X=0∼10.0) cermets were studied. Transverse rupture strength (TRS) and hardness of the cermets increased monotonically with increasing V content and reached the maximum values of 2.94GPa and 87.2HRA at 10.0mass%V (X=10.0), respectively. The excellent corrosion resistance for a molten fluorocarbon resin together with relatively high TRS was obtained up to 5.0mass%V (X=5.0).

The Degradation Prevention of Resin Materials for Semiconductor Manufacturing Equipment by Applying the Ultra-High Purity Gas Supply Technology

The production (molding) guideline to realize ultraclean resin components for semiconductor equipment has been established. In this paper, we focused on the degradation behavior of resin materials for the purpose of reducing low-molecular-weight volatile contaminants concentration in resin components because the molding is carried out at high temperature and low-molecular-weight volatile contaminants are produced by thermal degradation. It was clarified that the oxygen concentration in high temperature molding environment is required to be below 1 ppm. And as the contact surface of the thermal degradation prevention for the resin material, the following surface materials are effective. 1) Passivation surface for a hydrocarbon resin. 2) Ni (nickel) surface for a fluorocarbon resin. As a result, we found the degradation prevention of the resin material can be realized until around 400°C although the degradation was observed even under 200 °C if using current process condition. Therefore, low-molecular-weight volatile contaminants can be drastically reduced from resin components by using the guideline and ultraclean semiconductor equipment must be realized.

458 フッ素樹脂のマイクロ押印加工 : 負荷/除荷および加熱/冷却条件の転写精度への影響(切削・研削・研磨加工II,オーガナイズドセッション,人体のコンピュータモデルの作成とその応用,特別講演)

458 フッ素樹脂のマイクロ押印加工 : 負荷/除荷および加熱/冷却条件の転写精度への影響(切削・研削・研磨加工II,オーガナイズドセッション,人体のコンピュータモデルの作成とその応用,特別講演)

Effect of Washing and Subsequent Heat Treatment on Surface Characteristic of Glass Fabric Treated with Fluorocarbon Resin

It is well known that water repellency of the fabric finished with perfluorocarbon resin lowers by washing

Change of Surface Characteristic of Cotton and Polyester Fabrics Treated with Silicone Resin by Washing and Subsequent Heat Treatment

It is commonly known that water repellency of the fabric treated with fluorocarbon resin brings about a decrease by the washing and recovers by the subsequent heat treatment. In this article, effect of the water repellency was investigated on the cotton and polyester fabrics treated with silicone resin. Silicone resin has been widely used in the textile finishing as the softening and water proofing agents. The fabrics were treated with a silicone resin, Poron MR (Shinetsu Chemical Co.) and then washed and subsequently heat treated. Although the water repellency increased by the resin treatment, it decreased by the washing apparently and recovered a little by the heat treatment. The effect of the heat treatment was small comparing with that of the fluorocarbon resin. Furthermore, in order to investigate the change of the surface chemical composition of the fabric, ESCA analysis was carried out. The O1s and Si2p intensities were almost unchanged by the washing and following heat treatment. The Si2p showed also the same tendency. As a mechanical property of the treated fabric, KES shearing and bending hysteresis parameters, modulus and hysteresis width of the silicone resin treated cotton and polyester fabrics decreased by the heat treatment after washing. Therefore, the treatment is effective at improving the softening of the fabric in water repellent finish.

Flexural properties of denture base polymers reinforced with a glass cloth–urethane polymer composite

Objectives. A newly designed light-cured reinforcement made from urethanemethacrylate oligomer and woven glass cloth has orthotropic anisotropy. This is produced for incorporation into the outermost position under the greatest tension in denture base resins. In this study, the flexural properties of self-, heat-, and light-curing reinforced resins were determined. Methods. The silanized glass cloth was soaked in urethanemethacrylate oligomer containing camphorquinone and 2-(dimethylamino)ethylmethacrylate. It was sandwiched between two pieces of polyethylene film and pressed to form a reinforcement sheet 0.3 mm in thickness, which was light-cured and prepared using four different surface conditions: with or without the polyethylene film and with or without a bonding agent. The reinforcement sheet was fixed in a fluorocarbon resin mold 3 mm in thickness, which was filled with self-, heat-, or light-curing resin and cured. The cured laminated plate was cut for flexural testing (40×7×3 mm 3). A three-point flexural test was carried out at a crosshead speed of 2 mm/min and a span length of 30 mm. In this study, the glass fiber content was measured at percentages by weight because it was not possible to determine accurately the volume of the various polymers. Results. The baseline flexural strengths of the self-, heat-, and light-curing resins were 76.2, 68.6, and 55.6 MPa, respectively, and these values were increased to 271.7, 216.4, and 266.5 MPa by the reinforcement sheet. The baseline flexural moduli of self-, heat-, and light-curing resins were 2.0, 2.4, and 2.1 GPa, respectively. These values were increased to 7.2, 5.1, and 6.6 GPa by the reinforcement sheet. SEM photographs revealed good impregnation of the glass fiber within the polymer matrix. Significance. The differences in the flexural strengths and flexural moduli of the control and reinforced specimens were significant ( p<0.01).

Washing Durability of Cotton Coated with a Fluorinated Resin: An AFM, XPS, and Low Frequency Mechanical Spectroscopy Study

The evolution, during laundering, of mechanical, chemical, and morphological prop erties of cellulose fibers covered with a fluorocarbon resin is studied using a combination of low frequency mechanical spectroscopy (LFMS), x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). From this study of the roughness and surface composition of the film covering cellulose fibers, new explanations are proposed for the decrease in water and oil repellency with washing, and its partial recovery with subsequent heat treatment such as ironing. The observed phenomena involve de-wetting and re wetting of the fluorinated polymer on the cellulose surfaces, inducing a modification of adhesion mechanisms between the fluorocarbon polymer and the cellulose fibers and the formation and/or destruction of fluorinated polymer bridges (matrix or ligand effect) between the fibers.

Applying a Nonformaldehyde Crosslinking Agent to Improve the Washing Durability of Fabric Water Repellency

1,2,3,4-Butanetetracarboxylic acid (BTCA) is confirmed to be an effective crosslinking agent with sodium hypophosphate (SHP) catalyst for washing durability improvement of cotton fabrics treated with fluorocarbon resin. By FTIR analysis, hydroxyl groups (—OH) are confirmed as a water repellency agent, so the resin can be theoretically crosslinked with the surface of the cotton fibers. The water repellency of the sample treated with fluorocarbon resin and 8% BTCA is much higher than the sample treated only with fluorocarbon resin. This kind of difference can be seen especially after fifty washing cycles and subsequent heat treatments, ESCA analysis confirms that the F/O ratio on the fabric surface changes dramatically after fifty washing cycles and subsequent heat treatment. The F/O of the sample treated with fluorocarbon resin and 8% BTCA is almost twice that of the fabric treated with fluorocarbon resin only. Crosslinks can restrict F loss and transfer into the inner part of the fibers. At the same time, this kind of treatment can effectively improve the crease resistance of cotton fabrics.