Recovery of fluorocarbons in Japan as a measure for abating global warming

The objective of this study is to evaluate the potential for recovering fluorocarbons as measures for the abatement of global warming. In this study, we focused on the three different kinds of fluorocarbons: CFCs, HCFCs and HFCs, and targeted refrigerant use because of the availability of relevant data. We first estimated future fluorocarbon emissions from the targeted appliances; we next compared those emissions in the units of CO₂ equivalent to the level of CO₂ emissions in 1990 from a quantitative point of view. As the result of this study, it was found that fluorocarbon emissions in 1999 and 2010 would be equal to approximately 7 and 3% of the level of CO₂ emissions in 1990 respectively. Moreover, if we implement a 100% recovery rate in every recovery route, we can reduce a large amount of emissions which correspond to approximately 2–5% of the level of CO₂ emissions in 1990, even if we take into account the energy-related CO₂ emissions by the transportation and decomposition of fluorocarbons.     

Experimental and Calculational Studies of the Interactions of BF3 with Fluoroethers

BF₃ was co-condensed with (C₂H₅)₂O, (CF₃CH₂)₂O, and (C₂F₅)₂O in excess argon at 15 K. Infrared spectra of the matrices showed a definite Lewis acid-base interaction between BF₃ and diethyl ether; a weak but definite interaction with bis(2,2,2,-trifluorodiethyl)ether, and no observable interaction with perfluorodiethyl ether. Molecular orbital (MO) calculations complemented the experimental observations by revealing that fluorine atoms on the ethers decreased electron localization about the oxygen atom. Thus, the experimental data and MO calculations indicated a clear trend between strength of interaction with BF₃ and the degree of ether F substitution. The implications of the results for commercial perfluoro ether lubricant/metal oxide surface interactions are discussed.     

Preparation of cultured mammalian cells for transmission and scanning electron microscopy using aclar film

Common methods for the preparation of cultured cells for concurrent light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are not completely satisfactory. This article describes how we grow mammalian cells on plastic disks made from Aclar film. Aclar is a transparent fluorinated-chlorinated thermoplastic that contains no volatile components and is, for all practical purposes, chemically inert. Cells adhere to it readily and remain attached after fixation, dehydration, and critical-point drying or embedding. The film also accepts heavy metal coating by ionic bombardment and is extremely stable in the vacuum of the SEM. LM observations are unhindered by Aclar, since the film is as transparent as glass. Fluorescence microscopy is possible with this film, since it exhibits no detectable autofluorescence. During SEM observation, the film has great dimensional stability, and the cells and heavy metal coating remain attached to the Aclar even under high-resolution operating conditions. TEM processing of specimens grown on Aclar is simplified by the fact that Aclar does not stick to the epoxy resins used in EM. Furthermore, Aclar is easily sectioned and does not damage knives used in ultramicrotomy. The use of Aclar film considerably simplifies the preparation of cultured cells for all types of microscopy. This method is particularly useful in correlating surface features between SEM and TEM observations.     

A Surface Effect Associated with the Use of Oils Containing Zinc Dialkyl Dithiophosphate

It is shown that the operation of engines on crankcase oils containing appreciable amounts of zinc dialkyl dithiophosphate can increase the small-scale roughness of the lifter-foot surfaces. In addition, the small-scale roughness can be reduced by subsequent operation of the same engine parts on oils containing no zinc dialkyl dithiophosphate. This change in roughness coincides with a change in reflectivity that can be detected visually.

A similar effect of the additive has been demonstrated in a bench test machine. The increase in roughness which accompanies the operation on the additive-treated oil occurs rapidly and is maintained to high contact loads although some smoothing may occur at high loads.

The evidence suggests that the change in roughness results from a reaction of additive decomposition products with the metal surface. The mechanism responsible, however, is not completely understood.     

Computational Chemistry of Soluble Additives for Perfluoropolyalkylether Liquid Lubricants

Computational chemistry has been applied in a practical manner to a perfluoropolyalkylether (PFPAE) liquid lubricant research and development program. Additives have been previously shown to be effective in a PFPAE liquid lubricant candidate gas turbine engine oil base fluid as oxidation inhibitors/metal deactivators, lubricity additives and antirust additives. In this effort, low energy configuration computer models of the base fluid and of selected additives were created. Simulated docking of the additive molecules in the base fluid media, onto low carbon steel and onto iron oxide substrates, provided information on the strength of the substrate/additive interactions. Also, the visual representation of each additive molecule's alignment on the metallic surface has provided insight into selection of the optimnum functionality in designing new additives. Data on the additive/metal attraction and corresponding additive effectiveness are presented.     

Tribochemistry of Fluorinated Fluids Hydroxyl Groups on Steel and Aluminum Surfaces

This paper describes products of tribochemical reactions of Z-Dol 2500 and 1H,1H,2H,2H-tetra-fluorooctanol, produced on steel and aluminum surfaces. The fluorooctanol was used as a model compound to study the reactions of hydroxyl groups. Tribochemical reactions were initiated by friction in the steel/steel and steel/Al contacts, using an Optimol SRV (Schwingung Reibung Verschleiβ) reciprocating sliding tester. The products of these reactions, deposited in the wear scars on steel and Al discs, were studied using reflective FTIR spectrometry (microscopy and grazing angle) and X-Ray photoelectron spectroscopy (XPS). Under boundary lubrication conditions on metal surfaces, fluorinated compounds containing hydroxyl groups formed carboxylic and alkoxyl salts. FTIR spectra indicate that Fe and Al carboxylic salts occur mainly in bidentate configuration.     

Ultrafiltered Perfluoropolyether Lubricant under Molecular Weight Distribution Control

There are many problems to be overcome when storage devices are used at high-speed rotation and very small spacing between the head and disk. One of them is lubricant spin-off. Lubricant spin-off and lubricity have a close relation to the molecular weight distribution. The commercial Perfluoropolyether (PFPE), which is widely used as a lubricant for magnetic disks, has a wide molecular weight distribution from several hundred to over ten thousand. In order to improve performance regarding spin-off and lubricity, it is necessary to control the molecular weight distribution.

This paper discusses the relation between molecular weight of lubricants and spin-off, and stiction. The molecular weight at which spin off occurs easily is found to cause a high stiction. Furthermore, molecular weight distribution control by ultrafiltering is investigated.     

Lubricant Bonding Effects on Thin Film Disk Tribology

The magnetic recording industry predominantly uses Zdol to lubricate the carbon overcoat of magnetic recording disks. Zdol comprises a perfluoropolyether chain terminated with hydroxyl end groups that are capable of reversibly bonding to the carbon overcoat. Contact start/stop (CSS) tests were done to investigate the effects of Zdol lubricant bonding, thickness, and relative humidity on durability. The durability improved with increasing thickness of fully bonded or mobile Zdol. The durability decreased with increasing initial bonded fraction and with decreasing relative humidity. The bonded fraction increased with time during the tests at elevated temperature and low relative humidity.     

Lubricant-Enhanced Fatigue Crack Growth in Silicon Nitride

Effect of a fluorinated lubricant on the subcritical crack growth behavior of a Si₃N₄ ceramic was examined under cyclic loading condition. The fatigue lifetime of the specimens tested in the oil was shorter, particularly in the low stress regime, compared to that in air. The growth rate of the surface crack was measured in the oil and compared with that in humid air. Crack growth rate in the oil was twice that in the air. XPS analysis of the fatigue fracture surfaces revealed that F had reacted with yttria-containing grain boundary phase, while the fractographical examination indicated that the oil had caused the dissolution of the grain boundary phase. The dissolution was shown to reduce the extent of crack bridging behind the crack tip, resulting in a higher fatigue crack growth rate in the oil.     

Use of atmospheric pressure plasma to confer durable water repellent functionality and antimicrobial functionality on cotton/polyester blend

A non-thermal, high density atmospheric plasma glow discharge treatment was used to impart functionality to cotton/polyethylene terephthalate (PET) fabric to furnish a surface that is water repellent and then antimicrobial only.In this work, cotton/PET (50/50%) blend fabric was treated with a water repellent treatment through activating the surface with plasma, depositing a vaporized fluorocarbon based monomers, 1,1,2,2-tetrahydroperfluorodecyl acrylate (THPFDA) and 1,1,2,2-tetrahydroperfluorododecyl acrylate (THPFDDA), then graft polymerizing the monomer with a second plasma exposure. Samples were then further treated with an antimicrobial agent, diallyldimethylammonium chloride (DADMAC), a quaternary ammonium salt. Plasma treatment was used to induce free radical chain polymerization of the DADMAC, conferring a graft polymerized network on the fabric with potentially durable antimicrobial properties.It was shown that the water repellent treatment via plasma induced-graft polymerization was successful in yielding a highly hydrophobic fabric with a finish durable to laundering.The results of the antimicrobial tests showed that the treated fabric reduced the activity of both gram positive and gram negative bacteria by more than 99.994%, demonstrating that the antimicrobial agent can function effectively on the water repellent treated fabric. However, despite the evidence of the presence of fluorine containing compounds on the fabric following the antimicrobial treatment, which was confirmed by time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis, the water repellency was lost, which was attributed to changes in the orientation of the fluorocarbon polymer chains.