Soft EHL Lubrication of Complex Multiphase Fluids

Author(s):  
J. de Vicente ◽  
H. A. Spikes ◽  
J. R. Stokes

The lubrication properties of a series of multiphase water-based fluids of complex rheology and microstructure, including o/w emulsions, have been studied in a rolling-sliding steel ball-on-elastomer flat contact. The results show that friction curves of Newtonian fluids made over a wide range of entrainment speeds and viscosity can be used to identify the prevailing mechanisms of lubrication for more complex fluids and, for emulsions, to show the predominant film-forming phase.

2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 189-200 ◽  
Author(s):  
Primoz Ternik ◽  
Rebeka Rudolf

The present work deals with the natural convection in a square cavity filled with the water-based Au nanofluid. The cavity is heated on the vertical and cooled from the adjacent wall, while the other two horizontal walls are adiabatic. The governing differential equations have been solved by the standard finite volume method and the hydrodynamic and thermal fields were coupled together using the Boussinesq approximation. The main objective of this study is to investigate the influence of the nanoparticles? volume fraction on the heat transfer characteristics of Au nanofluids at the given base fluid?s (i.e. water) Rayleigh number. Accurate results are presented over a wide range of the base fluid Rayleigh number and the volume fraction of Au nanoparticles. It is shown that adding nanoparticles in a base fluid delays the onset of convection. Contrary to what is argued by many authors, we show by numerical simulations that the use of nanofluids can reduce the heat transfer rate instead of increasing it.


2013 ◽  
Vol 469 ◽  
pp. 3-6 ◽  
Author(s):  
Mu Li ◽  
Xiao Song Lin ◽  
Xiao Yu Li ◽  
Hai Qiao Wang

As the binder of waterborne inks, the capability of acrylic polymer has great influences on the quality of inks. In this contribution, structured latex particles with a poly (stryrene-butyl acrylate-methacrylate) core and a poly (butyl acrylate-methyl methacrylate-methacrylic acid-diacetone acrylamide (DAAM)) shell, which can be used as binders of water-based ink, were prepared by emulsion polymerization. The emulsion can cure in the course of film forming at ambient temperature through the reaction between DAAM and the adipic acid dihydrazide (ADH). Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), transmission electron microscopy (TEM), atomic force microscopy (AFM) were used to characterize the structures and study the properties of the latices. The drying time of the crosslinking latices was investigated. In addition, influences of DAAM monomer dosage and the mole ratio of DAAM to ADH on the mechanical properties of self-crosslinkable core-shell latices were also discussed. It was found that the core-shell crosslinkable particles with a low glass transition temperature (Tg) core and a high Tg shell have better film properties and would be more applicable to binders of water-based ink for plastic film, in comparison with those particles with a high Tg core and a low Tg shell.


2011 ◽  
Vol 239-242 ◽  
pp. 1359-1363
Author(s):  
Chao Hui Zhang ◽  
Si Si Liu ◽  
Yue Tao Sun ◽  
Jun Ming Liu

Aqueous solutions have found broad usages as lubricants, in conjunction with other possible utilizations, such as in metal working and other industries. Due to the inferior lubricity, functional additives are needed to improve their tribological performances among which aqueous surfactants are exclusively included. The film forming property of aqueous solution with polyethoxylated ether added (PEOE) is measured, taking consideration of the influences of the temperature and the concentration. The addition of PEOEs into aqueous solutions will largely increase the film forming capacity. But the concentration has only a minor influence on the lubrication property of the aqueous solutions with PEOEs. The cloud point will strongly alter the film forming characteristics.


2016 ◽  
Vol 68 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Weiwei Wang ◽  
Shan Jiang ◽  
Yan Shen ◽  
Shunba Xia ◽  
Jiujun Xu

Purpose – This paper aims to address the polymerization of 1-decene by [Emim]Cl/AlCl3 ionic liquid and the film-forming properties of the product compared with commercially available base stocks. Design/methodology/approach – Experiments were carried out to investigate the influence of [Emim]Cl/AlCl3 mole ratio, catalyst dosage, reaction temperature, reaction time and water on the polyreaction. Poly alpha-olefin (PAO) is prepared under optimal reaction condition. Film-forming properties of PAO have been compared with those of Group I, Group II and Group III base stocks, which are selected with approximately the same viscosity. Findings – Experimental results show that after a 4-h reaction time, yield of PAO can be higher than 85 per cent and viscosity index can be up to 160 with [Emim] Cl/AlCl3 mole ratio of 2:1, catalyst dosage of 3 per cent wt. and water content of 20 ppm. A strong influence of water on reaction is observed. With approximately the same viscosity, PAO shows the superiority in film thickness at low-sliding speeds compared with Group I and Group II base stocks. At high temperature, PAO provides a thicker film than other base stocks. Originality/value – In recent years, there has been considerable interest in ionic liquids. As a novel catalyst, it has so many advantages including low corrosion, low toxicity, low cost and a potentially wide range of properties compared with traditional catalysts. This paper reports the polymerization of 1-decene by [Emim]Cl/AlCl3 ionic liquid and the study on lubricating properties of PAO compared with mineral base stocks.


1990 ◽  
Vol 23 (6) ◽  
pp. 442-448
Author(s):  
V. L. Jack ◽  
V. A. Ashitkov ◽  
S. S. Mnatsakanov ◽  
E. E. Kalaus ◽  
L. G. Shaltyko

2007 ◽  
Vol 106 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Yifeng Liu ◽  
Wenchao Guan ◽  
Xuefeng Li ◽  
Mingxing Huang

2013 ◽  
Vol 469 ◽  
pp. 26-29 ◽  
Author(s):  
Dan Dan Wang ◽  
Xian Fu Wei ◽  
Bei Qing Huang

In order to enhance the adhension of ink, base ink was prepared with proper pigment and grinding resin, as well as dispersing agent, then compounded it and film-forming resin. The paper has studied the major factors, including grinding resin, film-forming resin and additives, which influenced the adhension of water-based ink on UV varnish. The results indicated that the content and the variety of grinding resin had a certain influence on the adhension of water-based ink. Besides, since the structure of film-forming resin is different, it has a significant effect on the adhension of water-based ink with the change of the variety of resin. Whats more, additives, which could decrease the surface tension of ink effectively and made the ink intend to adhere on UV varnish easily, is also an important factor that influences the adhension of the water-based ink on UV varnish.


Author(s):  
Wenchao Guan ◽  
Gang Ke ◽  
Changyu Tang ◽  
Yifeng Liu

This paper reports cellulose derivative—carboxymethyl cellulose (CMC) as a novel additive in a water-based stock (water content above 95 wt.%). Cellulose is one of the richest renewable resources on earth and has many peculiar qualities. Several cellulose derivatives such as CMC can easily dissolve in water and form stable thin film on the surface of metal. Several apparatus involving four-ball machine were used to investigate lubrication properties of the based stock containing CMC. The worn surfaces were observed with a scanning electron microscope. As the results, the anti-wear ability of the base stock is effectively increased by addition of a small amount (0.7 wt.%) of CMC. The additive with peculiar molecular structure contributes to abate the adhesion and scuffing of frictional pair effectively, hence improves the antiwear ability of the base stock. Thus CMC provides a potential application in the field of water-based stock lubrication.


2019 ◽  
Vol 20 (20) ◽  
pp. 5166
Author(s):  
Wei Song ◽  
Yadi Li ◽  
Xunhu Liu ◽  
Zongyi Xu ◽  
Jianhua Wu ◽  
...  

In order to improve the poor film-forming ability of polymeric ladderphane, di-block copolymers containing perylene diimide (PDI)-linked double-stranded poly(1,6–heptadiyne) ladderphane and branched alkyl side chains modified single-stranded poly(1,6–heptadiyne) were synthesized by metathesis cyclopolymerization (MCP) using Grubbs third-generation catalyst (Ru–III) in tetrahydrofuran solvent. The first block containing the ladderphane structure leads to higher thermal-stability, wider UV–vis absorption, lower LUMO level and ladderphane-induced rigidity and poor film-forming ability. The second block containing long alkyl chains is crucial for the guarantee of excellent film-forming ability. By comparing the effect of ladderphane structure on the resulted copolymers, single-stranded poly(1,6–heptadiyne) derivatives with PDI pedant were also processed. The structures of copolymers were proved by 1H NMR and gel permeation chromatography, electrochemical, photophysical, and thermal-stability performance were achieved by cyclic voltammetry (CV), UV-visible spectroscopy and thermogravimetric analysis (TGA) measurements. According to the experiment results, both copolymers possessed outstanding film-forming ability, which cannot be realized by small PDI molecules and oligomers. And they can serve as a superior candidate as for n-type materials, especially for their relatively wide range of light absorption (λ = 200~800 nm), and lower LUMO level (−4.3 and −4.0 eV).


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