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The foam tendency of aviation coolants (ACs) can be greatly influenced by additives. This study investigates the effect of additives on foam behaviors based on four commercial ACs and glycol aqueous solutions added with different additives. Experimental results show that the foam tendency of ACs can be greatly influenced by surfactants; however, inorganic salts have little effect on foam tendency. The volume of generated foam reaches up to 350 mL after ventilation for an AC with a surfactant, much larger than 40 mL of an AC with an inorganic salt. The surface tension of ACs reduces with the addition of surfactants, the lower the surface tension, the more the foam formation. Furthermore, the presence of arranged surfactants at the gas-solution interface can increase the intermolecular forces and enhance the liquid and viscosity of film elasticity, thereby enhancing the foam stability. Besides, the surfactants would weaken the gas diffusion of foams and affect the defoaming property of ACs accordingly.

The effect of cosolvent on trace free water in the determination of the contamination degree of jet fuel was investigated. The interference of trace free water on the automatic particle counter can be eliminated by adding isopropanol as a cosolvent to the measured oil sample. Isopropanol can dissolve trace free water in oil. Addition of isopropanol could stabilize the pollution grade of particles with size ≥30 μm (c) at the same level, which is most obviously affected by free water without isopropanol. The standard uncertainty u(X1) is slightly reduced with the addition of isopropanol, and the repeatability and accuracy of the automatic particle counting method are obviously improved. The results show that isopropanol should be added as a cosolvent to eliminate the interference of free water when the contamination degree of jet fuel oil samples with obvious free water is determined by the automatic particle counting method.

The poly(diphenylamine) derivative (PDPA) as amine antioxidant was synthesized via diphenylamine, styrene, and formaldehyde. The steps of the synthesis were discussed in detail, and the structure of PDPA was fully characterized with multiple analysis techniques. Furthermore, the anti-oxidative properties of PDPA were evaluated through oxidation–corrosion tests and differential scanning calorimetry. It was found that PDPA significantly improved the oxidation stability of base oils, especially pentaerythritol ester when it was added at concentrations of only 0.5 wt % to 0.8 wt %. Thermogravimetric analysis shows that anti-oxidation behavior of PDPA is better than traditional additive p, p-dioctylphenylamine. The synthesized PDPA antioxidant is a potential alternate additive in high-temperature conditions.

The styrenated sulfur- and phosphorus-free organic titanate (STAE) was synthesized via an in situ method with soybean oil, diethanolamine, and isopropyl titanate. The tribological and antioxidant behavior of the as-synthesized STAE as an additive in PAO was evaluated by a four-ball test, a rotary oxygen bomb test (ROBT), and differential scanning calorimetry (DSC), and its oxidative stability was estimated through thermogravimetric analysis (TGA). The as-synthesized STAE exhibits excellent antiwear and load-carrying capacities as well as good antiwear synergism with zinc dialkyldithiophosphate (ZDDP) in poly-α-olefin (PAO). STAE in PAO also showed good synergistic antioxidation effects with the traditional additive p,p-(dioctyldiphenylamine (DODPA). This is because STAE can effectively reduce the oxidation rate of DODPA, which was confirmed by the results of Fourier transform infrared spectroscopy (FTIR) and gas chromatography-tandem mass spectrometry (GC/MS).

The particulate contamination degree of aviation coolants (ACs) is overestimated commonly because the bubbles in ACs are erroneously recognized as particulate contaminants during the measurement process. In this work, the factors that influence the foam behavior and contamination degree of ACs are investigated. It is evidenced that the foam behavior of ACs is basically unaffected by the ratio of glycol to water of the base solution, which, however, is highly influenced by the organic additive. Also, the more the organic additive arranged at the gas-liquid interface, the lower the surface tension of glycol aqueous (GA) solution and the higher the contamination degree. Furthermore, the foam characteristics and contamination degree of ACs are highly affected by the working conditions, such as airflow, operating temperature, and gas pressure. Besides, the defoaming rate can be accelerated by adding an antifoaming agent or ultrasonic processing; however, the defoaming effect of the natural static method and pressuring positively treatment is disappointing. To further improve the defoaming effect, several efficient synergetic methods of defoaming have been proposed.

Water contamination in aviation jet fuel has been a particular concern throughout the aviation industry for many decades on account of any contaminating water may accelerate the corrosion of the aircraft fuel systems, diminish the lubricative properties of the fuel, promote microorganism growth, and more importantly, pose threat to flight safety. However, the water behavior of jet fuel has not been studied systematically so far, especially for the free water, which is the main factor that causes the hazards mentioned above. Herein, the water behaviors, including dissolved and free water behaviors versus storage time, temperature, relative humidity and anti-icing agent are investigated. Compared with storage time, temperature and relative humidity have a greater influence on the water solubility, and the respective exponential and linear relationships between the solubility of water and temperature and relative humidity are identified in this paper. Furthermore, a complete discussion is carried out on the effect of anti-icing agent on the solubility of water and free water content in jet fuel. More importantly, the real water behavior of jet fuel with anti-icing agent is also studied through simulating the variation in temperature during flight.

A new I2-mediated iodobenzannulation of yne-allenones has been established, enabling breaking/rearranging of C≡C bonds to selectively access 4-iodonaphthalen-1-ols with generally good yields. The resulting 4-iodonaphthalen-1-ols could serve as a new and reliable coupling reagent, which further reacted with H2O under the oxygen conditions to generate unexpected 1,2-carbonyls with good yields through Pd-catalyzed deiodinated carbonylation, whereas employment of benzene-1,2-diamine as the nucleophile rendered 3-(quinoxalin-2-yl)naphthalen-1-ols through Pd-catalyzed [4 + 2] heterocyclization. On the basis of the controlled experiments, the mechanism for forming 1,2-carbonyls was proposed, including an oxidative addition, 1,3-palladium migration, reductive elimination, and oxidative dehydrogenation sequence.

A novel method of catalytic thermometric titration has been developed for the determination of the acidity of oils using titration with KOH in isopropanol as titrant. The amounts of oil, concentration and delivery rate of titrant, volumes and types of thermometric end-point indicator were investigated. The results show that mixture of acetone and chloroform used as indicator exhibits strongly exothermic effects to reflect end point obviously. The results obtained from the thermometric titration have good agreement with standard potentiometric and visual titration methods. The procedure is fast, easy to use, accurate, and highly reproducible to measure lower acidity in coloured oils. It is very suitable for the routine process and quality control of many types of oils.

The different size of microplastic in the environments may affect the fate and effects of traditional hydrophilic chemicals. The effect of reaction time, pH, salinity and concentration on the adsorption of lubrication oil on the 20–140 μm sized polystyrene (micro-PS) and 50 nm polyethylene (nano-PE) were presented. The adsorption kinetics and isotherms of nano-PE and micro-PS can be satisfactorily fitted by pseudo-second-order kinetic model and Langmuir, respectively. The adsorption of lubrication oil on nano-PE and micro-PS significantly increased with increasing concentration of salinity, indicating that the outer-sphere surface complexation dominated lubricating oil sorption on nano-PE and micro-PS. The maximum adsorption capacity of lubricating oil on nano-PE and micro-PS was 6.8 and 5.2 g/g at pH 5.0 and 293 K, respectively. These results are of crucial importance to the application of microplastics as the promising adsorbent in natural environments.

Water content in jet fuels is detected by thermometric titration (TMT), and the optimal detected system is 2,2-dimethoxypropane as titrant, cyclohexane and isopropanol as titration solvents, and methanesulfonic acid as catalyst in this method. The amounts of oil, concentration and delivery rate of titrant, volumes, and the reliability and accuracy of thermometric titration were emphasized. The results show that the accuracy, validity, and reliability of TMT are excellent by different indicated spiked water contents. The obtained results between TMT and Karl Fischer titration have been proven to be in accord. But, the duration of titration merely spends 3–5 min in the whole process, greatly shortening the detected time. Therefore, rapid and accurate determination of trace water in a jet fuel can be realized by TMT.

A new hydrofunctionalization/bicyclization of C(sp3)-tethered 1,7-enynes toward benzo[a]fluoren-5-ones with good to excellent yields has been developed by using Iron(III)/PhSiH3 system as a hydride donor. This protocol involves a reductive 1,7-enyne-carboannulation cascade, leading to C(sp3) H and C C bond-forming events to rapidly build up tetracarbocyclic complexity. A wide range of functional groups relative to 1,7-enyne substrates were tolerated well under mild neutral-redox conditions.

A first atom-economic [2 + 2] cycloaddition/1,6-conjugate addition cascade of yne-allenones with C-nucleophiles including 1,3-dicarbonyls and α,α-dicyanoolefins under base-promoted conditions has been established, enabling the direct construction of C(sp3)–C(sp3) bonds to generate cyclobuta[a]naphthalen-1-ols with generally good yields. These resulting products have a cyclobutene unit that contains both an aryl and alkyl group.

Two oil-soluble organic titanium compounds (OTCs) such as titanium dialkyldithiocarbamate (TiDDC) and sulfurized titanate (TiS) were synthesized and identified by Fourier-transform infrared spectroscopy (FTIR). The antiwear and extreme pressure properties of TiDDC or TiS with borate ester containing nitrogen (BNO) additive in mineral base oils were evaluated by four ball tester. The results show that TiDDC and TiS not only possess good antiwear and load-carrying properties, respectively, but also exhibit good antiwear synergism with BNO additive without impairing extreme pressure performances. Moreover, the synergistic antiwear properties of the said additives are improved significantly under the optimum additives ratios. The topography of wear scar and the composition and chemical states of typical elements on the rubbing surfaces were analyzed by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) and X-ray photoelectron spectrometer (XPS). The proposed synergistic antiwear mechanism involves an effective interaction between TiDDC or TiS and BNO additive, respectively.

Ethylene glycol methyl fan is the main components of Anti icing additive of jet fuel. the volume percent of Anti icing additive in fuel is 0.1～0.15%. It is a typical detection problem of trace substances in complex organic phase to detecting the content of only 0.1 to 0.15% of the ether substances in jet fuel comprising of by hundreds of kinds of organic matter , so there is no on-line measurement method by now. In this paper , a means is offered that combine micro extraction technology and on-line optical spectroscopy technique . by this way, anti icing additive concentration can be real-time measured and the precision can reach 5%, can meet the need of oil blending control and quality detection.

The influence of the solvent temperature and the solvent quality on the chain conformation and the aggregation of semiconducting block copolymers is described in this paper. In selective solvents for the polystyrene block, aggregation is detected by means of optical spectroscopy. The author thinks that the research is useful for the development of material engineering.

The synthesis of platinum nanoparticles by reduction of H2PtCl6 with ascorbic acid has been studied. By high-resolution electron microscope and XRD analyses, the resultant nanoparticles have been found to be pure platinum of fcc structure. Their sizes were observed to increase with the increases chemical reductive with 24h. Then, platinum nanoparticles directly attached to Ti plates(Pt nanoparticles/Ti) were successfully fabricated. In this method, platinum nanoparticles could be grown on the Ti surface via the one-step immersion into the growth solution containing PtCl62- and ascorbic acid. The attached and grown platinum nanoparticles were spherical having an agglomerated nanostructure composed of small nanoclusters. The present Pt nanoparticles/Ti may be promising for a new type of electrode material.

A four-ball tester was used to evaluate the tribological performances of bismuth naphthenate (BiNap), sulfurized isobutene (VSB), and their combinations. The results show that the antiwear properties of BiNap and VSB are not very visible, but they possess good extreme pressure (EP) properties, particularly sulfur containing bismuth additives. Synergistic EP properties of BiNap with various sulfur-containing additives were investigated. The results indicate that BiNap exhibits good EP synergism with sulfur-containing additives. The surface analytical tools, such as X-ray photoelectron spectrometer (XPS) scanning electron microscope (SEM) and energy dispersive X-ray (EDX), were used to investigate the topography, composition contents, and depth profile of some typical elements on the rubbing surface. Smooth topography of wear scar further confirms that the additive showed good EP capacities, and XPS and EDX analyzes indicate that tribochemical mixed protective films composed of bismuth, bismuth oxides, sulfides, and sulfates are formed on the rubbing surface, which improves the tribological properties of lubricants. In particular, a large number of bismuth atoms and bismuth sulfides play an important role in improving the EP properties of oils.