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Lubricant Base Stock Production and Application
Published in Don M. Pirro, Martin Webster, Ekkehard Daschner, Lubrication Fundamentals, 2017
Don M. Pirro, Martin Webster, Ekkehard Daschner
The purpose of dewaxing is to remove normal paraffins from the waxy raffinate in order to improve its low-temperature performance properties. A mixture of solvents, methyl ethyl ketone (MEK) and toluene, cause the normal paraffins to form crystals at reduced temperatures. The wax crystals are then separated from the oil by filtration. (This is in contrast to phase separation used in the earlier solvent extraction process.) The function of the individual solvents is not entirely clear. Nevertheless, the combination of solvents does adjust the polarity of the solvent to optimize wax precipitation. Other solvent combinations such as MEK/methyl isobutyl ketone are also commonly used.
Sample Preparation Techniques
Published in Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus, Environmental Chemical Analysis, 2018
Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus
Chelation is by far the most common extraction technique for metals. An organic compound which has two or more groups which can attach to a metal ion is called a chelating agent. A complex formed between a metal and a chelating agent is called a chelate. These are generally hydrophobic in nature and soluble in organic solvents. Some common chelating agents used to extract metals from water samples are shown in Figure 6.14. Methyl isobutyl ketone (MIBK) is normally used as the extracting solvent.
Effects of Test Parameters on the Frictional Properties of Al/Diamond-Like Carbon Core-Shell Nanostructure-Textured Surfaces
Published in Tribology Transactions, 2022
Colin Phelan, Charles Miller, Josue A. Goss, Christopher Rincon, Ronghua Wei, Min Zou
The Al nanodot cores were deposited by electron beam lithography and a metal lift-off procedure, similar to those used in Fleming et al. (4). First, a positive tone electron resist (4% dilution of 495 k MW poly(methyl methacrylate) (PMMA)) was applied to a 100 crystalline Si wafer by a spin coater at a speed of 3000 rpm. Next, with a 50-kV accelerating voltage, 1 nA of current, and beam dose of 775–1000 μC/cm2, an electron beam writer exposed the electron resist. In a combination of methyl isobutyl ketone and isopropyl alcohol (IPA), the arrays were developed for 45 s. The mixture of methyl isobutyl ketone and IPA had a ratio of 1:3. Once developed, the arrays were rinsed with pure IPA for 15 s. Then, to smooth the edges of the PMMA film’s open holes, a 50-W low-pressure oxygen plasma etch was performed for 10 s. Afterward, 100 nm of Al was deposited on the patterned PMMA film via e-beam deposition. To eliminate excess PMMA, the sample was put in a bath of Remover PG heated to 75 °C for 48 h.
Optimization of operating conditions in purification of wet process phosphoric acid in a liquid-liquid extraction column
Published in Chemical Engineering Communications, 2022
Mohammad Daryani, Naeimeh Jodeiri, Esmaeil Fatehifar, Javad Shahbazi
Experimental results of previous researches indicate the desirability of this method for minimizing the impurities and improving the efficiency of acid or extraction (Mishra et al. 2011; Li et al. 2017b). In a study that has been carried out by solvent extraction method, the combination of cyclohexanol with kerosene has been applied (Li et al. 2017b), and the effect of the time, initial concentration of phosphoric acid, temperature, the concentration of cyclohexanol and organic to aqueous phase ratio was investigated. In this work, the behavior of impurity separation factor and acid extraction level based on parameter level change has been studied and the results showed that it takes almost 10 min to attain extract equilibrium. removal from ammonium dihydrogen phosphate solution by solvent extraction with 2-ethylhexyl phosphoric acid has been studied, and high removal rate for the impurity was achieved (Luo et al. 2011). The purification of WPPA by methyl isobutyl ketone solvent has been studied extensively (Feki et al. 2002). The tributylphosphate solvent has been highly regarded and suggested because of its selectivity and low solubility in water. Phosphate also improves the acid content (Hannachi et al. 2007).
Carbon nanotubes functionalized with newly synthesized benzimidazole derivative for corrosion inhibition on the nickel alloy surface in a sulfuric acidic medium
Published in Inorganic and Nano-Metal Chemistry, 2021
K. Jayamoorthy, P. Saravanan, Vaddi Seshagiri Rao, N. R. Rajagopalan, Sathish Rengarajan, P. Nisha
The use of polar solvents such as ketones is often used to assess the degree of cure of a cross-linked composition. For solvent resistance, methyl isobutyl ketone or acetone is recommended. In addition to immersion testing, solvent resistance may be assessed by a solvent rub rest. In this respect, acetone was used to determine the degree of curing of the present coating systems by rub method. Failure was determined either by distruption or dissolution of the coating films from panels. Higher the degree of cross-linking, better will be the film properties, ideally required for corrosion resistance. Hence solvent molecules can hardly penetrate the cross-linked network at all. In this respect, it was found that all the developed composite coatings successfully passed the acetone double rub test and there were no defects on the surface even after 27 double rubs of solvent, indicating their superior performance when compared with uncoated specimens.