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Theory of Radiation-Induced Cracking Reactions in Hydrocarbons
Published in Yuriy Zaikin, Raissa Zaikina, Petroleum Radiation Processing, 2013
The observed data were explained in terms of a molecular decomposition accompanied by a radical chain reaction terminated in the gaseous phase. It was supposed that the radical chain reaction may be initiated both thermally and by radiation and involved the cracking of pentyl radicals. Competing with this cracking reaction, however, is a wall reaction of pentyl radicals with olefins, the magnitude of the wall effect being a function of the ratio of the lifetime of the radicals to their mean diffusion time to the walls. At degrees of conversion above about 60-70, secondary reactions based on unsaturated radicals, such as ally1, could replace the role of the pentyl radicals in the propagation of the reaction chain. These lead to the decrease in olefin concentration and to the production of aromatics found experimentally.
Metal Incorporation into Copper Aluminum Borates
Published in John R. Kosak, Thomas A. Johnson, Catalysis of Organic Reactions, 2020
Larry C. Satek, Patrick E. McMahon
Catalyst deactivation for this reaction is manifested as a decrease in conversion over time (Figure 5), consistent with a loss of dehydrogenation as an activating mechanism. The ratio of naphthalenes to tetralins, however, remains much higher (versus 5-OTP reaction) as deactivation occurs. Hydrocracking accounts for only about 10% of the product and remains essentially constant. The small product distribution change is comprised of the shift toward incomplete aromatization (methyltetralins versus methylnaphthalenes) and a small increase in the only olefin found, the ring conjugated product. Ring closure, through the internal carbon-4 of the pentyl chain, is favored over formation of the other two internal olefins.
INTRODUCTION AND OVERVIEW OF PART 2
Published in Nicholas P. Cheremisinoff, Industrial Solvents Handbook, Revised And Expanded, 2003
Chemical Designations — Synonyms: Amyl Acetate, Mixed Isomers; Pentyl Acetates; Chemical Formula: CHjCOOC;!! . Observable Characteristics — Physical State (as normally shipped): Liquid; Color: Colorless to yellow; Odor: Pleasant banana-like; mild; characteristic banana- or pear-like odor; Physical and Chemical Properties —- Physical State at 15°C and 1 atm.: Liquid; Molecular Weight: 130.19; Boiling Point at I atm.: 295, 146, 419; Freezing Point: -148, -100, 173; Critical Temperature: Not pertinent; Critical Pressure: Not pertinent; Specific Gravity: 0.876 at 20°C (liquid); Vapor (Gas) Density: Not pertinent; Ratio of Specific Heats of Vapor (Gas): Not pertinent; Latent Heat of Vaporization: 140, 75, 3.1; Heat of Combustion: -13,360, -7423, -310.8; Heat of
Quantitative analysis of molecular interactions between erythrosine B and cationic surfactants: liquid crystal-based sensor design for the efficient determination of erythrosine B
Published in Liquid Crystals, 2023
Fatemeh S. Mohseni-Shahri, Farid Moeinpour, Asma Verdian
By optical amplification of LCs, they can be transformed into a unique optical excavator to detect reactions, such as enzymatic reactions, ligand-receptor binding and peptide–lipid interactions at the LC/aqueous interface. These interactions manage the transition from homeotropic to planar arrangement within the LC molecule. The LC molecules are oriented parallel and opposite to the surface within the planar and isotopic arrangements, respectively [20]. Preceding work has shown that the reaction of LCs to an outside stimulus may be regulated by functionalising them with surfactants, due to surfactant self-assembly. Cationic surface at the LC–water interface, causing isotropic anchoring (through lateral hydrophobic interactions between the chain hydrocarbons of the cationic surfactant and the LC) [21]. Owing to the extensive utilisation of EB in different industries, it is worth studying EB–surfactant interaction. The first goal of this paper was to examine the interaction between EB and CTAB by spectrophotometry and in the next step, given the importance of measuring EB dye, a sensitive sensor was designed to detect this dye. TEM grid filled with nematic thermotropic LC, 5CB (4-cyano-4΄-pentyl biphenyl) was used by covering the cetyltrimethylammonium bromide (CTAB) as a cationic surfactant at the LC/water surface. Next, we analyse the selectivity and limit of detection (LOD) of this framework for EB detection, as a function of optical LC image change (Figure 1).
Synthesis and microwave dielectric properties of polyphenylene liquid crystal compounds with lateral substitution by methyl and fluorine
Published in Liquid Crystals, 2021
Haohao Liu, Manman Liu, Shihan Gao, Zhiyong Zhang, Xiangru Wang, Jintao Guan, Junfei Qiao, Hongmei Chen, Xionghui Cai
2-Fluoro-2’-methyl-4’’-pentyl-isothiocyanatoterphenyl (8a): 2-fluoro-2’-methyl-4”-pentyl-triphenylamine (5a) (4.4 g, 0.013 mol), calcium carbonate (3.17 g, 0.032 mol), water 5 mL, dichloromethane 100 mL were added to 250 mL triple flasks. The solution of carbon dichloride sulphide (CSCl2) (4.37 g,0.038 mol) and dichloromethane 10 mL was added dropwise into the flask and stirred for 1.5 h at 5°C, and then continued to stir for 1.0 h at r.t. Anhydrous ethanol 15 mL was added and stirred for 0.5 h at r.t. It was extracted with ethyl acetate (50 mL × 2), washed to neutral, and then dried by anhydrous sodium sulphate. The solvent was removed in vacuum, and the crude product was purified by silica gel column chromatography and recrystallisation. 4.24 g white solid of 8a was obtained. yield: 86.0%, m.p.: 70°C~71°C, FTIR (KBr, νmax, cm-1): 3442.36, 2924.46, 2856.55, 2049.23, 1648.53, 1476.32, 1185.79, 1121.17, 938.89, 880.22, 816.12; 1 H NMR (400 MHz, CDCl3, δ, ppm): 7.63–7.47 (m, 4H), 7.29 (ddd, J = 11.7, 9.0, 6.8 Hz, 4H), 7.23–7.10 (m, 2 H), 2.92–2.63 (m, 2 H), 2.37 (s, 3 H), 2.01–1.22 (m, 6 H), 0.96 (t, J = 6.7 Hz, 3 H); 13 C NMR (100 MHz, CDCl3, δ, ppm): 158.21,142.47, 141.06,140.25, 138.18, 137.81, 135.46, 129.96, 129.27, 128.93, 126.95, 126.03, 125.66, 125.62, 124.67, 117.35, 117.16, 35.64, 31.61, 31.23, 22.62, 20.60, 14.10; 19 F NMR (376 MHz, CDCl3, δ, ppm): −119.89; MS m/z (%): 390.1 (100%, M + 1); Anal. calcd for C25H24FNS: C 77.09, H 6.21, N 3.60, S 8.23; found C 76.43, H 6.18, N 3.68, S 7.81.
Conversion of levulinic acid and cellulose to γ-valerolactone over Raney-Ni catalyst using formic acid as a hydrogen donor
Published in Biofuels, 2021
Ananda S. Amarasekara, Yen Maroney Lawrence, Anthony D. Fernandez, Tony L. Grady, Bernard Wiredu
The development of efficient methods for the conversion of lignocellulosic biomass into platform-chemicals is one of the major thrust areas in the current biofuel research. The platform chemicals such as furfural, 5-hydroxymethylfurfural (HMF), levulinic acid (LA) and its hydrogenation product γ-valerolactone (GVL) envisaged in future bio-refinery schemes [1] and as sustainable alternatives to crude-oil based feedstocks [2]. Among these, the GVL or 5-methyldihydrofuran-2(3H)-one possesses potential applications as a green fuel additive, excellent solvent and fine chemical intermediate [3]. It can be directly used as a fuel as well as transformed to fuel precursors or monomers in renewable polymer industry [4,5]. Recently, GVL has been identified as a potential octane number boosting fuel additive to gasoline. Horváth et al. have concluded that GVL is a better alternative to ethanol as a fuel additive due to its lower vapor pressure and relatively higher energy content [6]. Furthermore, GVL does not form an azeotrope with water as compared with ethanol, which requires an energy-intensive concentration process to remove water during the ethanol production by fermentation [7]. In addition, GVL can be upgraded to valuable chemicals such as: 2-methyltetrahydrofuran [8], isooctane [9], 5-nonanone, 1,4-pentanediol, methyl-THF, methylpentenoate, butenes, α-methylene-γ-valerolactone, aromatic hydrocarbons [6,10–13], pentyl-valerate and pentane [14].