Articles de revues : « Amine solvents »

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Liu, Xiangwei, Qian Ao, Shengyou Shi et Shuie Li. « CO₂ capture by alcohol ammonia based deep eutectic solvents with different water content ». Materials Research Express 9, n^o 1 (1 janvier 2022) : 015504. http://dx.doi.org/10.1088/2053-1591/ac47c6.

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Abstract The existing CO2 absorption by deep eutectic solvents is limited by the unavoidable water absorption problem during use. In this study, we prepared three deep eutectic solvents with different alcohol aminations and added different water contents to discuss the effect of water content on the absorption of carbon dioxide by deep eutectic solvents. All deep eutectic solvents have a low melting point at room temperature as a liquid and have high thermal stability, where the choline chloride-diethanolamine deep eutectic solvents have a high viscosity. Anhydrous choline chloride-monoethanolamine deep eutectic solvents have the largest CO2 absorption, reaching 0.2715 g g−1, and the absorption of CO2 by anhydrous choline chloride-N-methyldiethanolamine deep eutectic solvents is only 0.0611 g g−1. Water content inhibited the absorption of CO2 in primary amine and secondary amine systems, whereas it enhanced the absorption of CO2 in tertiary amine systems, which was related to the reaction process of deep eutectic solvent and CO2.

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Agarwal, Neha, Le Cao Nhien et Moonyong Lee. « Rate-Based Modeling and Assessment of an Amine-Based Acid Gas Removal Process through a Comprehensive Solvent Selection Procedure ». Energies 15, n^o 18 (18 septembre 2022) : 6817. http://dx.doi.org/10.3390/en15186817.

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In this study, an industrial acid gas removal (AGR) process which uses amine-based solvents was designed and simulated. The selection of suitable absorbents is crucial for an effective AGR process. Therefore, various single and blended amine-based solvents for capturing acid gases were evaluated through a comprehensive procedure, including solvent screening and process design steps. First, various solvents were screened for their CO2 and H2S absorption efficiencies. Promising solvents were then selected for the process design step, in which all process alternatives were simulated and rigorously designed using Aspen Plus. The non-equilibrium rate-based method with an electrolyte non-random two-liquid thermodynamic model was employed for modeling the absorption column. All processes were evaluated in terms of energy requirements, costs, and carbon emissions. The results show that a blend of methyldiethanolamine and piperazine solutions are the most promising solvents for the AGR process, as they can save up to 29.1% and 30.3% of the total annual costs and carbon emissions, respectively, compared to the methyldiethanolamine + diethanolamine solvent process.

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Vijayaraghavan, Ranganathan, et Douglas R. MacFarlane. « Charge Transfer Polymerization in Ionic Liquids ». Australian Journal of Chemistry 57, n^o 2 (2004) : 129. http://dx.doi.org/10.1071/ch03236.

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Charge transfer (CT) polymerization of methyl methacrylate has been successfully carried out by employing n-butyl amine and carbon tetrachloride as CT initiators and hydroquinone as promoter in room-temperature ionic liquids (ILs) as solvents. The reaction rate and polymer yields at short reaction times are enhanced in the IL solvent compared to conventional solvents. The effect of various reaction conditions including concentration of amine, IL, and temperature have been studied. The polymers were characterized for thermal and molecular weight properties and compared with the conventional CT reaction.

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Hasegawa, Miki, Yasunori Yamada, Ken-ichi Kumagai et Toshihiko Hoshi. « Electronic Structure of 2,6-Bis{.N-(2-hydroxyphenyl)immoinethyl}-4-methylphenol ». Zeitschrift für Naturforschung B 54, n^o 7 (1 juillet 1999) : 929–39. http://dx.doi.org/10.1515/znb-1999-0717.

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The electronic and molecular structure of 2,6-bis{N-(2-hydroxyphenyl)iminomethyl}-4- methylphenol (hpimp) is clarified from the measurements of electronic absorption and 1H NMR spectra in various solvents and an X-ray diffraction analysis, together with MO calculations. Electronic absorption bands of hpimp are at 422, 397.9, 359, 341, 294.3, 265.8, and 224 nm in the non-polar solvent cyclohexane. In polar solvents, such as methanol, an additional band which is assigned to a partly formed keto-amine hpimp, is observed at 499 nm. From the 1H NMR spectra it is seen that hpimp exists in the enol-imine form in non-polar solvents, and as an equilibrium mixture of enol-imine and keto-amine forms in polar solvents. Each electronic absorption band of solid hpimp in a KBr disk is broadened compared with the solution state, and an additional band, again assigned to the keto-amine form, appears around 499 nm. An X-ray diffraction analysis shows that hpimp assumes a keto-amine structure in the solid state, and forms a column structure along the c-axis. MO calculations suggest that the enol-imine hpimp has a twist structure around the two C−C single bonds, the twist angle being 100° to 120°.

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Saeed Alshahrani. « Amino silicones solvent advantages to capture CO2 and improve plant sustainability ». World Journal of Advanced Engineering Technology and Sciences 8, n^o 1 (28 février 2023) : 277–81. http://dx.doi.org/10.30574/wjaets.2023.8.1.0053.

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Results for novel amino silicone physical properties to capture carbon dioxide (CO2) were discussed in this article, that also investigated their potential economic benefits versus traditional amine solvents, such as monoethanolamine (MEA). A range of differing amino silicone solvents were tested for density, viscosity, vapor pressure, and heat value. The novel amino silicone solvents showed better results than conventional solvents for CO2 removal, demonstrating less density, lower vapor pressure, and reduced heat capacity. These advantages were also translated into economic benefits with respect to capital expenditure (CAPEX) and operation expenditure (OPEX).

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Luu, Xuan Dinh, Thanh Thuy Nguyen, Ba Thuan Le et Mai Huong Le Thi. « Separation of Th from leachate of monazite sulphation process using amine solvent extraction ». Nuclear Science and Technology 8, n^o 1 (1 septembre 2021) : 44–49. http://dx.doi.org/10.53747/jnst.v8i1.83.

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The solvent extraction is one of the most common method for separating Th from solution. Primary amine has higher selectivity for the extraction of Th(IV) than U(VI) and RE(III) in sulfate media. N1923 (a primary aliphatic amine with amino nitrogen linked to a secondary carbon consisting of branched alkyl groups in C19–23 range) is commonly used to extractTh. At room temperature using 0.1M N1923 amine as solvent in this work, the results showed thatthorium maximum extraction capacity was about 2.5g/L with concentration of sulfuric acid in the aqueous phase was 1M and for 3 minutes shaking. At room temperature for 3 minutes shaking the best conditions for scrubbing processwas using the mixture of acids H2SO4 0.2M and HNO3 0.1M, result inover 75%, Th was scrubbed in the aqueous phase only 0.7%. The separation of Th from leachate of monazite sulphation process was carried out on a multistage continuous flow extraction device (12 boxes), the thorium purity was 98%. Therefore, the use of amine solvents can purify thorium from rare-earth solutions in a sulfate medium

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Chen, Francis M. F., Young Lee, Rene Steinauer et N. Leo Benoiton. « Mixed anhydrides in peptide synthesis. A study of urethane formation with a contribution on minimization of racemization ». Canadian Journal of Chemistry 65, n^o 3 (1 mars 1987) : 613–18. http://dx.doi.org/10.1139/v87-105.

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A study of the factors contributing to urethane formation during the coupling of N-alkoxycarbonylamino acids with an amino acid ester by the mixed carboxylic–carbonic acid anhydride method has been carried out, using nuclear magnetic resonance spectroscopy and high-performance liquid chromatography for the quantitation of products. Urethane formation is associated primarily with reactions of activated hindered residues such as isoleucine and N-methylamino acids. Of prime importance in dictating the amount of urethane generated is the tertiary amine/solvent combination. N-Methylpiperidine/dichloromethane is the best combination for minimizing urethane formation, N-methylmorpholine/tetrahydrofuran is a good combination, while triethylamine/dichloromethane is a particularly bad one. In dimethylformamide, the differences between these amines are marginal. Aqueous dimethylformamide is a good solvent for mixed anhydride generation and coupling. A small excess of substrate reduces the amount of urethane. Less racemization accompanies the coupling of peptide acids in tetrahydrofuran than in halogen-containing solvents, N-methylpiperidine being the superior base in these solvents, but not in dimethylformamide. Racemization is reduced by one half when menthyl chloroformate instead of isobutyl chloroformate is used in the couplings.

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Raksajati, Anggit, Minh Ho et Dianne Wiley. « Solvent Development for Post-Combustion CO2 Capture : Recent Development and Opportunities ». MATEC Web of Conferences 156 (2018) : 03015. http://dx.doi.org/10.1051/matecconf/201815603015.

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Chemical absorption is widely regarded as the most promising technology for post-combustion CO2 capture from large industrial emission sources with CO2 separation from natural gas using aqueous amine solvent system having been applied since the 1930s. The use of monoethanolamine (MEA) in CO2 absorption system possesses several drawbacks, such as high regeneration energy, high solvent loss, and high corrosion tendency. Various solvents have been developed for post-combustion CO2 capture application including the development of aqueous solvents and phase-change solvents. Some of these alternate solvents have been reported to have better solvent properties, which could improve the CO2 absorption system performance. This paper reviews key parameters involved in the design improvement of several chemical absorption process systems. In addition, some novel solvent systems are also discussed, for example encapsulated solvents systems. Some of the key solvent parameters that affect the capture performance, such as heat of reaction, absorption rate, solvent working capacity, solvent concentration, and solvent stability, are discussed in this paper, particularly in relation to the economic viability of the capture process. In addition, some guidelines for the future solvent development are discussed.

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Li, Peng, et Huanrong Li. « Amine vapor responsive lanthanide complex entrapment : control of the ligand-to-metal and metal-to-metal energy transfer ». Journal of Materials Chemistry C 4, n^o 11 (2016) : 2165–69. http://dx.doi.org/10.1039/c5tc04377h.

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We develop a luminescent platform based on Eu³⁺ and Tb³⁺ co-doped nanozeolite to realize the probing of amine solvents. Such a luminescence sensor can classify amine solvents and achieve an excellent fingerprint correlation between the amine solvents (with larger pK_a values) and the emission intensity ratio (I_Eu/I_Tb), which is ratiometric.

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Wilson, Aaron D., et Frederick F. Stewart. « Structure–function study of tertiary amines as switchable polarity solvents ». RSC Adv. 4, n^o 22 (2014) : 11039–49. http://dx.doi.org/10.1039/c3ra47724j.

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A series of tertiary amines have been screened for their function as switchable polarity solvents (SPS). The relative ratios of tertiary amine and carbonate species as well as maximum possible concentration were determined. A new form of SPS with an amine : carbonate ratio significantly greater than unity has been identified. The N,N-dimethyl-n-alkylamine structure has been identified as important to the function of an SPS.

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Kalmykov, Denis, Alexey Balynin, Alexey Yushkin, Evgenia Grushevenko, Stepan Sokolov, Alexander Malakhov, Alexey Volkov et Stepan Bazhenov. « Membranes Based on PTMSP/PVTMS Blends for Membrane Contactor Applications ». Membranes 12, n^o 11 (17 novembre 2022) : 1160. http://dx.doi.org/10.3390/membranes12111160.

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In this work, perspective polymeric materials were developed for membrane contactor applications, e.g., for the dissolved oxygen removal from amine CO2 capture solvents. Several polymeric blends based on poly[1-trimethylsilyl-1-propyne] (PTMSP) and poly[vinyltrimethylsilane] (PVTMS) were studied. The gas and water vapor sorption and permeability coefficients for the PTMSP/PVTMS blend membranes at different PVTMS contents (0–100%) were obtained under temperatures of 30 and 60 °C for the first time. As the PVTMS content increases, the O2 and CO2 permeabilities decrease by 160 and 195 times at 30 °C, respectively. The fractional accessible volume of the polymer blends decreases accordingly. The transport of the CO2 capture solvent vapors through the PTMSP/PVTMS blend membranes were determined in thermo-pervaporation (TPV) mode using aqueous monoethanolamine (30%), N-methyldiethanolamine (40%), and 2-amino-2-methyl-1-propanol (30%) solutions as model amine solvents at 60 °C. The membranes demonstrated high pervaporation separation factors with respect to water, resulting in low amine losses. A joint analysis of the gas permeabilities and aqueous alkanolamine TPV data allowed us to conclude that the polymer blend composition of PTMSP/PVTMS 70/30 provides an optimal combination of a sufficiently high oxygen permeability and the pervaporation separation factor at a temperature of 60 °C.

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Shirokikh, Sergey, Denis Kalmykov, Dmitry Matveev et Stepan Bazhenov. « Reclaiming of Amine CO2 Solvent Using Extraction of Heat Stable Salts in Liquid-Liquid Membrane Contactor ». Membranes 13, n^o 2 (14 février 2023) : 230. http://dx.doi.org/10.3390/membranes13020230.

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Amine CO2 solvents undergo oxidative degradation with the formation of heat stable salts (HSS). These HSS reduce the sorption capacity of amines and lead to intense corrosion of the equipment. In our work, we propose a membrane-supported liquid-liquid extraction of the HSS from alkanolamines. For this purpose, a hollow fiber membrane contactor was used for the first time. A lab-scale extraction system on the basis of a hollow-fiber liquid-liquid membrane contactor with hollow fiber ultrafiltration polyvinylidenefluoride and polysulfone membranes has been studied. The extraction of the HSS-ions from a 30 wt.% solution of monoethanolamine was carried out using a 0.25–1 M solution of OH-modified methyltrioctylammonium chloride in 1-octanol as an extractant. It has been shown that >90% of HSS ions can be extracted from the alkanolamine solvent within 8 h after extraction. The results obtained confirm the possibility of using membrane extraction with a liquid-liquid membrane contactor for the reclaiming of amine CO2 solvents to increase the general efficiency of carbon dioxide capture.

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Eletta, O. A. A., D. T. Awotoye et A. A. Zubairu. « Investigation of Alkanol-Amine Solvents and their Blends for CO2 Removal from Natural Gas using Aspen-Hysys ». Nigerian Journal of Technological Development 18, n^o 4 (9 février 2022) : 268–78. http://dx.doi.org/10.4314/njtd.v18i4.2.

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The removal of carbon dioxide (CO2) from natural gas is vital towards meeting pipeline sales gas specifications and evading operational complications during the liquefaction of natural gas. Therefore, the removal of CO2 from natural gas is necessary for the efficient utilization of natural gas and for the reduction of global CO2 emission. It is also vital for the effective liquefaction process in the liquefied natural gas project A common and widespread technique used at natural gas plants in Nigeria is the removal of carbon dioxide (CO2) from natural gas through chemical absorption using alkanolamine solutions. In this research, an amine sweetening process is simulated using Aspen HYSYS V10 with a typical Nigerian natural gas composition. The simulation is used to investigate four different kinds of amines and their blends (mixed amines). The investigated amines are Monoethanolamine (MEA), Diethanolamine (DEA), Diglycolamine (DGA) and Methyldiethanolamine (MDEA) while the blends are MDEA + MEA, MDEA + DEA and MDEA + DGA. Results obtained from the simulation show that the mixed amine “MDEA + MEA” with lean amine strength of 11% MEA and 39% MDEA, absorbs 99.97% of CO2 present in the gas and hence, amine blends absorb carbon dioxide from natural gas better than the individual amines. It was also concluded that increasing the composition of the primary or secondary amine while decreasing the composition of the tertiary amine in the lean amine solution (amine blend) led to an increase in the amount of CO2 being absorbed. The study provides useful information on the absorption of CO2 using alkanolamine solvents and their blends in a standard amine sweetening plant.

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Jessop, Philip G., Lisa Kozycz, Zahra Ghoshouni Rahami, Dylan Schoenmakers, Alaina R. Boyd, Dominik Wechsler et Amy M. Holland. « Tertiary amine solvents having switchable hydrophilicity ». Green Chemistry 13, n^o 3 (2011) : 619. http://dx.doi.org/10.1039/c0gc00806k.

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Ramon, G., M. R. Caira et L. R. Nassimbeni. « Enclathration of amine solvents by resorcinarene ». Acta Crystallographica Section A Foundations of Crystallography 60, a1 (26 août 2004) : s216. http://dx.doi.org/10.1107/s0108767304095728.

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Pellegrini, Laura A., Matteo Gilardi, Fabio Giudici et Elvira Spatolisano. « New Solvents for CO2 and H2S Removal from Gaseous Streams ». Energies 14, n^o 20 (15 octobre 2021) : 6687. http://dx.doi.org/10.3390/en14206687.

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Acid gas removal from gaseous streams such as flue gas, natural gas and biogas is mainly performed by chemical absorption with amines, but the process is highly energy intensive and can generate emissions of harmful compounds to the atmosphere. Considering the emerging interest in carbon capture, mainly associated with increasing environmental concerns, there is much current effort to develop innovative solvents able to lower the energy and environmental impact of the acid gas removal processes. To be competitive, the new blends must show a CO2 uptake capacity comparable to the one of the traditional MEA benchmark solution. In this work, a review of the state of the art of attractive solvents alternative to the traditional MEA amine blend for acid gas removal is presented. These novel solvents are classified into three main classes: biphasic blends—involving the formation of two liquid phases, water-lean solvents and green solvents. For each solvent, the peculiar features, the level of technological development and the main expected pros and cons are discussed. At the end, a summary on the most promising perspectives and on the major limitations is provided.

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Villarroel, Josselyne A., Alex Palma-Cando, Alfredo Viloria et Marvin Ricaurte. « Kinetic and Thermodynamic Analysis of High-Pressure CO2 Capture Using Ethylenediamine : Experimental Study and Modeling ». Energies 14, n^o 20 (19 octobre 2021) : 6822. http://dx.doi.org/10.3390/en14206822.

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One of the alternatives to reduce CO2 emissions from industrial sources (mainly the oil and gas industry) is CO2 capture. Absorption with chemical solvents (alkanolamines in aqueous solutions) is the most widely used conventional technology for CO2 capture. Despite the competitive advantages of chemical solvents, the technological challenge in improving the absorption process is to apply alternative solvents, reducing energy demand and increasing the CO2 captured per unit of solvent mass. This work presents an experimental study related to the kinetic and thermodynamic analysis of high-pressure CO2 capture using ethylenediamine (EDA) as a chemical solvent. EDA has two amine groups that can increase the CO2 capture capacity per unit of solvent. A non-stirred experimental setup was installed and commissioned for CO2 capture testing. Tests of the solubility of CO2 in water were carried out to validate the experimental setup. CO2 capture testing was accomplished using EDA in aqueous solutions (0, 5, 10, and 20 wt.% in amine). Finally, a kinetic model involving two steps was proposed, including a rapid absorption step and a slow diffusion step. EDA accelerated the CO2 capture performance. Sudden temperature increases were observed during the initial minutes. The CO2 capture was triggered after the absorption of a minimal amount of CO2 (~10 mmol) into the liquid solutions, and could correspond to the “lean amine acid gas loading” in a typical sweetening process using alkanolamines. At equilibrium, there was a linear relationship between the CO2 loading and the EDA concentration. The CO2 capture behavior obtained adapts accurately (AAD < 1%) to the kinetic mechanism.

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Wilson, Aaron D., et Christopher J. Orme. « Concentration dependent speciation and mass transport properties of switchable polarity solvents ». RSC Advances 5, n^o 10 (2015) : 7740–51. http://dx.doi.org/10.1039/c4ra08558b.

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Tertiary amine switchable polarity solvents (SPS) were produced at various concentrations for three different amines and physical properties measured. The data allowed the identification of various molecular solution states and material trends.

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Faizi, Md Serajul Haque, Saima Kamaal, Arif Ali, Musheer Ahmad et Irina A. Golenya. « Crystal structure of 4-(2-hydroxy-3-methoxybenzylamino)benzoic acid dimethylformamide monosolvate monohydrate ». Acta Crystallographica Section E Crystallographic Communications 75, n^o 5 (18 avril 2019) : 646–49. http://dx.doi.org/10.1107/s2056989019005103.

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The title compound, C15H15NO4·C3H7NO·H2O, a secondary amine molecule, is accompanied by one equivalent of water and one equivalent of dimethylformamide (DMF) as solvents. The molecule is non-planar, with a Caryl—CH2—NH—Caryl torsion angle of −66.3 (3)°. In the crystal, O—H...O and N—H...O hydrogen-bonding interactions between the amine molecules and the two types of solvent molecule result in the formation of a layered structure extending parallel to (010).

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Ony`sko, Petro P., Tetyana I. Chudakova, Vladimir V. Pirozhenko et Alexandr B. Rozhenko. « α-Ketophosphonates in the Synthesis of α-iminophosphonates ». Current Green Chemistry 7, n^o 2 (21 septembre 2020) : 226–38. http://dx.doi.org/10.2174/2213346107666200226095806.

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The potentialities of condensation of α-ketophosphonates with primary amines for direct synthesis of α-iminophosphonates have been revealed. Diesters of α-ketophosphonic acids react with the primary amines by two competitive pathways: with a formation of α-iminophosphonates or a C-P bond cleavage resulting in a hydrogen phosphonate and an acylated amine. In many cases, the latter undesirable pathway is dominant, especially for more nucleophilic alkyl amines. Using metallic salts of α-ketophosphonates avoids the C-P bond cleavage, allowing direct preparation of α-phosphorylated imines by the reaction with primary amines. This strategy provides an atom economy single-stage synthesis of iminophosphonates – precursors of bio relevant phosphorus analogs of α-amino acids. Methyl sodium iminophosphonates, bearing aryl or heteryl substituents at the imino carbon atom exist in solutions at room temperature as an equilibrium mixture of Z- and E-isomers. A configuration of the C=N bond can be controlled by the solvent: changing the aprotic dipolar solvent DMSO-d6 by water or alcohols leads to the change from a predominant Z-isomer to almost an exclusive E-form. In contrast, diesters of the respective iminophosphonates exist in non-protic solvents predominantly in Econfiguration. The solvent effect on E-Z stereochemistry is demonstrated by DFT calculations.

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Wang, Siqi, Wanli Chen et Jun Ling. « PiPo : random copolymers of C- with N-substituted glycines ». Polymer Chemistry 13, n^o 3 (2022) : 383–87. http://dx.doi.org/10.1039/d1py01456k.

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This letter introduces a method to obtain PiPo by the copolymerization of N-phenyloxycarbonyl-amino acids initiated by primary amine. The obtained PiPo have adjustable solubility in water and organic solvents to assemble into nanoparticles.

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Ali, Syed Awais, Waqad Ul Mulk, Zahoor Ullah, Haris Khan, Afrah Zahid, Mansoor Ul Hassan Shah et Syed Nasir Shah. « Recent Advances in the Synthesis, Application and Economic Feasibility of Ionic Liquids and Deep Eutectic Solvents for CO2 Capture : A Review ». Energies 15, n^o 23 (30 novembre 2022) : 9098. http://dx.doi.org/10.3390/en15239098.

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Global warming is one of the major problems in the developing world, and one of the major causes of global warming is the generation of carbon dioxide (CO2) because of the burning of fossil fuels. Burning fossil fuels to meet the energy demand of households and industries is unavoidable. The current commercial and experimental techniques used for capturing and storing CO2 have serious operational and environmental constraints. The amine-based absorption technique for CO2 capture has a low absorption and desorption ratio, and the volatile and corrosive nature of the solvent further complicates the situation. To overcome all of these problems, researchers have used ionic liquids (ILs) and deep eutectic solvents (DESs) as a replacement for commercial amine-based solvents. ILs and deep eutectic solvents are tunable solvents that have a very low vapor pressure, thus making them an ideal medium for CO2 capture. Moreover, most ionic liquids and deep eutectic solvents have low toxicity and can be recycled without a significant loss in their CO2 capture capability. This paper first gives a brief overview of the ILs and DESs used for CO2 capture, followed by the functionalization of ILs to enhance CO2 capture. Moreover, it provides details on the conversion of CO2 into different valuable products using ILs and DESs, along with an economic perspective on using both of these solvents for CO2 capture. Furthermore, it provides insight into the difficulties and drawbacks that are faced by industries when using ILs and DESs.

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Gómez-Díaz, Diego, José Manuel Navaza et Antonio Rumbo. « Carbon Dioxide Chemical Absorption Using Diamines with Different Types of Active Centers ». Separations 9, n^o 11 (3 novembre 2022) : 343. http://dx.doi.org/10.3390/separations9110343.

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The present research analyzes chemical solvents based on the use of diamines (Ethylenediamine-EDA, 1,2-Dimethylethylenediamine-DMEDA and Tetramethylethylenediamine-TMEDA) for carbon dioxide absorption, taking into account the type of amino centers in the molecules. The presence and type of radicals can affect amine solubility in water, reaction mechanism, reaction kinetics, etc. Diamines have been considered interesting candidates for carbon dioxide chemical absorption, observing a high influence of the molecule structure. The present work analyzes a series of solvents based on diamines with the same chain length between amino centers, but different types of radicals. This study shows an important variability in the behavior of these solvents. EDA-based solvents have shown high absorption rates and stability, but carbamate hydrolysis is relatively low, avoiding an increase in carbon dioxide loading.

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Tzitzios, V., V. Georgakilas, I. Zafiropoulou, N. Boukos, G. Basina, D. Niarchos et D. Petridis. « A General Chemical Route for the Synthesis of Capped Nanocrystalline Materials ». Journal of Nanoscience and Nanotechnology 8, n^o 6 (1 juin 2008) : 3117–22. http://dx.doi.org/10.1166/jnn.2008.078.

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Noble metals, magnetic and semiconducting nanocrystalline materials have been synthesized via the thermolytic decomposition of inorganic metal salts, at high temperature, in commercial oleyl amine. The oleyl amine acts as high boiling point coordinating solvent, capping agent and, when required, as reducing agent. The crystal structure and morphology of the nanostructured materials have been studied with powder X-ray analysis (XRD) and transmission electron microscopy (TEM). The particles are well dispersed in non polar solvents such as hexane, toluene and chloroform and have uniform morphology.

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Shoukat, Usman, Diego Pinto et Hanna Knuutila. « Study of Various Aqueous and Non-Aqueous Amine Blends for Hydrogen Sulfide Removal from Natural Gas ». Processes 7, n^o 3 (15 mars 2019) : 160. http://dx.doi.org/10.3390/pr7030160.

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Various novel amine solutions both in aqueous and non-aqueous [monoethylene glycol (MEG)/triethylene glycol(TEG)] forms have been studied for hydrogen sulfide (H2S) absorption. The study was conducted in a custom build experimental setup at temperatures relevant to subsea operation conditions and atmospheric pressure. Liquid phase absorbed H2S, and amine concentrations were measured analytically to calculate H2S loading (mole of H2S/mole of amine). Maximum achieved H2S loadings as the function of pKa, gas partial pressure, temperature and amine concentration are presented. Effects of solvent type on absorbed H2S have also been discussed. Several new solvents showed higher H2S loading as compared to aqueous N-Methyldiethanolamine (MDEA) solution which is the current industrial benchmark compound for selective H2S removal in natural gas sweetening process.

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Sembiring, Maria Peratenta, Desi Heltina, Chairul Chairul et Zulfansyah Zulfansyah. « EKSTRAKSI UNSUR FERRUM DARI LIMBAH PADAT PABRIK PULP DAN KERTAS ». JURNAL KIMIA SAINTEK DAN PENDIDIKAN 6, n^o 1 (24 juillet 2022) : 21–25. http://dx.doi.org/10.51544/kimia.v6i1.3012.

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Functioning industrial waste as raw material or as a product is an achievement that will continue to be optimized, especially in industries where the amount of waste is significant. Pulp and paper mills produce waste in the form of solid, sludge, liquid and gas. The objective of this research is to extract the element ferrum contained in one of the solid wastes in pulp and paper mills. By using two fatty amine extractor, lauryl amine and stearyl amine with ethanol and n-hexane as solvents. The results showed that the use of stearyl amine as an extractor and n-hexane as a solvent with operating conditions of 4 hours and a dose of 5 grams gave the best results with an extraction yield of 10,964 mg/kg.

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Kobrak, Mark N., Dmytro Nykypanchuk et Camiel H. C. Janssen. « Relationship between liquid nanoscale structure in solvents and the strength of the Hofmeister effect in extraction experiments ». Physical Chemistry Chemical Physics 23, n^o 10 (2021) : 6266–77. http://dx.doi.org/10.1039/d0cp05973k.

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In this study, we used mixtures of carboxylic acids and amines as solvents for the liquid–liquid extraction of copper salts with various anions from aqueous phase, and systematically varied the acid/amine ratio to determine its influence on extraction efficiency.

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Adamoczky, Anita, Lajos Nagy, Miklós Nagy, Miklós Zsuga et Sándor Kéki. « Conversion of Isocyanide to Amine in The Presence of Water and Hg(II) Ions : Kinetics and Mechanism as Detected by Fluorescence Spectroscopy and Mass Spectrometry ». International Journal of Molecular Sciences 21, n^o 15 (4 août 2020) : 5588. http://dx.doi.org/10.3390/ijms21155588.

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Aromatic isocyanides including isocyanonaphthalene derivatives have been proven to be very effective fluorescent sensors for the quantification of Hg(II) ions in water. Thus, the reaction of 1,5-isocyanoaminonaphthalene (1,5-ICAN), which is one of the most important members of this family, with water and HgCl2 as the oxidation agents, was studied by fluorescence spectroscopy and mass spectrometry in order to get deeper insight into the kinetics and mechanistic details of this complex reaction. The reactions of 1,5-ICAN with water and HgCl2 were performed in various water/co-solvent mixtures of different compositions. The co-solvents used in this study were both aprotic solvents including tetrahydrofuran, acetonitrile and N,N-dimethylformamide and protic solvents, such as ethanol and 2-propanol. It was found that in aprotic solvents the conversion of the isocyano group to amino moiety takes place, while in protic solvents the corresponding carbamate (urethane) group is formed in addition to the amino moiety. The variation of the resulting fluorescence intensities versus time curves were described using an irreversible, consecutive reaction model, in which the formation of isocyanate and carbamic acid intermediates, as well as diamino and carbamate (in the case of protic solvents) products were assumed. The formation of these intermediates and products was unambiguously confirmed by mass spectrometric measurements. Furthermore, by fitting the model to the experimental fluorescence versus time curves, the corresponding rate coefficients were determined. It was observed that the overall rate of transformation of the isocyano group to amino moiety increased with the water concentration and the polarity of the co-solvent. It was also supported that formation of diamino and carbamate derivatives in protic solvents takes place simultaneously and that the ratio of the amino to the carbamate function increased with the increasing water concentration. In addition, with an extension, the model presented herein proved to be capable of describing the kinetics of the transformation of 1,5-diisocyanonaphthalene (1,5-DIN) into 1,5-diaminonaphthalene (1,5-DAN) in the mixtures of water/aprotic solvents.

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Zhao, Yixing, et Gordon R. Freeman. « Optical absorption spectra of solvated electrons in 1-butylamine–water mixed solvents ». Canadian Journal of Chemistry 73, n^o 12 (1 décembre 1995) : 2126–30. http://dx.doi.org/10.1139/v95-262.

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The optical absorption spectra of es− in 1-butylamine–water mixed solvents increase smoothly in energy and intensity as the water content is increased, with the exception of a small decrease in intensity on going from 95 to 100 mol% water. At 298 K the value of Gεmax increases from 1.42 × 10−21 m2/16 aJ (8.6 × 103 es−L/100 eV mol cm) in pure 1-butylamine to 8.3 × 10−21 m2/16 aJ (50 × 103 es−L/100 eV mol cm) in pure water, and the value of EAmax increases from 115 zJ (0.72 eV) to 278 zJ (1.74 eV). In the pure amine, if G(es−) = 0.27, then εmax = 5.3 × 10−21 m2/es− (3200 m2/mol). The solvent composition dependences of Gεmax and EAmax indicate little selective solvation of es− by water; this might be due to relatively "ideal" mixing of water and amine in the binary solvents. The temperature coefficient −dEAmax/dT = 0.43 zJ/K in pure 1-butylamine, 0.47 in pure water, and has a minimum of 0.27 in the 50:50 mixture. Keywords: 1-butylamine–water mixed solvents, optical absorption spectra, solvated electron, temperature dependence.

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Senchikhin, I. N., E. S. Zhavoronok, E. V. Kharitonova et V. I. Roldugin. « MODIFICATION OF EPOXY-AMINE POLYMERS BY OLIGOHEXAMETHYLENEGUANIDINES ». Fine Chemical Technologies 11, n^o 6 (28 décembre 2016) : 98–102. http://dx.doi.org/10.32362/2410-6593-2016-11-6-98-102.

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Methods of introducing a water-soluble biocide modifier, oligohexamethyleneguanidine hydrochloride, into epoxy-amine systems were studied. The obvious way is the introduction of the modifier in the waterborne epoxy-amine systems. However, this leads to cured systems with reduced mechanical properties. Introduction of oligohexamethyleneguanidine hydrochloride solutions in organic solvents into epoxy-amine systems allows obtaining a homogeneous system, but their application is limited by the presence of a volatile solvent. Finally, introduction of oligohexamethyleneguanidine hydrochloride solutions in a water-soluble amine curing agent into epoxy-amine systems has good prospects. It is shown that the analyzed modifier has good solubility in ethylenediamine, but poor solubility in oligooxypropylenediamine. It was found that the modifier is capable of interacting chemically with epoxy resins at 22°C to form an elastic insoluble material. In an epoxy-amine system with a more active hardener (ethylenediamine) oligohexamethyleneguanidine hydrochloride acts as a plastifier (flexibilizer). This significantly reduces the glass transition temperature of the matrix (from 53 to 37ºC).

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Kim, Sunkyung, Hu Shi et Jin Yong Lee. « CO 2 absorption mechanism in amine solvents and enhancement of CO 2 capture capability in blended amine solvent ». International Journal of Greenhouse Gas Control 45 (février 2016) : 181–88. http://dx.doi.org/10.1016/j.ijggc.2015.12.024.

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Pishro, Khatereh Ali, Ghulam Murshid, Farouq Sabri Mjalli et Jamil Naser. « Measurement of CO2 Solubility in Amine Based Deep Eutectic Solvents ». International Journal of Environmental Science and Development 11, n^o 9 (2020) : 438–41. http://dx.doi.org/10.18178/ijesd.2020.11.9.1287.

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The climate change assumes the warming of the climate systems due to increase of global average temperature to the observed increase of the greenhouse gas (GHG) concentration in the atmosphere. Carbon dioxide (CO2) is considered the most important GHG. The processes of CO2 capture are gaining a great attention on the scientific community as an alternative for decreasing CO2 emission and reducing its concentration in ambient air. In this study, we report a new deep eutectic solvents (DESs) made of monoethanolamine hydrochloride-diethylenetriamine exhibits a great candidate for CO2 capture. We developed solubility and physical properties studies at different pressures and temperatures, and regression model was well in agreement with the calculated αCO2 values with R-square: 0.976. The strong properties of DESs in CO2 capture make them as a suitable solvent for absorption CO2 to replace the conventional amine based scrubbing technology and are worth for further exploration.

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Torregrosa-Chinillach, Alejandro, Alba Sánchez-Laó, Elisa Santagostino et Rafael Chinchilla. « Organocatalytic Asymmetric Conjugate Addition of Aldehydes to Maleimides and Nitroalkenes in Deep Eutectic Solvents ». Molecules 24, n^o 22 (9 novembre 2019) : 4058. http://dx.doi.org/10.3390/molecules24224058.

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A chiral primary amine-salicylamide is used as an organocatalyst for the enantioselective conjugate addition of α,α-disubstituted aldehydes to maleimides and nitroalkenes. The reactions are performed in deep eutectic solvents as reaction media at room temperature, leading to the corresponding adducts with enantioselectivities up to 88% (for maleimides) and 80% (for nitroalkenes). Catalyst and solvent can be recovered and reused.

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Berman, Edward D., Rosemarie Thomas, Philip Stahl et Ronald M. Scott. « Specific patterns of short range solvation — aliphatic amines in benzene–dimethylsulfoxide mixed solvents ». Canadian Journal of Chemistry 65, n^o 7 (1 juillet 1987) : 1594–98. http://dx.doi.org/10.1139/v87-267.

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The trends in the values of equilibrium constants for the formation of proton transfer complexes between 2,4-dinitrophenol and various aliphatic amines are used to infer the nature of the short range solvation of the amines in benzene–DMSO solvent mixtures. Hydrogen bonds between the DMSO oxygen and the amine proton increase the basicity of the primary and secondary amines. Equilibrium constants for this bond formation are estimated for secondary amines.

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Yuan, X., E. G. Kim, C. A. Sanders, B. E. Richter, M. F. Cunningham, P. G. Jessop et R. D. Oleschuk. « CO2-modified solvents for chromatographic separation ». Green Chemistry 19, n^o 7 (2017) : 1757–65. http://dx.doi.org/10.1039/c6gc03405e.

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Yong, Ruth, Abdulhalim Shah Maulud et Humbul Suleman. « Economic Optimization of CO₂ Capture Process Using MEA-MDEA Mixtures ». Applied Mechanics and Materials 625 (septembre 2014) : 422–25. http://dx.doi.org/10.4028/www.scientific.net/amm.625.422.

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Amine based solvents are extensively being used for post combustion carbon capture through absorption. Each solvent has its associated benefits and drawbacks. In order to overcome their drawbacks, a number of mixed amine streams have been used. However, this amalgamation step is usually overshadowed by process optimization issues and cost limitations. In this study, Monoethanolamine (MEA) – Methyldiethanolamine (MDEA) is used as the mixed amine-based solvent for removal of carbon dioxide. A simulation model of CO2removal is developed using Aspen HYSIS to optimize the process. Subsequently, an economic analysis is constructed to evaluate the operating expenditure (OPEX) and capital expenditure (CAPEX) based on the simulation model, followed by sensitivity analysis. It is found that 25 wt% MDEA and 15 wt% MEA is the optimal operating condition that achieve the minimal total cost. Sensitivity analysis reveals that utilities cost affects the total cost significantly, followed by CAPEX. However, the effect of raw material costs on total cost is negligible.

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Danilkina, Natalia A., Ekaterina V. Andrievskaya, Anna V. Vasileva, Anna G. Lyapunova, Andrey M. Rumyantsev, Andrey A. Kuzmin, Elena A. Bessonova et Irina A. Balova. « 4-Azidocinnoline—Cinnoline-4-amine Pair as a New Fluorogenic and Fluorochromic Environment-Sensitive Probe ». Molecules 26, n^o 24 (9 décembre 2021) : 7460. http://dx.doi.org/10.3390/molecules26247460.

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A new type of fluorogenic and fluorochromic probe based on the reduction of weakly fluorescent 4-azido-6-(4-cyanophenyl)cinnoline to the corresponding fluorescent cinnoline-4-amine was developed. We found that the fluorescence of 6-(4-cyanophenyl)cinnoline-4-amine is strongly affected by the nature of the solvent. The fluorogenic effect for the amine was detected in polar solvents with the strongest fluorescence increase in water. The environment-sensitive fluorogenic properties of cinnoline-4-amine in water were explained as a combination of two types of fluorescence mechanisms: aggregation-induced emission (AIE) and excited state intermolecular proton transfer (ESPT). The suitability of an azide–amine pair as a fluorogenic probe was tested using a HepG2 hepatic cancer cell line with detection by fluorescent microscopy, flow cytometry, and HPLC analysis of cells lysates. The results obtained confirm the possibility of the transformation of the azide to amine in cells and the potential applicability of the discovered fluorogenic and fluorochromic probe for different analytical and biological applications in aqueous medium.

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Confer, Matthew P., Alice DeSimone, Hope Burnham, William McLeod, Tonya M. Klein, Shane C. Street et David A. Dixon. « Solubility thermodynamics of amine boranes in polar solvents ». International Journal of Hydrogen Energy 46, n^o 18 (mars 2021) : 10801–8. http://dx.doi.org/10.1016/j.ijhydene.2020.12.163.

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Woo, Jonathan C. G., Xueqing Wang et Richard B. Silverman. « Monoamine oxidase-catalyzed amine oxidation in organic solvents ». Journal of Organic Chemistry 60, n^o 19 (septembre 1995) : 6235–36. http://dx.doi.org/10.1021/jo00124a054.

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Barzagli, Francesco, Sarah Lai, Fabrizio Mani et Piero Stoppioni. « Novel Non-aqueous Amine Solvents for Biogas Upgrading ». Energy & ; Fuels 28, n^o 8 (29 juillet 2014) : 5252–58. http://dx.doi.org/10.1021/ef501170d.

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Guiton, Theresa A., et Carlo G. Pantano. « Solution/gelation of arsenic trisulfide in amine solvents ». Chemistry of Materials 1, n^o 5 (septembre 1989) : 558–63. http://dx.doi.org/10.1021/cm00005a018.

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Liu, Hanbi, Omkar A. Namjoshi et Gary T. Rochelle. « Oxidative Degradation of Amine Solvents for CO2 Capture ». Energy Procedia 63 (2014) : 1546–57. http://dx.doi.org/10.1016/j.egypro.2014.11.164.

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Spietz, Tomasz, Marcin Stec, Andrzej Wilk, Aleksander Krótki, Adam Tatarczuk et Lucyna Więcław‐Solny. « Density correlation of carbonated amine solvents forCO2loading determination ». Asia-Pacific Journal of Chemical Engineering 13, n^o 6 (26 septembre 2018) : e2248. http://dx.doi.org/10.1002/apj.2248.

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Tamajón, F. J., Estrella Álvarez, F. Cerdeira et M. E. Vázquez. « Comparative Study of CO₂ Absorption in Aqueous Mixtures of Methyldiethanolamine (MDEA) and Methanol, Focusing on the Temperature and Concentration Influence over the Absorption Rate ». Defect and Diffusion Forum 353 (mai 2014) : 193–98. http://dx.doi.org/10.4028/www.scientific.net/ddf.353.193.

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The use of tertiary methyldiethanolamine (MDEA) as an absorbent for the CO2 removal from process gas streams has increased due to its advantages over primary and secondary amines. Methanol is also widely used as an organic physical solvent for the CO2 capture. Mixed solvents are expected to have a higher capacity for the acid gases than the solvent alone. The chemical absorption rate of CO2 was measured in mixtures of MDEA (weight 5%, 15% and 30%) and water-methanol solutions at different % weight relations by using a stirred-cell reactor with plane gas-liquid interface. Experiments provided data measured at a range from 283.15 K to 313.15 K operation temperatures. Results show how the solubility of CO2 varies in all systems involved focusing on temperature and concentration changes. The solubility of CO2 in the aqueous mixed MDEA with methanol as a solvent becomes significantly greater than in the aqueous amine alone.

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Chen, Lu Yi, Jian Gang Chen, Xin Hui Ruan, Su Xin Xu, Yi Qi Yang et Bi Jia Wang. « Sustainable Reactive Dyeing of Cotton Fabric in Green Non-Aqueous Medium : A Density Function Theory (DFT) Modeling Study ». Key Engineering Materials 671 (novembre 2015) : 139–48. http://dx.doi.org/10.4028/www.scientific.net/kem.671.139.

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Sustainable reactive dyeing of cotton in green non-nucleophilic solvents was investigated. Dye fixation in the new medium was modeled using DFT calculations with the aim of understanding the role of organic bases. The novel procedure uses non-nucleophilic green solvents instead of water to eliminate the dye hydrolysis. All residuals in the spent dye bath could be conveniently recycled and reused. The three major stages in cotton reactive dyeing, cellulose swelling, dye adsorption and dye fixation were optimized respectively. Two organic bases and potassium carbonate were studied for dye fixation. The mechanisms of the amine-promoted dye fixation were modeled using density function theory (DFT) calculations. The formation of the amine-dye intermediate was elucidated and analyzed using high performance liquid chromatography (HPLC) analysis. The quaternary ammonium catalysis effect on intermediates forming was observed. A 10-cycle repeated dyeing sequence was demonstrated using Reactive orange 5 to give consistently high shade buildup, excellent colorfastness and dramatic reduction in resource consumption. The results have implications for better understanding the new hydrolysis-free and recyclable solvent dyeing process.

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Liu, Yanrong, Zhengxing Dai, Fei Dai et Xiaoyan Ji. « Ionic Liquids/Deep Eutectic Solvents-Based Hybrid Solvents for CO2 Capture ». Crystals 10, n^o 11 (29 octobre 2020) : 978. http://dx.doi.org/10.3390/cryst10110978.

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The CO2 solubilities (including CO2 Henry’s constants) and viscosities in ionic liquids (ILs)/deep eutectic solvents (DESs)-based hybrid solvents were comprehensively collected and summarized. The literature survey results of CO2 solubility illustrated that the addition of hybrid solvents to ILs/DESs can significantly enhance the CO2 solubility, and some of the ILs-based hybrid solvents are super to DESs-based hybrid solvents. The best hybrid solvents of IL–H2O, IL–organic, IL–amine, DES–H2O, and DES–organic are [DMAPAH][Formate] (2.5:1) + H2O (20 wt %) (4.61 mol/kg, 298 K, 0.1 MPa), [P4444][Pro] + PEG400 (70 wt %) (1.61 mol/kg, 333.15 K, 1.68 MPa), [DMAPAH][Formate] (2.0:1) + MEA (30 wt %) (6.24 mol/kg, 298 K, 0.1 MPa), [TEMA][Cl]-GLY-H2O 1:2:0.11 (0.66 mol/kg, 298 K, 1.74 MPa), and [Ch][Cl]-MEA 1:2 + DBN 1:1 (5.11 mol/kg, 298 K, 0.1 MPa), respectively. All of these best candidates show higher CO2 solubility than their used pure ILs or DESs, evidencing that IL/DES-based hybrid solvents are remarkable for CO2 capture. For the summarized viscosity results, the presence of hybrid solvents in ILs and DESs can decrease their viscosities. The lowest viscosities acquired in this work for IL–H2O, IL–amine, DES–H2O, and DES–organic hybrid solvents are [DEA][Bu] + H2O (98.78 mol%) (0.59 mPa·s, 343.15 K), [BMIM][BF4] + DETA (94.9 mol%) (2.68 mPa·s, 333.15 K), [L-Arg]-GLY 1:6 + H2O (60 wt %) (2.7 mPa·s, 353.15 K), and [MTPP][Br]-LEV-Ac 1:3:0.03 (16.16 mPa·s, 333.15 K) at 0.1 MPa, respectively.

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Chao, Lingfeng, Tingting Niu, Hao Gu, Yingguo Yang, Qi Wei, Yingdong Xia, Wei Hui et al. « Origin of High Efficiency and Long-Term Stability in Ionic Liquid Perovskite Photovoltaic ». Research 2020 (10 septembre 2020) : 1–13. http://dx.doi.org/10.34133/2020/2616345.

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Environment-friendly protic amine carboxylic acid ionic liquids (ILs) as solvents is a significant breakthrough with respect to traditional highly coordinating and toxic solvents in achieving efficient and stable perovskite solar cells (PSCs) with a simple one-step air processing and without an antisolvent treatment approach. However, it remains mysterious for the improved efficiency and stability of PSCs without any passivation strategy. Here, we unambiguously demonstrate that the three functions of solvents, additive, and passivation are present for protic amine carboxylic acid ILs. We found that the ILs have the capability to dissolve a series of perovskite precursors, induce oriented crystallization, and chemically passivate the grain boundaries. This is attributed to the unique molecular structure of ILs with carbonyl and amine groups, allowing for strong interaction with perovskite precursors by forming C=O…Pb chelate bonds and N-H…I hydrogen bonds in both solution and film. This finding is generic in nature with extension to a wide range of IL-based perovskite optoelectronics.

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Walvekar, Rashmi, Zulkefly Mohammad Afiq, Suganti Ramarad et Siddiqui Khalid. « Devulcanization of Waste Tire Rubber Using Amine Based Solvents and Ultrasonic Energy ». MATEC Web of Conferences 152 (2018) : 01007. http://dx.doi.org/10.1051/matecconf/201815201007.

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This research project focuses on an alternative pathway of devulcanizing waste tire rubber by using amine based chemicals. Waste tire rubbers are known to be as toxic, non-degradable material due to their vulcanized crosslink carbon structure, and disposing of such waste could impose hazardous impacts on the environment. The current rubber recycling methods that are practiced today are rather uneconomical, non-environmentally friendly, and also producing recycled rubber with low quality due to the alteration in the main polymeric chains of waste rubber. This project aims to answer the question of whether the usage of amine can produce high quality rubber, where the properties of recycled rubber is almost the same as new/virgin rubber. With known potential of amine, it is a challenge for the chemical to selectively cleave the sulfur bonds without affecting the main carbon backbone chain in the rubber structure and diminishing much of the rubber properties. To study this research, amine-treated rubber must undergo devulcanisation process by applying heat and sonication energy. Then, the properties of the amine-treated rubber were determined through a set of characterization tests and analysis which are: gel content test to determine the weight of rubber before and after devulcanization, the thermogravimetric analysis (TGA) to determine the thermal degradation and stability of rubber, and Fourier Transform Infrared Spectroscopy (FTIR) to determine any structural change of the rubber. In this research so far, the first two preliminary analysis tests have been performed. The gel content test has shown that tertiary amine samples possessed a lower gel content (%) of (77 – 63 %), compared to primary amine samples (falls within the range of 80%), as well as the TGA test in which tertiary amine samples degrade faster than primary amine samples (suggesting a higher degree of rubber structure breakdown). For each type of amine, the concertation of amine did not play a major role in affecting the degree of devulcanization (as the concentration increased, the degree of devulcanization decreased for some samples). FTIR analysis showed that only sulphur-sulphur bonds were cleaved during the devulcanization process, leaving the carbon-sulphur bonds unaffected.

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Paggiola, Giulia, Nolwenn Derrien, Jonathan D. Moseley, Anthony Green, Sabine L. Flitsch, James H. Clark, Con Robert McElroy et Andrew J. Hunt. « Application of bio-based solvents for biocatalysed synthesis of amides with Pseudomonas stutzeri lipase (PSL) ». Pure and Applied Chemistry 92, n^o 4 (28 avril 2020) : 579–86. http://dx.doi.org/10.1515/pac-2019-0808.

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AbstractBio-based solvents were investigated for the biocatalysed amidation reactions of various ester-amine combinations by Pseudomonas stutzeri lipase (PSL). Reactions were undertaken in a range of green and potentially bio-based solvents including terpinolene, p-cymene, limonene, 2-methyl THF, ɣ-valerolactone, propylene carbonate, dimethyl isosorbide, glycerol triacetate and water. Solvent screenings demonstrated the importance and potential of using non-polar bio-based solvents for favouring aminolysis over hydrolysis; whilst substrate screenings highlighted the unfavourable impact of reactants bearing bulky para- or 4-substituents. Renewable terpene-based solvents (terpinolene, p-cymene, D-limonene) were demonstrated to be suitable bio-based media for PSL amidation reactions. Such solvents could provide a greener and more sustainable alternative to traditional petrochemical derived non-polar solvents. Importantly, once the enzyme (either PSL or CALB) binds with a bulky para-substituted substrate, only small reagents are able to access the active site. This therefore limits the possibility for aminolysis to take place, thereby promoting the hydrolysis. This mechanism of binding supports the widely accepted ‘Ping Pong – Bi Bi’ mechanism used to describe enzyme kinetics. The work highlights the need to further investigate enzyme activity in relation to para- or 4-substituted substrates. A priority in PSL chemistry remains a methodology to tackle the competing hydrolysis reaction.

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Mammadova, S. R. « Pd(II) extraction from acid solutions by bis-(2-hidroxyl-5-alkylbenzyl)amine ». Bulletin of the Karaganda University. "Chemistry" series 102, n^o 2 (30 juin 2021) : 24–30. http://dx.doi.org/10.31489/2021ch2/24-30.

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It isknown that a series oforganiccompoundscontained in the molecule SH, NH qroups have theabilityto formtheintracomplex compounds under certain conditions. These compounds allowto carryoutthe extraction in acidic mediumandthereforepreventthehydrolysis process. They are not dissolved in water but are soluble in various solvents and form colored solutions and so may be used in extraction chemistry. The main purpose of this paper was to study the ability to extract palladium by bis-(2-hidroxyl-5-alkylbenzyl)amine, synthesized in the laboratory on the basis of industrial alkylphenols. Ammonium acetate with various pH wasused as a buffer to extract palladiumfromPdCl2·2H2O0.1 mkg/ml solution. The main task for theuse of inert organic compound in extraction is the selection of a reagent which dissolves it but does not form any compound. For this purpose the influence of different solvents on this reagent was researched. The experiments show that bis-(2-hidroxyl-5-alkylbenzyl)amine is dissolved well in organic solvents. Itssolution, for examplein kerosene, is light-resistant, does not hydrolyze in water, alkalis and acids.Thus bis-(2-hidroxyl-5-alkylbenzyl)amine may be recomended for palladium extraction.

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