Papers by Keyword: Amination

Abstract: This study aims to synthesize, purify, and modify magnetic carbon nanofibers (Mag-CNF) into hydrophilic carbon material. The synthesis method was carried out by chemical vapor deposition (CVD) using the catalyst from Incolloy at 800°C with argon, nitrogen, hydrogen, and acetylene gases. The purification of Mag-CNF was then conducted by dissolving Mag-CNF with toluene and ethanol, followed by vacuum annealing. The hydrophilization of Mag-CNF was further performed by adding amine groups via reacting Mag-CNF with ethylene diamine, NaNO₂, and H₂SO₄. The successfully prepared Mag-CNF has characteristics of tubular tube bundles consisting of carbon nanofibers with an average diameter of 100-120 nm. The X-ray diffraction (XRD) profile shows the characteristics of carbon, iron, iron oxide, and iron carbide. The Raman spectra show the existence of D, G, and G' bands corresponding to the characteristics of carbon nanomaterials. The magnetic property characterization using a vibration sample magnetometer (VSM) shows the synthesized product as ferrimagnetic materials. The modification results show the addition of hydrophilic groups to Mag-CNF, such as O–H and N–H groups, as analyzed in Fourier Transform Infrared (FTIR) spectra. The successful hydrophilization was also visually confirmed using a dispersion test in water, showing that Mag-CNF has better dispersion after surface modification.

Abstract: The paper presents the results of the copolymerization of α-halogens of acrylic acid and N-vinylpyrrolidone in the presence of a radical initiator. The copolymerization equations are presented and activity factors are calculated. IR spectra of the obtained copolymers confirm the amination reaction. The synthesized aminated polymers form intramuscular compounds with divalent metal halides at room temperature. The kinetics of the copolymerization reaction of these systems shows that the presence of a reactive halogen atom in the structure of the copolymer has a great influence on the formation and properties of the copolymers.

Abstract: Triazole heterocyclic compounds have a wide range of applications in the fields of medicine, pesticide, energetic materials, etc. Introducing halogen atoms and amino groups into the triazole ring can obtain a series of important intermediates that can be further modified. 4,5-Dibromo-1-H-1,2,3-triazole (5), 3,5-dibromo-1-H-1,2,4-triazole (6), 3,5-dibromo-4-H-1,2,4-triazole (7) and 1-amino-4,5-dibromo-1,2,3-triazole (8), 2-amino-4,5-dibromo-1,2,3-triazole (9) and 1-amino-3,5-dibromo-1,2,4-triazole (10) were synthesized through the bromination and amination of 1,2,3-triazole (1), 1-amino-1,2,3-triazole (2), 1,2,4-triazole (3) and 4-amino-1,2,4-triazole (4). Their structures were characterized by IR, EI-MS, ESI-MS, ¹H and¹³C-NMR techniques. Single crystals of these compounds were grown by evaporation solution growth technique. The cell parameters and crystal structures were determined by X-ray single crystal diffraction studies. Among these compounds, 6 and 7, 8 and 9 were isomers, respectively. Through intermolecular hydrogen bonding, 1 forms zigzag chain structure, while 4 and 5 form cyclic trimers.

Abstract: Nowadays the development of biodiesel production as an alternative renewable energy became crucial. The reusability of enzymes as biocatalysts in biodiesel production has limitations and can be improved by the immobilization process onto the appropriate solid support, such as polyethersulfone (PES). Polyethersulfone has been synthesized utilizing microwave-assisted reaction method (400 W, 170 °C, 60 minutes). Nitration reaction of PES was performed by refluxing the synthesized PES with the mixtures of H₂SO₄ (0 °C, ± 30 minutes) and HNO₃ (25 °C, 4 hours). The –NO₂ groups of the synthesized PES-NO₂ was subsequently reduced to be PES-NH₂ using SnCl₂.2H₂O as reducing agent by reflux method (60 °C, ± 3 hours). The structure of PES and its derivatives was confirmed by FTIR and ¹H-NMR. Candida antarctica lipase was successfully immobilized onto the synthesized PES and its derivatives, which were confirmed by its FTIR spectra and its activity tests of the supernatants in hydrolyzing p-nitrophenol palmitate (pNPP) into p-nitrophenol (pNP). The results showed that the conversion percentage of pNPP to become pNP were 20.6% (free enzyme), 18.9% (PES-enzyme), and 3.7% (PES-NH₂-enzyme). The decrease in the supernatant enzyme activity showed that the enzyme has been successfully immobilized through physical adsorption onto the synthesized polymers.

Abstract: A practical method for the synthesis of 5-hydroxymethyl-2′-deoxycytidine via dithio-deoxyuridine intermediate has been developed.

Abstract: Highly ordered mesoporous carbon (CMK-3) was fabricated for the adsorption of cobalt from aqueous solutions. With the high surface area of1112.7m²/g and pore size of 17.2 nm, its abundant mesopores were benefit for providing channels for liquid propagate. In order to improve the adsorption properties,CMK-3 was modified by hydroxylation and amination. Fourier transform infrared (FTIR) spectroscopy can be seen that the amino group was successfully grafted onto the CMK-3 with highly ordered mesoporous structure. The functionalized ordered mesoporous carbon (CMK-3-EDA) ,CMK-3 and CMK-3-OX were used as absents for the adsorption of Co (II) from aqueous solution. The results showed that CMK-3-EDA were more twice effective in adsorption of Co (II) compared to CMK-3, which indicated that CMK-3-EDA had great potential for the adsorption of Co (II).

Abstract: Continuous synthesis of pyridine with (MoO₃-NiO) / Al₂O₃ has been developed. The doped NiO improved the dispersion of the MoO₃ particles and forms the new phase NiMoO₄ so that the Mo⁺⁶ particles were retained as the active sites. NiO also was found to have a great effect on the catalyst acidity. The reaction parameters were optimized and pyridine was obtained in a yield of 86.19%.

Abstract: Melamine (MA) were aminated with various primary alcohols (PA) such as lauryl alcohol(LA), octyl alcohol (OA) and monomethoxylpoly ethylene glycol (mPEG) under high-temperature and high-pressure conditions using potassium hydroxide / activated carbon (KOH/AC) as catalyst. The possible amination reaction mechanism was proposed based on FTIR, 1H NMR and fluorescence analysis of aminated products. The catalytic activity of KOH was improved remarkably by adding activated carbon as the catalyst support; and the maximum amination yield was about 95 %.

Abstract: The reaction kinetics of amination of monomethoxylpoly (ethylene glycol) (mPEG) with melamine (MA) at the molar ratio of 1:1 was studied by FTIR. This amination reaction was carried out with potassium hydroxide as reaction catalyst under high-pressure conditions at different temperature (160 °C, 170 °C, 180 °C, and 190°C) for different time (2 h, 3 h, 4 h, 5 h and 6 h). A series of melamine aminated monomethoxylpoly (ethylene glycol) (MA-mPEG) were synthesized, and the long chain of polyethylene glycol ether was grafted on the amino groups of melamine by amination. The amination kinetics parameter of reaction order and the activation energy are about 1.5 and 45 KJ/mol, respectively. In addition, the grafting amination yield increased with the number average molecular weight of mPEG at the same reaction condition.

Abstract: In order to remove formaldehyde efficiently, the activated carbon was oxidized by nitric acid and then modified by etilenodiamina. The carbon treated with nitric acid and etilenodiamina showed the significant differences in IR spectrum compare with original activated carbon. The adsorption capacity for the formaldehyde of prepared carbon and original carbon were 2.4 mg/g and 1.0 mg/g, respectively. Results demonstrate that the amino group on carbon might improve the adsorption performance of carbon for formaldehyde.