scholarly journals BIOCATALYTIC SYNTHESIS OF D-GLUCONIC ACID

2021 ◽  
pp. 30-35
Author(s):  
Ольга Валентиновна Гребенникова ◽  
Александрина Михайловна Сульман
Keyword(s):  
Thermal Decomposition ◽  
Magnetite Nanoparticles ◽  
Gluconic Acid ◽  
Comparative Characteristic ◽  
Iron Nitrate ◽  
Native Form ◽  
Aluminum Oxides ◽  
Pharmaceutical Industries ◽  
Optimal Ph ◽  
Mesoporous Oxides

D-глюконовая кислота является широко потребляемым продуктом в пищевой и фармацевтической промышленностях. Данная работа посвящена разработке биокатализатора окисления D-глюкозы до D-глюконовой кислоты. Биокаталитические системы были выполнены на основе глюкозооксидазы, иммобилизованной на магнитоотделяемые мезопористые оксиды SiO и AlO, которые были синтезированы путем образования наночастиц магнетита в порах оксидов кремния и алюминия в результате термического разложения нитрата железа, инкорпорированного пропиткой. В работе подобраны оптимальные значения рН и температуры, при которых синтезированные биокатализаторы способны работать. Произведена сравнительная характеристика работы биокаталитических систем по сравнению с нативной формой глюкозооксидазы. D-gluconic acid is a widely consumed product in the food and pharmaceutical industries. This work is devoted to the development of a biocatalyst for the oxidation of D-glucose to D-gluconic acid. Biocatalytic systems were based on hycose oxidase immobilized on magnetically detachable mesoporous oxides SiO and AlO, which were synthesized by the formation of magnetite nanoparticles in the pores of silicon and aluminum oxides as a result of thermal decomposition of iron nitrate incorporated by impregnation. In this work, the optimal pH and temperature values were selected, at which the synthesized biocatalysts are able to work. A comparative characteristic of the work of biocatalytic systems in comparison with the native form of glucose oxidase has been made.

Preparation of Magnetite Nanoparticles by Thermal Decomposition of Hematite Powder in the Presence of Organic Solvent

2007 ◽  
Vol 998 ◽  
Author(s):  
Chun-Rong Lin ◽  
Ray-Kuang Chiang ◽  
Chih-Jung Chen ◽  
Hsin-Yi Lai ◽  
Igor S. Lyubutin ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Reaction Time ◽  
Magnetite Nanoparticles ◽  
Magnetic Measurements ◽  
Spinel Phase ◽  
Reaction Times ◽  
Transformation Process ◽  
Verwey Transition ◽  
Magnetite Particles ◽  
Xrd Patterns

ABSTRACTMagnetite nanoparticles have been synthesized by thermal decomposition of hematite (Fe2O3) powder in the presence of high boiling point solvent. The mixture of hematite and 1- octadecene solvent was heated and stirred in nitrogen gas at the temperature of 320 °C for the desired time (∼2 to 28 hrs). The influence of the reaction time on transformation process was analyzed with X-ray diffraction (XRD), Mössbauer spectroscopy (MS), and magnetic measurements. XRD patterns show that the phase of intermediate was composed of spinel phase and corundum phase (α-Fe2O3). The 57Fe Mössbauer spectra show that the spinel phase originated from the magnetite particles. The structure transformation proportion of hematite to magnetite strongly depends on reaction times. After reflux for 28 hrs the hematite-magnetite transformation was complete. The mean crystallite size of pure phase of magnetite particles is about 40 nm. The saturation magnetization increases with the reaction time, which corresponds to an increase of concentration of magnetite in the samples. A pronounced feature of the Hc and σr/σs observed in samples is the steplike change which appears at 125 K and is characteristic of the Verwey transition. The hyperfine parameters of Mössbauer spectrum measured at low temperature also indicate that the Verwey phase transition occurs. In other words, the Verwey transition is an indication that the magnetite particles exactly grew up in the synthesized compounds. This thermal decomposition process provided a method to prepare pure magnetite as well as magnetite/hematite nanocomposites useful for various magnetic applications.

Preparation and Microwave Absorbing Properties of Iron Oxides/Carbon Nanotubes Compounds

2012 ◽  
Vol 548 ◽  
pp. 133-137
Author(s):  
Chuan Guo Ma ◽  
Hai Jun Zheng ◽  
Xiao Ming Li ◽  
Liang Gao
Keyword(s):  
Thermal Decomposition ◽  
Iron Oxides ◽  
Nitrate Solution ◽  
Decomposition Temperature ◽  
Iron Nitrate ◽  
Microwave Absorbing Properties ◽  
Valence States ◽  
Different Temperatures ◽  
Microwave Absorbing ◽  
Absorbing Property

A Series of iron oxides/CNTs compounds were prepared using a method of impregnation with iron nitrate solution and followed thermal decomposition. The compounds were characterized by the means of scanning electronic microscope, X-ray diffraction and thermogravimetic analysis. The dielectric and microwave-absorbing properties of EP composites containing the different compounds were further measured in a specific frequency range. The results show that: CNTs show reduction at a high temperature, and can make products of the thermal decomposition of iron nitrate produce iron oxide nanoparticles with different valence states at different temperatures. With increasing decomposition temperature, the iron oxides in CNTs composites in turn are Fe2O3, Fe3O4, FeO and Fe. Compared with pure CNTs, these iron oxides/CNTs composites have better microwave absorbing properties in the wavebands of 7.5GHz ~ 15GHz and 26.5GHz ~ 40GHz. Among those iron oxides /CNTs compounds, Fe3O4/CNTs compound has the best microwave absorbing property.

Obtaining of γ-Fe2O3 nanoparticles by thermal decomposition of polyethyleneglycol–iron nitrate mixtures

2015 ◽  
Vol 621 ◽  
pp. 61-67 ◽  
Author(s):  
Alexandra Carmen Grigorie ◽  
Cornelia Muntean ◽  
Mircea Stefanescu
Keyword(s):  
Thermal Decomposition ◽  
Iron Nitrate ◽  
Fe2o3 Nanoparticles

Studies of magnetite nanoparticles synthesized by thermal decomposition of iron (III) acetylacetonate in tri(ethylene glycol)

2009 ◽  
Vol 321 (19) ◽  
pp. 3093-3098 ◽  
Author(s):  
Dipak Maity ◽  
S.N. Kale ◽  
Ruchika Kaul-Ghanekar ◽  
Jun-Min Xue ◽  
Jun Ding
Keyword(s):  
Thermal Decomposition ◽  
Ethylene Glycol ◽  
Magnetite Nanoparticles

Synthesis of magnetite nanoparticles via a solvent-free thermal decomposition route

2009 ◽  
Vol 321 (9) ◽  
pp. 1256-1259 ◽  
Author(s):  
Dipak Maity ◽  
Shi-Guang Choo ◽  
Jiabao Yi ◽  
Jun Ding ◽  
Jun Min Xue
Keyword(s):  
Thermal Decomposition ◽  
Magnetite Nanoparticles ◽  
Solvent Free

Preparation of Magnetite Nanoparticles by Thermal Decomposition of Iron (III) Acetylacetonate with Oleic Acid as Capping Agent

2013 ◽  
Vol 737 ◽  
pp. 153-158 ◽  
Author(s):  
Agus Haryono ◽  
Sri Budi Harmami ◽  
Dewi Sondari
Keyword(s):  
Thermal Decomposition ◽  
Oleic Acid ◽  
Magnetite Nanoparticles ◽  
Industrial Wastewater ◽  
Diphenyl Ether ◽  
Organometallic Compounds ◽  
Magnetite Nanoparticle ◽  
Organometallic Precursor ◽  
Particle Size Analyzer ◽  
High Boiling Point

The thermal decomposition of organometallic compounds was used to synthesize magnetite nanoparticles in high boiling point organic solvent containing stabilizing surfactants. Iron (III) acetylacetonate was used as the organometallic precursor in this work. Thermal decomposition of cationic metal center leads directly to the metal oxide, in the presence of 1,2-hexadecanediol, oleylamine, and oleic acid in diphenyl ether. Characterization with the Particle Size Analyzer (PSA) showed the size of the obtained magnetite nanoparticles was 2.1 ± 0.9 nm with polydispersity index of 0.327. The morphology and chemical structure of the obtained magnetite nanoparticle was characterized by using of Transmition Electron Microscopy (TEM) and Fourier-Transformed Infrared (FTIR) spectroscopy. The application of magnetite nanoparticles in the industrial wastewater treatment was also discussed.

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