scholarly journals Микроволновый синтез ортоферрита иттрия и допирование его никелем

2019 ◽  
Vol 21 (2) ◽  
pp. 306-312
Author(s):  
Elena V. Tomina ◽  
Nikolay A. Kurkin ◽  
Sergei A. Mal’tsev
Keyword(s):  
Inorganic Chemistry ◽  
Sol Gel ◽  
Functional Materials ◽  
Microstructural Characterization ◽  
Inorganic Materials ◽  
Nanocrystalline Powders ◽  
Hydrothermal Conditions ◽  
Yttrium Orthoferrite ◽  
Characterization Of Materials ◽  
Glycine Nitrate Combustion

Установлено активирующее действие микроволнового излучения в процессе синтеза нанопорошков ортоферрита иттрия, допированного никелем, заключающеесяв значительном увеличении скорости процесса, снижении температуры отжига, высокой химической гомогенности синтезированных образцов. Реальная степень допирования согласно результатам локального рентгеноспектрального микроанализа оказалась несколько ниже номинальной, максимальная реальная степень допирования составляет 0.12. Средний размер частиц YFeO3 и NiхY1-хFeO3 находится в диапазоне 200–300 нм.   REFERENCES Popkov V. I., Almjasheva O. V. Yttrium orthoferrite YFeO3 nanopowders formation under glycine-nitrate combustion conditions. Russian Journal of Applied Chemistry, 2014, v. 87(2), pp. 167-171. https://doi.org/10.1134/S1070427214020074 Letyuk L. M., Kostishin V. G., Gonchar A. V. Tekhnologiya ferritovykh materialov magnitoelektroniki [Technology of ferrite materials of magnetoelectronics]. Moscow, MISiS Publ., 2005, 352 p. (in Russ.) Petrova E., Kotsikau D., Pankov V. Structural characterization and magnetic properties of sol–gel derived ZnxFe3-xO4 Journal of Magnetism and Magnetic Materials, 2015, v. 378, pp, 429–435. https://doi.org/10.1016/j.jmmm.2014.11.076 Mittova I. Ya., Tomina E. V., Lavrushina S. S. Nanomaterialy: sintez nanokristallicheskikh poroshkov i poluchenie kompaktnykh nanokristallicheskikh materialov: uchebnoe posobie dlya vuzov [Nanomaterials: the synthesis of nanocrystalline powders and the production of compact nanocrystalline materials: a textbook for universities]. Voronezh, LOP VGU Publ., 2007, 35 p. (in Russ.) Brandon D., Kaplan W. Microstructural Characterization of Materials. Chichester: John Wiley & Sons Ltd, 1999, 424 p. Tretyakov Yu. D. Development of inorganic chemistry as a fundamental for the design of new generations of functional materials. Russian Chemical Reviews, 2004, v. 73(9), pp. 831–846. https://doi.org/10.1070/RC2004v073n09ABEH000914 Tomina E. V., Mittova I. Ya., Burtseva N. A., Patent RF, N 2548089, 2015. Kuznetsova V. A., Almjasheva O. V., Gusarov V. V. Infl uence of microwave and ultrasonic treatment on the formation of CoFe2O4 under hydrothermal conditions. Glass Physics and Chemistry, 2009, v. 35(2), pp. 205–209. International Center for Diffraction Data. Shpanchenko R. V., Rozova M. G. Metodicheskaya razrabotka dlya spetspraktikuma k kursu lektsii «Prakticheskie aspekty rentgenovskoi difraktometrii» [Methodical development for the special practical course for lectures “Practical aspects of X-ray diffractometry”]. Moscow, Izd-vo Mosk. un-ta Publ., 1998, 25 p. (in Russ.) Tret’yakov Yu. D. Neorganicheskaya khimiya. Khimiya elementov: uchebnik dlya stud. vuzov, obuch. po napravleniyu 510500 “Khimiya” i spetsial’nosti 011000 “Khimiya” : v 2 t [Inorganic chemistry. Chemistry of elements: a textbook for students. universities enrolled in the direction 510500 “Chemistry” and specialization 011000 “Chemistry”: in 2 volumes]. Moscow, Izd-vo Mosk. un-ta: Akademkniga Publ., 2007, v. 1, 538 p.; v. 2, 670 p. (in Russ.) Tomina E. V., Darinskii B. M., Mittova I. Ya., Churkin V. D., Boikov N. I., Ivanova O. V. Sintez nanokristallov YСоxFe1-xO3 pod vozdeistviem mikrovolnovogo izlucheniya [Synthesis of YСоxFe1-xO3 Nanocrystals Under the Microwave Radiation], Inorganic Materials, v. 55(4), 2019, pp. 421–425. https://doi.org/10.1134/S0002337X19040158    (in Russ.)

scholarly journals Effects of Surface Functional Groups on the Adhesion of SiO2 Nanospheres to Bio-Based Materials

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1411
Author(s):  
Xiao ◽  
Xu ◽  
Niu ◽  
Zhu ◽  
Kou
Keyword(s):  
Adsorption Process ◽  
Sol Gel ◽  
Functional Materials ◽  
Inorganic Materials ◽  
Silica Nanospheres ◽  
Surface Functional Groups ◽  
Modified Silica ◽  
Adsorption Experiment ◽  
Organically Modified ◽  
Organically Modified Silica

The interactions between nanoparticles and materials must be considered when preparing functional materials. Although researchers have studied the interactions between nanoparticles and inorganic materials, little attention has been paid to those between nanoparticles and bio-based protein materials, like leather. In this study, organically modified silica nanospheres (SiO2 nanospheres) loaded with rose fragrance were prepared using (3-aminopropyl) triethoxysilane (APTES), (3-mercaptopropyl) triethoxysilane (MPTES), or 3-(2, 3-epoxypropyloxy) propyl triethoxysilane (GPTES) using the sol-gel method. To study the interactions between the modified SiO2 nanospheres and leather, a non-cross-linking adsorption experiment was conducted. According to the Dubinin–Radushkevich isotherm calculation, we found that the adsorption process of leather fiber and organically modified silica nanospheres is physical. The average adhesion energies of APTES-, MPTES-, and GPTES-modified SiO2 nanospheres on the leather are 1.34016, 0.97289, and 2.09326 kJ/mol, respectively. The weight gain, adsorption capacity, and average adhesion energy show that the modified SiO2 nanospheres can be adsorbed on leather in large quantities. The sensory evaluation confirmed that GPTES-modified SiO2 nanospheres endowed the leather with an obvious rose aroma.

scholarly journals Synthesis and characterization of nanocrystalline PZT powders: From sol to dense ceramics

2016 ◽  
Vol 10 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Ali Mirzaei ◽  
Maryam Bonyani ◽  
Shahab Torkian
Keyword(s):  
Electron Microscopy ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Microstructural Characterization ◽  
Lead Zirconate ◽  
Nanocrystalline Powders ◽  
Spectroscopic Techniques ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Dta Analysis

In this study ferroelectric lead zirconate titanate PZT (0.523/0.477) nanocrystalline powders have been successfully synthesized by an alkoxide based sol-gel process. Crystallinity of the prepared ceramic powders was studied using X-ray diffractometer. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies were performed to study morphology of the calcined powders. EDX analysis was employed to demonstrate purity of the synthesized powders. Surface nature of the powders was studied by using FTIR technique. TGA/DTA analysis was employed to study thermal behaviour of powders. Spectroscopic techniques (FTIR and XRD) results indicated that the as-dried amorphous powders can be completely crystallized at 600?C. In order to investigate the densification behaviour of the calcined powders, the crystalline PZT powders were pelletized into discs and sintered at various temperatures from 900?C to 1150?C, with a heating rate of 10?C/min and holding time of 2 h to find the optimum combination of temperature and time to produce high density ceramics. Microstructural characterization was conducted on the fractured surface of the samples using SEM. It was found that the PZT ceramics calcined at 600?C for 4 h then sintered at 1050?C for 2 h had maximal density (98% of the theoretically density).

scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

scholarly journals Amyloid fibril-directed synthesis of silica core–shell nanofilaments, gels, and aerogels

2019 ◽  
Vol 116 (10) ◽  
pp. 4012-4017 ◽  
Author(s):  
Yiping Cao ◽  
Sreenath Bolisetty ◽  
Gianna Wolfisberg ◽  
Jozef Adamcik ◽  
Raffaele Mezzenga
Keyword(s):  
Amyloid Fibril ◽  
Functional Materials ◽  
Building Blocks ◽  
Inorganic Materials ◽  
Core Shell ◽  
Shear Stresses ◽  
Bending Rigidity ◽  
Widespread Application ◽  
Nonmonotonic Dependence ◽  
Silica Core

Amyloid fibrils have evolved from purely pathological materials implicated in neurodegenerative diseases to efficient templates for last-generation functional materials and nanotechnologies. Due to their high intrinsic stiffness and extreme aspect ratio, amyloid fibril hydrogels can serve as ideal building blocks for material design and synthesis. Yet, in these gels, stiffness is generally not paired by toughness, and their fragile nature hinders significantly their widespread application. Here we introduce an amyloid-assisted biosilicification process, which leads to the formation of silicified nanofibrils (fibril–silica core–shell nanofilaments) with stiffness up to and beyond ∼20 GPa, approaching the Young’s moduli of many metal alloys and inorganic materials. The silica shell endows the silicified fibrils with large bending rigidity, reflected in hydrogels with elasticity three orders of magnitude beyond conventional amyloid fibril hydrogels. A constitutive theoretical model is proposed that, despite its simplicity, quantitatively interprets the nonmonotonic dependence of the gel elasticity upon the filaments bundling promoted by shear stresses. The application of these hybrid silica–amyloid hydrogels is demonstrated on the fabrication of mechanically stable aerogels generated via sequential solvent exchange, supercriticalCO2removal, and calcination of the amyloid core, leading to aerogels of specific surface area as high as 993m2/g, among the highest values ever reported for aerogels. We finally show that the scope of amyloid hydrogels can be expanded considerably by generating double networks of amyloid and hydrophilic polymers, which combine excellent stiffness and toughness beyond those of each of the constitutive individual networks.

CuOX Films for NO2 Detection: Microstructural Characterization

2013 ◽  
Vol 481 ◽  
pp. 133-136 ◽  
Author(s):  
T.N. Myasoedova ◽  
G.E. Yalovega ◽  
N.K. Plugotarenko ◽  
M. Brzhezinskaya ◽  
V.V. Petrov ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Secondary Electron ◽  
Operating Temperature ◽  
Sol Gel ◽  
Microstructural Characterization ◽  
Temperature Treatment ◽  
Copper Oxides ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

Copper oxides films as promising materials for gas sensors applications were studied. Copper oxide films were deposited onto Si/SiO2substrates using a citrate sol-gel method with the subsequent temperature treatment at 150-5000C. These films were characterized by means of secondary electron microscopy (SEM) and X-ray-absorption near-edge structure (XANES) spectroscopy. The prepared films were utilized in NO2sensors. The dependences of the NO2response on the operating temperature and NO2concentration (10-200 ppm) were investigated. The maximum NO2response was achieved for the film annealed at 2500C.

Microstructural characterization of sol–gel derived Pb1−xLaxTiO3 ferroelectrics

2005 ◽  
Vol 388 (2) ◽  
pp. 308-313 ◽  
Author(s):  
Jun Chen ◽  
Xianran Xing ◽  
Ranbo Yu ◽  
Jinxia Deng ◽  
Guirong Liu
Keyword(s):  
Sol Gel ◽  
Microstructural Characterization

Cholesterol decorated pyridinium urea and carbamate as π-gelators for selective recognition of F- ions

2021 ◽  
Vol 05 ◽  
Author(s):  
Santanu Panja ◽  
Kumaresh Ghosh
Keyword(s):  
Sol Gel ◽  
Functional Materials ◽  
Materials Chemistry ◽  
Eye Detection ◽  
Fluoride Ions ◽  
Biologically Relevant ◽  
Design And Synthesis ◽  
Naked Eye ◽  
Visual Sensing ◽  
Naked Eye Detection

Aim: Design and synthesis of new molecules capable of forming self-assembled gels are indispensable to harvest new functional materials. Supramolecular gels have potential in many areas particularly in biology and materials chemistry. Of the different types of applications, visual sensing of biologically relevant ionic analytes is a fairly recent trend. Here we describe naked eye detection of fluoride ions involving sol-gel methodology. Methods: To execute this, cholesterol substituted pyridinium salts 1-4 have been designed and synthesized of which compounds 3 and 4 served as potential gelators for the naked eye detection of F- ions in DMSO and DMSO-H2O (1:1, v/v) respectively. Results: Gelation study reveals that not only the aromatic surface is crucial for the self-aggregation of molecules via π-π stacking interactions, but also polarity, rigidity and conformational flexibility of the molecules that govern the intermolecular association of gelators are important. Conclusion: Moreover, incorporation of fluorophores (naphthalene) as aromatic surface in the molecular designs, promotes the gelator molecules to execute sensing behavior for F- with high degree of sensitivity in solution phase also.

Cobalt-Doped Silica Organic-Inorganic Materials by Sol-Gel Method: Preparation and Thermal Stability Calcined under N2 Atmosphere

2021 ◽  
Vol 219 (1) ◽  
pp. 247-259
Author(s):  
Jing Yang ◽  
Yuzhi Ai ◽  
Wangqing Fan ◽  
Ruihua Mu ◽  
Xi Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Sol Gel ◽  
Inorganic Materials ◽  
Gel Method ◽  
Sol Gel Method ◽  
N2 Atmosphere
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