Prebiotic studies on the interaction of zirconia nanoparticles and ribose nucleotides and their role in chemical evolution

2021 ◽  
Vol 20 (2) ◽  
pp. 142-149
Author(s):  
Avnish Kumar Arora ◽  
Pankaj Kumar
Keyword(s):  
Electron Microscopy ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Chemical Evolution ◽  
Ribonucleic Acid ◽  
Zirconium Oxide ◽  
Origins Of Life ◽  
Neutral Ph ◽  
Interaction Studies

AbstractStudies on the interaction of biomolecules with inorganic compounds, mainly mineral surfaces, are of great concern in identifying their role in chemical evolution and origins of life. Metal oxides are the major constituents of earth and earth-like planets. Hence, studies on the interaction of biomolecules with these minerals are the point of concern for the study of the emergence of life on different planets. Zirconium oxide is one of the metal oxides present in earth's crust as it is a part of several types of rocks found in sandy areas such as beaches and riverbeds, e.g. pebbles of baddeleyite. Different metal oxides have been studied for their role in chemical evolution but no studies have been reported about the role of zirconium oxide in chemical evolution and origins of life. Therefore, studies were carried out on the interaction of ribonucleic acid constituents, 5′-CMP (cytidine monophosphate), 5′-UMP (uridine monophosphate), 5′-GMP (guanosine monophosphate) and 5′-AMP (adenosine monophosphate), with zirconium oxide. Synthesized zirconium oxide particles were characterized by using vibrating sample magnetometer, X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy. Zirconia particles were in the nanometre range, from 14 to 27 nm. The interaction of zirconium oxide with ribonucleic acid constituents was performed in the concentration range of 5 × 10−5–300 × 10−5 M. Interaction studies were carried out in three mediums; acidic (pH 4.0), neutral (pH 7.0) and basic (pH 9.0). At neutral pH, maximum interaction was observed. The interaction of zirconium oxide with 5′-UMP was 49.45% and with 5′-CMP 67.98%, while with others it was in between. Interaction studies were Langmurian in nature. Xm and KL values were calculated. Infrared spectral studies of ribonucleotides, metal oxide and ribonucleotide–metal oxide adducts were carried out to find out the interactive sites. It was observed that the nitrogen base and phosphate moiety of ribonucleotides interact with the positive charge surface of metal oxide. SEM was also carried out to study the adsorption. The results of the present study favour the important role of zirconium oxide in concentrating the organic molecules from their dilute aqueous solutions in primeval seas.

scholarly journals Nanocrystalline Metal Oxides for Methane Sensors: Role of Noble Metals

2009 ◽  
Vol 2009 ◽  
pp. 1-20 ◽  
Author(s):  
S. Basu ◽  
P. K. Basu
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Noble Metal ◽  
Gas Sensors ◽  
Noble Metals ◽  
Industrial Applications ◽  
Metal Catalyst ◽  
Nanocrystalline Metal ◽  
Sensing Properties

Methane is an important gas for domestic and industrial applications and its source is mainly coalmines. Since methane is extremely inflammable in the coalmine atmosphere, it is essential to develop a reliable and relatively inexpensive chemical gas sensor to detect this inflammable gas below its explosion amount in air. The metal oxides have been proved to be potential materials for the development of commercial gas sensors. The functional properties of the metal oxide-based gas sensors can be improved not only by tailoring the crystal size of metal oxides but also by incorporating the noble metal catalyst on nanocrystalline metal oxide matrix. It was observed that the surface modification of nanocrystalline metal oxide thin films by noble metal sensitizers and the use of a noble metal catalytic contact as electrode reduce the operating temperatures appreciably and improve the sensing properties. This review article concentrates on the nanocrystalline metal oxide methane sensors and the role of noble metals on the sensing properties.

scholarly journals The effect of metal oxide on the cure, morphology, thermal and mechanical characteristics of chloroprene and butadiene rubber blends

2019 ◽  
Vol 77 (8) ◽  
pp. 4131-4146 ◽  
Author(s):  
Aleksandra Smejda-Krzewicka ◽  
Anna Olejnik ◽  
Krzysztof Strzelec
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Cross Linking ◽  
Butadiene Rubber ◽  
Rubber Blends ◽  
Chloroprene Rubber ◽  
Index Value ◽  
Positive Effect ◽  
Very High

Abstract This paper discusses the role of metal oxides (MeO) in the cross-linking process and useful properties of chloroprene and butadiene rubber (CR/BR) blends. Iron(III) oxide (Fe2O3), iron(II,III) oxide (Fe3O4), silver(I) oxide (Ag2O) or zinc oxide were used. It has found that every proposed metal oxide can be used as a cross-linking agent of the CR/BR blends. The degree of cross-linking was evaluated by means of vulcametric parameters, equilibrium swelling in selected solvents and Mooney–Rivlin elasticity constants. The properties of the cured CR/BR products, such as tensile strength, stress at elongation, tension set under constant elongation and compression set, were also investigated. The results revealed that all CR/BR/MeO vulcanizates were characterized by a high cross-linking degree and satisfying mechanical properties. The most important advantage of obtained rubber goods is very high resistance to flame. The increase in the oxygen index value for the CR/BR/Fe2O3, CR/BR/Fe3O4 and CR/BR/Ag2O vulcanizates compared to the standard cross-linked chloroprene rubber showed that presented metal oxides provided a positive effect on the resistance to flame of the new CR/BR/MeO composites. Satisfactory properties of the studied blends are related to the presence of the interelastomer bonding of both rubbers in the compositions.

scholarly journals The Key Role of Active Sites in the Development of Selective Metal Oxide Sensor Materials

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2554
Author(s):  
Artem Marikutsa ◽  
Marina Rumyantseva ◽  
Elizaveta A. Konstantinova ◽  
Alexander Gaskov
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Active Sites ◽  
Noble Metals ◽  
Material Composition ◽  
Mixed Metal Oxides ◽  
Mixed Metal ◽  
Sensor Materials ◽  
The Impact

Development of sensor materials based on metal oxide semiconductors (MOS) for selective gas sensors is challenging for the tasks of air quality monitoring, early fire detection, gas leaks search, breath analysis, etc. An extensive range of sensor materials has been elaborated, but no consistent guidelines can be found for choosing a material composition targeting the selective detection of specific gases. Fundamental relations between material composition and sensing behavior have not been unambiguously established. In the present review, we summarize our recent works on the research of active sites and gas sensing behavior of n-type semiconductor metal oxides with different composition (simple oxides ZnO, In2O3, SnO2, WO3; mixed-metal oxides BaSnO3, Bi2WO6), and functionalized by catalytic noble metals (Ru, Pd, Au). The materials were variously characterized. The composition, metal-oxygen bonding, microstructure, active sites, sensing behavior, and interaction routes with gases (CO, NH3, SO2, VOC, NO2) were examined. The key role of active sites in determining the selectivity of sensor materials is substantiated. It was shown that the metal-oxygen bond energy of the MOS correlates with the surface acidity and the concentration of surface oxygen species and oxygen vacancies, which control the adsorption and redox conversion of analyte gas molecules. The effects of cations in mixed-metal oxides on the sensitivity and selectivity of BaSnO3 and Bi2WO6 to SO2 and VOCs, respectively, are rationalized. The determining role of catalytic noble metals in oxidation of reducing analyte gases and the impact of acid sites of MOS to gas adsorption are demonstrated.

scholarly journals Synthesis and Dissolution of Metal Oxides in Ionic Liquids and Deep Eutectic Solvents

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 78 ◽  
Author(s):  
Janine Richter ◽  
Michael Ruck
Keyword(s):  
Ionic Liquids ◽  
Low Temperature ◽  
Metal Oxide ◽  
Metal Oxides ◽  
High Temperatures ◽  
Deep Eutectic Solvents ◽  
Wide Range ◽  
Oxide Phases

Ionic liquids (ILs) and deep eutectic solvents (DESs) have proven to be suitable solvents and reactants for low-temperature reactions. To date, several attempts were made to apply this promising class of materials to metal oxide chemistry, which, conventionally, is performed at high temperatures. This review gives an overview about the scientific approaches of the synthesis as well as the dissolution of metal oxides in ILs and DESs. A wide range of metal oxides along with numerous ILs and DESs are covered by this research. With ILs and DESs being involved, many metal oxide phases as well as different particle morphologies were obtained by means of relatively simple reactions paths. By the development of acidic task-specific ILs and DESs, even difficultly soluble metal oxides were dissolved and, hence, made accessible for downstream chemistry. Especially the role of ILs in these reactions is in the focus of discussion.

Surfactant-mediated Synthesis of Functional Metal Oxide Nanostructures via Microwave Irradiation-assisted Chemical Synthesis

2009 ◽  
Vol 1174 ◽  
Author(s):  
Sanjaya Brahma ◽  
S. A. Shivashankar
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Microwave Irradiation ◽  
Chemical Synthesis ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Electron Emission ◽  
Oxide Nanostructures ◽  
Metal Oxide Nanostructures ◽  
Synthesis Procedure

AbstractNanostructured materials have attracted considerable interest in recent years due to their properties which differ strongly from their bulk phase and potential applications in nanoscale electronic and optoelectronic devices. Metal oxide nanostructures can be synthesized by variety of different synthesis techniques developed in recent years such as thermal decomposition, sol-gel technique, chemical coprecipitation, hydrothermal process, solvothermal process, spray pyrolysis, polyol process etc. All the above processes go through a tedious synthesis procedure followed by prolonged heat treatment at elevated temperature and are time consuming. In the present work we describe a rapid microwave irradiation-assisted chemical synthesis technique for the growth of nanoparticles, nanorods, and nanotubes of a variety of metal oxides in the presence of an appropriate surfactant, without the use of any templates The method is simple, inexpensive, and helps one to prepare nanostructures in a very simple way, and in a very short time, measured in minutes. The synthesis procedure employs high quality metalorganic complexes (typically -diketonates) featuring a direct metal-to-oxygen bond in its molecular structure. The complex is dissolved in a suitable solvent, often with a surfactant added, and the solution then subjected to microwave irradiation in a domestic microwave oven operating at 2.45 GHz frequency with power varying from 160-800 W, from a few seconds to a few minutes, leading to the formation of corresponding metal oxides. This method has been used successfully to synthesize nanostructures of a variety of binary and ternary metal oxides such as ZnO, CdO, Fe2O3, CuO, Ga2O3, Gd2O3, ZnFe2O4, etc. There is an observed variation in the morphology of the nanostructures with the change of different parameters such as microwave power, irradiation time, appropriate solvent, surfactant type and concentration. Cationic, anionic, nonionic and polymeric surfactants have been used to generate a variety of nanostructures. Even so, to remove the surfactant, there is either no need of heat treatment or a very brief exposure to heat suffices, to yield highly pure and crystalline oxide materials as prepared. By adducting the metal complexes, the shape of the nanostructures can be controlled further. In this manner, very well formed, single-crystalline, hexagonal nanorods and nanotubes of ZnO have been formed. Adducting the zinc complex leads to the formation of tapered ZnO nanorods with a very fine tip, suitable for electron emission applications. Particle size and their monodispersity can be controlled by a suitable choice of a precursor complex, the surfactant, and its concentration. The resulting metal oxide nanostructures have been characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, FTIR spectroscopy, photoluminescence, and electron emission measurements.

Using neutrons, X-rays and nuclear magnetism to determine the role of transition metal oxide inclusions on both glass structure and stability in automotive glass enamels

2018 ◽  
Vol 20 (20) ◽  
pp. 13734-13746
Author(s):  
Daniel T. Bowron ◽  
Jonathan Booth ◽  
Nathan S. Barrow ◽  
Patricia Sutton ◽  
Simon R. Johnson
Keyword(s):  
Phase Separation ◽  
Transition Metal ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Borosilicate Glass ◽  
Transition Metal Oxides ◽  
Glass Structure ◽  
X Rays ◽  
Low Levels

Low levels of transition metal oxides in alkali borosilicate glass systems can drastically influence crystallisation and phase separation properties.

Template-free, low temperature synthesis of binary and ternary metal oxide nanostructures

2011 ◽  
Vol 1292 ◽  
Author(s):  
Sanjaya Brahma ◽  
Pallavi Arod ◽  
S.A. Shivashankar
Keyword(s):  
Electron Microscopy ◽  
Microwave Irradiation ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Irradiation Time ◽  
Zno Nanostructures ◽  
Structure Directing Agent ◽  
Oxide Nanostructures ◽  
Metal Oxide Nanostructures ◽  
Ternary Metal

ABSTRACTWe report synthesis of some binary and ternary metal oxide nanostructures using microwave irradiation-assisted chemical synthesis, either in the presence or absence of a surfactant/structure directing agent. The method is simple, inexpensive, and yields nanoparticles of desired metal oxides in minutes, and requires no conventional templating. Nanoparticles of some functionally advanced binary/ternary metal oxides (MnO2, ZnO, CuO, ZnMn2O4 etc) have been synthesized using metal acetylacetonates as the starting precursor material and microwave as the source of energy, in a process developed in detail in our laboratory. The nanoparticle size varies from 7-50 nm. Emphasis has been placed on the synthesis of ZnO nanostructures, particularly ZnO nanoshells, which do not require any surfactant/structure-directing agent for synthesis. There is a systematic variation in the morphology of the ZnO nanostructures with variation of process parameters, such as microwave power, microwave irradiation time, type of solvents, surfactants/structure-directing agents and its type and concentration. The as-prepared powder sample may either need a very brief exposure to heat to remove the surfactant or no post-synthesis processing, and is found to be well-crystallised. Determination of their crystallinity, actual shape, and orientation was made using X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

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