scholarly journals Electrochemical Sensors Based on the Electropolymerized Natural Phenolic Antioxidants and Their Analytical Application

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8385
Author(s):  
Guzel Ziyatdinova ◽  
Ekaterina Guss ◽  
Elvira Yakupova
Keyword(s):  
Carbon Nanomaterials ◽  
Electrochemical Sensors ◽  
Film Formation ◽  
Practical Interest ◽  
Polymeric Film ◽  
Analytical Application ◽  
Phenolic Antioxidants ◽  
Film Properties ◽  
Operational Characteristics ◽  
Wide Range

The design and fabrication of novel electrochemical sensors with high analytical and operational characteristics are one of the sustainable trends in modern analytical chemistry. Polymeric film formation by the electropolymerization of suitable monomers is one of the methods of sensors fabrication. Among a wide range of the substances able to polymerize, the phenolic ones are of theoretical and practical interest. The attention is focused on the sensors based on the electropolymerized natural phenolic antioxidants and their analytical application. The typical electropolymerization reaction schemes are discussed. Phenol electropolymerization leads to insulating coverage formation. Therefore, a combination of electropolymerized natural phenolic antioxidants and carbon nanomaterials as modifiers is of special interest. Carbon nanomaterials provide conductivity and a high working surface area of the electrode, while the polymeric film properties affect the selectivity and sensitivity of the sensor response for the target analyte or the group of structurally related compounds. The possibility of guided changes in the electrochemical response for the improvement of target compounds’ analytical characteristics has appeared. The analytical capabilities of sensors based on electropolymerized natural phenolic antioxidants and their future development in this field are discussed.

scholarly journals Different Approaches in Designing Sensitive Tools Based on Nanocomposite Materials for Biological Analytes Detection

Proceedings ◽  
2020 ◽  
Vol 57 (1) ◽  
pp. 8
Author(s):  
Ana-Maria Gurban ◽  
Petru Epure ◽  
Iuliana Răut ◽  
Mariana Călin ◽  
Nicoleta Radu ◽  
...  
Keyword(s):  
Carbon Nanomaterials ◽  
Electrochemical Sensors ◽  
Nanocomposite Materials ◽  
Polymeric Film ◽  
Complex Matrices ◽  
Screen Printed Electrodes ◽  
Physical Deposition ◽  
Biological Analytes ◽  
Screen Printed

Sensitive, stable and robust electrochemical sensors have been designed through modificationof the working electrodes with different complex matrices based on carbon nanomaterials andmetallic nanoparticles. Therefore, screen-printed electrodes were modified with complex matrices ofhybrid nanomaterials using physical deposition or entrapment in polymeric film. [...] 

Substituent Effects on the Thermal Decomposition of Phosphate Esters on Ferrous Surfaces

2019 ◽  
Author(s):  
James Ewen ◽  
Carlos Ayestaran Latorre ◽  
Arash Khajeh ◽  
Joshua Moore ◽  
Joseph Remias ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Film Formation ◽  
Substituent Effects ◽  
Vapour Phase ◽  
Industrial Applications ◽  
Phosphate Esters ◽  
Antiwear Additives ◽  
Formation Mechanisms ◽  
Phosphate Ester ◽  
Wide Range

<p>Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe<sub>3</sub>O<sub>4</sub>(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe<sub>3</sub>O<sub>4</sub>(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe<sub>3</sub>O<sub>4</sub>(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe<sub>3</sub>O<sub>4</sub>(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.</p>

scholarly journals Carbon nanomaterial hybrids via laser writing for high-performance non-enzymatic electrochemical sensors: a critical review

2021 ◽  
Author(s):  
Marcel Simsek ◽  
Nongnoot Wongkaew
Keyword(s):  
Noble Metal ◽  
Critical Review ◽  
High Performance ◽  
Carbon Nanomaterials ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Three Dimensional ◽  
Laser Writing ◽  
Enzyme Mimicking ◽  
Natural Enzyme

AbstractNon-enzymatic electrochemical sensors possess superior stability and affordability in comparison to natural enzyme-based counterparts. A large variety of nanomaterials have been introduced as enzyme mimicking with appreciable sensitivity and detection limit for various analytes of which glucose and H2O2 have been mostly investigated. The nanomaterials made from noble metal, non-noble metal, and metal composites, as well as carbon and their derivatives in various architectures, have been extensively proposed over the past years. Three-dimensional (3D) transducers especially realized from the hybrids of carbon nanomaterials either with metal-based nanocatalysts or heteroatom dopants are favorable owing to low cost, good electrical conductivity, and stability. In this critical review, we evaluate the current strategies to create such nanomaterials to serve as non-enzymatic transducers. Laser writing has emerged as a powerful tool for the next generation of devices owing to their low cost and resultant remarkable performance that are highly attractive to non-enzymatic transducers. So far, only few works have been reported, but in the coming years, more and more research on this topic is foreseeable. Graphical abstract

scholarly journals Use of simulation model for measurement of MilkRun system performance

2019 ◽  
Vol 9 (1) ◽  
pp. 600-605 ◽  
Author(s):  
Gabriel Fedorko ◽  
Martin Vasil ◽  
Michaela Bartosova
Keyword(s):  
Simulation Model ◽  
Production Systems ◽  
Operational Performance ◽  
Transport Systems ◽  
Indirect Methods ◽  
Operational Characteristics ◽  
Wide Range ◽  
Effective Operation ◽  
And Performance ◽  
Plant Simulation

AbstractIntra-plant transport systems within their operation directly impact on the performance of production systems. For their effective operation, it is, therefore, necessary to realize evaluation of operational performance and effectivity. For the realization of this type of evaluation, in addition to a wide range of sensors that can be difficult for installation and operation, we can also use indirect methods that are equally able to provide reliable operational characteristics. Indirect analytical methods are presented above all by the approach which is based on the use of simulation methods. The method of computer simulation provides a wide range of options for the evaluation of efficiency and performance. The paper describes the use of a simulation model created in the program Tecnomatix Plant Simulation for analyzing the supply of production workplaces within the MilkRun system.

scholarly journals Dispersive evaluation and surface chemistry of advanced, multifunctional silica/lignin hybrid biomaterials

2013 ◽  
Vol 11 (11) ◽  
pp. 1860-1873 ◽  
Author(s):  
Magdalena Nowacka ◽  
Łukasz Klapiszewski ◽  
Małgorzata Norman ◽  
Teofil Jesionowski
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Electrochemical Sensors ◽  
Relevant Information ◽  
Structural Features ◽  
Kraft Lignin ◽  
Morphological Properties ◽  
Wide Range ◽  
Hybrid Biomaterials

AbstractAdvanced silica/lignin hybrid biomaterials were obtained using hydrated or fumed silicas (Aerosil®200) and Kraft lignin as precursors, which is a cheap and biodegradable natural polymer. To extend the possible range of applications, the silicas were first modified with N-2-(aminoethyl)-3-aminopropyltrimethoxsysilane, and then with Kraft lignin, which had been oxidized with sodium periodate. The SiO2/lignin hybrids and precursors were characterised by means of determination of their physicochemical and dispersive-morphological properties. The effectiveness of silica binding to lignin was verified by FT-IR spectroscopy. The zeta potential value provides relevant information regarding interactions between colloid particles. Measurement of the zeta potential values enabled an indirect assessment of stability for the studied hybrid systems. Determination of zeta potential and density of surface charge also permitted the quantitative analysis of changes in surface charge, and indirectly confirmed the effectiveness of the proposed method for synthesis of SiO2/lignin hybrid materials. A particularly attractive feature for practical use is their stability, especially electrokinetic stability. It is expected that silica/lignin hybrids will find a wide range of applications (polymer fillers, biosorbents, electrochemical sensors), as they combine the unique properties of silica with the specific structural features of lignin. This makes these hybrids biomaterials advanced and multifunctional.

Polymeric film formation in spin coating

2001 ◽  
Vol 169 (1) ◽  
pp. 321-328 ◽  
Author(s):  
Aleksey Alekseev ◽  
Sergey Baturin ◽  
Georgy Pavlov ◽  
Anatoly Shiryaev
Keyword(s):  
Spin Coating ◽  
Film Formation ◽  
Polymeric Film

Bearing profile of sliding tribological systems

2021 ◽  
pp. 53-56
Author(s):  
Keyword(s):  
Hydrodynamic Lubrication ◽  
Surface Profile ◽  
Experimental Methods ◽  
Hydrodynamic Characteristics ◽  
Bearing Surface ◽  
Tabular Data ◽  
Sliding Bearing ◽  
Friction Process ◽  
Operational Characteristics ◽  
Wide Range

The main contours of the bearing surfaces of friction pairs with hydrodynamic lubrication are considered. Analysis of tabular data and graphs obtained by experimental methods made it possible to establish additional parameters of influence on the hydrodynamic characteristics of the friction process and the operational characteristics of tribological systems, in a wide range of load-speed modes. Keywords: sliding bearing, hydrodynamics, bushing, bearing surface, profile, circle, ellipse, wavy contour, wear. [email protected]

scholarly journals Barite-containing radiation protective building materials

2020 ◽  
Vol 21 (1) ◽  
pp. 94-98
Author(s):  
Nikolay V. Novikov ◽  
Svetlana V. Samchenko ◽  
Galina E. Okolnikova
Keyword(s):  
Building Materials ◽  
Protective Coatings ◽  
Relevant Literature ◽  
Cost Effective ◽  
Nuclear Facilities ◽  
Linear Absorption ◽  
Environmental Friendliness ◽  
Operational Characteristics ◽  
Wide Range ◽  
The Creation

Due to the active development of industries using nuclear technology, the creation of highly effective and cost-effective building materials for protection against hazardous ionizing radiation is of increasing interest. Widespread in the field of radiation-protective building materials are barite-containing concrete. The purpose of this article is to establish the prospects of their use in nuclear facilities, as well as to find ways to improve their technical and operational characteristics. For this an analysis of relevant literature and scientific research in the field of radiation-protective materials and, in particular, barite-containing concrete was carried out. The advantages of barite-containing concrete are high radiation-protective properties, environmental friendliness, high density, as well as economic indicators. The disadvantages are high susceptibility to shrinkage deformation and poor resistance to cyclic temperature effects. The addition of barite to the concrete composition allows to increase the coefficient of linear absorption of -rays of the material; also, with the proper selection of the composition, such material may have strength characteristics equal to or superior to the characteristics of concrete with standard compositions. Barite-containing materials have a wide range of applications and can be used both for the production of heavy concrete in the construction of load-bearing structures and in the creation of radiation-protective coatings for walls and floors.

scholarly journals Modeling of transport and technological processes of cultivation and harvesting agricultural crops

2021 ◽  
Vol 285 ◽  
pp. 07027
Author(s):  
Nikolay Maystrenko ◽  
Alexandr Levshin ◽  
Dmitriy Khort ◽  
Alexey Kutyrev
Keyword(s):  
Optimality Criterion ◽  
Practical Interest ◽  
Economic Conditions ◽  
Agricultural Crops ◽  
Agricultural Work ◽  
Technological Processes ◽  
Shift Performance ◽  
Wide Range ◽  
Optimal Values ◽  
Technological Means

The productivity of technological processes in agriculture is determined by the set of transport and technological means used. The article describes the models for the unification of shift performance, taking into account a wide range of agricultural cargoes and a large number of works on their movement in the process of cultivation and harvesting of agricultural crops. A step-by-step modeling of scenarios for the use of transport and technological means was carried out on the basis of the optimality criterion and forecasting the period of agricultural work. They confirmed that the objective function is of theoretical and practical interest, as it helps to determine the optimal values of the power of technical means, depending on the combination of production conditions. The numerical value of power obtained by calculation can serve as a guide for manufacturers of agricultural machinery in the development of promising vehicles for a specific consumer, depending on the availability of resources and production and economic conditions.

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