scholarly journals Diazonium Gold Salts as Novel Surface Modifiers: What Have We Learned So Far?

Surfaces ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 182-196 ◽  
Author(s):  
Ahmad A. L. Ahmad ◽  
Bizuneh Workie ◽  
Ahmed A. Mohamed
Keyword(s):  
Phenyl Ring ◽  
Review Paper ◽  
Molecular Nitrogen ◽  
Fine Tuning ◽  
Metal Salts ◽  
Diazonium Salts ◽  
Recent Contribution ◽  
Surface Modifiers ◽  
Gold Salts ◽  
Potential Applications

The challenges of diazonium salts stabilization have been overcome by their isolation as metal salts such as tetrachloroaurate(III). The cleavage of molecular nitrogen from diazonium salts even at very low potential or on reducing surfaces by fine tuning the substituents on the phenyl ring expanded their applications as surface modifiers in forensic science, nanomedicine engineering, catalysis and energy. The robustness of the metal–carbon bonding produced from diazonium salts reduction has already opened an era for further applications. The integration of experimental and calculations in this field catalyzed its speedy progress. This review provides a narrative of the progress in this chemistry with stress on our recent contribution, identifies potential applications, and highlights the needs in this emerging field. For these reasons, we hope that this review paper serves as motivation for others to enter this developing field of surface modification originating from diazonium salts.

Synthesis of Phosphonates via Michaelis-Arbuzov Reaction

2017 ◽  
Vol 14 (6) ◽  
pp. 883-903 ◽  
Author(s):  
Boppudi Hari Babu ◽  
Gandavaram Syam Prasad ◽  
Chamarthi Naga Raju ◽  
Mandava Venkata Basaveswara Rao
Keyword(s):  
Reaction Times ◽  
Biologically Active ◽  
Fine Tuning ◽  
Arbuzov Reaction ◽  
Reaction Conditions ◽  
Solvent Type ◽  
Potential Applications ◽  
Synthetic Methodologies ◽  
Optimal Reaction ◽  
The Arbuzov Reaction

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.

scholarly journals A Review of Different Aspects of Applying Asphalt and Bituminous Mixes under a Railway Track

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 169
Author(s):  
Kazem Jadidi ◽  
Morteza Esmaeili ◽  
Mehdi Kalantari ◽  
Mehdi Khalili ◽  
Moses Karakouzian
Keyword(s):  
High Speed ◽  
Review Paper ◽  
Railway Track ◽  
High Speed Train ◽  
Slab Track ◽  
Bituminous Mixtures ◽  
Railway Tracks ◽  
Potential Applications ◽  
Heavy Loads ◽  
Design And Construction

Asphalt is a common material that is used extensively for roadways. Furthermore, bituminous mixes have been used in railways, both as asphalt and as mortar. Different agencies and research institutes have investigated and suggested various applications. These studies indicate the benefits of bituminous material under railways, such as improving a substructure’s stiffness and bearing capacity; enhancing its dynamic characteristics and response, especially under high-speed train loads; waterproofing the subgrade; protecting the top layers against fine contamination. These potential applications can improve the overall track structure performance and lead to minimizing settlement under heavy loads. They can also guarantee an appropriate response under high-speed loads, especially in comparison to a rigid slab track. This review paper documents the literature related to the utilization of asphalt and bituminous mixes in railway tracks. This paper presents a critical review of the research in the application of asphalt and bituminous mixes in railway tracks. Additionally, this paper reviews the design and construction recommendations and procedures for asphalt and bituminous mixes in railway tracks as practiced in different countries. This paper also provides case studies of projects where asphalt and bituminous mixes have been utilized in railway tracks. It is anticipated that this review paper will facilitate (1) the exchange of ideas and innovations in the area of the design and construction of railway tracks and (2) the development of unified standards for the design and construction of railway tracks with asphalt and bituminous mixtures.

scholarly journals Hydrothermal Carbonization of Organic Waste and Biomass: A Review on Process, Reactor, and Plant Modeling

2020 ◽  
Author(s):  
Giulia Ischia ◽  
Luca Fiori
Keyword(s):  
Organic Waste ◽  
Review Paper ◽  
Recent Literature ◽  
State Of The Art ◽  
Hydrothermal Carbonization ◽  
Residual Biomass ◽  
Current State ◽  
Potential Applications ◽  
Intrinsic Complexity ◽  
Context Models

Abstract Hydrothermal carbonization (HTC) is an emerging path to give a new life to organic waste and residual biomass. Fulfilling the principles of the circular economy, through HTC “unpleasant” organics can be transformed into useful materials and possibly energy carriers. The potential applications of HTC are tremendous and the recent literature is full of investigations. In this context, models capable to predict, simulate and optimize the HTC process, reactors, and plants are engineering tools that can significantly shift HTC research towards innovation by boosting the development of novel enterprises based on HTC technology. This review paper addresses such key-issue: where do we stand regarding the development of these tools? The literature presents many and simplified models to describe the reaction kinetics, some dealing with the process simulation, while few focused on the heart of an HTC system, the reactor. Statistical investigations and some life cycle assessment analyses also appear in the current state of the art. This work examines and analyzes these predicting tools, highlighting their potentialities and limits. Overall, the current models suffer from many aspects, from the lack of data to the intrinsic complexity of HTC reactions and HTC systems. Therefore, the emphasis is given to what is still necessary to make the HTC process duly simulated and therefore implementable on an industrial scale with sufficient predictive margins. Graphic Abstract

scholarly journals Toward Non-Invasive Measurement of Atmospheric Temperature Using Vibro-Rotational Raman Spectra of Diatomic Gases

2020 ◽  
Vol 12 (24) ◽  
pp. 4129
Author(s):  
Tyler Capek ◽  
Jacek Borysow ◽  
Claudio Mazzoleni ◽  
Massimo Moraldi
Keyword(s):  
Continuous Wave ◽  
Molecular Nitrogen ◽  
Atmospheric Temperature ◽  
Precise Determination ◽  
Gas Temperature ◽  
Advantages And Disadvantages ◽  
Non Invasive ◽  
Potential Applications ◽  
532 Nm

We demonstrate precise determination of atmospheric temperature using vibro-rotational Raman (VRR) spectra of molecular nitrogen and oxygen in the range of 292–293 K. We used a continuous wave fiber laser operating at 10 W near 532 nm as an excitation source in conjunction with a multi-pass cell. First, we show that the approximation that nitrogen and oxygen molecules behave like rigid rotors leads to erroneous derivations of temperature values from VRR spectra. Then, we account for molecular non-rigidity and compare four different methods for the determination of air temperature. Each method requires no temperature calibration. The first method involves fitting the intensity of individual lines within the same branch to their respective transition energies. We also infer temperature by taking ratios of two isolated VRR lines; first from two lines of the same branch, and then one line from the S-branch and one from the O-branch. Finally, we take ratios of groups of lines. Comparing these methods, we found that a precision up to 0.1 K is possible. In the case of O2, a comparison between the different methods show that the inferred temperature was self-consistent to within 1 K. The temperature inferred from N2 differed by as much as 3 K depending on which VRR branch was used. Here we discuss the advantages and disadvantages of each method. Our methods can be extended to the development of instrumentation capable of non-invasive monitoring of gas temperature with broad potential applications, for example, in laboratory, ground-based, or airborne remote sensing.

scholarly journals Trends in a natural product fucoxanthin

2021 ◽  
Vol 38 (1) ◽  
pp. 117-124
Author(s):  
Bahar Aslanbay Güler ◽  
Esra İmamoğlu
Keyword(s):  
Chlorophyll A ◽  
Review Paper ◽  
Biological Activities ◽  
Biological Effects ◽  
Brown Seaweeds ◽  
System Protection ◽  
Potential Applications ◽  
Food And Feed ◽  
Development Characteristic ◽  
C Complex

Fucoxanthin is a xanthophyll pigment which occurs in marine brown seaweeds (macroalgae), diatoms and several microalgae species. It forms with chlorophyll a-c and several proteins, a major fucoxanthin-chlorophyll a/c complex, which transfers light energy to the photosynthesis center and plays a major role in light harvesting. Recent studies have reported that fucoxanthin has many physiological functions and biological effects, such as anti-obesity, antidiabetic, anti-inflammatory, anticancer and cardiovascular system protection. Therefore, this pigment is highly preferred for the prevention and treatment of various chronic diseases. In addition, potential applications of high value fucoxanthin can be found in cosmetic, food and feed industries. In this review paper, the historical development, characteristic properties and possible sources of fucoxanthin are extensively described. The potential biological activities of fucoxanthin are also discussed. Finally, brief overview of common applications and market analysis of commercial fucoxanthin are also reported.

Formation of Carbon Nanoscrolls During Wedge-Based Mechanical Exfoliation of HOPG

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
B. Jayasena ◽  
S. Subbiah ◽  
C. D. Reddy
Keyword(s):  
Pyrolytic Graphite ◽  
Molecular Simulations ◽  
Fine Tuning ◽  
Mechanical Exfoliation ◽  
Highly Ordered Pyrolytic Graphite ◽  
Potential Applications ◽  
Literature Evidence ◽  
Carbon Nanoscrolls ◽  
Edge Defects ◽  
Moving Wedge

Carbon nanoscrolls (CNS) of various forms are observed when highly ordered pyrolytic graphite (HOPG) is mechanically exfoliated using a wedge. We present two hypothesis of how such scrolls form. The first hypothesis is based on microscopy evidence of pre-existing folds in layer edges of the HOPG. The second hypothesis is based on the literature evidence that graphene sheets when subject to deformation can result in defects on the torn edges. The sample preparation process can induce such defects in the HOPG layers. We show using molecular simulations that the interaction of the moving wedge with certain fold geometries can trigger scroll formation, confirming the first hypothesis. To test the second hypothesis, we show using molecular simulations, that layers with edge defects, upon interacting with the moving wedge, can also form scrolls. In reality, both these factors could simultaneously cause scrolls to form. Opportunities exist in fine-tuning this wedge-based mechanical exfoliation process to synthesize CNS for use in potential applications.

A Review on Characteristics and Potential Applications of Henna Leaves (Lawsonia inermis)

2020 ◽  
Vol 17 (2) ◽  
pp. 603-612
Author(s):  
Rupashinii A/P Thana Singam ◽  
Noraini Bt Marsi ◽  
Azrin Hani Bt Abdul Rashid ◽  
Siti Hana Bt Nasir ◽  
Siti Aida Bt Ibrahim ◽  
...  
Keyword(s):  
Review Paper ◽  
Synthetic Dyes ◽  
Biological Test ◽  
Lawsonia Inermis ◽  
Textile Materials ◽  
New Antibiotics ◽  
Potential Applications ◽  
Business Week ◽  
Uv Absorbency

This review paper reports the studies available on the characteristics and applications of the henna (Lawsonia inermis) as a natural dye. Textile materials are mainly from synthetic dyes and fibers which are not renewable and not biodegradable. Around 30 million of tonnes was estimated for the global consumption of textiles and was expected to grow up to 3% per annum while 70,000 tonnes of dyes were released to the environment. The population of people who will have allergic to the chemicals will grow up to 60% by year 2020 which was stated in business week. Apart from that, natural dyes can be extracted and process from various sources such as plants, leaves, minerals, roots, barks and insect sections. Plants that was found in the world approximately 20% were for the pharmaceutical or biological test and new antibiotics were introduced in the market are obtain from natural or semi-synthetic resources. For the biological test, henna oil was tested against Staphylococcus aureus which was 870 μg/mL and Neisseria gonorrhoeae was 87 μg/mL respectively while henna leaves extraction using methanol of 95% showed significant in-vitro antihyperglycemic effect. Chemical contains in the henna are carbohydrates as 33.62%, fibers as 33.5%, fatty oils as 10–11% and essential oil as 0.01–0.02%. Moreover, the good UV absorbency for the henna dyed cotton was at 900 °C for 60 minutes and the colour fastness for the fabric which was dyed with henna is 4 which is good. Henna dye has slightly negative charge for the higher pH 9 for the washing fastness. The optimize condition for the pre-mordant is 4% for the copper sulphate (CuSO4) for cotton with the extraction of henna leaves. Furthermore, the optimum condition for the henna to remove lead Pb (II) from wastewater are pH 6, contact time is 80 minutes, 10 ppm for the initial metal concentration and 0.75 g/L for adsorbent dosage.

Balancing interactions in proline-based receptors for chiral recognition of l-/d-DOPA

2020 ◽  
Vol 18 (24) ◽  
pp. 4590-4598 ◽  
Author(s):  
Lin-E. Guo ◽  
Yu-Xin Tang ◽  
Shu-Ying Zhang ◽  
Yuan Hong ◽  
Xiao-Sheng Yan ◽  
...  
Keyword(s):  
Phenyl Ring ◽  
Fluorine Atom ◽  
Chiral Recognition ◽  
Fine Tuning ◽  
Solution Composition

Proline-based receptors for chiral recognition of l-/d-DOPA were optimized in terms of steric and electronic factors of the binding groups, together with fine tuning by introducing a fluorine atom on phenyl ring and changing solution composition.

scholarly journals Nanostructured Semiconducting Metal Oxide Gas Sensors for Acetaldehyde Detection

Chemosensors ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 56 ◽  
Author(s):  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Sang Sub Kim ◽  
Giovanni Neri
Keyword(s):  
Gas Sensors ◽  
Review Paper ◽  
Mechanical Stability ◽  
Working Mechanism ◽  
Potential Applications ◽  
Semiconducting Metal Oxides ◽  
Metal Oxide Gas Sensors ◽  
High Concentrations ◽  
Chemiresistive Gas Sensors ◽  
Semiconducting Metal Oxide

Volatile organic compounds (VOCs) are among the most abundant air pollutants. Their high concentrations can adversely affect the human body, and therefore, early detection of VOCs is of outmost importance. Among the different VOCs, in this review paper we have focused our attention to the monitoring of acetaldehyde by chemiresistive gas sensors fabricated from nanostructured semiconducting metal oxides. These sensors can not only provide a high sensing signal for detection of acetaldehyde but also high thermal and mechanical stability along with a low price. This review paper is divided into three major sections. First, we will introduce acetaldehyde as an important VOC and the importance of its detection. Then, the fundamentals of chemiresistive gas sensors will be briefly presented, and in the last section, a survey of the literature on acetaldehyde gas sensors will be presented. The working mechanism of acetaldehyde sensors, their structures, and configurations are reviewed. Finally, the future development outlook and potential applications are discussed, giving a complete panoramic view for researchers working and interested in acetaldehyde detection for different purposes in many fundamental and applicative fields.

scholarly journals The tunable electric and magnetic properties of 2D MXenes and their potential applications

2020 ◽  
Vol 1 (9) ◽  
pp. 3104-3121
Author(s):  
Vineeta Shukla
Keyword(s):  
Magnetic Properties ◽  
Magnetic Property ◽  
Review Paper ◽  
Potential Applications ◽  
Cancer Theranostics ◽  
Electromagnetic Pollution

This review paper is focused on the electrical and magnetic property based applications of MXenes such as cancer theranostics, spintronics, and shielding against electromagnetic pollution.

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