scholarly journals Facile Manner in Regulating the Graphene-Shelled Structure of Cobalt Nanoparticles for the Synthesis of Amines

2021 ◽  
Author(s):  
Xiuzheng Zhuang ◽  
Jianguo Liu ◽  
Longlong Ma
Keyword(s):  
Catalytic Activity ◽  
Metallic Nanoparticles ◽  
Cost Effective ◽  
Cobalt Nanoparticles ◽  
Significant Loss ◽  
Synthesis Process ◽  
Primary Amines ◽  
Chemical Research ◽  
Wide Range ◽  
Graphitic Shell

The synthesis of pharmaceutical relevant compounds keeps close ties with the development of metalbased catalysts, which remains a common goal in chemical research to solve challenges of application, such as the deactivation of catalyst caused by its tender structure or metal leaching. In this work, we reported a simple and manageable method for the preparation of heterogeneous catalyst with stable cobalt nanoparticles that encapsulated by the outer graphitic shell, whose catalytic activity and selectivity for the synthesis of primary amines via a wide range of aldehydes (more than 52 examples), ketones (more than 26 examples), and nitriles (more than 18 examples) were proved to be broadly effective (but not all of them are shown). And also, subsequent synthesis of N, N-dimethylamine compounds following a brand-new tandem pot process by the same Co-based catalyst were simultaneously explored. In most cases, the Co-based catalyst enables easy substitution of –NH2 moiety towards functionalized and structurally diverse molecules under very mild industrially viable and scalable conditions, providing cost-effective access to numerous amines and other precursors for more complex drug products. More surprisingly, the Co-based catalyst can also be easily recycled due to its intrinsic magnetism and still remains excellent catalytic activity and selectivity for the target products even after reusing up to twelve times. Results from analytic technologies, including but not limited to XRD, XPS, TEM/Mapping and in-suit FTIR, reveals that the structural features of catalyst are closely in relation to its catalytic mechanisms; in simple terms, the outer graphitic shell is activated by the electronic interactions between the inner metallic nanoparticles and the carbon layer as well as the induced charge redistribution. Except for the gram-scale batch test in laboratory, we have firstly evaluated the lifecycle of Co-based catalyst on an automatic hydrogenation reactor by employing continuous flows of reactant (5 ml/min, react within 1.6 min) under the similar conditions (90 °C, 3 MPa H2, 0.1 mol/L), whose results suggests the theoretically minimal lifecycle of Co-based catalyst can reach a continuous period of 72 h without any significant loss of catalytic efficiency. In conclusion, the advantages of this newly developed method involving operational simplicity, high stability, easily recyclable, cost-effective of the catalyst, and good functional group compatibility for the synthesis of functional amines, as well as the highly efficient and industrial applicable tandem synthesis process. <br>

scholarly journals Facile Manner in Regulating the Graphene-Shelled Structure of Cobalt Nanoparticles for the Synthesis of Amines

2021 ◽  
Author(s):  
Xiuzheng Zhuang ◽  
Jianguo Liu ◽  
Longlong Ma
Keyword(s):  
Catalytic Activity ◽  
Metallic Nanoparticles ◽  
Cost Effective ◽  
Cobalt Nanoparticles ◽  
Significant Loss ◽  
Synthesis Process ◽  
Primary Amines ◽  
Chemical Research ◽  
Wide Range ◽  
Graphitic Shell

The synthesis of pharmaceutical relevant compounds keeps close ties with the development of metalbased catalysts, which remains a common goal in chemical research to solve challenges of application, such as the deactivation of catalyst caused by its tender structure or metal leaching. In this work, we reported a simple and manageable method for the preparation of heterogeneous catalyst with stable cobalt nanoparticles that encapsulated by the outer graphitic shell, whose catalytic activity and selectivity for the synthesis of primary amines via a wide range of aldehydes (more than 52 examples), ketones (more than 26 examples), and nitriles (more than 18 examples) were proved to be broadly effective (but not all of them are shown). And also, subsequent synthesis of N, N-dimethylamine compounds following a brand-new tandem pot process by the same Co-based catalyst were simultaneously explored. In most cases, the Co-based catalyst enables easy substitution of –NH2 moiety towards functionalized and structurally diverse molecules under very mild industrially viable and scalable conditions, providing cost-effective access to numerous amines and other precursors for more complex drug products. More surprisingly, the Co-based catalyst can also be easily recycled due to its intrinsic magnetism and still remains excellent catalytic activity and selectivity for the target products even after reusing up to twelve times. Results from analytic technologies, including but not limited to XRD, XPS, TEM/Mapping and in-suit FTIR, reveals that the structural features of catalyst are closely in relation to its catalytic mechanisms; in simple terms, the outer graphitic shell is activated by the electronic interactions between the inner metallic nanoparticles and the carbon layer as well as the induced charge redistribution. Except for the gram-scale batch test in laboratory, we have firstly evaluated the lifecycle of Co-based catalyst on an automatic hydrogenation reactor by employing continuous flows of reactant (5 ml/min, react within 1.6 min) under the similar conditions (90 °C, 3 MPa H2, 0.1 mol/L), whose results suggests the theoretically minimal lifecycle of Co-based catalyst can reach a continuous period of 72 h without any significant loss of catalytic efficiency. In conclusion, the advantages of this newly developed method involving operational simplicity, high stability, easily recyclable, cost-effective of the catalyst, and good functional group compatibility for the synthesis of functional amines, as well as the highly efficient and industrial applicable tandem synthesis process. <br>

scholarly journals Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

2021 ◽  
Vol 22 (7) ◽  
pp. 3316
Author(s):  
Carlos Sainz-Urruela ◽  
Soledad Vera-López ◽  
María Paz San San Andrés ◽  
Ana M. Díez-Pascual
Keyword(s):  
Graphene Oxide ◽  
Bioactive Compounds ◽  
Electrode Materials ◽  
Electrochemical Sensors ◽  
Chemical Properties ◽  
Cost Effective ◽  
High Specific Surface Area ◽  
Inorganic Nanoparticles ◽  
Synthesis Process ◽  
Wide Range

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.

scholarly journals Efficient, Green, and Renewable N-Di-Methylation Synthesis of Amines by a Novel Nano-Catalyst of NiNiO@C

2021 ◽  
Author(s):  
Jianguo Liu ◽  
Yanpei Song ◽  
Xiuzheng Zhuang ◽  
Mingyue Zhang ◽  
Longlong Ma
Keyword(s):  
Cost Effective ◽  
Synthesis Process ◽  
Primary Amines ◽  
Selective Synthesis ◽  
One Pot ◽  
Highly Efficient ◽  
General Chemical ◽  
Nano Catalyst ◽  
Earth Abundant ◽  
Tandem Synthesis

<p><a></a><a>The development of Earth-abundant reusable and no-toxic heterogeneous catalyst applied in the pharmaceutically, bio-active relevant compounds synthesis as well as other organic syntheses still remains as the most important goal of the general chemical research. N-methylated compounds, as one of the most essential bioactive compounds,</a> have been widely used in the fine and bulk industries for the production of high-value chemicals including pharmaceuticals, agrochemicals, and dyes. As their reports, activated toxic methyl iodide and dimethyl sulfoxide were usually employed in the traditional N-methylation, which easily suffer from narrow scopes of amines, generation of by-products, and a large amount of waste. <a>Very recently, </a>transition metal-catalyzed methylation of amines has become an efficient, practical, and cost-effective method for the one-pot selective synthesis of N-methylamines with C<sub>1</sub> sources. Herein, we first developed a simple and <a>environmentally friendly</a> method for the preparation of efficient, reusable, and low-cost graphene spheres encapsulated Ni/NiO nanoalloy catalysts (Ni/NiO@C) for highly selective synthesis of the N-methylated compounds by using various functional amines and aldehydes under easily handle-able and industrially <a></a><a>applicable </a>conditions.<b> </b>A large number of primary, secondary amines (more than 70 examples) could be converted smoothly to the corresponding N, N-dimethylamines with the participation of different functional aldehydes. The gram-scale synthesis was also demonstrated in an excellent yield; not only that, the catalyst was further proved that it could be easily recycled by its intrinsic magnetism and reused up to ten times without losing activity and selectivity. Both of them are the great advantages in contrast to other catalysts reported previously. And also, for the first time, we have developed the highly efficient, cost-effective tandem synthesis of N, N-dimethylamines products in a one-pot process by means of aldehydes and NH<sub>3</sub>. As far as we know, this is the first example of the synthesis of tertiary amines with the combined reaction process of reductive amination of aldehydes and N-methylation of primary amines only with the single one earth-abundant metal catalyst. Overall, the advantages of this newly developed method including operational simplicity, high stability, easily recyclable, cost-effective of the catalyst, and good functional group compatibility for the synthesis of N-methylation products, as well as the highly efficient and industrial applicable tandem synthesis process.</p>

scholarly journals Green Synthesis of Metallic Nanoparticles: Applications and Limitations

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 902
Author(s):  
Pritam Kumar Dikshit ◽  
Jatin Kumar ◽  
Amit K. Das ◽  
Soumi Sadhu ◽  
Sunita Sharma ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Metallic Nanoparticles ◽  
Environmental Science ◽  
Cost Effective ◽  
Operating Conditions ◽  
Synthesis Methods ◽  
Comprehensive Overview ◽  
Factors Affecting ◽  
Wide Range ◽  
Range Of Functions

The past decade has witnessed a phenomenal rise in nanotechnology research due to its broad range of applications in diverse fields including food safety, transportation, sustainable energy, environmental science, catalysis, and medicine. The distinctive properties of nanomaterials (nano-sized particles in the range of 1 to 100 nm) make them uniquely suitable for such wide range of functions. The nanoparticles when manufactured using green synthesis methods are especially desirable being devoid of harsh operating conditions (high temperature and pressure), hazardous chemicals, or addition of external stabilizing or capping agents. Numerous plants and microorganisms are being experimented upon for an eco–friendly, cost–effective, and biologically safe process optimization. This review provides a comprehensive overview on the green synthesis of metallic NPs using plants and microorganisms, factors affecting the synthesis, and characterization of synthesized NPs. The potential applications of metal NPs in various sectors have also been highlighted along with the major challenges involved with respect to toxicity and translational research.

scholarly journals Efficient, Green, and Renewable N-Di-Methylation Synthesis of Amines by a Novel Nano-Catalyst of NiNiO@C

2021 ◽  
Author(s):  
Jianguo Liu ◽  
Yanpei Song ◽  
Xiuzheng Zhuang ◽  
Mingyue Zhang ◽  
Longlong Ma
Keyword(s):  
Cost Effective ◽  
Synthesis Process ◽  
Primary Amines ◽  
Selective Synthesis ◽  
One Pot ◽  
Highly Efficient ◽  
General Chemical ◽  
Nano Catalyst ◽  
Earth Abundant ◽  
Tandem Synthesis

<p><a></a><a>The development of Earth-abundant reusable and no-toxic heterogeneous catalyst applied in the pharmaceutically, bio-active relevant compounds synthesis as well as other organic syntheses still remains as the most important goal of the general chemical research. N-methylated compounds, as one of the most essential bioactive compounds,</a> have been widely used in the fine and bulk industries for the production of high-value chemicals including pharmaceuticals, agrochemicals, and dyes. As their reports, activated toxic methyl iodide and dimethyl sulfoxide were usually employed in the traditional N-methylation, which easily suffer from narrow scopes of amines, generation of by-products, and a large amount of waste. <a>Very recently, </a>transition metal-catalyzed methylation of amines has become an efficient, practical, and cost-effective method for the one-pot selective synthesis of N-methylamines with C<sub>1</sub> sources. Herein, we first developed a simple and <a>environmentally friendly</a> method for the preparation of efficient, reusable, and low-cost graphene spheres encapsulated Ni/NiO nanoalloy catalysts (Ni/NiO@C) for highly selective synthesis of the N-methylated compounds by using various functional amines and aldehydes under easily handle-able and industrially <a></a><a>applicable </a>conditions.<b> </b>A large number of primary, secondary amines (more than 70 examples) could be converted smoothly to the corresponding N, N-dimethylamines with the participation of different functional aldehydes. The gram-scale synthesis was also demonstrated in an excellent yield; not only that, the catalyst was further proved that it could be easily recycled by its intrinsic magnetism and reused up to ten times without losing activity and selectivity. Both of them are the great advantages in contrast to other catalysts reported previously. And also, for the first time, we have developed the highly efficient, cost-effective tandem synthesis of N, N-dimethylamines products in a one-pot process by means of aldehydes and NH<sub>3</sub>. As far as we know, this is the first example of the synthesis of tertiary amines with the combined reaction process of reductive amination of aldehydes and N-methylation of primary amines only with the single one earth-abundant metal catalyst. Overall, the advantages of this newly developed method including operational simplicity, high stability, easily recyclable, cost-effective of the catalyst, and good functional group compatibility for the synthesis of N-methylation products, as well as the highly efficient and industrial applicable tandem synthesis process.</p>

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

Nickel (II) and oxovanadium (IV) complexes supported on MCM-41 mesoporous and their application in catalytic selective sulfide and thiol oxidation

2020 ◽  
Vol 23 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Sol Gel ◽  
Reaction Times ◽  
Significant Loss ◽  
Spectral Studies ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Solvent Free Conditions ◽  
Mcm 41

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.

Phyto-Facilitated Bimetallic ZnFe2O4 Nanoparticles via Boswellia carteri: Synthesis, Characterization and Anti-Cancer Activity.

2020 ◽  
Vol 21 ◽  
Author(s):  
Amer Imraish ◽  
Afnan Al-Hunaiti ◽  
Tuqa Abu-Thiab ◽  
Abed Al-Qader Ibrahim ◽  
Eman Hwaitat ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Cell Lines ◽  
Metallic Nanoparticles ◽  
Bimetallic Nanoparticles ◽  
Iron Chloride ◽  
Nano Particles ◽  
Adverse Side Effect ◽  
Wide Range ◽  
Anti Cancer ◽  
Znfe2o4 Nanoparticles

Background: The growing unsatisfaction toward the available traditional chemotherapeutic agents enhanced the need to develop new methods for obtaining materials with more effective and safe anti-cancer properties. Over the past few years, usage of metallic nanoparticles has been a target for researchers of different scientific and commercial fields due to their tiny sizes, environment friendly properties and wide range applications. To overcome the obstacles of traditional physical and chemical methods for synthesis of such nanoparticles, a new less expensive and eco-friendly method has been adopted using natural existing organisms as a reducing agent to mediate synthesis of the desired metallic nanoparticles from their precursors, a process called green biosynthesis of nanoparticles. Objective: Here in the present study, zinc iron bimetallic nanoparticles (ZnFe2O4) were synthesized via an aqueous extract of Boswellia Carteri resin mixed with zinc acetate and iron chloride precursors, and they were tested for their anticancer activity. Methods: Various analytic methods were applied for the characterization of the Phyto synthesized ZnFe2O4 and they were tested for their anticancer activity against MDA-MB-231, K562, MCF-7 cancer cell lines and normal fibroblasts. Results: Our results demonstrate the synthesis of cubic structured bimetallic nanoparticles ZnFe2O4 with an average diameter 10.54 nm. MTT cytotoxicity assay demonstrate that our phyto-synthesized ZnFe2O4 nanoparticles exhibited a selective and potent anticancer activity against K562 and MDA-MB-231 cell lines with IC50 values 4.53 µM and 4.19 µM, respectively. Conclusion: In conclusion, our bio synthesized ZnFe2O4 nano particles show a promising environmentally friendly of low coast chemotherapeutic approach against selective cancers with a predicted low adverse side effect toward normal cells. Further in vivo advanced animal research should be done to execute their applicability in living organisms.

Green synthesis of silver nanoparticles using sustainable resources and their use as antibacterial agents: A review

2020 ◽  
Vol 13 ◽  
Author(s):  
Kumari Jyoti ◽  
Punyasloka Pattnaik ◽  
Tej Singh
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extracts ◽  
Metallic Nanoparticles ◽  
Cost Effective ◽  
Biological Properties ◽  
Metal Species ◽  
Sustainable Resources ◽  
Research Areas ◽  
Low Toxicity

Background:: Synthesis of metallic nanoparticles has attracted extensive vitality in numerous research areas such as drug delivery, biomedicine, catalysis etc. where continuous efforts are being made by scientists and engineers to investigate new dimensions for both technological and industrial advancements. Amongst numerous metallic nanoparticles, silver nanoparticle (AgNPs) is a novel metal species with low toxicity, higher stability and significant chemical, physical and biological properties. Methods:: In this, various methods for the fabrication of AgNPs are summarized. Importantly, we concentrated on the role of reducing agents of different plants parts, various working conditions such as AgNO3 concentration; ratio of AgNO3/extract; incubation time; centrifugal conditions, size and shapes. Results:: This study suggested that eco-friendly and non toxic biomolecules present in the extracts (e.g. leaf, stem and root) of plants are used as reducing and capping agents for silver nanoparticles fabrication. This method of fabrication of silver nanoparticles using plants extracts is comparatively cost-effective and simple. A silver salt is simply reduced by biomolecules present in the extracts of these plants. In this review, we have emphasized the synthesis and antibacterial potential of silver nanoparticles using various plant extracts. Conclusion:: Fabrication of silver nanoparticles using plant extracts have advantage over the other physical methods, as it is safe, eco-friendly and simple to use. Plants have huge potential for the fabrication of silver nanoparticles of wide potential of applications with desired shape and size.

The Future of Plasma-Based Surface Engineering Techniques in Tribology (Keynote)

2005 ◽  
Author(s):  
Allan Matthews ◽  
Adrian Leyland
Keyword(s):  
Surface Engineering ◽  
Performance Enhancement ◽  
Bulk Material ◽  
Cost Savings ◽  
Cost Effective ◽  
Ceramic Coatings ◽  
Performance Improvements ◽  
Treatment Techniques ◽  
Wide Range ◽  
Macro Scale

Over the past twenty years or so, there have been major steps forward both in the understanding of tribological mechanisms and in the development of new coating and treatment techniques to better “engineer” surfaces to achieve reductions in wear and friction. Particularly in the coatings tribology field, improved techniques and theories which enable us to study and understand the mechanisms occurring at the “nano”, “micro” and “macro” scale have allowed considerable progress to be made in (for example) understanding contact mechanisms and the influence of “third bodies” [1–5]. Over the same period, we have seen the emergence of the discipline which we now call “Surface Engineering”, by which, ideally, a bulk material (the ‘substrate’) and a coating are combined in a way that provides a cost-effective performance enhancement of which neither would be capable without the presence of the other. It is probably fair to say that the emergence and recognition of Surface Engineering as a field in its own right has been driven largely by the availability of “plasma”-based coating and treatment processes, which can provide surface properties which were previously unachievable. In particular, plasma-assisted (PA) physical vapour deposition (PVD) techniques, allowing wear-resistant ceramic thin films such as titanium nitride (TiN) to be deposited on a wide range of industrial tooling, gave a step-change in industrial productivity and manufactured product quality, and caught the attention of engineers due to the remarkable cost savings and performance improvements obtained. Subsequently, so-called 2nd- and 3rd-generation ceramic coatings (with multilayered or nanocomposite structures) have recently been developed [6–9], to further extend tool performance — the objective typically being to increase coating hardness further, or extend hardness capabilities to higher temperatures.

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