Saksham Srivastava
Abstract
This is a scientific review defining the technical feasibility of surface oxidized carbon nanotubes (CNTs) for sorption of divalent metal ions (Cd 2+ , Cu 2+ , Ni 2+ , Pb 2+ , Zn 2+ ) from aqueous solution. By conducting the detailed literature review it was found that the adsorption capacities of CNTs ...
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This is a scientific review defining the technical feasibility of surface oxidized carbon nanotubes (CNTs) for sorption of divalent metal ions (Cd 2+ , Cu 2+ , Ni 2+ , Pb 2+ , Zn 2+ ) from aqueous solution. By conducting the detailed literature review it was found that the adsorption capacities of CNTs remarkably increased after conducting their surface oxidization with NaOCl, HNO3 and KMnO4 solutions. Unlike many microporous adsorbents, CNTs possess ï
Jiangang Wei;Edward Khun
Abstract
This paper investigated the determination of critical coagulation concentration using a time-resolved dynamic light scattering technique. Silicon nanoparticles were used as model nanoparticles. Zeta potential of silicon nanoparticles were quantified using a zetasizer. The key results of this study show ...
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This paper investigated the determination of critical coagulation concentration using a time-resolved dynamic light scattering technique. Silicon nanoparticles were used as model nanoparticles. Zeta potential of silicon nanoparticles were quantified using a zetasizer. The key results of this study show that critical coagulation concentration of silicon nanoparticles in NaCl is 0.2 M while critical coagulation concentration decreased to 0.01 for CaCl2 solution. This finding indicates that silicon nanoparticles are less stable in CaCl2 because of the more effective surface charge screening process occurred. This study provides information on the stability of nanoparticles in electrolyte solutions and may be served as reference in the risk assessment of nanoparticle spills into the natural aquatic systems.
Om P. Singh; N. Muhunthan; Vidya N. Singh; Bhanu P. Singh
Abstract
In this study, CZTS thin films were deposited by co-sputtering Cu, ZnS and SnS targets and sulfurizing it in H2S atmosphere at 550 °C. It has been observed that by varying the sulfurization time from 5 to 40 min, the secondary phases got eliminated and stoichiometric film is obtained. This leads ...
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In this study, CZTS thin films were deposited by co-sputtering Cu, ZnS and SnS targets and sulfurizing it in H2S atmosphere at 550 °C. It has been observed that by varying the sulfurization time from 5 to 40 min, the secondary phases got eliminated and stoichiometric film is obtained. This leads to change in the optical band gap from 1.67 to 1.51 eV. The crystallite size calculated using the broadening in the (112) peak of the X-ray diffraction spectra also changed with the sulfurization time from 15.0 to 21.7 nm. Broadening and shift in the Raman peaks have also been observed. Changes in grain size have been observed in scanning electron microscopic studies. In short, the increased band gap reported in literatures may be due to the presence of impurities (except for particles where quantum confinement is applicable; with size less than ~ 7 nm). The above conclusion is based on careful analysis of XRD and Raman data. This study shall help in characterizing CZTS thin film properly, growing high quality CZTS thin films for the realization of high efficiency and durable CZTS based solar cell.
R. P. Singh; O. S. Kushwaha
Abstract
Among all renewable sources, solar energy is the crucial zero emission renewable energy and the amount of solar energy impinging upon earth surface in one hour far exceeds the annual global energy demands. Polymer solar cells research exceeds crystalline silicon solar cells due to being inexpensive, ...
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Among all renewable sources, solar energy is the crucial zero emission renewable energy and the amount of solar energy impinging upon earth surface in one hour far exceeds the annual global energy demands. Polymer solar cells research exceeds crystalline silicon solar cells due to being inexpensive, light weight and processable into large area flexible devices. Polymer solar cells also possess high potential for power generation applications in comprehensive non-grid and grid modes. Moreover, the broad installment of polymer solar cells across the globe would certainly help to solve the problems associated with pollution, non-renewable resources, global warming and sustainability. Polymer solar cells being at present the hottest field of interdisciplinary research, there has been remarkable outcome in terms of efficiency of single-junction polymer solar cells, tandem solar cells, polymer-polymer solar cells, triple-junction polymer solar cells and solution-processed polymer solar cells. The present review briefly provides the latest breakthroughs and developments towards the efficiency and commercial aspects of various polymer solar cells.
Vardhaman V. Khedekar; Shaikh Mohammed Zaeem; Santanu Das
Abstract
Graphene-Metal oxide nanocomposites have been extensively investigated due to their potential applications in the fields of energy devices, including, solar cells, fuel cells, batteries, sensors, electro-catalysis, and photo-catalysis. Among them, several researches have been performed on supercapacitors, ...
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Graphene-Metal oxide nanocomposites have been extensively investigated due to their potential applications in the fields of energy devices, including, solar cells, fuel cells, batteries, sensors, electro-catalysis, and photo-catalysis. Among them, several researches have been performed on supercapacitors, which could be best used with devices that require high current for short duration of time. Here, in this article, we present a brief review on the recent advances on the graphene-metal oxide nanocomposites for supercapacitor technologies and the future perspective of this field of research. A wide range of graphene-metal oxide synthesis techniques have been discussed with a focus on the advancement of nanocomposites with controlled features, including, particle size, morphologies, surface structures, pore size, pore-distributions, etc. Specifically, various nanocomposites and their role in supercapacitor electrodes are discussed with their explicit electrochemical charge-storage mechanisms along with charge-transfer techniques. Furthermore, this analysis demonstrates current trends and future directions in research on graphene-metal oxide nanocomposite electrodes for the performance enhancement in next-generation supercapacitor devices.
Ramchandra Pode
Abstract
The open circuit voltage (VOC) plays a crucial role in determining the efficiency of organic solar cells. Models of the VOC based on (i) the energy difference between the LUMO of the acceptor material and the HOMO of the donor material at the heterointerface and (ii) chemical potential gradient which ...
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The open circuit voltage (VOC) plays a crucial role in determining the efficiency of organic solar cells. Models of the VOC based on (i) the energy difference between the LUMO of the acceptor material and the HOMO of the donor material at the heterointerface and (ii) chemical potential gradient which depends on the carrier mobility in a bilayer cell, are inadequate to understand the exact origin of the VOC. In this review article, the VOC in various planar and non-planar metal phthalocyanine/C60 solar cells are analyzed. These results are compared in CuPc/C60 and SubPc/C60 solar cells as a representative case of the planar and non-planar metal phthalocyanine/C60 solar cells, respectively. Regardless of unfavorable characteristics of SubPc films, the VOC value of 0.92 to 0.98V in SubPc (13 nm)/C60 (33-32.5 nm) compared to 0.44 to 0.49V in CuPc (20-40 nm)/C60 (40-30 nm) solar cells was noticed. It is suggested that the structure, morphology, and absorption properties of the evaporated film of the donor materials and the efficient separation of charges at the donor/acceptor interface in bilayer planar and non-planar metal phthalocyanine/C60 solar cells are also imperative in determining the VOC.
Navneet Phogat; Shadab Ali Khan; Shiv Shankar; Abu A. Ansary; Imran Uddin
Abstract
In modern world, engineered nanoparticles (ENPs) are increasingly becoming an important component of daily life. They are becoming an integral part of a wide range of man-made products including electronics, paints, biomedical products, sunscreens, clothing, automobiles, etc. Rapid progress in the manufacturing ...
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In modern world, engineered nanoparticles (ENPs) are increasingly becoming an important component of daily life. They are becoming an integral part of a wide range of man-made products including electronics, paints, biomedical products, sunscreens, clothing, automobiles, etc. Rapid progress in the manufacturing of ENPs and the subsequent increase in its commercial applications always have had an impact on agriculture due to the exposure of living things to these ENPs. Also, human beings are directly dependent on the plants because of their nutritional values. Hence, the impact of nanoparticles on agricultural soil and plants is always of topical interest. It is imperative to be aware of the effects of nanoparticles on soil as well as on the soil ecosystem it supports especially the soil microbes and plants; or more specifically whether they have an influence on the agricultural yield and agri-economy. It is also important to study the effects of man-made nanomaterials on the properties of agricultural soil. This work reviews some of the key features of the impact of ENPs on the environment and the fate of ENPs in agriculture.
Songjun Lia; Ashutosh Tiwari; Yi Gec; Dan Fei
Abstract
A new type of insulin delivery system capable of better self-regulating the release of insulin was reported in this study. This insulin delivery system was made of a low crosslinked insulin-imprinted hydrogel that exhibited pH-dependent interpolymer interactions between poly(methacrylic acid) (PMAA) ...
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A new type of insulin delivery system capable of better self-regulating the release of insulin was reported in this study. This insulin delivery system was made of a low crosslinked insulin-imprinted hydrogel that exhibited pH-dependent interpolymer interactions between poly(methacrylic acid) (PMAA) and poly(ethylene glycol) (PEG). At acidic conditions (such as pH 3.5), this delivery system resembled a highly crosslinked imprinted hydrogel and demonstrated a relatively slow release due to the formation of the PMAA-PEG complexes, which significantly increased physical crosslinking within the hydrogel interior and largely fixed the imprinted networks. On the contrary, at neutral or basic conditions (such as pH 7.4), this delivery system was comparable to a non-imprinted hydrogel and caused a rapid release resulting from the dissociation of the PMAA-PEG complexes. Unlike previously reported non-imprinted hydrogels and highly crosslinked imprinted polymers, which lack either molecular recognition ability or switchable imprinted networks, this unique insulin delivery system was composed of tunable and low crosslinked imprinted networks, which thereby enabled better self-regulation of insulin delivery.
Fengling Han; Xun Yi; Rebecca Yang; Ron Wakefield; Yong Feng
Abstract
This letter reviews the related research on Building Integrated Photovoltaics (BIPV) for efficient utilization of solar energy, and further clarifies the concept of networked batteries. Taking Lithium-ion batteries as an example, maximizing the energy storage is the target, which is achieved by managing ...
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This letter reviews the related research on Building Integrated Photovoltaics (BIPV) for efficient utilization of solar energy, and further clarifies the concept of networked batteries. Taking Lithium-ion batteries as an example, maximizing the energy storage is the target, which is achieved by managing the charging and discharging of the individual batteries within a network. With the optimal management of the networked batteries, buildings constructed by using PV-capable materials are expected to be energy self-sufficient, which leads to zero-carbon energy supply. It is pointed out that the real-time estimation on the State-of-Charge (SoC) of Lithium-ion battery is crucial for secure management of the networked batteries.
S. A. Acharya; K. Singh
Abstract
Dielectric behaviour and ionic conductivity of nanostructured Ce0.9Gd0.1O2-d(GDC) are investigated to probe morphology influence of grains on ion transport mechanism at microscopic level. GDC are synthesized in two different morphologies of grains (rod-shape and round-shape particles). TEM study confirmed ...
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Dielectric behaviour and ionic conductivity of nanostructured Ce0.9Gd0.1O2-d(GDC) are investigated to probe morphology influence of grains on ion transport mechanism at microscopic level. GDC are synthesized in two different morphologies of grains (rod-shape and round-shape particles). TEM study confirmed shape and size; diameter of rods are observed around 20 nm and length are in range of 50-100 nm, while diameter of round particles are found about 10 nm. The dielectric behaviour is studied using the dielectric functions such as dielectric permittivity (e’) and electric modulus (M”). The ionic conductivity is studied by temperature dependent impedance spectra. Both these properties are observed to be finely manipulative by morphology and size. Activation energy of charge carrier relaxation and charge carrier orientation are calculated from impedance spectra and electric modulus spectra and are found to be more in rod-shape GDC. Dielectric relaxation times are also observed to be more for GDC rods. This study provides clear evidence that grain shape and size affect on dopant-oxygen vacancies ineraction, which affect on ion migration and hence ionic conductivity. 1D morphology of grains in oxy-ion conductor has high potential to enhance ionic conductivity.
Ingemar Lundstrom
Abstract
I would like to congratulate the Editors for this impressive collection of contributions on the front line of nanomaterial research. The volume covers both fundamental materials science and innovative applications of nanomaterials. The different chapters with their extensive reference lists should serve ...
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I would like to congratulate the Editors for this impressive collection of contributions on the front line of nanomaterial research. The volume covers both fundamental materials science and innovative applications of nanomaterials. The different chapters with their extensive reference lists should serve as extremely good sources for new as well as already established researchers in the area. The whole book or parts of it may also serve as a text for Ph.D. and master courses on nanomaterials. Almost any “intelligent nanomaterial” can be found in the volume and some are described in several of the chapters. Perhaps, I would have expected to find more entrances to graphene, one of the “intelligent nanomaterials” of our time. This little remark cannot blur the fact, however, that Intelligent Nanomaterials, edited by Tiwari, Mishra, Kobayashi and Turner, is an exceptionally valuable reference book for many researchers and students in materials science, nano- and biotechnology.
Jia-Jia Shen; Jia He; Ya Ding
Abstract
Gold nanoparticles (GNPs) are of unique and interesting materials being firstly reported 100 years ago. They are one of the most widely studied nanomaterials potential for disease cure. To improve the colloidal stability, biocompatibility, and hemocompatibility of GNPs, chitosan (CS), a naturally produced ...
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Gold nanoparticles (GNPs) are of unique and interesting materials being firstly reported 100 years ago. They are one of the most widely studied nanomaterials potential for disease cure. To improve the colloidal stability, biocompatibility, and hemocompatibility of GNPs, chitosan (CS), a naturally produced polysaccharide with excellent biocompatibility and biodegradation, has been modified to generate water-soluble derivatives and used as the stabilizing agent of GNPs. In the presence of these derivatives, GNPs are stabilized, functionalized, and assembled via electronic static and covalent bond interactions. Based on these works, GNPs with different dimensional, morphology, and crystal lattice are obtained, which can be further apply to a variety of applications in sensing, imaging, therapy, and catalysis.
Abstract
The name Anthony P. F. Turner, biosensor pioneer, is often considered synonymous with his chosen field. This 5th June will be his 61st birthday. We track here his professional footprint, in order to celebrate his upcoming birthday and to commemorate his 31-years of dedication to biosensors. Commemorating ...
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The name Anthony P. F. Turner, biosensor pioneer, is often considered synonymous with his chosen field. This 5th June will be his 61st birthday. We track here his professional footprint, in order to celebrate his upcoming birthday and to commemorate his 31-years of dedication to biosensors. Commemorating this pioneer’s achievements is a multidisciplinary celebration of his prominent contribution to biotechnology, chemistry, biomaterials and nanotechnology. Copyright © 2011 VBRI press.
Pragna Kiria; Geoff Hyett; Russell Binions
Abstract
Solid-state thermochromic materials undergo semiconductor to metal transitions at a ‘critical temperature’, Tc. This review begins by describing the phenomenon of thermochromism, whereby the optical properties of a material change reversibly as a result of a change in temperature. The various ...
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Solid-state thermochromic materials undergo semiconductor to metal transitions at a ‘critical temperature’, Tc. This review begins by describing the phenomenon of thermochromism, whereby the optical properties of a material change reversibly as a result of a change in temperature. The various different types of thermochromism will be introduced with a focus on the thermochromism exhibited by solid-state materials. The fundamental chemical principles that describe the electronic structure and properties of solids, and the chronological developments in the theory behind the thermochromic transitions (such as, the effects of electron-electron interactions and structural phase changes due to lattice distortions) that led to the discovery of the semiconductor-to-metal transition, are presented. An extensive discussion of vanadium and titanium oxides is presented with a particular focus on vanadium (IV) oxide since its transition temperature is closest to room temperature. Observations and current understanding of the nature of the semiconductor-to-metal transition exhibited by these materials is detailed. The possibility of fine-tuning the transition temperature by introducing various dopants into the vanadium (IV) oxide lattice is examined and the effects of dopant charge and size is examined. Solid-state thermochromic materials may be exploited in areas such as microelectronics, data storage, or intelligent architectural glazing, thus are required to be synthesised as thin films for use in such applications. The numerous synthetic techniques (PVD, sol-gel method, PLD, CVD, APCVD and AACVD), for making metal oxide thermochromic thin films are described in reference to the production of vanadium (IV) oxide and compared. Finally rare earth nickelates exhibiting thermochromism are described.
Amineh Ghaderi; Yugal Agrawal;Ashutosh Tiwari; Eduardo Antunez de Mayolo; Hirak Kumar Patra; Mohsen Golabi; Onur Parlak; Rickard Gunnarsson; Raul Campos; Revuri Vishnu; Sami Elhag; Selvakumar Subramanain; Wetra Yandi; Yuan Liu
Abstract
Nanoscale theragnosis is the biomedical aspect of nanomaterials for simultaneous diagnosis and therapy. The last decade was completely devoted by the scientist to combine the advancement in nanotechnology molecular biotechnology for the development of future nanomedicine. The approach started with the ...
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Nanoscale theragnosis is the biomedical aspect of nanomaterials for simultaneous diagnosis and therapy. The last decade was completely devoted by the scientist to combine the advancement in nanotechnology molecular biotechnology for the development of future nanomedicine. The approach started with the development of target-specific delivery of the cargo imaging molecule or drugs for biomedical applications. The cutting edge advantages of the nanoscale materials (e.g., large surface to volume ratio, size-shape dependent physicochemical properties and multi-functionality etc.) proved themselves as the most potential preferences to design optimal therapy for the personalized medicine. The present tutorial review will highlight the recent advances in the development on the regulation of such theragnosis system and their biomedical perspectives to act as a future nanomedicine.
Faruq Mohammad; Hamad A. Al-Lohedan; Hafiz N. Al-Haque
Abstract
Hybrid materials based on metals and natural polymers are a promising class of nanocomposites; there is an increasing interest in metal nanoparticles (NPs) due to some fascinating characteristics associated with their nanosizes such as optical, conducting, catalytic, mechanical, sensing and superparamagnetic ...
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Hybrid materials based on metals and natural polymers are a promising class of nanocomposites; there is an increasing interest in metal nanoparticles (NPs) due to some fascinating characteristics associated with their nanosizes such as optical, conducting, catalytic, mechanical, sensing and superparamagnetic properties. Despite these favorable properties, the natural tendency of NPs for aggregation, high reactivity due to surface charges, and high rate of toxicity are limiting their applicability in biomedical sector. Chitosan, a naturally available amino polysaccharide biopolymer obtained from the exoskeleton of crustaceans (crabs and shrimp) and cell walls of fungi, displays unique polycationic, porous, chelating, bioadhesive and film-forming properties. The in-built characteristics of chitosan biopolymer can be utilized to alter the negative shades of metal NPs, thereby enhancing the applications in many different areas. The incorporation of chitosan significantly affects the steric stabilization of metal colloids, creates extra functional groups for biomolecule conjugation, renders the NPs suitable for bio-markers, protects metal ions from further oxidation/reduction by means of polymer coordination and has a control over toxicity. Thus by taking advantage of the additional features offered by the combination of chitosan and metal NPs, this report is designed to provide an overview about the metal NPs type, synthesis and applications in bioengineering and biomedical sector. Starting with the influencing properties due to their combination, we further reviewed the literature related to chitosan and metal NPs applicable for medicine with a specific focus on cancer diagnosis and treatment, advanced drug delivery, tissue engineering and surgical aids, to mention some.
Eri Shima; Yoshiro Musha;Kiyoshi Itatani; Tomohiro Umeda
Abstract
Novel hemostatic agents were prepared using (i) phosphoryl oligosaccharides of calcium (POs-Ca ® 45 and POs-Ca ® 50 with calcium contents being 4.5 and 5.0 mass %, respectively), (ii) sugar-containing hydroxyapatites (s-Ca10(PO4)6(OH)2; s-HAp) obtained by the hydrolyses of POs-Ca ® 45 and ...
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Novel hemostatic agents were prepared using (i) phosphoryl oligosaccharides of calcium (POs-Ca ® 45 and POs-Ca ® 50 with calcium contents being 4.5 and 5.0 mass %, respectively), (ii) sugar-containing hydroxyapatites (s-Ca10(PO4)6(OH)2; s-HAp) obtained by the hydrolyses of POs-Ca ® 45 and POs-Ca ® 50, respectively (s-HAp(45); Ca/P ratio = 1.56, 61.2 mass % HAp and 38.8 mass % organic materials and s-HAp(50); Ca/P ratio = 1.61, 79.3 mass % HAp and 20.7 mass % organic materials), and (iii) thermoplastic resin (random copolymer of ethylene oxide (EO) and propylene oxide (PO)) (EPO). The gels formed by mixing the EPO with water (EPO/water (mass ratio): 0.20) were freeze-dried at -50 ËšC for 15 h, and then blended with POs-Ca or s-HAp ((POs-Ca or s-HAp)/EPO-EO (mass ratio): 0.2). The noted findings due to the addition of POs-Ca or s-HAp to the composite gels were: (a) the stanching time of more than 80 min due to the addition of POs-Ca ® 50 to the composite gel with EPO : EO : water = 25 : 15 : 60 (mass ratio) (25EPO-15EO) and (b) formation of osteoid at the drilled hole within the tibia and femur of Japanese white rabbits due to the addition of s-HAp(45). The combined addition of POs-Ca and s-HAp to the EPO-EO were expected to enhance the hemostasis and bone regeneration.
Ting Zhang; Liuwa Fu; Zhikang Chen; Yanyan Cui; Xiaoxuan Liu
Abstract
The latexes based on 2-(3’, 3’-Dimethyl-6-nitro-3’H-spiro[chromene-2,2’-indol]-1’-yl)ethanol(SPOH) were prepared via emulsion polymerization, using a macromolecular surfactant that copolymerized by methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA). The ...
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The latexes based on 2-(3’, 3’-Dimethyl-6-nitro-3’H-spiro[chromene-2,2’-indol]-1’-yl)ethanol(SPOH) were prepared via emulsion polymerization, using a macromolecular surfactant that copolymerized by methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA). The photochromism of the latexes was characterized by UV-vis spectroscopy. Through the characterization of DLS and SEM, the sizes and morphological of the latexes were studied before and after UV light irradiation. During the thermal fading process, it appeared continuous variable pattern in the emulsion, which was related to the rearrangement of the stimulated latexes to meet the dynamic balance of ionic strength, due to the reversible isomerization of spirogyra.
Yoshiaki Hirano; Katsutoshi Ooe; Kazuyoshi Tsuchiya; Tomohiro Hosokawa; Kazuto Koike; Shigehiko Sasa
Abstract
A health monitoring system (HMS) involving a blood extraction device with a new type of hybrid biosensor comprising an enzyme and a semiconductor has recently been developed. A MOSFET was used as the transducer. The gate electrode was extracted from the MOSFET using a cable. Gold (Au)-plate-immobilized ...
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A health monitoring system (HMS) involving a blood extraction device with a new type of hybrid biosensor comprising an enzyme and a semiconductor has recently been developed. A MOSFET was used as the transducer. The gate electrode was extracted from the MOSFET using a cable. Gold (Au)-plate-immobilized glucose oxidase (Go) was used as a biosensor and attached to the gate electrode. Go was immobilized on a self-assembled spacer combined with an Au electrode by the cross-link method using BSA as an additional bonding material. The electrode could be used to detect electrons generated by the oxidization of hydrogen peroxide produced by the reaction between Go and glucose using the constant electric current measurement system of the MOSFET-type hybrid biosensor. The sensitivities for the diluted whole blood and blood plasma were 61.4 and 171.2 V/(mol/L), respectively. The hybrid biosensor was useful for HMS.
B. N. Patil; S. A. Acharya
Abstract
In the present work, ZnS-Gaphene (ZnS-GNS) composite was prepared by microwave irradiation method. The prepared samples were characterized by X-ray diffraction (XRD), to confirm the formation of GNS by reducing Graphite as well as ZnS-GNS nanocomposite. Raman spectroscopy identified D and G photon vibration ...
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In the present work, ZnS-Gaphene (ZnS-GNS) composite was prepared by microwave irradiation method. The prepared samples were characterized by X-ray diffraction (XRD), to confirm the formation of GNS by reducing Graphite as well as ZnS-GNS nanocomposite. Raman spectroscopy identified D and G photon vibration mode of GNS in the ZnS-GNS composite. X-ray photoelectrons spectra are also detected presence of graphene in ZnS. UV/VIS Spectra are studied for evaluation of photocatalytic activity. The composite is explored as photocatalysts to study dye degradation using methylene blue dye in aqueous slurry under irradiation of 663 nm wavelength. Under the same conditions the photocatalytic activity of the pure ZnS is also examined. The ZnS-GNS composite is found in enhancing the rate of photodegradation of toxic dyes as compared to pure ZnS. This Graphene based metal sulphide/oxide semiconductor nanocomposites are high potential material for Photo-degradation of toxic dyes, and act as good photocatalyst.
Yuan He; Dong Yan; Lei Shi; Shu Wang; Zhiang Xie; Huixia Luo
Abstract
Here we summarized the nanoscale layered transition metal chalcogenide superconductors, mainly based on the experimental results. In transition-metal chalcogenides the interplay between strong electron-electron and electron-phonon interactions produces a wide variety of instability ranging from charge ...
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Here we summarized the nanoscale layered transition metal chalcogenide superconductors, mainly based on the experimental results. In transition-metal chalcogenides the interplay between strong electron-electron and electron-phonon interactions produces a wide variety of instability ranging from charge density wave to superconducting state. The majority of bulk transition-metal dichalcogenides Tcs are normally between 2 and 4 K. At present, superconducting transition-metal chalcogenides generally show low transition temperature (Tc < 10 K). Fe based transition-metal chalcogenides have certain higher Tc (in the range of 10 ~ 50 K). As have been reported, nano-transition-metal chalcogenides may be one of the routes to improve the superconducting transition temperature. In this review, we would like to give a brief introduction of superconductor development and crystal structure of transition-metal chalcogenides. Furthermore, we will describe major synthesis and physical properties of nano-transition-metal chalcogenides. Finally, recent status and outlook of superconductor based on nano-transition-metal chalcogenides are discussed.
Gazala Ruhi; Haritma Chopra;Sundeep K. Dhawan; Pradeep Sambyal; Hema Bhandari
Abstract
In a novel approach, Polypyrrole/Gum Acacia composites (PPy/GA) were synthesized by in-situ oxidative polymerization of pyrrole on the Gum Acacia (GA) surface by using FeCl3 as oxidant. The 1 HNMR and FTIR confirms the presence of peaks of Polyprrole and Gum Acacia in the composite. The microstructural ...
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In a novel approach, Polypyrrole/Gum Acacia composites (PPy/GA) were synthesized by in-situ oxidative polymerization of pyrrole on the Gum Acacia (GA) surface by using FeCl3 as oxidant. The 1 HNMR and FTIR confirms the presence of peaks of Polyprrole and Gum Acacia in the composite. The microstructural analysis of the composite reveals uniform layer of Polypyrrole on the surface of GA particles. The X-ray Diffraction pattern reveals the amorphous nature of the composite. Powder coating technique was used to design the composite coatings. The electrochemical studies like Open Circuit Potential (OCP) variation with time, Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy (EIS) were conducted in 3.5% NaCl solution to evaluate the corrosion resistance of the coatings. The composite coatings demonstrated superior corrosion resistance in salt spray fog of 5.0% NaCl (under accelerated test conditions in salt spray chamber). The synergistic combination of the corrosion inhibition properties of Gum Acacia and the redox properties of Polypyrrole is the reason for the occurrence of high corrosion resistance of the composite coatings. The present coating composition has shown excellent corrosion resistance and can be a potential coating formulation for mild steel substrate used in various applications under saline conditions.
P. Muthirulan; C. K. N. Devi; M. M. Sundaram
Abstract
Simple and proficient methodology has been proposed for the preparation of hybrid photocatalyst based on titanium dioxide (TiO2)-graphene (GR) nanocomposite for acid orange 7 (AO7) dye degradation under UV irradiation. High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy ...
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Simple and proficient methodology has been proposed for the preparation of hybrid photocatalyst based on titanium dioxide (TiO2)-graphene (GR) nanocomposite for acid orange 7 (AO7) dye degradation under UV irradiation. High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy (SEM) studies revealed that TiO2 nanoparticles were uniformly dispersed on GR surface. TiO2-GR hybrid nanocomposite has also been characterized by Ultraviolet Diffusive Reflectance Spectroscopy (UV-DRS), Raman spectroscopy and X-ray diffraction (XRD) studies. Electrochemical Impedance spectroscopy (EIS) measurement revealed that the incorporation of GR with TiO2 nanoparticles significantly enhanced the electrical conductivity.The peak intensity of PL spectra of GR containing catalysts are lower than that of pristine TiO2, indicating that the electron–hole recombination rate of self-trapped excitations in TiO2 is reduced by the introduction of GR. The photocatalytic degradation measurements demonstrated that the TiO2-GR composites exhibited an enhanced photocatalytic activity for AO7 degradationunder UV irradiation compared to pure TiO2. This may due to greater adsorptivity ofdyes, extended light absorption and increased charge separation efficiency due to excellent electricalproperties of graphene and the large surface contact between graphene and TiO2 nanoparticles. Therefore, the TiO2-GR composites can be widely used as a ternary composite photocatalyst for treating the organic contaminant in the field of environmental protection.
Hongli Zhao; Zhigang Zhang; Zijun Zhao; Ronghua Yu; Yuanyuan Wan; Minbo Lan
Abstract
Novel spin-labeled magnetic nanoparticles (MNPs) were prepared through the reaction between carboxylic acids modified Fe3O4 particles and 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO). And X-ray diffractometer (XRD), FT-IR spectra, thermogravimetric analysis (TGA), transmission electronic ...
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Novel spin-labeled magnetic nanoparticles (MNPs) were prepared through the reaction between carboxylic acids modified Fe3O4 particles and 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO). And X-ray diffractometer (XRD), FT-IR spectra, thermogravimetric analysis (TGA), transmission electronic microscopy (TEM) and room temperature electron paramagnetic resonance (EPR) were employed to characterize the prepared materials. The results of EPR measurements indicated that the spin-labeled MNPs exhibited both the paramagnetism of nitroxide free radicals and superparamagnetism of ferrimagnetic nanoparticles could act as a bio-probe or potential drug delivery vehicles tracking by EPR technique.
Mikael Syv
Abstract
The world of materials science is a fascinating dimension. Findings in materials which were first made many years ago may lead to new frontiers for energy technologies. In these days of increasingly urgent needs for environmental progress, it is a pleasure for a materials scientist to explore materials ...
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The world of materials science is a fascinating dimension. Findings in materials which were first made many years ago may lead to new frontiers for energy technologies. In these days of increasingly urgent needs for environmental progress, it is a pleasure for a materials scientist to explore materials concepts with potential advances in energy and environmental, or even biomedical, engineering. Already in 1907 it was observed that there could be light emission from an indirect bandgap material namely, carborundum which is an early name of silicon carbide. This observation is referred to as the first report of a light emitting diode. Now more than 100 years after, the silicon carbide is revisited to make a rare earth metal free white LED for general lighting purpose from new insightful perspectives regarding materials synthesis and growth technology implementation.
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