Neeraj Dilbaghi; Harmanmeet Kaur; Ritesh Kumar; Pooja Arora; Sandeep Kumar
Abstract
Nanotechnology is an interdisciplinary science comprising of various disciplines such as physics, chemistry, electronics, material science, health science, biology and veterinary science. The ability to manufacture and manipulate material at nanoscale has offered opportunities to interface biological ...
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Nanotechnology is an interdisciplinary science comprising of various disciplines such as physics, chemistry, electronics, material science, health science, biology and veterinary science. The ability to manufacture and manipulate material at nanoscale has offered opportunities to interface biological systems with outer world in new ways and with unprecedented precision. Veterinary science deals with all non human animals including wildlife and domesticated animals, livestock, working animals and companion animals. Nanotechnology has contributed in revolutionizing health and veterinary sciences by providing new tools and new materials for molecular and cellular biology that are beneficial for living organisms. The variety of nanomaterials that are used for diagnosis and treatment include metallic nanoparticle, quantum dots, carbon nanotubes, magnetic nanoparticles, fullerenes, liposomes, dendrimers and engineered hybrid nanoparticles. However, at present, little data is available on the ecotoxicological and toxicological effects associated with these nanomaterials and hence there is a need to address these issues as physiological properties of nanomaterials are expected to influence their biological response. It is believed that in the upcoming years, nanotechnology will reform the science and technology of the animal health and will help to boost up the livestock production. Nanotechnology based techniques like bioanalytical nanosensors, nanofluidics, targeted drug delivery etc has the potential to solve problems related to diagnosis and treatment of diseases. In this review, we emphasize on how nanotechnology is swiftly changing the diagnosis and treatment patterns at faster and low cost in less time duration. There can be numerous applications of nanotechnology in disease diagnosis, treatment, drug delivery, animal nutrition, animal breeding, tissue engineering and animal identity verification. The role of nanotechnology in veterinary sciences is chiefly discussed as how nanomaterials can modernize the present life.
Yongyuth Wanna; Supanit Porntheerapat;Sirapat Pratontep; Rachineewan Pui-ngam; Jitti Nukeaw; Anon Chindaduang; Gamolwan Tumcharern
Abstract
We report novel magnetic composite nanoparticles for heavy metal ion separation. Superparamagnetic iron oxide nanoparticles (SPIONs) and were coated with poly(methylmethacrylate) (PMMA) by emulsion polymerization process in the aqueous suspension of SPIONs. In addition, the hydrolysis of carboxylic functional ...
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We report novel magnetic composite nanoparticles for heavy metal ion separation. Superparamagnetic iron oxide nanoparticles (SPIONs) and were coated with poly(methylmethacrylate) (PMMA) by emulsion polymerization process in the aqueous suspension of SPIONs. In addition, the hydrolysis of carboxylic functional groups onto the PMMA-coated SPIONs was grafted with Polyethylene glycol bis(amine). Then, the functional group structures were investigated by Fourier transforms infrared spectroscopy (FTIR). The morphology of PMMA/SPIONs was determined by transmission electron microscopy (TEM) and atomic force microscope (AFM). The magnetic property was investigated by the vibrating sample magnetometer (VSM). The metal concentration in the solution after separation using the nanoparticles was determined by inductivity coupled plasma optical emission spectrometer (ICP-OES). Furthermore, we demonstrate that the efficiencies of the heavy metal ion removal for Cu(II), Mn(II), Zn(II), Cd(II), Pb(II), Co(II) and Ni(II) are 80.0 %, 57.7 %, 54.3 %, 40.0 %, 34.8 %, 32.5 % and 30.2 % by weight, respectively. The nanoparticles also exhibit some selectivity for copper, manganese and zinc. The results show that the composite nanoparticles are extremely promising for heavy metal ion separation.
Murugan Ramalingam; Ashutosh Tiwari
Abstract
Development of functional tissues often requires spatially controlled growth of cells over 2D surfaces or 3D substrates to maintain their distinct cellular functions; particularly it is essential for culturing anchorage-dependent cells. In this regard, development of new surfaces/substrates with superior ...
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Development of functional tissues often requires spatially controlled growth of cells over 2D surfaces or 3D substrates to maintain their distinct cellular functions; particularly it is essential for culturing anchorage-dependent cells. In this regard, development of new surfaces/substrates with superior surface properties that could control the cell behavior is of great important and extremely necessary for functional tissue engineering as well as to study how the cells spatially recognize and interact with synthetic material systems. Surface patterning is an approach to modify the surface of biomaterials, either chemically or topographically. Both the approaches are well demonstrated in manipulating cell behaviors such as shape, size, orientation, migration, proliferation, and differentiation. In this article, we review various commonly employed methodologies for use in patterning of biomaterial surfaces/substrates and their suitability in controlling cell behaviors.
Kumud Kant Awasthi; Rajbala Verma; Anjali Awasthi; Kamlendra Awasthi; Inderpal Soni; P. J. John
Abstract
Silver nanoparticles (Ag NPs) has resulted their incorporation into consumer products due to their extensive application in health, electronic, and household products. In particular, the oral toxicity of Ag NPs is of particular concern to ensure public health. For the present study, a genotoxic and cytotoxic ...
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Silver nanoparticles (Ag NPs) has resulted their incorporation into consumer products due to their extensive application in health, electronic, and household products. In particular, the oral toxicity of Ag NPs is of particular concern to ensure public health. For the present study, a genotoxic and cytotoxic approach was employed to elucidate the activity of 5 nm size and spherical shaped Ag NPs in liver cells of Swiss albino mice by using alkaline comet assay. Statistically significant DNA damage raise the concern about the safety associated with the applications of the Ag NPs. The result showed that Ag NPs induced a significant concentration dependent increase in the frequency of tailed nuclei (DNA damage), tail moment, %DNA in the tail, and tail length in the liver cells. Additionally significant histopathological alterations were also observed. The results of present study suggest that exposure to silver nanoparticles has the potential to cause genetic damage.
Rickard Arvidsson
Abstract
Environmentally benign production processes are required in order to ensure a sustainable graphene supply. Life cycle assessment (LCA) is an established method for assessing life cycle environmental impacts of products and production processes. In this paper, life cycle impacts of five production processes ...
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Environmentally benign production processes are required in order to ensure a sustainable graphene supply. Life cycle assessment (LCA) is an established method for assessing life cycle environmental impacts of products and production processes. In this paper, life cycle impacts of five production processes for graphene are reviewed: Chemical reduction of graphite oxide, ultrasonication exfoliation, thermal exfoliation, chemical vapour deposition, and epitaxial growth. The reduction step, including the production of the reduction agent hydrazine, was the main contributor for most impacts in the chemical reduction of graphite oxide. Production of the solvent diethyl ether was the step that contributed the most for ultrasonication exfoliation, so solvent recovery is advised. For thermal exfoliation, microwave heating was the step that contributed the most to environmental impacts of graphene nanoplatelets. For chemical vapour deposition, the methane feedstock production step contributed the most, but methane recovery could reduce the energy use considerably. The environmental impacts of epitaxial graphene were dominated by electricity use for production of the silicon wafer substrate, which means that a ‘greener’ electricity mix can reduce impacts considerably. Overall, it is shown that graphene need not be an energy-intensive material compared to conventional materials used in society today.
Kandasamy G Moodley
Abstract
In view of the fact that corrosion costs large sums of money and touches countless facets of human activities, every possible effort needs to be made to find ways to stop it from starting. In this regard inhibition of corrosion has become a thriving commercial activity, worldwide. Much research has been ...
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In view of the fact that corrosion costs large sums of money and touches countless facets of human activities, every possible effort needs to be made to find ways to stop it from starting. In this regard inhibition of corrosion has become a thriving commercial activity, worldwide. Much research has been devoted to discovering newer strategies to inhibit corrosion with concomitant improvements in corrosion inhibition materials. This review will focus on the advances in materials and technologies for corrosion inhibition, with particular attention to the evolution of technologies and materials prior to the advent of coatings, the exploitation of ‘green methods’ which use anti-corrosion materials, which protect materials without fouling the environment; and the present and projected role of nanotechnology in inhibition of corrosion. This review brings together the collected wisdom of several disciplines. The latter addressed and/or are continuing to address the need for cost-effective materials to protect strategic metals used in the domestic and industrial sectors of most countries. The scope for improving the quality of materials, required for shielding these metals from the ravages of degrading agents, present in the environments of most cities, is lucidly articulated.
Sandip Maiti; Ranadip Bera;Bhanu B. Khatua; Sumanta K. Karan; Amit K. Das
Abstract
Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared ...
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Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared through simple and cost-effective method via in-situ polymerization of aniline in presence of CNH and TiO2 nanoparticles. Thus, as prepared active electrode material provides high specific capacitance value of 1068 F/g at current density of 3 A/g. The existence TiO2 nanoparticle in the ternary hybrid leads to enhancement of capacitance value through synergistic effect compared to the pure components (e.g., PANI and CNH are 335 F/g and 240 F/g, respectively at same current density). As morphological analysis says, TiO2 nanoparticles are observed to be coated by CNH nanofiller and PANI fiber in the hybrid, which plays a key role to enhance the capacitance value of hybrid making it highly promising electrode material for energy storage in the next-generation power supply.
Antonios Kelarakis
Abstract
In view of the continuous decline in fossil fuel reserves, at a time when energy demands are steadily increasing, a diverse range of emerging nanotechnologies promise to secure modern solutions to the prehistoric energy problem. Each one of those distinct approaches capitalizes on different principles, ...
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In view of the continuous decline in fossil fuel reserves, at a time when energy demands are steadily increasing, a diverse range of emerging nanotechnologies promise to secure modern solutions to the prehistoric energy problem. Each one of those distinct approaches capitalizes on different principles, concepts and methodologies to address different application requirements, but their common objective is to open a window to a sustainable energy future. Consequently, they all deserve substantial (though not necessarily equal) consideration from the scientific and engineering community. In this review we present bottom-up strategies that show great promise for the development of a new generation of advanced materials for energy applications without compromising the public safety or the environment.
Prashant K. Sharma; Ranu K. Dutta; Avinash C. Pandey
Abstract
Multifunctional magnetic nanoparticles have emerged as one of the important futuristic material for variety of applications starting from data storage, security/sensors to biomedical applications. The application of multifunctional magnetic nanoparticles in biological organisms has fashioned noteworthy ...
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Multifunctional magnetic nanoparticles have emerged as one of the important futuristic material for variety of applications starting from data storage, security/sensors to biomedical applications. The application of multifunctional magnetic nanoparticles in biological organisms has fashioned noteworthy advances in research, diagnosis and therapy of various diseases. The multifunctional magnetic nanoparticles, capable of theragnosis, drug delivery and monitoring of therapeutic response, are expected to play a significant role in the emergence of the era of personalized medicine with much of research efforts devoted toward that goal. The present review recapitulates the development of state-of-the-art multifunctional magnetic nanoparticles and the foremost applications of these multifunctional magnetic nanoparticles in magnetic targeting, drug delivery, separation, and contrast agents in magnetic resonance imaging, hyperthermia and sensors. The biocompatibility requirements and functionalization approach for multifunctional magnetic nanoparticles used in these applications are also reviewed.
Narayanasamy Vilvamani; Sasanka Deka; Tarkeshwar Gupta
Abstract
Designing anisotropic nano- and micro-structures are imperative in many technology oriented fields. Here we have reported a self templating method, where flower like microstructure of silver particles were used as template to generate several anisotropic structures such as rectangular cum dumbbell, cubes, ...
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Designing anisotropic nano- and micro-structures are imperative in many technology oriented fields. Here we have reported a self templating method, where flower like microstructure of silver particles were used as template to generate several anisotropic structures such as rectangular cum dumbbell, cubes, hexagonal whiskers, and rectangular bars etc. under controlled catalytic activity of Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ respectively. The initial flower like microstructure (template) of silver particles have been prepared from silver salt using disodium salt of 4,4’-dicarboxy-2,2’-bipyridyl(Na2dcbpy) as the reducing as well as capping agent. Then this architecture was used as the initial template to generate several anisotropic structures. The straightforward anisotropic microstructure preparation procedure does not require any other external template, which avoids the subsequent complicated workup. The nucleation processes and optical properties were studied using optical absorption spectroscopy. The anisotropic structure of the as-synthesized Ag particles and the formations of various shaped microstructures have been confirmed by Scanning Electron Microscopy (SEM). A possible mechanism has been proposed explaining the role of dcbpy in the growth of silver particles and the transition metal ion induced anisotropic structures.
Ivo Safarik; Kristyna Pospiskova; Eva Baldikova; Mirka Safarikova
Abstract
Diamagnetic biological materials of various origins (e.g., prokaryotic and eukaryotic microbial cells, lignocellulosic materials, food wastes, soluble and insoluble biopolymers etc.) can be magnetically modified in order to obtain smart biomaterials exhibiting an appropriate response to external magnetic ...
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Diamagnetic biological materials of various origins (e.g., prokaryotic and eukaryotic microbial cells, lignocellulosic materials, food wastes, soluble and insoluble biopolymers etc.) can be magnetically modified in order to obtain smart biomaterials exhibiting an appropriate response to external magnetic field. Magnetic modification of originally nonmagnetic biological materials is usually based on the attachment of magnetic iron oxides nano- and microparticles on the surface or within the pores of the treated material, or by their entrapment in the gel structure. Magnetic modification can be performed using different procedures, e.g., by magnetic fluid treatment, mechanochemical synthesis and by direct or indirect microwave assisted synthesis. This short review will summarize magnetic modification procedures developed by the authors and applications of advanced magnetically modified biomaterials as adsorbents of both organic and inorganic xenobiotics and radionuclides, affinity adsorbents for isolation of target biomolecules, carriers for various affinity ligands, biologically active compounds and cells or whole-cell biocatalysts. The potential of magnetically responsive biomaterials will increase in the near future.
Z. El Malki; M. Haddad;M. Bouachrine; M. Hamidi; J-P Lere-Porte; F. Serein-Spirau; L. Bejjit
Abstract
In this work the geometrical and electronic properties of (Carbazole-3.4-Ethylenedioxythiophene) (Cbz-Edot) based alternating donor-acceptor conjugated oligomers were studied by the density functional theory (DFT) at the B3LYP level with 6-31G(d) basis set. The acceptors investigated include thiazole ...
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In this work the geometrical and electronic properties of (Carbazole-3.4-Ethylenedioxythiophene) (Cbz-Edot) based alternating donor-acceptor conjugated oligomers were studied by the density functional theory (DFT) at the B3LYP level with 6-31G(d) basis set. The acceptors investigated include thiazole (Z), thiadiazole (D), thienopyrazine (TP), thienothiadiazole (TD), benzothiadiazole (BT) and thiadiazolothienopyrazine (TPD). A low band gap will be expected in polymers containing donor-acceptor (D-A) repeating units. In order to predict the band gaps for guiding the synthesis of novel materials with low band gaps, we apply quantum-chemical techniques to calculate the band gaps in several oligomers. The results have been compared with those of thiophene and 3,4-ethylenedioxythiophene polymers with donor-acceptor fragment. The lowest excitation energies (Eex) and the maximal absorption wavelength (λabs) are studied using the time dependent density functional theory (TD-DFT), method. The electronic transitions of the absorption spectrum derived by TD-DFT method give useful structural and electronic information for designing novel conducting organic polymer materials. The theoretical results suggest that both the acceptor strength and the stable geometry contribute significantly to the electronic properties of alternating donor-acceptor conjugated copolymers.
Shilpi Chaudhary; Ashley R. Head; Joachim Schnadt
Abstract
We have studied the adsorption of two silane compounds, (3-mercaptopropyl) trimethoxysilane (MPTMS) and n-propyltriethoxysilane (PTES), on a rutile TiO2(110) surface using angle dependent X-ray photoelectron spectroscopy. The observation of the S 2p line, in the case of MPTMS, and the C 1s line for both ...
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We have studied the adsorption of two silane compounds, (3-mercaptopropyl) trimethoxysilane (MPTMS) and n-propyltriethoxysilane (PTES), on a rutile TiO2(110) surface using angle dependent X-ray photoelectron spectroscopy. The observation of the S 2p line, in the case of MPTMS, and the C 1s line for both MPTMS and PTES confirms the adsorption of the molecules. For a dose of 122 Langmuirs of MPTMS we find room temperature coverage of 0.55 monolayers, while for a 60 Langmuir dose of PTES the coverage is found to be 0.89 monolayers. Thus, MPTMS has a considerably lower sticking coefficient on the rutile TiO2(110) surface than PTES. Both PTES and MPTES are found to bind dissociatively to the surface. An analysis of angle dependent data further suggests that for MPTMS the thiol group and thus alkyl chain points away from the surface, while for a 0.5 monolayer coverage of PTES the alkyl chain is oriented towards the surface. A higher coverage, ~1 monolayer, the behavior seems to be reversed for at least a fraction of all molecules. Temperature programmed XPS measurements suggest that the oxy groups of both molecules desorb from the surface at 550 K, which is in accordance with literature. The present study thus provides information on how these silane coupling agents bind to titanium oxide and what their molecular orientation is on the surface.
Burak Caglar; Justin Richards; Peter Fischer; Jens Tuebke
Abstract
In this study polypropylene (PP) based conductive composites and metal doped diamond like carbon (DLC) coated metallic substrates are studied as alternative bipolar materials for all-vanadium redox flow battery (VRFB). Graphite and carbon nanotube (CNT) filled PP based bipolar plates were produced via ...
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In this study polypropylene (PP) based conductive composites and metal doped diamond like carbon (DLC) coated metallic substrates are studied as alternative bipolar materials for all-vanadium redox flow battery (VRFB). Graphite and carbon nanotube (CNT) filled PP based bipolar plates were produced via twin-screw co-rotating extruder and injection molding. Addition of 3 wt. % CNTs into highly filled graphite-PP matrix increased in-plane and through-plane electrical conductivities from 10 S/cm to 50 S/cm and from 2 S/cm to 10 S/cm respectively. PP composites with 78 wt. % graphite and 2 wt. % CNT filling ratio showed flexural strength value of 48,01 MPa. Produced bipolar plates were examined with galvanostatic charge-discharge test in a single-cell VRFB. Energy efficiency of 85,43 % at 25 mA/cm2 and discharge power density of 78,48 mW/cm 2 at 75 mA/cm 2 were achieved and those values were found to be comparable with commercial bipolar plates. Titanium, vanadium, chromoium and tungsten doped diamond-like coating (DLC) films were coated on metallic substrates (e.g. stainless steel 1.4301 and titanium alloy 3.7165) by a physical vapor deposition. The metallic dopant is necessary to achieve high conductivities in the order of ~100 S/cm. The values range from 0.5 to 35 S/cm for in-plane and from 10 to 110 S/cm for through-plane. The hydrogen evolution reaction (HER) and the anodic corrosions stability in 2 molar sulfuric acid constituted the main focus area for our investigations on metallic bipolar plates. An interesting material for coated metallic bipolar plate is the 10 µm Ti-DLC on 1.4301 which exhibits the highest hydrogen evolution overpotential of all investigated materials (710 mV µA/cm²). It also showed improved corrosion stability for anodic potentials.
Attilio Marino; Gianni Ciofani
Abstract
In this article, we introduce the innovative nanotechnological approach of remote electric stimulation mediated by ultrasound-sensitive piezoelectric nanoparticles, especially focusing on its exploitation in the nanomedicine field for the “wireless” anticancer electric treatment. The nanoparticle ...
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In this article, we introduce the innovative nanotechnological approach of remote electric stimulation mediated by ultrasound-sensitive piezoelectric nanoparticles, especially focusing on its exploitation in the nanomedicine field for the “wireless” anticancer electric treatment. The nanoparticle functionalization with specific ligands allows the targeting, imaging, and ultimately the treatment of cancer cells. Piezoelectric stimulation can be performed in remote modality with ultrasound waves by virtue of the direct piezoelectric effect. Chronic piezo-stimulation is able to remarkably decrease cancer cell growth by inducing the cell cycle arrest in G0/G1phase and by affecting the cytoskeleton organization during cell division. The reported results indicate an impressive potential impact of this nanotechnological approach, that will be further tested in future works in synergic combination with chemotherapy treatment.
Peter A. Lieberzeit; Sadia Bajwa; Ghulam Mustafa; Thipvaree Wangchareansak; Franz L. Dickert
Abstract
Materials science increasingly focuses on generating “smart”, i.e. highly functional, advanced matrices. Selective recognition can be implemented into man-made polymers by template-assisted synthesis. The method covers a surprising size range: it is possible to generate sensitivity and selectivity ...
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Materials science increasingly focuses on generating “smart”, i.e. highly functional, advanced matrices. Selective recognition can be implemented into man-made polymers by template-assisted synthesis. The method covers a surprising size range: it is possible to generate sensitivity and selectivity towards bivalent metal cations, such as Cu 2+ , in polyacrylate matrices. Despite the template being substantially smaller in size than the monomers, recognition can be achieved. Furthermore, acrylates can be templated with much larger species, such as influenza viruses. This leads to a nanostructured polymer surface that selectively re-binds the respective virion. Additional enhancement of sensitivity can be achieved by composite materials. Silver sulphide nanoparticles for instance show very appreciable affinity towards butanol vapors. When blending into butanol-imprinted polyurethane, the material incorporates three times more of the alcohol.
Elguja Kutelia; David Gventsadze; Olga Tsurtsumia; Leri Rukhadze; Nikoloz Jalabadze; Tengiz Kukava; Teimuraz Dzigrashvili
Abstract
The present work is dealing with the study of a nano-compositional material which was obtained on the basis of PTFE with 2.5÷10wt% of core-shell type Fe-doped carbon nano-tubes and carbon nano-particles as fillers. The PTFE samples without the fillers were prepared too. Weight wear, friction coefficient ...
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The present work is dealing with the study of a nano-compositional material which was obtained on the basis of PTFE with 2.5÷10wt% of core-shell type Fe-doped carbon nano-tubes and carbon nano-particles as fillers. The PTFE samples without the fillers were prepared too. Weight wear, friction coefficient and temperature were measured after passing some velocity steps, and afterwards the linear wear was calculated. The obtained results have shown that the incorporation of about 2,5÷5wt% of Fe-doped CNTs into PTFE matrix drastically improves the antifrictional properties in comparison to the unfilled PTFE. Namely, the wear resistance of these nanocompositions increased by the factor of 500-150 in the range of friction velocities 0.25÷1.25 m/sec. Increase of the filler portion up to 10wt% transforms the obtained nanocomposite from antifrictional to friction material with the enhanced coefficient of friction up to 0.32, but with the unexpectedly ultra-low wear. SEM-EDX analyses of the worn surfaces of the tested nanocomposites and the cast iron samples after working as a tribological pair, revealed some favorable effects of the Fe-doped CNTs filler on the formation mechanism of a transfer film and its role in promoting very low wear of the obtained new nanocomposites.
Prashant K Sarswat; Madhusudan Jagannathan
Abstract
Elastic properties of nanostructures are crucial for the adequate design and long term use of nano/micro-electro-mechanical system (NEMS/MEMS) as well as their utility in nanoindentation. Carbon nanostructures were fabricated by focused ion beam (FIB) assisted deposition and milling using Naphthalene ...
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Elastic properties of nanostructures are crucial for the adequate design and long term use of nano/micro-electro-mechanical system (NEMS/MEMS) as well as their utility in nanoindentation. Carbon nanostructures were fabricated by focused ion beam (FIB) assisted deposition and milling using Naphthalene (C10H8) as a precursor gas. Cantilevers of size 3-10 µm were fabricated and their elastic properties were monitored. An end point load was applied by successive deposition of Pt or carbon in a form of vertical column. Euler–Bernoulli beam theory was applied to examine the mechanical properties of the cantilever. It has been observed that expected deflection of the carbon nano-cantilever is significantly different compared to most of the reported micro or nano-sized carbon or diamond structures. Initial investigation of such a discrepancy suggests that Ga implantation and presence of core-shell type structure are the main causes of altered mechanical properties.
David L. Fuks; Arnold E. Kiv
Abstract
Anchor Practically applicable approach for the fabrication of ABO3 perovskites with high rates of ionic transport is developed. The ionic transport in perovskites with transition metals at B – site is considered in terms of the theory of coordination compounds. It is shown that the structure of ...
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Anchor Practically applicable approach for the fabrication of ABO3 perovskites with high rates of ionic transport is developed. The ionic transport in perovskites with transition metals at B – site is considered in terms of the theory of coordination compounds. It is shown that the structure of these materials is sensitive to the values of the effective charge of the ions of transition metals (Z * ) and to the electronegativity (χ) of the surrounding cations. The magnitudes of Z * and χ can be varied by choosing the appropriate elements at sites A and B to induce a distortion of the short range order. This leads to reduction of potential barriers for formation and migration of structural defects including oxygen vacancies. In typical perovskites a correlation between the rates of the ionic transport and the estimated values of Z * and χ is found.
Naoki Toyama; Haruki Inoue; Shinobu Ohki; Masataka Tansho; Tadashi Shimizu; Tetsuo Umegaki; Yoshiyuki Kojima
Abstract
In this work, we investigate influence of amount of L(+)-arginine on morphology of hollow silica-alumina composite spheres and their activity for hydrolytic dehydrogenation of ammonia borane. Hollow silica-alumina composite spheres were prepared by polystyrene templates method. In this method, silica-alumina ...
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In this work, we investigate influence of amount of L(+)-arginine on morphology of hollow silica-alumina composite spheres and their activity for hydrolytic dehydrogenation of ammonia borane. Hollow silica-alumina composite spheres were prepared by polystyrene templates method. In this method, silica-alumina composite shell were coated on polystyrene particles via a sol-gel reaction using L(+)-arginine as promoter, and the polystyrene template particles were removed by calcination. From the result of transmission electron microscopy, shell thickness of the hollow spheres prepared amount of L(+)-arginine of 0.0581, 0.1163, 0.2325, and 0.4650 g were 10, 20, 26, and 30 nm, respectively. From the result of nitrogen sorption, average pore size of the hollow spheres prepared amount of L(+)-arginine of 0.0581, 0.1163, 0.2325, and 0.4650 g was 6.2, 4.2, 3.4, and 2.9 nm, respectively. These results indicate that pore size and shell thickness changed into adjusting amount of L(+)-arginine. Activity of the hollow spheres prepared using various amount of L(+)-arginine for hydrolytic dehydrogenation of ammonia borane were compared. The result indicates that amount of hydrogen evolution of all the hollow spheres was almost the same level. On the other hands, hydrogen evolution rate increase with decrease of amount of L(+)-arginine.
Sushilkumar A. Jadhav; Roberta Bongiovanni
Abstract
Several new techniques are invented in recent years to attach organic, bio-organic functionalities to the nanostructures such as the nanoparticles. This approach of adding surface reactivity to the particles enables to tune the properties and reactivity of the resulting hybrid monolayer protected nanoparticles. ...
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Several new techniques are invented in recent years to attach organic, bio-organic functionalities to the nanostructures such as the nanoparticles. This approach of adding surface reactivity to the particles enables to tune the properties and reactivity of the resulting hybrid monolayer protected nanoparticles. Magnetic iron oxide nanoparticles of various sizes are reported which bears different organic or polymeric groups. In the present note we have revised the important methods of synthesis of magnetite (Fe3O4) nanoparticles and highlighted the most common strategies for the functionalization of these nanoparticles with organic compounds from very recent literature. This short note will help the students and researchers to screen and choose methods for the synthesis and functionalization of magnetite nanoparticles.
Fatma Pinar Gokdemir; vecihe Ece Yuzbasioglu; Bahadir Keskin; Orhan Ozdemir; Kubilay Kutlu
Abstract
Through a modified sol gel route with titanium isopropoxide (TIP) and acetic acid, titanium dioxide (TiO2) thin films were deposited by dip coating. Employing acetic acid as modifier and without inclusion of water in hydrolysis leaded to control the degree of condensation-oligorimerization of the precursor ...
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Through a modified sol gel route with titanium isopropoxide (TIP) and acetic acid, titanium dioxide (TiO2) thin films were deposited by dip coating. Employing acetic acid as modifier and without inclusion of water in hydrolysis leaded to control the degree of condensation-oligorimerization of the precursor and formation of anatase phase only upon annealing. Direct allowed energy band gap 3.87 eV verified the anatase phase of the film. Impact of temperature on structural properties was deduced by FTIR and UV-Visible spectroscopies. Due to the reduction in band gap with increase in annealing temperature, injected Li + charge amount dropped in anatase compared to the amorphous (unannealed) films.
Leon Shaw; Maziar Ashuri
Abstract
Layered lithium nickel manganese cobalt oxides, Li(NixMnyCoz)O2 where x + y + z = 1 (NMCs), have been studied extensively due to their higher capacity, less toxicity and lower cost compared to LiCoO2. However, widespread market penetration of NMCs as cathodes for Li-ion batteries (LIBs) is impeded by ...
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Layered lithium nickel manganese cobalt oxides, Li(NixMnyCoz)O2 where x + y + z = 1 (NMCs), have been studied extensively due to their higher capacity, less toxicity and lower cost compared to LiCoO2. However, widespread market penetration of NMCs as cathodes for Li-ion batteries (LIBs) is impeded by their poor capacity retention and low rate capability. Coatings provide an effective solution to these problems. This article focuses on review of the recent advancements in coatings of NMCs from the mechanism viewpoint. This is the first time that coatings on NMCs are reviewed based on their functionalities and mechanisms through which the electrochemical properties and performance of NMCs have been improved. To provide a comprehensive understanding of the functions and mechanisms offered by coatings, the following functions and mechanisms are reviewed individually: (i) scavenging HF in the electrolyte, (ii) scavenging water molecules in the electrolyte and thus suppressing HF propagation during charge/discharge cycles, (iii) serving as a buffer layer to minimize HF attack on NMCs and suppress side reactions between NMCs and the electrolyte, (iv) hindering phase transitions and impeding loss of lattice oxygen, (v) preventing microcracks in NMC particles to keep participation of most NMC material in lithiation/de-lithiation, and (vi) enhancing the rate capability of NMC cathodes. Finally, the personal perspectives on outlook are offered with an aim to stimulate further discussion and ideas on the rational design of coatings for durable and high-performance NMC cathodes for the next generation LIBs in the near future.
Preetam Singh; K. M. K. Srivatsa;Sourav Das
Abstract
Single oriented nanocrystalline CeO2 thin films have been deposited over Si (100) substrate by RF magnetron sputtering in the temperature range 600-700 o C, using CeO2 target. X-ray diffraction pattern for the as deposited CeO2 film at 700 o C shows the dominant (111) orientation with corresponding FWHM ...
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Single oriented nanocrystalline CeO2 thin films have been deposited over Si (100) substrate by RF magnetron sputtering in the temperature range 600-700 o C, using CeO2 target. X-ray diffraction pattern for the as deposited CeO2 film at 700 o C shows the dominant (111) orientation with corresponding FWHM value of 0.378 o and the crystallite size 21.50 nm. The refractive index and the optical band gap both were found to increase from 2.35 to 2.66 and 3.25 to 3.43 eV, respectively with increasing substrate temperature. Atomic force microscopy results reveal highly smooth surface of the deposited films with surface roughness below 1.15 nm for the entire range of deposition temperatures. Further, the contact angle measurements on the as deposited CeO2 films showed variation from 122.36 to 81.67 o with respect to the substrate temperature, transforming the wetting property from hydrophobic to hydrophilic in nature. These results indicate the possibility of producing CeO2 films with varying properties for various device applications simply by controlling the substrate temperature.
Maria C. Basso; Xinjun Li; Vanessa Fierro; Antonio Pizzi; Samuele Giovando; Alain Celzard
Abstract
New, green and cheap rigid foams presenting outstanding performances for thermal insulation are described. Such ultra-lightweight cellular materials are mainly based on renewable chemicals: tannin and furfuryl alcohol, are very easy to produce and have thermal conductivity as low as 38 mW/m/K. Compared ...
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New, green and cheap rigid foams presenting outstanding performances for thermal insulation are described. Such ultra-lightweight cellular materials are mainly based on renewable chemicals: tannin and furfuryl alcohol, are very easy to produce and have thermal conductivity as low as 38 mW/m/K. Compared to previously reported tannin-based foams, these new materials are much “greener” and present improved resistance to compression and to water. Especially the formaldehyde, formerly used as cross-linking agent of tannins but known as a volatile and harmful chemical, could be successfully removed from the formulation. The as-obtained, 2nd generation, tannin-based foams are totally stable and have an expected interest for thermal insulation of buildings.
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