Direct Observation of Magnetocrystalline Anisotropy Tuning Magnetization Configurations in Uniaxial Magnetic Nanomaterials

KAUST Repository

Zhu, Shimeng

2018-03-20

Discovering the effect of magnetic anisotropy on the magnetization configurations of magnetic nanomaterials is essential and significant for not only enriching the fundamental knowledge of magnetics but also facilitating the designs of desired magnetic nanostructures for diverse technological applications, such as data storage devices, spintronic devices, and magnetic nanosensors. Herein, we present a direct observation of magnetocrystalline anisotropy tuning magnetization configurations in uniaxial magnetic nanomaterials with hexagonal structure by means of three modeled samples. The magnetic configuration in polycrystalline BaFe12O19 nanoslice is a curling structure, revealing that the effect of magnetocrystalline anisotropy in uniaxial magnetic nanomaterials can be broken by forming an amorphous structure or polycrystalline structure with tiny grains. Both single crystalline BaFe12O19 nanoslice and individual particles of single-particle-chain BaFe12O19 nanowire appear in a single domain state, revealing a dominant role of magnetocrystalline anisotropy in the magnetization configuration of uniaxial magnetic nanomaterials. These observations are further verified by micromagnetic computational simulations.

Emerging Carbon and Post-Carbon Nanomaterial Inks for Printed Electronics.

Science.gov (United States)

Secor, Ethan B; Hersam, Mark C

2015-02-19

Carbon and post-carbon nanomaterials present desirable electrical, optical, chemical, and mechanical attributes for printed electronics, offering low-cost, large-area functionality on flexible substrates. In this Perspective, recent developments in carbon nanomaterial inks are highlighted. Monodisperse semiconducting single-walled carbon nanotubes compatible with inkjet and aerosol jet printing are ideal channels for thin-film transistors, while inkjet, gravure, and screen-printable graphene-based inks are better-suited for electrodes and interconnects. Despite the high performance achieved in prototype devices, additional effort is required to address materials integration issues encountered in more complex systems. In this regard, post-carbon nanomaterial inks (e.g., electrically insulating boron nitride and optically active transition-metal dichalcogenides) present promising opportunities. Finally, emerging work to extend these nanomaterial inks to three-dimensional printing provides a path toward nonplanar devices. Overall, the superlative properties of these materials, coupled with versatile assembly by printing techniques, offer a powerful platform for next-generation printed electronics.

Carbon nanomaterial based electrochemical sensors for biogenic amines

International Nuclear Information System (INIS)

Yang, Xiao; He, Xiulan; Li, Fangping; Fei, Junjie; Feng, Bo; Ding, Yonglan

2013-01-01

This review describes recent advances in the use of carbon nanomaterials for electroanalytical detection of biogenic amines (BAs). It starts with a short introduction into carbon nanomaterials such as carbon nanotubes, graphene, nanodiamonds, carbon nanofibers, fullerenes, and their composites. Next, electrochemical sensing schemes are discussed for various BAs including dopamine, serotonin, epinephrine, norepinephrine, tyramine, histamine and putrescine. Examples are then given for methods for simultaneous detection of various BAs. Finally, we discuss the current and future challenges of carbon nanomaterial-based electrochemical sensors for BAs. The review contains 175 references. (author)

Performance Enhancement of Carbon Nanomaterials for Supercapacitors

Directory of Open Access Journals (Sweden)

Amin M. Saleem

2016-01-01

Full Text Available Carbon nanomaterials such as carbon nanotubes, carbon nanofibers, and graphene are exploited extensively due to their unique electrical, mechanical, and thermal properties and recently investigated for energy storage application (supercapacitor due to additional high specific surface area and chemical inertness properties. The supercapacitor is an energy storage device which, in addition to long cycle life (one million, can give energy density higher than parallel plate capacitor and power density higher than battery. In this paper, carbon nanomaterials and their composites are reviewed for prospective use as electrodes for supercapacitor. Moreover, different physical and chemical treatments on these nanomaterials which can potentially enhance the capacitance are also reviewed.

Biological interactions of carbon-based nanomaterials: From coronation to degradation.

Science.gov (United States)

Bhattacharya, Kunal; Mukherjee, Sourav P; Gallud, Audrey; Burkert, Seth C; Bistarelli, Silvia; Bellucci, Stefano; Bottini, Massimo; Star, Alexander; Fadeel, Bengt

2016-02-01

Carbon-based nanomaterials including carbon nanotubes, graphene oxide, fullerenes and nanodiamonds are potential candidates for various applications in medicine such as drug delivery and imaging. However, the successful translation of nanomaterials for biomedical applications is predicated on a detailed understanding of the biological interactions of these materials. Indeed, the potential impact of the so-called bio-corona of proteins, lipids, and other biomolecules on the fate of nanomaterials in the body should not be ignored. Enzymatic degradation of carbon-based nanomaterials by immune-competent cells serves as a special case of bio-corona interactions with important implications for the medical use of such nanomaterials. In the present review, we highlight emerging biomedical applications of carbon-based nanomaterials. We also discuss recent studies on nanomaterial 'coronation' and how this impacts on biodistribution and targeting along with studies on the enzymatic degradation of carbon-based nanomaterials, and the role of surface modification of nanomaterials for these biological interactions. Advances in technology have produced many carbon-based nanomaterials. These are increasingly being investigated for the use in diagnostics and therapeutics. Nonetheless, there remains a knowledge gap in terms of the understanding of the biological interactions of these materials. In this paper, the authors provided a comprehensive review on the recent biomedical applications and the interactions of various carbon-based nanomaterials. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Capillary electrophoresis and nanomaterials - Part I: Capillary electrophoresis of nanomaterials.

Science.gov (United States)

Adam, Vojtech; Vaculovicova, Marketa

2017-10-01

Nanomaterials are in analytical science used for a broad range of purposes, covering the area of sample pretreatment as well as separation, detection, and identification of target molecules. This part of the review covers capillary electrophoresis (CE) of nanomaterials and focuses on the application of CE as a method for characterization used during nanomaterial synthesis and modification as well as the monitoring of their properties and interactions with other molecules. The heterogeneity of the nanomaterial family is extremely large. Depending on different definitions of the term Nanomaterial/Nanoparticle, the group may cover metal and polymeric nanoparticles, carbon nanomaterials, liposomes and even dendrimers. Moreover, these nanomaterials are usually subjected to some kind of surface modification or functionalization, which broadens the diversity even more. Not only for purposes of verification of nanomaterial synthesis and batch-to-batch quality check, but also for determination the polydispersity and for functionality characterization on the nanoparticle surface, has CE offered very beneficial capabilities. Finally, the monitoring of interactions between nanomaterials and other (bio)molecules is easily performed by some kind of capillary electromigration technique. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon nanomaterials for gas adsorption

CERN Document Server

Terranova, Maria Letizia

2012-01-01

Research in adsorption of gases by carbon nanomaterials has experienced considerable growth in recent years, with increasing interest for practical applications. Many research groups are now producing or using such materials for gas adsorption, storage, purification, and sensing. This book provides a selected overview of some of the most interesting scientific results regarding the outstanding properties of carbon nanomaterials for gas adsorption and of interest both for basic research and technological applications. Topics receiving special attention in this book include storage of H, purific

Carbon Nanomaterials for Breast Cancer Treatment

Directory of Open Access Journals (Sweden)

M. L. Casais-Molina

2018-01-01

Full Text Available Currently, breast cancer is considered as a health problem worldwide. Furthermore, current treatments neither are capable of stopping its propagation and/or recurrence nor are specific for cancer cells. Therefore, side effects on healthy tissues and cells are common. An increase in the efficiency of treatments, along with a reduction in their toxicity, is desirable to improve the life quality of patients affected by breast cancer. Nanotechnology offers new alternatives for the design and synthesis of nanomaterials that can be used in the identification, diagnosis, and treatment of cancer and has now become a very promising tool for its use against this disease. Among the wide variety of nanomaterials, the scientific community is particularly interested in carbon nanomaterials (fullerenes, nanotubes, and graphene due to their physical properties, versatile chemical functionalization, and biocompatibility. Recent scientific evidence shows the potential uses of carbon nanomaterials as therapeutic agents, systems for selective and controlled drug release, and contrast agents for diagnosing and locating tumors. This generates new possibilities for the development of innovative systems to treat breast cancer and can be used to detect this disease at much earlier stages. Thus, applications of carbon nanomaterials in breast cancer treatment are discussed in this article.

Assembly of ordered carbon shells on semiconducting nanomaterials

Science.gov (United States)

Sutter, Eli Anguelova; Sutter, Peter Werner

2012-10-02

In some embodiments of the invention, encapsulated semiconducting nanomaterials are described. In certain embodiments the nanostructures described are semiconducting nanomaterials encapsulated with ordered carbon shells. In some aspects a method for producing encapsulated semiconducting nanomaterials is disclosed. In some embodiments applications of encapsulated semiconducting nanomaterials are described.

Introduction to nanoparticles, nanocomposites, nanomaterials an introduction for beginners

CERN Document Server

Vollath, Dieter

2013-01-01

Meeting the demand for a readily understandable introduction to nanomaterials and nanotechnology, this textbook specifically addresses the needs of students - and engineers - who need to get the gist of nanoscale phenomena in materials without having to delve too deeply into the physical and chemical details. The book begins with an overview of the consequences of small particle size, such as the growing importance of surface effects, and covers successful, field-tested synthesis techniques of nanomaterials. The largest part of the book is devoted to the particular magnetic, optical, electrical and mechanical properties of materials at the nanoscale, leading on to emerging and already commercialized applications, such as nanofluids in magnetic resonance imaging, high-performance nanocomposites and carbon nanotube-based electronics. Based on the author's experience in teaching nanomaterials courses and adapted, in style and level, for students with only limited background knowledge, the textbook includes fur...

Hydrogen Storage in Carbon Nano-materials

International Nuclear Information System (INIS)

David Eyler; Michel Junker; Emanuelle Breysse Carraboeuf; Laurent Allidieres; David Guichardot; Fabien Roy; Isabelle Verdier; Edward Mc Rae; Moulay Rachid Babaa; Gilles Flamant; David Luxembourg; Daniel Laplaze; Patrick Achard; Sandrine Berthon-Fabry; David Langohr; Laurent Fulcheri

2006-01-01

This paper presents the results of a French project related to hydrogen storage in carbon nano-materials. This 3 years project, co-funded by the ADEME (French Agency for the Environment and the Energy Management), aimed to assess the hydrogen storage capacity of carbon nano-materials. Four different carbon materials were synthesized and characterized in the frame of present project: - Carbon Nano-tubes; - Carbon Nano-fibres; - Carbon Aerogel; - Carbon Black. All materials tested in the frame of this project present a hydrogen uptake of less than 1 wt% (-20 C to 20 C). A state of the art of hydrogen storage systems has been done in order to determine the research trends and the maturity of the different technologies. The choice and design of hydrogen storage systems regarding fuel cell specifications has also been studied. (authors)

Carbon nanomaterials for advanced energy conversion and storage.

Science.gov (United States)

Dai, Liming; Chang, Dong Wook; Baek, Jong-Beom; Lu, Wen

2012-04-23

It is estimated that the world will need to double its energy supply by 2050. Nanotechnology has opened up new frontiers in materials science and engineering to meet this challenge by creating new materials, particularly carbon nanomaterials, for efficient energy conversion and storage. Comparing to conventional energy materials, carbon nanomaterials possess unique size-/surface-dependent (e.g., morphological, electrical, optical, and mechanical) properties useful for enhancing the energy-conversion and storage performances. During the past 25 years or so, therefore, considerable efforts have been made to utilize the unique properties of carbon nanomaterials, including fullerenes, carbon nanotubes, and graphene, as energy materials, and tremendous progress has been achieved in developing high-performance energy conversion (e.g., solar cells and fuel cells) and storage (e.g., supercapacitors and batteries) devices. This article reviews progress in the research and development of carbon nanomaterials during the past twenty years or so for advanced energy conversion and storage, along with some discussions on challenges and perspectives in this exciting field. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New advances in electrochemical biosensors for the detection of toxins: Nanomaterials, magnetic beads and microfluidics systems. A review

International Nuclear Information System (INIS)

Reverté, Laia; Prieto-Simón, Beatriz; Campàs, Mònica

2016-01-01

The use of nanotechnology in bioanalytical devices has special advantages in the detection of toxins of interest in food safety and environmental applications. The low levels to be detected and the small size of toxins justify the increasing number of publications dealing with electrochemical biosensors, due to their high sensitivity and design versatility. The incorporation of nanomaterials in their development has been exploited to further increase their sensitivity, providing simple and fast devices, with multiplexed capabilities. This paper gives an overview of the electrochemical biosensors that have incorporated carbon and metal nanomaterials in their configurations for the detection of toxins. Biosensing systems based on magnetic beads or integrated into microfluidics systems have also been considered because of their contribution to the development of compact analytical devices. The roles of these materials, the methods used for their incorporation in the biosensor configurations as well as the advantages they provide to the analyses are summarised. - Highlights: • Nanomaterials improve the performance of electrochemical biosensors. • Carbon nanomaterials can act as electrocatalysts or label supports in biosensors. • Metal nanomaterials can act as nanostructured supports or labels in biosensors. • Magnetic beads are exploited as immobilisation supports and/or label carriers.

New advances in electrochemical biosensors for the detection of toxins: Nanomaterials, magnetic beads and microfluidics systems. A review

Energy Technology Data Exchange (ETDEWEB)

Reverté, Laia [IRTA, Carretera Poble Nou km. 5.5, 43540 Sant Carles de la Ràpita, Tarragona (Spain); Prieto-Simón, Beatriz [ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, SA 5095 (Australia); Campàs, Mònica, E-mail: monica.campas@irta.cat [IRTA, Carretera Poble Nou km. 5.5, 43540 Sant Carles de la Ràpita, Tarragona (Spain)

2016-02-18

The use of nanotechnology in bioanalytical devices has special advantages in the detection of toxins of interest in food safety and environmental applications. The low levels to be detected and the small size of toxins justify the increasing number of publications dealing with electrochemical biosensors, due to their high sensitivity and design versatility. The incorporation of nanomaterials in their development has been exploited to further increase their sensitivity, providing simple and fast devices, with multiplexed capabilities. This paper gives an overview of the electrochemical biosensors that have incorporated carbon and metal nanomaterials in their configurations for the detection of toxins. Biosensing systems based on magnetic beads or integrated into microfluidics systems have also been considered because of their contribution to the development of compact analytical devices. The roles of these materials, the methods used for their incorporation in the biosensor configurations as well as the advantages they provide to the analyses are summarised. - Highlights: • Nanomaterials improve the performance of electrochemical biosensors. • Carbon nanomaterials can act as electrocatalysts or label supports in biosensors. • Metal nanomaterials can act as nanostructured supports or labels in biosensors. • Magnetic beads are exploited as immobilisation supports and/or label carriers.

In Situ Formation of Carbon Nanomaterials on Bulk Metallic Materials

Directory of Open Access Journals (Sweden)

J. Y. Xu

2014-01-01

Full Text Available Carbon nanomaterials were synthesized in situ on bulk 316L stainless steel, pure cobalt, and pure nickel by hybrid surface mechanical attrition treatment (SMAT. The microstructures of the treated samples and the resulted carbon nanomaterials were investigated by SEM and TEM characterizations. Different substrates resulted in different morphologies of products. The diameter of carbon nanomaterials is related to the size of the nanograins on the surface layer of substrates. The possible growth mechanism was discussed. Effects of the main parameters of the synthesis, including the carbon source and gas reactant composition, hydrogen, and the reaction temperature, were studied. Using hybrid SMAT is proved to be an effective way to synthesize carbon nanomaterials in situ on surfaces of metallic materials.

FROM ZERO-DIMENSIONAL TO 2-DIMENSIONAL CARBON NANOMATERIALS - part I: TYPES OF CNs

Directory of Open Access Journals (Sweden)

Cătălin IANCU

2012-05-01

Full Text Available In recent years, many theoretical and experimental studies have been carried out to develop one of the most interesting aspects of the science and nanotechnology which is called carbon-related nanomaterials. In this review paper are presented some of the most important developments in the synthesis, properties, and applications of low-dimensional carbon nanomaterials. The synthesis techniques are used to produce specific kinds of low-dimensional carbon nanomaterials such as zero-dimensional CNs (including fullerene, carbon-encapsulated metal nanoparticles, nanodiamond, and onion-like carbons, one-dimensional carbon nanomaterials (including carbon nanofibers and carbon nanotubes, and two-dimensional carbon nanomaterials (including graphene and carbon nanowalls.

Preparation and thermal properties characterization of carbonate salt/carbon nanomaterial composite phase change material

International Nuclear Information System (INIS)

Tao, Y.B.; Lin, C.H.; He, Y.L.

2015-01-01

Highlights: • Nanocomposite phase change materials were prepared and characterized. • Larger specific surface area is more efficient to enhance specific heat. • Columnar structure is more efficient to enhance thermal conductivity. • Thermal conductivity enhancement is the key. • Single walled carbon nanotube is the optimal nanomaterial additive. - Abstract: To enhance the performance of high temperature salt phase change material, four kinds of carbon nanomaterials with different microstructures were mixed into binary carbonate eutectic salts to prepare carbonate salt/nanomaterial composite phase change material. The microstructures of the nanomaterial and composite phase change material were characterized by scanning electron microscope. The thermal properties such as melting point, melting enthalpy, specific heat, thermal conductivity and total thermal energy storage capacity were characterized. The results show that the nanomaterial microstructure has great effects on composite phase change material thermal properties. The sheet structure Graphene is the best additive to enhance specific heat, which could be enhanced up to 18.57%. The single walled carbon nanotube with columnar structure is the best additive to enhance thermal conductivity, which could be enhanced up to 56.98%. Melting point increases but melting enthalpy decreases with nanomaterial specific surface area increase. Although the additives decrease the melting enthalpy of composite phase change material, they also enhance the specific heat. As a combined result, the additives have little effects on thermal energy storage capacity. So, for phase change material performance enhancement, more emphasis should be placed on thermal conductivity enhancement and single walled carbon nanotube is the optimal nanomaterial additive

Carbon Nanomaterials in Biological Studies and Biomedicine.

Science.gov (United States)

Teradal, Nagappa L; Jelinek, Raz

2017-09-01

The "carbon nano-world" has made over the past few decades huge contributions in diverse scientific disciplines and technological advances. While dramatic advances have been widely publicized in using carbon nanomaterials such as fullerenes, carbon nanotubes, and graphene in materials sciences, nano-electronics, and photonics, their contributions to biology and biomedicine have been noteworthy as well. This Review focuses on the use of carbon nanotubes (CNTs), graphene, and carbon quantum dots [encompassing graphene quantum dots (GQDs) and carbon dots (C-dots)] in biologically oriented materials and applications. Examples of these remarkable nanomaterials in bio-sensing, cell- and tissue-imaging, regenerative medicine, and other applications are presented and discussed, emphasizing the significance of their unique properties and their future potential. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrogen storage properties of carbon nanomaterials and carbon containing metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Maehlen, Jan Petter

2003-07-01

The topic of this thesis is structural investigations of carbon containing materials in respect to their hydrogen storage properties. This work was initially triggered by reports of extremely high hydrogen storage capacities of specific carbon nanostructures. It was decided to try to verify and understand the mechanisms in play in case of the existence of such high hydrogen densities in carbon. Two different routes towards the goal were employed; by studying selected hydrides with carbon as one of its constituents (mainly employing powder diffraction techniques in combination with hydrogen absorption and desorption measurements) and by carefully conducting hydrogen sorption experiments on what was believed to be the most ''promising'' carbon nanomaterial sample. In the latter case, a lot of effort was attributed to characterisations of different carbon nanomaterial containing samples with the aid of electron microscopy. Three different carbon-containing metal hydride systems, Y2C-H, YCoC-H and Y5SiC0.2-H, were examined. A relation between hydrogen occupation and the local arrangement of metal and carbon atoms surrounding the hydrogen sites was established. Several characteristic features of the compounds were noted in addition to solving the structure of the former unknown deuterideY5Si3C0.2D2.0 by the use of direct methods. Several carbon-nanomaterial containing samples were studied by means of transmission electron microscopy and powder diffraction, thus gaining knowledge concerning the structural aspects of nanomaterials. Based on these investigations, a specific sample containing a large amount of open-ended single-wall carbon nanotubes was chosen for subsequent hydrogen storage experiments. The latter experiments revealed moderate hydrogen storage capacities of the nanotubes not exceeding the values obtained for more conventional forms of carbon. These two different routes in investigating the hydrogen storage properties of carbon and carbon containing alloys

Hydrogen storage properties of carbon nanomaterials and carbon containing metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Maehlen, Jan Petter

2003-07-01

The topic of this thesis is structural investigations of carbon containing materials in respect to their hydrogen storage properties. This work was initially triggered by reports of extremely high hydrogen storage capacities of specific carbon nanostructures. It was decided to try to verify and understand the mechanisms in play in case of the existence of such high hydrogen densities in carbon. Two different routes towards the goal were employed; by studying selected hydrides with carbon as one of its constituents (mainly employing powder diffraction techniques in combination with hydrogen absorption and desorption measurements) and by carefully conducting hydrogen sorption experiments on what was believed to be the most ''promising'' carbon nanomaterial sample. In the latter case, a lot of effort was attributed to characterisations of different carbon nanomaterial containing samples with the aid of electron microscopy. Three different carbon-containing metal hydride systems, Y2C-H, YCoC-H and Y5SiC0.2-H, were examined. A relation between hydrogen occupation and the local arrangement of metal and carbon atoms surrounding the hydrogen sites was established. Several characteristic features of the compounds were noted in addition to solving the structure of the former unknown deuterideY5Si3C0.2D2.0 by the use of direct methods. Several carbon-nanomaterial containing samples were studied by means of transmission electron microscopy and powder diffraction, thus gaining knowledge concerning the structural aspects of nanomaterials. Based on these investigations, a specific sample containing a large amount of open-ended single-wall carbon nanotubes was chosen for subsequent hydrogen storage experiments. The latter experiments revealed moderate hydrogen storage capacities of the nanotubes not exceeding the values obtained for more conventional forms of carbon. These two different routes in investigating the hydrogen storage properties of carbon and

Carbon and oxide nanostructures. Synthesis, characterisation and applications

Energy Technology Data Exchange (ETDEWEB)

Yahya, Noorhana [Universiti Teknologi PETRONAS, Tronoh, Perak (Malaysia). Dept. of Fundamental and Applied Sciences

2010-07-01

This volume covers all aspects of carbon and oxide based nanostructured materials. The topics include synthesis, characterization and application of carbon-based namely carbon nanotubes, carbon nanofibres, fullerenes, carbon filled composites etc. In addition, metal oxides namely, ZnO, TiO2, Fe2O3, ferrites, garnets etc., for various applications like sensors, solar cells, transformers, antennas, catalysts, batteries, lubricants, are presented. The book also includes the modeling of oxide and carbon based nanomaterials. The book covers the topics: - Synthesis, characterization and application of carbon nanotubes, carbon nanofibres, fullerenes - Synthesis, characterization and application of oxide based nanomaterials. - Nanostructured magnetic and electric materials and their applications. - Nanostructured materials for petro-chemical industry. - Oxide and carbon based thin films for electronics and sustainable energy. - Theory, calculations and modeling of nanostructured materials. (orig.)

Metal-filled carbon nanotubes as a novel class of photothermal nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Rossella, Francesco; Bellani, Vittorio [Dipartimento di Fisica ' ' A. Volta' ' and CNISM, Universita degli Studi di Pavia, Via Bassi 6, 27100 Pavia (Italy); Soldano, Caterina [Dipartimento di Chimica e Fisica, Universita degli Studi di Brescia, Via Valotti 9, 25121 Brescia (Italy); Tommasini, Matteo [Dipartimento di Chimica, Materiali e Ingegneria Chimica ' ' G. Natta' ' , Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

2012-05-08

Metal-filled carbon nanotubes represent a novel class of photothermal nanomaterials: when illuminated by visible light they exhibit a strong enhancement of the temperature at the metal sites, due to the enhanced plasmonic light absorption at the metal surface, which behaves as a heat radiator. Potential applications include nanomedicine, heat-assisted magnetic recording, and light-activated thermal gradient-driven devices. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Carbon-based nanomaterials: multifunctional materials for biomedical engineering.

Science.gov (United States)

Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R; Khademhosseini, Ali

2013-04-23

Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), and extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications.

Synthesis of carbon nanomaterials from different pyrolysis techniques: a review

Science.gov (United States)

Umer Zahid, Muhammad; Pervaiz, Erum; Hussain, Arshad; Shahzad, Muhammad Imran; Niazi, Muhammad Bilal Khan

2018-05-01

In the current age, the significance of carbon-based nanomaterials for many applications has made the efforts for the facile synthesis methods from abundantly available wastes in a cost-effective way. Pyrolysis in a broad spectrum is commonly employed for the synthesis of carbon nanostructures by thermally treating the organic waste. The mechanism of growth of the nanoparticles determines the functional distribution of nanoparticles based on the growing size, medium, and physio-chemical properties. Carbon nanomaterial’s growth is a complicated process which is profoundly influenced by temperature, catalyst, and type of precursor. Nowadays, significant progress has been made in improving nanomaterial’s growth techniques, opening new paths for commercial production of carbon-based nanomaterials. The most promising are the methods involving hydrocarbon-rich organic waste as the feed source. In this review, synthesis of carbon-based nanomaterials, specifically carbon nanotubes (CNTs), Carbon nanofibers (CNFs) and Graphene (G) are discussed by different pyrolysis techniques. Furthermore, the review explores recent advancements made in the context of pyrolysis.

FROM ZERO-DIMENSIONAL TO 2-DIMENSIONAL CARBON NANOMATERIALS - part II: GRAPHENE

Directory of Open Access Journals (Sweden)

Cătălin IANCU

2012-05-01

Full Text Available As was presented in the first part of this review paper, lately, many theoretical and experimental studies have been carried out to develop one of the most interesting aspects of the science and nanotechnology which is called carbon-related nanomaterials. In this review paper are presented some of the most exciting and important developments in the synthesis, properties, and applications of low-dimensional carbon nanomaterials. In this part of the paper are presented the synthesis techniques used to produce the two-dimensional carbon nanomaterials (including graphene, and also the most important properties and potential applications of graphene.

Structural investigation of chemically synthesized ferrite magnetic nanomaterials

Science.gov (United States)

Uyanga, E.; Sangaa, D.; Hirazawa, H.; Tsogbadrakh, N.; Jargalan, N.; Bobrikov, I. A.; Balagurov, A. M.

2018-05-01

In recent times, interest in ferrite magnetic nanomaterials has considerably grown, mainly due to their highly promising medical and biological applications. Spinel ferrite powder samples, with high heat generation abilities in AC magnetic fields, were studied for their application to the hyperthermia treatment of cancer tumors. These properties of ferrites strongly depend on their chemical composition, ion distribution between crystallographic positions, magnetic structure and method of preparation. In this study, crystal and magnetic structures of several magnetic spinels were investigated by neutron diffraction. The explanation of the mechanism triggering the heat generation ability in the magnetic materials, and the electronic and magnetic states of ferrite-spinel type structures, were theoretically defined by a first-principles method. Ferrites with the composition of CuxMg1-xFe2O4 have been investigated as a heat generating magnetic nanomaterial. Atomic fraction of copper in ferrite was varied between 0 and 100% (that is, x between 0 and 1.0 with 0.2 steps), with the copper dope limit corresponding to appear a tetragonal phase.

Magnetism in carbon nanostructures

CERN Document Server

Hagelberg, Frank

2017-01-01

Magnetism in carbon nanostructures is a rapidly expanding field of current materials science. Its progress is driven by the wide range of applications for magnetic carbon nanosystems, including transmission elements in spintronics, building blocks of cutting-edge nanobiotechnology, and qubits in quantum computing. These systems also provide novel paradigms for basic phenomena of quantum physics, and are thus of great interest for fundamental research. This comprehensive survey emphasizes both the fundamental nature of the field, and its groundbreaking nanotechnological applications, providing a one-stop reference for both the principles and the practice of this emerging area. With equal relevance to physics, chemistry, engineering and materials science, senior undergraduate and graduate students in any of these subjects, as well as all those interested in novel nanomaterials, will gain an in-depth understanding of the field from this concise and self-contained volume.

Carbon nanomaterials for high-performance supercapacitors

OpenAIRE

Tao Chen; Liming Dai

2013-01-01

Owing to their high energy density and power density, supercapacitors exhibit great potential as high-performance energy sources for advanced technologies. Recently, carbon nanomaterials (especially, carbon nanotubes and graphene) have been widely investigated as effective electrodes in supercapacitors due to their high specific surface area, excellent electrical and mechanical properties. This article summarizes the recent progresses on the development of high-performance supercapacitors bas...

Carbon-Based Nanomaterials: Multi-Functional Materials for Biomedical Engineering

Science.gov (United States)

Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R.; Khademhosseini, Ali

2013-01-01

Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications. PMID:23560817

Recent applications of nanomaterials in capillary electrophoresis.

Science.gov (United States)

González-Curbelo, Miguel Ángel; Varela-Martínez, Diana Angélica; Socas-Rodríguez, Bárbara; Hernández-Borges, Javier

2017-10-01

Nanomaterials have found an important place in Analytical Chemistry and, in particular, in Separation Science. Among them, metal-organic frameworks, magnetic and non-magnetic nanoparticles, carbon nanotubes and graphene, as well as their combinations, are the most important nanomaterials that have been used up to now. Concerning capillary electromigration techniques, these nanomaterials have also been used as both pseudostationary phases in electrokinetic chromatography (EKC) and as stationary phases in microchip capillary electrophoresis (CE) and capillary electrochromatography (CEC), as a result of their interesting and particular properties. This review article pretends to provide a general and critical revision of the most recent applications of nanomaterials in this field (period 2010-2017). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performance Enhancement of Carbon Nanomaterials for Supercapacitors

OpenAIRE

Saleem, Amin M.; Desmaris, Vincent; Enoksson, Peter

2016-01-01

Carbon nanomaterials such as carbon nanotubes, carbon nanofibers, and graphene are exploited extensively due to their unique electrical, mechanical, and thermal properties and recently investigated for energy storage application (supercapacitor) due to additional high specific surface area and chemical inertness properties. The supercapacitor is an energy storage device which, in addition to long cycle life (one million), can give energy density higher than parallel plate capacitor and power ...

Non-metallic nanomaterials in cancer theranostics: a review of silica- and carbon-based drug delivery systems

International Nuclear Information System (INIS)

Chen, Yu-Cheng; Huang, Xin-Chun; Luo, Yun-Ling; Chang, Yung-Chen; Hsieh, You-Zung; Hsu, Hsin-Yun

2013-01-01

The rapid development in nanomaterials has brought great opportunities to cancer theranostics, which aims to combine diagnostics and therapy for cancer treatment and thereby improve the healthcare of patients. In this review we focus on the recent progress of several cancer theranostic strategies using mesoporous silica nanoparticles and carbon-based nanomaterials. Silicon and carbon are both group IV elements; they have been the most abundant and significant non-metallic substances in human life. Their intrinsic physical/chemical properties are of critical importance in the fabrication of multifunctional drug delivery systems. Responsive nanocarriers constructed using these nanomaterials have been promising in cancer-specific theranostics during the past decade. In all cases, either a controlled texture or the chemical functionalization is coupled with adaptive properties, such as pH-, light-, redox- and magnetic field- triggered responses. Several studies in cells and mice models have implied their underlying therapeutic efficacy; however, detailed and long-term in vivo clinical evaluations are certainly required to make these bench-made materials compatible in real bedside circumstances. (review)

Redox electrodes comprised of polymer-modified carbon nanomaterials

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Roberts, Mark; Emmett, Robert; Karakaya, Mehmet; Podila, Ramakrishna; Rao, Apparao; Clemson Physics Team; Clemson Chemical Engineering Team

2013-03-01

A shift in how we generate and use electricity requires new energy storage materials and systems compatible with hybrid electric transportation and the integration of renewable energy sources. Supercapacitors provide a solution to these needs by combining the high power, rapid switching, and exceptional cycle life of a capacitor with the high energy density of a battery. Our research brings together nanotechnology and materials chemistry to address the limitations of electrode materials. Paper electrodes fabricated with various forms of carbon nanomaterials, such as nanotubes, are modified with redox-polymers to increase the electrode's energy density while maintaining rapid discharge rates. In these systems, the carbon nanomaterials provide the high surface area, electrical conductivity, nanoscale and porosity, while the redox polymers provide a mechanism for charge storage through Faradaic charge transfer. The design of redox polymers and their incorporation into nanomaterial electrodes will be discussed with a focus on enabling high power and high energy density electrodes.

Non-covalently functionalized carbon nanostructures for synthesizing carbon-based hybrid nanomaterials.

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Li, Haiqing; Song, Sing I; Song, Ga Young; Kim, Il

2014-02-01

Carbon nanostructures (CNSs) such as carbon nanotubes, graphene sheets, and nanodiamonds provide an important type of substrate for constructing a variety of hybrid nanomaterials. However, their intrinsic chemistry-inert surfaces make it indispensable to pre-functionalize them prior to immobilizing additional components onto their surfaces. Currently developed strategies for functionalizing CNSs include covalent and non-covalent approaches. Conventional covalent treatments often damage the structure integrity of carbon surfaces and adversely affect their physical properties. In contrast, the non-covalent approach offers a non-destructive way to modify CNSs with desired functional surfaces, while reserving their intrinsic properties. Thus far, a number of surface modifiers including aromatic compounds, small-molecular surfactants, amphiphilic polymers, and biomacromolecules have been developed to non-covalently functionalize CNS surfaces. Mediated by these surface modifiers, various functional components such as organic species and inorganic nanoparticles were further decorated onto their surfaces, resulting in versatile carbon-based hybrid nanomaterials with broad applications in chemical engineering and biomedical areas. In this review, the recent advances in the generation of such hybrid nanostructures based on non-covalently functionalized CNSs will be reviewed.

Bacterial Cellulose: A Robust Platform for Design of Three Dimensional Carbon-Based Functional Nanomaterials.

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Wu, Zhen-Yu; Liang, Hai-Wei; Chen, Li-Feng; Hu, Bi-Cheng; Yu, Shu-Hong

2016-01-19

Three dimensional (3D) carbon nanomaterials exhibit great application potential in environmental protection, electrochemical energy storage and conversion, catalysis, polymer science, and advanced sensors fields. Current methods for preparing 3D carbon nanomaterials, for example, carbonization of organogels, chemical vapor deposition, and self-assembly of nanocarbon building blocks, inevitably involve some drawbacks, such as expensive and toxic precursors, complex equipment and technological requirements, and low production ability. From the viewpoint of practical application, it is highly desirable to develop a simple, cheap, and environmentally friendly way for fabricating 3D carbon nanomaterials in large scale. On the other hand, in order to extend the application scope and improve the performance of 3D carbon nanomaterials, we should explore efficient strategies to prepare diverse functional nanomaterials based on their 3D carbon structure. Recently, many researchers tend to fabricate high-performance 3D carbon-based nanomaterials from biomass, which is low cost, easy to obtain, and nontoxic to humans. Bacterial cellulose (BC), a typical biomass material, has long been used as the raw material of nata-de-coco (an indigenous dessert food of the Philippines). It consists of a polysaccharide with a β-1,4-glycosidic linkage and has a interconnected 3D porous network structure. Interestingly, the network is made up of a random assembly of cellulose nanofibers, which have a high aspect ratio with a diameter of 20-100 nm. As a result, BC has a high specific surface area. Additionally, BC hydrogels can be produced on an industrial scale via a microbial fermentation process at a very low price. Thus, it can be an ideal platform for design of 3D carbon-based functional nanomaterials. Before our work, no systematic work and summary on this topic had been reported. This Account presents the concepts and strategies of our studies on BC in the past few years, that is

Transparent Electrodes: A Review of the Use of Carbon-Based Nanomaterials

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Edgar J. López-Naranjo

2016-01-01

Full Text Available Transparent conducting electrodes (TCE are extensively applied in a great range of optoelectronic and photovoltaic equipment (e.g., solar cells, touch panels, and flexible devices. Carbon-based nanomaterials are considered as suitable replacements to substitute traditional materials to manufacture TCE due to their remarkable characteristics, for example, high optical transmittance and outstanding electrical properties. In comparison with traditional indium tin oxide electrodes, carbon-based electrodes show good mechanical properties, chemical stability, and low cost. Nevertheless, major issues related to the development of good quality manufacture methods to produce carbon-based nanomaterials have to be overcome to meet massive market requirements. Hence, the development of alternative TCE materials as well as appropriate large production techniques that meet the requirements of a proper sheet resistance along with a high optical transparency is a priority. Therefore, in this work, we summarize and discuss novel production and synthesis methods, chemical treatments, and hybrid materials developed to satisfy the worldwide request for carbon-based nanomaterials.

Predicted phototoxicities of carbon nano-material by quantum mechanical calculations

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The purpose of this research is to develop a predictive model for the phototoxicity potential of carbon nanomaterials (fullerenols and single-walled carbon nanotubes). This model is based on the quantum mechanical (ab initio) calculations on these carbon-based materials and compa...

Functionalization and Dispersion of Carbon Nanomaterials Using an Environmentally Friendly Ultrasonicated Ozonolysis Process.

Science.gov (United States)

Yeo, Eudora S Y; Mathys, Gary I; Brack, Narelle; Thostenson, Erik T; Rider, Andrew N

2017-05-30

Functionalization of carbon nanomaterials is often a critical step that facilitates their integration into larger material systems and devices. In the as-received form, carbon nanomaterials, such as carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs), may contain large agglomerates. Both agglomerates and impurities will diminish the benefits of the unique electrical and mechanical properties offered when CNTs or GNPs are incorporated into polymers or composite material systems. Whilst a variety of methods exist to functionalize carbon nanomaterials and to create stable dispersions, many the processes use harsh chemicals, organic solvents, or surfactants, which are environmentally unfriendly and may increase the processing burden when isolating the nanomaterials for subsequent use. The current research details the use of an alternative, environmentally friendly technique for functionalizing CNTs and GNPs. It produces stable, aqueous dispersions free of harmful chemicals. Both CNTs and GNPs can be added to water at concentrations up to 5 g/L and can be recirculated through a high-powered ultrasonic cell. The simultaneous injection of ozone into the cell progressively oxidizes the carbon nanomaterials, and the combined ultrasonication breaks down agglomerates and immediately exposes fresh material for functionalization. The prepared dispersions are ideally suited for the deposition of thin films onto solid substrates using electrophoretic deposition (EPD). CNTs and GNPs from the aqueous dispersions can be readily used to coat carbon- and glass-reinforcing fibers using EPD for the preparation of hierarchical composite materials.

Electrical discharge machining of carbon nanomaterials in air: machining characteristics and the advanced field emission applications

International Nuclear Information System (INIS)

Ok, Jong Girl; Kim, Bo Hyun; Chung, Do Kwan; Sung, Woo Yong; Lee, Seung Min; Lee, Se Won; Kim, Wal Jun; Park, Jin Woo; Chu, Chong Nam; Kim, Yong Hyup

2008-01-01

A reliable and precise machining process, electrical discharge machining (EDM), was investigated in depth as a novel method for the engineering of carbon nanomaterials. The machining characteristics of EDM applied to carbon nanomaterials 'in air' were systematically examined using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive x-ray spectroscopy (EDS), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The EDM process turned out to 'melt' carbon nanomaterials with the thermal energy generated by electrical discharge, which makes both the materially and geometrically unrestricted machining of nanomaterials possible. Since the EDM process conducted in air requires neither direct contact nor chemical agents, it protects the carbon nanomaterial workpieces against physical damage and unnecessary contamination. From this EDM method, several advanced field emission applications including 'top-down' patterning and the creative lateral comb-type triode device were derived, while our previously reported study on emission uniformity enhancement by the EDM method was also referenced. The EDM method has great potential as a clean, effective and practical way to utilize carbon nanomaterials for various uses

Applications of nanomaterials in sensors and diagnostics

Energy Technology Data Exchange (ETDEWEB)

Tuantranont, Adisorn (ed.) [National Electronics and Computer Technology Center (NECTEC), Pathumthani (Thailand). Nanoelectronics and MEMS Laboratory

2013-11-01

Recent progress in the synthesis of nanomaterials and our fundamental understanding of their properties has led to significant advances in nanomaterial-based gas, chemical and biological sensors. Leading experts around the world highlight the latest findings on a wide range of nanomaterials including nanoparticles, quantum dots, carbon nanotubes, molecularly imprinted nanostructures or plastibodies, nanometals, DNA-based structures, smart nanomaterials, nanoprobes, magnetic nanomaterials, organic molecules like phthalocyanines and porphyrins, and the most amazing novel nanomaterial, called graphene. Various sensing techniques such as nanoscaled electrochemical detection, functional nanomaterial-amplified optical assays, colorimetry, fluorescence and electrochemiluminescence, as well as biomedical diagnosis applications, e.g. for cancer and bone disease, are thoroughly reviewed and explained in detail. This volume will provide an invaluable source of information for scientists working in the field of nanomaterial-based technology as well as for advanced students in analytical chemistry, biochemistry, electrochemistry, material science, micro- and nanotechnology.

Green chemistry of carbon nanomaterials.

Science.gov (United States)

Basiuk, Elena V; Basiuk, Vladimir A

2014-01-01

The global trend of looking for more ecologically friendly, "green" techniques manifested itself in the chemistry of carbon nanomaterials. The main principles of green chemistry emphasize how important it is to avoid the use, or at least to reduce the consumption, of organic solvents for a chemical process. And it is precisely this aspect that was systematically addressed and emphasized by our research group since the very beginning of our work on the chemistry of carbon nanomaterials in early 2000s. The present review focuses on the results obtained to date on solvent-free techniques for (mainly covalent) functionalization of fullerene C60, single-walled and multi-walled carbon nanotubes (SWNTs and MWNTs, respectively), as well as nanodiamonds (NDs). We designed a series of simple and fast functionalization protocols based on thermally activated reactions with chemical compounds stable and volatile at 150-200 degrees C under reduced pressure, when not only the reactions take place at a high rate, but also excess reagents are spontaneously removed from the functionalized material, thus making its purification unnecessary. The main two classes of reagents are organic amines and thiols, including bifunctional ones, which can be used in conjunction with different forms of nanocarbons. The resulting chemical processes comprise nucleophilic addition of amines and thiols to fullerene C60 and to defect sites of pristine MWNTs, as well as direct amidation of carboxylic groups of oxidized nanotubes (mainly SWNTs) and ND. In the case of bifunctional amines and thiols, reactions of the second functional group can give rise to cross-linking effects, or be employed for further derivatization steps.

The applications of carbon nanomaterials in fiber-shaped energy storage devices

Science.gov (United States)

Wu, Jingxia; Hong, Yang; Wang, Bingjie

2018-01-01

As a promising candidate for future demand, fiber-shaped electrochemical energy storage devices, such as supercapacitors and lithium-ion batteries have obtained considerable attention from academy to industry. Carbon nanomaterials, such as carbon nanotube and graphene, have been widely investigated as electrode materials due to their merits of light weight, flexibility and high capacitance. In this review, recent progress of carbon nanomaterials in flexible fiber-shaped energy storage devices has been summarized in accordance with the development of fibrous electrodes, including the diversified electrode preparation, functional and intelligent device structure, and large-scale production of fibrous electrodes or devices. Project supported by the National Natural Science Foundation of China (Nos. 21634003, 21604012).

A Review of the Synthesis and Photoluminescence Properties of Hybrid ZnO and Carbon Nanomaterials

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Protima Rauwel

2016-01-01

Full Text Available Photoluminescent ZnO carbon nanomaterials are an emerging class of nanomaterials with unique optical properties. They each, ZnO and carbon nanomaterials, have an advantage of being nontoxic and environmentally friendly. Their cost-effective production methods along with simple synthesis routes are also of interest. Moreover, ZnO presents photoluminescence emission in the UV and visible region depending on the synthesis routes, shape, size, deep level, and surface defects. When combined with carbon nanomaterials, modification of surface defects in ZnO allows tuning of these photoluminescence properties to produce, for example, white light. Moreover, efficient energy transfer from the ZnO to carbon nanostructures makes them suitable candidates not only in energy harvesting applications but also in biosensors, photodetectors, and low temperature thermal imaging. This work reviews the synthesis and photoluminescence properties of 3 carbon allotropes: carbon quantum or nanodots, graphene, and carbon nanotubes when hybridized with ZnO nanostructures. Various synthesis routes for the hybrid materials with different morphologies of ZnO are presented. Moreover, differences in photoluminescence emission when combining ZnO with each of the three different allotropes are analysed.

PREFACE: Ultrafast and nonlinear optics in carbon nanomaterials

Science.gov (United States)

Kono, Junichiro

2013-02-01

Journal of Physics: Condensed Matter staff for their help, patience and professionalism. Since this is a fast-moving field, there is absolutely no way of presenting definitive answers to all open questions, but we hope that this special section will provide an overview of the current state of knowledge regarding this topic. Furthermore, we hope that the exciting science and technology described in this section will attract and inspire other researchers and students working in related fields to enter into the study of ultrafast and nonlinear optical phenomena in carbon-based nanostructures. Ultrafast and nonlinear optics in carbon nanomaterials contents Ultrafast and nonlinear optics in carbon nanomaterialsJunichiro Kono The impact of pump fluence on carrier relaxation dynamics in optically excited grapheneT Winzer and E Malic Time-resolved spectroscopy on epitaxial graphene in the infrared spectral range: relaxation dynamics and saturation behaviorS Winnerl, F Göttfert, M Mittendorff, H Schneider, M Helm, T Winzer, E Malic, A Knorr, M Orlita, M Potemski, M Sprinkle, C Berger and W A de Heer Nonlinear optics of graphene in a strong magnetic fieldXianghan Yao and Alexey Belyanin Theory of coherent phonons in carbon nanotubes and graphene nanoribbonsG D Sanders, A R T Nugraha, K Sato, J-H Kim3, J Kono3, R Saito and C J Stanton Non-perturbative effects of laser illumination on the electrical properties of graphene nanoribbons Hernán L Calvo, Pablo M Perez-Piskunow, Horacio M Pastawski, Stephan Roche and Luis E F Foa Torres Transient absorption microscopy studies of energy relaxation in graphene oxide thin film Sean Murphy and Libai Huang Femtosecond dynamics of exciton localization: self-trapping from the small to the large polaron limit F X Morrissey, J G Mance, A D Van Pelt and S L Dexheimer

Thermionic Properties of Carbon Based Nanomaterials Produced by Microhollow Cathode PECVD

Science.gov (United States)

Haase, John R.; Wolinksy, Jason J.; Bailey, Paul S.; George, Jeffrey A.; Go, David B.

2015-01-01

Thermionic emission is the process in which materials at sufficiently high temperature spontaneously emit electrons. This process occurs when electrons in a material gain sufficient thermal energy from heating to overcome the material's potential barrier, referred to as the work function. For most bulk materials very high temperatures (greater than 1500 K) are needed to produce appreciable emission. Carbon-based nanomaterials have shown significant promise as emission materials because of their low work functions, nanoscale geometry, and negative electron affinity. One method of producing these materials is through the process known as microhollow cathode PECVD. In a microhollow cathode plasma, high energy electrons oscillate at very high energies through the Pendel effect. These high energy electrons create numerous radical species and the technique has been shown to be an effective method of growing carbon based nanomaterials. In this work, we explore the thermionic emission properties of carbon based nanomaterials produced by microhollow cathode PECVD under a variety of synthesis conditions. Initial studies demonstrate measureable current at low temperatures (approximately 800 K) and work functions (approximately 3.3 eV) for these materials.

Low-toxic and safe nanomaterials by surface-chemical design, carbon nanotubes, fullerenes, metallofullerenes, and graphenes

Science.gov (United States)

YanEqual Contribution, Liang; Zhao, Feng; Li, Shoujian; Hu, Zhongbo; Zhao, Yuliang

2011-02-01

The toxicity grade for a bulk material can be approximately determined by three factors (chemical composition, dose, and exposure route). However, for a nanomaterial it depends on more than ten factors. Interestingly, some nano-factors (like huge surface adsorbability, small size, etc.) that endow nanomaterials with new biomedical functions are also potential causes leading to toxicity or damage to the living organism. Is it possible to create safe nanomaterials if such a number of complicated factors need to be regulated? We herein try to find answers to this important question. We first discuss chemical processes that are applicable for nanosurface modifications, in order to improve biocompatibility, regulate ADME, and reduce the toxicity of carbon nanomaterials (carbon nanotubes, fullerenes, metallofullerenes, and graphenes). Then the biological/toxicological effects of surface-modified and unmodified carbon nanomaterials are comparatively discussed from two aspects: the lowered toxic responses or the enhanced biomedical functions. We summarize the eight biggest challenges in creating low-toxicity and safer nanomaterials and some significant topics of future research needs: to find out safer nanofactors; to establish controllable surface modifications and simpler chemistries for low-toxic nanomaterials; to explore the nanotoxicity mechanisms; to justify the validity of current toxicological theories in nanotoxicology; to create standardized nanomaterials for toxicity tests; to build theoretical models for cellular and molecular interactions of nanoparticles; and to establish systematical knowledge frameworks for nanotoxicology.

Roles of Direct and Indirect Light-Induced Transformations of Carbon Nanomaterials in Exposures in Aquatic Systems

Science.gov (United States)

Carbon nanomaterials (CNMs) such as fullerenes, carbon nanotubes and graphene-based nanomaterials have a variety of useful characteristics such as extraordinary electron and heat conducting abilities, optical absorption and mechanical properties, and potential applications in tra...

Multi-functional carbon nanomaterials: Tailoring morphology for multidisciplinary applications

Energy Technology Data Exchange (ETDEWEB)

Dervishi, Enkeleda [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-05-14

Carbon based nanomaterials are being developed to have many new properties and applications. Graphene, is a mono-layer 2D atomic thick structure formed from hexagons of carbon atoms bound together by sp^2hybrid bonds. A carbon nanotube (CNT) can be viewed as a sheet of graphene rolled up into a cylinder, usually 1-2 nanometers in diameter and a few microns thick. A few applications of graphene and carbon nanotubes include the development of Nanoelectronics, nanocomposite materials, Hydrogen storage and Li⁺ battery, etc.

Nanofabrication and Nanopatterning of Carbon Nanomaterials for Flexible Electronics

Science.gov (United States)

Ding, Junjun

Stretchable electrodes have increasingly drawn attention as a vital component for flexible electronic devices. Carbon nanomaterials such as graphene and carbon nanotubes (CNTs) exhibit properties such as high mechanical flexibility and strength, optical transparency, and electrical conductivity which are naturally required for stretchable electrodes. Graphene growth, nanopatterning, and transfer processes are important steps to use graphene as flexible electrodes. However, advances in the large-area nanofabrication and nanopatterning of carbon nanomaterials such as graphene are necessary to realize the full potential of this technology. In particular, laser interference lithography (LIL), a fast and low cost large-area nanoscale patterning technique, shows tremendous promise for the patterning of graphene and other nanostructures for numerous applications. First, it was demonstrated that large-area nanopatterning and the transfer of chemical vapor deposition (CVD) grown graphene via LIL and plasma etching provide a reliable method to provide large area nanoengineered graphene on various target substrates. Then, to improve the electrode performance under large strain (naturally CVD grown graphene sheet will crack at tensile strains larger than 1%), a corrugated graphene structure on PDMS was designed, fabricated, and tested, with experimental results indicating that this approach successfully allows the graphene sheets to withstand cyclic tensile strains up to 15%. Lastly, to further enhance the performance of carbon-based stretchable electrodes, an approach was developed which coupled graphene and vertically aligned CNT (VACNT) on a flexible PDMS substrate. Characterization of the graphene-VACNT hybrid shows high electrical conductivity and durability through 50 cycles of loading up to 100% tensile strain. While flexible electronics promise tremendous advances in important technological areas such as healthcare, sensing, energy, and wearable electronics, continued

Environmental Risk Assessment of Nanomaterials

Science.gov (United States)

Bayramov, A. A.

In this paper, various aspects of modern nanotechnologies and, as a result, risks of nanomaterials impact on an environment are considered. This very brief review of the First International Conference on Material and Information Sciences in High Technologies (2007, Baku, Azerbaijan) is given. The conference presented many reports that were devoted to nanotechnology in biology and business for the developing World, formation of charged nanoparticles for creation of functional nanostructures, nanoprocessing of carbon nanotubes, magnetic and optical properties of manganese-phosphorus nanowires, ultra-nanocrystalline diamond films, and nanophotonics communications in Azerbaijan. The mathematical methods of simulation of the group, individual and social risks are considered for the purpose of nanomaterials risk reduction and remediation. Lastly, we have conducted studies at a plant of polymeric materials (and nanomaterials), located near Baku. Assessments have been conducted on the individual risk of person affection and constructed the map of equal isolines and zones of individual risk for a plant of polymeric materials (and nanomaterials).

Effect of the graphite electrode material on the characteristics of molten salt electrolytically produced carbon nanomaterials

International Nuclear Information System (INIS)

Kamali, Ali Reza; Schwandt, Carsten; Fray, Derek J.

2011-01-01

The electrochemical erosion of a graphite cathode during the electrolysis of molten lithium chloride salt may be used for the preparation of nano-structured carbon materials. It has been found that the structures and morphologies of these carbon nanomaterials are dependent on those of the graphite cathodes employed. A combination of tubular and spherical carbon nanostructures has been produced from a graphite with a microstructure of predominantly planar micro-sized grains and a minor fraction of more irregular nano-sized grains, whilst only spherical carbon nanostructures have been produced from a graphite with a microstructure of primarily nano-sized grains. Based on the experimental results, a best-fit regression equation is proposed that relates the crystalline domain size of the graphite reactants and the carbon products. The carbon nanomaterials prepared possess a fairly uniform mesoporosity with a sharp peak in pore size distribution at around 4 nm. The results are of crucial importance to the production of carbon nanomaterials by way of the molten salt electrolytic method. - Highlights: → Carbon nanomaterials are synthesised by LiCl electrolysis with graphite electrodes. → The degree of crystallinity of graphite reactant and carbon product are related. → A graphite reactant is identified that enables the preparation of carbon nanotubes. → The carbon products possess uniform mesoporosity with narrow pore size distribution.

Four- and eight-membered rings carbon nanotubes: A new class of carbon nanomaterials

Science.gov (United States)

Li, Fangfang; Lu, Junzhe; Zhu, Hengjiang; Lin, Xiang

2018-06-01

A new class of carbon nanomaterials composed of alternating four- and eight-membered rings is studied by density functional theory (DFT), including single-walled carbon nanotubes (SWCNTs) double-walled carbon nanotubes (DWCNTs) and triple-walled CNTs (TWCNTs). The analysis of geometrical structure shows that carbon atoms' hybridization in novel carbon tubular clusters (CTCs) and the corresponding carbon nanotubes (CNTs) are both sp2 hybridization; The thermal properties exhibit the high stability of these new CTCs. The results of energy band and density of state (DOS) indicate that the electronic properties of CNTs are independent of their diameter, number of walls and chirality, exhibit obvious metal properties.

Key physicochemical properties of nanomaterials in view of their toxicity: an exploratory systematic investigation for the example of carbon-based nanomaterial

International Nuclear Information System (INIS)

Salieri, Beatrice; Pasteris, Andrea; Netkueakul, Woranan; Hischier, Roland

2017-01-01

Currently, a noncomprehensive understanding of the physicochemical properties of carbon-based nanomaterial (CBNs), which may affect toxic effects, is still observable. In this study, an exploratory systematic investigation into the key physicochemical properties of multiwall carbon nanotube (MWCNT), single-wall carbon nanotube (SWCNT), and C_6_0-fullerene on their ecotoxicity has been undertaken. We undertook an extensive survey of the literature pertaining to the ecotoxicity of organism representative of the trophic level of algae, crustaceans, and fish. Based on this, a set of data reporting both the physicochemical properties of carbon-based nanomaterial and the observed toxic effect has been established. The relationship between physicochemical properties and observed toxic effect was investigated based on various statistical approaches. Specifically, analysis of variance by one-way ANOVA was used to assess the effect of categorical properties (use of a dispersant or treatments in the test medium, type of carbon-based nanomaterial, i.e., SWCNT, MWCNT, C_6_0-fullerene, functionalization), while multiple regression analysis was used to assess the effect of quantitative properties (i.e., diameter length of nanotubes, secondary size) on the toxicity values. The here described investigations revealed significant relationships among the physicochemical properties and observed toxic effects. The research was mainly affected by the low availability of data and also by the low variability of the studies collected. Overall, our results demonstrate that the here proposed and applied approach could have a major role in identifying the physicochemical properties of relevance for the toxicity of nanomaterial. However, the future success of the approach would require that the ENMs and the experimental conditions used in the toxicity studies are fully characterized.

Key physicochemical properties of nanomaterials in view of their toxicity: an exploratory systematic investigation for the example of carbon-based nanomaterial

Energy Technology Data Exchange (ETDEWEB)

Salieri, Beatrice, E-mail: Beatrice.salieri@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Lab (Switzerland); Pasteris, Andrea [University of Bologna, Department of Biological, Geological, and Environmental Sciences (Italy); Netkueakul, Woranan; Hischier, Roland [Empa, Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Lab (Switzerland)

2017-03-15

Currently, a noncomprehensive understanding of the physicochemical properties of carbon-based nanomaterial (CBNs), which may affect toxic effects, is still observable. In this study, an exploratory systematic investigation into the key physicochemical properties of multiwall carbon nanotube (MWCNT), single-wall carbon nanotube (SWCNT), and C{sub 60}-fullerene on their ecotoxicity has been undertaken. We undertook an extensive survey of the literature pertaining to the ecotoxicity of organism representative of the trophic level of algae, crustaceans, and fish. Based on this, a set of data reporting both the physicochemical properties of carbon-based nanomaterial and the observed toxic effect has been established. The relationship between physicochemical properties and observed toxic effect was investigated based on various statistical approaches. Specifically, analysis of variance by one-way ANOVA was used to assess the effect of categorical properties (use of a dispersant or treatments in the test medium, type of carbon-based nanomaterial, i.e., SWCNT, MWCNT, C{sub 60}-fullerene, functionalization), while multiple regression analysis was used to assess the effect of quantitative properties (i.e., diameter length of nanotubes, secondary size) on the toxicity values. The here described investigations revealed significant relationships among the physicochemical properties and observed toxic effects. The research was mainly affected by the low availability of data and also by the low variability of the studies collected. Overall, our results demonstrate that the here proposed and applied approach could have a major role in identifying the physicochemical properties of relevance for the toxicity of nanomaterial. However, the future success of the approach would require that the ENMs and the experimental conditions used in the toxicity studies are fully characterized.

Adsorption of Phenol from Aqueous Solutions by Carbon Nanomaterials of One and Two Dimensions: Kinetic and Equilibrium Studies

Directory of Open Access Journals (Sweden)

M. de la Luz-Asunción

2015-01-01

Full Text Available Carbon nanomaterials have a great potential in environmental studies; they are considered as superior adsorbents of pollutants due to their physical and chemical properties. Functionalization and dimension play an important role in many functions of these nanomaterials including adsorption. In this research, adsorption process was achieved with one-dimension nanomaterials: single walled and multiwalled carbon nanotubes were used as received and after oxidation treatment also two-dimensional nanomaterials were used: graphene oxide and reduced graphene oxide. Carbon nanotubes were modified by hydrogen peroxide under microwave irradiation. The reduction of graphene oxide was achieved by using ascorbic acid. R2 values obtained with the pseudo-second-order model are higher than 0.99. The results demonstrate that Freundlich isotherm provides the best fit for the equilibrium data (R2>0.94. RL values are between 0 and 1; this represents favorable adsorption between carbon nanomaterials and phenol. The adsorption process occurs by π-π interactions and hydrogen bonding and not by electrostatic interactions. The results indicate that the adsorption of phenol on carbon nanomaterials depends on the adsorbents’ surface area, and it is negatively influenced by the presence of oxygenated groups.

99mTc labeling of carbon nanomaterials

International Nuclear Information System (INIS)

Chu Ying; Li Qingnuan; Li Wenxin; Li Yufeng; Zhang Xiaoyong

2008-01-01

The effects of experimental conditions on preparation of 99m Tc-labeled carbon nanotubes and nanocarbon blacks by SnCl 2 were investigated. At given conditions the labeling yields were over 90%. In a culture medium, the radiochemical purity of the labeling compounds kept (86 ± 4)% within 2.5 h. The 99m Tc-labeled MWNTs and NCBs obtained in this work meet satisfactory experimental demands for study of cellular uptake and toxicity. The experiments showed that labeling process was based on physical adsorption of low valent technetium resulted from reduction reaction on the surface of the carbon nanomaterials. (authors)

Biological and ecological responses to carbon-based nanomaterials

Science.gov (United States)

Ratnikova, Tatsiana A.

This dissertation examines the biological and ecological responses to carbon nanoparticles, a major class of nanomaterials which have been mass produced and extensively studied for their rich physical properties and commercial values. Chapter I of this dissertation offers a comprehensive review on the structures, properties, applications, and implications of carbon nanomaterials, especially related to the perspectives of biological and ecosystems. Given that there are many types of carbon nanomaterials available, this chapter is focused on three major types of carbon-based nanomaterials only, namely, fullerenes, single walled and multi-walled carbon nanotubes. On the whole organism level, specifically, Chapter II presents a first study on the fate of fullerenes and multiwalled carbon nanotubes in rice plants, which was facilitated by the self assembly of these nanomaterials with NOM. The aspects of fullerene uptake, translocation, biodistribution, and generational transfer in the plants were examined and quantified using bright field and electron microscopy, FT-Raman, and FTIR spectroscopy. The uptake and transport of fullerene in the plant vascular system were attributed to water transpiration, convection, capillary force, and the fullerene concentration gradient from the roots to the leaves of the plants. On the cellular level, Chapter III documents the differential uptake of hydrophilic C60(OH)20 vs. amphiphilic C70-NOM complex in Allium cepa plant cells and HT-29 colon carcinoma cells. This study was conducted using a plant cell viability assay, and complemented by bright field, fluorescence and electron microscopy imaging. In particular, C60(OH)20 and C70-NOM showed contrasting uptake in both the plant and mammalian cells, due to their significant differences in physicochemistry and the presence of an extra hydrophobic plant cell wall in the plant cells. Consequently, C60(OH)20 was found to induce toxicity in Allium cepa cells but not in HT-29 cells, while C70

Experimentally evaluating the origin of dilute magnetism in nanomaterials

International Nuclear Information System (INIS)

Pereira, L M C

2017-01-01

Reports of room-temperature ferromagnetism continue to emerge for an ever-growing range of nanomaterials with a small or even vanishing concentration of magnetic atoms. Dilute magnetic semiconductors (DMS) are the most representative class of such materials, but similar magnetic properties have been reported in many others. Challenging our understanding of magnetic order in solids, as well as our ability to experimentally assess it, these remarkable magnetic phenomena have become one of the most controversial topics in magnetism. Various non-intrinsic sources of ferromagnetism (e.g. instrumental artifacts and magnetic contamination) are becoming well documented, and rarely are all of them taken into account when room-temperature ferromagnetism is reported. This topical review is intended to serve as a guide when evaluating to what extent a given data set supports the claim of intrinsic ferromagnetism in dilute nanomaterials. It compiles the most relevant sources of non-intrinsic ferromagnetism which have been reported, as well as guidelines for how to minimize them. It also provides an overview of complementary structural and magnetic characterization techniques which can be combined to provide different levels of scrutiny of the intrinsic nature of experimentally observed ferromagnetism. In particular, it gives some notable examples of how comprehensive studies based on those techniques have led to a remarkably detailed understanding of model DMS materials, with strong evidence of absence of room-temperature ferromagnetism. Although mostly based on DMS research, this review provides a set of guidelines and cautionary notes of broader relevance, including some emerging new fields of dilute nanomagnetism such as magnetically doped 3D topological insulators, 3D Dirac semimetals, and 2D materials. (topical review)

Experimentally evaluating the origin of dilute magnetism in nanomaterials

Science.gov (United States)

Pereira, L. M. C.

2017-10-01

Reports of room-temperature ferromagnetism continue to emerge for an ever-growing range of nanomaterials with a small or even vanishing concentration of magnetic atoms. Dilute magnetic semiconductors (DMS) are the most representative class of such materials, but similar magnetic properties have been reported in many others. Challenging our understanding of magnetic order in solids, as well as our ability to experimentally assess it, these remarkable magnetic phenomena have become one of the most controversial topics in magnetism. Various non-intrinsic sources of ferromagnetism (e.g. instrumental artifacts and magnetic contamination) are becoming well documented, and rarely are all of them taken into account when room-temperature ferromagnetism is reported. This topical review is intended to serve as a guide when evaluating to what extent a given data set supports the claim of intrinsic ferromagnetism in dilute nanomaterials. It compiles the most relevant sources of non-intrinsic ferromagnetism which have been reported, as well as guidelines for how to minimize them. It also provides an overview of complementary structural and magnetic characterization techniques which can be combined to provide different levels of scrutiny of the intrinsic nature of experimentally observed ferromagnetism. In particular, it gives some notable examples of how comprehensive studies based on those techniques have led to a remarkably detailed understanding of model DMS materials, with strong evidence of absence of room-temperature ferromagnetism. Although mostly based on DMS research, this review provides a set of guidelines and cautionary notes of broader relevance, including some emerging new fields of dilute nanomagnetism such as magnetically doped 3D topological insulators, 3D Dirac semimetals, and 2D materials.

Applied spectroscopy and the science of nanomaterials

CERN Document Server

2015-01-01

This book focuses on several areas of intense topical interest related to applied spectroscopy and the science of nanomaterials. The eleven chapters in the book cover the following areas of interest relating to applied spectroscopy and nanoscience: ·         Raman spectroscopic characterization, modeling and simulation studies of carbon nanotubes, ·         Characterization of plasma discharges using laser optogalvanic spectroscopy, ·         Fluorescence anisotropy in understanding protein conformational disorder and aggregation, ·         Nuclear magnetic resonance spectroscopy in nanomedicine, ·         Calculation of Van der Waals interactions at the nanoscale, ·         Theory and simulation associated with adsorption of gases in nanomaterials, ·         Atom-precise metal nanoclusters, ·         Plasmonic properties of metallic nanostructures, two-dimensional materials, and their composites, ·         Applications of graphe...

Carbon Nanomaterials Based Electrochemical Sensors/Biosensors for the Sensitive Detection of Pharmaceutical and Biological Compounds

Directory of Open Access Journals (Sweden)

Bal-Ram Adhikari

2015-09-01

Full Text Available Electrochemical sensors and biosensors have attracted considerable attention for the sensitive detection of a variety of biological and pharmaceutical compounds. Since the discovery of carbon-based nanomaterials, including carbon nanotubes, C60 and graphene, they have garnered tremendous interest for their potential in the design of high-performance electrochemical sensor platforms due to their exceptional thermal, mechanical, electronic, and catalytic properties. Carbon nanomaterial-based electrochemical sensors have been employed for the detection of various analytes with rapid electron transfer kinetics. This feature article focuses on the recent design and use of carbon nanomaterials, primarily single-walled carbon nanotubes (SWCNTs, reduced graphene oxide (rGO, SWCNTs-rGO, Au nanoparticle-rGO nanocomposites, and buckypaper as sensing materials for the electrochemical detection of some representative biological and pharmaceutical compounds such as methylglyoxal, acetaminophen, valacyclovir, β-nicotinamide adenine dinucleotide hydrate (NADH, and glucose. Furthermore, the electrochemical performance of SWCNTs, rGO, and SWCNT-rGO for the detection of acetaminophen and valacyclovir was comparatively studied, revealing that SWCNT-rGO nanocomposites possess excellent electrocatalytic activity in comparison to individual SWCNT and rGO platforms. The sensitive, reliable and rapid analysis of critical disease biomarkers and globally emerging pharmaceutical compounds at carbon nanomaterials based electrochemical sensor platforms may enable an extensive range of applications in preemptive medical diagnostics.

Electrodeposition of Copper/Carbonous Nanomaterial Composite Coatings for Heat-Dissipation Materials

Directory of Open Access Journals (Sweden)

Yasuki Goto

2017-12-01

Full Text Available Carbonous nanomaterials are promising additives for composite coatings for heat-dissipation materials because of their excellent thermal conductivity. Here, copper/carbonous nanomaterial composite coatings were prepared using nanodiamond (ND as the carbonous nanomaterial. The copper/ND composite coatings were electrically deposited onto copper substrates from a continuously stirred copper sulfate coating bath containing NDs. NDs were dispersed by ultrasonic treatment, and the initial bath pH was adjusted by adding sodium hydroxide solution or sulfuric acid solution before electrodeposition. The effects of various coating conditions—the initial ND concentration, initial bath pH, stirring speed, electrical current density, and the amount of electricity—on the ND content of the coatings were investigated. Furthermore, the surface of the NDs was modified by hydrothermal treatment to improve ND incorporation. A higher initial ND concentration and a higher stirring speed increased the ND content of the coatings, whereas a higher initial bath pH and a greater amount of electricity decreased it. The electrical current density showed a minimum ND content at approximately 5 A/dm2. Hydrothermal treatment, which introduced carboxyl groups onto the ND surface, improved the ND content of the coatings. A copper/ND composite coating with a maximum of 3.85 wt % ND was obtained.

Four- and eight-membered rings carbon nanotubes: A new class of carbon nanomaterials

Directory of Open Access Journals (Sweden)

Fangfang Li

2018-06-01

Full Text Available A new class of carbon nanomaterials composed of alternating four- and eight-membered rings is studied by density functional theory (DFT, including single-walled carbon nanotubes (SWCNTs double-walled carbon nanotubes (DWCNTs and triple-walled CNTs (TWCNTs. The analysis of geometrical structure shows that carbon atoms’ hybridization in novel carbon tubular clusters (CTCs and the corresponding carbon nanotubes (CNTs are both sp2 hybridization; The thermal properties exhibit the high stability of these new CTCs. The results of energy band and density of state (DOS indicate that the electronic properties of CNTs are independent of their diameter, number of walls and chirality, exhibit obvious metal properties. Keywords: Four- and eight-membered rings, Carbon nanotubes, Stability, Electronic properties

Not just graphene: The wonderful world of carbon and related nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Gogotsi, Yury

2015-11-27

Carbon, with its variety of allotropes and forms, is the most versatile material, and virtually any combination of mechanical, optical, electrical, and chemical properties can be achieved with carbon by controlling its structure and surface chemistry. The goal of this article is to help readers appreciate the variety of carbon nanomaterials and to describe some engineering applications of the most important of these. Many different materials are needed to meet a variety of performance requirements, but they can all be built of carbon. Considering the example of supercapacitor electrodes, zero- and one-dimensional nanoparticles, such as carbon onions and nanotubes, respectively, deliver very high power because of fast ion sorption/desorption on their outer surfaces. Two-dimensional (2D) graphene offers higher charge/discharge rates than porous carbons and a high volumetric energy density. Three-dimensional porous activated, carbide-derived, and templated carbon networks, with high surface areas and porosities in the angstrom or nanometer range, can provide high energy densities if the pore size is matched with the electrolyte ion size. Finally, carbon-based nanostructures further expand the range of available nanomaterials: Recently discovered 2D transition-metal carbides (MXenes) have already grown into a family with close to 20 members in about four years and challenge graphene in some applications.

Nanomaterials for Hydrogen Storage Applications: A Review

Directory of Open Access Journals (Sweden)

Michael U. Niemann

2008-01-01

Full Text Available Nanomaterials have attracted great interest in recent years because of the unusual mechanical, electrical, electronic, optical, magnetic and surface properties. The high surface/volume ratio of these materials has significant implications with respect to energy storage. Both the high surface area and the opportunity for nanomaterial consolidation are key attributes of this new class of materials for hydrogen storage devices. Nanostructured systems including carbon nanotubes, nano-magnesium based hydrides, complex hydride/carbon nanocomposites, boron nitride nanotubes, TiS2/MoS2 nanotubes, alanates, polymer nanocomposites, and metal organic frameworks are considered to be potential candidates for storing large quantities of hydrogen. Recent investigations have shown that nanoscale materials may offer advantages if certain physical and chemical effects related to the nanoscale can be used efficiently. The present review focuses the application of nanostructured materials for storing atomic or molecular hydrogen. The synergistic effects of nanocrystalinity and nanocatalyst doping on the metal or complex hydrides for improving the thermodynamics and hydrogen reaction kinetics are discussed. In addition, various carbonaceous nanomaterials and novel sorbent systems (e.g. carbon nanotubes, fullerenes, nanofibers, polyaniline nanospheres and metal organic frameworks etc. and their hydrogen storage characteristics are outlined.

Semiconducting, Magnetic or Superconducting Nanoparticles encapsulated in Carbon Shells by RAPET method.

Directory of Open Access Journals (Sweden)

Aharon Gedanken

2008-06-01

Full Text Available An efficient, solvent-free, environmentally friendly, RAPET (Reactions under Autogenic Pressure at Elevated Temperaturesynthetic approach is discussed for the fabrication of core-shell nanostructures. The semiconducting, magnetic orsuperconducting nanoparticles are encapsulated in a carbon shell. RAPET is a one-step, thermal decomposition reaction ofchemical compound (s followed by the formation of core-shell nanoparticles in a closed stainless steel reactor. Therepresentative examples are discussed, where a variety of nanomaterials are trapped in situ in a carbon shell that offersfascinating properties.

A graphene oxide-carbon nanotube grid for high-resolution transmission electron microscopy of nanomaterials

International Nuclear Information System (INIS)

Zhang Lina; Zhang Haoxu; Zhou Ruifeng; Chen Zhuo; Li Qunqing; Fan Shoushan; Jiang Kaili; Ge Guanglu; Liu Renxiao

2011-01-01

A novel grid for use in transmission electron microscopy is developed. The supporting film of the grid is composed of thin graphene oxide films overlying a super-aligned carbon nanotube network. The composite film combines the advantages of graphene oxide and carbon nanotube networks and has the following properties: it is ultra-thin, it has a large flat and smooth effective supporting area with a homogeneous amorphous appearance, high stability, and good conductivity. The graphene oxide-carbon nanotube grid has a distinct advantage when characterizing the fine structure of a mass of nanomaterials over conventional amorphous carbon grids. Clear high-resolution transmission electron microscopy images of various nanomaterials are obtained easily using the new grids.

Experimental investigation of interactions between proteins and carbon nanomaterials

Science.gov (United States)

Sengupta, Bishwambhar

The global market for nanomaterials based products is forecasted to reach $1 trillion per annum per annum for 2015. Engineered nanomaterials (ENMs) exhibit unique physicochemical properties with potential to impact diverse aspects of society through applications in electronics, renewable energy, and medicine. While the research and proposed applications of ENMs continue to grow rapidly, the health and safety of ENMs still remains a major concern to the public as well as to policy makers and funding agencies. It is now widely accepted that focused efforts are needed for identifying the list of physicochemical descriptors of ENM before they can be evaluated for nanotoxicity and biological response. This task is surprisingly challenging, as many physicochemical properties of ENMs are closely inter related and cannot be varied independently (e.g. increasing the size of an ENM can introduce additional defects). For example, varying toxic response may ensue due to different methods of nanomaterial preparation, dissimilar impurities and defects. Furthermore, the inadvertent coating of proteins on ENM surface in any biological milieu results in the formation of the so-called "protein/bio-corona" which can in turn alter the fate of ENMs and their biological response. Carbon nanomaterials (CNMs) such as carbon nanotubes, graphene, and graphene oxide are widely used ENMs. It is now known that defects in CNMs play an important role not only in materials properties but also in the determination of how materials interact at the nano-bio interface. In this regard, this work investigates the influence of defect-induced hydrophilicity on the bio-corona formation using micro Raman, photoluminescence, infrared spectroscopy, electrochemistry, and molecular dynamics simulations. Our results show that the interaction of proteins (albumin and fibrinogen) with CNMs is strongly influenced by charge transfer between them, inducing protein unfolding which enhances conformational entropy and

Films of Carbon Nanomaterials for Transparent Conductors

Directory of Open Access Journals (Sweden)

Jun Wei

2013-05-01

Full Text Available The demand for transparent conductors is expected to grow rapidly as electronic devices, such as touch screens, displays, solid state lighting and photovoltaics become ubiquitous in our lives. Doped metal oxides, especially indium tin oxide, are the commonly used materials for transparent conductors. As there are some drawbacks to this class of materials, exploration of alternative materials has been conducted. There is an interest in films of carbon nanomaterials such as, carbon nanotubes and graphene as they exhibit outstanding properties. This article reviews the synthesis and assembly of these films and their post-treatment. These processes determine the film performance and understanding of this platform will be useful for future work to improve the film performance.

Formula of an ideal carbon nanomaterial supercapacitor

Science.gov (United States)

Samuilova, Larissa; Frenkel, Alexander; Samuilov, Vladimir

2014-03-01

Supercapacitors exhibit great potential as high-performance energy sources for a large variety of potential applications, ranging from consumer electronics through wearable optoelectronics to hybrid electric vehicles. We focuse on carbon nanomaterials, especially carbon nanotube films, 3-D graphene, graphene oxide due to their high specific surface area, excellent electrical and mechanical properties. We have developed a simple approach to lower the equivalent series resistance by fabricating electrodes of arbitrary thickness using carbon nanotube films and reduced graphene oxide based composites. Besides of the problem of increasing of the capacitance, the minimization of the loss tangent (dissipation factor) is marginal for the future development of the supercapacitors. This means, not only a very well developed surface area of the electrodes, but the role of the good quality of the porous separator and the electrolyte are important. We address these factors as well.

A viable way to tailor carbon nanomaterials by irradiation-induced transformations

International Nuclear Information System (INIS)

Caudillo, R.; Troiani, H.E.; Miki-Yoshida, M.; Marques, M.A.L.; Rubio, A.; Yacaman, M.J.

2005-01-01

Since the discovery of carbon nanotubes (CNT), transmission electron microscopy (TEM) has been the most important tool in their investigation. It is possible to use electron irradiation in a TEM to construct a single-walled carbon nanotube (SWCNT) from an amorphous carbon film. Here we show that such a synthesis method creates a large number of carbon ad-atoms, which after some critical amount of radiation act to restore the system by reconstructing the carbon film. The behavior of the ad-atoms can be controlled by adjusting the current density in the microscope, suggesting that carbon nanomaterials can be tailored by electron irradiation

Point and Line to Plane: The Ontography of Carbon Nanomaterials

OpenAIRE

Loeve , Sacha

2017-01-01

International audience; The carbons known today as fullerenes, nanotubes, and graphene were all observed or theo-rized well before becoming emblematic nanomaterials. However, by the 1990s, their mode of existence was shifted from bench or brand objects to technoscientific objects. After focusing on the separate life-stories of these carbons, this chapter recounts how, by eventually interweaving their trajectories and mutually referring to each other, these objects have reborn as a family of l...

Synthesis of Carbon Nanomaterials from Rice Husk via Microwave Oven

Directory of Open Access Journals (Sweden)

Muhammad Asnawi

2018-01-01

Full Text Available Microwave oven was utilized to fabricate carbon nanostructure, specifically CNTs, from waste RH powders. It has been shown that the use of carbon source, catalyst, and commercial microwave oven to induce plasma is necessary to carry on this synthesis. The plasma enhances and speeds up the catalytic decomposition of RH in presence of ferrocene. FESEM, TGA, and Raman spectroscopy were utilized to confirm the presence and quality of produced carbon nanomaterials. In addition, these results suggest the conversion of ferrocene to iron(II, III oxide with notable conversion rate.

High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae

International Nuclear Information System (INIS)

Mesarič, Tina; Gambardella, Chiara; Milivojević, Tamara; Faimali, Marco; Drobne, Damjana; Falugi, Carla; Makovec, Darko; Jemec, Anita; Sepčić, Kristina

2015-01-01

Highlights: • Carbon-based nanomaterials adsorb onto the body surface of A. salina larvae. • Surface adsorption results in concentration–dependent inhibition of larval swimming. • Carbon-based nanomaterials induce no significant mortality of A. salina larvae. - Abstract: We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration–dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5 mg/mL carbon black and 0.1 mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change

High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae

Energy Technology Data Exchange (ETDEWEB)

Mesarič, Tina, E-mail: tina.mesaric84@gmail.com [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Gambardella, Chiara, E-mail: chiara.gambardella@ge.ismar.cnr.it [Institute of Marine Sciences, National Research Council, Genova (Italy); Milivojević, Tamara, E-mail: milivojevictamara@gmail.com [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Faimali, Marco, E-mail: marco.faimali@ismar.cnr.it [Institute of Marine Sciences, National Research Council, Genova (Italy); Drobne, Damjana, E-mail: damjana.drobne@bf.uni-lj.si [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Centre of Excellence in Nanoscience and Nanotechnology (CO Nanocentre), Ljubljana (Slovenia); Centre of Excellence in Advanced Materials and Technologies for the Future (CO NAMASTE), Ljubljana (Slovenia); Falugi, Carla, E-mail: carlafalugi@hotmail.it [Department of Earth, Environment and Life Sciences, University of Genova, Genova (Italy); Makovec, Darko, E-mail: darko.makovec@ijs.si [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Jemec, Anita, E-mail: anita.jemec@bf.uni-lj.si [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia); Sepčić, Kristina, E-mail: kristina.sepcic@bf.uni-lj.si [Department of Biology, Biotechnical Faculty, University of Ljubljana (Slovenia)

2015-06-15

Highlights: • Carbon-based nanomaterials adsorb onto the body surface of A. salina larvae. • Surface adsorption results in concentration–dependent inhibition of larval swimming. • Carbon-based nanomaterials induce no significant mortality of A. salina larvae. - Abstract: We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration–dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5 mg/mL carbon black and 0.1 mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change.

Optical and thermal response of single-walled carbon nanotube–copper sulfide nanoparticle hybrid nanomaterials

International Nuclear Information System (INIS)

Tseng, Yi-Hsuan; He Yuan; Que Long; Lakshmanan, Santana; Yang Chang; Chen Wei

2012-01-01

This paper reports the optical and thermal response of a single-walled carbon nanotube–copper sulfide nanoparticle (SWNT–CuS NP) hybrid nanomaterial and its application as a thermoelectric generator. The hybrid nanomaterial was synthesized using oleylamine molecules as the linker molecules between SWNTs and CuS NPs. Measurements found that the hybrid nanomaterial has significantly increased light absorption (up to 80%) compared to the pure SWNT. Measurements also found that the hybrid nanomaterial thin-film devices exhibit a clear optical and thermal switching effect, which can be further enhanced up to 10 × by asymmetric illumination of light and thermal radiation on the thin-film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials is demonstrated, indicating a new route for achieving thermoelectricity. (paper)

Burners and combustion apparatus for carbon nanomaterial production

Science.gov (United States)

Alford, J. Michael; Diener, Michael D; Nabity, James; Karpuk, Michael

2013-02-05

The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

Preparation of Fe-cored carbon nanomaterials from mountain pine beetle-killed pine wood

Science.gov (United States)

Sung Phil Mun; Zhiyong Cai; Jilei Zhang

2015-01-01

The mountain pine beetle-killed lodgepole pine (Pinus contorta) wood treated with iron (III) nitrate solution was used for the preparation of Fe-cored carbon nanomaterials (Fe-CNs) under various carbonization temperatures. The carbonization yield of Fe-treated sample (5% as Fe) was always 1–3% higher (after ash compensation) than that of the non-...

Nanomaterials in electrochemical biosensors for pesticide detection: advances and challenges in food analysis

International Nuclear Information System (INIS)

Arduini, Fabiana; Moscone, Danila; Cinti, Stefano; Scognamiglio, Viviana

2016-01-01

This overview (with 114 refs.) covers the progress made between 2010 and 2015 in the field of nanomaterial based electrochemical biosensors for pesticides in food. Its main focus is on strategies to analyze real samples. The review first gives a short introduction into the most often used bio recognition elements. These include (a) enzymes (resulting in inhibition-based and direct catalytic biosensors), (b) antibodies (resulting in immunosensors), and (c) aptamers (resulting in aptasensors). The next main section covers the various kinds of nanomaterials for use in biosensors and includes carbonaceous species (carbon nanotubes, graphene, carbon black and others), and non-carbonaceous species in the form of nanoparticles, rods, or porous materials. Aspects of sample treatment and real sample analysis are treated next before discussing vanguard technologies in tailor-made food analysis. (author)

Regulation of catalytic behaviour of hydrolases through interactions with functionalized carbon-based nanomaterials

International Nuclear Information System (INIS)

Pavlidis, Ioannis V.; Vorhaben, Torge; Gournis, Dimitrios; Papadopoulos, George K.; Bornscheuer, Uwe T.; Stamatis, Haralambos

2012-01-01

The interaction of enzymes with carbon-based nanomaterials (CBNs) is crucial for the function of biomolecules and therefore for the design and development of effective nanobiocatalytic systems. In this study, the effect of functionalized CBNs, such as graphene oxide (GO) and multi-wall carbon nanotubes (CNTs), on the catalytic behaviour of various hydrolases of biotechnological interest was monitored and the interactions between CBNs and proteins were investigated. The enzyme–nanomaterial interactions significantly affect the catalytic behaviour of enzymes, resulting in an increase up to 60 % of the catalytic efficiency of lipases and a decrease up to 30 % of the esterase. Moreover, the use of CNTs and GO derivatives, especially those that are amine-functionalized, led to increased thermal stability of most the hydrolases tested. Fluorescence and circular dichroism studies indicated that the altered catalytic behaviour of enzymes in the presence of CBNs arises from specific enzyme–nanomaterial interactions, which can lead to significant conformational changes. In the case of lipases, the conformational changes led to a more active and rigid structure, while in the case of esterases this led to destabilization and unfolding. Kinetic and spectroscopic studies indicated that the extent of the interactions between CBNs and hydrolases can be mainly controlled by the functionalization of nanomaterials than by their geometry.

Regulation of catalytic behaviour of hydrolases through interactions with functionalized carbon-based nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Pavlidis, Ioannis V. [University of Ioannina, Laboratory of Biotechnology, Department of Biological Applications and Technologies (Greece); Vorhaben, Torge [Institute of Biochemistry, Greifswald University, Department of Biotechnology and Enzyme Catalysis (Germany); Gournis, Dimitrios [University of Ioannina, Department of Materials Science and Engineering (Greece); Papadopoulos, George K. [Epirus Institute of Technology, Laboratory of Biochemistry and Biophysics, Faculty of Agricultural Technology (Greece); Bornscheuer, Uwe T. [Institute of Biochemistry, Greifswald University, Department of Biotechnology and Enzyme Catalysis (Germany); Stamatis, Haralambos, E-mail: hstamati@cc.uoi.gr [University of Ioannina, Laboratory of Biotechnology, Department of Biological Applications and Technologies (Greece)

2012-05-15

The interaction of enzymes with carbon-based nanomaterials (CBNs) is crucial for the function of biomolecules and therefore for the design and development of effective nanobiocatalytic systems. In this study, the effect of functionalized CBNs, such as graphene oxide (GO) and multi-wall carbon nanotubes (CNTs), on the catalytic behaviour of various hydrolases of biotechnological interest was monitored and the interactions between CBNs and proteins were investigated. The enzyme-nanomaterial interactions significantly affect the catalytic behaviour of enzymes, resulting in an increase up to 60 % of the catalytic efficiency of lipases and a decrease up to 30 % of the esterase. Moreover, the use of CNTs and GO derivatives, especially those that are amine-functionalized, led to increased thermal stability of most the hydrolases tested. Fluorescence and circular dichroism studies indicated that the altered catalytic behaviour of enzymes in the presence of CBNs arises from specific enzyme-nanomaterial interactions, which can lead to significant conformational changes. In the case of lipases, the conformational changes led to a more active and rigid structure, while in the case of esterases this led to destabilization and unfolding. Kinetic and spectroscopic studies indicated that the extent of the interactions between CBNs and hydrolases can be mainly controlled by the functionalization of nanomaterials than by their geometry.

Redox-responsive theranostic nanoplatforms based on inorganic nanomaterials.

Science.gov (United States)

Han, Lu; Zhang, Xiao-Yong; Wang, Yu-Long; Li, Xi; Yang, Xiao-Hong; Huang, Min; Hu, Kun; Li, Lu-Hai; Wei, Yen

2017-08-10

Spurred on by advances in materials chemistry and nanotechnology, scientists have developed many novel nanopreparations for cancer diagnosis and therapy. To treat complex malignant tumors effectively, multifunctional nanomedicines with targeting ability, imaging properties and controlled drug release behavior should be designed and exploited. The therapeutic efficiency of loaded drugs can be dramatically improved using redox-responsive nanoplatforms which can sense the differences in the redox status of tumor tissues and healthy ones. Redox-sensitive nanocarriers can be constructed from both organic and inorganic nanomaterials; however, at present, drug delivery nanovectors progressively lean towards inorganic nanomaterials because of their facile synthesis/modification and their unique physicochemical properties. In this review, we focus specifically on the preparation and application of redox-sensitive nanosystems based on mesoporous silica nanoparticles (MSNs), carbon nanomaterials, magnetic nanoparticles, gold nanomaterials and other inorganic nanomaterials. We discuss relevant examples of redox-sensitive nanosystems in each category. Finally, we discuss current challenges and future strategies from the aspect of material design and practical application. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential thermodynamic signature of carbon nanomaterials using amphiphilic micellar probe

Science.gov (United States)

Bhattacharyya, Tamoghna; Dasgupta, Anjan Kr

2018-04-01

The thermodynamic signature of single-wall carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs) and reduced graphene oxide (rG-O) using amphiphilic micellar probe has been explored. The study reveals an intricate correlation between nano-surface topology and calorimetric profile of SWCNTs, MWCNTs and rG-O. The critical micelle concentration (CMC) is found to be sensitive to the topological diversity of nanomaterials. The study explores a thermodynamic approach to characterize the nano-surface topology of SWCNTs, MWCNTs and graphene surface.

Nanoscale Interactions between Engineered Nanomaterials and Black Carbon (Biochar) in Soil

Science.gov (United States)

An understanding of the interactions between engineered nanomaterials (NMs) and soil constituents, and a comprehension of how these interactions may affect biological uptake and toxicity are currently lacking. Charcoal black carbon is a normal constituent of soils due to fire history, and can be pre...

2D nanomaterials based electrochemical biosensors for cancer diagnosis.

Science.gov (United States)

Wang, Lu; Xiong, Qirong; Xiao, Fei; Duan, Hongwei

2017-03-15

Cancer is a leading cause of death in the world. Increasing evidence has demonstrated that early diagnosis holds the key towards effective treatment outcome. Cancer biomarkers are extensively used in oncology for cancer diagnosis and prognosis. Electrochemical sensors play key roles in current laboratory and clinical analysis of diverse chemical and biological targets. Recent development of functional nanomaterials offers new possibilities of improving the performance of electrochemical sensors. In particular, 2D nanomaterials have stimulated intense research due to their unique array of structural and chemical properties. The 2D materials of interest cover broadly across graphene, graphene derivatives (i.e., graphene oxide and reduced graphene oxide), and graphene-like nanomaterials (i.e., 2D layered transition metal dichalcogenides, graphite carbon nitride and boron nitride nanomaterials). In this review, we summarize recent advances in the synthesis of 2D nanomaterials and their applications in electrochemical biosensing of cancer biomarkers (nucleic acids, proteins and some small molecules), and present a personal perspective on the future direction of this area. Copyright © 2016 Elsevier B.V. All rights reserved.

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

Directory of Open Access Journals (Sweden)

Toma Susi

2015-01-01

Full Text Available X-ray photoelectron spectroscopy (XPS is one of the best tools for studying the chemical modification of surfaces, and in particular the distribution and bonding of heteroatom dopants in carbon nanomaterials such as graphene and carbon nanotubes. Although these materials have superb intrinsic properties, these often need to be modified in a controlled way for specific applications. Towards this aim, the most studied dopants are neighbors to carbon in the periodic table, nitrogen and boron, with phosphorus starting to emerge as an interesting new alternative. Hundreds of studies have used XPS for analyzing the concentration and bonding of dopants in various materials. Although the majority of works has concentrated on nitrogen, important work is still ongoing to identify its precise atomic bonding configurations. In general, care should be taken in the preparation of a suitable sample, consideration of the intrinsic photoemission response of the material in question, and the appropriate spectral analysis. If this is not the case, incorrect conclusions can easily be drawn, especially in the assignment of measured binding energies into specific atomic configurations. Starting from the characteristics of pristine materials, this review provides a practical guide for interpreting X-ray photoelectron spectra of doped graphitic carbon nanomaterials, and a reference for their binding energies that are vital for compositional analysis via XPS.

Microscopic Fuel Particles Produced by Self-Assembly of Actinide Nanoclusters on Carbon Nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Na, Chongzheng [Univ. of Notre Dame, IN (United States)

2016-10-17

Many consider further development of nuclear power to be essential for sustained development of society; however, the fuel forms currently used are expensive to recycle. In this project, we sought to create the knowledge and knowhow that are needed to produce nanocomposite materials by directly depositing uranium nanoclusters on networks of carbon-­ based nanomaterials. The objectives of the proposed work were to (1) determine the control of uranium nanocluster surface chemistry on nanocomposite formation, (2) determine the control of carbon nanomaterial surface chemistry on nanocomposite formation, and (3) develop protocols for synthesizing uranium-­carbon nanomaterials. After examining a wide variety of synthetic methods, we show that synthesizing graphene-­supported UO₂ nanocrystals in polar ethylene glycol compounds by polyol reduction under boiling reflux can enable the use of an inexpensive graphene precursor graphene oxide in the production of uranium-carbon nanocomposites in a one-­pot process. We further show that triethylene glycol is the most suitable solvent for producing nanometer-­sized UO₂ crystals compared to monoethylene glycol, diethylene glycol, and polyethylene glycol. Graphene-­supported UO₂ nanocrystals synthesized with triethylene glycol show evidence of heteroepitaxy, which can be beneficial for facilitating heat transfer in nuclear fuel particles. Furthermore, we show that graphene-supported UO₂ nanocrystals synthesized by polyol reduction can be readily stored in alcohols, preventing oxidation from the prevalent oxygen in air. Together, these methods provide a facile approach for preparing and storing graphene-supported UO nanocrystals for further investigation and development under ambient conditions.

Mesoporous carbon incorporated metal oxide nanomaterials as supercapacitor electrodes

Energy Technology Data Exchange (ETDEWEB)

Jiang, Hao [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Ma, Jan [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Li, Chunzhong [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

2012-08-08

Supercapacitors have attracted huge attention in recent years as they have the potential to satisfy the demand of both huge energy and power density in many advanced technologies. However, poor conductivity and cycling stability remains to be the major challenge for its widespread application. Various strategies have been developed for meeting the ever-increasing energy and power demands in supercapacitors. This Research News article aims to review recent progress in the development of mesoporous carbon incorporated metal oxide nanomaterials, especially metal oxide nanoparticles confined in ordered mesoporous carbon and 1D metal oxides coated with a layer of mesoporous carbon for high-performance supercapacitor applications. In addition, a recent trend in supercapacitor development - hierarchical porous graphitic carbons (HPGC) combining macroporous cores, mesoporous walls, and micropores as an excellent support for metal oxides - is also discussed. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Graphene, carbon nanotubes, zinc oxide and gold as elite nanomaterials for fabrication of biosensors for healthcare.

Science.gov (United States)

Kumar, Sandeep; Ahlawat, Wandit; Kumar, Rajesh; Dilbaghi, Neeraj

2015-08-15

Technological advancements worldwide at rapid pace in the area of materials science and nanotechnology have made it possible to synthesize nanoparticles with desirable properties not exhibited by the bulk material. Among variety of available nanomaterials, graphene, carbon nanotubes, zinc oxide and gold nanopartilces proved to be elite and offered amazing electrochemical biosensing. This encourages us to write a review which highlights the recent achievements in the construction of genosensor, immunosensor and enzymatic biosensor based on the above nanomaterials. Carbon based nanomaterials offers a direct electron transfer between the functionalized nanomaterials and active site of bioreceptor without involvement of any mediator which not only amplifies the signal but also provide label free sensing. Gold shows affinity towards immunological molecules and is most routinely used for immunological sensing. Zinc oxide can easily immobilize proteins and hence offers a large group of enzyme based biosensor. Modification of the working electrode by introduction of these nanomaterials or combination of two/three of above nanomaterials together and forming a nanocomposite reflected the best results with excellent stability, reproducibility and enhanced sensitivity. Highly attractive electrochemical properties and electrocatalytic activity of these elite nanomaterials have facilitated achievement of enhanced signal amplification needed for the construction of ultrasensitive electrochemical affinity biosensors for detection of glucose, cholesterol, Escherichia coli, influenza virus, cancer, human papillomavirus, dopamine, glutamic acid, IgG, IgE, uric acid, ascorbic acid, acetlycholine, cortisol, cytosome, sequence specific DNA and amino acids. Recent researches for bedside biosensors are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Biomedical nanomaterials from design to implementation

CERN Document Server

Webster, Thomas

2016-01-01

Biomedical Nanomaterials brings together the engineering applications and challenges of using nanostructured surfaces and nanomaterials in healthcare in a single source. Each chapter covers important and new information in the biomedical applications of nanomaterials.

Synthesis and Characterization of Three Dimensional Nanostructures Based on Interconnected Carbon Nanomaterials

Science.gov (United States)

Koizumi, Ryota

This thesis addresses various types of synthetic methods for novel three dimensional nanomaterials and nanostructures based on interconnected carbon nanomaterials using solution chemistry and chemical vapor deposition (CVD) methods. Carbon nanotube (CNT) spheres with porous and scaffold structures consisting of interconnected CNTs were synthesized by solution chemistry followed by freeze-drying, which have high elasticity under nano-indentation tests. This allows the CNT spheres to be potentially applied to mechanical dampers. CNTs were also grown on two dimensional materials--such as reduced graphene oxide (rGO) and hexagonal boron nitride (h-BN)--by CVD methods, which are chemically interconnected. CNTs on rGO and h-BN interconnected structures performed well as electrodes for supercapacitors. Furthermore, unique interconnected flake structures of alpha-phase molybdenum carbide were developed by a CVD method. The molybdenum carbide can be used for a catalyst of hydrogen evolution reaction activity as well as an electrode for supercapacitors.

Synthesis and applications of carbon nanomaterials for energy generation and storage.

Science.gov (United States)

Notarianni, Marco; Liu, Jinzhang; Vernon, Kristy; Motta, Nunzio

2016-01-01

The world is facing an energy crisis due to exponential population growth and limited availability of fossil fuels. Over the last 20 years, carbon, one of the most abundant materials found on earth, and its allotrope forms such as fullerenes, carbon nanotubes and graphene have been proposed as sources of energy generation and storage because of their extraordinary properties and ease of production. Various approaches for the synthesis and incorporation of carbon nanomaterials in organic photovoltaics and supercapacitors have been reviewed and discussed in this work, highlighting their benefits as compared to other materials commonly used in these devices. The use of fullerenes, carbon nanotubes and graphene in organic photovoltaics and supercapacitors is described in detail, explaining how their remarkable properties can enhance the efficiency of solar cells and energy storage in supercapacitors. Fullerenes, carbon nanotubes and graphene have all been included in solar cells with interesting results, although a number of problems are still to be overcome in order to achieve high efficiency and stability. However, the flexibility and the low cost of these materials provide the opportunity for many applications such as wearable and disposable electronics or mobile charging. The application of carbon nanotubes and graphene to supercapacitors is also discussed and reviewed in this work. Carbon nanotubes, in combination with graphene, can create a more porous film with extraordinary capacitive performance, paving the way to many practical applications from mobile phones to electric cars. In conclusion, we show that carbon nanomaterials, developed by inexpensive synthesis and process methods such as printing and roll-to-roll techniques, are ideal for the development of flexible devices for energy generation and storage - the key to the portable electronics of the future.

Synthesis and applications of carbon nanomaterials for energy generation and storage

Directory of Open Access Journals (Sweden)

Marco Notarianni

2016-02-01

Full Text Available The world is facing an energy crisis due to exponential population growth and limited availability of fossil fuels. Over the last 20 years, carbon, one of the most abundant materials found on earth, and its allotrope forms such as fullerenes, carbon nanotubes and graphene have been proposed as sources of energy generation and storage because of their extraordinary properties and ease of production. Various approaches for the synthesis and incorporation of carbon nanomaterials in organic photovoltaics and supercapacitors have been reviewed and discussed in this work, highlighting their benefits as compared to other materials commonly used in these devices. The use of fullerenes, carbon nanotubes and graphene in organic photovoltaics and supercapacitors is described in detail, explaining how their remarkable properties can enhance the efficiency of solar cells and energy storage in supercapacitors. Fullerenes, carbon nanotubes and graphene have all been included in solar cells with interesting results, although a number of problems are still to be overcome in order to achieve high efficiency and stability. However, the flexibility and the low cost of these materials provide the opportunity for many applications such as wearable and disposable electronics or mobile charging. The application of carbon nanotubes and graphene to supercapacitors is also discussed and reviewed in this work. Carbon nanotubes, in combination with graphene, can create a more porous film with extraordinary capacitive performance, paving the way to many practical applications from mobile phones to electric cars. In conclusion, we show that carbon nanomaterials, developed by inexpensive synthesis and process methods such as printing and roll-to-roll techniques, are ideal for the development of flexible devices for energy generation and storage – the key to the portable electronics of the future.

Carbon-nanotube-based liquids: a new class of nanomaterials and their applications

International Nuclear Information System (INIS)

Phan, Ngoc Minh; Nguyen, Manh Hong; Phan, Hong Khoi; Bui, Hung Thang

2014-01-01

Carbon-nanotube-based liquids—a new class of nanomaterials—have shown many interesting properties and distinctive features offering unprecedented potential for many applications. This paper summarizes the recent progress on the study of the preparation, characterization and properties of carbon-nanotube-based liquids including so-called nanofluids, nanolubricants and different kinds of nanosolutions containing multi-walled carbon nanotubes/single-walled carbon nanotubes/graphene. A broad range of current and future applications of these nanomaterials in the fields of energy saving, power electronic and optoelectronic devices, biotechnology and agriculture are presented. The paper also identifies challenges and opportunities for future research. (paper)

Nanomaterials-based electrochemical sensors for nitric oxide

International Nuclear Information System (INIS)

Dang, Xueping; Hu, Hui; Wang, Shengfu; Hu, Shengshui

2015-01-01

Electrochemical sensing has been demonstrated to represent an efficient way to quantify nitric oxide (NO) in challenging physiological environments. A sensing interface based on nanomaterials opens up new opportunities and broader prospects for electrochemical NO sensors. This review (with 141 refs.) gives a general view of recent advances in the development of electrochemical sensors based on nanomaterials. It is subdivided into sections on (i) carbon derived nanomaterials (such as carbon nanotubes, graphenes, fullerenes), (ii) metal nanoparticles (including gold, platinum and other metallic nanoparticles); (iii) semiconductor metal oxide nanomaterials (including the oxides of titanium, aluminum, iron, and ruthenium); and finally (iv) nanocomposites (such as those formed from carbon nanomaterials with nanoparticles of gold, platinum, NiO or TiO 2 ). The various strategies are discussed, and the advances of using nanomaterials and the trends in NO sensor technology are outlooked in the final section. (author)

High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae.

Science.gov (United States)

Mesarič, Tina; Gambardella, Chiara; Milivojević, Tamara; Faimali, Marco; Drobne, Damjana; Falugi, Carla; Makovec, Darko; Jemec, Anita; Sepčić, Kristina

2015-06-01

We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration-dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5mg/mL carbon black and 0.1mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6 mg/mL, and more than 90% mortality at 0.7 mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and Application of Graphene Based Nanomaterials

Science.gov (United States)

Peng, Zhiwei

Graphene, a two-dimensional sp2-bonded carbon material, has recently attracted major attention due to its excellent electrical, optical and mechanical properties. Depending on different applications, graphene and its derived hybrid nanomaterials can be synthesized by either bottom-up chemical vapor deposition (CVD) methods for electronics, or various top-down chemical reaction methods for energy generation and storage devices. My thesis begins with the investigation of CVD synthesis of graphene thin films in Chapter 1, including the direct growth of bilayer graphene on insulating substrates and synthesis of "rebar graphene": a hybrid structure with graphene and carbon or boron nitride nanotubes. Chapter 2 discusses the synthesis of nanoribbon-shaped materials and their applications, including splitting of vertically aligned multi-walled carbon nanotube carpets for supercapacitors, synthesis of dispersable ferromagnetic graphene nanoribbon stacks with enhanced electrical percolation properties in magnetic field, graphene nanoribbon/SnO 2 nanocomposite for lithium ion batteries, and enhanced electrocatalysis for hydrogen evolution reactions from WS2 nanoribbons. Next, Chapter 3 discusses graphene coated iron oxide nanomaterials and their use in energy storage applications. Finally, Chapter 4 introduces the development, characterization, and fabrication of laser induced graphene and its application as supercapacitors.

Carbon-Based Nanomaterials/Allotropes: A Glimpse of Their Synthesis, Properties and Some Applications

Science.gov (United States)

Zainal, Zulkarnain; Yusof, Nor Azah

2018-01-01

Carbon in its single entity and various forms has been used in technology and human life for many centuries. Since prehistoric times, carbon-based materials such as graphite, charcoal and carbon black have been used as writing and drawing materials. In the past two and a half decades or so, conjugated carbon nanomaterials, especially carbon nanotubes, fullerenes, activated carbon and graphite have been used as energy materials due to their exclusive properties. Due to their outstanding chemical, mechanical, electrical and thermal properties, carbon nanostructures have recently found application in many diverse areas; including drug delivery, electronics, composite materials, sensors, field emission devices, energy storage and conversion, etc. Following the global energy outlook, it is forecasted that the world energy demand will double by 2050. This calls for a new and efficient means to double the energy supply in order to meet the challenges that forge ahead. Carbon nanomaterials are believed to be appropriate and promising (when used as energy materials) to cushion the threat. Consequently, the amazing properties of these materials and greatest potentials towards greener and environment friendly synthesis methods and industrial scale production of carbon nanostructured materials is undoubtedly necessary and can therefore be glimpsed as the focal point of many researchers in science and technology in the 21st century. This is based on the incredible future that lies ahead with these smart carbon-based materials. This review is determined to give a synopsis of new advances towards their synthesis, properties, and some applications as reported in the existing literatures. PMID:29438327

Carbon-Based Nanomaterials/Allotropes: A Glimpse of Their Synthesis, Properties and Some Applications

Directory of Open Access Journals (Sweden)

Salisu Nasir

2018-02-01

Full Text Available Carbon in its single entity and various forms has been used in technology and human life for many centuries. Since prehistoric times, carbon-based materials such as graphite, charcoal and carbon black have been used as writing and drawing materials. In the past two and a half decades or so, conjugated carbon nanomaterials, especially carbon nanotubes, fullerenes, activated carbon and graphite have been used as energy materials due to their exclusive properties. Due to their outstanding chemical, mechanical, electrical and thermal properties, carbon nanostructures have recently found application in many diverse areas; including drug delivery, electronics, composite materials, sensors, field emission devices, energy storage and conversion, etc. Following the global energy outlook, it is forecasted that the world energy demand will double by 2050. This calls for a new and efficient means to double the energy supply in order to meet the challenges that forge ahead. Carbon nanomaterials are believed to be appropriate and promising (when used as energy materials to cushion the threat. Consequently, the amazing properties of these materials and greatest potentials towards greener and environment friendly synthesis methods and industrial scale production of carbon nanostructured materials is undoubtedly necessary and can therefore be glimpsed as the focal point of many researchers in science and technology in the 21st century. This is based on the incredible future that lies ahead with these smart carbon-based materials. This review is determined to give a synopsis of new advances towards their synthesis, properties, and some applications as reported in the existing literatures.

Environmental effects of engineered nanomaterials

DEFF Research Database (Denmark)

Lützhøft, Hans-Christian Holten; Hartmann, Nanna B.; Brinch, Anna

This report presents ecotoxicological data and Predicted No-Effect Concentrations (PNECs) for nine selected nanomaterials which are considered to be environmentally relevant due to high usage or how they are used. These data will together with data from other reports/projects be used in an overall...... assessment of the environmental risk of nanomaterials in Denmark. The nine investigated nanomaterials are: Titanium Dioxide, Zinc Oxide, Silver, Carbon Nanotubes, Copper Oxide, Nano Zero Valent Iron, Cerium Dioxide, Quantum Dots and Carbon Black. To support the assessment of the data found in the peer...

Porous substrates filled with nanomaterials

Science.gov (United States)

Worsley, Marcus A.; Baumann, Theodore F.; Satcher, Jr., Joe H.; Stadermann, Michael

2018-04-03

A composition comprising: at least one porous carbon monolith, such as a carbon aerogel, comprising internal pores, and at least one nanomaterial, such as carbon nanotubes, disposed uniformly throughout the internal pores. The nanomaterial can be disposed in the middle of the monolith. In addition, a method for making a monolithic solid with both high surface area and good bulk electrical conductivity is provided. A porous substrate having a thickness of 100 microns or more and comprising macropores throughout its thickness is prepared. At least one catalyst is deposited inside the porous substrate. Subsequently, chemical vapor deposition is used to uniformly deposit a nanomaterial in the macropores throughout the thickness of the porous substrate. Applications include electrical energy storage, such as batteries and capacitors, and hydrogen storage.

Effect of the Addition of Carbon Nanomaterials on Electrical and Mechanical Properties of Wood Plastic Composites

Directory of Open Access Journals (Sweden)

Xingli Zhang

2017-11-01

Full Text Available Wood Plastic Composites (WPCs are a new generation of green composites that could optimize the use of harvested trees and increase the entire value chain. In this study, the electrical and mechanical properties of WPCs containing carbon blacks (CB, flake graphite (FG and carbon nanotubes (CNTs have been investigated. The electrical property of WPCs is improved significantly owing to the introduction of these carbon nanomaterial fillers. The volume and surface resistivity values of the investigated composites all obviously decreased with the increase in filler content, especially CNTs, which displayed the most satisfactory results. Based on a series of laboratory experiments carried out to investigate the mechanical performance, it can be concluded that the addition of the carbon nanomaterial fillers decreases the mechanical properties of WPCs slightly with the increase in filler content because of the weak interfacial interactions between the fillers and polymer matrix.

Fascinating Magnetic Energy Storage Nanomaterials: A Brief Review.

Science.gov (United States)

Sreenivasulu, Kummari V; Srikanth, Vadali V S S

2017-07-10

In this brief review, the importance of nanotechnology in developing novel magnetic energy storage materials is discussed. The discussion covers recent patents on permanent magnetic materials and especially covers processing of permanent magnets (rare-earth and rare-earth free magnets), importance of rare-earth permanent magnets and necessity of rare-earth free permanent magnets. Magnetic energy storage materials are those magnetic materials which exhibit very high energy product (BH)max (where B is the magnetic induction in Gauss (G) whereas H is the applied magnetic field in Oersted (Oe)). (BH)max is the direct measure of the ability of a magnetic material to store energy. In this context, processing of magnetic energy storage composite materials constituted by soft and hard magnetic materials played a predominant role in achieving high (BH)max values due to the exchange coupling phenomenon between the soft and hard magnetic phases within the composite. Magnetic energy storage composites are normally composed of rare-earth magnetic materials as well as rare-earth free magnetic materials. Nanotechnology's influence on the enhancement of energy product due to the exchange coupling phenomenon is of great prominence and therefore discussed in this review. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Photocatalytic composites based on titania nanoparticles and carbon nanomaterials

International Nuclear Information System (INIS)

Nguyen, Bich Ha; Nguyen, Van Hieu; Vu, Dinh Lam

2015-01-01

In this article we present a review on recent experimental works toward the formation of visible light responsive composite photocatalysts on the basis of titania nanoparticles and carbon nanomaterials of different types. The research results achieved in last years has shown that the nanocomposite photocatalysts comprising titania nanoparticles and graphene or graphene oxide sheets, and also nanoparticles of noble metals and metallic oxides, exhibited the evident priority compared to the others. Therefore our review emphasizes the research on these promising visible light responsive nanophotocatalysts. (review)

Carbon nanomaterials as counter electrodes for dye solar cells

Energy Technology Data Exchange (ETDEWEB)

Aitola, K.

2012-05-15

The dye solar cell (DSC) is an interesting emerging technology for photovoltaic conversion of solar electromagnetic energy to electrical energy. The DSC is based mainly on cheap starting materials and it can be manufactured by roll-to-roll deposition techniques on flexible substrates, which is considered as one option for cost-effective large-scale solar cell production. The most expensive component of the DSC is the transparent conductive oxide glass substrate, and considerable cost reductions can be achieved by changing it to e.g. a plastic substrate. Plastic substrates are very flexible, lightweight and transparent. The state of the art DSC catalyst is thermally deposited or sputtered platinum, but platinum is a rare and expensive metal. Carbon, on the other hand, is widely available and some of its nanomaterials conduct electricity and are catalytic toward the DSC counter electrode (CE) reduction reaction. In this work, carbon nanomaterials and their composites were studied as the DSC CE active material. The materials were random network single-walled carbon nanotube (SWCNT) film on glass and plastic substrate, vertically aligned multiwalled carbon nanotube 'forest' film on steel and quartz substrate and carbon nanoparticle composite film on indium tin oxidepolyethylene terephthalate (ITO-PET) substrate. After comparison of the materials, the SWCNT network film on PET was chosen as the main CE type of this study, since it offers superior conductivity, transparency and flexibility over the other carbon-based CEs, it is also the thinnest and contains only one active material component. When a 30 % transparent SWCNT network film on PET was tested as a DSC CE, it was found out that such a film is not catalytic and conductive enough for a full 1 sun illumination DSC device, but the film could be suitable for a indoor illumination level application. The catalytic properties of a 10 % transparent SWCNT film were improved by depositing conductive PEDOT

Carbon-based smart nanomaterials in biomedicine and neuroengineering

Directory of Open Access Journals (Sweden)

Antonina M. Monaco

2014-10-01

Full Text Available The search for advanced biomimetic materials that are capable of offering a scaffold for biological tissues during regeneration or of electrically connecting artificial devices with cellular structures to restore damaged brain functions is at the forefront of interdisciplinary research in materials science. Bioactive nanoparticles for drug delivery, substrates for nerve regeneration and active guidance, as well as supramolecular architectures mimicking the extracellular environment to reduce inflammatory responses in brain implants, are within reach thanks to the advancements in nanotechnology. In particular, carbon-based nanostructured materials, such as graphene, carbon nanotubes (CNTs and nanodiamonds (NDs, have demonstrated to be highly promising materials for designing and fabricating nanoelectrodes and substrates for cell growth, by virtue of their peerless optical, electrical, thermal, and mechanical properties. In this review we discuss the state-of-the-art in the applications of nanomaterials in biological and biomedical fields, with a particular emphasis on neuroengineering.

Chemosensitizing effects of carbon-based nanomaterials in cancer cells: enhanced apoptosis and inhibition of proliferation as underlying mechanisms

International Nuclear Information System (INIS)

Erdmann, Kati; Ringel, Jessica; Rieger, Christiane; Huebner, Doreen; Wirth, Manfred P; Fuessel, Susanne; Hampel, Silke

2014-01-01

Recent studies have shown that carbon nanomaterials such as carbon nanofibres (CNFs) and multi-walled carbon nanotubes (CNTs) can exert antitumor activities themselves and sensitize cancer cells to conventional chemotherapeutics such as carboplatin and cisplatin. In the present study, the chemosensitizing effect of CNFs and CNTs on cancer cells of urological origin was investigated regarding the underlying mechanisms. Prostate cancer (DU-145, PC-3) and bladder cancer (EJ28) cells were treated with carbon nanomaterials (CNFs, CNTs) and chemotherapeutics (carboplatin, cisplatin) alone as well as in combination for 24 h. Forty-eight (EJ28) or 72 h (DU-145, PC-3) after the end of treatment the effects on cellular proliferation, clonogenic survival, cell death rate and cell cycle distribution were evaluated. Depending on the cell line, simultaneous administration of chemotherapeutics and carbon nanomaterials produced an additional inhibition of cellular proliferation and clonogenic survival of up to 77% and 98%, respectively, compared to the inhibitory effects of the chemotherapeutics alone. These strongly enhanced antiproliferative effects were accompanied by an elevated cell death rate, which was predominantly mediated via apoptosis and not by necrosis. The antitumor effects of combinations with CNTs were less pronounced than those with CNFs. The enhanced effects of the combinatory treatments on cellular function were mostly of additive to partly synergistic nature. Furthermore, cell cycle analysis demonstrated an arrest at the G2/M phase mediated by a monotreatment with chemotherapeutics. Following combinatory treatments, mostly less than or nearly additive increases of cell fractions in the G2/M phase could be observed. In conclusion, the pronounced chemosensitizing effects of CNFs and CNTs were mediated by an enhanced apoptosis and inhibition of proliferation. The combination of carbon-based nanomaterials and conventional chemotherapeutics represents a novel

Chemosensitizing effects of carbon-based nanomaterials in cancer cells: enhanced apoptosis and inhibition of proliferation as underlying mechanisms

Science.gov (United States)

Erdmann, Kati; Ringel, Jessica; Hampel, Silke; Rieger, Christiane; Huebner, Doreen; Wirth, Manfred P.; Fuessel, Susanne

2014-10-01

Recent studies have shown that carbon nanomaterials such as carbon nanofibres (CNFs) and multi-walled carbon nanotubes (CNTs) can exert antitumor activities themselves and sensitize cancer cells to conventional chemotherapeutics such as carboplatin and cisplatin. In the present study, the chemosensitizing effect of CNFs and CNTs on cancer cells of urological origin was investigated regarding the underlying mechanisms. Prostate cancer (DU-145, PC-3) and bladder cancer (EJ28) cells were treated with carbon nanomaterials (CNFs, CNTs) and chemotherapeutics (carboplatin, cisplatin) alone as well as in combination for 24 h. Forty-eight (EJ28) or 72 h (DU-145, PC-3) after the end of treatment the effects on cellular proliferation, clonogenic survival, cell death rate and cell cycle distribution were evaluated. Depending on the cell line, simultaneous administration of chemotherapeutics and carbon nanomaterials produced an additional inhibition of cellular proliferation and clonogenic survival of up to 77% and 98%, respectively, compared to the inhibitory effects of the chemotherapeutics alone. These strongly enhanced antiproliferative effects were accompanied by an elevated cell death rate, which was predominantly mediated via apoptosis and not by necrosis. The antitumor effects of combinations with CNTs were less pronounced than those with CNFs. The enhanced effects of the combinatory treatments on cellular function were mostly of additive to partly synergistic nature. Furthermore, cell cycle analysis demonstrated an arrest at the G2/M phase mediated by a monotreatment with chemotherapeutics. Following combinatory treatments, mostly less than or nearly additive increases of cell fractions in the G2/M phase could be observed. In conclusion, the pronounced chemosensitizing effects of CNFs and CNTs were mediated by an enhanced apoptosis and inhibition of proliferation. The combination of carbon-based nanomaterials and conventional chemotherapeutics represents a novel

Carbon Nanomaterials for Detection, Assessment and Purification of Oil and Natural Gas

Science.gov (United States)

Hwang, Chih-Chau

This thesis studies several carbon nanomaterials. Their synthesis and characterization are studied as well as their potential applications to the oil industry. The carbon nanomaterials studied here include mesoporous carbon (CMK-3), sulfur- or nitrogen-doped porous carbon (SPC or NPC), and commercial carbon black (CB). Through appropriate functionalization, these carbon nanomaterials exhibit unique properties and their performances in detection, assessment as well as purification of oil and natural gas are studied and demonstrated. First, it was shown that amine-modified CMK-3 composites, polyethylenimine-CMK-3 (PEI-CMK-3) and polyvinylamine-CMK-3 (PVA-CMK-3) can be synthesized through in situ polymerization of amine species within the channels of the CMK-3. The synthesis process results in the entrapped amine polymers interpenetrating the composite frameworks of the CMK-3, improving the CO2 capture performance and recycle stability. CO2 uptake by the synthesized composites was determined using a gravimetric method at 30°C and 1 atm; the 39% PEI-CMK-3 composite had ˜12 wt% (3.1 mmol/g) CO2 uptake capacity and the 37% PVA-CMK-3 composite had ˜13 wt% (3.5 mmol/g) CO 2 uptake capacity. A desorption temperature of 75°C was sufficient for regeneration. The CO2 uptake was the same when using 10% CO 2 in a 90% CH4, C2H6 and C3H 8 mixture, underscoring this composite's efficacy for CO 2 sequestration from natural gas. Secondly, nucleophilic porous carbons (SPC and NPC) were synthesized from simple and inexpensive carbon-sulfur and carbon-nitrogen precursors. A strong sorbate-sorbent interaction between CO2 and nucleophilic centers in the porous carbon was established using spectroscopic and heat of sorption data. Raman spectroscopy supports the assertion that the nucleophilic centers react with the CO2 to produce carbonate anions that further cause polymerization in the porous carbon channels to form poly(CO2) under much lower pressure than previously reported for such

Organic nanomaterials: synthesis, characterization, and device applications

CERN Document Server

Torres, Tomas

2013-01-01

Recent developments in nanoscience and nanotechnology have given rise to a new generation of functional organic nanomaterials with controlled morphology and well-defined properties, which enable a broad range of useful applications. This book explores some of the most important of these organic nanomaterials, describing how they are synthesized and characterized. Moreover, the book explains how researchers have incorporated organic nanomaterials into devices for real-world applications.Featuring contributions from an international team of leading nanoscientists, Organic Nanomaterials is divided into five parts:Part One introduces the fundamentals of nanomaterials and self-assembled nanostructuresPart Two examines carbon nanostructures—from fullerenes to carbon nanotubes to graphene—reporting on properties, theoretical studies, and applicationsPart Three investigates key aspects of some inorganic materials, self-assembled monolayers,...

Mesoporous carbon nanomaterials induced pulmonary surfactant inhibition, cytotoxicity, inflammation and lung fibrosis.

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Chen, Yunan; Yang, Yi; Xu, Bolong; Wang, Shunhao; Li, Bin; Ma, Juan; Gao, Jie; Zuo, Yi Y; Liu, Sijin

2017-12-01

Environmental exposure and health risk upon engineered nanomaterials are increasingly concerned. The family of mesoporous carbon nanomaterials (MCNs) is a rising star in nanotechnology for multidisciplinary research with versatile applications in electronics, energy and gas storage, and biomedicine. Meanwhile, there is mounting concern on their environmental health risks due to the growing production and usage of MCNs. The lung is the primary site for particle invasion under environmental exposure to nanomaterials. Here, we studied the comprehensive toxicological profile of MCNs in the lung under the scenario of moderate environmental exposure. It was found that at a low concentration of 10μg/mL MCNs induced biophysical inhibition of natural pulmonary surfactant. Moreover, MCNs at similar concentrations reduced viability of J774A.1 macrophages and lung epithelial A549 cells. Incubating with nature pulmonary surfactant effectively reduced the cytotoxicity of MCNs. Regarding the pro-inflammatory responses, MCNs activated macrophages in vitro, and stimulated lung inflammation in mice after inhalation exposure, associated with lung fibrosis. Moreover, we found that the size of MCNs played a significant role in regulating cytotoxicity and pro-inflammatory potential of this nanomaterial. In general, larger MCNs induced more pronounced cytotoxic and pro-inflammatory effects than their smaller counterparts. Our results provided valuable information on the toxicological profile and environmental health risks of MCNs, and suggested that fine-tuning the size of MCNs could be a practical precautionary design strategy to increase safety and biocompatibility of this nanomaterial. Copyright © 2017. Published by Elsevier B.V.

Determination of puerarin in rat plasma using PEGylated magnetic carbon nanotubes by high performance liquid chromatography.

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Yu, Panfeng; Wang, Qi; Ma, Hongwei; Wu, Ji; Shen, Shun

2014-05-15

This paper described a novel application of PEGylated magnetic carbon nanotubes as solid-phase extraction nanosorbents for the determination of puerarin in rat plasma by high performance liquid chromatography (HPLC). A solvothermal method was employed for the synthesis of monodisperse magnetites anchored onto multi-walled carbon nanotubes (MWCNTs@Fe3O4). In order to enhance the water solubility of MWCNTs@Fe3O4 that ensured sufficient contact between nanosorbents and analytes in the sampling procedure, the obtained nanomaterials were further noncovalently functionalized using a phospholipids-polyethylene glycol (DSPE-PEG). The PEGylated MWCNTs@Fe3O4 nanomaterials had an extremely large surface area and exhibit a strong interaction capability for puerarin with π-π stacking interactions. The captured puerarin/nanosorbents were easily isolated from the plasma by placing a magnet, and desorbed by acetonitrile. The experimental variables affecting the extraction efficiency were investigated. The calibration curve of puerarin was linear from 0.01 to 20 μg/ml, and the limit of detection was 0.005 μg/ml. The precisions ranged from 2.7% to 3.5% for within-day measurement, and for between-day variation was in the range of 3.1-5.9%. The method recoveries were acquired from 95.2% to 98.0%. Moreover, the analytical performance obtained by PEGylated magnetic MWCNTs was also compared with that of magnetic MWCNTs. All results showed that our proposed method was an excellent alternative for the analysis of puerarin in rat plasma. Copyright © 2014 Elsevier B.V. All rights reserved.

Scaled-Up Production and Transport Applications of Graphitic Carbon Nanomaterials

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Saviers, Kimberly R.

Graphitic carbon nanomaterials enhance the performance of engineered systems for energy harvesting and storage. However, commercial availability remains largely cost-prohibitive due to technical barriers to mass production. This thesis examines both the scaled-up production and energy transport applications of graphitic materials. Cost driven-production of graphitic petals is developed, carbon nanotube array thermal interface materials enhance waste heat energy harvesting, and microsupercapacitors are visually examined using a new electroreflectance measurement method. Graphitic materials have previously been synthesized using batch-style processing methods with small sample sizes, limiting their commercial viability. In order to increase production throughput, a roll-to-roll radio-frequency plasma chemical vapor deposition method is employed to continuously deposit graphitic petals on carbon fiber tow. In consideration of a full production framework, efficient and informative characterization methods in the form of electrical resistance and electrochemical capacitance are highlighted. To co-optimize the functional characteristics of the material, the processing conditions are comprehensively varied using a data-driven predictive design of experiments method. Repeatable and reliable production of graphitic materials will enable a host of creative graphene-based devices to emerge into the marketplace. Two such applications are discussed in the remaining chapters. Waste heat is most efficiently harvested at high temperatures, such as vehicle exhaust systems near 600°C. However, the resistance to heat flux at the interfaces between the harvesting device and its surroundings is detrimental to the system-level performance. To study the performance of thermal interface materials up to 700°C, a reference bar measurement method was designed. Design considerations are discussed and compared to past implementations, particularly regarding radiation heat flux and thermal

Molecular interactions and thermal transport in ionic liquids with carbon nanomaterials.

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França, João M P; Nieto de Castro, Carlos A; Pádua, Agílio A H

2017-07-05

We used molecular dynamics simulation to study the effect of suspended carbon nanomaterials, nanotubes and graphene sheets, on the thermal conductivity of ionic liquids, an issue related to understanding the properties of nanofluids. One important aspect that we developed is an atomistic model of the interactions between the organic ions and carbon nanomaterials, so we did not rely on existing force fields for small organic molecules or assume simple combining rules to describe the interactions at the liquid/material interface. Instead, we used quantum calculations with a density functional suitable for non-covalent interactions to parameterize an interaction model, including van der Waals terms and also atomic partial charges on the materials. We fitted a n-m interaction potential function with n values of 9 or 10 and m values between 5 and 8, so a 12-6 Lennard-Jones function would not fit the quantum calculations. For the atoms of ionic liquids and carbon nanomaterials interacting among themselves, we adopted existing models from the literature. We studied the imidazolium ionic liquids [C 4 C 1 im][SCN], [C 4 C 1 im][N(CN) 2 ], [C 4 C 1 im][C(CN) 3 ] and [C 4 C 1 im][(CF 3 SO 2 ) 2 N]. Attraction is stronger for cations (than for anions) above and below the π-system of the nanomaterials, whereas anions show stronger attraction for the hydrogenated edges. The ordering of ions around and inside (7,7) and (10,10) single-walled nanotubes, and near a stack of graphene sheets, was analysed in terms of density distribution functions. We verified that anions are found, as well as cations, in the first interfacial layer interacting with the materials, which is surprising given the interaction potential surfaces. The thermal conductivity of the ionic liquids and of composite systems containing one nanotube or one graphene stack in suspension was calculated using non-equilibrium molecular dynamics. Thermal conductivity was calculated along the axis of the nanotube and

Chemistry of carbon nanomaterials: Uses of lithium nanotube salts in organic syntheses and functionalization of graphite

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Chattopadhyay, Jayanta

The effective utilization of carbon nanomaterials, such as single-walled carbon nanotubes (SWNTs) and graphite, has been hindered due to difficulties (poor solubility, poly-dispersity) in processing. Therefore, a high degree of sidewall functionalization, either covalent or non-covalent, is often required to overcome these difficulties as the functionalized nanomaterials exhibit better solubility (either in organic solvents or in water), dispersity, manipulation, and processibility. This thesis presents a series of convenient and efficient organic synthetic routes to functionalize carbon nanomaterials. Carbon nanotube salts, prepared by treating SWNTs with lithium in liquid ammonia, react readily with aryl halides to yield aryl-functionalized SWNTs. These arylated SWNTs are soluble in methanol and water upon treatment with oleum. Similarly, SWNTs can be covalently functionalized by different heteroatoms (nitrogen, oxygen, and sulfur). Using the reductive alkylation approach, a synthetic scheme is designed to prepare long chain carboxylic acid functionalized SWNTs [SWNTs-(RCOOH)] that can react with (1) amine-terminated polyethylene glycol (PEG) chains to yield water-soluble biocompatible PEGylated SWNTs that are likely to be useful in a variety of biomedical applications; (2) polyethyleneimine (PEI) to prepare a SWNTs-PEI based adsorbent material that shows a four-fold improvement in the adsorption capacity of carbon dioxide over commonly used materials, making it useful for regenerable carbon dioxide removal in spaceflight; (3) chemically modified SWNTs-(RCOOH) to permit covalent bonding to the nylon matrix, thus allowing the formation of nylon 6,10 and nylon 6,10/SWNTs-(RCOOH) nanocomposites. Furthermore, we find that the lithium salts of carbon nanotubes serve as a source of electrons to induce polymerization of simple alkenes and alkynes onto the surface of carbon nanotubes. In the presence of sulfide/disulfide bonds, SWNT salts can initiate the single electron

Synthesis and electrochemical properties of composite galvanic Ni with carbon nanomaterials and PVD Mo coatings

International Nuclear Information System (INIS)

Drozdovich, V.B.; Chayeuski, V.V.; Zhdanok, S.A.; Barkovskaya, M.M.

2011-01-01

Double layer coatings Ni – Mo were obtained by electrolytic deposition of galvanic Ni and following arc PVD deposition of molybdenum. The ion plating coatings Mo on Ni foil and composition electrolytic Ni coatings with carbon nanomaterials (CNM) deposited on mild steel has been also investigated. Composite galvanic Ni coatings with CNM and ion plating coatings Mo contain separately obtained cubic α-Mo phase as well as fragmentary solid solution Mo in Ni. Such coatings exclude hydrogenation of Ni foundation in alkaline solution and possess enlarged electrocatalytic properties while emitting hydrogen and oxygen. Availability of carbon based nanomaterials in combined coatings is cause of an active absorption hydrogen after cathodic polarization. A formation on the surface layer of nanostructure solid solution (Ni, Mo) after compression plasma flows treatment with fixed parameters of patterns Mo/Ni/ mild steel take place. (authors)

Green processes for nanotechnology from inorganic to bioinspired nanomaterials

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Basiuk, Elena

2015-01-01

This book provides the state-of-the-art survey of green techniques in preparation of different classes of nanomaterials, with an emphasis on the use of renewable sources. Key topics covered include fabrication of nanomaterials using green techniques as well as their properties and applications, the use of renewable sources to obtain nanomaterials of different classes, from simple metal and metal oxide nanoparticles to complex bioinspired nanomaterials, economic contributions of nanotechnology to green and sustainable growth, and more. This is an ideal book for students, lecturers, researchers and engineers dealing with versatile (mainly chemical, biological, and medical) aspects of nanotechnology, including fabrication of nanomaterials using green techniques and their properties and applications. This book also: Maximizes reader insights into the design and fabrication of bioinspired nanomaterials and the design of complex bio-nanohybrids Covers many different applications for nanomaterials, bioinspired nanom...

Nuclear Magnetic Resonance (NMR) Spectroscopic Characterization of Nanomaterials and Biopolymers

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Guo, Chengchen

Nanomaterials have attracted considerable attention in recent research due to their wide applications in various fields such as material science, physical science, electrical engineering, and biomedical engineering. Researchers have developed many methods for synthesizing different types of nanostructures and have further applied them in various applications. However, in many cases, a molecular level understanding of nanoparticles and their associated surface chemistry is lacking investigation. Understanding the surface chemistry of nanomaterials is of great significance for obtaining a better understanding of the properties and functions of the nanomaterials. Nuclear magnetic resonance (NMR) spectroscopy can provide a familiar means of looking at the molecular structure of molecules bound to surfaces of nanomaterials as well as a method to determine the size of nanoparticles in solution. Here, a combination of NMR spectroscopic techniques including one- and two-dimensional NMR spectroscopies was used to investigate the surface chemistry and physical properties of some common nanomaterials, including for example, thiol-protected gold nanostructures and biomolecule-capped silica nanoparticles. Silk is a natural protein fiber that features unique properties such as excellent mechanical properties, biocompatibility, and non-linear optical properties. These appealing physical properties originate from the silk structure, and therefore, the structural analysis of silk is of great importance for revealing the mystery of these impressive properties and developing novel silk-based biomaterials as well. Here, solid-state NMR spectroscopy was used to elucidate the secondary structure of silk proteins in N. clavipes spider dragline silk and B. mori silkworm silk. It is found that the Gly-Gly-X (X=Leu, Tyr, Gln) motif in spider dragline silk is not in a beta-sheet or alpha-helix structure and is very likely to be present in a disordered structure with evidence for 31-helix

Nanomaterials for biosensing applications: A Review

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Michael eHolzinger

2014-08-01

Full Text Available A biosensor device is defined by its biological, or bioinspired receptor unit with unique specificities towards corresponding analytes. These analytes are often of biological origin like DNAs or proteins from the immune system (antibodies, antigens of diseases or infections. Such analytes can also be simple molecules like glucose or pollutants when a biological receptor unit with particular specificity is available. One of many other challenges in biosensor development is the efficient signal capture of the biological recognition event (transduction. Such transducers translate the interaction of the analyte with the biological element into electrochemical, electrochemiluminescent, magnetic, gravimetric, or optical signals. In order to increase sensitivities and to lower detection limits down to even individual molecules, nanomaterials are promising candidates due to the possibility to immobilize an enhanced quantity of bioreceptor units at reduced volumes and even to act itself as transduction element. Among such nanomaterials, gold nanoparticles, semi-conductor quantum dots, polymer nanoparticles, carbon nanotubes, nanodiamonds, and graphene are intensively studied. Due to the vast evolution of this research field, this review summarizes in a non-exhaustive way the advantages of nanomaterials by focusing on nano-objects which provide further beneficial properties than just an enhanced surface area.

Spectral absorption of unpolarized light through nano-materials in the absence of a magnetic field

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Luminosu I.

2008-01-01

Full Text Available A study of optical properties, such as light absorption, of a colloidal nano-material, provides information on the biphasic, solid - liquid system microstructure. The nano-material under study is a magnetic liquid (ferrofluid. The disperser agent is petroleum mineral oil and the dispersed material is a brown spar powder (nano-particles. The stabilizer is oleic acid. Light absorption through ferrofluid samples reveals the tendency of solid particles in a colloidal solution to form aggregates. The paper emphasizes the linear dependence between the spectral absorption coefficient, concentration and wavelength. The aggregates cause deviations of the extinction coefficient from values according to the Bouger-Lambert-Beer law. Fe3O4 aggregates sized 58.76 nm are formed in the system. The average number of nano-particles forming aggregates is 6. The magnetic liquid to be studied is secure stable and, thus, trustful in technological and biological applications.

Poly(lactic acid Composites Containing Carbon-Based Nanomaterials: A Review

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Carolina Gonçalves

2017-07-01

Full Text Available Poly(lactic acid (PLA is a green alternative to petrochemical commodity plastics, used in packaging, agricultural products, disposable materials, textiles, and automotive composites. It is also approved by regulatory authorities for several biomedical applications. However, for some uses it is required that some of its properties be improved, namely in terms of thermo-mechanical and electrical performance. The incorporation of nanofillers is a common approach to attain this goal. The outstanding properties of carbon-based nanomaterials (CBN have caused a surge in research works dealing with PLA/CBN composites. The available information is compiled and reviewed, focusing on PLA/CNT (carbon nanotubes and PLA/GBM (graphene-based materials composites. The production methods, and the effects of CBN loading on PLA properties, namely mechanical, thermal, electrical, and biological, are discussed.

Facile synthesis of thiol-polyethylene glycol functionalized magnetic titania nanomaterials for highly efficient enrichment of N-linked glycopeptides.

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Wang, Jiawen; Yao, Jizong; Sun, Nianrong; Deng, Chunhui

2017-08-25

As protein N-glycosylation involved in generation and development of various cancers and diseases, it is vital to capture glycopeptides from complex biological samples for biomarker discovery. In this work, by taking advantages of the interaction between titania and thiol groups, thiol-polyethylene glycol functionalized magnetic titania nanomaterials (denoted as Fe 3 O 4 @TiO 2 @PEG) were firstly fabricated as an excellent hydrophilic adsorbent of N-linked glycopeptides. On one hand, the special interaction of titanium-thiol makes the synthetic manipulation simple and provides a new idea for design and synthesis of novel nanomaterials; on the other hand, strong magnetic response could realize rapid separation and the outstanding hydrophilicity of polyethylene glycol makes Fe 3 O 4 @TiO 2 @PEG nanomaterials show superior performance for glycopeptides enrichment with ultralow limit of detection (0.1mol/μL) and high selectivity (1:100). As a result, 24 and 33 glycopeptides enriched from HRP and IgG digests were identified respectively by MALDI-TOF MS, and 300 glycopeptides corresponding to 106 glycoproteins were recognized from merely 2μL human serum, indicating a great potential of Fe 3 O 4 @TiO 2 @PEG nanomaterials for glycoproteomic research. Copyright © 2017 Elsevier B.V. All rights reserved.

Electronic structure and transport properties of quasi-one-dimensional carbon nanomaterials

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Y. N. Wu

2017-09-01

Full Text Available Based on the density functional theory combined with the nonequilibrium Green’s function, the influence of the wrinkle on the electronic structures and transport properties of quasi-one-dimensional carbon nanomaterials have been investigated, in which the wrinkled armchair graphene nanoribbons (wAGNRs and the composite of AGNRs and single walled carbon nanotubes (SWCNTs were considered with different connection of ripples. The wrinkle adjusts the electronic structures and transport properties of AGNRs. With the change of the strain, the wAGNRs for three width families reveal different electrical behavior. The band gap of AGNR(6 increases in the presence of the wrinkle, which is opposite to that of AGNR(5 and AGNR(7. The transport of AGNRs with the widths 6 or 7 has been modified by the wrinkle, especially by the number of isolated ripples, but it is insensitive to the strain. The nanojunctions constructed by AGNRs and SWCNTs can form the quantum wells, and some specific states are confined in wAGNRs. Although these nanojunctions exhibit the metallic, they have poor conductance due to the wrinkle. The filling of C20 into SWCNT has less influence on the electronic structure and transport of the junctions. The width and connection type of ripples have greatly influenced on the electronic structures and transport properties of quasi-one-dimensional nanomaterials.

Electronic structure and transport properties of quasi-one-dimensional carbon nanomaterials

Science.gov (United States)

Wu, Y. N.; Cheng, P.; Wu, M. J.; Zhu, H.; Xiang, Q.; Ni, J.

2017-09-01

Based on the density functional theory combined with the nonequilibrium Green's function, the influence of the wrinkle on the electronic structures and transport properties of quasi-one-dimensional carbon nanomaterials have been investigated, in which the wrinkled armchair graphene nanoribbons (wAGNRs) and the composite of AGNRs and single walled carbon nanotubes (SWCNTs) were considered with different connection of ripples. The wrinkle adjusts the electronic structures and transport properties of AGNRs. With the change of the strain, the wAGNRs for three width families reveal different electrical behavior. The band gap of AGNR(6) increases in the presence of the wrinkle, which is opposite to that of AGNR(5) and AGNR(7). The transport of AGNRs with the widths 6 or 7 has been modified by the wrinkle, especially by the number of isolated ripples, but it is insensitive to the strain. The nanojunctions constructed by AGNRs and SWCNTs can form the quantum wells, and some specific states are confined in wAGNRs. Although these nanojunctions exhibit the metallic, they have poor conductance due to the wrinkle. The filling of C20 into SWCNT has less influence on the electronic structure and transport of the junctions. The width and connection type of ripples have greatly influenced on the electronic structures and transport properties of quasi-one-dimensional nanomaterials.

Recent trends in nanomaterial-based microanalytical systems for the speciation of trace elements: A critical review.

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Tseng, Wei-Chang; Hsu, Keng-Chang; Shiea, Christopher Stephen; Huang, Yeou-Lih

2015-07-16

Trace element speciation in biomedical and environmental science has gained increasing attention over the past decade as researchers have begun to realize its importance in toxicological studies. Several nanomaterials, including titanium dioxide nanoparticles (nano-TiO2), carbon nanotubes (CNTs), and magnetic nanoparticles (MNPs), have been used as sorbents to separate and preconcentrate trace element species prior to detection through mass spectrometry or optical spectroscopy. Recently, these nanomaterial-based speciation techniques have been integrated with microfluidics to minimize sample and reagent consumption and simplify analyses. This review provides a critical look into the present state and recent applications of nanomaterial-based microanalytical systems in the speciation of trace elements. The adsorption and preconcentration efficiencies, sample volume requirements, and detection limits of these nanomaterial-based speciation techniques are detailed, and their applications in environmental and biological analyses are discussed. Current perspectives and future trends into the increasing use of nanomaterial-based microfluidic techniques for trace element speciation are highlighted. Copyright © 2015 Elsevier B.V. All rights reserved.

Terahertz Dynamics in Carbon Nanomaterials

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Kono, Junichiro

2012-02-01

This NSF Partnerships for International Research and Education (PIRE) project supports a unique interdisciplinary and international partnership investigating terahertz (THz) dynamics in nanostructures. The 0.1 to 10 THz frequency range of the electromagnetic spectrum is where electrical transport and optical transitions merge, offering exciting opportunities to study a variety of novel physical phenomena in condensed matter. By combining THz technology and nanotechnology, we can advance our understanding of THz physics while improving and developing THz devices. Specifically, this PIRE research explores THz dynamics of electrons in carbon nanomaterials, namely, nanotubes and graphene --- low-dimensional, sp^2-bonded carbon systems with unique finite-frequency properties. Japan and the U.S. are global leaders in both THz research and carbon research, and stimulating cooperation is critical to further advance THz science and to commercialize products developed in the lab. However, obstacles exist for international collaboration --- primarily linguistic and cultural barriers --- and this PIRE project aims to address these barriers through the integration of our research and education programs. Our strong educational portfolio endeavours to cultivate interest in nanotechnology amongst young U.S. undergraduate students and encourage them to pursue graduate study and academic research in the physical sciences, especially those from underrepresented groups. Our award-winning International Research Experience for Undergraduates Program, NanoJapan, provides structured research internships in Japanese university laboratories with Japanese mentors --- recognized as a model international education program for science and engineering students. The project builds the skill sets of nanoscience researchers and students by cultivating international and inter-cultural awareness, research expertise, and specific academic interests in nanotechnology. U.S. project partners include Rice

How Do Enzymes 'Meet' Nanoparticles and Nanomaterials?

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Chen, Ming; Zeng, Guangming; Xu, Piao; Lai, Cui; Tang, Lin

2017-11-01

Enzymes are fundamental biological catalysts responsible for biological regulation and metabolism. The opportunity for enzymes to 'meet' nanoparticles and nanomaterials is rapidly increasing due to growing demands for applications in nanomaterial design, environmental monitoring, biochemical engineering, and biomedicine. Therefore, understanding the nature of nanomaterial-enzyme interactions is becoming important. Since 2014, enzymes have been used to modify, degrade, or make nanoparticles/nanomaterials, while numerous nanoparticles/nanomaterials have been used as materials for enzymatic immobilization and biosensors and as enzyme mimicry. Among the various nanoparticles and nanomaterials, metal nanoparticles and carbon nanomaterials have received extensive attention due to their fascinating properties. This review provides an overview about how enzymes meet nanoparticles and nanomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nano-biomedical approaches of cancer therapy using carbon based and magnetic nanomaterials

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Karmakar, Alokita

Since the inception of nanoparticles, they have affected almost each and every field of modern science and technology both in terms of research and application. Due to its subcellular level size and ease of modification for biological and medical purposes, nanoparticles have contributed greatly in various field of biomedical reaserch including cancer research. In this dissertation, emphasis has been given on an important area of research of a multi-modal anticancer therapeutic approach using carbon-based and magnetic inorganic nanoparticles. Ethylenediamine functionalized single wall carbon nanotubes (SWNTs) have been used to deliver a functional copy of p53 gene in a plasmid construct, to human breast cancer cell line MCF-7, in order to restore the activity of p53 protein, which in this case is extremely short-lived. The attachment of the plasmid on the SWNTs was determined by atomic force microscopy. The nanutobe has successfully delivered the plasmid into the MCF-7 cell which follows the expression of the p53 protein into the cell as evidenced by the expression of Green fluorescence protein which was tagged to p53 plasmid. Upon expression, the functional activity of the p53 protein was found to be significantly restored as after 72 hours of incubation ~40% of cancer cells were apoptotic. Apoptosis was further determined by caspase assay. In chapter 3, we have used SWNTs to accomplish the targeted delivery by functionalizing it with human epidermal growth factor (EGF). As EGF receptor is over expressed in many of the cancer cells, it is possible to deliver any chemotherapeutic agents selectively to those cancer cells. We used EGF conjugated to SWNTs for targeted delivery to PANC-1 cells. Results indicate EGF-functionalized SWNTs accumulate more into PANC-1 cells compared to only SWNTs only. Upon targeting, Raman spectroscopy and ELIZA assay were used to determine the association and dissociation pattern of the targeted SWCNTs. 2D-Raman mapping was used to show

Different magnetic properties of rhombohedral and cubic Ni2+ doped indium oxide nanomaterials

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Qingbo Sun

2011-12-01

Full Text Available Transition metal ions doped indium oxide nanomaterials were potentially used as a kind of diluted magnetic semiconductors in transparent spintronic devices. In this paper, the influences of Ni2+ doped contents and rhombohedral or cubic crystalline structures of indium oxide on magnetic properties were investigated. We found that the magnetic properties of Ni2+ doped indium oxide could be transferred from room temperature ferromagnetisms to paramagnetic properties with increments of doped contents. Moreover, the different crystalline structures of indium oxide also greatly affected the room temperature ferromagnetisms due to different lattice constants and almost had no effects on their paramagnetic properties. In addition, both the ferromagnetic and paramagnetic properties were demonstrated to be intrinsic and not caused by impurities.

National Survey of Workplaces Handling and Manufacturing Nanomaterials, Exposure to and Health Effects of Nanomaterials, and Evaluation of Nanomaterial Safety Data Sheets

Science.gov (United States)

2016-01-01

A national survey on workplace environment nanomaterial handling and manufacturing was conducted in 2014. Workplaces relevant to nanomaterials were in the order of TiO2 (91), SiO2 (88), carbon black (84), Ag (35), Al2O3 (35), ZnO (34), Pb (33), and CeO2 (31). The survey results indicated that the number of workplaces handling or manufacturing nanomaterials was 340 (0.27% of total 126,846) workplaces. The number of nanomaterials used and products was 546 (1.60 per company) and 583 (1.71 per company), respectively. For most workplaces, the results on exposure to hazardous particulate materials, including nanomaterials, were below current OELs, yet a few workplaces were above the action level. As regards the health status of workers, 9 workers were diagnosed with a suspected respiratory occupational disease, where 7 were recommended for regular follow-up health monitoring. 125 safety data sheets (SDSs) were collected from the nanomaterial-relevant workplaces and evaluated for their completeness and reliability. Only 4 CNT SDSs (3.2%) included the term nanomaterial, while most nanomaterial SDSs were not regularly updated and lacked hazard information. When taken together, the current analysis provides valuable national-level information on the exposure and health status of workers that can guide the next policy steps for nanomaterial management in the workplace. PMID:27556041

Cellulose nanomaterials in water treatment technologies.

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Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

2015-05-05

Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization.

High Performance and Economic Supercapacitors for Energy Storage Based on Carbon Nanomaterials

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Samuilov, Vladimir; Farshid, Behzad; Frenkel, Alexander; Sensor CAT at Stony Brook Team

2015-03-01

We designed and manufactured very inexpensive prototypes of supercapacitors for energy storage based on carbon nanomaterials comprised of: reduced graphene oxide (RGOs) and carbon nanotubes (CNTs) as electrodes filled with polymer gel electrolytes. The electrochemical properties of supercapacitors made using these materials were compared and analyzed. A significant tradeoff between the energy density and the power density was determined; RGO electrodes demonstrated the highest energy density, while composite RGO/CNT electrodes showed the highest power density. The thickness of the RGO electrode was varied to determine its effect on the power density of the supercapacitor and results showed that with decreasing electrode thickness power density would increase. The specific capacitances of over 600 F/g were observed.

Carbon-Based Nanomaterials in Biomass-Based Fuel-Fed Fuel Cells

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Le Quynh Hoa

2017-11-01

Full Text Available Environmental and sustainable economical concerns are generating a growing interest in biofuels predominantly produced from biomass. It would be ideal if an energy conversion device could directly extract energy from a sustainable energy resource such as biomass. Unfortunately, up to now, such a direct conversion device produces insufficient power to meet the demand of practical applications. To realize the future of biofuel-fed fuel cells as a green energy conversion device, efforts have been devoted to the development of carbon-based nanomaterials with tunable electronic and surface characteristics to act as efficient metal-free electrocatalysts and/or as supporting matrix for metal-based electrocatalysts. We present here a mini review on the recent advances in carbon-based catalysts for each type of biofuel-fed/biofuel cells that directly/indirectly extract energy from biomass resources, and discuss the challenges and perspectives in this developing field.

Tissue-specific direct microtransfer of nanomaterials into Drosophila embryos as a versatile in vivo test bed for nanomaterial toxicity assessment

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Vega-Alvarez S

2014-04-01

Full Text Available Sasha Vega-Alvarez,1 Adriana Herrera,2 Carlos Rinaldi,2–4 Franklin A Carrero-Martínez1,5 1Department of Biology, 2Department of Chemical Engineering, University of Puerto Rico-Mayagüez, Mayagüez, Puerto Rico; 3J Crayton Pruitt Family Department of Biomedical Engineering, 4Department of Chemical Engineering, University of Florida, Gainesville, FL, USA; 5Department of Anatomy and Neuroscience, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico Abstract: Nanomaterials are the subject of intense research, focused on their synthesis, modification, and biomedical applications. Increased nanomaterial production and their wide range of applications imply a higher risk of human and environmental exposure. Unfortunately, neither environmental effects nor toxicity of nanomaterials to organisms are fully understood. Cost-effective, rapid toxicity assays requiring minimal amounts of materials are needed to establish both their biomedical potential and environmental safety standards. Drosophila exemplifies an efficient and cost-effective model organism with a vast repertoire of in vivo tools and techniques, all with high-throughput scalability and screening feasibility throughout its life cycle. Here we report tissue specific nanomaterial assessment through direct microtransfer into target tissues. We tested several nanomaterials with potential biomedical applications such as single-wall carbon nanotubes, multiwall carbon nanotubes, silver, gold, titanium dioxide, and iron oxide nanoparticles. Assessment of nanomaterial toxicity was conducted by evaluating progression through developmental morphological milestones in Drosophila. This cost-effective assessment method is amenable to high-throughput screening. Keywords: nanotoxicity, Drosophila, microtransfer, nanoparticle, iron oxide, silver, gold, titanium dioxide, carbon nanotube

Nanomaterials as stationary phases and supports in liquid chromatography.

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Beeram, Sandya R; Rodriguez, Elliott; Doddavenkatanna, Suresh; Li, Zhao; Pekarek, Allegra; Peev, Darin; Goerl, Kathryn; Trovato, Gianfranco; Hofmann, Tino; Hage, David S

2017-10-01

The development of various nanomaterials over the last few decades has led to many applications for these materials in liquid chromatography (LC). This review will look at the types of nanomaterials that have been incorporated into LC systems and the applications that have been explored for such systems. A number of carbon-based nanomaterials and inorganic nanomaterials have been considered for use in LC, ranging from carbon nanotubes, fullerenes and nanodiamonds to metal nanoparticles and nanostructures based on silica, alumina, zirconia and titanium dioxide. Many ways have been described for incorporating these nanomaterials into LC systems. These methods have included covalent immobilization, adsorption, entrapment, and the synthesis or direct development of nanomaterials as part of a chromatographic support. Nanomaterials have been used in many types of LC. These applications have included the reversed-phase, normal-phase, ion-exchange, and affinity modes of LC, as well as related methods such as chiral separations, ion-pair chromatography and hydrophilic interaction liquid chromatography. Both small and large analytes (e.g., dyes, drugs, amino acids, peptides and proteins) have been used to evaluate possible applications for these nanomaterial-based methods. The use of nanomaterials in columns, capillaries and planar chromatography has been considered as part of these efforts. Potential advantages of nanomaterials in these applications have included their good chemical and physical stabilities, the variety of interactions many nanomaterials can have with analytes, and their unique retention properties in some separation formats. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation and characterization of flower-like gold nanomaterials and iron oxide/gold composite nanomaterials

International Nuclear Information System (INIS)

Yang Zusing; Lin, Z H; Tang, C-Y; Chang, H-T

2007-01-01

We have successfully synthesized flower-like gold nanomaterials and Fe 3 O 4 /Au composite nanomaterials through the use of wet chemical methods in aqueous solution. In the presence of 0.5 mM citrate, 0.313 mM poly(ethylene glycol), and 109.72 mM sodium acetate (NaOAc), we prepared Au nanoflowers (NFs) having diameters ranging from 300 to 400 nm in aqueous solution after the reduction of Au ions at room temperature for 10 min. In the presence of spherical Fe 3 O 4 nanomaterials, we applied a similar synthetic method to prepare Fe 3 O 4 /Au composite nanomaterials, including nanowires (NWs) that have a length of 1.58 μm and a width of 28.3 nm. We conducted energy-dispersive x-ray analysis, scanning electron microscopy, transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, and x-ray powder diffraction measurements to characterize the as-prepared flower-like Au nanomaterials and Fe 3 O 4 /Au composite nanomaterials. From time-evolution TEM measurements, we suggested that Au atoms that were bound to the Fe 3 O 4 nanomaterials grew to form Fe 3 O 4 /Au composite nanomaterials. The as-prepared Au NFs absorbed light strongly in the visible-near-infrared (Vis-NIR) region (500-1200 nm). The Fe 3 O 4 /Au composite nanomaterials had electronic conductivities greater than 100 nA at an applied voltage of 20 mV, which induced a temperature increase of 20.5 ± 0.5 deg. C under an alternating magnetic field (62 μT)

Carbon magnetic resonance spectroscopy on carbon-13-labeled uracil in 5S ribonucleic acid

International Nuclear Information System (INIS)

Hamill, W.D.; Grant, D.M.; Cooper, R.B.; Harmon, S.A.

1978-01-01

The carbon-13 nuclear magnetic resonance spectra of the 13 C-enriched C-4 uridine carbons in 5S ribosomal ribonucleic acid of Salmonella typhimurium, strain JL-1055, was obtained. The most striking feature of the 5S RNA spectrum was the large number of well-resolved lines in the uridine band covering a chemical shift range of approximately 3.6 ppM. This data was used to obtain information on the secondary structure. The number of uridines involved in secondary interactions is estimated to be at least 75% and may be as high as 95%

Measuring Nanomaterial Release from Carbon Nanotube Composites: Review of the State of the Science

International Nuclear Information System (INIS)

Harper, Stacey; Wohlleben, Wendel; Doa, Maria; Nowack, Bernd; Clancy, Shaun; Canady, Richard; Maynard, Andrew

2015-01-01

Hazard studies of “as-produced” nanomaterials are increasingly available, yet a critical gap exists in exposure science that may impede safe development of nanomaterials. The gap is that we do not understand what is actually released because nanomaterials can change when released in ways that are not understood. We also generally do not have methods capable of quantitatively measuring what is released to support dose assessment. This review presents a case study of multi-walled carbon nanotubes (MWCNTs) for the measurement challenge to bridge this gap. As the use and value of MWCNTs increases, methods to measure what is released in ways relevant to risk evaluation are critically needed if products containing these materials are to be economically, environmentally, and socially sustainable. This review draws on the input of over 50 experts engaged in a program of workshops and technical report writing to address the release of MWCNTs from nanocomposite materials across their life cycle. The expert analyses reveals that new and sophisticated methods are required to measure and assess MWCNT exposures for realistic exposure scenarios. Furthermore, method requirements vary with the materials and conditions of release across life cycle stages of products. While review shows that the likelihood of significant release of MWCNTs appears to be low for many stages of composite life cycle, measurement methods are needed so that exposures from MWCNT-composites are understood and managed. In addition, there is an immediate need to refocus attention from study of “as-produced” nanomaterials to coordinated research on actual release scenarios. (paper)

Biophysical influence of airborne carbon nanomaterials on natural pulmonary surfactant.

Science.gov (United States)

Valle, Russell P; Wu, Tony; Zuo, Yi Y

2015-05-26

Inhalation of nanoparticles (NP), including lightweight airborne carbonaceous nanomaterials (CNM), poses a direct and systemic health threat to those who handle them. Inhaled NP penetrate deep pulmonary structures in which they first interact with the pulmonary surfactant (PS) lining at the alveolar air-water interface. In spite of many research efforts, there is a gap of knowledge between in vitro biophysical study and in vivo inhalation toxicology since all existing biophysical models handle NP-PS interactions in the liquid phase. This technical limitation, inherent in current in vitro methodologies, makes it impossible to simulate how airborne NP deposit at the PS film and interact with it. Existing in vitro NP-PS studies using liquid-suspended particles have been shown to artificially inflate the no-observed adverse effect level of NP exposure when compared to in vivo inhalation studies and international occupational exposure limits (OELs). Here, we developed an in vitro methodology called the constrained drop surfactometer (CDS) to quantitatively study PS inhibition by airborne CNM. We show that airborne multiwalled carbon nanotubes and graphene nanoplatelets induce a concentration-dependent PS inhibition under physiologically relevant conditions. The CNM aerosol concentrations controlled in the CDS are comparable to those defined in international OELs. Development of the CDS has the potential to advance our understanding of how submicron airborne nanomaterials affect the PS lining of the lung.

Synthesis, photophysical analysis, and in vitro cytotoxicity assessment of the multifunctional (magnetic and luminescent) core@shell nanomaterial based on lanthanide-doped orthovanadates

International Nuclear Information System (INIS)

Szczeszak, Agata; Ekner-Grzyb, Anna; Runowski, Marcin; Mrówczyńska, Lucyna; Grzyb, Tomasz; Lis, Stefan

2015-01-01

Rare earths orthovanadates (REVO 4 ) doped with luminescent lanthanide ions (Ln 3+ ) play an important role as promising light-emitting materials. Gadolinium orthovanadate exhibits strong absorption of ultraviolet radiation and as a matrix doped with Eu 3+ ions is well known for its efficient and intense red emission, induced by energy transfer from the VO 4 3− groups to Eu 3+ ions. In the presented study, Fe 3 O 4 @SiO 2 @GdVO 4 :Eu 3+ 5 % nanomaterial was investigated. The core@shell structures demonstrate attractive properties, such as higher thermal stability, enhanced water solubility, increased optical response, higher luminescence, longer decay times, and magnetic properties. Silica coating may protect nanocrystals from the surrounding environment. Therefore, such silica-covered nanoparticles (NPs) are successfully utilized in biomedical research. Multifunctional magnetic nanophosphors are very interesting due to their potential biomedical applications such as magnetic resonance imaging, hyperthermic treatment, and drug delivery. Therefore, the aim of our study was to investigate photophysical, chemical, and biological properties of multifunctional REVO 4 doped with Ln 3+ . Moreover, the studied NPs did not affect erythrocyte sedimentation rate, cell membrane permeability, and morphology of human red blood cells

Synthesis, photophysical analysis, and in vitro cytotoxicity assessment of the multifunctional (magnetic and luminescent) core@shell nanomaterial based on lanthanide-doped orthovanadates

Science.gov (United States)

Szczeszak, Agata; Ekner-Grzyb, Anna; Runowski, Marcin; Mrówczyńska, Lucyna; Grzyb, Tomasz; Lis, Stefan

2015-03-01

Rare earths orthovanadates (REVO4) doped with luminescent lanthanide ions (Ln3+) play an important role as promising light-emitting materials. Gadolinium orthovanadate exhibits strong absorption of ultraviolet radiation and as a matrix doped with Eu3+ ions is well known for its efficient and intense red emission, induced by energy transfer from the VO4 3- groups to Eu3+ ions. In the presented study, Fe3O4@SiO2@GdVO4:Eu3+ 5 % nanomaterial was investigated. The core@shell structures demonstrate attractive properties, such as higher thermal stability, enhanced water solubility, increased optical response, higher luminescence, longer decay times, and magnetic properties. Silica coating may protect nanocrystals from the surrounding environment. Therefore, such silica-covered nanoparticles (NPs) are successfully utilized in biomedical research. Multifunctional magnetic nanophosphors are very interesting due to their potential biomedical applications such as magnetic resonance imaging, hyperthermic treatment, and drug delivery. Therefore, the aim of our study was to investigate photophysical, chemical, and biological properties of multifunctional REVO4 doped with Ln3+. Moreover, the studied NPs did not affect erythrocyte sedimentation rate, cell membrane permeability, and morphology of human red blood cells.

Cellulose Nanomaterials in Water Treatment Technologies

Science.gov (United States)

Carpenter, Alexis Wells; de Lannoy, Charles François; Wiesner, Mark R.

2015-01-01

Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials’ potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials’ beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

Engineering carbon nanomaterials for future applications: energy and bio-sensor

Science.gov (United States)

Das, Santanu; Lahiri, Indranil; Kang, Chiwon; Choi, Wonbong

2011-06-01

This paper presents our recent results on carbon nanomaterials for applications in energy storage and bio-sensor. More specifically: (i) A novel binder-free carbon nanotubes (CNTs) structure as anode in Li-ion batteries. The interfacecontrolled CNT structure, synthesized through a two-step chemical vapor deposition (CVD) and directly grown on copper current collector, showed very high specific capacity - almost three times as that of graphite, excellent rate capability. (ii) A large scale graphene film was grown on Cu foil by thermal chemical vapor deposition and transferred to various substrates including PET, glass and silicon by using hot press lamination and etching process. The graphene/PET film shows high quality, flexible transparent conductive structure with unique electrical-mechanical properties; ~88.80 % light transmittance and ~ 100 Ω/sq sheet resistance. We demonstrate application of graphene/PET film as flexible and transparent electrode for field emission displays. (iii) Application of individual carbon nanotube as nanoelectrode for high sensitivity electrochemical sensor and device miniaturization. An individual CNT is split into a pair of nanoelectrodes with a gap between them. Single molecular-level detection of DNA hybridization was studied. Hybridization of the probe with its complementary strand results in an appreciable change in the electrical output signal.

Recent Development of Nanomaterial-Doped Conductive Polymers

Science.gov (United States)

Asyraf, Mohammad; Anwar, Mahmood; Sheng, Law Ming; Danquah, Michael K.

2017-12-01

Conductive polymers (CPs) have received significant research attention in material engineering for applications in microelectronics, micro-scale sensors, electromagnetic shielding, and micro actuators. Numerous research efforts have been focused on enhancing the conductivity of CPs by doping. Various conductive materials, such as metal nanoparticles and carbon-based nanoparticles, and structures, such as silver nanoparticles and graphene nanosheets, have been converted into polypyrrole and polypyrrole compounds as the precursors to developing hybrids, conjugates, or crystal nodes within the matrix to enhance the various structural properties, particularly the electrical conductivity. This article reviews nanomaterial doping of conductive polymers alongside technological advancements in the development and application of nanomaterial-doped polymeric systems. Emphasis is given to conductive nanomaterials such as nano-silver particles and carbon-based nanoparticles, graphene nano-sheets, fullerene, and carbon nanotubes (CNT) as dopants for polypyrrole-based CPs. The nature of induced electrical properties including electromagnetic absorption, electrical capacitance, and conductivities of polypyrrole systems is also discussed. The prospects and challenges associated with the development and application of CPs are also presented.

New Nanomaterials and Luminescent Optical Sensors for Detection of Hydrogen Peroxide

Directory of Open Access Journals (Sweden)

Natalia A. Burmistrova

2015-10-01

Full Text Available Accurate methods that can continuously detect low concentrations of hydrogen peroxide (H2O2 have a huge application potential in biological, pharmaceutical, clinical and environmental analysis. Luminescent probes and nanomaterials are used for fabrication of sensors for H2O2 that can be applied for these purposes. In contrast to previous reviews focusing on the chemical design of molecular probes for H2O2, this mini-review highlights the latest luminescent nanoparticular materials and new luminescent optical sensors for H2O2 in terms of the nanomaterial composition and luminescent receptor used in the sensors. The nanomaterial section is subdivided into schemes based on gold nanoparticles, polymeric nanoparticles with embedded enzymes, probes showing aggregation-induced emission enhancement, quantum dots, lanthanide-based nanoparticles and carbon based nanomaterials, respectively. Moreover, the sensors are ordered according to the type of luminescent receptor used within the sensor membranes. Among them are lanthanide complexes, metal-ligand complexes, oxidic nanoparticles and organic dyes. Further, the optical sensors are confined to those that are capable to monitor the concentration of H2O2 in a sample over time or are reusable. Optical sensors responding to gaseous H2O2 are not covered. All nanomaterials and sensors are characterized with respect to the analytical reaction towards H2O2, limit of detection (LOD, analytical range, electrolyte, pH and response time/incubation time. Applications to real samples are given. Finally, we assess the suitability of the nanomaterials to be used in membrane-based sensors and discuss future trends and perspectives of these sensors in biomedical research.

Genotoxicity of nanomaterials: DNA damage and micronuclei induced by carbon nanotubes and graphite nanofibres in human bronchial epithelial cells in vitro.

Science.gov (United States)

Lindberg, Hanna K; Falck, Ghita C-M; Suhonen, Satu; Vippola, Minnamari; Vanhala, Esa; Catalán, Julia; Savolainen, Kai; Norppa, Hannu

2009-05-08

Despite the increasing industrial use of different nanomaterials, data on their genotoxicity are scant. In the present study, we examined the potential genotoxic effects of carbon nanotubes (CNTs; >50% single-walled, approximately 40% other CNTs; 1.1 nm x 0.5-100 microm; Sigma-Aldrich) and graphite nanofibres (GNFs; 95%; outer diameter 80-200 nm, inner diameter 30-50 nm, length 5-20 microm; Sigma-Aldrich) in vitro. Genotoxicity was assessed by the single cell gel electrophoresis (comet) assay and the micronucleus assay (cytokinesis-block method) in human bronchial epithelial BEAS 2B cells cultured for 24h, 48h, or 72h with various doses (1-100 microg/cm(2), corresponding to 3.8-380 microg/ml) of the carbon nanomaterials. In the comet assay, CNTs induced a dose-dependent increase in DNA damage at all treatment times, with a statistically significant effect starting at the lowest dose tested. GNFs increased DNA damage at all doses in the 24-h treatment, at two doses (40 and 100 microg/cm(2)) in the 48-h treatment (dose-dependent effect) and at four doses (lowest 10 microg/cm(2)) in the 72-h treatment. In the micronucleus assay, no increase in micronucleated cells was observed with either of the nanomaterials after the 24-h treatment or with CNTs after the 72-h treatment. The 48-h treatment caused a significant increase in micronucleated cells at three doses (lowest 10 microg/cm(2)) of CNTs and at two doses (5 and 10 microg/cm(2)) of GNFs. The 72-h treatment with GNFs increased micronucleated cells at four doses (lowest 10 microg/cm(2)). No dose-dependent effects were seen in the micronucleus assay. The presence of carbon nanomaterial on the microscopic slides disturbed the micronucleus analysis and made it impossible at levels higher than 20 microg/cm(2) of GNFs in the 24-h and 48-h treatments. In conclusion, our results suggest that both CNTs and GNFs are genotoxic in human bronchial epithelial BEAS 2B cells in vitro. This activity may be due to the fibrous nature

Computational studies on the interactions of nanomaterials with proteins and their impacts

International Nuclear Information System (INIS)

An De-Yi; Li Jing-Yuan; Su Ji-Guo; Li Chun-Hua

2015-01-01

The intensive concern over the biosafety of nanomaterials demands the systematic study of the mechanisms underlying their biological effects. Many of the effects of nanomaterials can be attributed to their interactions with proteins and their impacts on protein function. On the other hand, nanomaterials show potential for a variety of biomedical applications, many of which also involve direct interactions with proteins. In this paper, we review some recent computational studies on this subject, especially those investigating the interactions of carbon and gold nanomaterials. Beside hydrophobic and π-stacking interactions, the mode of interaction of carbon nanomaterials can also be regulated by their functional groups. The coatings of gold nanomaterials similarly adjust their mode of interaction, in addition to coordination interactions with the sulfur groups of cysteine residues and the imidazole groups of histidine residues. Nanomaterials can interact with multiple proteins and their impacts on protein activity are attributed to a wide spectrum of mechanisms. These findings on the mechanisms of nanomaterial–protein interactions can further guide the design and development of nanomaterials to realize their application in disease diagnosis and treatment. (paper)

Magnetically responsive calcium carbonate microcrystals.

Science.gov (United States)

Fakhrullin, Rawil F; Bikmullin, Aidar G; Nurgaliev, Danis K

2009-09-01

Here we report the fabrication of magnetically responsive calcium carbonate microcrystals produced by coprecipitation of calcium carbonate in the presence of citrate-stabilized iron oxide nanoparticles. We demonstrate that the calcite microcrystals obtained possess superparamagnetic properties due to incorporated magnetite nanoparticles and can be manipulated by an external magnetic field. The microcrystals doped with magnetic nanoparticles were utilized as templates for the fabrication of hollow polyelectrolyte microcapsules, which retain the magnetic properties of the sacrificial cores and might be spatially manipulated using a permanent magnet, thus providing the magnetic-field-facilitated delivery and separation of materials templated on magnetically responsive calcite microcrystals.

Relationship between Organic Carbon Runoff to River and Land Cover

Science.gov (United States)

Kim, G. S.; Lee, S. G.; Lim, C. H.; Lee, W.; Yoo, S.; Kim, S. J.; Heo, S.; Lee, W. K.

2017-12-01

Carbon is an important unit in understanding the ecosystem and energy circulation. Each ecosystem, land, water, and atmosphere, is interconnected through the exchange of energy and organic carbon. In the rivers, primary producers utilize the organic carbon from the land. Understanding the organic carbon uptake into the river is important for understanding the mechanism of river ecosystems. The main organic carbon source of the river is land. However, it is difficult to observe the amount of organic carbon runoff to the river. Therefore, an indirect method should be used to estimate the amount of organic carbon runoff to the river. The organic carbon inflow is caused by the runoff of organic carbon dissolved in water or the inflow of organic carbon particles by soil loss. Therefore, the hydrological model was used to estimate organic carbon runoff through the flow of water. The land cover correlates with soil respiration, soil loss, and so on, and the organic carbon runoff coefficient will be estimated to the river by land cover. Using the organic carbon concentration from water quality data observed at each point in the river, we estimate the amount of organic carbon released from the land. The reason is that the runoff from the watershed converges into the rivers in the watershed, the watershed simulation is conducted based on the water quality data observation point. This defines a watershed that affects organic carbon observation sites. The flow rate of each watershed is calculated by the SWAT (Soil and Water Assessment Tool), and the total organic carbon runoff is calculated by using flow rate and organic carbon concentration. This is compared with the factors related to the amount of organic carbon such as land cover, soil loss, and soil organic carbon, and spatial analysis is carried out to estimate the organic carbon runoff coefficient per land cover.

Nanomaterials for In Vivo Imaging.

Science.gov (United States)

Smith, Bryan Ronain; Gambhir, Sanjiv Sam

2017-02-08

In vivo imaging, which enables us to peer deeply within living subjects, is producing tremendous opportunities both for clinical diagnostics and as a research tool. Contrast material is often required to clearly visualize the functional architecture of physiological structures. Recent advances in nanomaterials are becoming pivotal to generate the high-resolution, high-contrast images needed for accurate, precision diagnostics. Nanomaterials are playing major roles in imaging by delivering large imaging payloads, yielding improved sensitivity, multiplexing capacity, and modularity of design. Indeed, for several imaging modalities, nanomaterials are now not simply ancillary contrast entities, but are instead the original and sole source of image signal that make possible the modality's existence. We address the physicochemical makeup/design of nanomaterials through the lens of the physical properties that produce contrast signal for the cognate imaging modality-we stratify nanomaterials on the basis of their (i) magnetic, (ii) optical, (iii) acoustic, and/or (iv) nuclear properties. We evaluate them for their ability to provide relevant information under preclinical and clinical circumstances, their in vivo safety profiles (which are being incorporated into their chemical design), their modularity in being fused to create multimodal nanomaterials (spanning multiple different physical imaging modalities and therapeutic/theranostic capabilities), their key properties, and critically their likelihood to be clinically translated.

Carbon based magnetism an overview of the magnetism of metal free carbon-based compounds and materials

CERN Document Server

Makarova, Tatiana

2006-01-01

Magnetism is one of the most intriguing phenomena observed in nature. Magnetism is relevant to physics and geology, biology and chemistry. Traditional magnets, an ubiquitous part of many everyday gadgets, are made of heavy iron- or nickel based materials. Recently there have been reports on the observation of magnetism in carbon, a very light and biocompatible element. Metal-free carbon structures exhibiting magnetic ordering represent a new class of materials and open a novel field of research that could lead to many new technologies. · The most complete, detailed, and accurate Guide in the magnetism of carbon · Dynamically written by the leading experts · Deals with recent scientific highlights · Gathers together chemists and physicists, theoreticians and experimentalists · Unified treatment rather than a series of individually authored papers · Description of genuine organic molecular ferromagnets · Unique description of new carbon materials with Curie temperatures well above ambient.

Bioavailability of Carbon Nanomaterial-Adsorbed Polycyclic Aromatic Hydrocarbons to Pimphales promelas: Influence of Adsorbate Molecular Size and Configuration.

Science.gov (United States)

Linard, Erica N; Apul, Onur G; Karanfil, Tanju; van den Hurk, Peter; Klaine, Stephen J

2017-08-15

Despite carbon nanomaterials' (CNMs) potential to alter the bioavailability of adsorbed contaminants, information characterizing the relationship between adsorption behavior and bioavailability of CNM-adsorbed contaminants is still limited. To investigate the influence of CNM morphology and organic contaminant (OC) physicochemical properties on this relationship, adsorption isotherms were generated for a suite of polycyclic aromatic hydrocarbons (PAHs) on multiwalled carbon nanotubes (MWCNTs) and exfoliated graphene (GN) in conjunction with determining the bioavailability of the adsorbed PAHs to Pimphales promelas using bile analysis via fluorescence spectroscopy. Although it appeared that GN adsorbed PAHs indiscriminately compared to MWCNTs, the subsequent bioavailability of GN-adsorbed PAHs was more sensitive to PAH morphology than MWCNTs. GN was effective at reducing bioavailability of linear PAHs by ∼70%, but had little impact on angular PAHs. MWCNTs were sensitive to molecular size, where bioavailability of two-ringed naphthalene was reduced by ∼80%, while bioavailability of the larger PAHs was reduced by less than 50%. Furthermore, the reduction in bioavailability of CNM-adsorbed PAHs was negatively correlated with the amount of CNM surface area covered by the adsorbed-PAHs. This study shows that the variability in bioavailability of CNM-adsorbed PAHs is largely driven by PAH size, configuration and surface area coverage.

The road for nanomaterials industry: a review of carbon nanotube production, post-treatment, and bulk applications for composites and energy storage.

Science.gov (United States)

Zhang, Qiang; Huang, Jia-Qi; Qian, Wei-Zhong; Zhang, Ying-Ying; Wei, Fei

2013-04-22

The innovation on the low dimensional nanomaterials brings the rapid growth of nano community. Developing the controllable production and commercial applications of nanomaterials for sustainable society is highly concerned. Herein, carbon nanotubes (CNTs) with sp(2) carbon bonding, excellent mechanical, electrical, thermal, as well as transport properties are selected as model nanomaterials to demonstrate the road of nanomaterials towards industry. The engineering principles of the mass production and recent progress in the area of CNT purification and dispersion are described, as well as its bulk application for nanocomposites and energy storage. The environmental, health, and safety considerations of CNTs, and recent progress in CNT commercialization are also included. With the effort from the CNT industry during the past 10 years, the price of multi-walled CNTs have decreased from 45 000 to 100 $ kg(-1) and the productivity increased to several hundred tons per year for commercial applications in Li ion battery and nanocomposites. When the prices of CNTs decrease to 10 $ kg(-1) , their applications as composites and conductive fillers at a million ton scale can be anticipated, replacing conventional carbon black fillers. Compared with traditional bulk chemicals, the controllable synthesis and applications of CNTs on a million ton scale are still far from being achieved due to the challenges in production, purification, dispersion, and commercial application. The basic knowledge of growth mechanisms, efficient and controllable routes for CNT production, the environmental and safety issues, and the commercialization models are still inadequate. The gap between the basic scientific research and industrial development should be bridged by multidisciplinary research for the rapid growth of CNT nano-industry. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Corrosion protection and control using nanomaterials

CERN Document Server

Cook, R

2012-01-01

This book covers the use of nanomaterials to prevent corrosion. The first section deals with the fundamentals of corrosion prevention using nanomaterials. Part two includes a series of case studies and applications of nanomaterials for corrosion control.$bCorrosion is an expensive and potentially dangerous problem in many industries. The potential application of different nanostructured materials in corrosion protection, prevention and control is a subject of increasing interest. Corrosion protection and control using nanomaterials explores the potential use of nanotechnology in corrosion control. The book is divided into two parts. Part one looks at the fundamentals of corrosion behaviour and the manufacture of nanocrystalline materials. Chapters discuss the impact of nanotechnology in reducing corrosion cost, and investigate the influence of various factors including thermodynamics, kinetics and grain size on the corrosion behaviour of nanocrystalline materials. There are also chapters on electrodeposition ...

Sunlight-induced Transformations of Graphene-based Nanomaterials in Aquatic Environments

Science.gov (United States)

Graphene-based nanomaterials and other related carbon nanomaterials (CNMs) can be released from products during their life cycles. Upon entry into aquatic environments, they are potentially transformed by photochemical reactions, oxidation reactions and biological processes, all ...

Superior piezoelectric composite films: taking advantage of carbon nanomaterials.

Science.gov (United States)

Saber, Nasser; Araby, Sherif; Meng, Qingshi; Hsu, Hung-Yao; Yan, Cheng; Azari, Sara; Lee, Sang-Heon; Xu, Yanan; Ma, Jun; Yu, Sirong

2014-01-31

Piezoelectric composites comprising an active phase of ferroelectric ceramic and a polymer matrix have recently found numerous sensory applications. However, it remains a major challenge to further improve their electromechanical response for advanced applications such as precision control and monitoring systems. We here investigated the incorporation of graphene platelets (GnPs) and multi-walled carbon nanotubes (MWNTs), each with various weight fractions, into PZT (lead zirconate titanate)/epoxy composites to produce three-phase nanocomposites. The nanocomposite films show markedly improved piezoelectric coefficients and electromechanical responses (50%) besides an enhancement of ~200% in stiffness. The carbon nanomaterials strengthened the impact of electric field on the PZT particles by appropriately raising the electrical conductivity of the epoxy. GnPs have been proved to be far more promising in improving the poling behavior and dynamic response than MWNTs. The superior dynamic sensitivity of GnP-reinforced composite may be caused by the GnPs' high load transfer efficiency arising from their two-dimensional geometry and good compatibility with the matrix. The reduced acoustic impedance mismatch resulting from the improved thermal conductance may also contribute to the higher sensitivity of GnP-reinforced composite. This research pointed out the potential of employing GnPs to develop highly sensitive piezoelectric composites for sensing applications.

Superior piezoelectric composite films: taking advantage of carbon nanomaterials

International Nuclear Information System (INIS)

Saber, Nasser; Araby, Sherif; Meng, Qingshi; Hsu, Hung-Yao; Lee, Sang-Heon; Ma, Jun; Yan, Cheng; Xu, Yanan; Azari, Sara; Yu, Sirong

2014-01-01

Piezoelectric composites comprising an active phase of ferroelectric ceramic and a polymer matrix have recently found numerous sensory applications. However, it remains a major challenge to further improve their electromechanical response for advanced applications such as precision control and monitoring systems. We here investigated the incorporation of graphene platelets (GnPs) and multi-walled carbon nanotubes (MWNTs), each with various weight fractions, into PZT (lead zirconate titanate)/epoxy composites to produce three-phase nanocomposites. The nanocomposite films show markedly improved piezoelectric coefficients and electromechanical responses (50%) besides an enhancement of ∼200% in stiffness. The carbon nanomaterials strengthened the impact of electric field on the PZT particles by appropriately raising the electrical conductivity of the epoxy. GnPs have been proved to be far more promising in improving the poling behavior and dynamic response than MWNTs. The superior dynamic sensitivity of GnP-reinforced composite may be caused by the GnPs’ high load transfer efficiency arising from their two-dimensional geometry and good compatibility with the matrix. The reduced acoustic impedance mismatch resulting from the improved thermal conductance may also contribute to the higher sensitivity of GnP-reinforced composite. This research pointed out the potential of employing GnPs to develop highly sensitive piezoelectric composites for sensing applications. (paper)

γ-Fe_2O_3 magnetic nanoparticle functionalized with carboxylated multi walled carbon nanotube: Synthesis, characterization, analytical and biomedical application

International Nuclear Information System (INIS)

Kılınç, Ersin

2016-01-01

In recent years, magnetic nanoparticles attained special interest in nanobiotechnology and nanomedicine due to their uniqe properties and biocompatibilities. From this perspective, hybride nanostructure composed from γ-Fe_2O_3 magnetic nanoparticle and carboxylated multi walled carbon nanotube was synthesized and characterized by FT-IR, VSM, SEM, HR-TEM and ICP-OES. Microscopy images showed that magnetic nanoparticles were nearly spherical structure that arranged on the axis of carboxylated MWCNT. Particle size was found lower than 10 nm. VSM results showed that the obtained magnetic nanoparticles presented superparamagnetic properties at room temperature. The magnetic saturation value was determined as 35.2 emu/g. It was used for the adsorption and controlled release of harmane, a potent tremor-producing neurotoxin. Maximum adsorption capacity was calculated as 151.5 mg/g from Langmuir isotherm. Concentration of harmane was determined by HPLC with fluorescence detection. The antimicrobial activity of synthesized magnetic nanoparticle was investigated against gram-negative and gram-positive bacteria. However, no activity was observed. - Highlights: • A nanomaterial from gamma iron oxide and multi walled carbon nanotube was synthesized. • It was characterized and microstructure was investigated. • No antimicrobial activity was observed. • Adsorption and release of harmane on its were examined.

Modeling Engineered Nanomaterials (ENMs) Fate and ...

Science.gov (United States)

Under the Toxic Substances Control Act (TSCA), the Environmental Protection Agency (EPA) is required to perform new chemical reviews of engineered nanomaterials (ENMs) identified in pre-manufacture notices. However, environmental fate models developed for traditional contaminants are limited in their ability to simulate the environmental behavior of nanomaterials due to incomplete understanding and representation of the processes governing nanomaterial distribution in the environment and by scarce empirical data quantifying the interaction of nanomaterials with environmental surfaces. We have updated the Water Quality Analysis Simulation Program (WASP), version S, to incorporate nanomaterials as an explicitly simulated state variable. WASPS now has the capability to simulate nanomaterial fate and transport in surface waters and sediments using heteroaggregation, the kinetic process governing the attachment of nanomaterials to particles and subsequently ENM distribution in the aqueous and sediment phases. Unlike dissolved chemicals which use equilibrium partition coefficients, heteroaggregation consists of a particle collision rate and an attachment efficiency ( lXhet) that generally acts as a one direction process. To demonstrate, we used a derived a het value from sediment attachment studies to parameterize WASP for simulation of multi walled carbon nanotube (MWCNT) transport in Brier Creek, a coastal plain river located in central eastern Georgia, USA and a tr

Magnetic properties of magnetic glass-like carbon prepared from furan resin alloyed with magnetic fluid

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Kazumasa, E-mail: naka@sss.fukushima-u.ac.jp [Materials Science Area, Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Okuyama, Kyoko [Materials Science Area, Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Takase, Tsugiko [Institute of Environmental Radioactivity (IER), Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan)

2017-03-01

Magnetic glass-like carbons that were heat-treated at different temperatures or were filled with different magnetic nanoparticle contents were prepared from furan resin alloyed with magnetic fluid (MF) or Fe{sub 3}O{sub 4} powder in their liquid-phase states during mixing. Compared to the Fe{sub 3}O{sub 4} powder-alloyed carbon, the MF-alloyed carbon has highly dispersed the nanoparticles, and has the excellent saturation magnetization and coercivity. It is implied that saturation magnetizations are related to changes in the types of phases for the nanoparticles and the relative intensities of X-ray diffraction peaks for iron and iron-containing compounds in the carbons. Additionally, the coercivities are possibly affected by the size and crystallinity of the nanoparticles, the relative amounts of iron, and the existence of amorphous compounds on the carbon surfaces. - Highlights: • Magnetic glass-like carbons were prepared from furan resin alloyed with magnetic fluid. • The nanoparticles of MF-alloyed GLCs were highly dispersed. • MF-alloyed GLCs had excellent magnetic properties compared to powder-alloyed ones. • The magnetic properties changed with treatment temperature and nanoparticle content. • The changes in magnetic properties were investigated with XRD and FE-SEM.

Stimuli responsive nanomaterials for controlled release applications

KAUST Repository

Li, Song

2012-01-01

The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. Coupled with excellent biocompatibility profiles, various nanomaterials have showed great promise for biomedical applications. Stimuli-responsive nanomaterials guarantee the controlled release of cargo to a given location, at a specific time, and with an accurate amount. In this review, we have combined the major stimuli that are currently used to achieve the ultimate goal of controlled and targeted release by "smart" nanomaterials. The most heavily explored strategies include (1) pH, (2) enzymes, (3) redox, (4) magnetic, and (5) light-triggered release.

Synthesis, surface modification/decoration of luminescent–magnetic core/shell nanomaterials, based on the lanthanide doped fluorides (Fe3O4/SiO2/NH2/PAA/LnF3)

International Nuclear Information System (INIS)

Runowski, Marcin; Lis, Stefan

2016-01-01

The synthesized magnetite nanoparticles (10–15 nm) were successfully coated with amine modified silica nanoshell, which led to the formation of core/shell type nanostructures (30–50 nm). The as-prepared nanoparticles were surface modified with polyacrylic acid (PAA) via electrostatic interactions of –NH 2 and –COOH groups. Afterwards, the surface PAA molecules acted as complexing agents of the introduced lanthanide (Ln 3+ ) ions. Subsequently, the as-prepared nanostructures were surface decorated with luminescent LnF 3 nanoparticles, forming Eu 3+ or Tb 3+ doped Fe 3 O 4 /SiO 2 /NH 2 /PAA/LnF 3 nanomaterials (50–100 nm). The obtained luminescent–magnetic products exhibited simultaneously bright red or green emission under UV lamp irradiation (λ ex =254 nm), and a response for the applied magnetic field (strong magnet attracts the colloidal particles, dispersed in aqueous medium). After the synthesis, properties of the nanomaterials were investigated by powder X-ray diffraction (XRD) technique, transmission electron microscopy (TEM), infrared spectroscopy (IR) and spectrofluorometry (analysis of excitation/emission spectra and luminescence decay curves). Such advanced nanomaterials can be potentially used in multimodal imaging, targeted therapies and as multifunctional contrast agents, novel luminescent–magnetic tracers, protection of documents, etc. - Highlights: • Luminescent–magnetic nanomaterials Fe 3 O 4 /SiO 2 /NH 2 /PAA/LnF 3 were synthesized. • Core/shell nanostructures were obtained by surface modification of nanoparticles. • Luminescent lanthanide fluoride nanoparticles doped with Eu 3+ and Tb 3+ ions. • Multifunctional core/shell nanostructures exhibited red or green emission. • Nanomaterials formed stable aqueous colloids.

Synthesis, photophysical analysis, and in vitro cytotoxicity assessment of the multifunctional (magnetic and luminescent) core@shell nanomaterial based on lanthanide-doped orthovanadates

Energy Technology Data Exchange (ETDEWEB)

Szczeszak, Agata [Adam Mickiewicz University, Department of Rare Earths, Faculty of Chemistry (Poland); Ekner-Grzyb, Anna [Adam Mickiewicz University, Department of Behavioural Ecology, Faculty of Biology (Poland); Runowski, Marcin [Adam Mickiewicz University, Department of Rare Earths, Faculty of Chemistry (Poland); Mrówczyńska, Lucyna [Adam Mickiewicz University, Department of Cell Biology, Faculty of Biology (Poland); Grzyb, Tomasz; Lis, Stefan, E-mail: blis@amu.edu.pl [Adam Mickiewicz University, Department of Rare Earths, Faculty of Chemistry (Poland)

2015-03-15

Rare earths orthovanadates (REVO{sub 4}) doped with luminescent lanthanide ions (Ln{sup 3+}) play an important role as promising light-emitting materials. Gadolinium orthovanadate exhibits strong absorption of ultraviolet radiation and as a matrix doped with Eu{sup 3+} ions is well known for its efficient and intense red emission, induced by energy transfer from the VO{sub 4}{sup 3−} groups to Eu{sup 3+} ions. In the presented study, Fe{sub 3}O{sub 4}@SiO{sub 2}@GdVO{sub 4}:Eu{sup 3+} 5 % nanomaterial was investigated. The core@shell structures demonstrate attractive properties, such as higher thermal stability, enhanced water solubility, increased optical response, higher luminescence, longer decay times, and magnetic properties. Silica coating may protect nanocrystals from the surrounding environment. Therefore, such silica-covered nanoparticles (NPs) are successfully utilized in biomedical research. Multifunctional magnetic nanophosphors are very interesting due to their potential biomedical applications such as magnetic resonance imaging, hyperthermic treatment, and drug delivery. Therefore, the aim of our study was to investigate photophysical, chemical, and biological properties of multifunctional REVO{sub 4} doped with Ln{sup 3+}. Moreover, the studied NPs did not affect erythrocyte sedimentation rate, cell membrane permeability, and morphology of human red blood cells.

Kinetic enhancement via passive deposition of carbon-based nanomaterials in vanadium redox flow batteries

Science.gov (United States)

Aaron, Doug; Yeom, Sinchul; Kihm, Kenneth D.; Ashraf Gandomi, Yasser; Ertugrul, Tugrul; Mench, Matthew M.

2017-10-01

Addition of carbon-based nanomaterials to operating flow batteries accomplishes vanadium redox flow battery performance improvement. Initial efforts focus on addition of both pristine graphene and vacuum-filtered reduced graphene oxide (rGO) film on carbon paper supporting electrodes. While the former is unable to withstand convective flow through the porous electrode, the latter shows measurable kinetic improvement, particularly when laid on the polymer electrolyte membrane (PEM) side of the electrode; in contrast to the kinetic performance gain, a deleterious impact on mass transport is observed. Based on this tradeoff, further improvement is realized using perforated rGO films placed on the PEM side of the electrodes. Poor mass transport in the dense rGO film prompts identification of a more uniform, passive deposition method. A suspension of rGO flakes or Vulcan carbon black (XC-72R), both boasting two orders-of-magnitude greater specific surface area than that of common carbon electrodes, is added to the electrolyte reservoirs and allowed to passively deposit on the carbon paper or carbon felt supporting electrodes. For common carbon felt electrodes, addition of rGO flakes or XC-72R enables a tripling of current density at the same 80% voltage efficiency.

Nanomaterials for fuel cell catalysis

CSIR Research Space (South Africa)

Ozoemena, KI

2016-01-01

Full Text Available Global experts provide an authoritative source of information on the use of electrochemical fuel cells, and in particular discuss the use of nanomaterials to enhance the performance of existing energy systems. The book covers the state of the art...

Toxicology and cellular effect of manufactured nanomaterials

Science.gov (United States)

Chen, Fanqing

2014-07-22

The increasing use of nanotechnology in consumer products and medical applications underlies the importance of understanding its potential toxic effects to people and the environment. Herein are described methods and assays to predict and evaluate the cellular effects of nanomaterial exposure. Exposing cells to nanomaterials at cytotoxic doses induces cell cycle arrest and increases apoptosis/necrosis, activates genes involved in cellular transport, metabolism, cell cycle regulation, and stress response. Certain nanomaterials induce genes indicative of a strong immune and inflammatory response within skin fibroblasts. Furthermore, the described multiwall carbon nanoonions (MWCNOs) can be used as a therapeutic in the treatment of cancer due to its cytotoxicity.

Continuous production of fullerenes and other carbon nanomaterials on a semi-industrial scale using plasma technology

International Nuclear Information System (INIS)

Gruenberger, T.M.; Gonzalez-Aguilar, J.; Fulcheri, L.; Fabry, F.; Grivei, E.; Probst, N.; Flamant, G.; Charlier, J.-C.

2002-01-01

A new production method is presented allowing the production of bulk quantities of fullerenes and other carbon nanomaterials using a 3-phase thermal plasma (260 kW). The main characteristics of this method lie in the independent control of the carbon throughput by injection of a solid carbon feedstock, and the immediate extraction of the synthesised product from the reactor, allowing production on a continuous basis. The currently investigated plasma facility is of an intermediate scale between lab-size and an industrial pilot plant, ready for further up scaling to an industrial size. The influence of a large number of different carbon precursors, plasma gases and operating conditions on the fullerene yield has been studied. At this state, quantities of up to 1 kg of carbon can be processed per hour with further scope for increase, leading to production rates for this type of materials not achievable with any other technology at present

γ-Fe{sub 2}O{sub 3} magnetic nanoparticle functionalized with carboxylated multi walled carbon nanotube: Synthesis, characterization, analytical and biomedical application

Energy Technology Data Exchange (ETDEWEB)

Kılınç, Ersin, E-mail: kilincersin@gmail.com

2016-03-01

In recent years, magnetic nanoparticles attained special interest in nanobiotechnology and nanomedicine due to their uniqe properties and biocompatibilities. From this perspective, hybride nanostructure composed from γ-Fe{sub 2}O{sub 3} magnetic nanoparticle and carboxylated multi walled carbon nanotube was synthesized and characterized by FT-IR, VSM, SEM, HR-TEM and ICP-OES. Microscopy images showed that magnetic nanoparticles were nearly spherical structure that arranged on the axis of carboxylated MWCNT. Particle size was found lower than 10 nm. VSM results showed that the obtained magnetic nanoparticles presented superparamagnetic properties at room temperature. The magnetic saturation value was determined as 35.2 emu/g. It was used for the adsorption and controlled release of harmane, a potent tremor-producing neurotoxin. Maximum adsorption capacity was calculated as 151.5 mg/g from Langmuir isotherm. Concentration of harmane was determined by HPLC with fluorescence detection. The antimicrobial activity of synthesized magnetic nanoparticle was investigated against gram-negative and gram-positive bacteria. However, no activity was observed. - Highlights: • A nanomaterial from gamma iron oxide and multi walled carbon nanotube was synthesized. • It was characterized and microstructure was investigated. • No antimicrobial activity was observed. • Adsorption and release of harmane on its were examined.

Pd nanoparticles encapsulated in magnetic carbon nanocages: an efficient nanoenzyme for the selective detection and multicolor imaging of cancer cells

Science.gov (United States)

Chen, Gaosong; Song, Jingjing; Zhang, Haoli; Jiang, Yuntian; Liu, Weisheng; Zhang, Wei; Wang, Baodui

2015-08-01

Rapid and simple molecular recognition based techniques for the identification of the subtypes of cancer cells are essential in molecular medicine. However, improving the sensitivity and accuracy of the early diagnosis of this disease remains a major challenge. Herein, we develop a novel approach for the in situ growth of palladium nanoparticles in magnetic carbon nanocages (PdNPs/MCNCs). The confined Pd NPs, which have excellent dispersion in magnetic carbon nanocages, show superior catalytic performance for the cleavage reaction of N-butyl-4-NHAlloc-1,8-naphthalimide (NNPH), thereby producing significant changes in both color (from colorless to jade-green) and fluorescence (from blue to green) through the ICT process. Based on the abovementioned results, a novel sensing platform utilizing the PdNPs/MCNC nanocatalyst as an artificial enzyme and NNPH as a fluorescent and color change reporter molecule for the multicolor imaging and colorimetric detection of cancer cells was developed. We envision that this nanomaterial can be used as a power tool for a wide range of potential applications in biotechnology and medicine.Rapid and simple molecular recognition based techniques for the identification of the subtypes of cancer cells are essential in molecular medicine. However, improving the sensitivity and accuracy of the early diagnosis of this disease remains a major challenge. Herein, we develop a novel approach for the in situ growth of palladium nanoparticles in magnetic carbon nanocages (PdNPs/MCNCs). The confined Pd NPs, which have excellent dispersion in magnetic carbon nanocages, show superior catalytic performance for the cleavage reaction of N-butyl-4-NHAlloc-1,8-naphthalimide (NNPH), thereby producing significant changes in both color (from colorless to jade-green) and fluorescence (from blue to green) through the ICT process. Based on the abovementioned results, a novel sensing platform utilizing the PdNPs/MCNC nanocatalyst as an artificial enzyme and NNPH

A Reference Searching Related To Nanomaterials,Food Packaging and Sustainability

OpenAIRE

Tonnie, Aruoture Onome

2007-01-01

This report focuses on the study of nanomaterials as a packaging material for the food industries. Reviews were carried out and the various properties exhibited by various nanomaterial used in the packaging industry were looked into. An investigation was also done on carbon nanotubes which are used to a large extent as reinforcing materials in the development of new class of nanocomposites. This report also traces the cause of sustainability problems associated with the use of nanomaterials i...

Nanomaterials for electrochemical sensing and biosensing

CERN Document Server

Pumera, Martin

2014-01-01

Part 1: Nanomaterial-Based ElectrodesCarbon Nanotube-Based Electrochemical Sensors and Biosensors, Martin Pumera, National Institute for Materials Science, JapanElectrochemistry on Single Carbon Nanotube, Pat Collier, Caltech, USATheory of Voltammetry at Nanoparticle-Modified Electrodes, Richard G. Compton, Oxford University, UKMetal Oxide Nanoparticle-Modified Electrodes, Frank Marken, University of Bath, UKSemiconductor Quantum Dots for Electrochemical Bioanalysis, Eugenii Katz, Clarkson University, USAN

Cellulosic Nanomaterials in Food and Nutraceutical Applications: A Review.

Science.gov (United States)

Khan, Avik; Wen, Yangbing; Huq, Tanzina; Ni, Yonghao

2018-01-10

Cellulosic nanomaterials (CNMs) are organic, green nanomaterials that are obtained from renewable sources and possess exceptional mechanical strength and biocompatibility. The associated unique physical and chemical properties have made these nanomaterials an intriguing prospect for various applications including the food and nutraceutical industry. From the immobilization of various bioactive agents and enzymes, emulsion stabilization, direct food additives, to the development of intelligent packaging systems or pathogen or pH detectors, the potential food related applications for CNMs are endless. Over the past decade, there have been several reviews published covering different aspects of cellulosic nanomaterials, such as processing-structure-property relationship, physical and chemical properties, rheology, extraction, nanocomposites, etc. In this critical review, we have discussed and provided a summary of the recent developments in the utilization of cellulosic nanomaterials in applications related to food and nutraceuticals.

Effects of Engineered Nanomaterials on Plants Growth: An Overview

Science.gov (United States)

Bagheri, Samira; Muhd Julkapli, Nurhidayatullaili; Juraimi, Abdul Shukor; Hashemi, Farahnaz Sadat Golestan

2014-01-01

Rapid development and wide applications of nanotechnology brought about a significant increment on the number of engineered nanomaterials (ENs) inevitably entering our living system. Plants comprise of a very important living component of the terrestrial ecosystem. Studies on the influence of engineered nanomaterials (carbon and metal/metal oxides based) on plant growth indicated that in the excess content, engineered nanomaterials influences seed germination. It assessed the shoot-to-root ratio and the growth of the seedlings. From the toxicological studies to date, certain types of engineered nanomaterials can be toxic once they are not bound to a substrate or if they are freely circulating in living systems. It is assumed that the different types of engineered nanomaterials affect the different routes, behavior, and the capability of the plants. Furthermore, different, or even opposing conclusions, have been drawn from most studies on the interactions between engineered nanomaterials with plants. Therefore, this paper comprehensively reviews the studies on the different types of engineered nanomaterials and their interactions with different plant species, including the phytotoxicity, uptakes, and translocation of engineered nanomaterials by the plant at the whole plant and cellular level. PMID:25202734

Nanomaterial release characteristics in a single-walled carbon nanotube manufacturing workplace

International Nuclear Information System (INIS)

Ji, Jun Ho; Kim, Jong Bum; Lee, Gwangjae; Bae, Gwi-Nam

2015-01-01

As carbon nanotubes (CNTs) are widely used in various applications, exposure assessment also increases in importance with other various toxicity tests for CNTs. We conducted 24-h continuous nanoaerosol measurements to identify possible nanomaterial release in a single-walled carbon nanotube (SWCNT) manufacturing workplace. Four real-time aerosol instruments were used to determine the nanosized and microsized particle numbers, particle surface area, and carbonaceous species. Task-based exposure assessment was carried out for SWCNT synthesis using the arc plasma and thermal decomposition processes to remove amorphous carbon components as impurities. During the SWCNT synthesis, the black carbon (BC) concentration was 2–12 μg/m 3 . The maximum BC mass concentrations occurred when the synthesis chamber was opened for harvesting the SWCNTs. The number concentrations of particles with sizes 10–420 nm were 10,000–40,000 particles/cm 3 during the tasks. The maximum number concentration existed when a vacuum pump was operated to remove exhaust air from the SWCNT synthesis chamber due to the penetration of highly concentrated oil mists through the window opened. We analyzed the particle mass size distribution and particle number size distribution for each peak episode. Using real-time aerosol detectors, we distinguished the SWCNT releases from background nanoaerosols such as oil mist and atmospheric photochemical smog particles. SWCNT aggregates with sizes of 1–10 μm were mainly released from the arc plasma synthesis. The harvesting process was the main release route of SWCNTs in the workplace

Nanomaterial release characteristics in a single-walled carbon nanotube manufacturing workplace

Energy Technology Data Exchange (ETDEWEB)

Ji, Jun Ho [EcoPictures Co., Ltd (Korea, Republic of); Kim, Jong Bum; Lee, Gwangjae; Bae, Gwi-Nam, E-mail: gnbae@kist.re.kr [Korea Institute of Science and Technology, Center for Environment, Health and Welfare Research (Korea, Republic of)

2015-02-15

As carbon nanotubes (CNTs) are widely used in various applications, exposure assessment also increases in importance with other various toxicity tests for CNTs. We conducted 24-h continuous nanoaerosol measurements to identify possible nanomaterial release in a single-walled carbon nanotube (SWCNT) manufacturing workplace. Four real-time aerosol instruments were used to determine the nanosized and microsized particle numbers, particle surface area, and carbonaceous species. Task-based exposure assessment was carried out for SWCNT synthesis using the arc plasma and thermal decomposition processes to remove amorphous carbon components as impurities. During the SWCNT synthesis, the black carbon (BC) concentration was 2–12 μg/m{sup 3}. The maximum BC mass concentrations occurred when the synthesis chamber was opened for harvesting the SWCNTs. The number concentrations of particles with sizes 10–420 nm were 10,000–40,000 particles/cm{sup 3} during the tasks. The maximum number concentration existed when a vacuum pump was operated to remove exhaust air from the SWCNT synthesis chamber due to the penetration of highly concentrated oil mists through the window opened. We analyzed the particle mass size distribution and particle number size distribution for each peak episode. Using real-time aerosol detectors, we distinguished the SWCNT releases from background nanoaerosols such as oil mist and atmospheric photochemical smog particles. SWCNT aggregates with sizes of 1–10 μm were mainly released from the arc plasma synthesis. The harvesting process was the main release route of SWCNTs in the workplace.

Emerging roles of engineered nanomaterials in the food industry.

Science.gov (United States)

Morris, V J

2011-10-01

Nanoscience is the study of phenomena and the manipulation of materials at the atomic or molecular level. Nanotechnology involves the design, production and use of structures through control of the size and shape of the materials at the nanometre scale. Nanotechnology in the food sector is an emerging area with considerable research and potential products. There is particular interest in the definition and regulation of engineered nanomaterials. This term covers three classes of nanomaterials: natural and processed nanostructures in foods; particulate nanomaterials metabolized or excreted on digestion; and particulate nanomaterials not broken down on digestion, which accumulate in the body. This review describes examples of these classes and their likely status in the food industry. Copyright © 2011 Elsevier Ltd. All rights reserved.

Diagnostics Strategies with Electrochemical Affinity Biosensors Using Carbon Nanomaterials as Electrode Modifiers

Science.gov (United States)

Campuzano, Susana; Yáñez-Sedeño, Paloma; Pingarrón, José M.

2016-01-01

Early diagnosis is often the key to successful patient treatment and survival. The identification of various disease signaling biomarkers which reliably reflect normal and disease states in humans in biological fluids explain the burgeoning research field in developing new methodologies able to determine the target biomarkers in complex biological samples with the required sensitivity and selectivity and in a simple and rapid way. The unique advantages offered by electrochemical sensors together with the availability of high affinity and specific bioreceptors and their great capabilities in terms of sensitivity and stability imparted by nanostructuring the electrode surface with different carbon nanomaterials have led to the development of new electrochemical biosensing strategies that have flourished as interesting alternatives to conventional methodologies for clinical diagnostics. This paper briefly reviews the advantages of using carbon nanostructures and their hybrid nanocomposites as electrode modifiers to construct efficient electrochemical sensing platforms for diagnosis. The review provides an updated overview of some selected examples involving attractive amplification and biosensing approaches which have been applied to the determination of relevant genetic and protein diagnostics biomarkers. PMID:28035946

Side-by-side comparison of Raman spectra of anchored and suspended carbon nanomaterials

International Nuclear Information System (INIS)

Sidorov, Anton N; Pabba, Santosh; Cohn, Robert W; Sumanasekera, G U; Hewaparakrama, Kapila P

2008-01-01

Raman spectra of ordered carbon nanomaterials are quite sensitive to surface perturbations, including trace residues, structural defects and residual stress. This is demonstrated by a series of experiments with carbon nanotubes and graphene. Their spectra change due to subtle changes in preparation and attachment to the substrate and to each other. Differences are most clearly seen by forming a material into an air bridge and probing it in the air gap and at the anchor points. A monolayer graphene sheet, shows a larger disorder band at the anchor points than in the air gap. However, a bundle or rope of parallel-aligned single-wall nanotubes shows a larger disorder band in the gap than at the anchor points. For the graphene sheet the substrate surface deforms the graphene, leading to increases in the disorder band. For the rope, the close proximity of the nanotubes to each other appears to produce a larger stress than the rope resting on the substrate

Carbon black vs. black carbon and other airborne materials containing elemental carbon: Physical and chemical distinctions

International Nuclear Information System (INIS)

Long, Christopher M.; Nascarella, Marc A.; Valberg, Peter A.

2013-01-01

Airborne particles containing elemental carbon (EC) are currently at the forefront of scientific and regulatory scrutiny, including black carbon, carbon black, and engineered carbon-based nanomaterials, e.g., carbon nanotubes, fullerenes, and graphene. Scientists and regulators sometimes group these EC-containing particles together, for example, interchangeably using the terms carbon black and black carbon despite one being a manufactured product with well-controlled properties and the other being an undesired, incomplete-combustion byproduct with diverse properties. In this critical review, we synthesize information on the contrasting properties of EC-containing particles in order to highlight significant differences that can affect hazard potential. We demonstrate why carbon black should not be considered a model particle representative of either combustion soots or engineered carbon-based nanomaterials. Overall, scientific studies need to distinguish these highly different EC-containing particles with care and precision so as to forestall unwarranted extrapolation of properties, hazard potential, and study conclusions from one material to another. -- Highlights: •Major classes of elemental carbon-containing particles have distinct properties. •Despite similar names, carbon black should not be confused with black carbon. •Carbon black is distinguished by a high EC content and well-controlled properties. •Black carbon particles are characterized by their heterogenous properties. •Carbon black is not a model particle representative of engineered nanomaterials. -- This review demonstrates the significant physical and chemical distinctions between elemental carbon-containing particles e.g., carbon black, black carbon, and engineered nanomaterials

Production of nanomaterials: physical and chemical technologies

International Nuclear Information System (INIS)

Giorgi, Leonardo; Salernitano, Elena

2015-01-01

Are define nanomaterials those materials which have at least one dimension in the range between 1 and 100 nm. By the term nanotechnology refers, instead, to the study of phenomena and manipulation of materials at the atomic and molecular level. The materials brought to the nanometric dimensions take particular chemical-physical properties different from the corresponding conventional macro materials. Speaking about the structure of nanoscale, you can check some basic properties materials (eg. Melting temperature, magnetic and electrical properties) without changing its chemical composition. In this perspective are crucial knowledge and control of production processes in order to design and get the nanomaterial more suitable for a specific application. For this purpose, it describes a series of processes of production of nanomaterials with application examples. [it

Spatio-temporal change in forest cover and carbon storage considering actual and potential forest cover in South Korea.

Science.gov (United States)

Nam, Kijun; Lee, Woo-Kyun; Kim, Moonil; Kwak, Doo-Ahn; Byun, Woo-Hyuk; Yu, Hangnan; Kwak, Hanbin; Kwon, Taesung; Sung, Joohan; Chung, Dong-Jun; Lee, Seung-Ho

2015-07-01

This study analyzes change in carbon storage by applying forest growth models and final cutting age to actual and potential forest cover for six major tree species in South Korea. Using National Forest Inventory data, the growth models were developed to estimate mean diameter at breast height, tree height, and number of trees for Pinus densiflora, Pinus koraiensis, Pinus rigida, Larix kaempferi, Castanea crenata and Quercus spp. stands. We assumed that actual forest cover in a forest type map will change into potential forest covers according to the Hydrological and Thermal Analogy Groups model. When actual forest cover reaches the final cutting age, forest volume and carbon storage are estimated by changed forest cover and its growth model. Forest volume between 2010 and 2110 would increase from 126.73 to 157.33 m(3) hm(-2). Our results also show that forest cover, volume, and carbon storage could abruptly change by 2060. This is attributed to the fact that most forests are presumed to reach final cutting age. To avoid such dramatic change, a regeneration and yield control scheme should be prepared and implemented in a way that ensures balance in forest practice and yield.

Nanomaterials for membrane fouling control: accomplishments and challenges.

Science.gov (United States)

Yang, Qian; Mi, Baoxia

2013-11-01

We report a review of recent research efforts on incorporating nanomaterials-including metal/metal oxide nanoparticles, carbon-based nanomaterials, and polymeric nanomaterials-into/onto membranes to improve membrane antifouling properties in biomedical or potentially medical-related applications. In general, nanomaterials can be incorporated into/onto a membrane by blending them into membrane fabricating materials or by attaching them to membrane surfaces via physical or chemical approaches. Overall, the fascinating, multifaceted properties (eg, high hydrophilicity, superparamagnetic properties, antibacterial properties, amenable functionality, strong hydration capability) of nanomaterials provide numerous novel strategies and unprecedented opportunities to fully mitigate membrane fouling. However, there are still challenges in achieving a broader adoption of nanomaterials in the membrane processes used for biomedical applications. Most of these challenges arise from the concerns over their long-term antifouling performance, hemocompatibility, and toxicity toward humans. Therefore, rigorous investigation is still needed before the adoption of some of these nanomaterials in biomedical applications, especially for those nanomaterials proposed to be used in the human body or in contact with living tissue/body fluids for a long period of time. Nevertheless, it is reasonable to predict that the service lifetime of membrane-based biomedical devices and implants will be prolonged significantly with the adoption of appropriate fouling control strategies. Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Alternative mannosylation method for nanomaterials: application to oxidized debris-free multiwalled carbon nanotubes

International Nuclear Information System (INIS)

Sousa, Marcelo de; Martinez, Diego Stéfani Teodoro; Alves, Oswaldo Luiz

2016-01-01

Mannosylation is a method commonly used to deliver nanomaterials to specific organs and tissues via cellular macrophage uptake. In this work, for the first time, we proposed a method that involves the binding of d-mannose to ethylenediamine to form mannosylated ethylenediamine, which is then coupled to oxidized and purified multiwalled carbon nanotubes. The advantage of this approach is that mannosylated ethylenediamine precipitates in methanol, which greatly facilitates the separation of this product in the synthesis process. Carbon nanotubes were oxidized using concentrated H_2SO_4 and HNO_3 by conventional reflux method. However, during this oxidation process, carbon nanotubes generated carboxylated carbonaceous fragments (oxidation debris). These by-products were removed from the oxidized carbon nanotubes to ensure that the functionalization would occur only on the carbon nanotube surface. The coupling of mannosylated ethylenediamine to debris-free carbon nanotubes was accomplished using n-(3-dimethylaminopropyl)-n-ethylcarbodiimide and n-hydroxysuccinimide. Deconvoluted N1s spectra obtained from X-ray photoelectron spectroscopy gave binding energies of 399.8 and 401.7 eV, which we attributed to the amide and amine groups, respectively, of carbon nanotubes functionalized with mannosylated ethylenediamine. Deconvoluted O1s spectra showed a binding energy of 532.4 eV, which we suggest is caused by an overlap in the binding energies of the aliphatic CO groups of d-mannose and the O=C group of the amide bond. The functionalization degree was approximately 3.4 %, according to the thermogravimetric analysis. Scanning electron microscopy demonstrated that an extended carbon nanotube morphology was preserved following the oxidation, purification, and functionalization steps.

Alternative mannosylation method for nanomaterials: application to oxidized debris-free multiwalled carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Sousa, Marcelo de, E-mail: marcelosousap2@yahoo.com.br [University of Campinas (Unicamp), Solid State Chemistry Laboratory (LQES) and NanoBioss Laboratory, Institute of Chemistry (Brazil); Martinez, Diego Stéfani Teodoro, E-mail: diego.martinez@lnnano.cnpem.br [Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian Nanotechnology National Laboratory (LNNano) (Brazil); Alves, Oswaldo Luiz, E-mail: oalves@iqm.unicamp.br [University of Campinas (Unicamp), Solid State Chemistry Laboratory (LQES) and NanoBioss Laboratory, Institute of Chemistry (Brazil)

2016-06-15

Mannosylation is a method commonly used to deliver nanomaterials to specific organs and tissues via cellular macrophage uptake. In this work, for the first time, we proposed a method that involves the binding of d-mannose to ethylenediamine to form mannosylated ethylenediamine, which is then coupled to oxidized and purified multiwalled carbon nanotubes. The advantage of this approach is that mannosylated ethylenediamine precipitates in methanol, which greatly facilitates the separation of this product in the synthesis process. Carbon nanotubes were oxidized using concentrated H{sub 2}SO{sub 4} and HNO{sub 3} by conventional reflux method. However, during this oxidation process, carbon nanotubes generated carboxylated carbonaceous fragments (oxidation debris). These by-products were removed from the oxidized carbon nanotubes to ensure that the functionalization would occur only on the carbon nanotube surface. The coupling of mannosylated ethylenediamine to debris-free carbon nanotubes was accomplished using n-(3-dimethylaminopropyl)-n-ethylcarbodiimide and n-hydroxysuccinimide. Deconvoluted N1s spectra obtained from X-ray photoelectron spectroscopy gave binding energies of 399.8 and 401.7 eV, which we attributed to the amide and amine groups, respectively, of carbon nanotubes functionalized with mannosylated ethylenediamine. Deconvoluted O1s spectra showed a binding energy of 532.4 eV, which we suggest is caused by an overlap in the binding energies of the aliphatic CO groups of d-mannose and the O=C group of the amide bond. The functionalization degree was approximately 3.4 %, according to the thermogravimetric analysis. Scanning electron microscopy demonstrated that an extended carbon nanotube morphology was preserved following the oxidation, purification, and functionalization steps.

Rapid detection of polyethylene glycol sonolysis upon functionalization of carbon nanomaterials.

Science.gov (United States)

Murali, Vasanth S; Wang, Ruhung; Mikoryak, Carole A; Pantano, Paul; Draper, Rockford

2015-09-01

Polyethylene glycol (PEG) and related polymers are often used in the functionalization of carbon nanomaterials in procedures that involve sonication. However, PEG is very sensitive to sonolytic degradation and PEG degradation products can be toxic to mammalian cells. Thus, it is imperative to assess potential PEG degradation to ensure that the final material does not contain undocumented contaminants that can introduce artifacts into experimental results. Described here is a simple and inexpensive polyacrylamide gel electrophoresis method to detect the sonolytic degradation of PEG. The method was used to monitor the integrity of PEG phospholipid constructs and branched chain PEGs after different sonication times. This approach not only helps detect degraded PEG, but should also facilitate rapid screening of sonication parameters to find optimal conditions that minimize PEG damage. © 2015 by the Society for Experimental Biology and Medicine.

Electron accelerators and nanomaterials - a symbiosis

International Nuclear Information System (INIS)

Dixit, Kavita P.; Mittal, K.C.

2011-01-01

Electron Accelerators and Nanomaterials share a symbiotic relationship. While electron accelerators are fast emerging as popular tools in the field of nanomaterials, use of nanomaterials so developed for sub-systems of accelerators is being explored. Material damage studies, surface modification and lithography in the nanometre scale are some of the areas in which electron accelerators are being extensively used. New methods to characterize the structure of nanoparticles use intense X-ray sources, generated from electron accelerators. Enhancement of field emission properties of carbon nanotubes using electron accelerators is another important area that is being investigated. Research on nanomaterials for use in the field of accelerators is still in the laboratory stage. Yet, new trends and emerging technologies can effectively produce materials which can be of significant use in accelerators. Properties such as enhanced field emission can be put to use in cathodes of electron guns. Superconducting properties some materials may also be useful in accelerators. This paper focusses on the electron accelerators used for synthesis, characterization and property-enhancement of nanomaterials. The details of electron accelerators used for these applications will be highlighted. Some light will be thrown on properties of nano materials which can have potential use in accelerators. (author)

Critical sizes and critical characteristics of nanoclusters, nanostructures and nanomaterials

International Nuclear Information System (INIS)

Suzdalev, I.P.

2005-01-01

Full text: Critical sizes and characteristics of nanoclusters and nanostructures are introduced as the parameters of nanosystems and nanomaterials. The next critical characteristics are considered: atomic and electronic 'magic number', critical size of cluster nucleation, critical size of melting-freezing of cluster, critical size of quantum (laser) radiation, critical sizes for the single electron conductivity, critical energy and magnetic field for the magnetic tunneling, critical cluster sizes for the giant magnetic resistance, critical size of the first order magnetic phase transition. The critical characteristics are estimated by thermodynamic approaches, by Moessbauer spectroscopy, AFM, heat capacity, SQUID magnetometry and other technique, The influence of cluster-cluster interactions, cluster-matrix interactions and cluster defects on cluster atomic dynamics, cluster melting, cluster critical sizes, Curie or Neel points and the character of magnetic phase transitions were investigated. The applications of critical size and critical characteristic parameters for the nanomaterial characterization are considered

Immobilization techniques in the fabrication of nanomaterial-based electrochemical biosensors: a review.

Science.gov (United States)

Putzbach, William; Ronkainen, Niina J

2013-04-11

The evolution of 1st to 3rd generation electrochemical biosensors reflects a simplification and enhancement of the transduction pathway. However, in recent years, modification of the transducer with nanomaterials has become increasingly studied and imparts many advantages. The sensitivity and overall performance of enzymatic biosensors has improved tremendously as a result of incorporating nanomaterials in their fabrication. Given the unique and favorable qualities of gold nanoparticles, graphene and carbon nanotubes as applied to electrochemical biosensors, a consolidated survey of the different methods of nanomaterial immobilization on transducer surfaces and enzyme immobilization on these species is beneficial and timely. This review encompasses modification of enzymatic biosensors with gold nanoparticles, carbon nanotubes, and graphene.

Immobilization Techniques in the Fabrication of Nanomaterial-Based Electrochemical Biosensors: A Review

Directory of Open Access Journals (Sweden)

Niina J. Ronkainen

2013-04-01

Full Text Available The evolution of 1st to 3rd generation electrochemical biosensors reflects a simplification and enhancement of the transduction pathway. However, in recent years, modification of the transducer with nanomaterials has become increasingly studied and imparts many advantages. The sensitivity and overall performance of enzymatic biosensors has improved tremendously as a result of incorporating nanomaterials in their fabrication. Given the unique and favorable qualities of gold nanoparticles, graphene and carbon nanotubes as applied to electrochemical biosensors, a consolidated survey of the different methods of nanomaterial immobilization on transducer surfaces and enzyme immobilization on these species is beneficial and timely. This review encompasses modification of enzymatic biosensors with gold nanoparticles, carbon nanotubes, and graphene.

Characterization of Carbon Onion Nanomaterials for Environmental Remediation

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The unique properties of carbonaceous nanomaterials, including small particle size, high surface area, and manipulatable surface chemistry, provide high potential for their application to environmental remediation. While research has devoted to develop nanotechnology for environm...

Magnetic and luminescent hybrid nanomaterial based on Fe{sub 3}O{sub 4} nanocrystals and GdPO{sub 4}:Eu{sup 3+} nanoneedles

Energy Technology Data Exchange (ETDEWEB)

Runowski, Marcin; Grzyb, Tomasz; Lis, Stefan, E-mail: blis@amu.edu.pl [Adam Mickiewicz University, Department of Rare Earths, Faculty of Chemistry (Poland)

2012-10-15

A bifunctional hybrid nanomaterial, which can show magnetic and luminescent properties, was obtained. A magnetic phase was synthesized as a core/shell type composite. Nanocrystalline magnetite, Fe{sub 3}O{sub 4} was used as the core and was encapsulated in a silica shell. The luminescent phase was GdPO{sub 4} doped with Eu{sup 3+} ions, as the emitter. The investigated materials were synthesized using a coprecipitation method. Encapsulated Fe{sub 3}O{sub 4} was 'trapped' in a nano-scaffold composed of GdPO{sub 4} crystalline nanoneedles. When an external magnetic field was applied, this hybrid composite was attracted in one direction. Also, the luminescent phase can move simultaneously with magnetite due to a 'trapping' effect. The structure and morphology of the obtained nanocomposites were examined with the use of transmission electron microscopy and X-ray powder diffraction. Spectroscopic properties of the Eu{sup 3+}-doped nanomaterials were studied by measuring their excitation and emission spectra as well as their luminescence decay times.Graphical Abstract.

Investigations into polymer and carbon nanomaterial separations

Science.gov (United States)

Owens, Cherie Nicole

utilize as novel UTLC substrates. Additionally, aligned electrospun UTLC (AE-UTLC) substrates were developed to compare to the randomly oriented electrospun (E-UTLC) devices. The PHB plates were compared to commercially available substrates for the separation of biological samples: nucleotides and steroids. The electrospun substrates show lower band broadening and higher reproducibility in a smaller development distance than commercially available TLC plates, conserving both resources and time. The AE-UTLC plates provided further enhancement of reproducibility and development time compared to E-UTLC plates. Thus, the P3HB E-UTLC phases are an excellent sustainable option for TLC as they are biodegradable and perform better than commercial phases. A third topic of interest is the study of ordered carbon nanomaterials. The typical amorphous carbon used as a stationary phase in Hypercarb ® is known to consist of basal- and edge-plane oriented sites. This heterogeneity of the stationary phase can lead to peak broadening that may be improved by using homogeneous carbon throughout. Amorphous, basal-plane, and edge-plane carbons were produced in-house through membrane template synthesis. Amorphous, basal-plane, and edge-plane carbons were then used separately as chromatographic phases in capillary electrochomatography (CEC). Differences in chromatographic performance between these species were assessed by modeling retention data for test solutes to determine Linear Solvation Energy Relationships (LSER). The LSER study for the three carbon phases indicates that the main difference is in the polarizability, and hydrogen bonding character of the surface leading to unique solute interactions. These results highlight the possible usefulness of using these phases independently.

Soft X-ray spectromicroscopy for speciation, quantitation and nano-eco-toxicology of nanomaterials.

Science.gov (United States)

Lawrence, J R; Swerhone, G D W; Dynes, J J; Korber, D R; Hitchcock, A P

2016-02-01

There is a critical need for methods that provide simultaneous detection, identification, quantitation and visualization of nanomaterials at their interface with biological and environmental systems. The approach should allow speciation as well as elemental analysis. Using the intrinsic X-ray absorption properties, soft X-ray scanning transmission X-ray spectromicroscopy (STXM) allows characterization and imaging of a broad range of nanomaterials, including metals, oxides and organic materials, and at the same time is able to provide detailed mapping of biological components. Thus, STXM offers considerable potential for application to research on nanomaterials in biology and the environment. The potential and limitations of STXM in this context are discussed using a range of examples, focusing on the interaction of nanomaterials with microbial cells, biofilms and extracellular polymers. The studies outlined include speciation and mapping of metal-containing nanomaterials (Ti, Ni, Cu) and carbon-based nanomaterials (multiwalled carbon nanotubes, C60 fullerene). The benefits of X-ray fluorescence detection in soft X-ray STXM are illustrated with a study of low levels of Ni in a natural river biofilm. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

Review on the Synthesis and Applications of Fe3O4 Nanomaterials

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Xiaodi Liu

2013-01-01

Full Text Available Recently, Fe3O4 nanomaterials have attracted tremendous attention because of their favorable electric and magnetic properties. Fe3O4 nanostructures with various morphologies have been successfully synthesized and have been used in many fields such as lithium-ion batteries (LIBs, wastewater treatment, and magnetic resonance imaging (MRI contrast agents. In this paper, we provide an in-depth discussion of recent development of Fe3O4 nanomaterials, including their effective synthetic methods and potential applications.

Predictive tests to evaluate oxidative potential of engineered nanomaterials

Science.gov (United States)

Ghiazza, Mara; Carella, Emanuele; Oliaro-Bosso, Simonetta; Corazzari, Ingrid; Viola, Franca; Fenoglio, Ivana

2013-04-01

Oxidative stress constitutes one of the principal injury mechanisms through which particulate toxicants (asbestos, crystalline silica, hard metals) and engineered nanomaterials can induce adverse health effects. ROS may be generated indirectly by activated cells and/or directly at the surface of the material. The occurrence of these processes depends upon the type of material. Many authors have recently demonstrated that metal oxides and carbon-based nanoparticles may influence (increasing or decreasing) the generation of oxygen radicals in a cell environment. Metal oxide, such as iron oxides, crystalline silica, and titanium dioxide are able to generate free radicals via different mechanisms causing an imbalance within oxidant species. The increase of ROS species may lead to inflammatory responses and in some cases to the development of cancer. On the other hand carbon-based nanomaterials, such as fullerene, carbon nanotubes, carbon black as well as cerium dioxide are able to scavenge the free radicals generated acting as antioxidant. The high numbers of new-engineered nanomaterials, which are introduced in the market, are exponentially increasing. Therefore the definition of toxicological strategies is urgently needed. The development of acellular screening tests will make possible the reduction of the number of in vitro and in vivo tests to be performed. An integrated protocol that may be used to predict the oxidant/antioxidant potential of engineered nanoparticles will be here presented.

Predictive tests to evaluate oxidative potential of engineered nanomaterials

International Nuclear Information System (INIS)

Ghiazza, Mara; Carella, Emanuele; Corazzari, Ingrid; Fenoglio, Ivana; Oliaro-Bosso, Simonetta; Viola, Franca

2013-01-01

Oxidative stress constitutes one of the principal injury mechanisms through which particulate toxicants (asbestos, crystalline silica, hard metals) and engineered nanomaterials can induce adverse health effects. ROS may be generated indirectly by activated cells and/or directly at the surface of the material. The occurrence of these processes depends upon the type of material. Many authors have recently demonstrated that metal oxides and carbon-based nanoparticles may influence (increasing or decreasing) the generation of oxygen radicals in a cell environment. Metal oxide, such as iron oxides, crystalline silica, and titanium dioxide are able to generate free radicals via different mechanisms causing an imbalance within oxidant species. The increase of ROS species may lead to inflammatory responses and in some cases to the development of cancer. On the other hand carbon-based nanomaterials, such as fullerene, carbon nanotubes, carbon black as well as cerium dioxide are able to scavenge the free radicals generated acting as antioxidant. The high numbers of new-engineered nanomaterials, which are introduced in the market, are exponentially increasing. Therefore the definition of toxicological strategies is urgently needed. The development of acellular screening tests will make possible the reduction of the number of in vitro and in vivo tests to be performed. An integrated protocol that may be used to predict the oxidant/antioxidant potential of engineered nanoparticles will be here presented.

Contributions and mechanisms of action of graphite nanomaterials in ultra high performance concrete

Science.gov (United States)

Sbia, Libya Ahmed

Ultra-high performance concrete (UHPC) reaches high strength and impermeability levels by using a relatively large volume fraction of a dense binder with fine microstructure in combination with high-quality aggregates of relatively small particle size, and reinforcing fibers. The dense microstructure of the cementitions binder is achieved by raising the packing density of the particulate matter, which covers sizes ranging from few hundred nanometers to few millimeters. The fine microstructure of binder in UHPC is realized by effective use of pozzolans to largely eliminate the coarse crystalline particles which exist among cement hydrates. UHPC incorporates (steel) fibers to overcome the brittleness of its dense, finely structured cementitious binder. The main thrust of this research is to evaluate the benefits of nanmaterials in UHPC. The dense, finely structure cementitious binder as well as the large volume fraction of the binder in UHPC benefit the dispersion of nanomaterials, and their interfacial interactions. The relatively close spacing of nanomaterials within the cementitious binder of UHPC enables them to render local reinforcement effects in critically stressed regions such as those in the vicinity of steel reinforcement and prestressing strands as well as fibers. Nanomaterials can also raise the density of the binder in UHPC by extending the particle size distribution down to the few nanometers range. Comprehensive experimental studies supported by theoretical investigations were undertake in order to optimize the use of nanomaterials in UHPC, identity the UHPC (mechanical) properties which benefit from the introduction of nanomaterials, and define the mechanisms of action of nanomaterials in UHPC. Carbon nanofiber was the primary nanomaterial used in this investigation. Some work was also conducted with graphite nanoplates. The key hypotheses of the project were as follows: (i) nanomaterials can make important contributions to the packing density of the

Safety assessment of nanomaterials using an advanced decision-making framework, the DF4nanoGrouping

Science.gov (United States)

Landsiedel, Robert; Ma-Hock, Lan; Wiench, Karin; Wohlleben, Wendel; Sauer, Ursula G.

2017-05-01

As presented at the 2016 TechConnect World Innovation Conference on 22-25 May 2016 in Washington DC, USA, the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) `Nano Task Force' proposes a Decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping) consisting of three tiers to assign nanomaterials to four main groups with possible further subgrouping to refine specific information needs. The DF4nanoGrouping covers all relevant aspects of a nanomaterial's life cycle and biological pathways: intrinsic material properties and system-dependent properties (that depend upon the nanomaterial's respective surroundings), biopersistence, uptake and biodistribution, and cellular and apical toxic effects. Use, release, and exposure route may be applied as `qualifiers' to determine if, e.g., nanomaterials cannot be released from products, which may justify waiving of testing. The four main groups encompass (1) soluble, (2) biopersistent high aspect ratio, (3) passive, and (4) active nanomaterials. The DF4nanoGrouping foresees a stepwise evaluation of nanomaterial properties and effects with increasing biological complexity. In case studies covering carbonaceous nanomaterials, metal oxide, and metal sulfate nanomaterials, amorphous silica and organic pigments (all nanomaterials having primary particle sizes below 100 nm), the usefulness of the DF4nanoGrouping for nanomaterial hazard assessment was confirmed. The DF4nanoGrouping facilitates grouping and targeted testing of nanomaterials. It ensures that sufficient data for the risk assessment of a nanomaterial are available, and it fosters the use of non-animal methods. No studies are performed that do not provide crucial data. Thereby, the DF4nanoGrouping serves to save both animals and resources.

Biomedical Platforms Based on Composite Nanomaterials and Cellular Toxicity

Science.gov (United States)

Bellucci, Stefano; Bergamaschi, A.; Bottini, M.; Magrini, A.; Mustelin, T.

2007-03-01

Carbon nanotubes possess unique chemical, physical, optical, and magnetic properties, which make them suitable for many uses in industrial products and in the field of nanotechnology, including nanomedicine. We describe fluorescent nanocomposites for use in biosensors or nanoelectronics. Then we describe recent results on the issue of cytotoxicity of carbon nanotubes obtained in our labs. Silica nanoparticles have been widely used for biosensing and catalytic applications due to their large surface area-to-volume ratio, straightforward manufacture, and the compatibility of silica chemistry with covalent coupling of biomolecules. Carbon nanotubes-composite materials, such as those based on Carbon nanotubes bound to nanoparticles, are suitable, in order to tailor Carbon nanotubes properties for specific applications. We present a tunable synthesis of Multi Wall Carbon nanotubes-Silica nanoparticles. The control of the nanotube morphology and the bead size, coupled with the versatility of silica chemistry, makes these structures an excellent platform for the development of biosensors (optical, magnetic and catalytic applications). We describe the construction and characterization of supramolecular nanostructures consisting of ruthenium-complex luminophores, directly grafted onto short oxidized single-walled carbon nanotubes or physically entrapped in silica nanobeads, which had been covalently linked to short oxidized single-walled carbon nanotubes or hydrophobically adsorbed onto full-length multi-walled carbon nanotubes. These structures have been evaluated as potential electron-acceptor complexes for use in the fabrication of photovoltaic devices, and for their properties as fluorescent nanocomposites for use in biosensors or nanoelectronics. Finally, we compare the toxicity of pristine and oxidized Multi Walled Carbon nanotubes on human T cells - which would be among the first exposed cell types upon intravenous administration of Carbon nanotubes in therapeutic

Microwave assisted scalable synthesis of titanium ferrite nanomaterials

Science.gov (United States)

Shukla, Abhishek; Bhardwaj, Abhishek K.; Singh, S. C.; Uttam, K. N.; Gautam, Nisha; Himanshu, A. K.; Shah, Jyoti; Kotnala, R. K.; Gopal, R.

2018-04-01

Titanium ferrite magnetic nanomaterials are synthesized by one-step, one pot, and scalable method assisted by microwave radiation. Effects of titanium content and microwave exposure time on size, shape, morphology, yield, bonding nature, crystalline structure, and magnetic properties of titanium ferrite nanomaterials are studied. As-synthesized nanomaterials are characterized by X-ray diffraction (XRD), ultraviolet-visible absorption spectroscopy (UV-Vis), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, transmission electron microscopy (TEM), and vibrating sample magnetometer measurements. XRD measurements depict the presence of two phases of titanium ferrite into the same sample, where crystallite size increases from ˜33 nm to 37 nm with the increase in titanium concentration. UV-Vis measurement showed broad spectrum in the spectral range of 250-600 nm which reveals that its characteristic peaks lie between ultraviolet and visible region; ATR-FTIR and Raman measurements predict iron-titanium oxide structures that are consistent with XRD results. The micrographs of TEM and selected area electron diffraction patterns show formation of hexagonal shaped particles with a high degree of crystallinity and presence of multi-phase. Energy dispersive spectroscopy measurements confirm that Ti:Fe compositional mass ratio can be controlled by tuning synthesis conditions. Increase of Ti defects into titanium ferrite lattice, either by increasing titanium precursor or by increasing exposure time, enhances its magnetic properties.

Biomimetic three-dimensional nanocrystalline hydroxyapatite and magnetically synthesized single-walled carbon nanotube chitosan nanocomposite for bone regeneration

Directory of Open Access Journals (Sweden)

Im O

2012-04-01

Full Text Available Owen Im1, Jian Li2, Mian Wang2, Lijie Grace Zhang2,3, Michael Keidar2,31Department of Biomedical Engineering, Duke University, Durham, NC; 2Department of Mechanical and Aerospace Engineering, 3Institute for Biomedical Engineering and Institute for Nanotechnology, The George Washington University, Washington, DC, USABackground: Many shortcomings exist in the traditional methods of treating bone defects, such as donor tissue shortages for autografts and disease transmission for allografts. The objective of this study was to design a novel three-dimensional nanostructured bone substitute based on magnetically synthesized single-walled carbon nanotubes (SWCNT, biomimetic hydrothermally treated nanocrystalline hydroxyapatite, and a biocompatible hydrogel (chitosan. Both nanocrystalline hydroxyapatite and SWCNT have a biomimetic nanostructure, excellent osteoconductivity, and high potential to improve the load-bearing capacity of hydrogels.Methods: Specifically, three-dimensional porous chitosan scaffolds with different concentrations of nanocrystalline hydroxyapatite and SWCNT were created to support the growth of human osteoblasts (bone-forming cells using a lyophilization procedure. Two types of SWCNT were synthesized in an arc discharge with a magnetic field (B-SWCNT and without a magnetic field (N-SWCNT for improving bone regeneration.Results: Nanocomposites containing magnetically synthesized B-SWCNT had superior cytocompatibility properties when compared with nonmagnetically synthesized N-SWCNT. B-SWCNT have much smaller diameters and are twice as long as their nonmagnetically prepared counterparts, indicating that the dimensions of carbon nanotubes can have a substantial effect on osteoblast attachment.Conclusion: This study demonstrated that a chitosan nanocomposite with both B-SWCNT and 20% nanocrystalline hydroxyapatite could achieve a higher osteoblast density when compared with the other experimental groups, thus making this nanocomposite

REACH and nanomaterials: current status

International Nuclear Information System (INIS)

Alessandrelli, Maria; Di Prospero Fanghella, Paola; Polci, Maria Letizia; Castelli, Stefano; Pettirossi, Flavio

2015-01-01

New challenges for regulators are emerging about a specific assessment and appropriate management of the potential risks of nanomaterials. In the framework of European legislation on chemicals, Regulation (EC) No. 1907/2006 REACH aims to ensure the safety of human health and the environment through the collection of information on the physico-chemical characteristics of the substances and on their profile (eco) toxicological and the identification of appropriate risk management linked to 'exposure to these substances without impeding scientific progress and the competitiveness of industry. In order to cover the current shortage of information on the safety of nanomaterials and tackle the acknowledged legal vacuum, are being a rich activities, carried out both by regulators both by stake holders, and discussions on the proposals for adapting the European regulatory framework for chemicals . The European Commission is geared to strengthen the REACH Regulation by means of updates of its annexes. The importance of responding to the regulatory requirements has highlighted the need for cooperation between European organizations, scientists and industries to promote and ensure the safe use of nanomaterials. [it

Low-Dimensional Nanomaterials as Active Layer Components in Thin-Film Photovoltaics

Science.gov (United States)

Shastry, Tejas Attreya

Thin-film photovoltaics offer the promise of cost-effective and scalable solar energy conversion, particularly for applications of semi-transparent solar cells where the poor absorption of commercially-available silicon is inadequate. Applications ranging from roof coatings that capture solar energy to semi-transparent windows that harvest the immense amount of incident sunlight on buildings could be realized with efficient and stable thin-film solar cells. However, the lifetime and efficiency of thin-film solar cells continue to trail their inorganic silicon counterparts. Low-dimensional nanomaterials, such as carbon nanotubes and two-dimensional metal dichalcogenides, have recently been explored as materials in thin-film solar cells due to their exceptional optoelectronic properties, solution-processability, and chemical inertness. Thus far, issues with the processing of these materials has held back their implementation in efficient photovoltaics. This dissertation reports processing advances that enable demonstrations of low-dimensional nanomaterials in thin-film solar cells. These low-dimensional photovoltaics show enhanced photovoltaic efficiency and environmental stability in comparison to previous devices, with a focus on semiconducting single-walled carbon nanotubes as an active layer component. The introduction summarizes recent advances in the processing of carbon nanotubes and their implementation through the thin-film photovoltaic architecture, as well as the use of two-dimensional metal dichalcogenides in photovoltaic applications and potential future directions for all-nanomaterial solar cells. The following chapter reports a study of the interaction between carbon nanotubes and surfactants that enables them to be sorted by electronic type via density gradient ultracentrifugation. These insights are utilized to construct of a broad distribution of carbon nanotubes that absorb throughout the solar spectrum. This polychiral distribution is then shown

Application of nanomaterials in the bioanalytical detection of disease-related genes.

Science.gov (United States)

Zhu, Xiaoqian; Li, Jiao; He, Hanping; Huang, Min; Zhang, Xiuhua; Wang, Shengfu

2015-12-15

In the diagnosis of genetic diseases and disorders, nanomaterials-based gene detection systems have significant advantages over conventional diagnostic systems in terms of simplicity, sensitivity, specificity, and portability. In this review, we describe the application of nanomaterials for disease-related genes detection in different methods excluding PCR-related method, such as colorimetry, fluorescence-based methods, electrochemistry, microarray methods, surface-enhanced Raman spectroscopy (SERS), quartz crystal microbalance (QCM) methods, and dynamic light scattering (DLS). The most commonly used nanomaterials are gold, silver, carbon and semiconducting nanoparticles. Various nanomaterials-based gene detection methods are introduced, their respective advantages are discussed, and selected examples are provided to illustrate the properties of these nanomaterials and their emerging applications for the detection of specific nucleic acid sequences. Copyright © 2015. Published by Elsevier B.V.

Enhanced specific heat capacity of molten salt-based nanomaterials: Effects of nanoparticle dispersion and solvent material

International Nuclear Information System (INIS)

Jo, Byeongnam; Banerjee, Debjyoti

2014-01-01

This study investigated the effect of nanoparticle dispersion on the specific heat capacity for carbonate salt mixtures doped with graphite nanoparticles. The effect of the solvent material was also examined. Binary carbonate salt mixtures consisting of lithium carbonate and potassium carbonate were used as the base material for the graphite nanomaterial. The different dispersion uniformity of the nanoparticles was created by employing two distinct synthesis protocols for the nanomaterial. Different scanning calorimetry was employed to measure the specific heat capacity in both solid and liquid phases. The results showed that doping the molten salt mixture with the graphite nanoparticles significantly raised the specific heat capacity, even in minute concentrations of graphite nanoparticles. Moreover, greater enhancement in the specific heat capacity was observed from the nanomaterial samples with more homogeneous dispersion of the nanoparticles. A molecular dynamics simulation was also performed for the nanomaterials used in the specific heat capacity measurements to explain the possible mechanisms for the enhanced specific heat capacity, including the compressed layering and the species concentration of liquid solvent molecules

Thermal Resistance across Interfaces Comprising Dimensionally Mismatched Carbon Nanotube-Graphene Junctions in 3D Carbon Nanomaterials

Directory of Open Access Journals (Sweden)

Jungkyu Park

2014-01-01

Full Text Available In the present study, reverse nonequilibrium molecular dynamics is employed to study thermal resistance across interfaces comprising dimensionally mismatched junctions of single layer graphene floors with (6,6 single-walled carbon nanotube (SWCNT pillars in 3D carbon nanomaterials. Results obtained from unit cell analysis indicate the presence of notable interfacial thermal resistance in the out-of-plane direction (along the longitudinal axis of the SWCNTs but negligible resistance in the in-plane direction along the graphene floor. The interfacial thermal resistance in the out-of-plane direction is understood to be due to the change in dimensionality as well as phonon spectra mismatch as the phonons propagate from SWCNTs to the graphene sheet and then back again to the SWCNTs. The thermal conductivity of the unit cells was observed to increase nearly linearly with an increase in cell size, that is, pillar height as well as interpillar distance, and approaches a plateau as the pillar height and the interpillar distance approach the critical lengths for ballistic thermal transport in SWCNT and single layer graphene. The results indicate that the thermal transport characteristics of these SWCNT-graphene hybrid structures can be tuned by controlling the SWCNT-graphene junction characteristics as well as the unit cell dimensions.

Electrode nanomaterials for lithium-ion batteries

International Nuclear Information System (INIS)

Yaroslavtsev, A B; Kulova, T L; Skundin, A M

2015-01-01

The state-of-the-art in the field of cathode and anode nanomaterials for lithium-ion batteries is considered. The use of these nanomaterials provides higher charge and discharge rates, reduces the adverse effect of degradation processes caused by volume variations in electrode materials upon lithium intercalation and deintercalation and enhances the power and working capacity of lithium-ion batteries. In discussing the cathode materials, attention is focused on double phosphates and silicates of lithium and transition metals and also on vanadium oxides. The anode materials based on nanodispersions of carbon, silicon, certain metals, oxides and on nanocomposites are also described. The bibliography includes 714 references

Surface engineering of graphene-based nanomaterials for biomedical applications.

Science.gov (United States)

Shi, Sixiang; Chen, Feng; Ehlerding, Emily B; Cai, Weibo

2014-09-17

Graphene-based nanomaterials have attracted tremendous interest over the past decade due to their unique electronic, optical, mechanical, and chemical properties. However, the biomedical applications of these intriguing nanomaterials are still limited due to their suboptimal solubility/biocompatibility, potential toxicity, and difficulties in achieving active tumor targeting, just to name a few. In this Topical Review, we will discuss in detail the important role of surface engineering (i.e., bioconjugation) in improving the in vitro/in vivo stability and enriching the functionality of graphene-based nanomaterials, which can enable single/multimodality imaging (e.g., optical imaging, positron emission tomography, magnetic resonance imaging) and therapy (e.g., photothermal therapy, photodynamic therapy, and drug/gene delivery) of cancer. Current challenges and future research directions are also discussed and we believe that graphene-based nanomaterials are attractive nanoplatforms for a broad array of future biomedical applications.

Synthesis of nanoparticles and nanomaterials biological approaches

CERN Document Server

Abdullaeva, Zhypargul

2017-01-01

This book covers biological synthesis approaches for nanomaterials and nanoparticles, including introductory material on their structure, phase compositions and morphology, nanomaterials chemical, physical, and biological properties. The chapters of this book describe in sequence the synthesis of various nanoparticles by microorganisms, bacteria, yeast, algae, and actynomycetes; plant and plant extract-based synthesis; and green synthesis methods. Each chapter provides basic knowledge on the synthesis of nanomaterials, defines fundamental terms, and aims to build a solid foundation of knowledge, followed by explanations, examples, visual photographs, schemes, tables and illustrations. Each chapter also contains control questions, problem drills, as well as case studies that clarify theory and the explanations given in the text. This book is ideal for researchers and advanced graduate students in materials engineering, biotechnology, and nanotechnology fields. As a reference book this work is also appropriate ...

Occupational exposure limits for nanomaterials: state of the art

International Nuclear Information System (INIS)

Schulte, P. A.; Murashov, V.; Zumwalde, R.; Kuempel, E. D.; Geraci, C. L.

2010-01-01

Assessing the need for and effectiveness of controlling airborne exposures to engineered nanomaterials in the workplace is difficult in the absence of occupational exposure limits (OELs). At present, there are practically no OELs specific to nanomaterials that have been adopted or promulgated by authoritative standards and guidance organizations. The vast heterogeneity of nanomaterials limits the number of specific OELs that are likely to be developed in the near future, but OELs could be developed more expeditiously for nanomaterials by applying dose-response data generated from animal studies for specific nanoparticles across categories of nanomaterials with similar properties and modes of action. This article reviews the history, context, and approaches for developing OELs for particles in general and nanoparticles in particular. Examples of approaches for developing OELs for titanium dioxide and carbon nanotubes are presented and interim OELs from various organizations for some nanomaterials are discussed. When adequate dose-response data are available in animals or humans, quantitative risk assessment methods can provide estimates of adverse health risk of nanomaterials in workers and, in conjunction with workplace exposure and control data, provide a basis for determining appropriate exposure limits. In the absence of adequate quantitative data, qualitative approaches to hazard assessment, exposure control, and safe work practices are prudent measures to reduce hazards in workers.

Granular biodurable nanomaterials: No convincing evidence for systemic toxicity.

Science.gov (United States)

Moreno-Horn, Marcus; Gebel, Thomas

2014-11-01

Nanomaterials are usually defined by primary particle diameters ranging from 1 to 100 nm. The scope of this review is an evaluation of experimental animal studies dealing with the systemic levels and putative systemic effects induced by nanoparticles which can be characterized as being granular biodurable particles without known specific toxicity (GBP). Relevant examples of such materials comprise nanosized titanium dioxide (TiO2) and carbon black. The question was raised whether GBP nanomaterials systemically accumulate and may possess a relevant systemic toxicity. With few exceptions, the 56 publications reviewed were not performed using established standard protocols, for example, OECD guidelines but used non-standard study designs. The studies including kinetic investigations indicated that GBP nanomaterials were absorbed and systemically distributed to rather low portions only. There was no valid indication that GPB nanomaterials possess novel toxicological hazard properties. In addition, no convincing evidence for a relevant specific systemic toxicity of GBP nanomaterials could be identified. The minority of the papers reviewed (15/56) investigated both nanosized and microsized GBP materials in parallel. A relevant different translocation of GBP nanomaterials in contrast to GBP micromaterials was not observed in these studies. There was no evidence that GPB nanomaterials possess toxicological properties other than their micromaterial counterparts.

Occupational exposure limits for nanomaterials: state of the art

Science.gov (United States)

Schulte, P. A.; Murashov, V.; Zumwalde, R.; Kuempel, E. D.; Geraci, C. L.

2010-08-01

Assessing the need for and effectiveness of controlling airborne exposures to engineered nanomaterials in the workplace is difficult in the absence of occupational exposure limits (OELs). At present, there are practically no OELs specific to nanomaterials that have been adopted or promulgated by authoritative standards and guidance organizations. The vast heterogeneity of nanomaterials limits the number of specific OELs that are likely to be developed in the near future, but OELs could be developed more expeditiously for nanomaterials by applying dose-response data generated from animal studies for specific nanoparticles across categories of nanomaterials with similar properties and modes of action. This article reviews the history, context, and approaches for developing OELs for particles in general and nanoparticles in particular. Examples of approaches for developing OELs for titanium dioxide and carbon nanotubes are presented and interim OELs from various organizations for some nanomaterials are discussed. When adequate dose-response data are available in animals or humans, quantitative risk assessment methods can provide estimates of adverse health risk of nanomaterials in workers and, in conjunction with workplace exposure and control data, provide a basis for determining appropriate exposure limits. In the absence of adequate quantitative data, qualitative approaches to hazard assessment, exposure control, and safe work practices are prudent measures to reduce hazards in workers.

Synthesis, surface modification/decoration of luminescent–magnetic core/shell nanomaterials, based on the lanthanide doped fluorides (Fe{sub 3}O{sub 4}/SiO{sub 2}/NH{sub 2}/PAA/LnF{sub 3})

Energy Technology Data Exchange (ETDEWEB)

Runowski, Marcin; Lis, Stefan, E-mail: blis@amu.edu.pl

2016-02-15

The synthesized magnetite nanoparticles (10–15 nm) were successfully coated with amine modified silica nanoshell, which led to the formation of core/shell type nanostructures (30–50 nm). The as-prepared nanoparticles were surface modified with polyacrylic acid (PAA) via electrostatic interactions of –NH{sub 2} and –COOH groups. Afterwards, the surface PAA molecules acted as complexing agents of the introduced lanthanide (Ln{sup 3+}) ions. Subsequently, the as-prepared nanostructures were surface decorated with luminescent LnF{sub 3} nanoparticles, forming Eu{sup 3+} or Tb{sup 3+} doped Fe{sub 3}O{sub 4}/SiO{sub 2}/NH{sub 2}/PAA/LnF{sub 3} nanomaterials (50–100 nm). The obtained luminescent–magnetic products exhibited simultaneously bright red or green emission under UV lamp irradiation (λ{sub ex}=254 nm), and a response for the applied magnetic field (strong magnet attracts the colloidal particles, dispersed in aqueous medium). After the synthesis, properties of the nanomaterials were investigated by powder X-ray diffraction (XRD) technique, transmission electron microscopy (TEM), infrared spectroscopy (IR) and spectrofluorometry (analysis of excitation/emission spectra and luminescence decay curves). Such advanced nanomaterials can be potentially used in multimodal imaging, targeted therapies and as multifunctional contrast agents, novel luminescent–magnetic tracers, protection of documents, etc. - Highlights: • Luminescent–magnetic nanomaterials Fe{sub 3}O{sub 4}/SiO{sub 2}/NH{sub 2}/PAA/LnF{sub 3} were synthesized. • Core/shell nanostructures were obtained by surface modification of nanoparticles. • Luminescent lanthanide fluoride nanoparticles doped with Eu{sup 3+} and Tb{sup 3+} ions. • Multifunctional core/shell nanostructures exhibited red or green emission. • Nanomaterials formed stable aqueous colloids.

Black carbon and mineral dust in snow cover on the Tibetan Plateau

Science.gov (United States)

Zhang, Yulan; Kang, Shichang; Sprenger, Michael; Cong, Zhiyuan; Gao, Tanguang; Li, Chaoliu; Tao, Shu; Li, Xiaofei; Zhong, Xinyue; Xu, Min; Meng, Wenjun; Neupane, Bigyan; Qin, Xiang; Sillanpää, Mika

2018-02-01

Snow cover plays a key role for sustaining ecology and society in mountainous regions. Light-absorbing particulates (including black carbon, organic carbon, and mineral dust) deposited on snow can reduce surface albedo and contribute to the near-worldwide melting of snow and ice. This study focused on understanding the role of black carbon and other water-insoluble light-absorbing particulates in the snow cover of the Tibetan Plateau (TP). The results found that the black carbon, organic carbon, and dust concentrations in snow cover generally ranged from 202 to 17 468 ng g-1, 491 to 13 880 ng g-1, and 22 to 846 µg g-1, respectively, with higher concentrations in the central to northern areas of the TP. Back trajectory analysis suggested that the northern TP was influenced mainly by air masses from Central Asia with some Eurasian influence, and air masses in the central and Himalayan region originated mainly from Central and South Asia. The relative biomass-burning-sourced black carbon contributions decreased from ˜ 50 % in the southern TP to ˜ 30 % in the northern TP. The relative contribution of black carbon and dust to snow albedo reduction reached approximately 37 and 15 %, respectively. The effect of black carbon and dust reduced the snow cover duration by 3.1 ± 0.1 to 4.4 ± 0.2 days. Meanwhile, the black carbon and dust had important implications for snowmelt water loss over the TP. The findings indicate that the impacts of black carbon and mineral dust need to be properly accounted for in future regional climate projections, particularly in the high-altitude cryosphere.

Balanced improvement of high performance concrete material properties with modified graphite nanomaterials

Science.gov (United States)

Peyvandi, Amirpasha

Graphite nanomaterials offer distinct features for effective reinforcement of cementitious matrices in the pre-crack and post-crack ranges of behavior. Thoroughly dispersed and well-bonded nanomaterials provide for effective control of the size and propagation of defects (microcracks) in matrix, and also act as closely spaced barriers against diffusion of moisture and aggressive solutions into concrete. Modified graphite nanomaterials can play multi-faceted roles towards enhancing the mechanical, physical and functional attributes of concrete materials. Graphite nanoplatelets (GP) and carbon nanofibers (CNF) were chosen for use in cementitious materials. Experimental results highlighted the balanced gains in diverse engineering properties of high-performance concrete realized by introduction of graphite nanomaterials. Nuclear Magnetic Resonance (NMR) spectroscopy was used in order to gain further insight into the effects of nanomaterials on the hydration process and structure of cement hydrates. NMR exploits the magnetic properties of certain atomic nuclei, and the sensitivity of these properties to local environments to generate data which enables determination of the internal structure, reaction state, and chemical environment of molecules and bulk materials. 27 Al and 29Si NMR spectroscopy techniques were employed in order to evaluate the effects of graphite nanoplatelets on the structure of cement hydrates, and their resistance to alkali-silica reaction (ASR), chloride ion diffusion, and sulfate attack. Results of 29Si NMR spectroscopy indicated that the percent condensation of C-S-H in cementitious paste was lowered in the presence of nanoplatelets at the same age. The extent of chloride diffusion was assessed indirectly by detecting Friedel's salt as a reaction product of chloride ions with aluminum-bearing cement hydrates. Graphite nanoplatelets were found to significantly reduce the concentration of Friedel's salt at different depths after various periods

Nanomaterials application in electrochemical detection of heavy metals

International Nuclear Information System (INIS)

Aragay, Gemma; Merkoçi, Arben

2012-01-01

Highlights: ► We review the recent trends in the application of nanomaterials for electrochemical detection of heavy metals. ► Different types of nanomaterials including metal nanoparticles, different carbon nanomaterials or nanochannels have been applied on the electrochemical analysis of heavy metals in various sensing formats/configurations. ► The great properties of nanomaterials allow the new devices to show advantages in terms of sensing performance (i.e. increase the sensitivity, decrease the detection limits and improve the stability). ► Between the various electrochemical techniques, voltammetric and potentiometric based ones are particularly taking interesting advantages by the incorporation of new nanomaterials due to the improved electrocatalytic properties beside the increase of the sensor's transducing area. - Abstract: Recent trends in the application of nanomaterials for electrochemical detection of heavy metals are shown. Various nanomaterials such as nanoparticles, nanowires, nanotubes, nanochannels, graphene, etc. have been explored either as modifiers of electrodes or as new electrode materials with interest to be applied in electrochemical stripping analysis, ion-selective detection, field-effect transistors or other indirect heavy metals (bio)detection alternatives. The developed devices have shown increased sensitivity and decreased detection limits between other improvements of analytical performance data. The phenomena behind nanomaterials responses are also discussed and some typical responses data of the developed systems either in standard solutions or in real samples are given. The developed nanomaterials based electrochemical systems are giving new inputs to the existing devices or leading to the development of novel heavy metal detection tools with interest for applications in field such as diagnostics, environmental and safety and security controls or other industries.

Characterization of nanomaterials with transmission electron microscopy

KAUST Repository

Anjum, Dalaver H.

2016-08-01

The field of nanotechnology is about research and development on materials whose at least one dimension is in the range of 1 to 100 nanometers. In recent years, the research activity for developing nano-materials has grown exponentially owing to the fact that they offer better solutions to the challenges faced by various fields such as energy, food, and environment. In this paper, the importance of transmission electron microscopy (TEM) based techniques is demonstrated for investigating the properties of nano-materials. Specifically the nano-materials that are investigated in this report include gold nano-particles (Au-NPs), silver atom-clusters (Ag-ACs), tantalum single-atoms (Ta-SAs), carbon materials functionalized with iron cobalt (Fe-Co) NPs and titania (TiO2) NPs, and platinum loaded Ceria (Pt-CeO2) Nano composite. TEM techniques that are employed to investigate nano-materials include aberration corrected bright-field TEM (BF-TEM), high-angle dark-field scanning TEM (HAADF-STEM), electron energy-loss spectroscopy (EELS), and BF-TEM electron tomography (ET). With the help presented of results in this report, it is proved herein that as many TEM techniques as available in a given instrument are essential for a comprehensive nano-scale analysis of nanomaterials.

Toxicity and efficacy of carbon nanotubes and graphene: the utility of carbon-based nanoparticles in nanomedicine.

Science.gov (United States)

Zhang, Yongbin; Petibone, Dayton; Xu, Yang; Mahmood, Meena; Karmakar, Alokita; Casciano, Dan; Ali, Syed; Biris, Alexandru S

2014-05-01

Carbon-based nanomaterials have attracted great interest in biomedical applications such as advanced imaging, tissue regeneration, and drug or gene delivery. The toxicity of the carbon nanotubes and graphene remains a debated issue although many toxicological studies have been reported in the scientific community. In this review, we summarize the biological effects of carbon nanotubes and graphene in terms of in vitro and in vivo toxicity, genotoxicity and toxicokinetics. The dose, shape, surface chemistry, exposure route and purity play important roles in the metabolism of carbon-based nanomaterials resulting in differential toxicity. Careful examination of the physico-chemical properties of carbon-based nanomaterials is considered a basic approach to correlate the toxicological response with the unique properties of the carbon nanomaterials. The reactive oxygen species-mediated toxic mechanism of carbon nanotubes has been extensively discussed and strategies, such as surface modification, have been proposed to reduce the toxicity of these materials. Carbon-based nanomaterials used in photothermal therapy, drug delivery and tissue regeneration are also discussed in this review. The toxicokinetics, toxicity and efficacy of carbon-based nanotubes and graphene still need to be investigated further to pave a way for biomedical applications and a better understanding of their potential applications to humans.

A Review of Carbon Nanomaterials’ Synthesis via the Chemical Vapor Deposition (CVD) Method

Science.gov (United States)

Manawi, Yehia M.; Samara, Ayman; Al-Ansari, Tareq; Atieh, Muataz A.

2018-01-01

Carbon nanomaterials have been extensively used in many applications owing to their unique thermal, electrical and mechanical properties. One of the prime challenges is the production of these nanomaterials on a large scale. This review paper summarizes the synthesis of various carbon nanomaterials via the chemical vapor deposition (CVD) method. These carbon nanomaterials include fullerenes, carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene, carbide-derived carbon (CDC), carbon nano-onion (CNO) and MXenes. Furthermore, current challenges in the synthesis and application of these nanomaterials are highlighted with suggested areas for future research. PMID:29772760

A Review of Carbon Nanomaterials’ Synthesis via the Chemical Vapor Deposition (CVD Method

Directory of Open Access Journals (Sweden)

Yehia M. Manawi

2018-05-01

Full Text Available Carbon nanomaterials have been extensively used in many applications owing to their unique thermal, electrical and mechanical properties. One of the prime challenges is the production of these nanomaterials on a large scale. This review paper summarizes the synthesis of various carbon nanomaterials via the chemical vapor deposition (CVD method. These carbon nanomaterials include fullerenes, carbon nanotubes (CNTs, carbon nanofibers (CNFs, graphene, carbide-derived carbon (CDC, carbon nano-onion (CNO and MXenes. Furthermore, current challenges in the synthesis and application of these nanomaterials are highlighted with suggested areas for future research.

On MHD nonlinear stretching flow of Powell–Eyring nanomaterial

Directory of Open Access Journals (Sweden)

Tasawar Hayat

Full Text Available This communication addresses the magnetohydrodynamic (MHD flow of Powell–Eyring nanomaterial bounded by a nonlinear stretching sheet. Novel features regarding thermophoresis and Brownian motion are taken into consideration. Powell–Eyring fluid is electrically conducted subject to non-uniform applied magnetic field. Assumptions of small magnetic Reynolds number and boundary layer approximation are employed in the mathematical development. Zero nanoparticles mass flux condition at the sheet is selected. Adequate transformation yield nonlinear ordinary differential systems. The developed nonlinear systems have been computed through the homotopic approach. Effects of different pertinent parameters on velocity, temperature and concentration fields are studied and analyzed. Further numerical data of skin friction and heat transfer rate is also tabulated and interpreted. Keywords: Powell–Eyring fluid, Magnetohydrodynamics, Nanomaterial, Nonlinear stretching surface

Optical response from functionalized atomically thin nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Malic, Ermin; Berghaeuser, Gunnar; Feierabend, Maja [Department of Physics, Chalmers University of Technology, Gothenburg (Sweden); Knorr, Andreas [Institut fuer Theoretische Physik, Technische Universitaet Berlin (Germany)

2017-10-15

Chemical functionalization of atomically thin nanostructures presents a promising strategy to create new hybrid nanomaterials with remarkable and externally controllable properties. Here, we review our research in the field of theoretical modeling of carbon nanotubes, graphene, and transition metal dichalcogenides located in molecular dipole fields. In particular, we provide a microscopic view on the change of the optical response of these technologically promising nanomaterials due to the presence of photo-active spiropyran molecules. The feature article presents a review of recent theoretical work providing microscopic view on the optical response of chemically functionalized carbon nanotubes, graphene, and monolayered transition metal dichalcogenides. In particular, we propose a novel sensor mechanism based on the molecule-induced activation of dark excitons. This results in a pronounced additional peak presenting an unambiguous optical fingerprint for the attached molecules. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Cooperative nanomaterials systems for cancer diagnosis and therapeutics

Science.gov (United States)

Park, Ji Ho

The unique electromagnetic and biologic properties of nanomaterials are being harnessed to build powerful new medical technologies. Particularly, there have been recently increasing interests in cancer nanotechnology, wherein nanomaterials play an important role in ultrasensitive imaging, targeting, and therapy of cancer. However, these nanomaterials typically function as individual units and are designed to independently perform their tasks. In this dissertation, new cooperative nanosystems consisting of two distinct nanomaterials that work together to target, identify, or treat tumors in vivo were studied. In the first two chapters, the synthesis of worm-shaped dextran-coated iron oxide nanoparticles (nanoworms, NW) exhibiting substantial in vivo circulation times and significant tumor targeting when coated with tumor-homing peptides were studied. NWs are also found to display a greater magnetic resonance (MR) response than the spherical nanoparticles. Next, two types of multifunctional nanoparticles were fabricated for simultaneous detection and treatment of cancer. Micellar hybrid nanoparticles (MHN) that contain magnetic nanoparticles, quantum dots, and an anti-cancer drug doxorubicin (DOX) within a single PEG-modified phospholipid micelle were first prepared. Simultaneous multimodal imaging (MR and fluorescence) and targeted drug delivery in vitro and in vivo was performed using DOX-incorporated targeted MHN. Secondly, luminescent porous silicon nanoparticles (LPSINP) that were drug-loadable, biodegradable and relatively non-toxic were prepared. In contrast to most inorganic nanomaterials, LPSINP were degraded in vivo in a relatively short time with no noticeable toxicity. The clearance and degradation of intravenously injected LPSINP in the bladder, liver, and spleen were established by whole-body fluorescence imaging. Finally, two types of cooperative nanomaterials systems to amplify targeting and deliver drugs efficiently to regions of tumor invasion were

Purifying Nanomaterials

Science.gov (United States)

Hung, Ching-Cheh (Inventor); Hurst, Janet (Inventor)

2014-01-01

A method of purifying a nanomaterial and the resultant purified nanomaterial in which a salt, such as ferric chloride, at or near its liquid phase temperature, is used to penetrate and wet the internal surfaces of a nanomaterial to dissolve impurities that may be present, for example, from processes used in the manufacture of the nanomaterial.

Global Tree Cover and Biomass Carbon on Agricultural Land: The contribution of agroforestry to global and national carbon budgets.

Science.gov (United States)

Zomer, Robert J; Neufeldt, Henry; Xu, Jianchu; Ahrends, Antje; Bossio, Deborah; Trabucco, Antonio; van Noordwijk, Meine; Wang, Mingcheng

2016-07-20

Agroforestry systems and tree cover on agricultural land make an important contribution to climate change mitigation, but are not systematically accounted for in either global carbon budgets or national carbon accounting. This paper assesses the role of trees on agricultural land and their significance for carbon sequestration at a global level, along with recent change trends. Remote sensing data show that in 2010, 43% of all agricultural land globally had at least 10% tree cover and that this has increased by 2% over the previous ten years. Combining geographically and bioclimatically stratified Intergovernmental Panel on Climate Change (IPCC) Tier 1 default estimates of carbon storage with this tree cover analysis, we estimated 45.3 PgC on agricultural land globally, with trees contributing >75%. Between 2000 and 2010 tree cover increased by 3.7%, resulting in an increase of >2 PgC (or 4.6%) of biomass carbon. On average, globally, biomass carbon increased from 20.4 to 21.4 tC ha(-1). Regional and country-level variation in stocks and trends were mapped and tabulated globally, and for all countries. Brazil, Indonesia, China and India had the largest increases in biomass carbon stored on agricultural land, while Argentina, Myanmar, and Sierra Leone had the largest decreases.

Comparative Study of the Electrochemical, Biomedical, and Thermal Properties of Natural and Synthetic Nanomaterials

Science.gov (United States)

Ghaemi, Ferial; Abdullah, Luqman Chuah; Kargarzadeh, Hanieh; Abdi, Mahnaz M.; Azli, Nur Farhana Waheeda Mohd; Abbasian, Maryam

2018-04-01

In this research, natural nanomaterials including cellulose nanocrystal (CNC), nanofiber cellulose (NFC), and synthetic nanoparticles such as carbon nanofiber (CNF) and carbon nanotube (CNT) with different structures, sizes, and surface areas were produced and analyzed. The most significant contribution of this study is to evaluate and compare these nanomaterials based on the effects of their structures and morphologies on their electrochemical, biomedical, and thermal properties. Based on the obtained results, the natural nanomaterials with low dimension and surface area have zero cytotoxicity effects on the living cells at 12.5 and 3.125 μg/ml concentrations of NFC and CNC, respectively. Meanwhile, synthetic nanomaterials with the high surface area around 15.3-21.1 m2/g and significant thermal stability (480 °C-600 °C) enhance the output of electrode by creating a higher surface area and decreasing the current flow resistance.

Net Community Metabolism and Seawater Carbonate Chemistry Scale Non-intuitively with Coral Cover

Directory of Open Access Journals (Sweden)

Heather N. Page

2017-05-01

Full Text Available Coral cover and reef health have been declining globally as reefs face local and global stressors including higher temperature and ocean acidification (OA. Ocean warming and acidification will alter rates of benthic reef metabolism (i.e., primary production, respiration, calcification, and CaCO3 dissolution, but our understanding of community and ecosystem level responses is limited in terms of functional, spatial, and temporal scales. Furthermore, dramatic changes in coral cover and benthic metabolism could alter seawater carbonate chemistry on coral reefs, locally alleviating or exacerbating OA. This study examines how benthic metabolic rates scale with changing coral cover (0–100%, and the subsequent influence of these coral communities on seawater carbonate chemistry based on mesocosm experiments in Bermuda and Hawaii. In Bermuda, no significant differences in benthic metabolism or seawater carbonate chemistry were observed for low (40% and high (80% coral cover due to large variability within treatments. In contrast, significant differences were detected between treatments in Hawaii with benthic metabolic rates increasing with increasing coral cover. Observed increases in daily net community calcification and nighttime net respiration scaled proportionally with coral cover. This was not true for daytime net community organic carbon production rates, which increased the most between 0 and 20% coral cover and then less so between 20 and 100%. Consequently, diel variability in seawater carbonate chemistry increased with increasing coral cover, but absolute values of pH, Ωa, and pCO2 were not significantly different during daytime. To place the results of the mesocosm experiments into a broader context, in situ seawater carbon dioxide (CO2 at three reef sites in Bermuda and Hawaii were also evaluated; reefs with higher coral cover experienced a greater range of diel CO2 levels, complementing the mesocosm results. The results from this study

Magnetic Cluster States in Nanostructured Materials

International Nuclear Information System (INIS)

Leslie-Pelecky, Diandra

2008-01-01

The goal of this work is to fabricate model nanomaterials with different types of disorder and use atomic-scale characterization and macroscopic magnetization measurements to understand better how specific types of disorder affects macroscopic magnetic behavior. This information can be used to produce magnetic nanomaterials with specific properties for applications such as permanent magnets, soft magnetic material for motors and biomedical applications.

4th International Conference Nanotechnology and Nanomaterials

CERN Document Server

Yatsenko, Leonid

2017-01-01

This book presents some of the latest achievements in nanotechnology and nanomaterials from leading researchers in Ukraine, Europe, and beyond. It features contributions from participants in the 4th International Science and Practice Conference Nanotechnology and Nanomaterials (NANO2016) held in Lviv, Ukraine on August 24-27, 2016. The International Conference was organized jointly by the Institute of Physics of the National Academy of Sciences of Ukraine, Ivan Franko National University of Lviv (Ukraine), University of Tartu (Estonia), University of Turin (Italy), and Pierre and Marie Curie University (France). Internationally recognized experts from a wide range of universities and research institutions share their knowledge and key results on topics ranging from nanooptics, nanoplasmonics, and interface studies to energy storage and biomedical applications. Presents cutting-edge advances in nanocomposites and carbon and silicon-based nanomaterials for a wide range of engineering and medical applications Co...

3rd International Conference Nanotechnology and Nanomaterials

CERN Document Server

Yatsenko, Leonid

2016-01-01

This book presents some of the latest achievements in nanotechnology and nanomaterials from leading researchers in Ukraine, Europe, and beyond. It features contributions from participants in the 3rd International Science and Practice Conference Nanotechnology and Nanomaterials (NANO2015) held in Lviv, Ukraine on August 26-30, 2015. The International Conference was organized jointly by the Institute of Physics of the National Academy of Sciences of Ukraine, University of Tartu (Estonia), Ivan Franko National University of Lviv (Ukraine), University of Turin (Italy), Pierre and Marie Curie University (France), and European Profiles A.E. (Greece). Internationally recognized experts from a wide range of universities and research institutions share their knowledge and key results on topics ranging from nanooptics, nanoplasmonics, and interface studies to energy storage and biomedical applications. Presents cutting-edge advances in nanocomposites and carbon and silicon-based nanomaterials for a wide range of engine...

Nitrogen deposition, land cover conversion, and contemporary carbon balance of Europe

Science.gov (United States)

Churkina, G.; Zaehle, S.; Hughes, J.; Viovy, N.; Jung, M.; Chen, Y.; Heimann, M.; Roedenbeck, C.; Jones, C.

2009-04-01

In Europe, atmospheric nitrogen deposition has more than doubled, forest cover was steadily increasing, and agricultural area was declining over the last 50 years. What effect have these changes had on the European carbon balance? In this study we estimate responses of the European land ecosystems to nitrogen deposition, land cover conversion and climate. We use results from four ecosystem process models such as BIOME-BGC, JULES, ORCHIDEE, and ORCHIDEE-CN to address this question. We discuss to which degree carbon balance of Europe has been altered by nitrogen deposition in comparison to other drivers and identify areas which carbon balance has been most effected by anthropogenic changes.

Electrode materials for microbial fuel cells: nanomaterial approach

KAUST Repository

Mustakeem, Mustakeem

2015-11-05

Microbial fuel cell (MFC) technology has the potential to become a major renewable energy resource by degrading organic pollutants in wastewater. The performance of MFC directly depends on the kinetics of the electrode reactions within the fuel cell, with the performance of the electrodes heavily influenced by the materials they are made from. A wide range of materials have been tested to improve the performance of MFCs. In the past decade, carbon-based nanomaterials have emerged as promising materials for both anode and cathode construction. Composite materials have also shown to have the potential to become materials of choice for electrode manufacture. Various transition metal oxides have been investigated as alternatives to conventional expensive metals like platinum for oxygen reduction reaction. In this review, different carbon-based nanomaterials and composite materials are discussed for their potential use as MFC electrodes.

Electrode materials for microbial fuel cells: nanomaterial approach

KAUST Repository

Mustakeem, Mustakeem

2015-01-01

Microbial fuel cell (MFC) technology has the potential to become a major renewable energy resource by degrading organic pollutants in wastewater. The performance of MFC directly depends on the kinetics of the electrode reactions within the fuel cell, with the performance of the electrodes heavily influenced by the materials they are made from. A wide range of materials have been tested to improve the performance of MFCs. In the past decade, carbon-based nanomaterials have emerged as promising materials for both anode and cathode construction. Composite materials have also shown to have the potential to become materials of choice for electrode manufacture. Various transition metal oxides have been investigated as alternatives to conventional expensive metals like platinum for oxygen reduction reaction. In this review, different carbon-based nanomaterials and composite materials are discussed for their potential use as MFC electrodes.

Surface science tools for nanomaterials characterization

CERN Document Server

2015-01-01

Fourth volume of a 40volume series on nano science and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about Surface Science Tools for Nanomaterials Characterization. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

Enhancing thermal conductivity of fluids with graphite nanoparticles and carbon nanotube

Science.gov (United States)

Zhang, Zhiqiang [Lexington, KY; Lockwood, Frances E [Georgetown, KY

2008-03-25

A fluid media such as oil or water, and a selected effective amount of carbon nanomaterials necessary to enhance the thermal conductivity of the fluid. One of the preferred carbon nanomaterials is a high thermal conductivity graphite, exceeding that of the neat fluid to be dispersed therein in thermal conductivity, and ground, milled, or naturally prepared with mean particle size less than 500 nm, and preferably less than 200 nm, and most preferably less than 100 nm. The graphite is dispersed in the fluid by one or more of various methods, including ultrasonication, milling, and chemical dispersion. Carbon nanotubes with graphitic structure is another preferred source of carbon nanomaterial, although other carbon nanomaterials are acceptable. To confer long term stability, the use of one or more chemical dispersants is preferred. The thermal conductivity enhancement, compared to the fluid without carbon nanomaterial, is proportional to the amount of carbon nanomaterials (carbon nanotubes and/or graphite) added.

Nanomaterials for practical functional uses

International Nuclear Information System (INIS)

Lines, M.G.

2008-01-01

The term nanotechnology, which enjoys wide public use, is a concept that covers a wide range of developments in the field of nanoscale electronic components, along with its decades-old application in nanocarbon-black particles or silicates manufactured using the sol-gel process. When we refer to nanotechnology today, the term is limited to dealing with particles or assemblies whose dimensions range in size from a few nanometres up to around 100 nm. Intensive development work is now being carried out in new fields in many industrial and university research facilities, with the help of nanoscale particles or subassemblies. Along with the already familiar items, this applications-oriented research has covered such new developments as carbon nanotubes or electronic circuits. All materials are composed of grains, which consist of many atoms. Grains of conventional materials vary in size from tens of microns to one or more millimetres. Nanomaterials are no longer merely a laboratory curiosity and have now reached the stage of commercialization being lead by activity, often government supported, in the USA, UK, Japan, Singapore, Malaysia, Taiwan, Korea, Germany and in recent years China and Australia. This is the opening of a whole new science in some respects, and the usefulness to our everyday lives will become increasingly apparent. The potential of nanominerals, as just one sector of nanomaterials technology have some very real and useful outcomes: ·Production of materials and products with new properties. ·Contribution to solutions of environmental problems. ·Improvement of existing technologies and development of new applications. ·Optimisation of primary conditions for practical applications. These materials are revolutionizing the functionality of material systems. Due to the materials very small size, they have some remarkable, and in some cases, novel properties. Significant enhancement of optical, mechanical, electrical, structural and magnetic properties

An overview of nanomaterials applied for removing dyes from wastewater.

Science.gov (United States)

Cai, Zhengqing; Sun, Youmin; Liu, Wen; Pan, Fei; Sun, Peizhe; Fu, Jie

2017-07-01

Organic dyes are one of the most commonly discharged pollutants in wastewaters; however, many conventional treatment methods cannot treat them effectively. Over the past few decades, we have witnessed rapid development of nanotechnologies, which offered new opportunities for developing innovative methods to treat dye-contaminated wastewater with low price and high efficiency. The large surface area, modified surface properties, unique electron conduction properties, etc. offer nanomaterials with excellent performances in dye-contaminated wastewater treatment. For examples, the agar-modified monometallic/bimetallic nanoparticles have the maximum methylene blue adsorption capacity of 875.0 mg/g, which are several times higher than conventional adsorbents. Among various nanomaterials, the carbonaceous nanomaterials, nano-sized TiO 2 , and graphitic carbon nitride (g-C 3 N 4 ) are considered as the most promising nanomaterials for removing dyes from water phase. However, some challenges, such as high cost and poor separation performance, still limit their engineering application. This article reviewed the recent advances in the nanomaterials used for dye removal via adsorption, photocatalytic degradation, and biological treatment. The modification methods for improving the effectiveness of nanomaterials are highlighted. Finally, the current knowledge gaps of developing nanomaterials on the environmental application were discussed, and the possible further research direction is proposed.

Applications of radiotracer techniques for the toxicology studies of nanomaterials

International Nuclear Information System (INIS)

Ma Yuhui; Zhang Zhiyong; Zhang Yuan; He Xiao; Zhang Haifeng; Chai Zhifang

2008-01-01

With the rapid development of nanosciences and nanotechnology, a wide variety of manufactured nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. While nanomaterials possess more novel and unique physicochemical properties than bulk materials, they also have an unpredictable impact on human health. In the toxicology studies of nanomaterials, it is essential to know the basic behaviors in vivo, that is absorption, distribution, metabolism, and excretion (ADME) of these newly designed materials. Radiotracer techniques are especially well suited to such studies and has got the chance to demonstrate its enchantment. In this presentation, studies on radiotracer techniques used in nanotoxicology will be reviewed and new progresses at Institute of High Energy Physics, including the label methods and behaviors of labeled nanomaterials, such as fullerene, carbon nanotubes, and nanometer metal oxide in animals and in aquatic environments will be reported. (authors)

Fabrication of Solid-State Gas Sensors by Drawing: An Undergraduate and High School Introduction to Functional Nanomaterials and Chemical Detection

Science.gov (United States)

Smith, Merry K.; Martin-Peralta, Daphnie G.; Pivak, Polina A.; Mirica, Katherine A.

2017-01-01

Carbon nanomaterials have promising utility in chemical sensing including applications in preserving occupational safety, monitoring of environmental pollution, and human health. While recent advances in device fabrication and molecular design of functional materials have enabled rapid fabrication of chemical sensors from carbon nanomaterials,…

Two-Dimensional Nanomaterials for Biomedical Applications: Emerging Trends and Future Prospects.

Science.gov (United States)

Chimene, David; Alge, Daniel L; Gaharwar, Akhilesh K

2015-12-02

Two-dimensional (2D) nanomaterials are ultrathin nanomaterials with a high degree of anisotropy and chemical functionality. Research on 2D nanomaterials is still in its infancy, with the majority of research focusing on elucidating unique material characteristics and few reports focusing on biomedical applications of 2D nanomaterials. Nevertheless, recent rapid advances in 2D nanomaterials have raised important and exciting questions about their interactions with biological moieties. 2D nanoparticles such as carbon-based 2D materials, silicate clays, transition metal dichalcogenides (TMDs), and transition metal oxides (TMOs) provide enhanced physical, chemical, and biological functionality owing to their uniform shapes, high surface-to-volume ratios, and surface charge. Here, we focus on state-of-the-art biomedical applications of 2D nanomaterials as well as recent developments that are shaping this emerging field. Specifically, we describe the unique characteristics that make 2D nanoparticles so valuable, as well as the biocompatibility framework that has been investigated so far. Finally, to both capture the growing trend of 2D nanomaterials for biomedical applications and to identify promising new research directions, we provide a critical evaluation of potential applications of recently developed 2D nanomaterials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advances in nanomaterials

CERN Document Server

Khan, Zishan

2016-01-01

This book provides a review of the latest research findings and key applications in the field of nanomaterials. The book contains twelve chapters on different aspects of nanomaterials. It begins with key fundamental concepts to aid readers new to the discipline of nanomaterials, and then moves to the different types of nanomaterials studied. The book includes chapters based on the applications of nanomaterials for nano-biotechnology and solar energy. Overall, the book comprises chapters on a variety of topics on nanomaterials from expert authors across the globe. This book will appeal to researchers and professional alike, and may also be used as a reference for courses in nanomaterials.

Advanced nanomaterials

Science.gov (United States)

Titus, Elby; Ventura, João; Pedro Araújo, João; Campos Gil, João

2017-12-01

Nanomaterials provide a remarkably novel outlook to the design and fabrication of materials. The know-how of designing, modelling and fabrication of nanomaterials demands sophisticated experimental and analytical techniques. The major impact of nanomaterials will be in the fields of electronics, energy and medicine. Nanoelectronics hold the promise of improving the quality of life of electronic devices through superior performance, weight reduction and lower power consumption. New energy production systems based on hydrogen, solar and nuclear sources have also benefited immensely from nanomaterials. In modern medicine, nanomaterials research will have great impact on public health care due to better diagnostic methods and design of novel drugs.

Carbon-based nanomaterial synthesis using nanosecond electrical discharges in immiscible layered liquids: n-heptane and water

KAUST Repository

Hamdan, Ahmad

2018-05-14

Plasmas in- or in-contact with liquids have been extensively investigated due to their high potential for a wide range of applications including but not limited to, water treatment, material synthesis and functionalization, bio-medical applications, and liquid fuel reformation. Recently, we successfully developed a discharge using two immiscible liquids, having very different electrical permittivities, which could significantly intensify the electric field intensity. Here, we establish nanosecond discharges at the interface n-heptane-water (with respective relative dielectric permittivities of 2 and 80) to enable the synthesis of carbon-based nanomaterials. A characterization of the as-synthesized material and the annealed (500 °C) material, using various techniques (Fourier-Transform, Infra-Red, Scanning and Transmission electron microscopes, etc.), shows that the as-synthesized material is a mixture of two carbon-based phases: a crystalline phase (graphite like) embedded into a phase of hydrogenated amorphous carbon. The existence of two-phases may be explained by the non-homogeneity of the discharge that induces various chemical reactions in the plasma channel.

Carbon-based nanomaterial synthesis using nanosecond electrical discharges in immiscible layered liquids: n-heptane and water

Science.gov (United States)

Hamdan, Ahmad; Cha, Min Suk

2018-06-01

Plasmas in- or in-contact with liquids have been extensively investigated due to their high potential for a wide range of applications including, but not limited to, water treatment, material synthesis and functionalization, bio-medical applications, and liquid fuel reformation. Recently, we successfully developed a discharge using two immiscible liquids, having very different electrical permittivities, which could significantly intensify the electric field intensity. Here, we establish nanosecond discharges at the interface n-heptane-water (with respective relative dielectric permittivities of 2 and 80) to enable the synthesis of carbon-based nanomaterials. A characterization of the as-synthesized material and the annealed (500 °C) material, using various techniques (Fourier-transform, infra-red, scanning and transmission electron microscopes, etc), shows that the as-synthesized material is a mixture of two carbon-based phases: a crystalline phase (graphite like) embedded into a phase of hydrogenated amorphous carbon. The existence of two-phases may be explained by the non-homogeneity of the discharge that induces various chemical reactions in the plasma channel.

Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes.

Science.gov (United States)

Wei, Hui; Wang, Erkang

2013-07-21

Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

Facile Synthesis of Carbon-Coated Zn2SnO4 Nanomaterials as Anode Materials for Lithium-Ion Batteries

Directory of Open Access Journals (Sweden)

Xiaoxu Ji

2014-01-01

Full Text Available Carbon-coated Zn2SnO4 nanomaterials have been synthesized by a facile hydrothermal method in which as-prepared Zn2SnO4 was used as the precursor and glucose as the carbon source. The structural, morphological, and electrochemical properties were investigated by means of X-ray (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and electrochemical measurement. The first discharge/charge capacity of carbon-coated Zn2SnO4 was about 1248.8 mAh/g and 873.2 mAh/g at a current density of 200 mA/g in the voltage range of 0.05 V–3.0 V, respectively, corresponding to Coulombic efficiency of 69.92%. After 40 cycles, the capacity retained 400 mAh/g, which is much better than bare Zn2SnO4.

Multimodal Magnetic-Plasmonic Nanoparticles for Biomedical Applications

Directory of Open Access Journals (Sweden)

Shelley Stafford

2018-01-01

Full Text Available Magnetic plasmonic nanomaterials are of great interest in the field of biomedicine due to their vast number of potential applications, for example, in molecular imaging, photothermal therapy, magnetic hyperthermia and as drug delivery vehicles. The multimodal nature of these nanoparticles means that they are potentially ideal theranostic agents—i.e., they can be used both as therapeutic and diagnostic tools. This review details progress in the field of magnetic-plasmonic nanomaterials over the past ten years, focusing on significant developments that have been made and outlining the future work that still needs to be done in this fast emerging area. The review describes the main synthetic approaches to each type of magnetic plasmonic nanomaterial and the potential biomedical applications of these hybrid nanomaterials.

Quantifying the Effects of Historical Land Cover Conversion Uncertainty on Global Carbon and Climate Estimates

Science.gov (United States)

Di Vittorio, A. V.; Mao, J.; Shi, X.; Chini, L.; Hurtt, G.; Collins, W. D.

2018-01-01

Previous studies have examined land use change as a driver of global change, but the translation of land use change into land cover conversion has been largely unconstrained. Here we quantify the effects of land cover conversion uncertainty on the global carbon and climate system using the integrated Earth System Model. Our experiments use identical land use change data and vary land cover conversions to quantify associated uncertainty in carbon and climate estimates. Land cover conversion uncertainty is large, constitutes a 5 ppmv range in estimated atmospheric CO2 in 2004, and generates carbon uncertainty that is equivalent to 80% of the net effects of CO2 and climate and 124% of the effects of nitrogen deposition during 1850-2004. Additionally, land cover uncertainty generates differences in local surface temperature of over 1°C. We conclude that future studies addressing land use, carbon, and climate need to constrain and reduce land cover conversion uncertainties.

Investigating the Toxicity and Environmental Fate of Graphene Nanomaterials

Science.gov (United States)

The Hersam Laboratory at Northwestern University works with the Center for Environmental Implications of Nanotechnology and the United States Environmental Protection Agency to study the toxicity and environmental fate of emergent nanomaterials, specifically carbon-based nanomate...

CE and nanomaterials - Part II: Nanomaterials in CE.

Science.gov (United States)

Adam, Vojtech; Vaculovicova, Marketa

2017-10-01

The scope of this two-part review is to summarize publications dealing with CE and nanomaterials together. This topic can be viewed from two broad perspectives, and this article is trying to highlight these two approaches: (i) CE of nanomaterials, and (ii) nanomaterials in CE. The second part aims at summarization of publications dealing with application of nanomaterials for enhancement of CE performance either in terms of increasing the separation resolution or for improvement of the detection. To increase the resolution, nanomaterials are employed as either surface modification of the capillary wall forming open tubular column or as additives to the separation electrolyte resulting in a pseudostationary phase. Moreover, nanomaterials have proven to be very beneficial for increasing also the sensitivity of detection employed in CE or even they enable the detection (e.g., fluorescent tags of nonfluorescent molecules). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The current state of engineered nanomaterials in consumer goods and waste streams: the need to develop nanoproperty-quantifiable sensors for monitoring engineered nanomaterials

Directory of Open Access Journals (Sweden)

Wise K

2011-07-01

Full Text Available Kelsey Wise, Murphy BrasuelDepartment of Chemistry and Biochemistry, Colorado College, Colorado Springs, CO, USAAbstract: As nanomaterials are harnessed for medicine and other technological advances, an understanding of the toxicology of these new materials is required to inform our use. This toxicological knowledge will be required to establish the medical and environmental regulations required to protect consumers and those involved in nanomaterial manufacturing. Nanoparticles of titanium oxide, carbon nanotubes, semiconductor quantum dots, gold, and silver represent a high percentage of the nanotechnology currently available or currently poised to reach consumers. For these nanoparticles, this review aims to identify current applications, the current methods used for characterization and quantification, current environmental concentrations (if known, and an introduction to the toxicology research. Continued development of analytical tools for the characterization and quantification of nanomaterials in complex environmental and biological samples will be required for our understanding of the toxicology and environmental impact of nanomaterials. Nearly all materials exhibit toxicity at a high enough concentration. Robust, rapid, and cost effective analytical techniques will be required to determine current background levels of anthropogenic, accidental, and engineered nanoparticles in air, water, and soil. The impact of the growing number of engineered nanoparticles used in consumer goods and medical applications can then be estimated. This will allow toxicological profiles relevant to the demonstrated or predicted environmental concentrations to be determined.Keywords: titanium dioxide nanoparticles, carbon nanotubes, semiconductor quantum dots, gold nanoparticles, silver nanoparticles, nanoparticles environmental concentrations

Degradation of Acid Orange 7 by peroxymonosulfate activated with the recyclable nanocomposites of g-C3N4 modified magnetic carbon.

Science.gov (United States)

Guo, Furong; Lu, Jiahua; Liu, Qing; Zhang, Ping; Zhang, Aiqing; Cai, Yingjie; Wang, Qiang

2018-08-01

Carbon-based catalysts have attracted high attention since they are greener and cheaper, while magnetic nanomaterials are very useful in environmental application because of the easy recovery and operation given by the magnetic separability. Therefore, graphitic carbon nitride modified magnetic carbon nanocomposites Fe 3 O 4 @C/g-C 3 N 4 was prepared herein for the first time as a new carbon-based catalyst for the activation of peroxymonosulfate (PMS). The catalytic properties of Fe 3 O 4 @C/g-C 3 N 4 in activating PMS for the degradation of Acid Orange 7 (AO 7), a model organic pollutant, were investigated. AO 7 degradation efficiency was significantly enhanced after modification of Fe 3 O 4 @C with g-C 3 N 4 , and the composite Fe 3 O 4 @C/g-C 3 N 4 from loading of 5 wt% g-C 3 N 4 and calcined at 300 °C for 30 min exhibited the best performance. AO 7 could be efficiently decolorized using the "Fe 3 O 4 @C/C 3 N 4 (5%) + PSM" system within the pH range of 2-6, and 97% of AO 7 could be removed in 20 min without pH adjustment (pH = 4). Radical quenching and EPR studies confirmed that both sulfate and hydroxyl radicals produced from PMS activation were the active species responsible for the oxidation of AO 7. The degradation mechanism was suggested based on the experimental results and XPS analyses. It was proposed that the CO groups on the carbon surface of Fe 3 O 4 @C rather than the CO in g-C 3 N 4 played a key role as the active sites for PMS activation. The catalyst was magnetically separable and displayed good stability and reusability, thus providing a potentially green catalyst for sustainable remediation of organic pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Functional DNA-containing nanomaterials: cellular applications in biosensing, imaging, and targeted therapy.

Science.gov (United States)

Liang, Hao; Zhang, Xiao-Bing; Lv, Yifan; Gong, Liang; Wang, Ruowen; Zhu, Xiaoyan; Yang, Ronghua; Tan, Weihong

2014-06-17

CONSPECTUS: DNA performs a vital function as a carrier of genetic code, but in the field of nanotechnology, DNA molecules can catalyze chemical reactions in the cell, that is, DNAzymes, or bind with target-specific ligands, that is, aptamers. These functional DNAs with different modifications have been developed for sensing, imaging, and therapeutic systems. Thus, functional DNAs hold great promise for future applications in nanotechnology and bioanalysis. However, these functional DNAs face challenges, especially in the field of biomedicine. For example, functional DNAs typically require the use of cationic transfection reagents to realize cellular uptake. Such reagents enter the cells, increasing the difficulty of performing bioassays in vivo and potentially damaging the cell's nucleus. To address this obstacle, nanomaterials, such as metallic, carbon, silica, or magnetic materials, have been utilized as DNA carriers or assistants. In this Account, we describe selected examples of functional DNA-containing nanomaterials and their applications from our recent research and those of others. As models, we have chosen to highlight DNA/nanomaterial complexes consisting of gold nanoparticles, graphene oxides, and aptamer-micelles, and we illustrate the potential of such complexes in biosensing, imaging, and medical diagnostics. Under proper conditions, multiple ligand-receptor interactions, decreased steric hindrance, and increased surface roughness can be achieved from a high density of DNA that is bound to the surface of nanomaterials, resulting in a higher affinity for complementary DNA and other targets. In addition, this high density of DNA causes a high local salt concentration and negative charge density, which can prevent DNA degradation. For example, DNAzymes assembled on gold nanoparticles can effectively catalyze chemical reactions even in living cells. And it has been confirmed that DNA-nanomaterial complexes can enter cells more easily than free single

Thermal stability of carbon-encapsulated Fe-Nd-B nanoparticles

International Nuclear Information System (INIS)

Bystrzejewski, M.; Cudzilo, S.; Huczko, A.; Lange, H.

2006-01-01

Thermal stability of various magnetic nanomaterials is very essential, due to their prospective future applications. In this paper, thermal behaviour of the carbon-encapsulated Fe-Nd-B nanoparticles is studied. These nanostructures were produced by direct current arcing of carbon anodes filled with Nd 2 Fe 14 B material. The thermogravimetry and differential thermal analysis curves were recorded in an oxygen atmosphere. The thermal processes were monitored by X-ray diffraction to follow the changes in the phase composition. The investigated samples have been thermally stable up to 600 K

A 3-dimensional in vitro model of epithelioid granulomas induced by high aspect ratio nanomaterials

Directory of Open Access Journals (Sweden)

Hurt Robert H

2011-05-01

Full Text Available Abstract Background The most common causes of granulomatous inflammation are persistent pathogens and poorly-degradable irritating materials. A characteristic pathological reaction to intratracheal instillation, pharyngeal aspiration, or inhalation of carbon nanotubes is formation of epithelioid granulomas accompanied by interstitial fibrosis in the lungs. In the mesothelium, a similar response is induced by high aspect ratio nanomaterials, including asbestos fibers, following intraperitoneal injection. This asbestos-like behaviour of some engineered nanomaterials is a concern for their potential adverse health effects in the lungs and mesothelium. We hypothesize that high aspect ratio nanomaterials will induce epithelioid granulomas in nonadherent macrophages in 3D cultures. Results Carbon black particles (Printex 90 and crocidolite asbestos fibers were used as well-characterized reference materials and compared with three commercial samples of multiwalled carbon nanotubes (MWCNTs. Doses were identified in 2D and 3D cultures in order to minimize acute toxicity and to reflect realistic occupational exposures in humans and in previous inhalation studies in rodents. Under serum-free conditions, exposure of nonadherent primary murine bone marrow-derived macrophages to 0.5 μg/ml (0.38 μg/cm2 of crocidolite asbestos fibers or MWCNTs, but not carbon black, induced macrophage differentiation into epithelioid cells and formation of stable aggregates with the characteristic morphology of granulomas. Formation of multinucleated giant cells was also induced by asbestos fibers or MWCNTs in this 3D in vitro model. After 7-14 days, macrophages exposed to high aspect ratio nanomaterials co-expressed proinflammatory (M1 as well as profibrotic (M2 phenotypic markers. Conclusions Induction of epithelioid granulomas appears to correlate with high aspect ratio and complex 3D structure of carbon nanotubes, not with their iron content or surface area. This model

Operationalization and application of “early warning signs” to screen nanomaterials for harmful properties operationalizationand application of “early warning signs” to screen nanomaterials for harmful properties

DEFF Research Database (Denmark)

Hansen, Steffen Foss; Nielsen, K. N.; Knudsen, N.

endeavors. This paper explores ho w the first lesson - “Acknowledge and respond to ignorance, uncertainty and risk in techn ology appraisal” could be applied to screen nanomaterials. In cases of ignorance, uncertainty a nd risk, the EEA recommends paying particular attention to important warning signs suc h...... as novelty, persistency, whether materials are readily dispersed in the environment, whether t hey bioaccumulate or lead to potentially irreversible action. Through an analysis of these c riteria using five well-known nanomaterials (titanium dioxide, carbon nanotubes, liposomes, pol y(lactic-co-glycolic acid....... Finally, we discuss how these warning sig ns can be used by different stakeholders such as nanomaterial researchers and developers, compani es and regulators to design benign nanomaterials, communicate what is known about nano -risks and decide on whether to implement precautionary regulatory measures....

Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

OpenAIRE

Rodr?guez, Jos? A.; Escamilla-Lara, Karen A.; Guevara-Lara, Alfredo; Miranda, Jose M.; P?ez-Hern?ndez, Ma. Elena

2015-01-01

A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30?mg?L?1, with a limit...

Calcium-Mediated Adhesion of Nanomaterials in Reservoir Fluids.

Science.gov (United States)

Eichmann, Shannon L; Burnham, Nancy A

2017-09-14

Globally, a small percentage of oil is recovered from reservoirs using primary and secondary recovery mechanisms, and thus a major focus of the oil industry is toward developing new technologies to increase recovery. Many new technologies utilize surfactants, macromolecules, and even nanoparticles, which are difficult to deploy in harsh reservoir conditions and where failures cause material aggregation and sticking to rock surfaces. To combat these issues, typically material properties are adjusted, but recent studies show that adjusting the dispersing fluid chemistry could have significant impact on material survivability. Herein, the effect of injection fluid salinity and composition on nanomaterial fate is explored using atomic force microscopy (AFM). The results show that the calcium content in reservoir fluids affects the interactions of an AFM tip with a calcite surface, as surrogates for nanomaterials interacting with carbonate reservoir rock. The extreme force sensitivity of AFM provides the ability to elucidate small differences in adhesion at the pico-Newton (pN) level and provides direct information about material survivability. Increasing the calcium content mitigates adhesion at the pN-scale, a possible means to increase nanomaterial survivability in oil reservoirs or to control nanomaterial fate in other aqueous environments.

Effect of reactor temperature on direct growth of carbon nanomaterials on stainless steel

Energy Technology Data Exchange (ETDEWEB)

Edzatty, A. N., E-mail: nuredzatty@gmail.com; Syazwan, S. M., E-mail: mdsyazwan.sanusi@gmail.com; Norzilah, A. H., E-mail: norzilah@unimap.edu.my; Jamaludin, S. B., E-mail: sbaharin@unimap.edu.my [Centre of Excellence for Frontier Materials Research, School of Materials Engineering, University Malaysia Perlis (Malaysia)

2016-07-19

Currently, carbon nanomaterials (CNMs) are widely used for various applications due to their extraordinary electrical, thermal and mechanical properties. In this work, CNMs were directly grown on the stainless steel (SS316) via chemical vapor deposition (CVD). Acetone was used as a carbon source and argon was used as carrier gas, to transport the acetone vapor into the reactor when the reaction occurred. Different reactor temperature such as 700, 750, 800, 850 and 900 °C were used to study their effect on CNMs growth. The growth time and argon flow rate were fixed at 30 minutes and 200 ml/min, respectively. Characterization of the morphology of the SS316 surface after CNMs growth using Scanning Electron Microscopy (SEM) showed that the diameter of grown-CNMs increased with the reactor temperature. Energy Dispersive X-ray (EDX) was used to analyze the chemical composition of the SS316 before and after CNMs growth, where the results showed that reduction of catalyst elements such as iron (Fe) and nickel (Ni) at high temperature (700 – 900 °C). Atomic Force Microscopy (AFM) analysis showed that the nano-sized hills were in the range from 21 to 80 nm. The best reactor temperature to produce CNMs was at 800 °C.

Reinforcement of cement-based matrices with graphite nanomaterials

Science.gov (United States)

Sadiq, Muhammad Maqbool

Cement-based materials offer a desirable balance of compressive strength, moisture resistance, durability, economy and energy-efficiency; their tensile strength, fracture energy and durability in aggressive environments, however, could benefit from further improvements. An option for realizing some of these improvements involves introduction of discrete fibers into concrete. When compared with today's micro-scale (steel, polypropylene, glass, etc.) fibers, graphite nanomaterials (carbon nanotube, nanofiber and graphite nanoplatelet) offer superior geometric, mechanical and physical characteristics. Graphite nanomaterials would realize their reinforcement potential as far as they are thoroughly dispersed within cement-based matrices, and effectively bond to cement hydrates. The research reported herein developed non-covalent and covalent surface modification techniques to improve the dispersion and interfacial interactions of graphite nanomaterials in cement-based matrices with a dense and well graded micro-structure. The most successful approach involved polymer wrapping of nanomaterials for increasing the density of hydrophilic groups on the nanomaterial surface without causing any damage to the their structure. The nanomaterials were characterized using various spectrometry techniques, and SEM (Scanning Electron Microscopy). The graphite nanomaterials were dispersed via selected sonication procedures in the mixing water of the cement-based matrix; conventional mixing and sample preparation techniques were then employed to prepare the cement-based nanocomposite samples, which were subjected to steam curing. Comprehensive engineering and durability characteristics of cement-based nanocomposites were determined and their chemical composition, microstructure and failure mechanisms were also assessed through various spectrometry, thermogravimetry, electron microscopy and elemental analyses. Both functionalized and non-functionalized nanomaterials as well as different

Biomedical Applications of Zinc Oxide Nanomaterials

Science.gov (United States)

Zhang, Yin; Nayak, Tapas R.; Hong, Hao; Cai, Weibo

2013-01-01

Nanotechnology has witnessed tremendous advancement over the last several decades. Zinc oxide (ZnO), which can exhibit a wide variety of nanostructures, possesses unique semiconducting, optical, and piezoelectric properties hence has been investigated for a wide variety of applications. One of the most important features of ZnO nanomaterials is low toxicity and biodegradability. Zn2+ is an indispensable trace element for adults (~10 mg of Zn2+ per day is recommended) and it is involved in various aspects of metabolism. Chemically, the surface of ZnO is rich in -OH groups, which can be readily functionalized by various surface decorating molecules. In this review article, we summarized the current status of the use of ZnO nanomaterials for biomedical applications, such as biomedical imaging (which includes fluorescence, magnetic resonance, positron emission tomography, as well as dual-modality imaging), drug delivery, gene delivery, and biosensing of a wide array of molecules of interest. Research in biomedical applications of ZnO nanomaterials will continue to flourish over the next decade, and much research effort will be needed to develop biocompatible/biodegradable ZnO nanoplatforms for potential clinical translation. PMID:24206130

The influence of carbon and oxygen on the magnetic characteristics of press-less sintered NdFeB magnets

International Nuclear Information System (INIS)

Xia, M.; Abrahamsen, A.B.; Bahl, C.R.H.; Veluri, B.; Søegaard, A.I.; Bøjsøe, P.; Millot, S.

2017-01-01

The Pressless Process (PLP) was adopted to manufacture NdFeB sintered magnets, where the investigations on carbon and oxygen residues from heptane milling liquid media and graphite crucibles used for sintering were quantified to evaluate the influence on the magnetic characteristics. The carbon and oxygen content in the magnets produced from wet ball milling of strip cast flakes was found to be of the order 10 4 ppm and 4·10 4 ppm respectively, which resulted in soft magnetic behavior. However using jet milling the carbon and oxygen concentration were decreased by an order of magnitude resulting in coercivity of up to 829 kA/m. Thus the influence of the carbon from the graphite crucibles is small. - Highlights: • It is found that the carbon from graphite crucibles will not influence the NdFeB. • The carbon from heptane mixed with NdFeB powder will react with the NdFeB, which breaks the magnetic properties of NdFeB. • Pressless process works well with graphite crucibles, without worrying that carbon has damage on magnets.

The influence of carbon and oxygen on the magnetic characteristics of press-less sintered NdFeB magnets

Energy Technology Data Exchange (ETDEWEB)

Xia, M., E-mail: maxi@dtu.dk [Department of Energy Conversion and Storage, DTU Risø Campus, Technical University of Denmark, Roskilde (Denmark); Abrahamsen, A.B. [Department of Wind Energy, DTU Risø campus, Technical University of Denmark, Roskilde (Denmark); Bahl, C.R.H. [Department of Energy Conversion and Storage, DTU Risø Campus, Technical University of Denmark, Roskilde (Denmark); Veluri, B.; Søegaard, A.I. [Grundfos A/S, DK-8850 Bjerringbro (Denmark); Bøjsøe, P. [Holm Magnetics APS, 2800 Kongens Lyngby (Denmark); Millot, S. [FJ Industries A/S, 5863 Ferritslev (Denmark)

2017-01-15

The Pressless Process (PLP) was adopted to manufacture NdFeB sintered magnets, where the investigations on carbon and oxygen residues from heptane milling liquid media and graphite crucibles used for sintering were quantified to evaluate the influence on the magnetic characteristics. The carbon and oxygen content in the magnets produced from wet ball milling of strip cast flakes was found to be of the order 10{sup 4} ppm and 4·10{sup 4} ppm respectively, which resulted in soft magnetic behavior. However using jet milling the carbon and oxygen concentration were decreased by an order of magnitude resulting in coercivity of up to 829 kA/m. Thus the influence of the carbon from the graphite crucibles is small. - Highlights: • It is found that the carbon from graphite crucibles will not influence the NdFeB. • The carbon from heptane mixed with NdFeB powder will react with the NdFeB, which breaks the magnetic properties of NdFeB. • Pressless process works well with graphite crucibles, without worrying that carbon has damage on magnets.

Magnetic properties of carbon-coated, ferromagnetic nanoparticles produced by a carbon-arc method

Science.gov (United States)

Brunsman, E. M.; Sutton, R.; Bortz, E.; Kirkpatrick, S.; Midelfort, K.; Williams, J.; Smith, P.; McHenry, M. E.; Majetich, S. A.; Artman, J. O.; De Graef, M.; Staley, S. W.

1994-05-01

The Krätschmer-Huffman carbon-arc method of preparing fullerenes has been used to generate carbon-coated transition metal (TM) and TM-carbide nanocrystallites. The magnetic nanocrystallites were extracted from the soot with a magnetic gradient field technique. For TM=Co the majority of nanocrystals exist as nominally spherical particles, 0.5-5 nm in radius. Hysteretic and temperature-dependent magnetic response, in randomly and magnetically aligned powder samples frozen in epoxy, correspond to fine particle magnetism associated with monodomain TM particles. The magnetization exhibits a unique functional dependence on H/T, and hysteresis below a blocking temperature TB. Below TB, the temperature dependence of the coercivity can be expressed as Hc=Hc0[1-(T/TB)1/2], where Hc0 is the 0 K coercivity.

Impact of humic/fulvic acid on the removal of heavy metals from aqueous solutions using nanomaterials: a review.

Science.gov (United States)

Tang, Wang-Wang; Zeng, Guang-Ming; Gong, Ji-Lai; Liang, Jie; Xu, Piao; Zhang, Chang; Huang, Bin-Bin

2014-01-15

Nowadays nanomaterials have been widely used to remove heavy metals from water/wastewater due to their large surface area and high reactivity. Humic acid (HA) and fulvic acid (FA) exist ubiquitously in aquatic environments and have a variety of functional groups which allow them to complex with metal ions and interact with nanomaterials. These interactions can not only alter the environmental behavior of nanomaterials, but also influence the removal and transportation of heavy metals by nanomaterials. Thus, the interactions and the underlying mechanisms involved warrant specific investigations. This review outlined the effects of HA/FA on the removal of heavy metals from aqueous solutions by various nanomaterials, mainly including carbon-based nanomaterials, iron-based nanomaterials and photocatalytic nanomaterials. Moreover, mechanisms involved in the interactions were discussed and potential environmental implications of HA/FA to nanomaterials and heavy metals were evaluated. © 2013.

Nanotechnology: Nanomaterials are Widely Used in Commerce, but EPA Faces Challenges in Regulating Risk

Science.gov (United States)

2010-05-01

549 Nanotechnology equivalent.17 In addition, nanotechnology -enabled water desalination and filtration systems may offer affordable...Senate NANOTECHNOLOGY Nanomaterials Are Widely Used in Commerce, but EPA Faces Challenges in Regulating Risk May 2010 GAO-10-549...2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Nanotechnology : Nanomaterials Are Widely Used in Commerce

Electrochemical immunosensors for the detection of survival motor neuron (SMN) protein using different carbon nanomaterials-modified electrodes.

Science.gov (United States)

Eissa, Shimaa; Alshehri, Nawal; Rahman, Anas M Abdel; Dasouki, Majed; Abu-Salah, Khalid M; Zourob, Mohammed

2018-03-15

Spinal muscular atrophy is an untreatable potentially fatal hereditary disorder caused by loss-of-function mutations in the survival motor neuron (SMN) 1 gene which encodes the SMN protein. Currently, definitive diagnosis relies on the demonstration of biallelic pathogenic variants in SMN1 gene. Therefore, there is an urgent unmet need to accurately quantify SMN protein levels for screening and therapeutic monitoring of symptomatic newborn and SMA patients, respectively. Here, we developed a voltammetric immunosensor for the sensitive detection of SMN protein based on covalently functionalized carbon nanofiber-modified screen printed electrodes. A comparative study of six different carbon nanomaterial-modified electrodes (carbon, graphene (G), graphene oxide (GO), single wall carbon nanotube (SWCNT), multi-wall carbon nanotube (MWCNT), and carbon nanofiber (CNF)) was performed. 4-carboxyphenyl layers were covalently grafted on the six electrodes by electroreduction of diazonium salt. Then, the terminal carboxylic moieties on the electrodes surfaces were utilized to immobilize the SMN antibody via EDC/NHS chemistry and to fabricate the immunosensors. The electrochemical characterization and analytical performance of the six immunosensors suggest that carbon nanofiber is a better electrode material for the SMN immunosensor. The voltammetric SMN carbon nanofiber-based immunosensor showed high sensitivity (detection limit of 0.75pg/ml) and selectivity against other proteins such as cystic fibrosis transmembrane conductance regulator (CFTR) and dystrophin (DMD). We suggest that this novel biosensor is superior to other developed assays for SMN detection in terms of lower cost, higher sensitivity, simplicity and capability of high throughput screening. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of nanomaterials in solar thermal energy storage

Science.gov (United States)

Shamshirgaran, Seyed Reza; Khalaji Assadi, Morteza; Viswanatha Sharma, Korada

2018-06-01

Solar thermal conversion technology harvests the sun's energy, rather than fossil fuels, to generate low-cost, low/zero-emission energy in the form of heating, cooling or electrical form for residential, commercial, and industrial sectors. The advent of nanofluids and nanocomposites or phase change materials, is a new field of study which is adapted to enhance the efficiency of solar collectors. The concepts of thermal energy storage technologies are investigated and the role of nanomaterials in energy conversion is discussed. This review revealed that although the exploitation of nanomaterials will boost the performance of solar collectors almost in all cases, this would be accompanied by certain challenges such as production cost, instability, agglomeration and erosion. Earlier studies have dealt with the enhancement of thermal conductivity and heat capacity; however, less attention has been given to the facing challenges. Moreover, no exact criteria can be found for the selection of appropriate nanomaterials and their properties for a specific application. In most research studies, the nanoparticles' material and properties have not been selected based on estimated values so that all the aspects of desired application could be considered simultaneously. The wide spread use of nanomaterials can lead to cost effective solutions as well. Therefore, it seems there should be a sense of techno-economic optimization in exploiting nanomaterials for solar thermal energy storage applications. The optimization should cover the key parameters, particularly nanoparticle type, size, loading and shape which depends on the sort of application and also dispersion technology.

Application of nanomaterials in solar thermal energy storage

Science.gov (United States)

Shamshirgaran, Seyed Reza; Khalaji Assadi, Morteza; Viswanatha Sharma, Korada

2017-12-01

Solar thermal conversion technology harvests the sun's energy, rather than fossil fuels, to generate low-cost, low/zero-emission energy in the form of heating, cooling or electrical form for residential, commercial, and industrial sectors. The advent of nanofluids and nanocomposites or phase change materials, is a new field of study which is adapted to enhance the efficiency of solar collectors. The concepts of thermal energy storage technologies are investigated and the role of nanomaterials in energy conversion is discussed. This review revealed that although the exploitation of nanomaterials will boost the performance of solar collectors almost in all cases, this would be accompanied by certain challenges such as production cost, instability, agglomeration and erosion. Earlier studies have dealt with the enhancement of thermal conductivity and heat capacity; however, less attention has been given to the facing challenges. Moreover, no exact criteria can be found for the selection of appropriate nanomaterials and their properties for a specific application. In most research studies, the nanoparticles' material and properties have not been selected based on estimated values so that all the aspects of desired application could be considered simultaneously. The wide spread use of nanomaterials can lead to cost effective solutions as well. Therefore, it seems there should be a sense of techno-economic optimization in exploiting nanomaterials for solar thermal energy storage applications. The optimization should cover the key parameters, particularly nanoparticle type, size, loading and shape which depends on the sort of application and also dispersion technology.

Nanomaterials for Electronics and Optoelectronics

Science.gov (United States)

Koehne, Jessica E.; Meyyappan, M.

2011-01-01

Nanomaterials such as carbon nanotubes(CNTs), graphene, and inorganic nanowires(INWs) have shown interesting electronic, mechanical, optical, thermal, and other properties and therefore have been pursued for a variety of applications by the nanotechnology community ranging from electronics to nanocomposites. While the first two are carbon-based materials, the INWs in the literature include silicon, germanium, III-V, II-VI, a variety of oxides, nitrides, antimonides and others. In this talk, first an overview of growth of these three classes of materials by CVD and PECVD will be presented along with results from characterization. Then applications in development of chemical sensors, biosensors, energy storage devices and novel memory architectures will be discussed.

Advanced Functional Nanomaterials for Biological Processes

Science.gov (United States)

2014-01-01

regeneration based on HA, gold nanoparticles, and graphene. We devised a one-step method in which Au and hydroxyapatite were used as a catalytic system in a...magnetic and spectroscopic properties. They were linked with targeting agents and used for successful Radio- Frequency (RF) driven thermal ablation of...State University (KSU). This work encompassed outstanding research at the nanostructural level and the use of advanced multifunctiona l nanomaterials in

Hybrid nanomaterial and its applications: IR sensing and energy harvesting

Science.gov (United States)

Tseng, Yi-Hsuan

In this dissertation, a hybrid nanomaterial, single-wall carbon nanotubes-copper sulfide nanoparticles (SWNTs-CuS NPs), was synthesized and its properties were analyzed. Due to its unique optical and thermal properties, the hybrid nanomaterial exhibited great potential for infrared (IR) sensing and energy harvesting. The hybrid nanomaterial was synthesized with the non-covalent bond technique to functionalize the surface of the SWNTs and bind the CuS nanoparticles on the surface of the SWNTs. For testing and analyzing the hybrid nanomaterial, SWNTs-CuS nanoparticles were formed as a thin film structure using the vacuum filtration method. Two conductive wires were bound on the ends of the thin film to build a thin film device for measurements and analyses. Measurements found that the hybrid nanomaterial had a significantly increased light absorption (up to 80%) compared to the pure SWNTs. Moreover, the hybrid nanomaterial thin film devices exhibited a clear optical and thermal switching effect, which could be further enhanced up to ten times with asymmetric illumination of light and thermal radiation on the thin film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials was demonstrated, indicating a new route for achieving thermoelectricity. In addition, CuS nanoparticles have great optical absorption especially in the near-infrared region. Therefore, the hybrid nanomaterial thin films also have the potential for IR sensing applications. The first application to be covered in this dissertation is the IR sensing application. IR thin film sensors based on the SWNTs-CuS nanoparticles hybrid nanomaterials were fabricated. The IR response in the photocurrent of the hybrid thin film sensor was significantly enhanced, increasing the photocurrent by 300% when the IR light illuminates the thin film device asymmetrically. The detection limit could be as low as 48mW mm-2. The dramatically enhanced

NaKnowBaseTM: The EPA Nanomaterials Research ...

Science.gov (United States)

The ability to predict the environmental and health implications of engineered nanomaterials is an important research priority due to the exponential rate at which nanotechnology is being incorporated into consumer, industrial and biomedical applications. To address this need and develop predictive capability, we have created the NaKnowbaseTM, which provides a platform for the curation and dissemination of EPA nanomaterials data to support functional assay development, hazard risk models and informatic analyses. To date, we have combined relevant physicochemical parameters from other organizations (e.g., OECD, NIST), with those requested for nanomaterial data submitted to EPA under the Toxic Substances Control Act (TSCA). Physiochemical characterization data were collated from >400 unique nanomaterials including metals, metal oxides, carbon-based and hybrid materials evaluated or synthesized by EPA researchers. We constructed parameter requirements and table structures for encoding research metadata, including experimental factors and measured response variables. As a proof of concept, we illustrate how SQL-based queries facilitate a range of interrogations including, for example, relationships between nanoparticle characteristics and environmental or toxicological endpoints. The views expressed in this poster are those of the authors and may not reflect U.S. EPA policy. The purpose of this submission for clearance is an abstract for submission to a scientific

Functional Carbon Nanocomposite, Optoelectronic, and Catalytic Coatings

Science.gov (United States)

Liang, Yu Teng

Over the past couple decades, fundamental research into carbon nanomaterials has produced a steady stream of groundbreaking physical science. Their record setting mechanical strength, chemical stability, and optoelectronic performance have fueled many optimistic claims regarding the breadth and pace of carbon nanotube and graphene integration. However, present synthetic, processing, and economic constraints have precluded these materials from many practical device applications. To overcome these limitations, novel synthetic techniques, processing methodologies, device geometries, and mechanistic insight were developed in this dissertation. The resulting advancements in material production and composite device performance have brought carbon nanomaterials ever closer to commercial implementation. For improved materials processing, vacuum co-deposition was first demonstrated as viable technique for forming carbon nanocomposite films without property distorting covalent modifications. Co-deposited nanoparticle, carbon nanotube, and graphene composite films enabled rapid device prototyping and compositional optimization. Cellulosic polymer stabilizers were then shown to be highly effective carbon nanomaterial dispersants, improving graphene production yields by two orders of magnitude in common organic solvents. By exploiting polarity interactions, iterative solvent exchange was used to further increase carbon nanomaterial dispersion concentrations by an additional order of magnitude, yielding concentrated inks. On top of their low causticity, these cellulosic nanomaterial inks have highly tunable viscosities, excellent film forming capacity, and outstanding thermal stability. These processing characteristics enable the efficient scaling of carbon nanomaterial coatings and device production using existing roll-to-roll fabrication techniques. Utilizing these process improvements, high-performance gas sensing, energy storage, transparent conductor, and photocatalytic

Exploring release and recovery of nanomaterials from commercial polymeric nanocomposites

International Nuclear Information System (INIS)

Busquets-Fité, Martí; Puntes, Víctor; Fernandez, Elisabet; Janer, Gemma; Vilar, Gemma; Vázquez-Campos, Socorro; Zanasca, R; Citterio, C; Mercante, L

2013-01-01

Much concern has been raised about the risks associated with the broad use of polymers containing nanomaterials. Much is known about degradation and aging of polymers and nanomaterials independently, but very few studies have been done in order to understand degradation of polymeric nanocomposites containing nanomaterials and the fate of these nanomaterials, which may occur in suffering many processes such as migration, release and physicochemical modifications. Throughout the UE funded FP7 project NANOPOLYTOX, studies on the migration, release and alteration of mechanical properties of commercial nanocomposites due to ageing and weathering have been performed along with studies on the feasibility of recovery and recycling of the nanomaterials. The project includes the use as model nanocomposites of Polyamide-6 (PA), Polypropylene (PP) and Ethyl Vinyl Acetate (EVA) as polymeric matrix filled with a 3% in mass of a set of selected broadly used nanomaterials; from inorganic metal oxides nanoparticles (SiO2, TiO2 and ZnO) to multi-walled carbon nanotubes (MWCNT) and Nanoclays. These model nanocomposites were then treated under accelerated ageing conditions in climatic chamber. To determine the degree of degradation of the whole nanocomposite and possible processes of migration, release and modification of the nanofillers, nanocomposites were characterized by different techniques. Additionally, recovery of the nanomaterials fro m the polymeric matrix was addressed, being successfully achieved for PA and PP based nanocomposites. In the case of PA, dissolution of the polymeric matrix using formic acid and further centrifugation steps was the chosen approach, while for PP based nanocomposites calcination was performed.

The Improvement of Dehydriding the Kinetics of NaMgH3 Hydride via Doping with Carbon Nanomaterials

Directory of Open Access Journals (Sweden)

Zhong-Min Wang

2016-12-01

Full Text Available NaMgH3 perovskite hydride and NaMgH3–carbon nanomaterials (NH-CM composites were prepared via the reactive ball-milling method. To investigate the catalytic effect of CM on the dehydriding kinetic properties of NaMgH3 hydride, multiwall carbon nanotubes (MWCNTs and graphene oxide (GO were used as catalytic additives. It was found that dehydriding temperatures and activation energies (ΔE1 and ΔE2 for two dehydrogenation steps of NaMgH3 hydride can be greatly reduced with a 5 wt. % CM addition. The NH–2.5M–2.5G composite presents better dehydriding kinetics, a lower dehydriding temperature, and a higher hydrogen-desorbed amount (3.64 wt. %, 638 K. ΔE1 and ΔE2 can be reduced by about 67 kJ/mol and 30 kJ/mol, respectively. The results suggest that the combination of MWCNTs and GO is a better catalyst as compared to MWCNTs or GO alone.

Bioinspired synthesis and self-assembly of hybrid organic–inorganic nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Zhang, Honghu [Iowa State Univ., Ames, IA (United States)

2016-12-17

Nature is replete with complex organic–inorganic hierarchical materials of diverse yet specific functions. These materials are intricately designed under physiological conditions through biomineralization and biological self-assembly processes. Tremendous efforts have been devoted to investigating mechanisms of such biomineralization and biological self-assembly processes as well as gaining inspiration to develop biomimetic methods for synthesis and self-assembly of functional nanomaterials. In this work, we focus on the bioinspired synthesis and self-assembly of functional inorganic nanomaterials templated by specialized macromolecules including proteins, DNA and polymers. The in vitro biomineralization process of the magnetite biomineralizing protein Mms6 has been investigated using small-angle X-ray scattering. Templated by Mms6, complex magnetic nanomaterials can be synthesized on surfaces and in the bulk. DNA and synthetic polymers have been exploited to construct macroscopic two- and three-dimensional (2D and 3D) superlattices of gold nanocrystals. Employing X-ray scattering and spectroscopy techniques, the self-assembled structures and the self-assembly mechanisms have been studied, and theoretical models have been developed. Our results show that specialized macromolecules including proteins, DNA and polymers act as effective templates for synthesis and self-assembly of nanomaterials. These bottom-up approaches provide promising routes to fabricate hybrid organic–inorganic nanomaterials with rationally designed hierarchical structures, targeting specific functions.

Modification of conductive polyaniline with carbon nanomaterials

Science.gov (United States)

Sedaghat, Sajjad; Alavijeh, Mahdi Soleimani

2014-08-01

The synthesis of polyaniline/single-wall nanotube, polyaniline/multi-wall nanotube and polyaniline/single-wall nanotube/graphen nanosheets nanocomposites by in situ polymerization are reported in this study. The substrates were treated with a mixture of concentrated sulfuric acid and concentrated nitric acid before usage to functionalize with carboxylic and hydroxyl groups. Aniline monomers are adsorbed and polymerized on the surface of these fillers. Structural analysis using scanning electron microscopy showed that nanomaterials dispersed into polymer matrix and made tubular structures with diameters several tens to hundreds nanometers depending on the polyaniline content. These nanocomposites can be used for production of excellent electrode materials applications in high-performance supercapacitors.

Magnetic study of iron-containing carbon nanotubes: Feasibility for magnetic hyperthermia

Energy Technology Data Exchange (ETDEWEB)

Krupskaya, Y. [Leibniz-Institute for Solid State and Materials Research IFW Dresden, 01171 Dresden (Germany)], E-mail: y.krupskaya@ifw-dresden.de; Mahn, C.; Parameswaran, A. [Leibniz-Institute for Solid State and Materials Research IFW Dresden, 01171 Dresden (Germany); Taylor, A.; Kraemer, K. [Department of Urology, Dresden University of Technology, 01307 Dresden (Germany); Hampel, S.; Leonhardt, A.; Ritschel, M.; Buechner, B.; Klingeler, R. [Leibniz-Institute for Solid State and Materials Research IFW Dresden, 01171 Dresden (Germany)

2009-12-15

We present a detailed magnetic study of iron containing carbon nanotubes (Fe-CNT), which highlights their potential for contactless magnetic heating in hyperthermia cancer treatment. Magnetic field dependent AC inductive heating experiments on Fe-CNT dispersions show a substantial temperature increase of Fe-CNT dispersions in applied AC magnetic fields. DC and AC magnetization studies have been done in order to elucidate the heating mechanism. We observe a different magnetic response of Fe-CNT powder compared to Fe-CNT dispersed in aqueous solution, e.g., ferromagnetic Fe-CNT in powder do not show any hysteresis when being dispersed in liquid. Our data indicate the motion of Fe-CNT in liquid in applied magnetic fields.

Defining Occupational and Consumer Exposure Limits for Nanomaterials – First Experiences from REACH Registrations

International Nuclear Information System (INIS)

Aschberger, K; Christensen, F M; Klöslova, Z; Falck, G

2013-01-01

By 1 December 2010 substances manufactured or imported in the EU ≥ 1000 t (as well as certain other substances) had to be registered under the REACH Regulation 1907/2006. The Joint Research Centre (JRC) in close cooperation with the European Chemicals Agency (ECHA) carried out an analysis and assessment of what type of information on nanomaterials was provided in the received registrations. The aim of the assessment was to develop options for an adaptation of the REACH regulation to ensure proper information generation and reporting and an appropriate risk/safety assessment of nanomaterials (Nano Support project). It should be noted that this analysis and assessment was not a compliance check of the dossiers. From 26000 submitted registration dossiers covering 4700 substances finally 25 dossiers (19 substances) were identified to cover nanomaterials or nanoforms of a substance. It is possible that other dossiers are considered to cover nanomaterials or nanoforms by the registrants, however such dossiers could not be identified to address nanoforms given the information contained in those dossiers. The identified 25 dossiers were subject to a detailed analysis and assessment of information provided for all endpoints including substance identity, physico-chemical properties, human health, environmental fate and behaviour, ecotoxicity, PBT 6 assessment, Classification and Labelling as well as the attached Chemical Safety Report documenting the Chemical Risk/Safety Assessment. In order to evaluate how the safety of workers and consumers was ensured, it was appropriate to check how the 'Derived No (Minimum) Effect Levels' (DN(M)ELs) were established for substances, covering nanomaterials or nanoforms. DNELs were established mainly for long term inhalation exposure of workers. Half of the assessed dossiers included an oral long term DNEL for the general population. DNELs were usually not specific for nanosized forms and, in the few cases where they were calculated for

Magnetic graphene sponge for the removal of methylene blue

International Nuclear Information System (INIS)

Yu, Baowei; Zhang, Xiaoliang; Xie, Jingru; Wu, Ruihan; Liu, Xiaoyang; Li, Hongliang; Chen, Fang; Yang, Hua; Ming, Zhu; Yang, Sheng-Tao

2015-01-01

Graphical abstract: - Highlights: • Magnetic graphene sponge is prepared for dye removal in aqueous solution. • Magnetic graphene sponge has an adsorption capacity of 526 mg/g for methylene blue. • Adsorption behaviors of methylene blue on magnetic graphene sponge are investigated. • Magnetic graphene sponge could be partially regenerated by washing with acidic ethanol. - Abstract: Magnetic carbon nanomaterials have been widely adopted as adsorbents in water treatment, but the low adsorption capacities largely limit their practical applications. In this study, magnetic graphene sponge (Fe 3 O 4 -GS) was prepared by lyophilization for the adsorption of dye pollutant. The incorporation of Fe 3 O 4 enabled the magnetic separation of Fe 3 O 4 -GS after the adsorption of methylene blue (MB). The adsorption capacity of Fe 3 O 4 -GS for MB was 526 mg/g, much higher than those of the magnetic carbon nanoadsorbents in the literature. The adsorption kinetics of MB on Fe 3 O 4 -GS was moderately fast, which could be analyzed by the pseudo-second-order model and intraparticle diffusion model. The thermodynamics study revealed that the adsorption was driven by the increased randomness on the interface. The pH and ionic strength had meaningful influences on the adsorption capacity of Fe 3 O 4 -GS. The facile regeneration of Fe 3 O 4 -GS would definitely reduce its operating cost. The implications to the environmental applications of magnetic carbon nanoadsorbents are discussed

Nitrogen deposition, land cover conversion, climate, and contemporary carbon balance of Europe (Invited)

Science.gov (United States)

Churkina, G.; Zahle, S.; Hughes, J.; Viovy, N.; Chen, Y.; Jung, M.; Ramankutty, N.; Roedenbeck, C.; Heimann, M.; Jones, C.

2009-12-01

In Europe, atmospheric nitrogen deposition has more than doubled, air temperature was rising, forest cover was steadily increasing, while agricultural area was declining over the last 50 years. What effect have these changes had on the European carbon balance? In this study we estimate responses of the European land ecosystems to nitrogen deposition, rising CO2, land cover conversion and climate change. We use results from three ecosystem process models such as BIOME-BGC, JULES, and ORCHIDEE (-CN) to address this question. We discuss to which degree carbon balance of Europe has been altered by nitrogen deposition in comparison to other drivers and identify areas which carbon balance has been affected by anthropogenic changes the most. We also analyze ecosystems carbon pools which were affected by the abovementioned environmental changes.

Bioengineered nanomaterials

CERN Document Server

Tiwari, Atul

2013-01-01

Many varieties of new, complex diseases are constantly being discovered, which leaves scientists with little choice but to embrace innovative methods for controlling the invasion of life-threatening problems. The use of nanotechnology has given scientists an opportunity to create nanomaterials that could help medical professionals in diagnosing and treating problems quickly and effectively. Bioengineered Nanomaterials presents in-depth information on bioengineered nanomaterials currently being developed in leading research laboratories around the world. In particular, the book focuses on nanom

A comparison of alumina, carbon and carbon-covered alumina as support for Ni-Mo-F additives: gas oil hydroprocessing studies

Energy Technology Data Exchange (ETDEWEB)

Boorman, P.M.; Kydd, R.A.; Sorensen, T.S.; Chong, K.; Lewis, J.M.; Bell, W.S. (University of Calgary, Calgary, AB (Canada). Dept. of Chemistry)

1991-01-01

Catalysts with 3 wt% NiO, 15 wt% MoO{sub 3} and 0-6.9 nominal wt% fluoride supported on alumina, carbon and carbon-covered alumina were studied to examine the role of fluoride and the influence of the support on hydroprocessing on Alberta gas oil. Experiments were carried out in a batch reactor at 410{degree}C and 6.9 MPa initial H{sub 2} pressure. It was found that fluoride promotion enhances cracking and hydrogenation reactions resulting in decreased aromatic and sulphur contents in the gas oil. The promotion is dependent on the type of support and is related to the strength of the fluoride-support interaction and the accessibility of the fluoride to the surface hydroxyl groups on the support. A maximum in activity at 3.6 wt% fluoride was observed for the alumina-supported catalysts whereas higher loadings of fluoride were required for carbon-covered alumina-supported catalysts to see an improvement over their carbon-supported counterparts. However, the carbon-covered alumina-supported catalysts seem to have a lower propensity for coke deposition than their alumina counterparts. 27 refs., 1 fig., 4 tabs.

A comparison of alumina, carbon and carbon-covered alumina as supports for Ni-Mo-F additives: gas oil hydroprocessing studies

Energy Technology Data Exchange (ETDEWEB)

Boorman, P.M.; Kydd, R.A.; Sorensen, T.S.; Chong, K.; Lewis, J.M.; Bell, W.S. (Calgary Univ., AB (Canada). Dept. of Chemistry)

1992-01-01

Catalysts with 3 wt% NiO, 15 wt% MoO{sub 3} and 0-6.9 nominal wt% fluoride supported on alumina, carbon and carbon-covered alumina were studied to examine the role of fluoride and the influence of the support on hydroprocessing on Alberta gas oil. Experiments were carried out in a batch reactor at 410{sup o}C and 6.9 MPa initial H{sub 2} pressure. It was found that fluoride promotion enhances cracking and hydrogenation reactions resulting in decreased aromatic and sulphur contents in the gas oil. The promotion is dependent on the type of support and is related to the strength of the fluoride-support interaction and the accessibility of the fluoride to the surface hydroxyl groups on the support. A maximum in activity at 3.6 wt% fluoride was observed for the alumina-supported catalysts whereas higher loadings of fluoride were required for carbon-covered alumina-supported catalysts to see an improvement over their carbon supported counterparts. However, the carbon-covered alumina supported catalysts seem to have a lower propensity for coke deposition than their alumina counterparts. (author).

Toxicology of Nanomaterials: Permanent interactive learning

Directory of Open Access Journals (Sweden)

Castranova Vince

2009-10-01

Full Text Available Abstract Particle and Fibre Toxicology wants to play a decisive role in a time where particle research is challenged and driven by the developments and applications of nanomaterials. This aim is not merely quantitative in publishing a given number of papers on nanomaterials, but also qualitatively since the field of nanotoxicology is rapidly emerging and benchmarks for good science are needed. Since then a number of things have happened that merit further analysis. The interactive learning issue is best shown by report and communications on the toxicology of multi-wall carbon nanotubes (CNT. A special workshop on the CNT has now been organized twice in Nagano (Japan and this editorial contains a summary of the most important outcomes. Finally, we take the opportunity discuss some recent reports from the nanotech literature, and more specifically a Chinese study that claims severe consequences of nanoparticle exposure.

Molecular toxicity of nanomaterials.

Science.gov (United States)

Chang, Xue-Ling; Yang, Sheng-Tao; Xing, Gengmei

2014-10-01

With the rapid developments in the fields of nanoscience and nanotechnlogy, more and more nanomaterials and their based consumer products have been used into our daily life. The safety concerns of nanomaterials have been well recognized by the scientific community and the public. Molecular mechanism of interactions between nanomaterials and biosystems is the most essential topic and final core of the biosafety. In the last two decades, nanotoxicology developed very fast and toxicity phenomena of nanomaterials have been reported. To achieve better understanding and detoxication of nanomaterials, thorough studies of nanotoxicity at molecular level are important. The interactions between nanomaterials and biomolecules have been widely investigated as the first step toward the molecular nanotoxicology. The consequences of such interactions have been discussed in the literature. Besides this, the chemical mechanism of nanotoxicology is gaining more attention, which would lead to a better design of nontoxic nanomaterials. In this review, we focus on the molecular nanotoxicology and explore the toxicity of nanomaterials at molecular level. The molecular level studies of nanotoxicology are summarized and the published nanotoxicological data are revisited.

MRI contrast enhancement using Magnetic Carbon Nanoparticles

Science.gov (United States)

Chaudhary, Rakesh P.; Kangasniemi, Kim; Takahashi, Masaya; Mohanty, Samarendra K.; Koymen, Ali R.; Department of Physics, University of Texas at Arlington Team; University of Texas Southwestern Medical Center Team

2014-03-01

In recent years, nanotechnology has become one of the most exciting forefront fields in cancer diagnosis and therapeutics such as drug delivery, thermal therapy and detection of cancer. Here, we report development of core (Fe)-shell (carbon) nanoparticles with enhanced magnetic properties for contrast enhancement in MRI imaging. These new classes of magnetic carbon nanoparticles (MCNPs) are synthesized using a bottom-up approach in various organic solvents, using the electric plasma discharge generated in the cavitation field of an ultrasonic horn. Gradient echo MRI images of well-dispersed MCNP-solutions (in tube) were acquired. For T2 measurements, a multi echo spin echo sequence was performed. From the slope of the 1/T2 versus concentration plot, the R2 value for different CMCNP-samples was measured. Since MCNPs were found to be extremely non-reactive, and highly absorbing in NIR regime, development of carbon-based MRI contrast enhancement will allow its simultaneous use in biomedical applications. We aim to localize the MCNPs in targeted tissue regions by external DC magnetic field, followed by MRI imaging and subsequent photothermal therapy.

Multiwalled carbon nanotube hybrids as MRI contrast agents

Directory of Open Access Journals (Sweden)

Nikodem Kuźnik

2016-07-01

Full Text Available Magnetic resonance imaging (MRI is one of the most commonly used tomography techniques in medical diagnosis due to the non-invasive character, the high spatial resolution and the possibility of soft tissue imaging. Contrast agents, such as gadolinium complexes and superparamagnetic iron oxides, are administered to spotlight certain organs and their pathologies. Many new models have been proposed that reduce side effects and required doses of these already clinically approved contrast agents. These new candidates often possess additional functionalities, e.g., the possibility of bioactivation upon action of particular stimuli, thus serving as smart molecular probes, or the coupling with therapeutic agents and therefore combining both a diagnostic and therapeutic role. Nanomaterials have been found to be an excellent scaffold for contrast agents, among which carbon nanotubes offer vast possibilities. The morphology of multiwalled carbon nanotubes (MWCNTs, their magnetic and electronic properties, the possibility of different functionalization and the potential to penetrate cell membranes result in a unique and very attractive candidate for a new MRI contrast agent. In this review we describe the different issues connected with MWCNT hybrids designed for MRI contrast agents, i.e., their synthesis and magnetic and dispersion properties, as well as both in vitro and in vivo behavior, which is important for diagnostic purposes. An introduction to MRI contrast agent theory is elaborated here in order to point to the specific expectations regarding nanomaterials. Finally, we propose a promising, general model of MWCNTs as MRI contrast agent candidates based on the studies presented here and supported by appropriate theories.

Towards Safer Nanomaterials

DEFF Research Database (Denmark)

Hjorth, Rune; Baun, Anders

2014-01-01

As nanomaterials become more widespread in everything from industrial processes to consumer products, concerns about human and environmental safety are being taken increasingly more seriously. In our research we are working with minimizing the impact and risks of engineered nanomaterials by looking...... or the exposure and optimally both. Examples include the 5 SAFER principles (Morose, 2010) or screenings of early warning signs (Hansen et al., 2013). Taking the full life cycle of nanomaterials into account, the principles of Green chemistry and Green engineering could also prove useful to reduce...... the environmental impact of nanomaterials (Eckelman et al., 2008). Our research interests include the feasibility of “safer-­‐by-­‐design” approaches, the production of greener nanomaterials and operationalization, adaption and creation of frameworks to facilitate safety engineering. Research and insight...

Grouping and Read-Across Approaches for Risk Assessment of Nanomaterials.

Science.gov (United States)

Oomen, Agnes G; Bleeker, Eric A J; Bos, Peter M J; van Broekhuizen, Fleur; Gottardo, Stefania; Groenewold, Monique; Hristozov, Danail; Hund-Rinke, Kerstin; Irfan, Muhammad-Adeel; Marcomini, Antonio; Peijnenburg, Willie J G M; Rasmussen, Kirsten; Jiménez, Araceli Sánchez; Scott-Fordsmand, Janeck J; van Tongeren, Martie; Wiench, Karin; Wohlleben, Wendel; Landsiedel, Robert

2015-10-26

Physicochemical properties of chemicals affect their exposure, toxicokinetics/fate and hazard, and for nanomaterials, the variation of these properties results in a wide variety of materials with potentially different risks. To limit the amount of testing for risk assessment, the information gathering process for nanomaterials needs to be efficient. At the same time, sufficient information to assess the safety of human health and the environment should be available for each nanomaterial. Grouping and read-across approaches can be utilised to meet these goals. This article presents different possible applications of grouping and read-across for nanomaterials within the broader perspective of the MARINA Risk Assessment Strategy (RAS), as developed in the EU FP7 project MARINA. Firstly, nanomaterials can be grouped based on limited variation in physicochemical properties to subsequently design an efficient testing strategy that covers the entire group. Secondly, knowledge about exposure, toxicokinetics/fate or hazard, for example via properties such as dissolution rate, aspect ratio, chemical (non-)activity, can be used to organise similar materials in generic groups to frame issues that need further attention, or potentially to read-across. Thirdly, when data related to specific endpoints is required, read-across can be considered, using data from a source material for the target nanomaterial. Read-across could be based on a scientifically sound justification that exposure, distribution to the target (fate/toxicokinetics) and hazard of the target material are similar to, or less than, the source material. These grouping and read-across approaches pave the way for better use of available information on nanomaterials and are flexible enough to allow future adaptations related to scientific developments.

Grouping and Read-Across Approaches for Risk Assessment of Nanomaterials

Directory of Open Access Journals (Sweden)

Agnes G. Oomen

2015-10-01

Full Text Available Physicochemical properties of chemicals affect their exposure, toxicokinetics/fate and hazard, and for nanomaterials, the variation of these properties results in a wide variety of materials with potentially different risks. To limit the amount of testing for risk assessment, the information gathering process for nanomaterials needs to be efficient. At the same time, sufficient information to assess the safety of human health and the environment should be available for each nanomaterial. Grouping and read-across approaches can be utilised to meet these goals. This article presents different possible applications of grouping and read-across for nanomaterials within the broader perspective of the MARINA Risk Assessment Strategy (RAS, as developed in the EU FP7 project MARINA. Firstly, nanomaterials can be grouped based on limited variation in physicochemical properties to subsequently design an efficient testing strategy that covers the entire group. Secondly, knowledge about exposure, toxicokinetics/fate or hazard, for example via properties such as dissolution rate, aspect ratio, chemical (non-activity, can be used to organise similar materials in generic groups to frame issues that need further attention, or potentially to read-across. Thirdly, when data related to specific endpoints is required, read-across can be considered, using data from a source material for the target nanomaterial. Read-across could be based on a scientifically sound justification that exposure, distribution to the target (fate/toxicokinetics and hazard of the target material are similar to, or less than, the source material. These grouping and read-across approaches pave the way for better use of available information on nanomaterials and are flexible enough to allow future adaptations related to scientific developments.

Silicon nanomaterials platform for bioimaging, biosensing, and cancer therapy.

Science.gov (United States)

Peng, Fei; Su, Yuanyuan; Zhong, Yiling; Fan, Chunhai; Lee, Shuit-Tong; He, Yao

2014-02-18

Silicon nanomaterials are an important class of nanomaterials with great potential for technologies including energy, catalysis, and biotechnology, because of their many unique properties, including biocompatibility, abundance, and unique electronic, optical, and mechanical properties, among others. Silicon nanomaterials are known to have little or no toxicity due to favorable biocompatibility of silicon, which is an important precondition for biological and biomedical applications. In addition, huge surface-to-volume ratios of silicon nanomaterials are responsible for their unique optical, mechanical, or electronic properties, which offer exciting opportunities for design of high-performance silicon-based functional nanoprobes, nanosensors, and nanoagents for biological analysis and detection and disease treatment. Moreover, silicon is the second most abundant element (after oxygen) on earth, providing plentiful and inexpensive resources for large-scale and low-cost preparation of silicon nanomaterials for practical applications. Because of these attractive traits, and in parallel with a growing interest in their design and synthesis, silicon nanomaterials are extensively investigated for wide-ranging applications, including energy, catalysis, optoelectronics, and biology. Among them, bioapplications of silicon nanomaterials are of particular interest. In the past decade, scientists have made an extensive effort to construct a silicon nanomaterials platform for various biological and biomedical applications, such as biosensors, bioimaging, and cancer treatment, as new and powerful tools for disease diagnosis and therapy. Nonetheless, there are few review articles covering these important and promising achievements to promote the awareness of development of silicon nanobiotechnology. In this Account, we summarize recent representative works to highlight the recent developments of silicon functional nanomaterials for a new, powerful platform for biological and

Price tag in nanomaterials?

Science.gov (United States)

Gkika, D. A.; Vordos, N.; Nolan, J. W.; Mitropoulos, A. C.; Vansant, E. F.; Cool, P.; Braet, J.

2017-05-01

With the evolution of the field of nanomaterials in the past number of years, it has become apparent that it will be key to future technological developments. However, while there are unlimited research undertakings on nanomaterials, limited research results on nanomaterial costs exist; all in spite of the generous funding that nanotechnology projects have received. There has recently been an exponential increase in the number of studies concerning health-related nanomaterials, considering the various medical applications of nanomaterials that drive medical innovation. This work aims to analyze the effect of the cost factor on acceptability of health-related nanomaterials independently or in relation to material toxicity. It appears that, from the materials studied, those used for cancer treatment applications are more expensive than the ones for drug delivery. The ability to evaluate cost implications improves the ability to undertake research mapping and develop opinions on nanomaterials that can drive innovation.

Magnetically recoverable nanocatalysts

KAUST Repository

Polshettiwar, Vivek

2011-05-11

A broad overview on magnetically recoverable nanocatalysts is presented and the use of magnetic nanomaterials as catalysts is discussed. Magnetic materials are used as organocatalysts and their applications range to challenging reactions, such as hydroformylation and olefin metathesis. Magnetic nanomaterials are also being used in environmental applications, such as for photo- and biocatalysis and for the adsorption and removal of pollutants from air and water. These materials show great promise as enantioselective catalysts, which are used extensively for the synthesis of medicines, drugs, and other bioactive molecules. By functionalizing these materials using chiral ligands, a series of chiral nanocatalysts can be designed, offering great potential to reuse these otherwise expensive catalyst systems. Characterization of magnetic catalysts is often a challenging task, and NMR characterization of these catalysts is difficult because the magnetic nature of the materials interferes with the magnetic field of the spectrometer.

Magnetically recoverable nanocatalysts

KAUST Repository

Polshettiwar, Vivek; Luque, Rafael L.; Fihri, Aziz; Zhu, Haibo; Bouhrara, Mohamed; Basset, Jean-Marie

2011-01-01

A broad overview on magnetically recoverable nanocatalysts is presented and the use of magnetic nanomaterials as catalysts is discussed. Magnetic materials are used as organocatalysts and their applications range to challenging reactions, such as hydroformylation and olefin metathesis. Magnetic nanomaterials are also being used in environmental applications, such as for photo- and biocatalysis and for the adsorption and removal of pollutants from air and water. These materials show great promise as enantioselective catalysts, which are used extensively for the synthesis of medicines, drugs, and other bioactive molecules. By functionalizing these materials using chiral ligands, a series of chiral nanocatalysts can be designed, offering great potential to reuse these otherwise expensive catalyst systems. Characterization of magnetic catalysts is often a challenging task, and NMR characterization of these catalysts is difficult because the magnetic nature of the materials interferes with the magnetic field of the spectrometer.

The influence of carbon and oxygen on the magnetic characteristics of press-less sintered NdFeB magnets

Science.gov (United States)

Xia, M.; Abrahamsen, A. B.; Bahl, C. R. H.; Veluri, B.; Søegaard, A. I.; Bøjsøe, P.; Millot, S.

2017-01-01

The Pressless Process (PLP) was adopted to manufacture NdFeB sintered magnets, where the investigations on carbon and oxygen residues from heptane milling liquid media and graphite crucibles used for sintering were quantified to evaluate the influence on the magnetic characteristics. The carbon and oxygen content in the magnets produced from wet ball milling of strip cast flakes was found to be of the order 104 ppm and 4·104 ppm respectively, which resulted in soft magnetic behavior. However using jet milling the carbon and oxygen concentration were decreased by an order of magnitude resulting in coercivity of up to 829 kA/m. Thus the influence of the carbon from the graphite crucibles is small.

X-ray and neutron techniques for nanomaterials characterization

CERN Document Server

2016-01-01

Fifth volume of a 40 volume series on nanoscience and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about X-ray and Neutron Techniques for Nanomaterials Characterization. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

Proceedings of the national conference on physics of engineering materials: souvenir cum abstract booklet

International Nuclear Information System (INIS)

Khasa, S.; Singh, Pradeep; Vinod Kumar

2013-01-01

The conference focusses on the contribution covering semiconducting materials and devices, magnetic nanomaterials and magnetic fluids, metals and alloys, advanced carbon products, polymers composites and soft materials, nuclear structure, proton radioactivity and clustering of nuclei, heavy ion induced nuclear reactions, accelerator and detector, hydrogen storage materials and fuel cells, liquid crystal, glasses and ceramic materials, high Tc superconducting materials, characterization of materials, thin films and sensors, biomedical applications of engineering materials, devices based application, renewable energy sources and applications. Papers relevant to INIS are indexed separately

Greener production of nanomaterials and their applications in catalysis and environmental remediation

Science.gov (United States)

Metal nanomaterials have attracted considerable attention because of their unique magnetic, optical, electrical, and catalytic properties and their potential applications in nanoelectronics. There is great interest in synthesizing metal nanoparticles due to their extraordinary pr...

Nanomaterials-based biosensors for detection of microorganisms and microbial toxins.

Science.gov (United States)

Sutarlie, Laura; Ow, Sian Yang; Su, Xiaodi

2017-04-01

Detection of microorganisms and microbial toxins is important for health and safety. Due to their unique physical and chemical properties, nanomaterials have been extensively used to develop biosensors for rapid detection of microorganisms with microbial cells and toxins as target analytes. In this paper, the design principles of nanomaterials-based biosensors for four selected analyte categories (bacteria cells, toxins, mycotoxins, and protozoa cells), closely associated with the target analytes' properties is reviewed. Five signal transducing methods that are less equipment intensive (colorimetric, fluorimetric, surface enhanced Raman scattering, electrochemical, and magnetic relaxometry methods) is described and compared for their sensory performance (in term oflimit of detection, dynamic range, and response time) for all analyte categories. In the end, the suitability of these five sensing principles for on-site or field applications is discussed. With a comprehensive coverage of nanomaterials, design principles, sensing principles, and assessment on the sensory performance and suitability for on-site application, this review offers valuable insight and perspective for designing suitable nanomaterials-based microorganism biosensors for a given application. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Removal of Pharmaceutical Compounds from Hospital Wastewaters Using Nanomaterials: A Review

Directory of Open Access Journals (Sweden)

Hasan Bagheri

2016-06-01

Full Text Available Over the past few years, residual pharmaceuticals (antibiotics, anticonvulsants, antipyretics drugs, hormones have begun to be considered as emerging environmental pollutants due to their continuous input and persistence to aquatic ecosystem even at low concentrations. Therefore, the development of efficient, cost-effective, and stable methods and materials for the wastewaters treatment have gained more recognition in recent years. In the path of meeting these developments, nanomaterials have attracted much attention as economical, convenient and ecofriendly tools for removing of pharmaceuticals from the hospital wastewaters because of their unique properties. The present review deals with recent advances in removal and/or destruction of residual pharmaceutical in wastewater samples using nanomaterials including metal nanoparticles, carbon nanotubes and nanofilters. In spite of using a variety of nanomaterials to remove the residual of pharmaceuticals, there is still a dearth of successful applicability of them in industrial processes. Therefore, some defects of nanomaterials to be used for the removal of pharmaceutical contaminate in environmental samples and their impacts on human health and environment is briefly discussed.

Comparing Seismic And Magnetic Responses To Copper Gold Deposits Under Different Cover Sequences

Directory of Open Access Journals (Sweden)

Okan Evans Onojasun

2015-08-01

Full Text Available Appropriate application of geophysical techniques is required to effectively explore through the cover sequences that will allow the discovery of deep seated orebodies within the 1-3km depth range. Whilst potential field methods that are traditionally used for Cu-Au exploration seems effective they lack the expected resolution required to detect deeper mineral deposits under 500 m cover. Seismic reflection techniques offers a distinct advantage over all other geophysical techniques because of its ability to penetrate deeper into the subsurface without losing its resolution. We present in this report modelling results from magnetic and seismic responses to Cu-Au deposits when located within 100-1000m depth range. In the case of magnetic modelling we apply upward continuation filters which calculate the potential field that would have been recorded at 100m 250m 500m and 1000 m levels by filtering away shallow anomalies from the initial data. For seismic modelling simple but realistic geological model with varying cover thicknesses 100m 250m 500m and 1000m were created and then populate these models with petrophysical data. Simulated synthetic seismic responses from the models was processed using basic processing flows to obtained depth migrated images. Results show that for shower depths 0-100m good correlation exist between the magnetic and the seismic responses. From 100-250m depth cover though we can still see some magnetic anomalies within the target zone its effectiveness decreases with depths whereas seismic responses was maintain within the depth range. From 500m to 1000m magnetic response becomes spear or fuzzy as much useful information is practically missed out. Similarly high resolution power of seismic was ably demonstrated as the depth of even 2km did not degrade its resolution. Thus both magnetic and seismic methods are very useful for shallow investigation but at greater depth seismic method appears to be a more valid exploration

Development of nano-particles labeled and enzyme free portable medical sensor

Energy Technology Data Exchange (ETDEWEB)

Uhm, Young Rang; Rhee, Chang Kyu; Lee, Min Ku; Kim, Jae Woo; Park, Jin Ju; Lee, Gung Ku; Lee, Gyoung Ja

2009-06-15

Development of the approach to the creation of new nonenzymatic biosensors based on immunocomplex 'antigen-antibody' using as signal generating compound Protein / Antibodies / Antigens, labeled with nanoparticles of metals, and using carbon containing nanomaterial as a transducer. Antigens of measles, forest-spring encephalitis or samonella serve as model systems. A technology for synthesis of magnetic Fe{sub 3}O{sub 4} nanoparticles with magnetite structure in 'nanoreactors' - inverse micelles - allowing the particle size regulation with in certain limit sand obtaining nanomaterials with reproducible properties was developed. A method for implementation of covered nanoparticles into microorganisms providing sorption of a reproducible number of nanoparticles on the cells was developed. A technology for production of conjugate of nanoparticles covered with polymeric layer with antibodies was developed.

Lanthanide-doped luminescent nanomaterials from fundamentals to bioapplications

CERN Document Server

Chen, Xueyuan; Tu, Datao

2014-01-01

Lanthanide-Doped Luminescent Nanomaterials reviews the latest advances in the development of lanthanide-doped luminescent inorganic nanoparticles for potential bioapplications. This book covers the chemical and physical fundamentals of these nanoparticles, such as the controlled synthesis methodology, surface modification chemistry, optical physics, and their promising applications in diverse bioassays, with an emphasis on heterogeneous and homogeneous in-vitro biodetection of tumor biomarkers. This book is intended for those readers who are interested in systematically understanding the materials design strategy, optical behavior of lanthanide ions, and practical bioapplications of lanthanide nanoparticles. It primarily focuses on the interdisciplinary frontiers in chemistry, physics and biological aspects of luminescent nanomaterials. All chapters were written by scientists active in this field and for a broad audience, providing both beginners and advanced researchers with comprehensive information on the ...

Simulating Exposure Concentrations of Engineered Nanomaterials in Surface Water Systems: Release of WASP8

Science.gov (United States)

Knightes, C. D.; Bouchard, D.; Zepp, R. G.; Henderson, W. M.; Han, Y.; Hsieh, H. S.; Avant, B. K.; Acrey, B.; Spear, J.

2017-12-01

The unique properties of engineered nanomaterials led to their increased production and potential release into the environment. Currently available environmental fate models developed for traditional contaminants are limited in their ability to simulate nanomaterials' environmental behavior. This is due to an incomplete understanding and representation of the processes governing nanomaterial distribution in the environment and by scarce empirical data quantifying the interaction of nanomaterials with environmental surfaces. The well-known Water Quality Analysis Simulation Program (WASP) was updated to incorporate nanomaterial-specific processes, specifically hetero-aggregation with particulate matter. In parallel with this effort, laboratory studies were used to quantify parameter values parameters necessary for governing processes in surface waters. This presentation will discuss the recent developments in the new architecture for WASP8 and the newly constructed Advanced Toxicant Module. The module includes advanced algorithms for increased numbers of state variables: chemicals, solids, dissolved organic matter, pathogens, temperature, and salinity. This presentation will focus specifically on the incorporation of nanomaterials, with the applications of the fate and transport of hypothetical releases of Multi-Walled Carbon Nanotubes (MWCNT) and Graphene Oxide (GO) into the headwaters of a southeastern US coastal plains river. While this presentation focuses on nanomaterials, the advanced toxicant module can also simulate metals and organic contaminants.

Application of dental nanomaterials: potential toxicity to the central nervous system.

Science.gov (United States)

Feng, Xiaoli; Chen, Aijie; Zhang, Yanli; Wang, Jianfeng; Shao, Longquan; Wei, Limin

2015-01-01

Nanomaterials are defined as materials with one or more external dimensions with a size of 1-100 nm. Such materials possess typical nanostructure-dependent properties (eg, chemical, biological, optical, mechanical, and magnetic), which may differ greatly from the properties of their bulk counterparts. In recent years, nanomaterials have been widely used in the production of dental materials, particularly in light polymerization composite resins and bonding systems, coating materials for dental implants, bioceramics, endodontic sealers, and mouthwashes. However, the dental applications of nanomaterials yield not only a significant improvement in clinical treatments but also growing concerns regarding their biosecurity. The brain is well protected by the blood-brain barrier (BBB), which separates the blood from the cerebral parenchyma. However, in recent years, many studies have found that nanoparticles (NPs), including nanocarriers, can transport through the BBB and locate in the central nervous system (CNS). Because the CNS may be a potential target organ of the nanomaterials, it is essential to determine the neurotoxic effects of NPs. In this review, possible dental nanomaterials and their pathways into the CNS are discussed, as well as related neurotoxicity effects underlying the in vitro and in vivo studies. Finally, we analyze the limitations of the current testing methods on the toxicological effects of nanomaterials. This review contributes to a better understanding of the nano-related risks to the CNS as well as the further development of safety assessment systems.

Intelligent Environmental Nanomaterials

KAUST Repository

Chang, Jian

2018-01-30

Due to the inherent complexity of environmental problems, especially water and air pollution, the utility of single-function environmental nanomaterials used in conventional and unconventional environmental treatment technologies are gradually reaching their limits. Intelligent nanomaterials with environmentally-responsive functionalities have shown potential to improve the performance of existing and new environmental technologies. By rational design of their structures and functionalities, intelligent nanomaterials can perform different tasks in response to varying application scenarios for the purpose of achieving the best performance. This review offers a critical analysis of the design concepts and latest progresses on the intelligent environmental nanomaterials in filtration membranes with responsive gates, materials with switchable wettability for selective and on-demand oil/water separation, environmental materials with self-healing capability, and emerging nanofibrous air filters for PM2.5 removal. We hope that this review will inspire further research efforts to develop intelligent environmental nanomaterials for the enhancement of the overall quality of environmental or human health.

Intelligent Environmental Nanomaterials

KAUST Repository

Chang, Jian; Zhang, Lianbin; Wang, Peng

2018-01-01

Due to the inherent complexity of environmental problems, especially water and air pollution, the utility of single-function environmental nanomaterials used in conventional and unconventional environmental treatment technologies are gradually reaching their limits. Intelligent nanomaterials with environmentally-responsive functionalities have shown potential to improve the performance of existing and new environmental technologies. By rational design of their structures and functionalities, intelligent nanomaterials can perform different tasks in response to varying application scenarios for the purpose of achieving the best performance. This review offers a critical analysis of the design concepts and latest progresses on the intelligent environmental nanomaterials in filtration membranes with responsive gates, materials with switchable wettability for selective and on-demand oil/water separation, environmental materials with self-healing capability, and emerging nanofibrous air filters for PM2.5 removal. We hope that this review will inspire further research efforts to develop intelligent environmental nanomaterials for the enhancement of the overall quality of environmental or human health.

UV-VIS and photoluminescence spectroscopy for nanomaterials characterization

CERN Document Server

2013-01-01

Second volume of a 40-volume series on nanoscience and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about UV-visible and photoluminescence spectroscopy for the characterization of nanomaterials. Modern applications and state-of-the-art techniques are covered and make this volume essential reading for research scientists in academia and industry in the related fields.

Magnetic graphene sponge for the removal of methylene blue

Energy Technology Data Exchange (ETDEWEB)

Yu, Baowei; Zhang, Xiaoliang; Xie, Jingru; Wu, Ruihan; Liu, Xiaoyang; Li, Hongliang; Chen, Fang; Yang, Hua; Ming, Zhu; Yang, Sheng-Tao, E-mail: yangst@pku.edu.cn

2015-10-01

Graphical abstract: - Highlights: • Magnetic graphene sponge is prepared for dye removal in aqueous solution. • Magnetic graphene sponge has an adsorption capacity of 526 mg/g for methylene blue. • Adsorption behaviors of methylene blue on magnetic graphene sponge are investigated. • Magnetic graphene sponge could be partially regenerated by washing with acidic ethanol. - Abstract: Magnetic carbon nanomaterials have been widely adopted as adsorbents in water treatment, but the low adsorption capacities largely limit their practical applications. In this study, magnetic graphene sponge (Fe{sub 3}O{sub 4}-GS) was prepared by lyophilization for the adsorption of dye pollutant. The incorporation of Fe{sub 3}O{sub 4} enabled the magnetic separation of Fe{sub 3}O{sub 4}-GS after the adsorption of methylene blue (MB). The adsorption capacity of Fe{sub 3}O{sub 4}-GS for MB was 526 mg/g, much higher than those of the magnetic carbon nanoadsorbents in the literature. The adsorption kinetics of MB on Fe{sub 3}O{sub 4}-GS was moderately fast, which could be analyzed by the pseudo-second-order model and intraparticle diffusion model. The thermodynamics study revealed that the adsorption was driven by the increased randomness on the interface. The pH and ionic strength had meaningful influences on the adsorption capacity of Fe{sub 3}O{sub 4}-GS. The facile regeneration of Fe{sub 3}O{sub 4}-GS would definitely reduce its operating cost. The implications to the environmental applications of magnetic carbon nanoadsorbents are discussed.

Intracellular signal modulation by nanomaterials.

Science.gov (United States)

Hussain, Salik; Garantziotis, Stavros; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Baeza-Squiban, Armelle; Boland, Sonja

2014-01-01

A thorough understanding of the interactions of nanomaterials with biological systems and the resulting activation of signal transduction pathways is essential for the development of safe and consumer friendly nanotechnology. Here we present an overview of signaling pathways induced by nanomaterial exposures and describe the possible correlation of their physicochemical characteristics with biological outcomes. In addition to the hierarchical oxidative stress model and a review of the intrinsic and cell-mediated mechanisms of reactive oxygen species (ROS) generating capacities of nanomaterials, we also discuss other oxidative stress dependent and independent cellular signaling pathways. Induction of the inflammasome, calcium signaling, and endoplasmic reticulum stress are reviewed. Furthermore, the uptake mechanisms can be of crucial importance for the cytotoxicity of nanomaterials and membrane-dependent signaling pathways have also been shown to be responsible for cellular effects of nanomaterials. Epigenetic regulation by nanomaterials, effects of nanoparticle-protein interactions on cell signaling pathways, and the induction of various cell death modalities by nanomaterials are described. We describe the common trigger mechanisms shared by various nanomaterials to induce cell death pathways and describe the interplay of different modalities in orchestrating the final outcome after nanomaterial exposures. A better understanding of signal modulations induced by nanomaterials is not only essential for the synthesis and design of safer nanomaterials but will also help to discover potential nanomedical applications of these materials. Several biomedical applications based on the different signaling pathways induced by nanomaterials are already proposed and will certainly gain a great deal of attraction in the near future.

Nanoscale interactions between engineered nanomaterials and black carbon (Biochar) in soil

Science.gov (United States)

Engineered nanomaterials (NMs) enter agricultural soils directly as additives in agrichemical formulations1 and indirectly as contaminants in municipal sewage sludge.2 NIFA has a vested interest in developing predictive models for the fate and nanotoxicity of NMs in agroecosystems. An understanding ...

Composite Materials with Magnetically Aligned Carbon Nanoparticles and Methods of Preparation

Science.gov (United States)

Hong, Haiping (Inventor); Peterson, G.P. (Bud) (Inventor); Salem, David R. (Inventor)

2018-01-01

The present invention relates to magnetically aligned carbon nanoparticle composites and methods of preparing the same. The composites comprise carbon nanoparticles, host material, magnetically sensitive nanoparticles and surfactant. The composites may have enhanced mechanical, thermal, and/or electrical properties.

A standardized non-instrumental tool for characterizing workstations concerned with exposure to engineered nanomaterials

Science.gov (United States)

Canu I, Guseva; C, Ducros; S, Ducamp; L, Delabre; S, Audignon-Durand; C, Durand; Y, Iwatsubo; D, Jezewski-Serra; Bihan O, Le; S, Malard; A, Radauceanu; M, Reynier; M, Ricaud; O, Witschger

2015-05-01

The French national epidemiological surveillance program EpiNano aims at surveying mid- and long-term health effects possibly related with occupational exposure to either carbon nanotubes or titanium dioxide nanoparticles (TiO2). EpiNano is limited to workers potentially exposed to these nanomaterials including their aggregates and agglomerates. In order to identify those workers during the in-field industrial hygiene visits, a standardized non-instrumental method is necessary especially for epidemiologists and occupational physicians unfamiliar with nanoparticle and nanomaterial exposure metrology. A working group, Quintet ExpoNano, including national experts in nanomaterial metrology and occupational hygiene reviewed available methods, resources and their practice in order to develop a standardized tool for conducting company industrial hygiene visits and collecting necessary information. This tool, entitled “Onsite technical logbook”, includes 3 parts: company, workplace, and workstation allowing a detailed description of each task, process and exposure surrounding conditions. This logbook is intended to be completed during the company industrial hygiene visit. Each visit is conducted jointly by an industrial hygienist and an epidemiologist of the program and lasts one or two days depending on the company size. When all collected information is computerized using friendly-using software, it is possible to classify workstations with respect to their potential direct and/or indirect exposure. Workers appointed to workstations classified as concerned with exposure are considered as eligible for EpiNano program and invited to participate. Since January 2014, the Onsite technical logbook has been used in ten company visits. The companies visited were mostly involved in research and development. A total of 53 workstations with potential exposure to nanomaterials were pre-selected and observed: 5 with TiO2, 16 with single-walled carbon nanotubes, 27 multiwalled

A standardized non-instrumental tool for characterizing workstations concerned with exposure to engineered nanomaterials

International Nuclear Information System (INIS)

I, Guseva Canu; S, Ducamp; L, Delabre; Y, Iwatsubo; D, Jezewski-Serra; C, Ducros; S, Audignon-Durand; C, Durand; O, Le Bihan; S, Malard; A, Radauceanu; M, Reynier; M, Ricaud; O, Witschger

2015-01-01

The French national epidemiological surveillance program EpiNano aims at surveying mid- and long-term health effects possibly related with occupational exposure to either carbon nanotubes or titanium dioxide nanoparticles (TiO 2 ). EpiNano is limited to workers potentially exposed to these nanomaterials including their aggregates and agglomerates. In order to identify those workers during the in-field industrial hygiene visits, a standardized non-instrumental method is necessary especially for epidemiologists and occupational physicians unfamiliar with nanoparticle and nanomaterial exposure metrology. A working group, Quintet ExpoNano, including national experts in nanomaterial metrology and occupational hygiene reviewed available methods, resources and their practice in order to develop a standardized tool for conducting company industrial hygiene visits and collecting necessary information. This tool, entitled “Onsite technical logbook”, includes 3 parts: company, workplace, and workstation allowing a detailed description of each task, process and exposure surrounding conditions. This logbook is intended to be completed during the company industrial hygiene visit. Each visit is conducted jointly by an industrial hygienist and an epidemiologist of the program and lasts one or two days depending on the company size. When all collected information is computerized using friendly-using software, it is possible to classify workstations with respect to their potential direct and/or indirect exposure. Workers appointed to workstations classified as concerned with exposure are considered as eligible for EpiNano program and invited to participate. Since January 2014, the Onsite technical logbook has been used in ten company visits. The companies visited were mostly involved in research and development. A total of 53 workstations with potential exposure to nanomaterials were pre-selected and observed: 5 with TiO 2 , 16 with single-walled carbon nanotubes, 27 multiwalled

Magnetic properties of carbon nanotubes with and without catalyst

Energy Technology Data Exchange (ETDEWEB)

Lipert, Kamil; Ritschel, Manfred; Leonhardt, Albrecht; Krupskaya, Yulia; Buechner, Bernd; Klingeler, Ruediger, E-mail: k.lipert@ifw-dresden.d [Leibniz Institute for Solid State and Materials Research (IFW) Dresden (Germany)

2010-01-01

In this paper we report on the magnetic properties of single- and multiwalled carbon nanotubes synthesized using different chemical vapour deposition methods and with variety of catalyst materials (ferromagnetic Fe, FeCo and diamagnetic Re). Different methods yield carbon nanotubes with different morphologies and different quantity of residual catalyst material. Catalyst particles are usually encapsulated in the nanotubes and influence the magnetic respond of the samples. Varying ferromagnetic properties depending on the shape, size and type of catalyst are discussed in detail. The data are compared with M(H) characteristics of carbon nanotubes without catalysts and with nonmagnetic rhenium, as a reference.

Photo-Responsive Graphene and Carbon Nanotubes to Control and Tackle Biological Systems

Science.gov (United States)

Cardano, Francesca; Frasconi, Marco; Giordani, Silvia

2018-01-01

Photo-responsive multifunctional nanomaterials are receiving considerable attention for biological applications because of their unique properties. The functionalization of the surface of carbon nanotubes (CNTs) and graphene, among other carbon based nanomaterials, with molecular switches that exhibit reversible transformations between two or more isomers in response to different kind of external stimuli, such as electromagnetic radiation, temperature and pH, has allowed the control of the optical and electrical properties of the nanomaterial. Light-controlled molecular switches, such as azobenzene and spiropyran, have attracted a lot of attention for nanomaterial's functionalization because of the remote modulation of their physicochemical properties using light stimulus. The enhanced properties of the hybrid materials obtained from the coupling of carbon based nanomaterials with light-responsive switches has enabled the fabrication of smart devices for various biological applications, including drug delivery, bioimaging and nanobiosensors. In this review, we highlight the properties of photo-responsive carbon nanomaterials obtained by the conjugation of CNTs and graphene with azobenzenes and spiropyrans molecules to investigate biological systems, devising possible future directions in the field. PMID:29707534

Submerged Glow-Discharge Plasma: An Economical Approach to Convert Construction Scrap Metal into Nanomaterials

Science.gov (United States)

Yek, Peter Nai Yuh; Rafiq Mirza Julaihi, Muhammad; Shahril Osman, Mohammad; Tiong, Tung Chuan; Lee, Wak Ha; Leing Lee, Chern

2018-03-01

Submerged glow-discharge plasma (SGDP) is relatively new among the various methods available for nanomaterials synthesis (NMs) techniques. This method allows great control over the production cost of nanomaterials synthesis. A lab-scale batch type SDGP technology has been constructed to produce nanomaterials and investigate the inter-relationship between plasma excitation voltages, electrodes submerged areas and electrolyte concentration. Metal oxide nanospheres has been synthesised from different electrolyte concentrations (1M-0.001M) and characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). As the major results showed that the nanospheres are uniformly spherical with diameter size distribution are between 100 nm - 2μm. EDS analysis shown the nano-Iron Oxide have been formed. Scrap metal initially showed around 6.45% and 93.55% of Carbon and Iron composition respectively. After SGDP process to the scrap metal, Carbon content has increased to 34-35% and Iron content has reduced to around 15-40%. EDS results also shown the higher percentage of Iron amount has remained with lower electrolyte concentration and Current is proportionally related to submersion area of cathode.

Plasmonic Nanomaterial-Based Optical Biosensing Platforms for Virus Detection

Directory of Open Access Journals (Sweden)

Jaewook Lee

2017-10-01

Full Text Available Plasmonic nanomaterials (P-NM are receiving attention due to their excellent properties, which include surface-enhanced Raman scattering (SERS, localized surface plasmon resonance (LSPR effects, plasmonic resonance energy transfer (PRET, and magneto optical (MO effects. To obtain such plasmonic properties, many nanomaterials have been developed, including metal nanoparticles (MNP, bimetallic nanoparticles (bMNP, MNP-decorated carbon nanotubes, (MNP-CNT, and MNP-modified graphene (MNP-GRP. These P-NMs may eventually be applied to optical biosensing systems due to their unique properties. Here, probe biomolecules, such as antibodies (Ab, probe DNA, and probe aptamers, were modified on the surface of plasmonic materials by chemical conjugation and thiol chemistry. The optical property change in the plasmonic nanomaterials was monitored based on the interaction between the probe biomolecules and target virus. After bioconjugation, several optical properties, including fluorescence, plasmonic absorbance, and diffraction angle, were changed to detect the target biomolecules. This review describes several P-NMs as potential candidates of optical sensing platforms and introduces various applications in the optical biosensing field.

Layer-by-Layer Assembled Nanotubes as Biomimetic Nanoreactors for Calcium Carbonate Deposition.

Science.gov (United States)

He, Qiang; Möhwald, Helmuth; Li, Junbai

2009-09-17

Enzyme-loaded magnetic polyelectrolyte multilayer nanotubes prepared by layer-by-layer assembly combined with the porous template could be used as biomimetic nanoreactors. It is demonstrated that calcium carbonate can be biomimetically synthesized inside the cavities of the polyelectrolyte nanotubes by the catalysis of urease, and the size of the calcium carbonate precipitates was controlled by the cavity dimensions. The metastable structure of the calcium carbonate precipitates inside the nanotubes was protected by the outer shell of the polyelectrolyte multilayers. These features may allow polyelectrolyte nanotubes to be applied in the fields of nanomaterials synthesis, controlled release, and drug delivery. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Review on the progress in synthesis and application of magnetic carbon nanocomposites

Science.gov (United States)

Zhu, Maiyong; Diao, Guowang

2011-07-01

This review focuses on the synthesis and application of nanostructured composites containing magnetic nanostructures and carbon-based materials. Great progress in fabrication of magnetic carbon nanocomposites has been made by developing methods including filling process, template-based synthesis, chemical vapor deposition, hydrothermal/solvothermal method, pyrolysis procedure, sol-gel process, detonation induced reaction, self-assembly method, etc. The applications of magnetic carbon nanocomposites expanded to a wide range of fields such as environmental treatment, microwave absorption, magnetic recording media, electrochemical sensor, catalysis, separation/recognization of biomolecules and drug delivery are discussed. Finally, some future trends and perspectives in this research area are outlined.

Exploring the Immunotoxicity of Carbon Nanotubes

Science.gov (United States)

Yu, Yanmei; Zhang, Qiu; Mu, Qingxin; Zhang, Bin; Yan, Bing

2008-08-01

Mass production of carbon nanotubes (CNTs) and their applications in nanomedicine lead to the increased exposure risk of nanomaterials to human beings. Although reports on toxicity of nanomaterials are rapidly growing, there is still a lack of knowledge on the potential toxicity of such materials to immune systems. This article reviews some existing studies assessing carbon nanotubes’ toxicity to immune system and provides the potential mechanistic explanation.

Magnetism for understanding catalyst analysis of purified carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Bellouard, Christine; Mercier, Guillaume; Cahen, Sébastien; Ghanbaja, Jaafar; Medjahdi, Ghouti [Institut Jean Lamour, CNRS-Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy (France); Gleize, Jérôme [Laboratoire de Chimie Physique-Approche Multi-échelle de Milieux Complexes-Université de Lorraine, 1 Bd Arago, 57078 Metz (France); Lamura, Gianrico [CNR-SPIN – Dipartimento di Fisica, via Dodecaneso 33, 16146 Genova (Italy); Hérold, Claire [Institut Jean Lamour, CNRS-Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy (France); Vigolo, Brigitte, E-mail: Brigitte.Vigolo@univ-lorraine.fr [Institut Jean Lamour, CNRS-Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy (France)

2016-08-01

The precise quantification of catalyst residues in purified carbon nanotubes is often a major issue in view of any fundamental and/or applicative studies. More importantly, since the best CNTs are successfully grown with magnetic catalysts, their quantification becomes strictly necessary to better understand intrinsic properties of CNT. For these reasons, we have deeply analyzed the catalyst content remained in nickel–yttrium arc-discharge single walled carbon nanotubes purified by both a chlorine-gas phase and a standard acid-based treatment. The study focuses on Ni analysis which has been investigated by transmission electron microscopy, X-ray diffraction, thermogravimetry analysis, and magnetic measurements. In the case of the acid-based treatment, all quantifications result in a decrease of the nanocrystallized Ni by a factor of two. In the case of the halogen gas treatment, analysis and quantification of Ni content is less straightforward: a huge difference appears between X-ray diffraction and thermogravimetry results. Thanks to magnetic measurements, this disagreement is explained by the presence of Ni{sup 2+} ions, belonging to NiCl{sub 2} formed during the Cl-based purification process. In particular, NiCl{sub 2} compound appears under different magnetic/crystalline phases: paramagnetic or diamagnetic, or well intercalated in between carbon sheets with an ordered magnetic phase at low temperature. - Highlights: • Cl-gas treatment of Ni catalyst of carbon nanotubes leads to NiCl{sub 2} residue. • Magnetic measurements show the transformation of Ni{sup 0} in Ni{sup 2+}through a purification process. • High temperature Cl treatment removes 75% of metallic impurities. • Cl-purification yields to an amount of metal of 1.5% in arc-discharge CNT samples.

Pulmonary toxicity of nanomaterials: a critical comparison of published in vitro assays and in vivo inhalation or instillation studies.

Science.gov (United States)

Landsiedel, Robert; Sauer, Ursula G; Ma-Hock, Lan; Schnekenburger, Jürgen; Wiemann, Martin

2014-11-01

To date, guidance on how to incorporate in vitro assays into integrated approaches for testing and assessment of nanomaterials is unavailable. In addressing this shortage, this review compares data from in vitro studies to results from in vivo inhalation or intratracheal instillation studies. Globular nanomaterials (ion-shedding silver and zinc oxide, poorly soluble titanium dioxide and cerium dioxide, and partly soluble amorphous silicon dioxide) and nanomaterials with higher aspect ratios (multiwalled carbon nanotubes) were assessed focusing on the Organisation for Economic Co-Operation and Development (OECD) reference nanomaterials for these substances. If in vitro assays are performed with dosages that reflect effective in vivo dosages, the mechanisms of nanomaterial toxicity can be assessed. In early tiers of integrated approaches for testing and assessment, knowledge on mechanisms of toxicity serves to group nanomaterials thereby reducing the need for animal testing.

Insights into biogenic and chemical production of inorganic nanomaterials and nanostructures.

Science.gov (United States)

Faramarzi, Mohammad Ali; Sadighi, Armin

2013-03-01

The synthesis of inorganic nanomaterials and nanostructures by the means of diverse physical, chemical, and biological principles has been developed in recent decades. The nanoscale materials and structures creation continue to be an active area of researches due to the exciting properties of the resulting nanomaterials and their innovative applications. Despite physical and chemical approaches which have been used for a long time to produce nanomaterials, biological resources as green candidates that can replace old production methods have been focused in recent years to generate various inorganic nanoparticles (NPs) or other nanoscale structures. Cost-effective, eco-friendly, energy efficient, and nontoxic produced nanomaterials using diverse biological entities have been received increasing attention in the last two decades in contrast to physical and chemical methods owe using toxic solvents, generate unwanted by-products, and high energy consumption which restrict the popularity of these ways employed in nanometric science and engineering. In this review, the biosynthesis of gold, silver, gold-silver alloy, magnetic, semiconductor nanocrystals, silica, zirconia, titania, palladium, bismuth, selenium, antimony sulfide, and platinum NPs, using bacteria, actinomycetes, fungi, yeasts, plant extracts and also informational bio-macromolecules including proteins, polypeptides, DNA, and RNA have been reported extensively to mention the current status of the biological inorganic nanomaterial production. In other hand, two well-known wet chemical techniques, namely chemical reduction and sol-gel methods, used to produce various types of nanocrystalline powders, metal oxides, and hybrid organic-inorganic nanomaterials have presented. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterisation of nanomaterial hydrophobicity using engineered surfaces

Energy Technology Data Exchange (ETDEWEB)

Desmet, Cloé; Valsesia, Andrea; Oddo, Arianna; Ceccone, Giacomo; Spampinato, Valentina; Rossi, François; Colpo, Pascal, E-mail: pascal.colpo@ec.europa.eu [Directorate Health, Consumer and Reference Materials, Consumer Products Safety Unit (Italy)

2017-03-15

Characterisation of engineered nanomaterials (NMs) is of outmost importance for the assessment of the potential risks arising from their extensive use. NMs display indeed a large variety of physico-chemical properties that drastically affect their interaction with biological systems. Among them, hydrophobicity is an important property that is nevertheless only slightly covered by the current physico-chemical characterisation techniques. In this work, we developed a method for the direct characterisation of NM hydrophobicity. The determination of the nanomaterial hydrophobic character is carried out by the direct measurement of the affinity of the NMs for different collectors. Each collector is an engineered surface designed in order to present specific surface charge and hydrophobicity degrees. Being thus characterised by a combination of surface energy components, the collectors enable the NM immobilisation with surface coverage in relation to their hydrophobicity. The experimental results are explained by using the extended DLVO theory, which takes into account the hydrophobic forces acting between NMs and collectors.

Advanced Nanomaterials for High-Efficiency Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Chen, Junhong [University of Wisconsin-Milwaukee

2013-11-29

Energy supply has arguably become one of the most important problems facing humankind. The exponential demand for energy is evidenced by dwindling fossil fuel supplies and record-high oil and gas prices due to global population growth and economic development. This energy shortage has significant implications to the future of our society, in addition to the greenhouse gas emission burden due to consumption of fossil fuels. Solar energy seems to be the most viable choice to meet our clean energy demand given its large scale and clean/renewable nature. However, existing methods to convert sun light into electricity are not efficient enough to become a practical alternative to fossil fuels. This DOE project aims to develop advanced hybrid nanomaterials consisting of semiconductor nanoparticles (quantum dots or QDs) supported on graphene for cost-effective solar cells with improved conversion efficiency for harvesting abundant, renewable, clean solar energy to relieve our global energy challenge. Expected outcomes of the project include new methods for low-cost manufacturing of hybrid nanostructures, systematic understanding of their properties that can be tailored for desired applications, and novel photovoltaic cells. Through this project, we have successfully synthesized a number of novel nanomaterials, including vertically-oriented graphene (VG) sheets, three-dimensional (3D) carbon nanostructures comprising few-layer graphene (FLG) sheets inherently connected with CNTs through sp{sup 2} carbons, crumpled graphene (CG)-nanocrystal hybrids, CdSe nanoparticles (NPs), CdS NPs, nanohybrids of metal nitride decorated on nitrogen-doped graphene (NG), QD-carbon nanotube (CNT) and QD-VG-CNT structures, TiO{sub 2}-CdS NPs, and reduced graphene oxide (RGO)-SnO{sub 2} NPs. We further assembled CdSe NPs onto graphene sheets and investigated physical and electronic interactions between CdSe NPs and the graphene. Finally we have demonstrated various applications of these

A multi-endpoint, high-throughput study of nanomaterial toxicity in Caenorhabditis elegans

Science.gov (United States)

Jung, Sang-Kyu; Qu, Xiaolei; Aleman-Meza, Boanerges; Wang, Tianxiao; Riepe, Celeste; Liu, Zheng; Li, Qilin; Zhong, Weiwei

2015-01-01

The booming nanotech industry has raised public concerns about the environmental health and safety impact of engineered nanomaterials (ENMs). High-throughput assays are needed to obtain toxicity data for the rapidly increasing number of ENMs. Here we present a suite of high-throughput methods to study nanotoxicity in intact animals using Caenorhabditis elegans as a model. At the population level, our system measures food consumption of thousands of animals to evaluate population fitness. At the organism level, our automated system analyzes hundreds of individual animals for body length, locomotion speed, and lifespan. To demonstrate the utility of our system, we applied this technology to test the toxicity of 20 nanomaterials under four concentrations. Only fullerene nanoparticles (nC60), fullerol, TiO2, and CeO2 showed little or no toxicity. Various degrees of toxicity were detected from different forms of carbon nanotubes, graphene, carbon black, Ag, and fumed SiO2 nanoparticles. Aminofullerene and UV irradiated nC60 also showed small but significant toxicity. We further investigated the effects of nanomaterial size, shape, surface chemistry, and exposure conditions on toxicity. Our data are publicly available at the open-access nanotoxicity database www.QuantWorm.org/nano. PMID:25611253

Handbook of nanomaterials properties

CERN Document Server

Luo, Dan; Schricker, Scott R; Sigmund, Wolfgang; Zauscher, Stefan

2014-01-01

Nanomaterials attract tremendous attention in recent researches. Although extensive research has been done in this field it still lacks a comprehensive reference work that presents data on properties of different Nanomaterials. This Handbook of Nanomaterials Properties will be the first single reference work that brings together the various properties with wide breadth and scope.

Carbon-Based Materials for Photo-Triggered Theranostic Applications

Directory of Open Access Journals (Sweden)

Karunya Albert

2016-11-01

Full Text Available Carbon-based nanomaterials serve as a type of smart material for photo-triggered disease theranostics. The inherent physicochemical properties of these nanomaterials facilitate their use for less invasive treatments. This review summarizes the properties and applications of materials including fullerene, nanotubes, nanohorns, nanodots and nanographenes for photodynamic nanomedicine in cancer and antimicrobial therapies. Carbon nanomaterials themselves do not usually act as photodynamic therapy (PDT agents owing to the high hydrophobicity, however, when the surface is passivated or functionalized, these materials become great vehicles for PDT. Moreover, conjugation of carbonaceous nanomaterials with the photosensitizer (PS and relevant targeting ligands enhances properties such as selectivity, stability, and high quantum yield, making them readily available for versatile biomedical applications.

The review of patents in the area of nanotechnologies and nanomaterials. Part 3

Directory of Open Access Journals (Sweden)

VLASOV Vladimir Alexeevich

2015-10-01

Full Text Available The inventions in the area of nanotechnologies and nanomaterials produce a profound effect in construction, housing and communal services and adjacent economic fields. The invention «The method to produce body of oriented carbon nanotubes on the surface of base plate (RU 2561616» refers to the technologies for production of body of carbon nanotubes on the surface of base plate. The flow of actuation gas is formed in the reaction chamber. The flow contains carrying gas, gas hydrocarbon and predecessor of catalyst for synthesis of carbon nanotubes. In some cases, when implementing invention, the flow of inert gas is directed to the surface of the base plate. This gas flow shades the zone of synthesis of carbon nanotubes from air when its pressure exceeds the pressure of actuation gas flow. The method provides the body of oriented carbon nanotubes on the base plates with big surface: up to several square metres. The invention «Composition of mixture for asphaltic concrete (RU 2561435» refers to the construction production in highway industry and can be applied in manufacture of asphaltic concrete including nanotechnologies. The specialists may be also interested in the following nanotechnological inventions: the method to modify carbon nanomaterials (RU 2548083; nanofiber polymer material (RU 2543377; the method to produce nanosuspensions for manufacture of polymer nanocomposite (RU 2500695; the method to strengthen metal products to obtain nanostructured surface layers (RU 2527511; the method to form heat-resistant nanocomposite coating on the surface of the products made of heat-resistant nickel alloys (RU 2549813; the method to apply nanodiamond material by means of combined electromechanical treatment (RU 2530432; the method to produce soot with content of fullerens and nanotubes made of gas carbon raw material (RU 2531291; the method to produce powders of zinc oxide with surface modification for usage in construction sealing materials (RU

The influence of carbon and oxygen on the magnetic characteristics of press-less sintered NdFeB magnets

DEFF Research Database (Denmark)

Xia, Manlong; Abrahamsen, Asger Bech; Bahl, Christian

2017-01-01

The Pressless Process (PLP) was adopted to manufacture NdFeB sintered magnets, where the investigations on carbon and oxygen residues from heptane milling liquid media and graphite crucibles used for sintering were quantified to evaluate the influence on the magnetic characteristics. The carbon...

Modification of the Interfacial Interaction between Carbon Fiber and Epoxy with Carbon Hybrid Materials

Directory of Open Access Journals (Sweden)

Kejing Yu

2016-05-01

Full Text Available The mechanical properties of the hybrid materials and epoxy and carbon fiber (CF composites were improved significantly as compared to the CF composites made from unmodified epoxy. The reasons could be attributed to the strong interfacial interaction between the CF and the epoxy composites for the existence of carbon nanomaterials. The microstructure and dispersion of carbon nanomaterials were characterized by transmission electron microscopy (TEM and optical microscopy (OM. The results showed that the dispersion of the hybrid materials in the polymer was superior to other carbon nanomaterials. The high viscosity and shear stress characterized by a rheometer and the high interfacial friction and damping behavior characterized by dynamic mechanical analysis (DMA indicated that the strong interfacial interaction was greatly improved between fibers and epoxy composites. Remarkably, the tensile tests presented that the CF composites with hybrid materials and epoxy composites have a better reinforcing and toughening effect on CF, which further verified the strong interfacial interaction between epoxy and CF for special structural hybrid materials.

2nd international conference on advanced nanomaterials and nanotechnology

CERN Document Server

Goswami, D; Perumal, A

2013-01-01

Nanoscale science and technology have occupied centre stage globally in modern scientific research and discourses in the early twenty first century. The enabling nature of the technology makes it important in modern electronics, computing, materials, healthcare, energy and the environment. This volume contains selected articles presented (as Invited/Oral/Poster presentations) at the 2nd international conference on advanced materials and nanotechnology (ICANN-2011) held recently at the Indian Institute of Technology Guwahati, during Dec 8-10, 2011. The list of topics covered in this proceedings include: Synthesis and self assembly of nanomaterials Nanoscale characterisation Nanophotonics & Nanoelectronics Nanobiotechnology Nanocomposites  F   Nanomagnetism Nanomaterials for Enery Computational Nanotechnology Commercialization of Nanotechnology The conference was represented by around 400 participants from several countries including delegates invited from USA, Germany, Japan, UK, Taiwan, Italy, Singapor...

Exploring the Immunotoxicity of Carbon Nanotubes

Directory of Open Access Journals (Sweden)

Yu Yanmei

2008-01-01

Full Text Available Abstract Mass production of carbon nanotubes (CNTs and their applications in nanomedicine lead to the increased exposure risk of nanomaterials to human beings. Although reports on toxicity of nanomaterials are rapidly growing, there is still a lack of knowledge on the potential toxicity of such materials to immune systems. This article reviews some existing studies assessing carbon nanotubes’ toxicity to immune system and provides the potential mechanistic explanation.

Nanomaterials in preventive dentistry

Science.gov (United States)

Hannig, Matthias; Hannig, Christian

2010-08-01

The prevention of tooth decay and the treatment of lesions and cavities are ongoing challenges in dentistry. In recent years, biomimetic approaches have been used to develop nanomaterials for inclusion in a variety of oral health-care products. Examples include liquids and pastes that contain nano-apatites for biofilm management at the tooth surface, and products that contain nanomaterials for the remineralization of early submicrometre-sized enamel lesions. However, the treatment of larger visible cavities with nanomaterials is still at the research stage. Here, we review progress in the development of nanomaterials for different applications in preventive dentistry and research, including clinical trials.

Functionalization of Carbon Nanomaterial Surface by Doxorubicin and Antibodies to Tumor Markers

Science.gov (United States)

Perepelytsina, Olena M.; Yakymchuk, Olena M.; Sydorenko, Mychailo V.; Bakalinska, Olga N.; Bloisi, Francesco; Vicari, Luciano Rosario Maria

2016-06-01

The actual task of oncology is effective treatment of cancer while causing a minimum harm to the patient. The appearance of polymer nanomaterials and technologies launched new applications and approaches of delivery and release of anticancer drugs. The goal of work was to test ultra dispersed diamonds (UDDs) and onion-like carbon (OLCs) as new vehicles for delivery of antitumor drug (doxorubicin (DOX)) and specific antibodies to tumor receptors. Stable compounds of UDDs and OLCs with DOX were obtained. As results of work, an effectiveness of functionalization was 2.94 % w/ w for OLC-DOX and 2.98 % w/ w for UDD-DOX. Also, there was demonstrated that UDD-DOX and OLC-DOX constructs had dose-dependent cytotoxic effect on tumor cells in the presence of trypsin. The survival of adenocarcinoma cells reduced from 52 to 28 % in case of incubation with the UDD-DOX in concentrations from 8.4-2.5 to 670-20 μg/ml and from 72 to 30 % after incubation with OLC-DOX. Simultaneously, antibodies to epidermal growth factor maintained 75 % of the functional activity and specificity after matrix-assisted pulsed laser evaporation deposition. Thus, the conclusion has been made about the prospects of selected new methods and approaches for creating an antitumor agent with capabilities targeted delivery of drugs.

Carbon Nanostructures for Tagging in Electrochemical Biosensing: A Review

Directory of Open Access Journals (Sweden)

Paloma Yáñez-Sedeño

2017-01-01

Full Text Available Growing demand for developing ultrasensitive electrochemical bioassays has led to the design of numerous signal amplification strategies. In this context, carbon-based nanomaterials have been demonstrated to be excellent tags for greatly amplifying the transduction of recognition events and simplifying the protocols used in electrochemical biosensing. This relevant role is due to the carbon-nanomaterials’ large surface area, excellent biological compatibility and ease functionalization and, in some cases, intrinsic electrochemistry. These carbon-based nanomaterials involve well-known carbon nanotubes (CNTs and graphene as well as the more recent use of other carbon nanoforms. This paper briefly discusses the advantages of using carbon nanostructures and their hybrid nanocomposites for amplification through tagging in electrochemical biosensing platforms and provides an updated overview of some selected examples making use of labels involving carbon nanomaterials, acting both as carriers for signal elements and as electrochemical tracers, applied to the electrochemical biosensing of relevant (biomarkers.

Recycling of rare earth magnet scraps: Carbon and oxygen removal from Nd magnet scraps

International Nuclear Information System (INIS)

Saguchi, A.; Asabe, K.; Fukuda, T.; Takahashi, W.; Suzuki, R.O.

2006-01-01

The decarburization and deoxidation technique for permanent Nd-Fe-B magnet scrap is investigated. The carbon and oxygen contamination damage the magnetic properties. The carbon content decreased less than 0.001% by heating in air. The two stage deoxidation is applied, iron oxides are reduced by heating in hydrogen thereafter rare earth oxides are removed by Ca-reduction and leaching. The appropriate conditions for deoxidation in the Ca-reduction and suppressing the re-oxidation in the leaching are investigated. The heating pattern in Ca-reduction and the leaching condition for the mixture composed of Ca compounds and Nd-Fe-B alloy powder greatly affects the oxygen content of recycled material. The decarburized and deoxidized Nd-Fe-B magnet scrap can be recycled as alloying elements by melting

Characterization of nanomaterials

International Nuclear Information System (INIS)

Montone, Amelia; Aurora, Annalisa; Di Girolamo, Giovanni

2015-01-01

This paper provides an overview of the main techniques used for the characterization of nanomaterials. The knowledge of some basic characteristics, inherent morphology, microstructure, the distribution phase and chemical composition, it is essential to evaluate the functional properties of nanomaterials and make predictions about their behavior in operation. For the characterization of nanomaterials can be used in both imaging techniques both analytic techniques. Among the first found wide application optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Among the latter some types of spectroscopy and X-ray diffraction (XRD). For each type of material to characterize the choice of the most appropriate technique it is based on the type of details that you want to obtain, and on their scale. In this paper are discussed in detail some examples and the main methods used for the characterization of nanomaterials. [it

A decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping).

Science.gov (United States)

Arts, Josje H E; Hadi, Mackenzie; Irfan, Muhammad-Adeel; Keene, Athena M; Kreiling, Reinhard; Lyon, Delina; Maier, Monika; Michel, Karin; Petry, Thomas; Sauer, Ursula G; Warheit, David; Wiench, Karin; Wohlleben, Wendel; Landsiedel, Robert

2015-03-15

The European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) 'Nano Task Force' proposes a Decision-making framework for the grouping and testing of nanomaterials (DF4nanoGrouping) that consists of 3 tiers to assign nanomaterials to 4 main groups, to perform sub-grouping within the main groups and to determine and refine specific information needs. The DF4nanoGrouping covers all relevant aspects of a nanomaterial's life cycle and biological pathways, i.e. intrinsic material and system-dependent properties, biopersistence, uptake and biodistribution, cellular and apical toxic effects. Use (including manufacture), release and route of exposure are applied as 'qualifiers' within the DF4nanoGrouping to determine if, e.g. nanomaterials cannot be released from a product matrix, which may justify the waiving of testing. The four main groups encompass (1) soluble nanomaterials, (2) biopersistent high aspect ratio nanomaterials, (3) passive nanomaterials, and (4) active nanomaterials. The DF4nanoGrouping aims to group nanomaterials by their specific mode-of-action that results in an apical toxic effect. This is eventually directed by a nanomaterial's intrinsic properties. However, since the exact correlation of intrinsic material properties and apical toxic effect is not yet established, the DF4nanoGrouping uses the 'functionality' of nanomaterials for grouping rather than relying on intrinsic material properties alone. Such functionalities include system-dependent material properties (such as dissolution rate in biologically relevant media), bio-physical interactions, in vitro effects and release and exposure. The DF4nanoGrouping is a hazard and risk assessment tool that applies modern toxicology and contributes to the sustainable development of nanotechnological products. It ensures that no studies are performed that do not provide crucial data and therefore saves animals and resources. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights

The classification and labeling of nanomaterials according to Regulation 1272/2008 (CLP)

International Nuclear Information System (INIS)

Alessandrelli, Maria; Di Prospero Fanghella, Paola; Polci, Maria Letizia

2015-01-01

From a regulatory standpoint for nanomaterials it may take parameters and specific information requirements can describe their properties. Regulation (EC) No. 1272/2008 (CLP) is closely linked to Regulation (EC) No. 1907/2006 (REACH, which stands for Registration, Evaluation, Authorisation and Restriction of Chemicals), directly applicable to suppliers who manufacture, import, use or distribute chemical substances and mixtures and which aims to ensure the free movement of substances, mixtures and articles always in accordance with a high level of human health and the environment. REACH and CLP cover substances, in any size, shape or physical state, but does not include any specific definition or provision relating to nanomaterials. The moment when a substance is produced or marketed in the form of nanomaterials, the registration dossier needs to be updated to include the different classification and labeling of the substance in the nano form. [it

Plasma processing of nanomaterials

CERN Document Server

Sankaran, R Mohan

2014-01-01

CRC Press author R. Mohan Sankaran is the winner of the 2011 Peter Mark Memorial Award "… for the development of a tandem plasma synthesis method to grow carbon nanotubes with unprecedented control over the nanotube properties and chirality." -2011 AVS Awards Committee"Readers who want to learn about how nanomaterials are processed, using the most recent methods, will benefit greatly from this book. It contains very recent technical details on plasma processing and synthesis methods used by current researchers developing new nano-based materials, with all the major plasma-based processing techniques used today being thoroughly discussed."-John J. Shea, IEEE Electrical Insulation Magazine, May/June 2013, Vol. 29, No. 3.

The Application of Carbon Nanotubes in Magnetic Fluid Hyperthermia

Directory of Open Access Journals (Sweden)

Grzegorz Raniszewski

2015-01-01

Full Text Available The aim of this paper is to present the results of the investigation into the applications of carbon nanotubes with ferromagnetic nanoparticles as nanoheaters for targeted thermal ablation of cancer cells. Relevant nanoparticles’ characteristics were exploited in terms of their functionality for biomedical applications and their magnetic properties were examined to determine heat generation efficiency induced by the exposure of the particles to an alternating magnetic field. The influence of the electromagnetic field on the human body tissues was assessed, providing quantitative measures of the interaction. The behavior of a liquid containing magnetic particles, during the exposure to the alternating magnetic field, was verified. As for the application for the ferromagnetic carbon nanotubes, the authors investigated temperature distribution in human liver tumor together with Arrhenius tissue damage model and the thermal dose concept.

A solution phase fabrication of magnetic nanoparticles encapsulated in carbon

International Nuclear Information System (INIS)

Wei Xianwen; Zhu Guoxing; Xia Chuanjun; Ye Yin

2006-01-01

To avoid high energy consumption, intensive use of hardware and high cost in the manufacture of nanoparticles encapsulated in carbon, a simple, efficient and economical solution-phase method for the fabrication of FeNi at C nanostructures has been explored. The reaction to the magnetic metal at C structures here is conducted at a relatively low temperature (160 deg. C) and this strategy can be transferred to prepare other transition metal at C core-shell nanostructures. The saturation magnetization of metal in metal at C nanostructures is similar to those of the corresponding buck metals. Magnetic metal at C nanostructures with magnetic metal nanoparticles inside and a functionalized carbon surface outside may not only provide the opportunity to tailor the magnetic properties for magnetic storage devices and therapeutics but also make possible the loading of other functional molecules (e.g. enzymes, antigens) for clinic diagnostics, molecular biology, bioengineering, and catalysis

Submerged Glow-Discharge Plasma: An Economical Approach to Convert Construction Scrap Metal into Nanomaterials

Directory of Open Access Journals (Sweden)

Yek Peter Nai Yuh

2018-01-01

Full Text Available Submerged glow-discharge plasma (SGDP is relatively new among the various methods available for nanomaterials synthesis (NMs techniques. This method allows great control over the production cost of nanomaterials synthesis. A lab-scale batch type SDGP technology has been constructed to produce nanomaterials and investigate the inter-relationship between plasma excitation voltages, electrodes submerged areas and electrolyte concentration. Metal oxide nanospheres has been synthesised from different electrolyte concentrations (1M-0.001M and characterized by Scanning Electron Microscopy (SEM and Energy Dispersive Spectroscopy (EDS. As the major results showed that the nanospheres are uniformly spherical with diameter size distribution are between 100 nm - 2μm. EDS analysis shown the nano-Iron Oxide have been formed. Scrap metal initially showed around 6.45% and 93.55% of Carbon and Iron composition respectively. After SGDP process to the scrap metal, Carbon content has increased to 34-35% and Iron content has reduced to around 15-40%. EDS results also shown the higher percentage of Iron amount has remained with lower electrolyte concentration and Current is proportionally related to submersion area of cathode.

Shape-dependent plasma-catalytic activity of ZnO nanomaterials coated on porous ceramic membrane for oxidation of butane.

Science.gov (United States)

Sanjeeva Gandhi, M; Mok, Young Sun

2014-12-01

In order to explore the effects of the shape of ZnO nanomaterials on the plasma-catalytic decomposition of butane and the distribution of byproducts, three types of ZnO nanomaterials (nanoparticles (NPs), nanorods (NRs) and nanowires (NWs)) were prepared and coated on multi-channel porous alumina ceramic membrane. The structures and morphologies of the nanomaterials were confirmed by X-ray diffraction method and scanning electron microscopy. The observed catalytic activity of ZnO in the oxidative decomposition of butane was strongly shape-dependent. It was found that the ZnO NWs exhibited higher catalytic activity than the other nanomaterials and could completely oxidize butane into carbon oxides (COx). When using the bare or ZnO NPs-coated ceramic membrane, several unwanted partial oxidation and decomposition products like acetaldehyde, acetylene, methane and propane were identified during the decomposition of butane. When the ZnO NWs- or ZnO NRs-coated membrane was used, however, the formation of such unwanted byproducts except methane was completely avoided, and full conversion into COx was achieved. Better carbon balance and COx selectivity were obtained with the ZnO NWs and NRs than with the NPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nanomaterials-based enzyme electrochemical biosensors operating through inhibition for biosensing applications.

Science.gov (United States)

Kurbanoglu, Sevinc; Ozkan, Sibel A; Merkoçi, Arben

2017-03-15

In recent years great progress has been made in applying nanomaterials to design novel biosensors. Use of nanomaterials offers to biosensing platforms exceptional optical, electronic and magnetic properties. Nanomaterials can increase the surface of the transducing area of the sensors that in turn bring an increase in catalytic behaviors. They have large surface-to-volume ratio, controlled morphology and structure that also favor miniaturization, an interesting advantage when the sample volume is a critical issue. Biosensors have great potential for achieving detect-to-protect devices: devices that can be used in detections of pollutants and other treating compounds/analytes (drugs) protecting citizens' life. After a long term focused scientific and financial efforts/supports biosensors are expected now to fulfill their promise such as being able to perform sampling and analysis of complex samples with interest for clinical or environment fields. Among all types of biosensors, enzymatic biosensors, the most explored biosensing devices, have an interesting property, the inherent inhibition phenomena given the enzyme-substrate complex formation. The exploration of such phenomena is making remarkably important their application as research and applied tools in diagnostics. Different inhibition biosensor systems based on nanomaterials modification has been proposed and applied. The role of nanomaterials in inhibition-based biosensors for the analyses of different groups of drugs as well as contaminants such as pesticides, phenolic compounds and others, are discussed in this review. This deep analysis of inhibition-based biosensors that employ nanomaterials will serve researchers as a guideline for further improvements and approaching of these devices to real sample applications so as to reach society needs and such biosensor market demands. Copyright © 2016 Elsevier B.V. All rights reserved.

Dispersion of Nanomaterials in Aqueous Media: Towards Protocol Optimization.

Science.gov (United States)

Kaur, Inder; Ellis, Laura-Jayne; Romer, Isabella; Tantra, Ratna; Carriere, Marie; Allard, Soline; Mayne-L'Hermite, Martine; Minelli, Caterina; Unger, Wolfgang; Potthoff, Annegret; Rades, Steffi; Valsami-Jones, Eugenia

2017-12-25

The sonication process is commonly used for de-agglomerating and dispersing nanomaterials in aqueous based media, necessary to improve homogeneity and stability of the suspension. In this study, a systematic step-wise approach is carried out to identify optimal sonication conditions in order to achieve a stable dispersion. This approach has been adopted and shown to be suitable for several nanomaterials (cerium oxide, zinc oxide, and carbon nanotubes) dispersed in deionized (DI) water. However, with any change in either the nanomaterial type or dispersing medium, there needs to be optimization of the basic protocol by adjusting various factors such as sonication time, power, and sonicator type as well as temperature rise during the process. The approach records the dispersion process in detail. This is necessary to identify the time points as well as other above-mentioned conditions during the sonication process in which there may be undesirable changes, such as damage to the particle surface thus affecting surface properties. Our goal is to offer a harmonized approach that can control the quality of the final, produced dispersion. Such a guideline is instrumental in ensuring dispersion quality repeatability in the nanoscience community, particularly in the field of nanotoxicology.

Fast adsorption kinetics of highly dispersed ultrafine nickel/carbon nanoparticles for organic dye removal

Science.gov (United States)

Kim, Taek-Seung; Song, Hee Jo; Dar, Mushtaq Ahmad; Lee, Hack-Jun; Kim, Dong-Wan

2018-05-01

Magnetic metal/carbon nano-materials are attractive for pollutant adsorption and removal. In this study, ultrafine nickel/carbon nanoparticles are successfully prepared via electrical wire explosion processing in ethanol media for the elimination of pollutant organic dyes such as Rhodamine B and methylene blue in aqueous solutions. High specific surface areas originating from both the nano-sized particles and the existence of carbon on the surface of Ni nanoparticles enhance dye adsorption capacity. In addition to this, the excellent dispersity of Ni/C nanoparticles in aqueous dye solutions leads to superior adsorption rates. The adsorption kinetics for the removal of organic dyes by Ni/C nanoparticles agree with a pseudo-second-order model and follow Freundlich adsorption isotherm behavior.

Biophysical Influence of Airborne Carbon Nanomaterials on Natural Pulmonary Surfactant

OpenAIRE

Valle, Russell P.; Wu, Tony; Zuo, Yi Y.

2015-01-01

Inhalation of nanoparticles (NP), including lightweight airborne carbonaceous nanomaterials (CNM), poses a direct and systemic health threat to those who handle them. Inhaled NP penetrate deep pulmonary structures in which they first interact with the pulmonary surfactant (PS) lining at the alveolar air–water interface. In spite of many research efforts, there is a gap of knowledge between in vitro biophysical study and in vivo inhalation toxicology since all existing biophysical models handl...

Assessment of soil organic carbon stocks under future climate and land cover changes in Europe.

Science.gov (United States)

Yigini, Yusuf; Panagos, Panos

2016-07-01

Soil organic carbon plays an important role in the carbon cycling of terrestrial ecosystems, variations in soil organic carbon stocks are very important for the ecosystem. In this study, a geostatistical model was used for predicting current and future soil organic carbon (SOC) stocks in Europe. The first phase of the study predicts current soil organic carbon content by using stepwise multiple linear regression and ordinary kriging and the second phase of the study projects the soil organic carbon to the near future (2050) by using a set of environmental predictors. We demonstrate here an approach to predict present and future soil organic carbon stocks by using climate, land cover, terrain and soil data and their projections. The covariates were selected for their role in the carbon cycle and their availability for the future model. The regression-kriging as a base model is predicting current SOC stocks in Europe by using a set of covariates and dense SOC measurements coming from LUCAS Soil Database. The base model delivers coefficients for each of the covariates to the future model. The overall model produced soil organic carbon maps which reflect the present and the future predictions (2050) based on climate and land cover projections. The data of the present climate conditions (long-term average (1950-2000)) and the future projections for 2050 were obtained from WorldClim data portal. The future climate projections are the recent climate projections mentioned in the Fifth Assessment IPCC report. These projections were extracted from the global climate models (GCMs) for four representative concentration pathways (RCPs). The results suggest an overall increase in SOC stocks by 2050 in Europe (EU26) under all climate and land cover scenarios, but the extent of the increase varies between the climate model and emissions scenarios. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Photo-Responsive Graphene and Carbon Nanotubes to Control and Tackle Biological Systems

Science.gov (United States)

Cardano, Francesca; Frasconi, Marco; Giordani, Silvia

2018-04-01

Photo-responsive multifunctional nanomaterials are receiving considerable attention for biological applications because of their unique properties. The functionalization of the surface of carbon nanotubes (CNTs) and graphene, among other carbon based nanomaterials, with molecular switches that exhibit reversible transformations between two or more isomers in response to different kind of external stimuli, such as electromagnetic radiation, temperature and pH, has allowed the control of the optical and electrical properties of the nanomaterial. Light-controlled molecular switches, such as azobenzene and spiropyran, have attracted a lot of attention for nanomaterial’s functionalization because of the remote modulation of their physicochemical properties using light stimulus. The enhanced properties of the hybrid materials obtained from the coupling of carbon based nanomaterials with light-responsive switches has enabled the fabrication of smart devices for various biological applications, including drug delivery, bioimaging and nanobiosensors. In this review, we highlight the properties of photo-responsive carbon nanomaterials obtained by the conjugation of CNTs and graphene with azobenzenes and spiropyrans molecules to investigate biological systems, devising possible future directions in the field.

Magnetic susceptibility of molecular carbon: nanotubes and fullerite

Energy Technology Data Exchange (ETDEWEB)

Ramirez, A P; Haddon, R C; Zhou, O; Fleming, R M; Zhang, J; McClure, S M; Smalley, R E [AT T Bell Laboratories, Murray Hill, NJ (United States)

1994-07-01

Elemental carbon can be synthesized in a variety of geometrical forms, from three-dimensional extended structures (diamond) to finite molecules (C[sub 60] fullerite). Results are presented here on the magnetic susceptibility of the least well-understood members of this family, nanotubes and C[sub 60] fullerite. (1) Nanotubes represent the cylindrical form of carbon, intermediate between graphite and fullerite. They are found to have significantly larger orientation-averaged susceptibility, on a per carbon basis, than any other form of elemental carbon. This susceptibility implies an average band structure among nanotubes similar to that of graphite. (2) High-resolution magnetic susceptibility data on C[sub 60] fullerite near the molecular orientational-ordering transition at 259 K show a sharp jump corresponding to 2.5 centimeter-gram-second parts per million per mole of C[sub 60]. This jump directly demonstrates the effect of an intermolecular cooperative transition on an intramolecular electronic property, where the susceptibility jump may be ascribed to a change in the shape of the molecule due to lattice forces.

Relative risk analysis of several manufactured nanomaterials: an insurance industry context.

Science.gov (United States)

Robichaud, Christine Ogilvie; Tanzil, Dicksen; Weilenmann, Ulrich; Wiesner, Mark R

2005-11-15

A relative risk assessment is presented for the industrial fabrication of several nanomaterials. The production processes for five nanomaterials were selected for this analysis, based on their current or near-term potential for large-scale production and commercialization: single-walled carbon nanotubes, bucky balls (C60), one variety of quantum dots, alumoxane nanoparticles, and nano-titanium dioxide. The assessment focused on the activities surrounding the fabrication of nanomaterials, exclusive of any impacts or risks with the nanomaterials themselves. A representative synthesis method was selected for each nanomaterial based on its potential for scaleup. A list of input materials, output materials, and waste streams for each step of fabrication was developed and entered into a database that included key process characteristics such as temperature and pressure. The physical-chemical properties and quantities of the inventoried materials were used to assess relative risk based on factors such as volatility, carcinogenicity, flammability, toxicity, and persistence. These factors were first used to qualitatively rank risk, then combined using an actuarial protocol developed by the insurance industry for the purpose of calculating insurance premiums for chemical manufacturers. This protocol ranks three categories of risk relative to a 100 point scale (where 100 represents maximum risk): incident risk, normal operations risk, and latent contamination risk. Results from this analysis determined that relative environmental risk from manufacturing each of these five materials was comparatively low in relation to other common industrial manufacturing processes.

Nanostructure investigation of magnetic nanomaterial Ni0.5Zn0.3Cu0.2Fe2O4 synthesized by sol-gel method

International Nuclear Information System (INIS)

Pransisco, Prengki; Shafie, Afza; Guan, Beh Hoe

2015-01-01

Magnetic nanomaterial Ni 0.5 Zn 0.3 Cu 0.2 Fe 2 O 4 was successfully prepared by using sol-gel method. Heat treatment on material is always giving defect on properties of material. This paper investigates the effect of heat treatment on nanostructure of magnetic nanomaterial Ni 0.5 Zn 0.3 Cu 0.2 Fe 2 O 4 . According to thermo gravimetric analysis (TGA) that after 600°C there is no more weight loss detected and it was decided as minimum calcination temperature. Intensity, crystallite size, structure, lattice parameter and d-spacing of the material were investigated by using X-ray diffraction (XRD). High resolution transmission electron microscope (HRTEM) was used to examine nanostructure, nanosize, shape and distribution particle of magnetic material Ni 0.5 Zn 0.3 Cu 0.2 Fe 2 O 4 and variable pressure field emission scanning electron microscope (VP-FESEM) was used to investigate the surface morphology and topography of the material. The XRD result shows single-phase cubic spinel structure with average crystallite size in the range of 25.6-95.9 nm, the value of the intensity of the material was increased with increasing temperature, and followed by lattice parameter was increased with increasing calcination temperature, value of d-spacing was relatively decreased with accompanied increasing temperature. From HRTEM result the distribution of particles was tend to be agglomerates with particle size of 7.8-17.68 nm. VP-FESEM result shows that grain size of the material increases with increasing calcination temperature and the surface morphology shows that the material is in hexagonal shape and it was also proved by mapping result which showing the presence each of constituents inside the compound

Nanomaterial categorization for assessing risk potential to facilitate regulatory decision-making.

Science.gov (United States)

Godwin, Hilary; Nameth, Catherine; Avery, David; Bergeson, Lynn L; Bernard, Daniel; Beryt, Elizabeth; Boyes, William; Brown, Scott; Clippinger, Amy J; Cohen, Yoram; Doa, Maria; Hendren, Christine Ogilvie; Holden, Patricia; Houck, Keith; Kane, Agnes B; Klaessig, Frederick; Kodas, Toivo; Landsiedel, Robert; Lynch, Iseult; Malloy, Timothy; Miller, Mary Beth; Muller, Julie; Oberdorster, Gunter; Petersen, Elijah J; Pleus, Richard C; Sayre, Philip; Stone, Vicki; Sullivan, Kristie M; Tentschert, Jutta; Wallis, Philip; Nel, Andre E

2015-01-01

For nanotechnology to meet its potential as a game-changing and sustainable technology, it is important to ensure that the engineered nanomaterials and nanoenabled products that gain entry to the marketplace are safe and effective. Tools and methods are needed for regulatory purposes to allow rapid material categorization according to human health and environmental risk potential, so that materials of high concern can be targeted for additional scrutiny, while material categories that pose the least risk can receive expedited review. Using carbon nanotubes as an example, we discuss how data from alternative testing strategies can be used to facilitate engineered nanomaterial categorization according to risk potential and how such an approach could facilitate regulatory decision-making in the future.

Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

KAUST Repository

Fidiani, Elok; Da Costa, Pedro M. F. J.; Wolter, Anja U. B.; Maier, Diana; Buechner, Bernd; Hampel, Silke

2013-01-01

Gd-filled carbon nanotubes (which include the so-called gadonanotubes(1)) have been attracting much interest due to their potential use in medical diagnostic applications. In the present work, a vacuum filling method was performed to confine gadolinium(III) iodide in carbon nanotubes (CNTs). Filling yields in excess of 50% were obtained. Cleaning and dosing of the external walls was undertaken, as well as the study of the filled CNT magnetic properties. Overall, we found that the encapsulating procedure can lead to reduction of the lanthanide metal and induce disorder in the initial GdI3-type structure. Notwithstanding, the magnetic response of the material is not compromised, retaining a strong paramagnetic response and an effective magnetic moment of similar to 6 mu B. Our results may entice further investigation into whether an analogous Gd3+ to Gd2+ reduction takes place in other Gd-filled CNT systems.

Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

KAUST Repository

Fidiani, Elok

2013-08-15

Gd-filled carbon nanotubes (which include the so-called gadonanotubes(1)) have been attracting much interest due to their potential use in medical diagnostic applications. In the present work, a vacuum filling method was performed to confine gadolinium(III) iodide in carbon nanotubes (CNTs). Filling yields in excess of 50% were obtained. Cleaning and dosing of the external walls was undertaken, as well as the study of the filled CNT magnetic properties. Overall, we found that the encapsulating procedure can lead to reduction of the lanthanide metal and induce disorder in the initial GdI3-type structure. Notwithstanding, the magnetic response of the material is not compromised, retaining a strong paramagnetic response and an effective magnetic moment of similar to 6 mu B. Our results may entice further investigation into whether an analogous Gd3+ to Gd2+ reduction takes place in other Gd-filled CNT systems.

Carbon Nanotropes: A Contemporary Paradigm in Drug Delivery

Directory of Open Access Journals (Sweden)

Avinash C. Tripathi

2015-05-01

Full Text Available Discovery of fullerenes and other nanosized carbon allotropes has opened a vast new field of possibilities in nanotechnology and has become one of the most promising research areas. Carbon nanomaterials have drawn interest as carriers of biologically pertinent molecules due to their distinctive physical, chemical and physiological properties. We have assigned the nomenclature “Carbon Nanotropes” to the nanosized carbon allotropes. Carbon nanotropes such as fullerenes, carbon nanotubes (CNTs and graphenes, have exhibited wide applicability in drug delivery, owing to their small size and biological activity. The nanotherapeutics/diagnostics will allow a deeper understanding of human ills including cancer, neurodegenerative diseases, genetic disorders and various other complications. Recently, nanomaterials with multiple functions, such as drug carrier, MRI, optical imaging, photothermal therapy, etc., have become more and more popular in the domain of cancer and other areas of research. This review is an endeavor to bring together the usefulness of the carbon nanomaterials in the field of drug delivery. The last section of the review encompasses the recent patents granted on carbon nanotropes at United State Patent Trademark Office (USPTO in the related field.

Application of an activated carbon-based support for magnetic solid phase extraction followed by spectrophotometric determination of tartrazine in commercial beverages.

Science.gov (United States)

Rodríguez, José A; Escamilla-Lara, Karen A; Guevara-Lara, Alfredo; Miranda, Jose M; Páez-Hernández, Ma Elena

2015-01-01

A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L(-1), with a limit of detection of 1 mg L(-1). The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P < 0.05).

Dysprosium Acetylacetonato Single-Molecule Magnet Encapsulated in Carbon Nanotubes

Directory of Open Access Journals (Sweden)

Ryo Nakanishi

2016-12-01

Full Text Available Dy single-molecule magnets (SMMs, which have several potential uses in a variety of applications, such as quantum computing, were encapsulated in multi-walled carbon nanotubes (MWCNTs by using a capillary method. Encapsulation was confirmed by using transmission electron microscopy (TEM. In alternating current magnetic measurements, the magnetic susceptibilities of the Dy acetylacetonato complexes showed clear frequency dependence even inside the MWCNTs, meaning that this hybrid can be used as magnetic materials in devices.

Plasma nanofabrication and nanomaterials safety

International Nuclear Information System (INIS)

Han, Z J; Levchenko, I; Kumar, S; Yajadda, M M A; Yick, S; Seo, D H; Martin, P J; Ostrikov, K; Peel, S; Kuncic, Z

2011-01-01

The fast advances in nanotechnology have raised increasing concerns related to the safety of nanomaterials when exposed to humans, animals and the environment. However, despite several years of research, the nanomaterials safety field is still in its infancy owing to the complexities of structural and surface properties of these nanomaterials and organism-specific responses to them. Recently, plasma-based technology has been demonstrated as a versatile and effective way for nanofabrication, yet its health and environment-benign nature has not been widely recognized. Here we address the environmental and occupational health and safety effects of various zero- and one-dimensional nanomaterials and elaborate the advantages of using plasmas as a safe nanofabrication tool. These advantages include but are not limited to the production of substrate-bound nanomaterials, the isolation of humans from harmful nanomaterials, and the effective reforming of toxic and flammable gases. It is concluded that plasma nanofabrication can minimize the hazards in the workplace and represents a safe way for future nanofabrication technologies.

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

Directory of Open Access Journals (Sweden)

Stephen Hill

2017-04-01

Full Text Available Fluorescent carbon dots (FCDs are an emerging class of nanomaterials made from carbon sources that have been hailed as potential non-toxic replacements to traditional semiconductor quantum dots (QDs. Particularly in the areas of live imaging and drug delivery, due to their water solubility, low toxicity and photo- and chemical stability. Carbohydrates are readily available chiral biomolecules in nature which offer an attractive and cheap starting material from which to synthesise FCDs with distinct features and interesting applications. This mini-review article will cover the progress in the development of FCDs prepared from carbohydrate sources with an emphasis on their synthesis, functionalization and technical applications, including discussions on current challenges.

Modeling of nanotoxicity molecular interactions of nanomaterials with bionanomachines

CERN Document Server

Zhou, Ruhong

2015-01-01

This book provides a comprehensive overview of the fundamentals of nanotoxicity modeling and its implications for the development of novel nanomedicines. It lays out the fundamentals of nanotoxicity modeling for an array of nanomaterial systems, ranging from carbon-based nanoparticles to noble metals, metal oxides, and quantum dots. The author illustrates how molecular (classical mechanics) and atomic (quantum mechanics) modeling approaches can be applied to bolster our understanding of many important aspects of this critical nanotoxicity issue. Each chapter is organized by types of nanomaterials for practicality, making this an ideal book for senior undergraduate students, graduate students, and researchers in nanotechnology, chemistry, physics, molecular biology, and computer science. It is also of interest to academic and industry professionals who work on nanodrug delivery and related biomedical applications, and aids readers in their biocompatibility assessment efforts in the coming age of nanotechnology...

Magnetic carbon nanotubes: preparation, physical properties, and applications in biomedicine.

Science.gov (United States)

Samadishadlou, Mehrdad; Farshbaf, Masoud; Annabi, Nasim; Kavetskyy, Taras; Khalilov, Rovshan; Saghfi, Siamak; Akbarzadeh, Abolfazl; Mousavi, Sepideh

2017-10-18

Magnetic carbon nanotubes (MCNTs) have been widely studied for their potential applications in medicine, diagnosis, cell biology, analytical chemistry, and environmental technology. Introduction of MCNTs paved the way for the emergence of new approaches in nanobiotechnology and biomedicine as a result of their multifarious properties embedded within either the carbon nanotubes (CNTs) or magnetic parts. Numerous preparation techniques exists for functionalizing CNTs with magnetic nanoparticles, and these versatile strategies lay the ground for the generation of novel and versatile systems which are applicable to many industries and biological areas. Here, we review and discuss the recent papers dealing with MCNTs and their application in biomedical and industrial fields.

Engineering the heart: Evaluation of conductive nanomaterials for improving implant integration and cardiac function

Science.gov (United States)

Zhou, Jin; Chen, Jun; Sun, Hongyu; Qiu, Xiaozhong; Mou, Yongchao; Liu, Zhiqiang; Zhao, Yuwei; Li, Xia; Han, Yao; Duan, Cuimi; Tang, Rongyu; Wang, Chunlan; Zhong, Wen; Liu, Jie; Luo, Ying; (Mengqiu) Xing, Malcolm; Wang, Changyong

2014-01-01

Recently, carbon nanotubes together with other types of conductive materials have been used to enhance the viability and function of cardiomyocytes in vitro. Here we demonstrated a paradigm to construct ECTs for cardiac repair using conductive nanomaterials. Single walled carbon nanotubes (SWNTs) were incorporated into gelatin hydrogel scaffolds to construct three-dimensional ECTs. We found that SWNTs could provide cellular microenvironment in vitro favorable for cardiac contraction and the expression of electrochemical associated proteins. Upon implantation into the infarct hearts in rats, ECTs structurally integrated with the host myocardium, with different types of cells observed to mutually invade into implants and host tissues. The functional measurements showed that SWNTs were essential to improve the performance of ECTs in inhibiting pathological deterioration of myocardium. This work suggested that conductive nanomaterials hold therapeutic potential in engineering cardiac tissues to repair myocardial infarction. PMID:24429673

Biodegradation of Carbon Nanotubes, Graphene, and Their Derivatives.

Science.gov (United States)

Chen, Ming; Qin, Xiaosheng; Zeng, Guangming

2017-09-01

Carbon nanotubes (CNTs), graphene (GRA), and their derivatives are promising materials for a wide range of applications such as pollutant removal, enzyme immobilization, bioimaging, biosensors, and drug delivery and are rapidly increasing in use and increasingly mass produced. The biodegradation of carbon nanomaterials by microbes and enzymes is now of great importance for both reducing their toxicity to living organisms and removing them from the environment. Here we review recent progress in the biodegradation field from the point of view of the primary microbes and enzymes that can degrade these nanomaterials, along with experimental and molecular simulation methods for the exploration of nanomaterial degradation. Further efforts should primarily aim toward expanding the repertoire of microbes and enzymes and exploring optimal conditions for the degradation of nanomaterials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Land-cover effects on soil organic carbon stocks in a European city.

Science.gov (United States)

Edmondson, Jill L; Davies, Zoe G; McCormack, Sarah A; Gaston, Kevin J; Leake, Jonathan R

2014-02-15

Soil is the vital foundation of terrestrial ecosystems storing water, nutrients, and almost three-quarters of the organic carbon stocks of the Earth's biomes. Soil organic carbon (SOC) stocks vary with land-cover and land-use change, with significant losses occurring through disturbance and cultivation. Although urbanisation is a growing contributor to land-use change globally, the effects of urban land-cover types on SOC stocks have not been studied for densely built cities. Additionally, there is a need to resolve the direction and extent to which greenspace management such as tree planting impacts on SOC concentrations. Here, we analyse the effect of land-cover (herbaceous, shrub or tree cover), on SOC stocks in domestic gardens and non-domestic greenspaces across a typical mid-sized U.K. city (Leicester, 73 km(2), 56% greenspace), and map citywide distribution of this ecosystem service. SOC was measured in topsoil and compared to surrounding extra-urban agricultural land. Average SOC storage in the city's greenspace was 9.9 kg m(-2), to 21 cm depth. SOC concentrations under trees and shrubs in domestic gardens were greater than all other land-covers, with total median storage of 13.5 kg m(-2) to 21 cm depth, more than 3 kg m(-2) greater than any other land-cover class in domestic and non-domestic greenspace and 5 kg m(-2) greater than in arable land. Land-cover did not significantly affect SOC concentrations in non-domestic greenspace, but values beneath trees were higher than under both pasture and arable land, whereas concentrations under shrub and herbaceous land-covers were only higher than arable fields. We conclude that although differences in greenspace management affect SOC stocks, trees only marginally increase these stocks in non-domestic greenspaces, but may enhance them in domestic gardens, and greenspace topsoils hold substantial SOC stores that require protection from further expansion of artificial surfaces e.g. patios and driveways. Copyright �

Induced Magnetic Moment in Defected Single-Walled Carbon Nanotubes

International Nuclear Information System (INIS)

Liu Hong

2006-01-01

The existence of a large induced magnetic moment in defect single-walled carbon nanotube(SWNT) is predicted using the Green's function method. Specific to this magnetic moment of defect SWNT is its magnitude which is several orders of magnitude larger than that of perfect SWNT. The induced magnetic moment also shows certain remarkable features. Therefore, we suggest that two pair-defect orientations in SWNT can be distinguished in experiment through the direction of the induced magnetic moment at some Specific energy points

Magnetism as indirect tool for carbon content assessment in nickel nanoparticles

Science.gov (United States)

Oumellal, Y.; Magnin, Y.; Martínez de Yuso, A.; Aguiar Hualde, J. M.; Amara, H.; Paul-Boncour, V.; Matei Ghimbeu, C.; Malouche, A.; Bichara, C.; Pellenq, R.; Zlotea, C.

2017-12-01

We report a combined experimental and theoretical study to ascertain carbon solubility in nickel nanoparticles embedded into a carbon matrix via the one-pot method. This original approach is based on the experimental characterization of the magnetic properties of Ni at room temperature and Monte Carlo simulations used to calculate the magnetization as a function of C content in Ni nanoparticles. Other commonly used experimental methods fail to accurately determine the chemical analysis of these types of nanoparticles. Thus, we could assess the C content within Ni nanoparticles and it decreases from 8 to around 4 at. % with increasing temperature during the synthesis. This behavior could be related to the catalytic transformation of dissolved C in the Ni particles into graphite layers surrounding the particles at high temperature. The proposed approach is original and easy to implement experimentally since only magnetization measurements at room temperature are needed. Moreover, it can be extended to other types of magnetic nanoparticles dissolving carbon.

In vitro assessments of nanomaterial toxicity.

Science.gov (United States)

Jones, Clinton F; Grainger, David W

2009-06-21

Nanotechnology has grown from a scientific interest to a major industry with both commodity and specialty nanomaterial exposure to global populations and ecosystems. Sub-micron materials are currently used in a wide variety of consumer products and in clinical trials as drug delivery carriers and imaging agents. Due to the expected growth in this field and the increasing public exposure to nanomaterials, both from intentional administration and inadvertent contact, improved characterization and reliable toxicity screening tools are required for new and existing nanomaterials. This review discusses current methodologies used to assess nanomaterial physicochemical properties and their in vitro effects. Current methods lack the desired sensitivity, reliability, correlation and sophistication to provide more than limited, often equivocal, pieces of the overall nanomaterial performance parameter space, particularly in realistic physiological or environmental models containing cells, proteins and solutes. Therefore, improved physicochemical nanomaterial assays are needed to provide accurate exposure risk assessments and genuine predictions of in vivo behavior and therapeutic value. Simpler model nanomaterial systems in buffer do not accurately duplicate this complexity or predict in vivo behavior. A diverse portfolio of complementary material characterization tools and bioassays are required to validate nanomaterial properties in physiology.

Design of Nanomaterial Synthesis by Aerosol Processes

Science.gov (United States)

Buesser, Beat; Pratsinis, Sotiris E.

2013-01-01

Aerosol synthesis of materials is a vibrant field of particle technology and chemical reaction engineering. Examples include the manufacture of carbon blacks, fumed SiO2, pigmentary TiO2, ZnO vulcanizing catalysts, filamentary Ni, and optical fibers, materials that impact transportation, construction, pharmaceuticals, energy, and communications. Parallel to this, development of novel, scalable aerosol processes has enabled synthesis of new functional nanomaterials (e.g., catalysts, biomaterials, electroceramics) and devices (e.g., gas sensors). This review provides an access point for engineers to the multiscale design of aerosol reactors for the synthesis of nanomaterials using continuum, mesoscale, molecular dynamics, and quantum mechanics models spanning 10 and 15 orders of magnitude in length and time, respectively. Key design features are the rapid chemistry; the high particle concentrations but low volume fractions; the attainment of a self-preserving particle size distribution by coagulation; the ratio of the characteristic times of coagulation and sintering, which controls the extent of particle aggregation; and the narrowing of the aggregate primary particle size distribution by sintering. PMID:22468598

MOF-Derived ZnO Nanoparticles Covered by N-Doped Carbon Layers and Hybridized on Carbon Nanotubes for Lithium-Ion Battery Anodes.

Science.gov (United States)

Zhang, Hui; Wang, Yunsong; Zhao, Wenqi; Zou, Mingchu; Chen, Yijun; Yang, Liusi; Xu, Lu; Wu, Huaisheng; Cao, Anyuan

2017-11-01

Metal-organic frameworks (MOFs) have many promising applications in energy and environmental areas such as gas separation, catalysis, supercapacitors, and batteries; the key toward those applications is controlled pyrolysis which can tailor the porous structure, improve electrical conductivity, and expose metal ions in MOFs. Here, we present a systematic study on the structural evolution of zeolitic imidazolate frameworks hybridized on carbon nanotubes (CNTs) during the carbonization process. We show that a number of typical products can be obtained, depending on the annealing time, including (1) CNTs wrapped by relatively thick carbon layers, (2) CNTs grafted by ZnO nanoparticles which are covered by thin nitrogen-doped carbon layers, and (3) CNTs grafted by aggregated ZnO nanoparticles. We also investigated the electrochemical properties of those hybrid structures as freestanding membrane electrodes for lithium ion batteries, and the second one (CNT-supported ZnO covered by N-doped carbon) shows the best performance with a high specific capacity (850 mA h/g at a current density of 100 mA/g) and excellent cycling stability. Our results indicate that tailoring and optimizing the MOF-CNT hybrid structure is essential for developing high-performance energy storage systems.

Electrostatic Assembly of Nanomaterials for Hybrid Electrodes and Supercapacitors

Science.gov (United States)

Hammond, Paula

2015-03-01

Electrostatic assembly methods have been used to generate a range of new materials systems of interest for electrochemical energy and storage applications. Over the past several years, it has been demonstrated that carbon nanotubes, metals, metal oxides, polymeric nanomaterials, and biotemplated materials systems can be incorporated into ultrathin films to generate supercapacitors and battery electrodes that illustrate significant energy density and power. The unique ability to control the incorporation of such a broad range of materials at the nanometer length scale allows tailoring of the final properties of these unique composite systems, as well as the capability of creating complex micron-scale to nanoporous morphologies based on the scale of the nanomaterial that is absorbed within the structure, or the conditions of self-assembly. Recently we have expanded these capabilities to achieve new electrodes that are templated atop electrospun polmer fiber scaffolds, in which the polymer can be selectively removed to achieve highly porous materials. Spray-layer-by-layer and filtration methods of functionalized multiwall carbon nanotubes and polyaniline nanofibers enable the generation of electrode systems with unusually high surface. Incorporation of psuedocapacitive nanoparticles can enhance capacitive properties, and other catalytic or metallic nanoparticles can be implemented to enhance electrochemical or catalytic function.

An efficient analysis of nanomaterial cytotoxicity based on bioimpedance

International Nuclear Information System (INIS)

Kandasamy, Karthikeyan; Kim, Sanghyo; Choi, Cheol Soo

2010-01-01

In the emerging nanotechnology field, there is an urgent need for the development of a significant and sensitive method that can be used to analyse and compare the cytotoxicities of nanomaterials such as carbon nanotubes (CNTs) and gold nanoparticles (AuNPs), since such materials can be applied as contrast agents or drug delivery carriers. The bioimpedance system possesses great potential in many medical research fields including nanotechnology. Electric cell-substrate impedance sensing (ECIS) is a particular bioimpedance system that offers a real-time, non-invasive, and quantitative measurement method for the cytotoxicity of various materials. The present work compared the cytotoxicity of AuNPs to that of purchased single-walled carbon nanotubes (SWCNTs). The size-controlled and monodispersed AuNPs were synthesized under autoclaved conditions and reduced by ascorbic acid (AA) whereas the purchased SWCNTs were used without any surface modifications. Bioimpedance results were validated by conventional WST-1 and trypan blue assays, and transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) were performed to examine nanomaterials inside the VERO cells. This research evaluates the ability of the ECIS system compared to those of conventional methods in analyzing the cytotoxicity of AuNPs and SWCNTs with higher sensitivity under real-time conditions.

Nanomaterials and the environment: A review for the biennium 2008-2010

International Nuclear Information System (INIS)

Peralta-Videa, Jose R.; Zhao Lijuan; Lopez-Moreno, Martha L.; Rosa, Guadalupe de la; Hong Jie; Gardea-Torresdey, Jorge L.

2011-01-01

Applications of nanotechnology are touching almost every aspect of modern life. The increased use of engineered nanomaterials (ENMs) in consumer products, chemical and medical equipment, information technology, and energy, among others, has increased the number of publications (informative and scientific) on ENMs. By the 1950s, very few papers were committed to nanomaterials (NMs), but in 2009, more than 80,000 journal articles included the concept nanotechnology. The objective of this review is to compile and analyze publications on NMs in the biennium 2008-2010. This review includes the most recent publications in risk assessment/toxicity, characterization and stability, toxicity, fate and transport of NMs in terrestrial ecosystems, and new ENMs. Carbon nanotubes, metallic, metal oxides and hydroxides nanoparticles, quantum dots, and polystyrene NPs are included.

The Nanomaterial Registry: facilitating the sharing and analysis of data in the diverse nanomaterial community

Directory of Open Access Journals (Sweden)

Ostraat ML

2013-09-01

Full Text Available Michele L Ostraat, Karmann C Mills, Kimberly A Guzan, Damaris MurryRTI International, Durham, NC, USAAbstract: The amount of data being generated in the nanotechnology research space is significant, and the coordination, sharing, and downstream analysis of the data is complex and consistently deliberated. The complexities of the data are due in large part to the inherently complicated characteristics of nanomaterials. Also, testing protocols and assays used for nanomaterials are diverse and lacking standardization. The Nanomaterial Registry has been developed to address such challenges as the need for standard methods, data formatting, and controlled vocabularies for data sharing. The Registry is an authoritative, web-based tool whose purpose is to simplify the community's level of effort in assessing nanomaterial data from environmental and biological interaction studies. Because the registry is meant to be an authoritative resource, all data-driven content is systematically archived and reviewed by subject-matter experts. To support and advance nanomaterial research, a set of minimal information about nanomaterials (MIAN has been developed and is foundational to the Registry data model. The MIAN has been used to create evaluation and similarity criteria for nanomaterials that are curated into the Registry. The Registry is a publicly available resource that is being built through collaborations with many stakeholder groups in the nanotechnology community, including industry, regulatory, government, and academia. Features of the Registry website (https://www.nanomaterialregistry.org/ currently include search, browse, side-by-side comparison of nanomaterials, compliance ratings based on the quality and quantity of data, and the ability to search for similar nanomaterials within the Registry. This paper is a modification and extension of a proceedings paper for the Institute of Electrical and Electronics Engineers.Keywords: nanoinformatics

Graphene oxide vs. reduced graphene oxide as carbon support in porphyrin peroxidase biomimetic nanomaterials.

Science.gov (United States)

Socaci, C; Pogacean, F; Biris, A R; Coros, M; Rosu, M C; Magerusan, L; Katona, G; Pruneanu, S

2016-02-01

The paper describes the preparation of supramolecular assemblies of tetrapyridylporphyrin (TPyP) and its metallic complexes with graphene oxide (GO) and thermally reduced graphene oxide (TRGO). The two carbon supports are introducing different characteristics in the absorption spectra of the investigated nanocomposites. Raman spectroscopy shows that the absorption of iron-tetrapyridylporphyrin is more efficient on GO than TRGO, suggesting that oxygen functionalities are involved in the non-covalent interaction between the iron-porphyrin and graphene. The biomimetic peroxidase activity is investigated and the two iron-containing composites exhibit a better catalytic activity than each component of the assembly, and their cobalt and manganese homologues, respectively. The main advantages of this work include the demonstration of graphene oxide as a very good support for graphene-based nanomaterials with peroxidase-like activity (K(M)=0.292 mM), the catalytic activity being observed even with very small amounts of porphyrins (the TPyP:graphene ratio=1:50). Its potential application in the detection of lipophilic antioxidants (vitamin E can be measured in the 10(-5)-10(-4) M range) is also shown. Copyright © 2015 Elsevier B.V. All rights reserved.

Use of magnetic carbon composites from renewable resource materials for oil spill clean up and recovery

Science.gov (United States)

Viswanathan, Tito

2014-02-11

A method for separating a liquid hydrocarbon material from a body of water. In one embodiment, the method includes the steps of mixing a plurality of magnetic carbon-metal nanocomposites with a liquid hydrocarbon material dispersed in a body of water to allow the plurality of magnetic carbon-metal nanocomposites each to be adhered by an amount of the liquid hydrocarbon material to form a mixture, applying a magnetic force to the mixture to attract the plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material, and removing said plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material from said body of water while maintaining the applied magnetic force, wherein the plurality of magnetic carbon-metal nanocomposites is formed by subjecting one or more metal lignosulfonates or metal salts to microwave radiation, in presence of lignin/derivatives either in presence of alkali or a microwave absorbing material.

Design, demonstration and performance of a versatile electrospray aerosol generator for nanomaterial research and applications

International Nuclear Information System (INIS)

Jennerjohn, Nancy; Fung, David C; Hirakawa, Karen S; Hinds, William; Kennedy, Nola J; Eiguren-Fernandez, Arantzazu; Prikhodko, Sergey; Zavala-Mendez, Jose D

2010-01-01

Carbon nanotubes are difficult to aerosolize in a controlled manner. We present a method for generating aerosols not only of carbon nanotubes, but also of many reference and proprietary materials including quantum dots, diesel particulate matter, urban dust, and their mixtures, using electrospraying. This method can be used as a teaching tool, or as the starting point for advanced research, or to deliver nanomaterials in animal exposure studies. This electrospray system generates 180 μg of nanotubes per m 3 of carrier gas, and thus aerosolizes an occupationally relevant mass concentration of nanotubes. The efficiency achievable for single-walled carbon nanotubes is 9.4%. This system is simple and quick to construct using ordinary lab techniques and affordable materials. Since it is easy to replace soiled parts with clean ones, experiments on different types of nanomaterial can be performed back to back without contamination from previous experiments. In this paper, the design, fabrication, operation and characterization of our versatile electrospray method are presented. Also, the morphological changes that carbon nanotubes undergo as they make the transition from dry powders to aerosol particles are presented.

A comparative study of lung toxicity in rats induced by three types of nanomaterials

Science.gov (United States)

Lin, Zhiqing; Ma, Li; X, Zhu-ge; Zhang, Huashan; Lin, Bencheng

2013-12-01

The public is increasingly exposed to various engineered nanomaterials because of their mass production and wide application. Even when the biological effects of nanomaterials have been assessed, the underlying mechanisms of action in vivo are poorly understood. The present study was designed to seek a simple, effective, and oxidative stress-based biomarker system used for screening toxicity of nanomaterials. Nano-ferroso-ferric oxide (nano-Fe3O4), nano-silicon dioxide (nano-SiO2), and single-walled carbon nanotubes (SWCNTs) were dispersed in corn oil and characterized using transmission electron microscopy (TEM). Rats were exposed to the three nanomaterials by intratracheal instillation once every 2 days for 5 weeks. We investigated their lung oxidative and inflammatory damage by bronchoalveolar lavage fluid (BALF) detection and comparative proteomics by lung tissue. Two-dimensional electrophoresis (2-DE) of proteins isolated from the lung tissue, followed by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry, was performed. In the present study, we chose to detect lactate dehydrogenase, total antioxidant capacity, superoxide dismutase, and malondialdehyde as the biomarker system for screening the oxidative stress of nanomaterials and IL-6 as the inflammatory biomarker in BALF. Proteomics analysis revealed 17 differentially expressed proteins compared with the control group: nine were upregulated and eight were downregulated. Our results indicated that exposure by intratracheal instillation to any of the three typical nanomaterials may cause lung damage through oxidative damage and/or an inflammatory reaction.

Method for covering a spme fibre with carbon nanotubes and resulting spme fibre

OpenAIRE

Bertrán, Enric; Jover Comas, Eric; García Céspedes, Jordi; Bayona Termens, Josep María

2010-01-01

[EN] The invention relates to a method for covering solid phase microextraction (SPME) fibres with carbon nanotubes (CNT), comprising the following operations: (i) depositing a layer of a metal material on the SPME fibre; (ii) applying a heat treatment in order to form catalytic metal nanoparticles in a reducing atmosphere; and (iii) applying carbon using chemical deposition techniques, thereby forming CNT on top ofthe metal nanoparticles. The invention also relates to a fibre obtain...

Feasibility of Pb phytoextraction using nano-materials assisted ryegrass: Results of a one-year field-scale experiment.

Science.gov (United States)

Liang, Shu-Xuan; Jin, Yu; Liu, Wei; Li, Xiliang; Shen, Shi-Gang; Ding, Ling

2017-04-01

The effect of the combined application of nano-hydroxyapatite (NHAP) or nano-carbon black (NCB) on the phytoextraction of Pb by ryegrass was investigated as an enhanced remediation technique for soils by field-scale experiment. After the addition of 0.2% NHAP or NCB to the soil, temporal variation of the uptake of Pb in aboveground parts and roots were observed. Ryegrass shoot concentrations of Pb were lower with nano-materials application than without nano-materials for the first month. However, the shoot concentrations of Pb were significantly increased with nano-materials application, in particular NHAP groups. The ryegrass root concentrations of Pb were lower with nano-materials application for the first month. These results indicated that nano-materials had significant effects on stabilization of lead, especially at the beginning of the experiment. Along with the experimental proceeding, phytotoxicity was alleviated after the incorporation of nano-materials. The ryegrass biomass was significantly higher with nano-materials application. Consequently, the Pb phytoextraction potential of ryegrass significantly increased with nano-materials application compared to the gounps without nano-materials application. The total removal rates of soil Pb were higher after combined application of NHAP than NCB. NHAP is more suitable than NCB for in-situ remediation of Pb-contaminated soils. The ryegrass translocation factor exhibited a marked increase with time. It was thought that the major role of NHP and NBA might be to alleviate the Pb phytotoxicity and increase biomass of plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

Directory of Open Access Journals (Sweden)

José A. Rodríguez

2015-01-01

Full Text Available A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L−1, with a limit of detection of 1 mg L−1. The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P<0.05.

Safe use of nanomaterials

CERN Multimedia

2013-01-01

The use of nanomaterials  is on the increase worldwide, including at CERN. The HSE Unit has established a safety guideline to inform you of the main requirements for the safe handling and disposal of nanomaterials at CERN.   A risk assessment tool has also been developed which guides the user through the process of evaluating the risk for his or her activity. Based on the calculated risk level, the tool provides a list of recommended control measures.   We would therefore like to draw your attention to: Safety Guideline C-0-0-5 - Safe handling and disposal of nanomaterials; and Safety Form C-0-0-2 - Nanomaterial Risk Assessment   You can consult all of CERN’s safety rules and guidelines here. Please contact the HSE Unit for any questions you may have.   The HSE Unit

Black carbon semi-direct effects on cloud cover: review and synthesis

Directory of Open Access Journals (Sweden)

D. Koch

2010-08-01

Full Text Available Absorbing aerosols (AAs such as black carbon (BC or dust absorb incoming solar radiation, perturb the temperature structure of the atmosphere, and influence cloud cover. Previous studies have described conditions under which AAs either increase or decrease cloud cover. The effect depends on several factors, including the altitude of the AA relative to the cloud and the cloud type. We attempt to categorize the effects into several likely regimes. Cloud cover is decreased if the AAs are embedded in the cloud layer. AAs below cloud may enhance convection and cloud cover. AAs above cloud top stabilize the underlying layer and tend to enhance stratocumulus clouds but may reduce cumulus clouds. AAs can also promote cloud cover in convergent regions as they enhance deep convection and low level convergence as it draws in moisture from ocean to land regions. Most global model studies indicate a regional variation in the cloud response but generally increased cloud cover over oceans and some land regions, with net increased low-level and/or reduced upper level cloud cover. The result is a net negative semi-direct effect feedback from the cloud response to AAs. In some of these climate model studies, the cooling effect of BC due to cloud changes is strong enough to essentially cancel the warming direct effects.

Optimizing Energy Conversion: Magnetic Nano-materials