WorldWideScience

Sample records for carbon nanomaterial samples

  1. Mutagenicity of carbon nanomaterials

    DEFF Research Database (Denmark)

    Wallin, Håkan; Jacobsen, Nicklas Raun; White, Paul A;

    2011-01-01

    Carbon nanomaterials such carbon nanotubes, graphene and fullerenes are some the most promising nanomaterials. Although carbon nanomaterials have been reported to possess genotoxic potential, it is imperitive to analyse the data on the genotoxicity of carbon nanomaterials in vivo and in vitro...

  2. Dispersion medium modulates oxidative stress response of human lung epithelial cells upon exposure to carbon nanomaterial samples

    International Nuclear Information System (INIS)

    Due to their large specific surface area, the potential of nanoparticles to be highly reactive and to induce oxidative stress is particularly high. In addition, some types of nanoparticles contain transition metals as trace impurities which are known to generate reactive oxygen species (ROS) in biological systems. This study investigates the potential of two types of single-walled carbon nanotube samples, nanoparticulate carbon black and crocidolite asbestos to induce ROS in lung epithelial cells in vitro. Carbon nanotube and carbon black samples were used as produced, without further purification or processing, in order to best mimic occupational exposure by inhalation of airborne dust particles derived from carbon nanomaterial production. Intracellular ROS were measured following short-term exposure of primary bronchial epithelial cells (NHBE) and A549 alveolar epithelial carcinoma cells using the redox sensitive probe carboxydichlorofluorescin (carboxy-DCFDA). The oxidative potential of agglomerated nanomaterial samples was compared following dispersion in cell culture medium with and without foetal calf serum (FCS) supplement. In addition, samples were dispersed in dipalmitoylphosphatidylcholine (DPPC), the major component of lung surfactant. It could be illustrated that in vitro exposure of lung epithelial cells to carbon nanomaterial samples results only in moderate or low oxidative stress under the exposure conditions employed. However, cell responses are strongly dependent on the vehicle used for dispersion. Whereas the presence of DPPC increased intracellular ROS formation, FCS seemed to protect the cells from oxidative insult.

  3. Carbon Nanomaterials as Antibacterial Colloids

    Directory of Open Access Journals (Sweden)

    Michael Maas

    2016-07-01

    Full Text Available Carbon nanomaterials like graphene, carbon nanotubes, fullerenes and the various forms of diamond have attracted great attention for their vast potential regarding applications in electrical engineering and as biomaterials. The study of the antibacterial properties of carbon nanomaterials provides fundamental information on the possible toxicity and environmental impact of these materials. Furthermore, as a result of the increasing prevalence of resistant bacteria strains, the development of novel antibacterial materials is of great importance. This article reviews current research efforts on characterizing the antibacterial activity of carbon nanomaterials from the perspective of colloid and interface science. Building on these fundamental findings, recent functionalization strategies for enhancing the antibacterial effect of carbon nanomaterials are described. The review concludes with a comprehensive outlook that summarizes the most important discoveries and trends regarding antibacterial carbon nanomaterials.

  4. Carbon Nanomaterials as Antibacterial Colloids

    OpenAIRE

    Michael Maas

    2016-01-01

    Carbon nanomaterials like graphene, carbon nanotubes, fullerenes and the various forms of diamond have attracted great attention for their vast potential regarding applications in electrical engineering and as biomaterials. The study of the antibacterial properties of carbon nanomaterials provides fundamental information on the possible toxicity and environmental impact of these materials. Furthermore, as a result of the increasing prevalence of resistant bacteria strains, the development of ...

  5. 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

  6. Carbon Nanomaterials: Efficacy and Safety for Nanomedicine

    Directory of Open Access Journals (Sweden)

    Yasuo Tsutsumi

    2012-02-01

    Full Text Available Carbon nanomaterials, including fullerenes, carbon nanohorns, and carbon nanotubes, are increasingly being used in various fields owing to these materials’ unique, size-dependent functions and physicochemical properties. Recently, because of their high variability and stability, carbon nanomaterials have been explored as a novel tool for the delivery of therapeutic molecules including peptide and nucleic acid cancer drugs. However, insufficient information is available regarding the safety of carbon nanomaterials for human health, even though such information is vital for the development of safe and effective nanomedicine technologies. In this review, we discuss currently available information regarding the safety of carbon nanomaterials in nanomedicine applications, including information obtained from our own studies; and we discuss types of carbon nanomaterials that demonstrate particular promise for safe nanomedicine technologies.

  7. Carbon Nanomaterials for Road Construction

    Directory of Open Access Journals (Sweden)

    Zaporotskova Irina Vladimirovna

    2015-05-01

    Full Text Available The requirement of developing and modernizing the roads in Russia and in the Volgograd region in particular, is based on need of expanding the directions of scientific research on road and transport complexes. They have to be aimed at the development of the theory of transport streams, traffic safety increase, and, first of all, at the application of original methods of road development and modernization, introduction of modern technologies and road-building materials.On the basis of the analysis of the plans for transportation sphere development in the Volgograd region assuming the need to apply the new technologies allowing to create qualitative paving, the authors propose the technology of creating a heavy-duty paving with the use of carbon nanomaterial. The knowledge on strengthening the characteristics of carbon nanotubes is a unique material for nanotechnology development which allowed to assume the analysis of general information about asphalt concrete. The analysis showed that carbon nanotubes can be used for improvement of operational characteristics of asphalt concrete, and it is possible to carry out additives of nanotubes in hot as well as in cold bitumen. The article contains the basic principles of creation of the new road material received by means of bitumen reinforcing by carbon nanotubes. The structures received by the offered technique binding on the basis of the bitumens modified by carbon nanomaterial can be used for coverings and bases on highways of all categories in all road and climatic zones of Russia. The technical result consists in increasing the durability and elasticity of the received asphalt covering, and also the increase of water resistance, heat resistance and frost resistance, the expansion of temperature range of its laying in the field of negative temperatures.

  8. 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.

  9. 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.

  10. 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. PMID:24730288

  11. 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.

  12. Ice Nucleation Properties of Oxidized Carbon Nanomaterials.

    Science.gov (United States)

    Whale, Thomas F; Rosillo-Lopez, Martin; Murray, Benjamin J; Salzmann, Christoph G

    2015-08-01

    Heterogeneous ice nucleation is an important process in many fields, particularly atmospheric science, but is still poorly understood. All known inorganic ice nucleating particles are relatively large in size and tend to be hydrophilic. Hence it is not obvious that carbon nanomaterials should nucleate ice. However, in this paper we show that four different readily water-dispersible carbon nanomaterials are capable of nucleating ice. The tested materials were carboxylated graphene nanoflakes, graphene oxide, oxidized single walled carbon nanotubes and oxidized multiwalled carbon nanotubes. The carboxylated graphene nanoflakes have a diameter of ∼30 nm and are among the smallest entities observed so far to nucleate ice. Overall, carbon nanotubes were found to nucleate ice more efficiently than flat graphene species, and less oxidized materials nucleated ice more efficiently than more oxidized species. These well-defined carbon nanomaterials may pave the way to bridging the gap between experimental and computational studies of ice nucleation. PMID:26267196

  13. Quantification of carbon nanomaterials in vivo.

    Science.gov (United States)

    Wang, Haifang; Yang, Sheng-Tao; Cao, Aoneng; Liu, Yuanfang

    2013-03-19

    A diverse array of carbon nanomaterials (NMs), including fullerene, carbon nanotubes (CNTs), graphene, nanodiamonds, and carbon nanoparticles, have been discovered and widely applied in a variety of industries. Carbon NMs have been detected in the environment and have a strong possibility of entering the human body. The safety of carbon NMs has thus become a serious concern in academia and society. To achieve strict biosafety assessments, researchers need to fully understand the effects and fates of NMs in the human body, including information about absorption, distribution, metabolism, excretion, and toxicity (ADME/T). To acquire the ADME data, researchers must quantify NMs, but carbon NMs are very difficult to quantify in vivo. The carbon background in a typical biological system is high, particularly compared with the much lower concentration of carbon NMs. Moreover, carbon NMs lack a specific detection signal. Therefore, isotopic labeling, with its high sensitivity and specificity, is the first choice to quantify carbon NMs in vivo. Previously, researchers have used many isotopes, including ¹³C, ¹⁴C, ¹²⁵I, ¹³¹I, ³H, ⁶⁴Cu, ¹¹¹In, ⁸⁶Y, 99mTc, and ⁶⁷Ga, to label carbon NMs. We used these isotopic labeling methods to study the ADME of carbon NMs via different exposure pathways in animal models. Except for the metabolism of carbon NMs, which has seldom been investigated, significant amounts of data have been reported on the in vivo absorption, distribution, excretion, and toxicity of carbon NMs, which have revealed characteristic behaviors of carbon NMs, such as reticuloendothelial system (RES) capture. However, the complexity of the biological systems and diverse preparation and functionalization of the same carbon NMs have led to inconsistent results across different studies. Therefore, the data obtained so far have not provided a compatible and systematic profile of biosafety. Further efforts are needed to address these problems. In

  14. Structure and multiscale mechanics of carbon nanomaterials

    CERN Document Server

    2016-01-01

    This book aims at providing a broad overview on the relationship between structure and mechanical properties of carbon nanomaterials from world-leading scientists in the field. The main aim is to get an in-depth understanding of the broad range of mechanical properties of carbon materials based on their unique nanostructure and on defects of several types and at different length scales. Besides experimental work mainly based on the use of (in-situ) Raman and X-ray scattering and on nanoindentation, the book also covers some aspects of multiscale modeling of the mechanics of carbon nanomaterials.

  15. Carbon Nanomaterials as Reinforcements for Composites

    Science.gov (United States)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, S. L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Carbon nanomaterials including fellerenes, nanotubes (CNT) and nanofibers have been proposed for many applications. One of applications is to use the carbon nanomaterials as reinforcements for composites, especially for polymer matrices. Carbon nanotubes is a good reinforcement for lightweight composite applications due to its low mass density and high Young's modulus. Two obscures need to overcome for carbon nanotubes as reinforcements in composites, which are large quantity production and functioning the nanotubes. This presentation will discuss the carbon nanotube growth by chemical vapor deposition. In order to reduce the cost of producing carbon nanotubes as well as preventing the sliding problems, carbon nanotubes were also synthesized on carbon fibers. The synthesis process and characterization results of nanotubes and nanotubes/fibers will be discussed in the presentation.

  16. About aerogels based on carbon nanomaterials

    Directory of Open Access Journals (Sweden)

    Fail Sultanov

    2014-12-01

    Full Text Available In this review a current trends in development and application of carbon nanomaterials and derivatives based on them are presented. Aerogels based on graphene and other carbon nanomaterials present a class of novel ultralight materials in which a liquid phase is completely substituted by gaseous. In its turn graphene based aerogel was named as the lightest material, thus the record of aerographite, which has retained for a long time was beaten. Aerogels are characterized by low density, high surface area and high index of hydrophobicity. In addition, depending on its application, aerogels based on carbon nanomaterials can be electrically conductive and magnetic, while retaining the flexibility of its 3D structure. Impressive properties of novel material – aerogels causes a huge interest of scientists in order to find their application in various fields, ranging from environment problems to medicine and electronics.

  17. 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.

  18. 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.

  19. Influence of carbon nanomaterials on the properties of paint coatings

    Science.gov (United States)

    Zhdanok, S. A.; Krauklis, A. V.; Borisevich, K. O.; Prokopchuk, N. P.; Nikolaichik, A. V.; Stanovoi, P. G.

    2011-11-01

    The conditions for obtaining carbon nanomaterials with the use of a low-temperature plasma are described. The product obtained was analyzed using the electron microscopy and a laser diffraction particle-size analyzer. The influence of the carbon nanomaterials on the physicochemical properties of paint coatings, their adhesion, impact and bending strengths, hardness, and protection characteristics was investigated.

  20. Carbon nanomaterial based electrochemical sensors for biogenic amines

    International Nuclear Information System (INIS)

    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)

  1. Enzyme-catalyzed degradation of carbon nanomaterials

    Science.gov (United States)

    Kotchey, Gregg P.

    Carbon nanotubes and graphene, the nanoscale sp 2 allotropes of carbon, have garnered widespread attention as a result of their remarkable electrical, mechanical, and optical properties and the promise of new technologies that harness these properties. Consequently, these carbon nanomaterials (CNMs) have been employed for diverse applications such as electronics, sensors, composite materials, energy conversion devices, and nanomedicine. The manufacture and eventual disposal of these products may result in the release of CNMs into the environment and subsequent exposure to humans, animals, and vegetation. Given the possible pro-inflammatory and toxic effects of CNMs, much attention has been focused on the distribution, toxicity, and persistence of CNMs both in living systems and the environment. This dissertation will guide the reader though recent studies aimed at elucidating fundamental insight into the persistence of CNMs such as carbon nanotubes (CNTs) and graphene derivatives (i.e., graphene oxide and reduced graphene oxide). In particular, in-testtube oxidation/degradation of CNMs catalyzed by peroxidase enzymes will be examined, and the current understanding of the mechanisms underlying these processes will be discussed. Finally, an outlook of the current field including in vitro and in vivo biodegradation experiments, which have benefits in terms of human health and environmental safety, and future directions that could have implications for nanomedical applications such as imaging and drug delivery will be presented. Armed with an understanding of how and why CNMs undergo enzyme-catalyzed oxidation/biodegradation, researchers can tailor the structure of CNMs to either promote or inhibit these processes. For example, in nanomedical applications such as drug delivery, the incorporation of carboxylate functional groups could facilitate biodegradation of the nanomaterial after delivery of the cargo. Also, the incorporation of CNMs with defect sites in consumer

  2. Carbon nanomaterials: Biologically active fullerene derivatives.

    Science.gov (United States)

    Bogdanović, Gordana; Djordjević, Aleksandar

    2016-01-01

    Since their discovery, fullerenes, carbon nanotubes, and graphene attract significant attention of researches in various scientific fields including biomedicine. Nano-scale size and a possibility for diverse surface modifications allow carbon nanoallotropes to become an indispensable nanostructured material in nanotechnologies, including nanomedicine. Manipulation of surface chemistry has created diverse populations of water-soluble derivatives of fullerenes, which exhibit different behaviors. Both non-derivatized and derivatized fullerenes show various biological activities. Cellular processes that underline their toxicity are oxidative, genotoxic, and cytotoxic responses.The antioxidant/cytoprotective properties of fullerenes and derivatives have been considered in the prevention of organ oxidative damage and treatment. The same unique physiochemical properties of nanomaterials may also be associated with potential health hazards. Non-biodegradability and toxicity of carbon nanoparticles still remain a great concern in the area of biomedical application. In this review, we report on basic physical and chemical properties of carbon nano-clusters--fullerenes, nanotubes, and grapheme--their specificities, activities, and potential application in biological systems. Special emphasis is given to our most important results obtained in vitro and in vivo using polyhydroxylated fullerene derivative C₆₀(OH)₂₄. PMID:27483572

  3. Carbon Nanomaterials in Agriculture: A Critical Review.

    Science.gov (United States)

    Mukherjee, Arnab; Majumdar, Sanghamitra; Servin, Alia D; Pagano, Luca; Dhankher, Om Parkash; White, Jason C

    2016-01-01

    There has been great interest in the use of carbon nano-materials (CNMs) in agriculture. However, the existing literature reveals mixed effects from CNM exposure on plants, ranging from enhanced crop yield to acute cytotoxicity and genetic alteration. These seemingly inconsistent research-outcomes, taken with the current technological limitations for in situ CNM detection, present significant hurdles to the wide scale use of CNMs in agriculture. The objective of this review is to evaluate the current literature, including studies with both positive and negative effects of different CNMs (e.g., carbon nano-tubes, fullerenes, carbon nanoparticles, and carbon nano-horns, among others) on terrestrial plants and associated soil-dwelling microbes. The effects of CNMs on the uptake of various co-contaminants will also be discussed. Last, we highlight critical knowledge gaps, including the need for more soil-based investigations under environmentally relevant conditions. In addition, efforts need to be focused on better understanding of the underlying mechanism of CNM-plant interactions. PMID:26941751

  4. CARBON NANOMATERIALS IN AGRICULTURE: A CRITICAL REVIEW

    Directory of Open Access Journals (Sweden)

    Arnab eMukherjee

    2016-02-01

    Full Text Available AbstractThere has been great interest in the use of carbon nano-materials (CNMs in agriculture. However, the existing literature reveals mixed effects from CNM exposure on plants, ranging from enhanced crop yield to acute cytotoxicity and genetic alteration. These seemingly inconsistent research-outcomes, taken with the current technological limitations for in situ CNM detection, present significant hurdles to the wide scale use of CNMs in agriculture. The objective of this review is to evaluate the current literature, including studies with both positive and negative effects of different CNMs (e.g., carbon nano-tubes, fullerenes, carbon nanoparticles, and carbon nano-horns, among others on terrestrial plants and associated soil-dwelling microbes. The effects of CNMs on the uptake of various co-contaminants will also be discussed. Last, we highlight critical knowledge gaps, including the need for more soil-based investigations under environmentally relevant conditions. In addition, efforts need to be focused on better understanding of the underlying mechanism of CNM-plant interactions.

  5. Carbon Nanomaterials in Agriculture: A Critical Review

    Science.gov (United States)

    Mukherjee, Arnab; Majumdar, Sanghamitra; Servin, Alia D.; Pagano, Luca; Dhankher, Om Parkash; White, Jason C.

    2016-01-01

    There has been great interest in the use of carbon nano-materials (CNMs) in agriculture. However, the existing literature reveals mixed effects from CNM exposure on plants, ranging from enhanced crop yield to acute cytotoxicity and genetic alteration. These seemingly inconsistent research-outcomes, taken with the current technological limitations for in situ CNM detection, present significant hurdles to the wide scale use of CNMs in agriculture. The objective of this review is to evaluate the current literature, including studies with both positive and negative effects of different CNMs (e.g., carbon nano-tubes, fullerenes, carbon nanoparticles, and carbon nano-horns, among others) on terrestrial plants and associated soil-dwelling microbes. The effects of CNMs on the uptake of various co-contaminants will also be discussed. Last, we highlight critical knowledge gaps, including the need for more soil-based investigations under environmentally relevant conditions. In addition, efforts need to be focused on better understanding of the underlying mechanism of CNM-plant interactions. PMID:26941751

  6. Carbon Nanomaterials Interfacing with Neurons: An In vivo Perspective

    Science.gov (United States)

    Baldrighi, Michele; Trusel, Massimo; Tonini, Raffaella; Giordani, Silvia

    2016-01-01

    Developing new tools that outperform current state of the art technologies for imaging, drug delivery or electrical sensing in neuronal tissues is one of the great challenges in neurosciences. Investigations into the potential use of carbon nanomaterials for such applications started about two decades ago. Since then, numerous in vitro studies have examined interactions between these nanomaterials and neurons, either by evaluating their compatibility, as vectors for drug delivery, or for their potential use in electric activity sensing and manipulation. The results obtained indicate that carbon nanomaterials may be suitable for medical therapies. However, a relatively small number of in vivo studies have been carried out to date. In order to facilitate the transformation of carbon nanomaterial into practical neurobiomedical applications, it is essential to identify and highlight in the existing literature the strengths and weakness that different carbon nanomaterials have displayed when probed in vivo. Unfortunately the current literature is sometimes sparse and confusing. To offer a clearer picture of the in vivo studies on carbon nanomaterials in the central nervous system, we provide a systematic and critical review. Hereby we identify properties and behavior of carbon nanomaterials in vivo inside the neural tissues, and we examine key achievements and potentially problematic toxicological issues. PMID:27375413

  7. Carbon Nanomaterials Alter Global Gene Expression Profiles.

    Science.gov (United States)

    Woodman, Sara; Short, John C W; McDermott, Hyoeun; Linan, Alexander; Bartlett, Katelyn; Gadila, Shiva Kumar Goud; Schmelzle, Katie; Wanekaya, Adam; Kim, Kyoungtae

    2016-05-01

    Carbon nanomaterials (CNMs), which include carbon nanotubes (CNTs) and their derivatives, have diverse technological and biomedical applications. The potential toxicity of CNMs to cells and tissues has become an important emerging question in nanotechnology. To assess the toxicity of CNTs and fullerenol C60(OH)24, we in the present work used the budding yeast Saccharomyces cerevisiae, one of the simplest eukaryotic organisms that share fundamental aspects of eukaryotic cell biology. We found that treatment with CNMs, regardless of their physical shape, negatively affected the growth rates, end-point cell densities and doubling times of CNM-exposed yeast cells when compared to unexposed cells. To investigate potential mechanisms behind the CNMs-induced growth defects, we performed RNA-Seq dependent transcriptional analysis and constructed global gene expression profiles of fullerenol C60(OH)24- and CNT-treated cells. When compared to non-treated control cells, CNM-treated cells displayed differential expression of genes whose functions are implicated in membrane transporters and stress response, although differentially expressed genes were not consistent between CNT- and fullerenol C60(OH)24-treated groups, leading to our conclusion that CNMs could serve as environmental toxic factors to eukaryotic cells. PMID:27483901

  8. Carbon nanomaterials-based electrochemical aptasensors.

    Science.gov (United States)

    Wang, Zonghua; Yu, Jianbo; Gui, Rijun; Jin, Hui; Xia, Yanzhi

    2016-05-15

    Carbon nanomaterials (CNMs) have attracted increasing attention due to their unique electrical, optical, thermal, mechanical and chemical properties. CNMs are extensively applied in electronic, optoelectronic, photovoltaic and sensing devices fields, especially in bioassay technology. These excellent properties significantly depend on not only the functional atomic structures of CNMs, but also the interactions with other materials, such as gold nanoparticles, SiO2, chitosan, etc. This review systematically summarizes applications of CNMs in electrochemical aptasensors (ECASs). Firstly, definition and development of ECASs are introduced. Secondly, different ways of ECASs about working principles, classification and construction of CNMs are illustrated. Thirdly, the applications of different CNMs used in ECASs are discussed. In this review, different types of CNMs are involved such as carbon nanotubes, graphene, graphene oxide, etc. Besides, the newly emerging CNMs and CNMs-based composites are also discoursed. Finally, we demonstrate the future prospects of CNMs-based ECASs, and some suggestions about the near future development of CNMs-based ECASs are highlighted.

  9. 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

  10. Carbon Nanomaterials: Surface Structure and Morphology

    Science.gov (United States)

    Mansurov, Z. A.; Shabanova, T. A.; Mofa, N. N.; Glagolev, V. A.

    2014-09-01

    We propose a classification of individual nanoparticles on the basis of the form of the surface and the internal architectural packing for investigations carried out with the help of transmission electron microscopy. The investigated samples contain individual nanoparticles of seven kinds in different ratios: rounded, tubular, fibrous, fi lm, "veil," "active" particles and "particles with regular geometric contours." The classification was made on the basis of an analysis of the results of investigations of the surfaces and internal architectural packing of carbon particles obtained in different physiochemical processes (carbonization, carburizing, arc discharge, mechanochemical treatment, plasma chemistry, and in carbon-containing fl ames). For the source materials, we used waste of farming products and widely distributed mineral raw materials.

  11. Exploring Carbon Nanomaterial Diversity for Nucleation of Protein Crystals

    OpenAIRE

    Lata Govada; Hannah S. Leese; Emmanuel Saridakis; Sean Kassen; Benny Chain; Sahir Khurshid; Robert Menzel; Sheng Hu; Shaffer, Milo S. P.; Chayen, Naomi E.

    2016-01-01

    Controlling crystal nucleation is a crucial step in obtaining high quality protein crystals for structure determination by X-ray crystallography. Carbon nanomaterials (CNMs) including carbon nanotubes, graphene oxide, and carbon black provide a range of surface topographies, porosities and length scales; functionalisation with two different approaches, gas phase radical grafting and liquid phase reductive grafting, provide routes to a range of oligomer functionalised products. These grafted m...

  12. A critical review of glucose biosensors based on carbon nanomaterials: carbon nanotubes and graphene.

    Science.gov (United States)

    Zhu, Zhigang; Garcia-Gancedo, Luis; Flewitt, Andrew J; Xie, Huaqing; Moussy, Francis; Milne, William I

    2012-01-01

    There has been an explosion of research into the physical and chemical properties of carbon-based nanomaterials, since the discovery of carbon nanotubes (CNTs) by Iijima in 1991. Carbon nanomaterials offer unique advantages in several areas, like high surface-volume ratio, high electrical conductivity, chemical stability and strong mechanical strength, and are thus frequently being incorporated into sensing elements. Carbon nanomaterial-based sensors generally have higher sensitivities and a lower detection limit than conventional ones. In this review, a brief history of glucose biosensors is firstly presented. The carbon nanotube and grapheme-based biosensors, are introduced in Sections 3 and 4, respectively, which cover synthesis methods, up-to-date sensing approaches and nonenzymatic hybrid sensors. Finally, we briefly outline the current status and future direction for carbon nanomaterials to be used in the sensing area. PMID:22778628

  13. A Critical Review of Glucose Biosensors Based on Carbon Nanomaterials: Carbon Nanotubes and Graphene

    Directory of Open Access Journals (Sweden)

    William I. Milne

    2012-05-01

    Full Text Available There has been an explosion of research into the physical and chemical properties of carbon-based nanomaterials, since the discovery of carbon nanotubes (CNTs by Iijima in 1991. Carbon nanomaterials offer unique advantages in several areas, like high surface-volume ratio, high electrical conductivity, chemical stability and strong mechanical strength, and are thus frequently being incorporated into sensing elements. Carbon nanomaterial-based sensors generally have higher sensitivities and a lower detection limit than conventional ones. In this review, a brief history of glucose biosensors is firstly presented. The carbon nanotube and grapheme-based biosensors, are introduced in Sections 3 and 4, respectively, which cover synthesis methods, up-to-date sensing approaches and nonenzymatic hybrid sensors. Finally, we briefly outline the current status and future direction for carbon nanomaterials to be used in the sensing area.

  14. 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.

  15. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules.

    Science.gov (United States)

    Tiwari, Jitendra N; Vij, Varun; Kemp, K Christian; Kim, Kwang S

    2016-01-26

    The study of electrochemical behavior of bioactive molecules has become one of the most rapidly developing scientific fields. Biotechnology and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, we give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, we show how the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomolecules including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here we draw an important distinction between enzymeless and enzyme-containing carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field.

  16. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules.

    Science.gov (United States)

    Tiwari, Jitendra N; Vij, Varun; Kemp, K Christian; Kim, Kwang S

    2016-01-26

    The study of electrochemical behavior of bioactive molecules has become one of the most rapidly developing scientific fields. Biotechnology and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, we give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, we show how the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomolecules including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here we draw an important distinction between enzymeless and enzyme-containing carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field. PMID:26579616

  17. Combustion process for synthesis of carbon nanomaterials from liquid hydrocarbon

    Science.gov (United States)

    Diener, Michael D.; Alford, J. Michael; Nabity, James; Hitch, Bradley D.

    2007-01-02

    The present invention provides a combustion apparatus for the production of carbon nanomaterials including fullerenes and fullerenic soot. Most generally the combustion apparatus comprises one or more inlets for introducing an oxygen-containing gas and a hydrocarbon fuel gas in the combustion system such that a flame can be established from the mixed gases, a droplet delivery apparatus for introducing droplets of a liquid hydrocarbon feedstock into the flame, and a collector apparatus for collecting condensable products containing carbon nanomaterials that are generated in the combustion system. The combustion system optionally has a reaction zone downstream of the flame. If this reaction zone is present the hydrocarbon feedstock can be introduced into the flame, the reaction zone or both.

  18. Exploring Carbon Nanomaterial Diversity for Nucleation of Protein Crystals

    Science.gov (United States)

    Govada, Lata; Leese, Hannah S.; Saridakis, Emmanuel; Kassen, Sean; Chain, Benny; Khurshid, Sahir; Menzel, Robert; Hu, Sheng; Shaffer, Milo S. P.; Chayen, Naomi E.

    2016-02-01

    Controlling crystal nucleation is a crucial step in obtaining high quality protein crystals for structure determination by X-ray crystallography. Carbon nanomaterials (CNMs) including carbon nanotubes, graphene oxide, and carbon black provide a range of surface topographies, porosities and length scales; functionalisation with two different approaches, gas phase radical grafting and liquid phase reductive grafting, provide routes to a range of oligomer functionalised products. These grafted materials, combined with a range of controls, were used in a large-scale assessment of the effectiveness for protein crystal nucleation of 20 different carbon nanomaterials on five proteins. This study has allowed a direct comparison of the key characteristics of carbon-based nucleants: appropriate surface chemistry, porosity and/or roughness are required. The most effective solid system tested in this study, carbon black nanoparticles functionalised with poly(ethylene glycol) methyl ether of mean molecular weight 5000, provides a novel highly effective nucleant, that was able to induce crystal nucleation of four out of the five proteins tested at metastable conditions.

  19. 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.

  20. Carbon Nanomaterials: Applications in Physico-chemical Systemsand Biosystems

    Directory of Open Access Journals (Sweden)

    Maheshwar Sharon

    2008-07-01

    Full Text Available In the present article, various forms of carbon and carbon nanomaterials (CNMs and a new approach to classify them on the basis of sp2-sp3 configuration are presented. Utilising the concept of junction formation (like p:n junction a concept is developed to explain the special reactivity of nanosized carbon materials. Geometric consideration of chiral and achiral symmetry of single-walled carbon nanotubes is presented which is also responsible for manifesting special propertiesof carbon nanotubes. A brief introduction to various common synthesis techniques of CNMs is given. These is increased chemical and biological activities have resulted in many engineer ednanoparticles, which are being designed for specific purposes, including diagnostic or the rapeuticmedical uses and environmental remediation.Defence Science Journal, 2008, 58(4, pp.460-485, DOI:http://dx.doi.org/10.14429/dsj.58.1668

  1. Phase conversion in silicon and carbon nanomaterials at extreme pressure

    Science.gov (United States)

    Crane, Matthew; Smith, Bennett; Abramson, Evan; Pauzauskie, Peter

    The high pressures and temperatures accessible in laser-heated diamond anvil cells (LH-DAC) have produced fundamental insights by identifying metastable states with extraordinary properties. However, the actual conditions necessary to access a metastable state depend on the kinetics of phase transformation. The explosion of research in nanomaterials has generated interest in exploring how phase transformations occur in materials with high radii of curvature, and how we can leverage these effects. We present work investigating phase transformations in Si- and C-based nanomaterials with high radii of curvature. We have loaded a LH-DAC with Si nanowires (NWs) and examined the phase at a range of pressures to discover a recoverable phase transition to a wurtzite crystal structure. For C materials, we have synthesized a pyrolyzed carbon aerogel, an amorphous carbon sol gel with size features of ~10 nm and incredibly low density and thermal conductivity (~10-2 W/m-K). We investigate spatial resolution of heating under pressure and the effect of temperature on resulting material electronic structure. Finally, we model heating with Mie theory to provide insights into the phase transformations of nanomaterials.

  2. Ecotoxicological effects of carbon nanomaterials on algae, fungi and plants.

    Science.gov (United States)

    Basiuk, Elena V; Ochoa-Olmos, Omar E; De la Mora-Estrada, León F

    2011-04-01

    The ecotoxicological effects of carbon nanomateriales (CNMs), namely fullerenes and carbon nanotubes, on algae, fungi and plants are analyzed. In different toxicity tests, both direct and indirect effects were found. The direct effects are determined by nanomaterial chemical composition and surface reactivity, which might catalyze redox reactions in contact with organic molecules and affect respiratory processes. Some indirect effects of carbon nanoparticles (CNPs) are physical restraints or release of toxic ions. Accumulation of CNPs in photosynthetic organs provokes obstruction in stomata, foliar heating and alteration in physiological processes. The phytotoxicity studies of CNMs should be focused on determining phytotoxicity mechanisms, size distribution of CNPs in solution, uptake and translocation of nanoparticles by plants, on characterization of their physical and chemical properties in rhizosphere and on root surfaces. More studies on plants and algae, as a part of food chain, are needed to understand profoundly the toxicity and health risks of CNMs as ecotoxicological stressors. Correct and detailed physical and chemical characterization of CNMs is very important to establish the exposure conditions matching the realistic ones. Ecotoxicity experiments should include examinations of both short and long-term effects. One must take into account that real carbon nanomaterials are complex mixtures of carbon forms and metal residues of variable chemistry and particle size, and the toxicity reported may reflect these byproducts/residues/impurities rather than the primary material structure. One more recommendation is not only to focus on the inherent toxicity of nanoparticles, but also consider their possible interactions with existing environmental contaminants.

  3. 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

  4. Carbon nanomaterials in silica aerogel matrices

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Christopher E [Los Alamos National Laboratory; Chavez, Manuel E [Los Alamos National Laboratory; Duque, Juan G [Los Alamos National Laboratory; Gupta, Gautam [Los Alamos National Laboratory; Doorn, Stephen K [Los Alamos National Laboratory; Dattelbaum, Andrew M [Los Alamos National Laboratory; Obrey, Kimberly A D [Los Alamos National Laboratory

    2010-01-01

    Silica aerogels are ultra low-density, high surface area materials that are extremely good thermal insulators and have numerous technical applications. However, their mechanical properties are not ideal, as they are brittle and prone to shattering. Conversely, single-walled carbon nanotubes (SWCNTs) and graphene-based materials, such as graphene oxide, have extremely high tensile strength and possess novel electronic properties. By introducing SWCNTs or graphene-based materials into aerogel matrices, it is possible to produce composites with the desirable properties of both constituents. We have successfully dispersed SWCNTs and graphene-based materials into silica gels. Subsequent supercritical drying results in monolithic low-density composites having improved mechanical properties. These nanocomposite aerogels have great potential for use in a wide range of applications.

  5. Photocatalytic composites based on titania nanoparticles and carbon nanomaterials

    Science.gov (United States)

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

    2015-09-01

    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.

  6. Scanning Electrochemical Microscopy of Carbon Nanomaterials and Graphite.

    Science.gov (United States)

    Amemiya, Shigeru; Chen, Ran; Nioradze, Nikoloz; Kim, Jiyeon

    2016-09-20

    Carbon materials are tremendously important as electrode materials in both fundamental and applied electrochemistry. Recently, significant attention has been given not only to traditional carbon materials, but also to carbon nanomaterials for various electrochemical applications in energy conversion and storage as well as sensing. Importantly, many of these applications require fast electron-transfer (ET) reactions between a carbon surface and a redox-active molecule in solution. It, however, has not been well understood how heterogeneous ET kinetics at a carbon/solution interface is affected by the electronic structure, defect, and contamination of the carbon surface. Problematically, it is highly challenging to measure the intrinsic electrochemical reactivity of a carbon surface, which is readily passivated by adventitious organic contaminants. This Account summarizes our recent studies of carbon nanomaterials and graphite by scanning electrochemical microscopy (SECM) not only to reveal the fast ET kinetics of simple ferrocene derivatives at their graphitic surfaces, but also to obtain mechanistic insights into their extraordinary electrochemical reactivity. Specifically, we implemented new principles and technologies to reliably and reproducibly enable nanoscale SECM measurements. We took advantage of a new SECM imaging principle to resolve the high reactivity of the sidewall of individual single walled carbon nanotubes. In addition, we developed SECM-based nanogap voltammetry to find that monolayer graphene grown by chemical vapor deposition yields an unprecedentedly high standard ET rate constant, k(0), of ≥25 cm/s, which was >1000 times higher than that reported in the literature. Remarkably, the nonideal asymmetry of paired nanogap voltammograms revealed that the high reactivity of graphitic surfaces is compromised by their contamination with airborne hydrocarbons. Most recently, we protected the clean surface of highly oriented pyrolytic graphite from the

  7. Carbon Nanomaterials and DNA: from Molecular Recognition to Applications.

    Science.gov (United States)

    Sun, Hanjun; Ren, Jinsong; Qu, Xiaogang

    2016-03-15

    DNA is polymorphic. Increasing evidence has indicated that many biologically important processes are related to DNA's conformational transition and assembly states. In particular, noncanonical DNA structures, such as the right-handed A-form, the left-handed Z-form, the triplex, the G-quadruplex, the i-motif, and so forth, have been specific targets for the diagnosis and therapy of human diseases. Meanwhile, they have been widely used in the construction of smart DNA nanomaterials and nanoarchitectures. As rising stars in materials science, the family of carbon nanomaterials (CNMs), including two-dimensional graphene, one-dimensional carbon nanotubes (CNTs), and zero-dimensional graphene or carbon quantum dots (GQDs or CQDs), interact with DNA and are able to regulate the conformational transitions of DNA. The interaction of DNA with CNMs not only opens new opportunities for specific molecular recognition, but it also expands the promising applications of CNMs from materials science to biotechnology and biomedicine. In this Account, we focus on our contributions to the field of interactions between CNMs and DNA in which we have explored their promising applications in nanodevices, sensing, materials synthesis, and biomedicine. For one-dimensional CNTs, two-dimensional graphene, and zero-dimensional GQDs and CQDs, the basic principles, binding modes, and applications of the interactions between CNMs and DNA are reviewed. We aim to give prominence to the important status of CNMs in the field of molecular recognition for DNA. First, we summarized our discovery of the interactions between single-walled carbon nanotubes (SWNTs) with duplex, triplex, and human telomeric i-motif DNA and their interesting applications. For example, SWNTs are the first chemical agents that can selectively stabilize human telomeric i-motif DNA and induce its formation under physiological conditions. On the basis of this principle, two types of nanodevices were designed. One was used for

  8. Highly energetic compositions based on functionalized carbon nanomaterials

    Science.gov (United States)

    Yan, Qi-Long; Gozin, Michael; Zhao, Feng-Qi; Cohen, Adva; Pang, Si-Ping

    2016-02-01

    In recent years, research in the field of carbon nanomaterials (CNMs), such as fullerenes, expanded graphite (EG), carbon nanotubes (CNTs), graphene, and graphene oxide (GO), has been widely used in energy storage, electronics, catalysts, and biomaterials, as well as medical applications. Regarding energy storage, one of the most important research directions is the development of CNMs as carriers of energetic components by coating or encapsulation, thus forming safer advanced nanostructures with better performances. Moreover, some CNMs can also be functionalized to become energetic additives. This review article covers updated preparation methods for the aforementioned CNMs, with a more specific orientation towards the use of these nanomaterials in energetic compositions. The effects of these functionalized CNMs on thermal decomposition, ignition, combustion and the reactivity properties of energetic compositions are significant and are discussed in detail. It has been shown that the use of functionalized CNMs in energetic compositions greatly improves their combustion performances, thermal stability and sensitivity. In particular, functionalized fullerenes, CNTs and GO are the most appropriate candidate components in nanothermites, solid propellants and gas generators, due to their superior catalytic properties as well as facile preparation methods.

  9. Carbon Nanomaterials for Energy Storage, Actuators and Environmental Applications

    Science.gov (United States)

    Wang, Chengwei

    Carbon nanomaterials have caught tremendous attention in the last few decades due to their unique physical and chemical properties. Tremendous effort has been made to develop new synthesis techniques for carbon nanomaterials and investigate their properties for different applications. In this work, carbon nanospheres (CNSs), carbon foams (CF), and single-walled carbon nanotubes (SWNTs) were studied for various applications, including water treatment, energy storage, actuators, and sensors. A facile spray pyrolysis synthesis technique was developed to synthesize individual CNSs with specific surface area (SSA) up to 1106 m2/g. The hollow CNSs showed adsorption of up to 300 mg rhodamine B dye per gram carbon, which is more than 15 times higher than that observed for conventional carbon black. They were also evaluated as adsorbents for removal of arsenate and selenate from water and displayed good binding to both species, outperforming commercial activated carbons for arsenate removal in pH > 8. When evaluated as supercapacitor electrode materials, specific capacitances of up to 112 F/g at a current density of 0.1 A/g were observed. When used as Li-ion battery anode materials, the CNSs achieved a discharge capacity of 270 mAh/g at a current density of 372 mA/g (1C), which is 4-fold higher than that of commercial graphite anode. Carbon foams were synthesized using direct pyrolysis and had SSA up to 2340 m2/g. When used as supercapacitor electrode materials, a specific capacitance up to 280 F/g was achieved at current density of 0.1 A/g and remained as high as 207 F/g, even at a high current density of 10 A/g. A printed walking robot was made from common plastic films and coatings of SWNTs. The solid-state thermal bimorph actuators were multifunctional energy transducers powered by heat, light, or electricity. The actuators were also investigated for photo/thermal detection. Electrochemical actuators based on MnO2 were also studied for potential underwater applications

  10. 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.

  11. Carbon nanomaterials as counter electrodes for dye solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Aitola, K.

    2012-07-01

    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

  12. 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.

  13. Dimensionality of carbon nanomaterial impacting on the modulation of amyloid peptide assembly

    Science.gov (United States)

    Wang, J.; Zhu, Z.; Bortolini, C.; Hoffmann, S. V.; Amari, A.; Zhang, H. X.; Liu, L.; Dong, M. D.

    2016-07-01

    A wide variety of inorganic nanomaterials have been exploited so far for their great potential for biological applications. Some of these materials could be valid candidates to modulate the assembly of amyloid peptides, which is relevant to amyloid-related diseases. In this work, we reveal that a carbon nanomaterial can indeed modulate the assembly of amyloid peptides and, additionally, we show that this modulating effect is closely related to the dimensionality of the nanomaterials.

  14. Dimensionality of carbon nanomaterial impacting on the modulation of amyloid peptide assembly

    DEFF Research Database (Denmark)

    Wang, J.; Zhu, Z.; Bortolini, C.;

    2016-01-01

    A wide variety of inorganic nanomaterials have been exploited so far for their great potential for biological applications. Some of these materials could be valid candidates to modulate the assembly of amyloid peptides, which is relevant to amyloid-related diseases. In this work, we reveal...... that a carbon nanomaterial can indeed modulate the assembly of amyloid peptides and, additionally, we show that this modulating effect is closely related to the dimensionality of the nanomaterials....

  15. Enhanced Synthesis of Carbon Nanomaterials Using Acoustically Excited Methane Diffusion Flames

    Directory of Open Access Journals (Sweden)

    Shuhn-Shyurng Hou

    2015-07-01

    Full Text Available Acoustically modulated methane jet diffusion flames were used to enhance carbon nanostructure synthesis. A catalytic nickel substrate was employed to collect the deposit materials at sampling position z = 10 mm above the burner exit. The fabrication of carbon nano-onions (CNOs and carbon nanotubes (CNTs was significantly enhanced by acoustic excitation at frequencies near the natural flickering frequency (ƒ = 20 Hz and near the acoustically resonant frequency (ƒ = 90 Hz, respectively. At these characteristic frequencies, flow mixing was markedly enhanced by acoustic excitation, and a flame structure with a bright slender core flame was generated, which provided a favorable flame environment for the growth of carbon nanomaterials. The production rate of CNOs was high at 20 Hz (near the natural flickering frequency, at which the gas temperature was about 680 °C. Additionally, a quantity of CNTs was obtained at 70–95 Hz, near the acoustically resonant frequency, at which the gas temperature was between 665 and 830 °C. However, no carbon nanomaterials were synthesized at other frequencies. The enhanced synthesis of CNOs and CNTs is attributed to the strong mixing of the fuel and oxidizer due to the acoustic excitation at resonant frequencies.

  16. 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.

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

    Science.gov (United States)

    Susi, Toma; Pichler, Thomas; Ayala, Paola

    2015-01-01

    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.

  18. 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.

  19. Hydrogen Storage in Boron Nitride and Carbon Nanomaterials

    Directory of Open Access Journals (Sweden)

    Takeo Oku

    2014-12-01

    Full Text Available Boron nitride (BN nanomaterials were synthesized from LaB6 and Pd/boron powder, and the hydrogen storage was investigated by differential thermogravimetric analysis, which showed possibility of hydrogen storage of 1–3 wt%. The hydrogen gas storage in BN and carbon (C clusters was also investigated by molecular orbital calculations, which indicated possible hydrogen storage of 6.5 and 4.9 wt%, respectively. Chemisorption calculation was also carried out for B24N24 cluster with changing endohedral elements in BN cluster to compare the bonding energy at nitrogen and boron, which showed that Li is a suitable element for hydrogenation to the BN cluster. The BN cluster materials would store H2 molecule easier than carbon fullerene materials, and its stability for high temperature would be good. Molecular dynamics calculations showed that a H2 molecule remains stable in a C60 cage at 298 K and 0.1 MPa, and that pressures over 5 MPa are needed to store H2 molecules in the C60 cage.

  20. Hypergravity synthesis of graphitic carbon nanomaterial in glide arc plasma

    NARCIS (Netherlands)

    J. Šperka; P. Soucek; J.J.W.A. van Loon; A. Dowson; C. Schwarz; J. Krause; Y. Butenko; G. Kroesen; V. Kudrle

    2014-01-01

    A nanostructured carbon material was synthesized using a methane/helium glide arc plasma under standard and increased gravity. Material analysis performed on samples collected from an effluent gas filter showed that the deposited material was present in the form of carbon nanoparticles. They exhibit

  1. Applications of Carbon-Based Nanomaterials for Drug Delivery in Oncology

    Science.gov (United States)

    Levi-Polyachenko, Nicole H.; Carroll, David L.; Stewart, John H.

    The goal of this chapter is to introduce carbon nanomaterials and highlight research focused on their use as cancer therapeutics. The physical properties of fullerenes and carbon nanotubes, including their spectral characteristics are described. Current oncology treatment regimes are described to provide an overview of where carbon nanomaterials may have significant value in further development of the established standards of care procedures. Photodynamic therapy and drug delivery using fullerene C60 is explored. Thermal ablation techniques using carbon nanotubes are explained and alternate hyperthermic methods using carbon nanotubes are described. Specifically, carbon nanotubes are examined for their potential contribution to the currently practiced clinical therapy intraperitoneal hyperthermic chemoperfusion. Nanotubes and nanohorns filled with chemotherapeutic agents are examined as are different methods for filling and containment of drug moieties. The attachment of active molecules to fullerenes is described with examples for use in oncology. Toxicity issues are explored and the future directions and potential for carbon nanomaterial types concludes the chapter.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  4. Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cheng; Denno, Madelaine E.; Pyakurel, Poojan; Venton, B. Jill, E-mail: jventon@virginia.edu

    2015-08-05

    Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors. - Highlights: • We review the types of carbon nanomaterials used in electrochemical sensors. • Different materials and sensor designs are compared for classes of biomolecules. • Future challenges of better sensor design and implementation are assessed.

  5. Structural Characterization of Carbon Nanomaterial Film In Situ Synthesized on Various Bulk Metals

    Directory of Open Access Journals (Sweden)

    J. Y. Xu

    2014-01-01

    Full Text Available Carbon nanofiber films were prepared via a simple chemical vapor deposition (CVD method on various bulk metal substrates including bulk 316 L stainless steel, pure cobalt, and pure nickel treated by surface mechanical attrition treatment (SMAT. The microstructures of the carbon nanomaterial film were studied by SEM, TEM, XRD, and Raman spectroscopy. In this paper, bulk metallic materials treated by SMAT served as substrates as well as catalysts for carbon nanomaterial film formation. The results indicate that the carbon nanofiber films are formed concerning the catalytic effects of the refined metallic particles during CVD on the surface of SMAT-treated bulk metal substrates. However, distinguished morphologies of carbon nanomaterial film are displayed in the case of the diverse bulk metal substrates.

  6. Two- and Three-Dimensional All-Carbon Nanomaterial Assemblies for Tissue Engineering and Regenerative Medicine.

    Science.gov (United States)

    Lalwani, Gaurav; Patel, Sunny C; Sitharaman, Balaji

    2016-06-01

    Carbon nanomaterials such as carbon nanotubes and graphene have gained significant interest in the fields of materials science, electronics and biomedicine due to their interesting physiochemical properties. Typically these carbon nanomaterials have been dispersed in polymeric matrices at low concentrations to improve the functional properties of nanocomposites employed as two-dimensional (2D) substrates or three-dimensional (3D) porous scaffolds for tissue engineering applications. There has been a growing interest in the assembly of these nanomaterials into 2D and 3D architectures without the use of polymeric matrices, surfactants or binders. In this article, we review recent advances in the development of 2D or 3D all-carbon assemblies using carbon nanotubes or graphene as nanoscale building-block biomaterials for tissue engineering and regenerative medicine applications.

  7. Two- and Three-Dimensional All-Carbon Nanomaterial Assemblies for Tissue Engineering and Regenerative Medicine.

    Science.gov (United States)

    Lalwani, Gaurav; Patel, Sunny C; Sitharaman, Balaji

    2016-06-01

    Carbon nanomaterials such as carbon nanotubes and graphene have gained significant interest in the fields of materials science, electronics and biomedicine due to their interesting physiochemical properties. Typically these carbon nanomaterials have been dispersed in polymeric matrices at low concentrations to improve the functional properties of nanocomposites employed as two-dimensional (2D) substrates or three-dimensional (3D) porous scaffolds for tissue engineering applications. There has been a growing interest in the assembly of these nanomaterials into 2D and 3D architectures without the use of polymeric matrices, surfactants or binders. In this article, we review recent advances in the development of 2D or 3D all-carbon assemblies using carbon nanotubes or graphene as nanoscale building-block biomaterials for tissue engineering and regenerative medicine applications. PMID:27126776

  8. Enhanced thermal conductivity of n-octadecane containing carbon-based nanomaterials

    Science.gov (United States)

    Motahar, Sadegh; Alemrajabi, Ali A.; Khodabandeh, Rahmatollah

    2016-08-01

    In the present study, carbon-based nanomaterials including multiwalled carbon nanotubes (MWCNTs) and vapor-grown carbon nanofibers (CNFs) were dispersed in n-octadecane as a phase change material (PCM) at various mass fractions of 0.5, 1, 2 and 5 wt% by the two-step method. The transient plane source technique was used to measure thermal conductivity of samples at various temperatures in solid (5-25 °C) and liquid (30-55 °C) phases. The experimental results showed that thermal conductivity of the composites increases with increasing the loading of the MWCNTs and CNFs. A maximum thermal conductivity enhancement of 36 % at 5 wt% MWCNTs and 5 °C as well as 50 % at 2 wt% and 55 °C were experimentally obtained for n-octadecane/MWCNTs samples. Dispersing CNFs into n-octadecane raised the thermal conductivity up to 18 % at 5 wt% and 10 °C and 21 % at 5 wt% and 55 °C. However, the average enhancement of 19 and 21 % for solid and liquid phases of MWCNTs composite as well as 33 and 46 % for solid and liquid phase of CNFs promised a better heat transfer characteristics of MWCNTs in n-octadecane. A comparison between results of the present work and available literature revealed a satisfactory enhancement of thermal conductivity. For the investigated n-octadecane/MWCNTs and n-octadecane/CNFs composites, a new correlation was proposed for predicting the thermal conductivity as a function of temperature and nanomaterials loading.

  9. Copper-cerium oxides supported on carbon nanomaterial for preferential oxidation of carbon monoxide

    Institute of Scientific and Technical Information of China (English)

    高美怡; 江楠; 赵宇宏; 徐长进; 苏海全; 曾尚红

    2016-01-01

    The CuxO-CeO2/Fe@CNSs, CuxO-CeO2/MWCNTs-Co and CuxO-CeO2/MWCNTs-Ni catalysts were prepared by the im-pregnation method and characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffrac-tion, H2-temperature programmed reduction and N2 adsorption-desorption techniques. It was found that the Fe nanoparticles were encapsulated into the multi-layered carbon nanospheres (CNSs). However, the multi-wall carbon nanotubes (MWCNTS) were generated on the Co/Al2O3 and Ni/Al2O3 precursor. The addition of carbon nanomaterial as supports could improve structural properties and low-temperature activity of the CuO-CeO2 catalyst, and save the used amount of metal catalysts in the temperature range with high selectivity for CO oxidation. The copper-cerium oxides supported on carbon nanomaterial had good resistence to H2O and CO2.

  10. High performance supercapacitor using porous carbon nanomaterial from corn cob

    Science.gov (United States)

    Sharma, Nallin; Mishra, Neeraj; Sharon, Madhuri; Sharon, Maheshwar

    2013-06-01

    Carbon synthesized from corn-cob has been used as an electrode in Electrochemical Double Layer Capacitor (EDLC). Dried Corn Cobs, soaked in 1N KOH, 1N HCl or 5% ZnCl2 at 10 0°C for 24 hr, were pyrolyzed in presence of Ar using Co as catalyst at 700-900 °C having dwell time of 60-180 min. The morphology of thus obtained carbon was studied under SEM that showed it to be porous carbon. All the carbon samples synthesized using different parameters were used as electrode for EDLC. Cyclic Voltammetry was used to measure the capacitance. Carbon synthesized from corn cobs pre-treated with 5% ZnCl2 using Co as catalyst pyrolyzed at 700°C for a dwell time of 120 min gave higher Specific capacitance of 270 F/g at scan rate of 5 mV/s. Moreover, this carbon, as observed under SEM, exhibited larger pore size.

  11. Development of effective nanobiocatalytic systems through the immobilization of hydrolases on functionalized carbon-based nanomaterials

    NARCIS (Netherlands)

    Pavlidis, Ioannis V.; Vorhaben, Torge; Tsoufis, Theodoros; Rudolf, Petra; Bornscheuer, Uwe T.; Gournis, Dimitrios; Stamatis, Haralambos

    2012-01-01

    In this study we report the use of functionalized carbon-based nanomaterials, such as amine-functionalized graphene oxide (GO) and multi-walled carbon nanotubes (CNTs), as effective immobilization supports for various lipases and esterases of industrial interest. Structural and biochemical character

  12. Volatile-nanoparticle-assisted optical visualization of individual carbon nanotubes and other nanomaterials.

    Science.gov (United States)

    Jian, Muqiang; Xie, Huanhuan; Wang, Qi; Xia, Kailun; Yin, Zhe; Zhang, Mingyu; Deng, Ningqin; Wang, Luning; Ren, Tianling; Zhang, Yingying

    2016-07-21

    The development of nanomaterials has put forward high requirements for characterization techniques. Optical microscopy (OM), with easy accessibility and open operating spaces as compared to scanning electron microscopy, is a good choice to quickly locate materials and to be integrated with other equipment. However, OM is limited by its low resolution. Herein, we present a facile and non-destructive approach for optical observation of nanomaterials under conventional OMs with the aid of volatile nanoparticles (NPs), which can be deposited and removed in a controlled manner. The NPs deposited on the surface of nanomaterials render strong light scattering to enable the nanomaterials to become optically visible. For example, this approach enables the observation of individual carbon nanotubes (CNTs) with OMs at low magnification or even with the naked eye. Both supported CNTs on various substrates and suspended CNTs can be observed with this approach. Most importantly, the NPs can be completely removed through moderate heat treatment or laser irradiation, avoiding potential influence on the properties or subsequent applications of nanomaterials. Furthermore, we systematically investigate the deposition of various volatile NPs (up to 14 kinds) for the optical observation of nanomaterials. We also demonstrated the application of this approach on other nanomaterials, including nanowires and graphene. We showed that this approach is facile, controllable, non-destructive, and contamination-free, indicating wide potential applications. PMID:27350415

  13. Nanomechanical IR Spectroscopy for the fast analysis of picogram samples of engineered nanomaterials

    DEFF Research Database (Denmark)

    Andersen, Alina Joukainen; Ek, Pramod Kumar; Andresen, Thomas Lars;

    2014-01-01

    The proliferation of engineered nanomaterials (ENMs), e.g. in nanomedicine, demands for novel sensitive techniques allowing for the analysis of minute samples. We present nanoelectromechanical system-based IR spectroscopy (NEMS-IR) of picograms of polymeric micelles. The micelles are nebulized...

  14. 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

  15. Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review.

    Science.gov (United States)

    Yang, Cheng; Denno, Madelaine E; Pyakurel, Poojan; Venton, B Jill

    2015-08-01

    Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors.

  16. 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.

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

    Science.gov (United States)

    Adhikari, Bal-Ram; Govindhan, Maduraiveeran; Chen, Aicheng

    2015-01-01

    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. PMID:26404304

  18. Novel pot-shaped carbon nanomaterial synthesized in a submarine-style substrate heating CVD method

    OpenAIRE

    Yokoi, Hiroyuki; Hatakeyama, Kazuto; Taniguchi, Takaaki; Koinuma, Michio; Hara, Masahiro; Matsumoto, Yasumichi; ヨコイ, ヒロユキ; ハタケヤマ, カズト; タニグチ, タカアキ; コイヌマ, ミチオ; ハラ, マサヒロ; マツモト, ヤスミチ; 横井, 裕之; 畠山, 一翔; 谷口, 貴章

    2016-01-01

    We have developed a new synthesis method that includes a chemical vapor deposition process in a chamber settled in organic liquid, and applied its nonequilibrium reaction field to the development of novel carbon nanomaterials. In the synthesis at 1110-1120 K, using graphene oxide as a catalyst support, iron acetate and cobalt acetate as catalyst precursors, and 2-propanol as a carbon source as well as the organic liquid, we succeeded to create carbon nanofiber composed of novel pot-shaped uni...

  19. Fabrication and Optimization of Carbon Nanomaterial-Based Lithium-Ion Battery Anodes

    OpenAIRE

    Somnhot, Parina

    2012-01-01

    Lithium-ion batteries possess high energy and power densities, making them ideal candidates for energy storage requirements in various military applications. Commercially produced lithium-ion battery anodes are commonly graphitic carbon-based. However, graphitic carbons are limited in surface area and possess slow intercalation kinetics. The energy and power density demands of future technologies require improved lithium-ion battery performance. Carbon nanomaterials, such as carbide-derived c...

  20. Synthesis of Multiwalled Carbon Nanotubes-Titania Nanomaterial for Desulfurization of Model Fuel

    Directory of Open Access Journals (Sweden)

    Tawfik A. Saleh

    2014-01-01

    Full Text Available This work reported on the development of novel nanomaterials of multiwalled carbon nanotubes doped with titania (CNT/TiO2 for the adsorptive desulfurization of model fuel oils. Various analytical techniques such as field emission scanning electron microscope (FESEM, energy dispersive X-ray spectroscopy (EDX, and Fourier transform infrared spectroscopy (FTIR were used for the characterization of the nanomaterials. The initial results indicated the effectiveness of the prepared CNT/TiO2 nanomaterials in removing sulfur compounds from model fuel oil. The adsorption of DBT, BT, and thiophene from model fuel onto the derived sorbents was performed using batch mode system. These CNT/TiO2 nanomaterials initially afforded approximately 45% removal of DBT, 55% BT, and more than 65% thiophene compounds from model fuels. The CNT/TiO2 nanomaterials provided an excellent activity towards interaction with organosulfur compounds. More experiments are underway to optimize the parameters for the adsorptive desulfurization processes. We believe that these nanomaterials as adsorbents will find useful applications in petroleum industry because of their operational simplicity, high efficiency, and high capacity.

  1. Thermal energy harvesting and solar energy conversion utilizing carbon-based nanomaterials

    Science.gov (United States)

    McCarthy, Patrick T.

    This dissertation provides details of carbon-based nanomaterial fabrication for applications in energy harvesting and generation. As energy demands increase, and concerns about mankind's environmental impact increase, alternative methods of generating energy will be widely researched. Carbon-based nanomaterials may be effective in such applications as their fabrication is often inexpensive and they have highly desirable electrical, mechanical, and thermal properties. Synthesis and characterization of carbon nanotube thermal interfaces on gadolinium foils is described herein. Total thermal interface resistances of carbon nanotube coated gadolinium were measured using a one-dimensional reference calorimeter technique, and the effect of hydrogen embrittlement on the magnetic properties of gadolinium foils is discussed. The samples generated in this study were consistently measured with reduced total thermal interface resistances of 55-70% compared to bare gadolinium. Characterization of gadolinium foils in a cooling device called a magneto thermoelectric generator was also performed. A gadolinium shuttle drives the device as it transitions between ferromagnetic and paramagnetic states. Reduced interface resistances from the carbon nanotube arrays led to increased shuttle frequency and effective heat transfer coefficients. Detailed theoretical derivations for electron emission during thermal and photo-excitation are provided for both three-dimensional and two-dimensional materials. The derived theories were fitted to experimental data from variable temperature photoemission studies of potassium-intercalated graphitic nanopetals. A work function reduction from approximately 4.5 eV to 2 -- 3 eV resulted from potassium intercalation and adsorption. While changes in the electron energy distribution shape and intensity were significant within 310 -- 680 K, potassium-intercalated graphitic petals demonstrate very high thermal stability after heating to nearly 1000 K. Boron

  2. High performance ultracapacitors with carbon nanomaterials and ionic liquids

    Science.gov (United States)

    Lu, Wen; Henry, Kent Douglas

    2012-10-09

    The present invention is directed to the use of carbon nanotubes and/or electrolyte structures in various electrochemical devices, such as ultracapacitors having an ionic liquid electrolyte. The carbon nanotubes are preferably aligned carbon nanotubes. Compared to randomly entangled carbon nanotubes, aligned carbon nanotubes can have better defined pore structures and higher specific surface areas.

  3. 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...

  4. Effect of carbon black nanomaterial on biological membranes revealed by shape of human erythrocytes, platelets and phospholipid vesicles

    OpenAIRE

    Drašler, Barbara; Pajnič, Manca; Šuštar, Vid; Štukelj, Roman; Kononenko, Veno; Šimundić, Metka; Hägerstrand, Henry; Kralj-Iglič, Veronika; Makovec, Darko; Drobne, Damjana; Krek, Judita Lea

    2016-01-01

    Background We studied the effect of carbon black (CB) agglomerated nanomaterial on biological membranes as revealed by shapes of human erythrocytes, platelets and giant phospholipid vesicles. Diluted human blood was incubated with CB nanomaterial and observed by different microscopic techniques. Giant unilamellar phospholipid vesicles (GUVs) created by electroformation were incubated with CB nanomaterial and observed by optical microscopy. Populations of erythrocytes and GUVs were analyzed: t...

  5. Volatile-nanoparticle-assisted optical visualization of individual carbon nanotubes and other nanomaterials

    Science.gov (United States)

    Jian, Muqiang; Xie, Huanhuan; Wang, Qi; Xia, Kailun; Yin, Zhe; Zhang, Mingyu; Deng, Ningqin; Wang, Luning; Ren, Tianling; Zhang, Yingying

    2016-07-01

    The development of nanomaterials has put forward high requirements for characterization techniques. Optical microscopy (OM), with easy accessibility and open operating spaces as compared to scanning electron microscopy, is a good choice to quickly locate materials and to be integrated with other equipment. However, OM is limited by its low resolution. Herein, we present a facile and non-destructive approach for optical observation of nanomaterials under conventional OMs with the aid of volatile nanoparticles (NPs), which can be deposited and removed in a controlled manner. The NPs deposited on the surface of nanomaterials render strong light scattering to enable the nanomaterials to become optically visible. For example, this approach enables the observation of individual carbon nanotubes (CNTs) with OMs at low magnification or even with the naked eye. Both supported CNTs on various substrates and suspended CNTs can be observed with this approach. Most importantly, the NPs can be completely removed through moderate heat treatment or laser irradiation, avoiding potential influence on the properties or subsequent applications of nanomaterials. Furthermore, we systematically investigate the deposition of various volatile NPs (up to 14 kinds) for the optical observation of nanomaterials. We also demonstrated the application of this approach on other nanomaterials, including nanowires and graphene. We showed that this approach is facile, controllable, non-destructive, and contamination-free, indicating wide potential applications.The development of nanomaterials has put forward high requirements for characterization techniques. Optical microscopy (OM), with easy accessibility and open operating spaces as compared to scanning electron microscopy, is a good choice to quickly locate materials and to be integrated with other equipment. However, OM is limited by its low resolution. Herein, we present a facile and non-destructive approach for optical observation of

  6. Synthesis of the Carbon Nanomaterials Based on Renewable Bioresources

    Directory of Open Access Journals (Sweden)

    N.A. Chan

    2014-07-01

    Full Text Available The effectiveness and feasibility of producing nanoscale carbon materials from renewable bioresources were shown as an example marsh mass. The mechanisms of synthesis of amorphous organic carbon from sphagnum moss species modified by a liquid peat phase of humic nature are discussed. A fundamentally new way of producing carbon nanotubes by mechanical activation of amorphous organic carbon is described.

  7. Chains of carbon atoms: A vision or a new nanomaterial?

    Directory of Open Access Journals (Sweden)

    Florian Banhart

    2015-02-01

    Full Text Available Linear strings of sp1-hybridized carbon atoms are considered as a possible phase of carbon since decades. Whereas the debate about the stability of the corresponding bulk phase carbyne continues until today, the existence of isolated chains of carbon atoms has meanwhile been corroborated experimentally. Since graphene, as the two-dimensional sp2-bonded allotrope of carbon, has become a vast field, the question about the importance of one-dimensional carbon became of renewed interest. The present article gives an overview of the work that has been carried out on chains of carbon atoms in the past one or two decades. The review concentrates on isolated chains of carbon atoms and summarizes the experimental observations to date. While the experimental information is still very limited, many calculations of the physical and chemical properties have been published in the past years. Some of the most important theoretical studies and their importance in the present experimental situation are reviewed.

  8. MALDI matrices for biomolecular analysis based on functionalized carbon nanomaterials.

    Science.gov (United States)

    Ugarov, Michael V; Egan, T; Khabashesku, Dmitry V; Schultz, J Albert; Peng, Haiqing; Khabashesku, Valery N; Furutani, Hiroshi; Prather, Kimberley S; Wang, H-W J; Jackson, S N; Woods, Amina S

    2004-11-15

    When used in small molar ratios of matrix to analyte, derivatized fullerenes and single wall nanotubes are shown to be efficient matrices for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The mixing of an acidic functionalized fullerene with a solution of bioanalyte, depositing a dried droplet, and irradiating with a pulsed nitrogen laser yields protonated or cationized molecular ions. Derivatized fullerenes could offer several advantages over conventional MALDI matrices: a high analyte ionization efficiency, a small molar ratios (less than 1) of matrix/analyte, and a broader optical absorption spectrum, which should obviate specific wavelength lasers for MALDI acquisitions. The major disadvantage to the use of fullerenes is the isobaric interference between matrix and analyte ions; however, it is overcome by using MALDI-ion mobility time-of-flight (IM-oTOF) mass spectrometry to preseparate carbon cluster ions from bioanalyte ions prior to TOF mass analysis. However, an alternative to the dried droplet preparation of fullerene MALDI samples is the aerosolization of matrix-analyte solutions (or slurries) followed by impacting the aerosol onto a stainless surface. We also demonstrate that the fullerene matrices can be used to acquire spectra from rat brain tissue. PMID:15538798

  9. 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

  10. Influence of electrical stress on printed polymer resistors filled with carbon nanomaterials

    Science.gov (United States)

    Słoma, Marcin; Jakubowska, Małgorzata; Szałatkiewicz, Jakub

    2013-10-01

    Superior electrical properties of carbon nanotubes were utilized by the authors in the fabrication of printed resistors. In common applications such as electrodes or sensors, only basic electrical and mechanical properties are investigated, leaving aside other key parameters related to the stability and reliability of particular elements. In this paper we present experimental results on the properties of printed resistive layers. One of the most important issues is their stability under high currents creating excessive thermal stresses. In order to investigate such behavior, a high direct current stress test was performed along with the observation of temperature distribution that allowed us to gain a fundamental insight into the electrical behavior at such operating conditions. These experiments allowed us to observe parametric failure or catastrophic damage that occurred under excessive supply parameters. Electrical parameters of all investigated samples remained stable after applying currents inducing an increase in temperature up to 130 °C and 200 °C. For selected samples, catastrophic failure was observed at the current values inducing temperature above 220 °C and 300 °C but in all cases the failure was related to the damage of PET or alumina substrate. Additional experiments were carried out with short high voltage pulse stresses. Printed resistors filled with nanomaterials sustained similar voltage levels (up to 750 V) without changing their parameters, while commonly used graphite filled polymer resistors changed their resistance value.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Preparation and characterization of nanomaterials based on bifacial carbon nanotubes and iron oxides: Application in catalysis

    Directory of Open Access Journals (Sweden)

    Zafour-Hadj-Ziane A.

    2013-09-01

    Full Text Available The application of magnetic particles technology for the development of new nanomaterials has received considerable attention in recent years. In this context, the objective of this study is firstly, to prepare new catalytic materials that gather the strong adsorption capacities of carbon nanotubes and magnetic properties of iron, it concerns nanocomposites based on a mixture of carbon nanotubes in a very small amounts and iron oxide. Secondly we want to appear their capacities in catalytic oxidation reactions of phenol. Synthesis under the optimal conditions was carried out at different pH. And the characterization of this new nanomaterial reveals a good specific surface area BET, the identification of carbon nanotubes within the matrix was performed by infrared spectroscopy and transmission electron microscopy. The use of this new material as a catalytic support in catalytic oxidation reactions of phenol indicates the high selectivity of this latter and a yield better than this obtained with iron oxide supported by activated carbon. The good catalyst regeneration of the new catalysis and the improvement in their properties are the interesting parameters for the new type nanomaterials.

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

    OpenAIRE

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

    2016-01-01

    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...

  15. 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)

  16. Hybrid carbon nanomaterials for electrochemical detection of biomolecules

    Science.gov (United States)

    Laurila, Tomi

    2015-09-01

    Electrochemical detection of different biomolecules in vivo is a promising path towards in situ monitoring of human body and its functions. However, there are several major obstacles, such as sensitivity, selectivity and biocompatiblity, which must be tackled in order to achieve reliably and safely operating sensor devices. Here we show that by utilizing hybrid carbon materials as electrodes to detect two types of neurotransmitters, dopamine and glutamate, several advantages over commonly used electrode materials can be achieved. In particular, we will demonstrate here that it is possible to combine the properties of different carbon allotropes to obtain hybrid materials with greatly improved electrochemical performance. Three following examples of the approach are given: (i) diamond-like carbon (DLC) thin film electrodes with different layer thicknesses, (ii) multi-walled carbon nanotubes grown directly on top of DLC and (iii) carbon nanofibres synthesized on top of DLC thin films. Detailed structural and electrochemical characterization is carried out to rationalize the reasons behind the observed behvior. In addition, results from the atomistic simulations are utilized to obtain more information about the properties of the amorphous carbon thin films.

  17. 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.

  18. Effect of the morphology of structured carbon nanomaterials on their oxidizability

    Science.gov (United States)

    Savilov, S. V.; Ivanov, A. S.; Egorov, A. V.; Kirikova, M. N.; Arkhipova, E. A.; Lunin, V. V.

    2016-02-01

    The oxidation of multi-walled carbon nanotubes (MCNTs), nanofibers (CNFs), and few-layer graphite fragments (FLGFs) with a nitric acid solution was studied. The oxygen content in the functionalized derivatives was determined by X-ray photoelectron spectroscopy and thermal analysis. The results were correlated with the structural features of the nanomaterials revealed by high-resolution transmission electron microscopy and X-ray diffraction. The highest content of carboxyl groups was achieved by functionalization of carbon nanotubes with the conical position of graphene layers.

  19. Discharge characteristics in liquid helium, liquid nitrogen and pure water preparatory to fabrication of carbon nanomaterials

    International Nuclear Information System (INIS)

    Discharge characteristics and emission spectra of the discharges in low-temperature liquid such as liquid helium have been measured to investigate the conditions for fabrication of carbon nanomaterial by arc discharge in low-temperature liquid. Measurements of the discharge characteristics of the resulting plasma and observation of the associated optical emission spectra show that the behaviour of discharge current over time and the associated spectra depend strongly on discharge voltage and both may be related to the temperature of the carbon target. However, discharge voltage and current with time are almost the same regardless of whether the liquid is pure water, liquid nitrogen, liquid helium and superfluid liquid helium

  20. Carbon nanomaterials from pyrolysis of polydiacetylene-walled nanorods

    International Nuclear Information System (INIS)

    Pyrolysis of polydiacetylene-walled nanorods obtained from a rigid and shape-persistent macrocyclic precursor was performed. The thermogravimetric analysis showed that pyrolysis caused a loss of aliphatic chains and structural changes of PDAs to produce carbon-rich nanoarchitectures, as confirmed by Raman and UV-visible spectroscopy. The transmission electron microscopy imaging performed on the resulting material showed the formation of an entangled nanofibrils network containing various types of nanostructures. (papers)

  1. Carbon nanomaterial-based electrochemical biosensors for label-free sensing of environmental pollutants.

    Science.gov (United States)

    Ramnani, Pankaj; Saucedo, Nuvia M; Mulchandani, Ashok

    2016-01-01

    Carbon allotropes such as graphene and carbon nanotubes, have been incorporated in electrochemical biosensors for highly sensitive and selective detection of various analytes. The superior physical and electrical properties like high carrier mobility, ambipolar electric field effect, high surface area, flexibility and their compatibility with microfabrication techniques makes these carbon nanomaterials easy to integrate in field-effect transistor (FET)/chemiresistor type configuration which is suitable for portable and point-of-use/field-deployable sensors. This review covers the synthesis of carbon nanostructures (graphene and CNTs) and their integration into devices using various fabrication methods. Finally, we discuss the recent reports showing different sensing platforms that incorporate biomolecules like enzymes, antibodies and aptamers as recognition elements for fabrication of simple, low cost, compact biosensors that can be used for on-site, rapid environmental monitoring of environmental pollutants like pathogens, heavy metals, pesticides and explosives.

  2. Carbon nanomaterial-based electrochemical biosensors for label-free sensing of environmental pollutants.

    Science.gov (United States)

    Ramnani, Pankaj; Saucedo, Nuvia M; Mulchandani, Ashok

    2016-01-01

    Carbon allotropes such as graphene and carbon nanotubes, have been incorporated in electrochemical biosensors for highly sensitive and selective detection of various analytes. The superior physical and electrical properties like high carrier mobility, ambipolar electric field effect, high surface area, flexibility and their compatibility with microfabrication techniques makes these carbon nanomaterials easy to integrate in field-effect transistor (FET)/chemiresistor type configuration which is suitable for portable and point-of-use/field-deployable sensors. This review covers the synthesis of carbon nanostructures (graphene and CNTs) and their integration into devices using various fabrication methods. Finally, we discuss the recent reports showing different sensing platforms that incorporate biomolecules like enzymes, antibodies and aptamers as recognition elements for fabrication of simple, low cost, compact biosensors that can be used for on-site, rapid environmental monitoring of environmental pollutants like pathogens, heavy metals, pesticides and explosives. PMID:25956023

  3. 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. PMID:26925363

  4. 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.

  5. Carbonaceous nanomaterials immobilised mixed matrix membrane microextraction for the determination of polycyclic aromatic hydrocarbons in sewage pond water samples.

    Science.gov (United States)

    Mukhtar, Nurul Hazirah; See, Hong Heng

    2016-08-10

    In this study, the potential for carbonaceous nanomaterials to be used as adsorbents for the mixed matrix membrane (MMM) microextraction and preconcentration of organic pollutants was demonstrated. For this method, multiwall carbon nanotubes (MWCNT) and single layer graphene (SLG) nanoparticles were individually incorporated through dispersion in a cellulose triacetate (CTA) polymer matrix to form a MWCNT-MMM and SLG-MMM, respectively. The prepared membranes were evaluated for the extraction of selected polycyclic aromatic hydrocarbons (PAHs) present in sewage pond water samples. The extraction was performed by dipping a small piece of membrane (7 mm × 7 mm) in a stirred 7.5 mL sample solution to initiate the analyte adsorption. This step was followed by an analyte desorption into 60 μL of methanol prior to high performance liquid chromatography (HPLC) analysis. When the optimum SLG-MMM microextraction technique was applied to spiked sewage pond water samples, the detection limit of the method for the PAHs were in the range of 0.02-0.09 ng/mL, with relative standard deviations of between 1.4% and 7.8%. Enrichment factors of 54-100 were achieved with relative recoveries of 99%-101%. A comparison was also made between the proposed approach and standard solid phase extraction using polymeric bonded octadecyl (C18) cartridges. PMID:27282751

  6. Exposure Assessment and Inflammatory Response Among Workers Producing Calcium Carbonate Nanomaterials

    Science.gov (United States)

    Cui, Ling

    Problem: Nanotechnology is one of the most rapidly growing fields of science and engineering, and its applications have expanded to numerous research and industrial sectors, from consumer products to medicine to energy. Nano-materials and nanotechnology promise substantial benefits. However, there are many uncertainties and concerns regarding human health and the environment. Numerous toxicological studies on animals and cells in vitro have demonstrated that nanomaterials could cause various adverse health effects, including inflammation, oxidative stress, fibrosis and mutagenesis in the lungs, and cardiovascular and nervous system impairment. Objectives: The overall objective of this study was to characterize particulate exposures in a calcium carbonate nanoparticle manufacturing facility, investigate possible respiratory and cardiovascular effects, and explore the plausibility of an inflammatory mechanism. The associations between exposure level and various health outcomes were investigated. Methodology: Each job was characterized by mass, number and surface area concentration. Job classification was performed based on ranking of the exposure level and statistical models. Lung function tests, exhaled NO and blood pressure (BP) were measured before and after the workshift in the year of 2011. Inflammatory cytokines from induced sputum were measured cross-sectionally in the year of 2011. Data of lung function tests and blood pressure were collected cross-sectionally in the year of 2012. The associations between each exposure metric and health measures in 2012 were investigated. Only mass concentration was linked to both 2011 and 2012 health outcomes. Results: The sampling and analytic methodology used in the study presents the potential to characterize nanoparticle exposure for a variety of operational processes. We found the highest mass exposure occurred at bagging job whereas the highest number and surface area concentration was found at modification

  7. Carbon nanotubes: artificial nanomaterials to engineer single neurons and neuronal networks.

    Science.gov (United States)

    Fabbro, Alessandra; Bosi, Susanna; Ballerini, Laura; Prato, Maurizio

    2012-08-15

    In the past decade, nanotechnology applications to the nervous system have often involved the study and the use of novel nanomaterials to improve the diagnosis and therapy of neurological diseases. In the field of nanomedicine, carbon nanotubes are evaluated as promising materials for diverse therapeutic and diagnostic applications. Besides, carbon nanotubes are increasingly employed in basic neuroscience approaches, and they have been used in the design of neuronal interfaces or in that of scaffolds promoting neuronal growth in vitro. Ultimately, carbon nanotubes are thought to hold the potential for the development of innovative neurological implants. In this framework, it is particularly relevant to document the impact of interfacing such materials with nerve cells. Carbon nanotubes were shown, when modified with biologically active compounds or functionalized in order to alter their charge, to affect neurite outgrowth and branching. Notably, purified carbon nanotubes used as scaffolds can promote the formation of nanotube-neuron hybrid networks, able per se to affect neuron integrative abilities, network connectivity, and synaptic plasticity. We focus this review on our work over several years directed to investigate the ability of carbon nanotube platforms in providing a new tool for nongenetic manipulations of neuronal performance and network signaling. PMID:22896805

  8. Carbon nanotubes: artificial nanomaterials to engineer single neurons and neuronal networks.

    Science.gov (United States)

    Fabbro, Alessandra; Bosi, Susanna; Ballerini, Laura; Prato, Maurizio

    2012-08-15

    In the past decade, nanotechnology applications to the nervous system have often involved the study and the use of novel nanomaterials to improve the diagnosis and therapy of neurological diseases. In the field of nanomedicine, carbon nanotubes are evaluated as promising materials for diverse therapeutic and diagnostic applications. Besides, carbon nanotubes are increasingly employed in basic neuroscience approaches, and they have been used in the design of neuronal interfaces or in that of scaffolds promoting neuronal growth in vitro. Ultimately, carbon nanotubes are thought to hold the potential for the development of innovative neurological implants. In this framework, it is particularly relevant to document the impact of interfacing such materials with nerve cells. Carbon nanotubes were shown, when modified with biologically active compounds or functionalized in order to alter their charge, to affect neurite outgrowth and branching. Notably, purified carbon nanotubes used as scaffolds can promote the formation of nanotube-neuron hybrid networks, able per se to affect neuron integrative abilities, network connectivity, and synaptic plasticity. We focus this review on our work over several years directed to investigate the ability of carbon nanotube platforms in providing a new tool for nongenetic manipulations of neuronal performance and network signaling.

  9. Influence of oxygen concentration, fuel composition, and strain rate on synthesis of carbon nanomaterials

    International Nuclear Information System (INIS)

    This paper investigates the influence of flame parameters including oxygen concentration, fuel composition, and strain rate on the synthesis of carbon nanomaterials in opposed-jet ethylene diffusion flames with or without rigid-body rotation. In the experiments, a mixture of ethylene and nitrogen was introduced from the upper burner; meanwhile, a mixture of oxygen and nitrogen was supplied from the lower burner. A nascent nickel mesh was used as the catalytic metal substrate to collect deposited materials. With non-rotating opposed-jet diffusion flames, carbon nanotubes (CNTs) were successfully produced for oxygen concentrations in the range of 21–50 % at a fixed ethylene concentration of 20 %, and for ethylene concentrations ranging from 14 to 24 % at a constant oxygen concentration of 40 %. With rotating opposed-jet diffusion flames, the strain rate was varied by adjusting the angular velocities of the upper and lower burners. The strain rate governed by flow rotation greatly affects the synthesis of carbon nanomaterials [i.e., CNTs and carbon nano-onions (CNOs)] either through the residence time or carbon sources available. An increase in the angular velocity lengthened the residence time of the flow and thus caused the diffusion flame to experience a decreased strain rate, which in turn produced more carbon sources. The growth of multi-walled CNTs was achieved for the stretched flames experiencing a higher strain rate [i.e., angular velocity was equal to 0 or 1 rotations per second (rps)]. CNOs were synthesized at a lower strain rate (i.e., angular velocity was in the range of 2–5 rps). It is noteworthy that the strain rate controlled by flow rotation greatly influences the fabrication of carbon nanostructures owing to the residence time as well as carbon source. Additionally, more carbon sources and higher temperature are required for the synthesis of CNOs compared with those required for CNTs (i.e., about 605–625 °C for CNTs and 700–800 °C for

  10. Autochthonous self-assembly of nature's nanomaterials: green, parsimonious and antibacterial carbon nanofilms on glass.

    Science.gov (United States)

    Gopal, Judy; Muthu, Manikandan; Chun, Sechul

    2016-07-28

    The development of thin film coatings has been a very important development in materials science for the modification of native material surface properties. Thin film coatings are enabled through the use of sophisticated instruments and technologies that demand expertise and huge initial and running costs. Nano-thin films are yet a furtherance of thin films which require more expertise and much more sophistication. In this work for the first time we present a one-pot straightforward carbon thin film coating methodology for glass substrates. There is novelty in every single aspect of the method, with the carbon used in the nanofilm being obtained from turmeric soot, the coating technique consisting of a basic immersion technique, a dip-dry method, in combination with the phytosoot-derived carbon's inherent ability to self-assemble to form a uniform and continuous stable coating. The carbon nanofilm has been characterized using field emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDAX) analysis, a goniometer and X-ray diffraction (XRD). This study for the first time opens a new school of thought of using such naturally available free nanomaterials as eco-friendly green coatings. The amorphous porous carbon film can be coated on any hydrophilic substrate and is not substrate specific. Its added advantages of being transparent and antibacterial in spite of being green and parsimonious are meant to realize its utility as ideal choices for solar panels, medical implants and other construction applications.

  11. Autochthonous self-assembly of nature's nanomaterials: green, parsimonious and antibacterial carbon nanofilms on glass.

    Science.gov (United States)

    Gopal, Judy; Muthu, Manikandan; Chun, Sechul

    2016-07-28

    The development of thin film coatings has been a very important development in materials science for the modification of native material surface properties. Thin film coatings are enabled through the use of sophisticated instruments and technologies that demand expertise and huge initial and running costs. Nano-thin films are yet a furtherance of thin films which require more expertise and much more sophistication. In this work for the first time we present a one-pot straightforward carbon thin film coating methodology for glass substrates. There is novelty in every single aspect of the method, with the carbon used in the nanofilm being obtained from turmeric soot, the coating technique consisting of a basic immersion technique, a dip-dry method, in combination with the phytosoot-derived carbon's inherent ability to self-assemble to form a uniform and continuous stable coating. The carbon nanofilm has been characterized using field emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDAX) analysis, a goniometer and X-ray diffraction (XRD). This study for the first time opens a new school of thought of using such naturally available free nanomaterials as eco-friendly green coatings. The amorphous porous carbon film can be coated on any hydrophilic substrate and is not substrate specific. Its added advantages of being transparent and antibacterial in spite of being green and parsimonious are meant to realize its utility as ideal choices for solar panels, medical implants and other construction applications. PMID:27355696

  12. Tomato Seed Coat Permeability to Selected Carbon Nanomaterials and Enhancement of Germination and Seedling Growth.

    Science.gov (United States)

    Ratnikova, Tatsiana A; Podila, Ramakrishna; Rao, Apparao M; Taylor, Alan G

    2015-01-01

    Seed coat permeability was examined using a model that tested the effects of soaking tomato (Solanum lycopersicon) seeds in combination with carbon-based nanomaterials (CBNMs) and ultrasonic irradiation (US). Penetration of seed coats to the embryo by CBNMs, as well as CBNMs effects on seed germination and seedling growth, was examined. Two CBNMs, C60(OH)20 (fullerol) and multiwalled nanotubes (MWNTs), were applied at 50 mg/L, and treatment exposure ranged from 0 to 60 minutes. Bright field, fluorescence, and electron microscopy and micro-Raman spectroscopy provided corroborating evidence that neither CBNM was able to penetrate the seed coat. The restriction of nanomaterial (NM) uptake was attributed to the semipermeable layer located at the innermost layer of the seed coat adjacent to the endosperm. Seed treatments using US at 30 or 60 minutes in the presence of MWNTs physically disrupted the seed coat; however, the integrity of the semipermeable layer was not impaired. The germination percentage and seedling length and weight were enhanced in the presence of MWNTs but were not altered by C60(OH)20. The combined exposure of seeds to NMs and US provided insight into the nanoparticle-seed interaction and may serve as a delivery system for enhancing seed germination and early seedling growth.

  13. Evidence of double layer/capacitive charging in carbon nanomaterial-based solid contact polymeric ion-selective electrodes.

    Science.gov (United States)

    Cuartero, Maria; Bishop, Josiah; Walker, Raymart; Acres, Robert G; Bakker, Eric; De Marco, Roland; Crespo, Gaston A

    2016-08-11

    This paper presents the first direct spectroscopic evidence for double layer or capacitive charging of carbon nanomaterial-based solid contacts in all-solid-state polymeric ion-selective electrodes (ISEs). Here, we used synchrotron radiation-X-ray photoelectron spectroscopy (SR-XPS) and SR valence band (VB) spectroscopy in the elucidation of the charging mechanism of the SCs.

  14. Evidence of double layer/capacitive charging in carbon nanomaterial-based solid contact polymeric ion-selective electrodes.

    Science.gov (United States)

    Cuartero, Maria; Bishop, Josiah; Walker, Raymart; Acres, Robert G; Bakker, Eric; De Marco, Roland; Crespo, Gaston A

    2016-08-11

    This paper presents the first direct spectroscopic evidence for double layer or capacitive charging of carbon nanomaterial-based solid contacts in all-solid-state polymeric ion-selective electrodes (ISEs). Here, we used synchrotron radiation-X-ray photoelectron spectroscopy (SR-XPS) and SR valence band (VB) spectroscopy in the elucidation of the charging mechanism of the SCs. PMID:27405722

  15. Aqueous dispersions of oligomer-grafted carbon nanomaterials with controlled surface charge and minimal framework damage

    Science.gov (United States)

    Hu, Sheng; Chen, Shu; Menzel, Robert; Goode, Angela D.; Ryan, Mary P.; Porter, Alexandra E.; Shaffer, Milo S. P.

    2015-01-01

    Functionalised carbon nanomaterials (CNMs), with an undamaged carbon framework and controlled physiochemical properties, are desirable for a wide range of scientific studies and commercial applications. The use of a thermochemical grafting approach provides a versatile means to functionalise both multi-walled carbon nanotubes (MWCNTs) and carbon black (CB) nanoparticles without altering their inherent structure. The functionalisation process was investigated by employing various types of grafting monomers; to improve water solubility, reagents were chosen that introduced ionic character either intrinsically or after further chemical reaction. The degree of grafting for both MWCNTs and CB ranged from 3 to 27 wt%, as established by thermal gravimetric analysis (TGA). Raman spectroscopy confirmed that the structural framework of the MWNTs was unaffected by the thermochemical treatment. The effectiveness of the surface modification was demonstrated by significantly improved dispersibility and stability in water, and further quantified by zeta-potential analysis. The concentration of stable, individualised, grafted MWNTs in water ranged from 30 to 80 µg mL−1, whereas functionalised CB (CB) in water showed improved dispersibility up to ~460 µg mL−1 after centrifugation at 10, 000 g for 15 minutes. The successful preparation of structurally identical but differently functionalised nanoparticles panels, with high water compatibility and minimal framework damage, are useful for controlled experiments. For example, they can be used to explore the relationship between toxicological effects and specific physiochemical properties, such as surface charge and geometry. PMID:25254653

  16. Carbon nanomaterials in clean and contaminated soils: environmental implications and applications

    Science.gov (United States)

    Riding, M. J.; Martin, F. L.; Jones, K. C.; Semple, K. T.

    2015-01-01

    The exceptional sorptive ability of carbon nanomaterials (CNMs) for hydrophobic organic contaminants (HOCs) is driven by their characteristically large reactive surface areas and highly hydrophobic nature. Given these properties, it is possible for CNMs to impact on the persistence, mobility and bioavailability of contaminants within soils, either favourably through sorption and sequestration, hence reducing their bioavailability, or unfavourably through increasing contaminant dispersal. This review considers the complex and dynamic nature of both soil and CNM physicochemical properties to determine their fate and behaviour, together with their interaction with contaminants and the soil microflora. It is argued that assessment of CNMs within soil should be conducted on a case-by-case basis and further work to assess the long-term stability and toxicity of sorbed contaminants, as well as the toxicity of CNMs themselves, is required before their sorptive abilities can be applied to remedy environmental issues.

  17. A Microbial Fuel Cell Modified with Carbon Nanomaterials for Organic Removal and Denitrification

    Directory of Open Access Journals (Sweden)

    Njud S. Alharbi

    2013-01-01

    Full Text Available This paper investigated microbial denitrification using electrochemical sources to replace organic matter as reductant. The work also involved developing a system that could be optimised for nitrate removal in applied situations such as water processing in fish farming or drinking water, where high nitrate levels represent a potential health problem. Consequently, the study examined a range of developments for the removal of nitrate from water based on the development of electrochemical biotransformation systems for nitrate removal. This also offers considerable scope for the potential application of these systems in broader bionanotechnology based processes. Furthermore, the work discussed the context of improved microbial fuel cell (MFC performance, potential analytic applications, and further innovations using a bionanotechnology approach to analyse cell-electrode interactions. High nitrate removal rate of more than 95% was successfully achieved by using a MFC system modified with carbon nanomaterials.

  18. THE INFLUENCE OF THE COMPLEX CHEMICAL ADDITIVE CONTAINING THE STRUCTURED CARBON NANOMATERIAL ON PROPERTIES OF CEMENT

    Directory of Open Access Journals (Sweden)

    O. Yu. Sheyda

    2015-01-01

    Full Text Available The paper presents results of investigations on influence of domestic complex chemical additive containing structured carbon nanomaterial and characterized by a combination effect (curing acceleration and plasticizing on cement and cement stone properties. The purpose of the investigations, on the one hand, has been to confirm efficacy of УКД-1additive from the perspective for increasing the rate of gain, strength growth of cement concrete and additive influence on setting time with the purpose to preserve molding properties of concrete mixes in time, and on the other hand, that is to assess “mechanism” of the УКД-1 additive action in the cement concrete. The research results have revealed regularities in changes due to the additive of water requirements and time period of the cement setting. The reqularities are considered as a pre-requisite for relevant changes in molding properties of the concrete mixes. The paper also experimentally substantiates the possibility to decrease temperature of cement concrete heating with the УДК-1 additive. It has been done with the purpose to save energy resources under production conditions. In addition to this the paper proves the efficiency of the additive which is expressed in strength increase of cement stone up to 20–40 % in the rated age (28 days that is considered as a basis for strength growth of cement concrete. The paper confirms a hypothesis on physical nature of this phenomenon because the X-ray phase analysis method has shown that there are no changes in morphology of portland cement hydration products under the action of the additive agent containing a structured carbon nanomaterial. Results of theoretical and experimental investigations on УКД-1 additive efficiency have been proved by industrial approbation while fabricating precast concrete products and construction of monolithic structures under plant industrial conditions (Minsk, SS “Stroyprogress” JSC MAPID and on

  19. Detection and characterization of nanomaterials released in low concentrations during multi-walled carbon nanotube spraying process in a cleanroom.

    Science.gov (United States)

    Ji, Jun Ho; Woo, Daekwang; Lee, Seung-Bok; Kim, Taesung; Kim, Duckjong; Kim, Jae-Hyun; Bae, Gwi-Nam

    2013-12-01

    Release of nanomaterials was assessed in a cleanroom workplace designed for the handling of multi-walled carbon nanotubes. During the process, the nanotubes were sprayed in a chamber fitted with an exhaust duct system. The front door of the spraying chamber was completely closed, but rear end of the chamber was partially open. Throughout a series of spray processes, three detectors - an optical particle counter, a nanoparticle aerosol monitor, and an aethalometer - counted and characterized particles escaping the chamber. Concentrations of particle surface area and black carbon emitted by the spraying were assessed assuming zero background aerosol concentration in the cleanroom. Very low concentrations of black carbon, 0.4 μg/m(3), were observed. In conclusion, in a cleanroom, low concentrations of nanomaterials were detected to be emitted from a spraying chamber into the workplace. The level of particles reaching the workplace was sufficiently low to have made their detection difficult in a normal environment. Both target nanomaterial and non-intended incidental nanomaterials were released during spraying. Despite the use of exhaust duct system in the process chamber, workers would be exposed to some particles if the chamber were partially open. The exhaust duct system was not enough to remove all the particles released in the chamber.

  20. A Review on Nanomaterial Dispersion, Microstructure, and Mechanical Properties of Carbon Nanotube and Nanofiber Reinforced Cementitious Composites

    Directory of Open Access Journals (Sweden)

    Shama Parveen

    2013-01-01

    Full Text Available Excellent mechanical, thermal, and electrical properties of carbon nanotubes (CNTs and nanofibers (CNFs have motivated the development of advanced nanocomposites with outstanding and multifunctional properties. After achieving a considerable success in utilizing these unique materials in various polymeric matrices, recently tremendous interest is also being noticed on developing CNT and CNF reinforced cement-based composites. However, the problems related to nanomaterial dispersion also exist in case of cementitious composites, impairing successful transfer of nanomaterials' properties into the composites. Performance of cementitious composites also depends on their microstructure which is again strongly influenced by the presence of nanomaterials. In this context, the present paper reports a critical review of recent literature on the various strategies for dispersing CNTs and CNFs within cementitious matrices and the microstructure and mechanical properties of resulting nanocomposites.

  1. Effects of freeze drying and silver staining on carbonization of cellulose: carbon nano-materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae-Young; Im, Hyun Sik [Dongguk University, Seoul (Korea, Republic of)

    2012-05-15

    We investigated the effects of sulfuric acid and silver particles on the carbonization of natural cellulose from Halocynthia. We carried out thermogravimetry and used transmission electron microscopy measurements to study the yield of carbon and the structure of the carbonized nano-fiber. We found that the addition of sulfuric acid and silver particles to the cellulose fiber enhanced the yield of carbon while keeping the original structure of the carbon nano-fiber.

  2. 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.

  3. 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.

  4. 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)

    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

  5. Comparative study of plant responses to carbon-based nanomaterials with different morphologies.

    Science.gov (United States)

    Lahiani, Mohamed H; Dervishi, Enkeleda; Ivanov, Ilia; Chen, Jihua; Khodakovskaya, Mariya

    2016-07-01

    The relationship between the morphology of carbon-based nanomaterials (CBNs) and the specific response of plants exposed to CBNs has not been studied systematically. Here, we prove that CBNs with different morphologies can activate cell growth, germination, and plant growth. A tobacco cell culture growth was found to increase by 22%-46% when CBNs such as helical multi-wall carbon nanotubes (MWCNTs), few-layered graphene, long MWCNTs, and short MWCNTs were added to the growth medium at a concentration of 50 μg ml(-1). The germination of exposed tomato seeds, as well as the growth of exposed tomato seedlings, were significantly enhanced by the addition of all tested CBNs. The presence of CBNs inside exposed seeds was confirmed by transmission electron microscopy and Raman spectroscopy. The effects of helical MWCNTs on gene expression in tomato seeds and seedlings were investigated by microarray technology and real time-PCR. Helical MWCNTs affected a number of genes involved in cellular and metabolic processes and response to stress factors. It was shown that the expression of the tomato water channel gene in tomato seeds exposed to helical MWCNTs was upregulated. These established findings demonstrate that CBNs with different morphologies can cause the same biological effects and share similar mechanisms in planta. PMID:27195934

  6. Comparative study of plant responses to carbon-based nanomaterials with different morphologies

    Science.gov (United States)

    Lahiani, Mohamed H.; Dervishi, Enkeleda; Ivanov, Ilia; Chen, Jihua; Khodakovskaya, Mariya

    2016-07-01

    The relationship between the morphology of carbon-based nanomaterials (CBNs) and the specific response of plants exposed to CBNs has not been studied systematically. Here, we prove that CBNs with different morphologies can activate cell growth, germination, and plant growth. A tobacco cell culture growth was found to increase by 22%–46% when CBNs such as helical multi-wall carbon nanotubes (MWCNTs), few-layered graphene, long MWCNTs, and short MWCNTs were added to the growth medium at a concentration of 50 μg ml‑1. The germination of exposed tomato seeds, as well as the growth of exposed tomato seedlings, were significantly enhanced by the addition of all tested CBNs. The presence of CBNs inside exposed seeds was confirmed by transmission electron microscopy and Raman spectroscopy. The effects of helical MWCNTs on gene expression in tomato seeds and seedlings were investigated by microarray technology and real time-PCR. Helical MWCNTs affected a number of genes involved in cellular and metabolic processes and response to stress factors. It was shown that the expression of the tomato water channel gene in tomato seeds exposed to helical MWCNTs was upregulated. These established findings demonstrate that CBNs with different morphologies can cause the same biological effects and share similar mechanisms in planta.

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

    Science.gov (United States)

    Edzatty, A. N.; Syazwan, S. M.; Norzilah, A. H.; Jamaludin, S. B.

    2016-07-01

    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.

  8. 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.

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

    International Nuclear Information System (INIS)

    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/m3. 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/cm3 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

  10. 1D/2D Carbon Nanomaterial-Polymer Dielectric Composites with High Permittivity for Power Energy Storage Applications.

    Science.gov (United States)

    Dang, Zhi-Min; Zheng, Ming-Sheng; Zha, Jun-Wei

    2016-04-01

    With the development of flexible electronic devices and large-scale energy storage technologies, functional polymer-matrix nanocomposites with high permittivity (high-k) are attracting more attention due to their ease of processing, flexibility, and low cost. The percolation effect is often used to explain the high-k characteristic of polymer composites when the conducting functional fillers are dispersed into polymers, which gives the polymer composite excellent flexibility due to the very low loading of fillers. Carbon nanotubes (CNTs) and graphene nanosheets (GNs), as one-dimensional (1D) and two-dimensional (2D) carbon nanomaterials respectively, have great potential for realizing flexible high-k dielectric nanocomposites. They are becoming more attractive for many fields, owing to their unique and excellent advantages. The progress in dielectric fields by using 1D/2D carbon nanomaterials as functional fillers in polymer composites is introduced, and the methods and mechanisms for improving dielectric properties, breakdown strength and energy storage density of their dielectric nanocomposites are examined. Achieving a uniform dispersion state of carbon nanomaterials and preventing the development of conductive networks in their polymer composites are the two main issues that still need to be solved in dielectric fields for power energy storage. Recent findings, current problems, and future perspectives are summarized. PMID:26865507

  11. 1D/2D Carbon Nanomaterial-Polymer Dielectric Composites with High Permittivity for Power Energy Storage Applications.

    Science.gov (United States)

    Dang, Zhi-Min; Zheng, Ming-Sheng; Zha, Jun-Wei

    2016-04-01

    With the development of flexible electronic devices and large-scale energy storage technologies, functional polymer-matrix nanocomposites with high permittivity (high-k) are attracting more attention due to their ease of processing, flexibility, and low cost. The percolation effect is often used to explain the high-k characteristic of polymer composites when the conducting functional fillers are dispersed into polymers, which gives the polymer composite excellent flexibility due to the very low loading of fillers. Carbon nanotubes (CNTs) and graphene nanosheets (GNs), as one-dimensional (1D) and two-dimensional (2D) carbon nanomaterials respectively, have great potential for realizing flexible high-k dielectric nanocomposites. They are becoming more attractive for many fields, owing to their unique and excellent advantages. The progress in dielectric fields by using 1D/2D carbon nanomaterials as functional fillers in polymer composites is introduced, and the methods and mechanisms for improving dielectric properties, breakdown strength and energy storage density of their dielectric nanocomposites are examined. Achieving a uniform dispersion state of carbon nanomaterials and preventing the development of conductive networks in their polymer composites are the two main issues that still need to be solved in dielectric fields for power energy storage. Recent findings, current problems, and future perspectives are summarized.

  12. Enhanced Synthesis of Carbon Nanomaterials Using Acoustically Excited Methane Diffusion Flames

    OpenAIRE

    Shuhn-Shyurng Hou; Kuan-Ming Chen; Zong-Yun Yang; Ta-Hui Lin

    2015-01-01

    Acoustically modulated methane jet diffusion flames were used to enhance carbon nanostructure synthesis. A catalytic nickel substrate was employed to collect the deposit materials at sampling position z = 10 mm above the burner exit. The fabrication of carbon nano-onions (CNOs) and carbon nanotubes (CNTs) was significantly enhanced by acoustic excitation at frequencies near the natural flickering frequency (ƒ = 20 Hz) and near the acoustically resonant frequency (ƒ = 90 Hz), respectively. At ...

  13. 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.

  14. 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

    2016-12-01

    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. PMID:27356561

  15. 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.

  16. 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.

  17. Nanomaterial-based approaches for the detection and speciation of mercury.

    Science.gov (United States)

    Xu, Xiaohan; Li, Yu-Feng; Zhao, Jiating; Li, Yunyun; Lin, Jing; Li, Bai; Gao, Yuxi; Chen, Chunying

    2015-12-01

    Mercury is toxic with widespread contamination. Highly sensitive and selective approaches for mercury analysis are desired. Although conventional techniques are accurate and sensitive in the determination of mercury, these procedures are time-consuming, labor-intensive and dependent heavily on expensive instrumentation. In recent years, nanomaterial-based approaches have been proved to be effective alternatives in the detection and speciation of mercury. In this review, the development of different nanomaterial-based approaches was summarized, as well as their utilization for the detection of mercury in environmental and biological samples, such as gold nanomaterials, carbon nanomaterials, quantum dots and so on. Moreover, the speciation of mercury using nanomaterials was also reviewed.

  18. Functionalized carbon nanomaterials: exploring the interactions with Caco-2 cells for potential oral drug delivery

    Directory of Open Access Journals (Sweden)

    Coyuco JC

    2011-10-01

    Full Text Available Jurja C Coyuco, Yuanjie Liu, Bee-Jen Tan, Gigi NC ChiuDepartment of Pharmacy, Faculty of Science, National University of Singapore, SingaporeAbstract: Although carbon nanomaterials (CNMs have been increasingly studied for their biomedical applications, there is limited research on these novel materials for oral drug delivery. As such, this study aimed to explore the potential of CNMs in oral drug delivery, and the objectives were to evaluate CNM cytotoxicity and their abilities to modulate paracellular transport and the P-glycoprotein (P-gp efflux pump. Three types of functionalized CNMs were studied, including polyhydroxy small-gap fullerenes (OH-fullerenes, carboxylic acid functionalized single-walled carbon nanotubes (fSWCNT-COOH and poly(ethylene glycol functionalized single-walled carbon nanotubes (fSWCNT-PEG, using the well-established Caco-2 cell monolayer to represent the intestinal epithelium. All three CNMs had minimum cytotoxicity on Caco-2 cells, as demonstrated through lactose dehydrogenase release and 3-(4,5-dimethyliazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assays. Of the three CNMs, fSWCNT-COOH significantly reduced transepithelial electrical resistance and enhanced transport of Lucifer Yellow across the Caco-2 monolayer. Confocal fluorescence microscopy showed that fSWCNT-COOH treated cells had the highest perturbation in the distribution of ZO-1, a protein marker of tight junction, suggesting that fSWCNT-COOH could enhance paracellular permeability via disruption of tight junctions. This modulating effect of fSWCNT-COOH can be reversed over time. Furthermore, cellular accumulation of the P-gp substrate, rhodamine-123, was significantly increased in cells treated with fSWCNT-COOH, suggestive of P-gp inhibition. Of note, fSWCNT-PEG could increase rhodamine-123 accumulation without modifying the tight junction. Collectively, these results suggest that the functionalized CNMs could be useful as modulators for oral drug

  19. Synthesis of Carbon Nanomaterials-CdSe Composites and Their Photocatalytic Activity for Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Ming-Liang Chen

    2012-01-01

    Full Text Available We use multi-walled carbon nanotube (MWCNT and graphene as carbon nanomaterials to obtain carbon nanomaterilas-CdSe composites using a facile hydrothermal method. The intrinsic characteristics of resulting composites were studied by X-ray diffraction (XRD, Scanning electron microscopy (SEM with energy dispersive X-ray (EDX analysis, transmission electron microscopy (TEM and UV-vis diffuse reflectance spectrophotometer. The as-prepared carbon nanomaterilas-CdSe composites possessed great adsorptivity of dyes, extended light absorption range, and efficient charge separation properties simultaneously. Hence, in the photodegradation of methylene blue, a significant enhancement in the reaction rate was observed with carbon nanomaterilas-CdSe composites, compared to the CdSe compound.

  20. The magnetic and transport properties of template-synthesized carbon-based and related nanomaterials

    Science.gov (United States)

    Friedman, Adam Louis

    The porous alumina template-assisted method of nanoscale materials preparation provides a simple, relatively inexpensive, yet highly controllable and repeatable process for nanomaterial synthesis. Various nanostructures can then be made utilizing the porous structure as a scaffold. In this dissertation we study the porous alumina anodization process, the synthesis of porous alumina-assisted materials, and the basic physical properties of these materials, primarily concentrating on the magnetic and transport properties. First, we study the porous alumina formation process as a function of anodization voltage, acid type, and acid concentration. We find that while acid type strongly affects the growth characteristics of porous alumina, pH does not. We also study the stability of pore formation. We characterize the two- and three-dimensional stability of the growth process. We find that in three dimensions, an unstable formation region as a function of pH and voltage will cause the formation of dendrite structures. Next, we study the synthesis of materials in the porous alumina templates. Through chemical self-assembly, electrodeposition is able to make a wide variety of nanowires and nanotubes and we seek to optimize this process. Third, we study the optical properties Au and Ag nanowire arrays embedded in porous alumina. We find that such materials have use as negative index metamaterials owing to the existence of both transverse and longitudinal surface plasmon resonances. Next, we study the basic magnetic properties of new PAni-ferromagnet composite nanostructures and compare these properties to the magnetic properties of the nanotubes and the nanowires alone. We find the high dielectric properties of the PAni to strongly shield the ferromagnetic nanowires from magnetostatic interactions. Fifth, we make devices out of carbon nanotubes synthesized by CVD in the alumina templates. We investigate the transport properties of these carbon nanotubes. Further, we find

  1. Multi-instrument characterization of five nanodiamond samples: a thorough example of nanomaterial characterization.

    Science.gov (United States)

    Singh, Bhupinder; Smith, Stacey J; Jensen, David S; Jones, Hodge F; Dadson, Andrew E; Farnsworth, Paul B; Vanfleet, Richard; Farrer, Jeffrey K; Linford, Matthew R

    2016-02-01

    Here, we report the most comprehensive characterization of nanodiamonds (NDs) yet undertaken. Five different samples from three different vendors were analyzed by a suite of analytical techniques, including X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), inductively coupled plasma mass spectrometry (ICP-MS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), Brunauer-Emmett-Teller (BET) surface area measurements, and particle size distribution (PSD) measurements. XPS revealed the elemental compositions of the ND surfaces (83-87 at.% carbon and 12-14 at.% oxygen) with varying amounts of nitrogen (0.4-1.8 at.%), silicon (0.1-0.7 at.%), and tungsten (0.3 at.% only in samples from one vendor). ToF-SIMS and ICP showed metal impurities (Al, Fe, Ni, Cr, etc. with unexpectedly high amounts of W in one vendor's samples: ca. 900 ppm). Principal component analyses were performed on the ToF-SIMS and ICP data. DRIFT showed key functional groups (-OH, C=O, C-O, and C=C). BET showed surface areas of 50-214 m(2)/g. XRD and TEM revealed PSD (bimodal distribution and a wide PSD, 5-100 nm, for one vendor's samples). XRD also provided particle sizes (2.7-27 nm) and showed the presence of graphite. EELS gave the sp(2)/sp(3) contents of the materials (37-88% sp(3)). PSD measurements were performed via differential sedimentation of the particles (mean particle size ca. 17-50 nm). This comprehensive understanding should allow for improved construction of nanodiamond-based materials.

  2. Multi-instrument characterization of five nanodiamond samples: a thorough example of nanomaterial characterization.

    Science.gov (United States)

    Singh, Bhupinder; Smith, Stacey J; Jensen, David S; Jones, Hodge F; Dadson, Andrew E; Farnsworth, Paul B; Vanfleet, Richard; Farrer, Jeffrey K; Linford, Matthew R

    2016-02-01

    Here, we report the most comprehensive characterization of nanodiamonds (NDs) yet undertaken. Five different samples from three different vendors were analyzed by a suite of analytical techniques, including X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), inductively coupled plasma mass spectrometry (ICP-MS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), Brunauer-Emmett-Teller (BET) surface area measurements, and particle size distribution (PSD) measurements. XPS revealed the elemental compositions of the ND surfaces (83-87 at.% carbon and 12-14 at.% oxygen) with varying amounts of nitrogen (0.4-1.8 at.%), silicon (0.1-0.7 at.%), and tungsten (0.3 at.% only in samples from one vendor). ToF-SIMS and ICP showed metal impurities (Al, Fe, Ni, Cr, etc. with unexpectedly high amounts of W in one vendor's samples: ca. 900 ppm). Principal component analyses were performed on the ToF-SIMS and ICP data. DRIFT showed key functional groups (-OH, C=O, C-O, and C=C). BET showed surface areas of 50-214 m(2)/g. XRD and TEM revealed PSD (bimodal distribution and a wide PSD, 5-100 nm, for one vendor's samples). XRD also provided particle sizes (2.7-27 nm) and showed the presence of graphite. EELS gave the sp(2)/sp(3) contents of the materials (37-88% sp(3)). PSD measurements were performed via differential sedimentation of the particles (mean particle size ca. 17-50 nm). This comprehensive understanding should allow for improved construction of nanodiamond-based materials. PMID:26700449

  3. Rational design and synthesis of efficient Carbon and/or Silica functional nanomaterials for electrocatalysis and nanomedicine

    Science.gov (United States)

    Da Silva, Rafael

    In nanomaterials there is a strong correlation between structure and properties. Thus, the design and synthesis of nanomaterials with well-defined structures and morphology is essential in order to produce materials with not only unique but also tailorable properties. The unique properties of nanomaterials in turn can be taken advantage of to create materials and nanoscale devices that can help address important societal issues, such as meeting renewable energy sources and efficient therapeutic and diagnostic methods to cure a range of diseases. In this thesis, the different synthetic approaches I have developed to produce functional nanomaterials composed of earth-abundant elements (mainly carbon and silica) at low cost in a very sustainable manner are discussed. In Chapter 1, the fundamental properties of nanomaterials and their properties and potential applications in many areas are introduced. In chapter 2, a novel synthetic method that allows polymerization of polyaniline (PANI), a conducting polymer, inside cylindrical channel pores of nanoporous silica (SBA-15) is discussed. In addition, the properties of the III resulting conducting polymer in the confined nanochannel spaces of SBA-15, and more importantly, experimental demonstration of the use of the resulting hybrid material (PANI/SBA-15 material) as electocatalyst for electrooxidation reactions with good overpotential, close to zero, are detailed. In chapter 3, the synthetic approach discussed in Chapter 2 is further extended to afford nitrogen- and oxygen-doped mesoporous carbons. This is possible by pyrolysis of the PANI/SBA-15 composite materials under inert atmosphere, followed by etching away their silica framework. The high catalytic activity of resulting carbon-based materials towards oxygen reduction reaction despite they do not possess any metal dopants is also included. The potential uses of nanomaterials in areas such as nanomedicine need deep understanding of the biocompatibility/ toxicity of

  4. 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.

  5. Analysis of pulmonary surfactant in rat lungs after inhalation of nanomaterials: Fullerenes, nickel oxide and multi-walled carbon nanotubes.

    Science.gov (United States)

    Kadoya, Chikara; Lee, Byeong-Woo; Ogami, Akira; Oyabu, Takako; Nishi, Ken-ichiro; Yamamoto, Makoto; Todoroki, Motoi; Morimoto, Yasuo; Tanaka, Isamu; Myojo, Toshihiko

    2016-01-01

    The health risks of inhalation exposure to engineered nanomaterials in the workplace are a major concern in recent years, and hazard assessments of these materials are being conducted. The pulmonary surfactant of lung alveoli is the first biological entity to have contact with airborne nanomaterials in inhaled air. In this study, we retrospectively evaluated the pulmonary surfactant components of rat lungs after a 4-week inhalation exposure to three different nanomaterials: fullerenes, nickel oxide (NiO) nanoparticles and multi-walled carbon nanotubes (MWCNT), with similar levels of average aerosol concentration (0.13-0.37 mg/m(3)). Bronchoalveolar lavage fluid (BALF) of the rat lungs stored after previous inhalation studies was analyzed, focusing on total protein and the surfactant components, such as phospholipids and surfactant-specific SP-D (surfactant protein D) and the BALF surface tension, which is affected by SP-B and SP-C. Compared with a control group, significant changes in the BALF surface tension and the concentrations of phospholipids, total protein and SP-D were observed in rats exposed to NiO nanoparticles, but not in those exposed to fullerenes. Surface tension and the levels of surfactant phospholipids and proteins were also significantly different in rats exposed to MWCNTs. The concentrations of phospholipids, total protein and SP-D and BALF surface tension were correlated significantly with the polymorphonuclear neutrophil counts in the BALF. These results suggest that pulmonary surfactant components can be used as measures of lung inflammation. PMID:25950198

  6. 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 ...

  7. Nanomaterial Registry

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Nanomaterial Registry compiles data from multiple databases into a single resource. The goal of this resource is to establish a curated nanomaterial registry,...

  8. Carbon Nanotube Integrative Sampler (CNIS) for passive sampling of nanosilver in the aquatic environment.

    Science.gov (United States)

    Shen, Li; Fischer, Jillian; Martin, Jonathan; Hoque, Md Ehsanul; Telgmann, Lena; Hintelmann, Holger; Metcalfe, Chris D; Yargeau, Viviane

    2016-11-01

    Nanomaterials such as nanosilver (AgNP) can be released into the aquatic environment through production, usage, and disposal. Sensitive and cost-effective methods are needed to monitor AgNPs in the environment. This work is hampered by a lack of sensitive methods to detect nanomaterials in environmental matrixes. The present study focused on the development, calibration and application of a passive sampling technique for detecting AgNPs in aquatic matrixes. A Carbon Nanotube Integrative Sampler (CNIS) was developed using multi-walled carbon nanotubes (CNTs) as the sorbent for accumulating AgNPs and other Ag species from water. Sampling rates were determined in the laboratory for different sampler configurations and in different aquatic matrixes. The sampler was field tested at the Experimental Lakes Area, Canada, in lake water dosed with AgNPs. For a configuration of the CNIS consisting of CNTs bound to carbon fiber (i.e. CNT veil) placed in Chemcatcher® housing, the time weighted average (TWA) concentrations of silver estimated from deployments of the sampler in lake mesocosms dosed with AgNPs were similar to the measured concentrations of "colloidal silver" (i.e. develop on the sampler and could affect the sampling rates. With further development, this novel sampler may provide a simple and sensitive method for screening for the presence of AgNPs in surface waters. PMID:27343941

  9. Analysis of lunar samples for carbon compounds.

    Science.gov (United States)

    Kvenvolden, K. A.

    1971-01-01

    Description of one approach to the analysis for carbon compounds in lunar materials from the Apollo 11 mission. The sequential scheme followed generally accepted organic geochemical practices, but was unusual in its application to a single sample. The procedures of the scheme were designed to minimize handling of the solids and extracts or hydrolysates. The solid lunar sample was retained in all steps of the sequential analysis in the vessel in which it was originally placed. Centrifugation was used to separate solid and liquid phases after extraction or refluxing. Liquids were recovered from solids by decantation.

  10. Fundamental studies of carbon-based nanomaterials: Exploring the interface between nanotechnology and separation science

    Science.gov (United States)

    Vinci, John Cody

    A sample containing carbon nanoparticles (CNPs) was generated starting with the soot from the combustion of inexpensive paraffin oil in a flame. The complexity of the sample, however, required fractionation to isolate its components. Anion-exchange high-performance liquid chromatography (AE-HPLC) was used for the analysis and collection of soot-derived CNPs. The fractionated species were monitored by ultraviolet (UV) absorbance and laser-induced photoluminescence detection, providing the chromatographic UV absorbance and emission profiles of the separated sample. Chromatographic fractionation allowed for bulk measurements of electronic properties for individual fractions, and further analysis via transmission electron microscopy (TEM). TEM of fractionated species showed a predominant size of about 3-5 nm diameter particulates, including carbon dots (C-dots), irregularly-shaped/amorphous CNPs, and graphitic nanoribbons. A general trend between photoluminescence and elution time was observed; the later eluting species in the chromatogram exhibited photoluminescence at longer wavelengths than the early eluting species. Graphite nanofibers were shown to be effective for synthesizing C-dots exclusively but also exist as a relatively complex mixture. An unprecedented reduction in such complexity by AE-HPLC revealed fractions of C-dots with unique photoluminescence properties. The wavelength-dependent photoluminescence commonly assigned as an inherent property of C-dots was not present in fractionated samples. While UV-visible absorption profiles reported for C-dots are typically featureless, fractions of C-dots were found to possess unique absorption bands, with different fractions possessing specific emission wavelengths. Furthermore, fractionated C-dots showed profound differences in emission quantum yield, allowing for brighter C-dots to be isolated from an apparent low quantum yield mixture. These more photoluminescent fractions of C-dots displayed improved

  11. New cleaning strategies based on carbon nanomaterials applied to the deteriorated marble surfaces: A comparative study with enzyme based treatments

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, Federica, E-mail: federica.valentini@uniroma2.it [Dipartimento di Scienze e Tecnologie Chimiche, Universita degli Studi di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Diamanti, Alessia; Carbone, M. [Dipartimento di Scienze e Tecnologie Chimiche, Universita degli Studi di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Bauer, E.M. [Istituto di Struttura della Materia del Consiglio Nazionale delle Ricerche (ISM-CNR), RM 1, Via Salaria km 29.3, 00015 Monterotondo (Italy); Palleschi, Giuseppe [Dipartimento di Scienze e Tecnologie Chimiche, Universita degli Studi di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy)

    2012-06-01

    Pentelic marbles from Basilica Neptuni in Rome-Italy (27-25 B.C.) show the signs of deterioration phenomena, which can be identified as black crust as well as black and grey patina. The present study has the twofold objective of assessing the entity of the deterioration and proposing new cleaning strategies based on nanotechnologies. The former is achieved by performing optical microscopy, differential interference contrast (DIC), stereomicroscopy, scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) and infrared Fourier transform spectroscopy (FT-IR) analysis. The second objective of this study, involves different treatments based on a new cleaning strategy with carbon nanomaterials and bio-cleaning (used here for comparison) performed with enzymes, as glucose oxidase (GOD) and lipase. Nanomicelles assembled with functionalised carbon nano-fibres (CNF-COOH) and dispersed in Tween 20 medium show the highest cleaning performances in terms of removal of the black crust, compared with the pristine single-wall carbon nanotubes (SWCNTs) and the enzyme-based cleaning treatments. In particular, in these last two cases, the GOD-based biocleaning is efficient in removing the grey and dark patina, but works slow on the black crust. Finally, the lipase based cleaning approach is efficient in the black patina removal, though at the working temperature of 38 Degree-Sign C.

  12. Hydrophobic End-Modulated Amino-Acid-Based Neutral Hydrogelators: Structure-Specific Inclusion of Carbon Nanomaterials.

    Science.gov (United States)

    Choudhury, Pritam; Mandal, Deep; Brahmachari, Sayanti; Das, Prasanta Kumar

    2016-04-01

    Hydrophobic end-modulated l-phenylalanine-containing triethylene glycol monomethyl ether tagged neutral hydrogelators (1-4) are developed. Investigations determine the gelators' structure-dependent inclusion of carbon nanomaterials (CNMs) in the self-assembled fibrillar network (SAFIN). The gelators (1, 3, and 4) can immobilize water and aqueous buffer (pH 3-7) with a minimum gelator concentration of 10-15 mg mL(-1). The hydrophobic parts of the gelators are varied from a long chain (C-16) to an extended aromatic pyrenyl moiety, and their abilities to integrate 1 D and 2 D allotropes of carbon (i.e., single-walled carbon nanotubes (SWNTs) and graphene oxide (GO), respectively) within the gel are investigated. Gelator 1, containing a long alkyl chain (C-16), can include SWNTs, whereas the pyrene-containing 4 can include both SWNTs and GO. Gelator 3 fails to incorporate SWNTs or GO owing to its slow rate of gelation and possibly a mismatch between the aggregated structure and CNMs. The involvement of various forces in self-aggregated gelation and physicochemical changes occurring through CNM inclusion are examined by spectroscopic and microscopic techniques. The distinctive pattern of self-assembly of gelators 1 and 4 through J- and H-type aggregation might facilitate the structure-specific CNM inclusion. Inclusion of SWNTs/GO within the hydrogel matrix results in a reinforcement in mechanical stiffness of the composites compared with that of the native hydrogels.

  13. 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

  14. Nanomaterials handbook

    CERN Document Server

    Gogotsi, Yury

    2006-01-01

    Even before it was identified as a science and given a name,  nanotechnology was the province of the most innovative inventors. In medieval times, craftsmen, ingeniously employing nanometer-sized gold particles, created the enchanting red hues found in the gold ruby glass of cathedral windows. Today, nanomaterials are being just as creatively used to improve old products, as well as usher in new ones. From tires to CRTs to sunscreens, nanomaterials are becoming a part of every industry. The Nanomaterials Handbook provides a comprehensive overview of the current state of nanomaterials. Employ

  15. Exploring the cellular and tissue uptake of nanomaterials in a range of biological samples using multimodal nonlinear optical microscopy

    Science.gov (United States)

    Johnston, Helinor J.; Mouras, Rabah; Brown, David M.; Elfick, Alistair; Stone, Vicki

    2015-12-01

    The uptake of nanomaterials (NMs) by cells is critical in determining their potential biological impact, whether beneficial or detrimental. Thus, investigation of NM internalization by cells is a common consideration in hazard and efficacy studies. There are currently a number of approaches that are routinely used to investigate NM-cell interactions, each of which have their own advantages and limitations. Ideally, imaging modalities used to investigate NM uptake by cells should not require the NM to be labelled (e.g. with fluorophores) to facilitate its detection. We present a multimodal imaging approach employing a combination of label-free microscopies that can be used to investigate NM-cell interactions. Coherent anti-Stokes Raman scattering microscopy was used in combination with either two-photon photoluminescence or four-wave mixing (FWM) to visualize the uptake of gold or titanium dioxide NMs respectively. Live and fixed cell imaging revealed that NMs were internalized by J774 macrophage and C3A hepatocyte cell lines (15-31 μg ml-1). Sprague Dawley rats were exposed to NMs (intratracheal instillation, 62 μg) and NMs were detected in blood and lung leucocytes, lung and liver tissue, demonstrating that NMs could translocate from the exposure site. Obtained data illustrate that multimodal nonlinear optical microscopy may help overcome current challenges in the assessment of NM cellular uptake and biodistribution. It is therefore a powerful tool that can be used to investigate unlabelled NM cellular and tissue uptake in three dimensions, requires minimal sample preparation, and is applicable to live and fixed cells.

  16. Application of a Fused Carbon Nanomaterial Filter for Lunar Dust Abatement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Seldon Laboratories, LLC, will apply its patented carbon nanotube filtration technology for air and nanoscale particulate engine exhaust filtration to NASA's Lunar...

  17. Application of a Fused Carbon Nanomaterial Filter for Lunar Dust Abatement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Seldon Technologies will further test and develop its patented carbon nanotube filtration technology to NASA's Lunar Exploration challenges. This project focuses on...

  18. 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

  19. Mixed low-dimensional nanomaterial: 2D ultranarrow MoS2 inorganic nanoribbons encapsulated in quasi-1D carbon nanotubes.

    Science.gov (United States)

    Wang, Zhiyong; Li, Hong; Liu, Zheng; Shi, Zujin; Lu, Jing; Suenaga, Kazu; Joung, Soon-Kil; Okazaki, Toshiya; Gu, Zhennan; Zhou, Jing; Gao, Zhengxiang; Li, Guangping; Sanvito, Stefano; Wang, Enge; Iijima, Sumio

    2010-10-01

    Quasi-one-dimensional nanotubes and two-dimensional nanoribbons are two fundamental forms of nanostructures, and integrating them into a novel mixed low-dimensional nanomaterial is fascinating and challenging. We have synthesized a stable mixed low-dimensional nanomaterial consisting of MoS(2) inorganic nanoribbons encapsulated in carbon nanotubes (which we call nanoburritos). This route can be extended to the synthesis of nanoburritos composed of other ultranarrow transition-metal chalcogenide nanoribbons and carbon nanotubes. The widths of previously synthesized MoS(2) ribbons are greater than 50 nm, while the encapsulated MoS(2) nanoribbons have uniform widths down to 1-4 nm and layer numbers down to 1-3, depending on the nanotube diameter. The edges of the MoS(2) nanoribbons have been identified as zigzag-shaped using both high-resolution transmission electron microscopy and density functional theory calculations. PMID:20828123

  20. Fibrinogen enhances the inflammatory response of alveolar macrophages to TiO2, SiO2 and carbon nanomaterials.

    Science.gov (United States)

    Marucco, Arianna; Gazzano, Elena; Ghigo, Dario; Enrico, Emanuele; Fenoglio, Ivana

    2016-01-01

    Many studies have shown that the composition of the protein corona dramatically affects the response of cells to nanomaterials (NMs). However, the role of each single protein is still largely unknown. Fibrinogen (FG), one of the most abundant plasma proteins, is believed to mediate foreign-body reactions. Since this protein is absent in cell media used in in vitro toxicological tests the possible FG-mediated effects have not yet been assessed. Here, the effect of FG on the toxicity of three different kinds of inorganic NMs (carbon, SiO2 and TiO2) on alveolar macrophages has been investigated. A set of integrated techniques (UV-vis spectroscopy, dynamic light scattering and sodium dodecyl sulphate-polyacrylamide gel electrophoresis) have been used to study the strength and the kinetics of interaction of FG with the NMs. The inflammatory response of alveolar macrophages (MH-S) exposed to the three NMs associated with FG has also been investigated. We found that FG significantly enhances the cytotoxicity (lactate dehydrogenase leakage) and the inflammatory response (increase in nitric oxide (NO) concentration and NO synthase activation) induced by SiO2, carbon and TiO2 NMs on alveolar macrophages. This effect appears related to the amount of FG interacting with the NMs. In the case of carbon NMs, the activation of fibrinolysis, likely related to the exposure of cryptic sites of FG, was also observed after 24 h. These findings underline the critical role played by FG in the toxic response to NMs.

  1. Supercritical CO2-driven,periodic patterning on one-dimensionals carbon nanomaterials

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    One-dimensional carbon nano-materials,in particular carbon nanotubes (CNTs) and carbon nanofibers (CNFs),are of scientific and technological interest due to their satisfactory properties and ability to serve as templates for directed assembly.In this work,linear high density polyethylene (PE) was periodically decorated on CNTs and CNFs using a supercritical carbon dioxide (scCO2)antisolvent-induced polymer epitaxy (SAIPE) method,leading to nano-hybrid shish-kebab (NHSK) structures.The formation mechanism of different morphologies of PE lamellae on CNTs and CNFs has been discussed.Palladium nanoparticles were synthesized and immobilized on the PE/CNF NHSK structure with the assistance of scCO2.The obtained hierarchical nano-hybrid architecture may find applications in microfabrication and other related fields.

  2. Nd:Yag laser irradiation of single lap joints made by polyethylene and polyethylene doped by carbon nanomaterials

    Science.gov (United States)

    Visco, A. M.; Brancato, V.; Cutroneo, M.; Torrisi, L.

    2014-04-01

    Thermoplastic polyethylene can be welded by the transmission laser welding technique (TTLW) that exhibits some process related benefits with respect other conventional joining methods. This justifies its large use in wide fields, from the automotive to medical or domestic appliances. In this research, we studied single lap joints made by polyethylene pure and filled with carbon nanomaterials (0.2% in weight) to make the polymer laser absorbent. The joints were irradiated by a Nd:YAG laser operating at 1064 nm (first harmonic) with an intensity of 107 W/cm2 and 1 ÷ 30Hz, a maximum pulse energy of 300mJ and a laser spot of ≈ 1 cm2 (no focusing lens were employed). The joints were characterized by morphological analysis, mechanical shear tests and calorimetric analysis. The results suggested that the laser exposition time must be opportunely balanced in order to avoid a poor adhesion between the polymer sheets and to realized efficient joints. In particular the mechanical test showed that the laser exposition time of 40 seconds is the best conditions to obtain the highest shear strength of the joints of 140 N. After too prolonged laser exposure times, degrading phenomena starts.

  3. Nd:Yag laser irradiation of single lap joints made by polyethylene and polyethylene doped by carbon nanomaterials

    International Nuclear Information System (INIS)

    Thermoplastic polyethylene can be welded by the transmission laser welding technique (TTLW) that exhibits some process related benefits with respect other conventional joining methods. This justifies its large use in wide fields, from the automotive to medical or domestic appliances. In this research, we studied single lap joints made by polyethylene pure and filled with carbon nanomaterials (0.2% in weight) to make the polymer laser absorbent. The joints were irradiated by a Nd:YAG laser operating at 1064 nm (first harmonic) with an intensity of 107 W/cm2 and 1 ÷ 30 Hz, a maximum pulse energy of 300 mJ and a laser spot of ≈ 1 cm2 (no focusing lens were employed). The joints were characterized by morphological analysis, mechanical shear tests and calorimetric analysis. The results suggested that the laser exposition time must be opportunely balanced in order to avoid a poor adhesion between the polymer sheets and to realized efficient joints. In particular the mechanical test showed that the laser exposition time of 40 seconds is the best conditions to obtain the highest shear strength of the joints of 140 N. After too prolonged laser exposure times, degrading phenomena starts.

  4. Nanomaterials application in electrochemical detection of heavy metals

    International Nuclear Information System (INIS)

    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.

  5. Investigation on carbon nanomaterials: Coaxial CNT-cylinders and CNT-polymer composite

    Indian Academy of Sciences (India)

    Kalpana Awasthi; T P Yadav; P R Mishra; S Awasthi; O N Srivastava

    2008-06-01

    The macroscopic coaxial carbon cylinders (dia. ∼ 0.5 cm with varying lengths, ∼ 7–10 cm) consisting of aligned carbon nanotube (CNT) stacks have been prepared by controlled spray pyrolysis method. The coaxial carbon cylinders of CNT stacks have been formed directly inside the quartz tube. Another study is done on multi-walled CNTs (MWNTs)–polymer (e.g. polyethylene oxide (PEO), polyacrylamide (PAM)) composite films. We have investigated the structural, electrical and mechanical properties of MWNTs–PEO composites. Composites with different wt% (between 0 and 50 wt% of MWNTs) have been prepared and characterized by the scanning electron microscopic technique. Enhanced electrical conductivity and mechanical strength were observed for the MWNTs–PEO composites. We have also studied the electrical property of MWNTs–PAM composite films.

  6. Enhancement of Nitrite Reduction Kinetics on Electrospun Pd-Carbon Nanomaterial Catalysts for Water Purification.

    Science.gov (United States)

    Ye, Tao; Durkin, David P; Hu, Maocong; Wang, Xianqin; Banek, Nathan A; Wagner, Michael J; Shuai, Danmeng

    2016-07-20

    We report a facile synthesis method for carbon nanofiber (CNF) supported Pd catalysts via one-pot electrospinning and their application for nitrite hydrogenation. A mixture of Pd acetylacetonate (Pd(acac)2), polyacrylonitrile (PAN), and nonfunctionalized multiwalled carbon nanotubes (MWCNTs) was electrospun and thermally treated to produce Pd/CNF-MWCNT catalysts. The addition of MWCNTs with a mass loading of 1.0-2.5 wt % (to PAN) significantly improved nitrite reduction activity compared to the catalyst without MWCNT addition. The results of CO chemisorption confirmed that the addition of MWCNTs increased Pd exposure on CNFs and hence improved catalytic activity.

  7. Enhancement of Nitrite Reduction Kinetics on Electrospun Pd-Carbon Nanomaterial Catalysts for Water Purification.

    Science.gov (United States)

    Ye, Tao; Durkin, David P; Hu, Maocong; Wang, Xianqin; Banek, Nathan A; Wagner, Michael J; Shuai, Danmeng

    2016-07-20

    We report a facile synthesis method for carbon nanofiber (CNF) supported Pd catalysts via one-pot electrospinning and their application for nitrite hydrogenation. A mixture of Pd acetylacetonate (Pd(acac)2), polyacrylonitrile (PAN), and nonfunctionalized multiwalled carbon nanotubes (MWCNTs) was electrospun and thermally treated to produce Pd/CNF-MWCNT catalysts. The addition of MWCNTs with a mass loading of 1.0-2.5 wt % (to PAN) significantly improved nitrite reduction activity compared to the catalyst without MWCNT addition. The results of CO chemisorption confirmed that the addition of MWCNTs increased Pd exposure on CNFs and hence improved catalytic activity. PMID:27387354

  8. Synthesis and non-covalent functionalization of carbon nanotubes rings: new nanomaterials with lectin affinity

    Science.gov (United States)

    Assali, Mohyeddin; Pernía Leal, Manuel; Fernández, Inmaculada; Khiar, Noureddine

    2013-03-01

    We present a mild and practical carbon nanotubes rings (CNRs) synthesis from non-covalent functionalized and water-soluble linear single-wall carbon nanotubes. The hemi-micellar-supramolecular self-organization of lactose-based glycolipid 1 on the ring surface, followed by photo-polymerization of the diacetylenic function triggered by UV light afforded the first water-soluble and biocompatible CNRs. The obtained donut-like nanoconstructs expose a high density of lactose moieties on their surface, and are able to engage specific interactions with Arachis hypogea lectin similar to glycoconjugates on the cell membrane.

  9. Nanomaterial Registry

    Data.gov (United States)

    U.S. Department of Health & Human Services — By leveraging and developing a set of Minimal Information About Nanomaterials (MIAN), ontology and standards through a community effort, it has developed a data...

  10. Synthesis of Carbon Nanotube-Inorganic Hybrid Nanocomposites: An Instructional Experiment in Nanomaterials Chemistry

    Science.gov (United States)

    de Dios, Miguel; Salgueirino, Veronica; Perez-Lorenzo, Moises; Correa-Duarte, Miguel A.

    2012-01-01

    An experiment is described to introduce advanced undergraduate students to an exciting area of nanotechnology that incorporates nanoparticles onto carbon nanotubes to produce systems that have valuable technological applications. The synthesis of such material has been easily achieved through a simple three-step procedure. Students explore…

  11. 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. PMID:23580370

  12. Recent developments in the layer-by-layer assembly of polyaniline and carbon nanomaterials for energy storage and sensing applications. From synthetic aspects to structural and functional characterization

    Science.gov (United States)

    Marmisollé, Waldemar A.; Azzaroni, Omar

    2016-05-01

    The construction of hybrid polymer-inorganic nanoarchitectures for electrochemical purposes based on the layer-by-layer assembly of conducting polymers and carbon nanomaterials has become increasingly popular over the last decade. This explosion of interest is primarily related to the increasing mastery in the design of supramolecular constructs using simple wet chemical approaches. Concomitantly, this continuous research activity paved the way to the rapid development of nanocomposites or ``nanoblends'' readily integrable into energy storage and sensing devices. In this sense, the layer-by-layer (LbL) assembly technique has allowed us to access three-dimensional (3D) multicomponent carbon-based network nanoarchitectures displaying addressable electrical, electrochemical and transport properties in which conducting polymers, such as polyaniline, and carbon nanomaterials, such as carbon nanotubes or nanographene, play unique roles without disrupting their inherent functions - complementary entities coexisting in harmony. Over the last few years the level of functional sophistication reached by LbL-assembled carbon-based 3D network nanoarchitectures, and the level of knowledge related to how to design, fabricate and optimize the properties of these 3D nanoconstructs have advanced enormously. This feature article presents and discusses not only the recent advances but also the emerging challenges in complex hybrid nanoarchitectures that result from the layer-by-layer assembly of polyaniline, a quintessential conducting polymer, and diverse carbon nanomaterials. This is a rapidly developing research area, and this work attempts to provide an overview of the diverse 3D network nanoarchitectures prepared up to now. The importance of materials processing and LbL integration is explored within each section and while the overall emphasis is on energy storage and sensing applications, the most widely-used synthetic strategies and characterization methods for ``nanoblend

  13. Electron paramagnetic resonance and Raman spectroscopy studies on carbon-doped MgB{sub 2} superconductor nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Bateni, Ali; Somer, Mehmet, E-mail: emre.erdem@physchem.uni-freiburg.de, E-mail: msomer@ku.edu.tr [Department of Chemistry, Koc University, RumelifeneriYolu, Sariyer, Istanbul (Turkey); Erdem, Emre, E-mail: emre.erdem@physchem.uni-freiburg.de, E-mail: msomer@ku.edu.tr; Repp, Sergej; Weber, Stefan [Institut für Physikalische Chemie, Universität Freiburg, Albertstr. 21, 79104 Freiburg (Germany); Acar, Selcuk; Kokal, Ilkin [Pavezyum Kimya Sanayi Dış Ticaret LTD. ŞTI., Tuzla, Istanbul (Turkey); Häßler, Wolfgang [Leibniz Institute for Solid State and Materials Research Dresden (IFW), P.O. Box 270116, 01171 Dresden (Germany)

    2015-04-21

    Undoped and carbon-doped magnesium diboride (MgB{sub 2}) samples were synthesized using two sets of mixtures prepared from the precursors, amorphous nanoboron, and as-received amorphous carbon-doped nanoboron. The microscopic defect structures of carbon-doped MgB{sub 2} samples were systematically investigated using X-ray powder diffraction, Raman and electron paramagnetic resonance spectroscopy. Mg vacancies and C-related dangling-bond active centers could be distinguished, and sp{sup 3}-hybridized carbon radicals were detected. A strong reduction in the critical temperature T{sub c} was observed due to defects and crystal distortion. The symmetry effect of the latter is also reflected on the vibrational modes in the Raman spectra.

  14. 碳纳米材料在环境中的转化%The environmental transformation of carbon nanomaterials

    Institute of Scientific and Technical Information of China (English)

    张礼文; 黄庆国; 毛亮

    2013-01-01

    碳纳米材料主要包括富勒烯、碳纳米管和石墨烯。随着碳纳米材料的研究和应用范围不断扩大,其对环境的影响和在环境中的行为也逐渐受到关注,而在环境中的转化是环境行为的一个重要方面。首先,环境转化会改变碳纳米材料的性质,从而影响其它行为如聚集沉降和生态毒性。同时,作为一种以碳为骨架的材料,能否被自然界转化、从而进入碳循环是评价碳纳米材料长期环境影响的必要信息。因此,本文重点总结了碳纳米材料在自然环境条件和水处理条件下可能发生的生物或非生物转化,并分析影响碳纳米材料转化的因素,和转化过程对其环境行为的影响。%Carbon nanomaterials ( CNMs ) mainly include fullerenes, carbon nanotubes ( CNTs ) and graphenes. Mass production of CNMs is rapidly growing, and their entry to the environment is inevitable. Such releases of CNMs may cause undesired/unforeseen risks to the environment and human/wildlife health. A scientific assessment of such risks requires a thorough understanding of the environmental behaviors of CNMs, such as their fate, transport and transformation. This review focused on the environmentally relevant transformation of CNMs, especially those that can change the properties of CNMs and thus influence their behaviors in and impacts to the environment. As a category of carbon-based material, whether they can fit in the carbon cycle is also an important aspect in assessing their long-term effect. Therefore, in this review we summarized the possible transformation of CNMs in natural conditions or waste treatment conditions, either biotic or abiotic. Meanwhile, the factors influencing the transformation were analyzed.

  15. N-doped carbon nanomaterials are durable catalysts for oxygen reduction reaction in acidic fuel cells.

    Science.gov (United States)

    Shui, Jianglan; Wang, Min; Du, Feng; Dai, Liming

    2015-02-01

    The availability of low-cost, efficient, and durable catalysts for oxygen reduction reaction (ORR) is a prerequisite for commercialization of the fuel cell technology. Along with intensive research efforts of more than half a century in developing nonprecious metal catalysts (NPMCs) to replace the expensive and scarce platinum-based catalysts, a new class of carbon-based, low-cost, metal-free ORR catalysts was demonstrated to show superior ORR performance to commercial platinum catalysts, particularly in alkaline electrolytes. However, their large-scale practical application in more popular acidic polymer electrolyte membrane (PEM) fuel cells remained elusive because they are often found to be less effective in acidic electrolytes, and no attempt has been made for a single PEM cell test. We demonstrated that rationally designed, metal-free, nitrogen-doped carbon nanotubes and their graphene composites exhibited significantly better long-term operational stabilities and comparable gravimetric power densities with respect to the best NPMC in acidic PEM cells. This work represents a major breakthrough in removing the bottlenecks to translate low-cost, metal-free, carbon-based ORR catalysts to commercial reality, and opens avenues for clean energy generation from affordable and durable fuel cells.

  16. N-doped carbon nanomaterials are durable catalysts for oxygen reduction reaction in acidic fuel cells

    Science.gov (United States)

    Shui, Jianglan; Wang, Min; Du, Feng; Dai, Liming

    2015-01-01

    The availability of low-cost, efficient, and durable catalysts for oxygen reduction reaction (ORR) is a prerequisite for commercialization of the fuel cell technology. Along with intensive research efforts of more than half a century in developing nonprecious metal catalysts (NPMCs) to replace the expensive and scarce platinum-based catalysts, a new class of carbon-based, low-cost, metal-free ORR catalysts was demonstrated to show superior ORR performance to commercial platinum catalysts, particularly in alkaline electrolytes. However, their large-scale practical application in more popular acidic polymer electrolyte membrane (PEM) fuel cells remained elusive because they are often found to be less effective in acidic electrolytes, and no attempt has been made for a single PEM cell test. We demonstrated that rationally designed, metal-free, nitrogen-doped carbon nanotubes and their graphene composites exhibited significantly better long-term operational stabilities and comparable gravimetric power densities with respect to the best NPMC in acidic PEM cells. This work represents a major breakthrough in removing the bottlenecks to translate low-cost, metal-free, carbon-based ORR catalysts to commercial reality, and opens avenues for clean energy generation from affordable and durable fuel cells. PMID:26601132

  17. Electrospun carbon nanotubes-gold nanoparticles embedded nanowebs: prosperous multi-functional nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-Gyung; Gopalan, Anantha Iyengar; Lee, Kwang-Pill [Department of Nano-Science and Technology, Kyungpook National University, Daegu, 702-701 (Korea, Republic of); Ragupathy, Dhanusuraman, E-mail: kplee@knu.ac.kr [Department of Chemistry Graduate School, Kyungpook National University, Daegu, 702-701 (Korea, Republic of)

    2010-04-02

    Electrospinning was employed to prepare new multi-functional nanowebs. Cyclodextrin based inclusion complex (CD-IC) was used to disperse multiwalled carbon nanotubes (MWNT) within electrospun polyvinylidene fluoride nanofibrous membranes (PVdF-NFM). Subsequently, MWNT(CD-IC)/PVdF-NFM was loaded with gold (Au) particles. The morphology, structure and thermal properties of Au/MWNT(CD-IC)/PVdF-NFM were investigated by transmission electron microscopy, field emission scanning electron microscopy, FT-IR spectroscopy, x-ray diffraction spectroscopy and differential scanning calorimetry. The new Au/MWNT(CD-IC)/PVdF-NFM is electroactive and shows excellent electrocatalytic activity towards oxidation of ascorbic acid.

  18. Effect of incorporating carbon nanocoils on the efficiency of electromagnetic-wave shielding of carbon-nanomaterial composites

    Science.gov (United States)

    Kang, Gi-Hwan; Kim, Sung-Hoon

    2016-09-01

    Carbon nanocoils (CNCs) were deposited on Al2O3 substrates using C2H2 and H2 as source gases in a thermal chemical vapor deposition system. Composites of CNCs in polyurethane (CNC@PU) and CNCs plus other carbon-based materials, such as carbon microcoils (CMCs) and carbon nanotubes (CNTs), in polyurethane (CNC + CMC@PU, CNC + CNT@PU) was fabricated. The electromagnetic-wave-shielding effectiveness of the CNCs-incorporated composites were examined and compared with those of other carbon-based materials in the measurement-frequency range of 0.25-4.0 GHz. The incorporation of CNCs in CMC@PU composites reduced the shielding effectiveness; on the other hand, it slightly enhanced the shielding effectiveness of CNT@PU composites within the measurement frequency range of 0.5-3.0 GHz. Based on the resulting shielding effectiveness, we conclude that the incorporation of CNCs was useful for the materials that exhibited reflection-based shielding effectiveness although the CNCs themselves had poor electrical conductivity.

  19. Potential application of carbon nanotube core as nanocontainer and nanoreactor for the encapsulated nanomaterial

    Science.gov (United States)

    Tyagi, Pawan K.; Kumari, Reetu; Bhatta, Umananda M.; Juluri, Raghavendra Rao; Rath, Ashutosh; Kumar, Sanjeev; Satyam, P. V.; Gautam, Subodh K.; Singh, Fouran

    2016-07-01

    Fe3C nanorod filled inside carbon nanotube has been irradiated inside transmission electron microscope at both room and high temperature. In-situ response of Fe3C nanorod as well as CNT walls has been studied. It has been found that when electron irradiation is performed at room temperature (RT), nanorod first bends and then tip makes at the end whereas at high temperature (∼490 °C) nanorod slides along the tube axis and then transforms into a faceting particle. Extrusion of solid particle filled in the core of CNT has also been demonstrated. It is suggested that these morphological changes in nanorod may have happened due to the compression which was generated either by shrinkage of tube or by local electron beam heating. Presented results demonstrate that CNT core could be used as nano-container or reactor.

  20. Nanomaterials for Space Exploration Applications

    Science.gov (United States)

    Moloney, Padraig G.

    2006-01-01

    Nano-engineered materials are multi-functional materials with superior mechanical, thermal and electrical properties. Nanomaterials may be used for a variety of space exploration applications, including ultracapacitors, active/passive thermal management materials, and nanofiltration for water recovery. Additional applications include electrical power/energy storage systems, hybrid systems power generation, advanced proton exchange membrane fuel cells, and air revitalization. The need for nanomaterials and their growth, characterization, processing and space exploration applications is discussed. Data is presented for developing solid-supported amine adsorbents based on carbon nanotube materials and functionalization of nanomaterials is examined.

  1. 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...... reviewed scientific literature, the current project has developed a scoring system that evaluates the liability and relevance of the data in relation to nanomaterials....

  2. Cs corrected STEM EELS: Analysing beam sensitive carbon nanomaterials in cellular structures

    Energy Technology Data Exchange (ETDEWEB)

    Gass, Mhairi H., E-mail: m.h.gass@liv.ac.uk [SuperSTEM, Daresbury Lab, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); Porter, Alexandra E. [Department of Materials, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom); Bendall, James S. [The Nanoscience Centre, University of Cambridge, 11 J.J. Thompson Avenue, Cambridge CB3 OFF (United Kingdom); Muller, Karin; Skepper, Jeremy N. [Multiimaging Centre, Department of PDN (Physiology, Development and Neuroscience), Anatomy Building, University of Cambridge, Downing Street, Cambridge CB2 3DY (United Kingdom); Midgley, Paul A. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Welland, Mark [The Nanoscience Centre, University of Cambridge, 11 J.J. Thompson Avenue, Cambridge CB3 OFF (United Kingdom)

    2010-07-15

    Identification of individual single wall nanotubes (SWNTs) within a cellular structure can provide vital information towards understanding the potential mechanisms of uptake, their localisation and whether their structure is transformed within a cell. To be able to image an individual SWNT in such an environment a resolution is required that is not usually appropriate for biological sections. Standard transmission electron microscopy (TEM) techniques such as bright field imaging of these cellular structures result in very weak contrast. Traditionally, researchers have stained the cells with heavy metal stains to enhance the cellular structure, however this can lead to confusion when analysing the samples at high resolution. Subsequently, alternative methods have been investigated to allow high resolution imaging and spectroscopy to identify SWNTs within the cell; here we will concentrate on the sample preparation and experimental methods used to achieve such resolution.

  3. Biosensor nanomaterials

    CERN Document Server

    Li, Songjun; Li, He; Banerjee, Ipsita A

    2011-01-01

    Focusing on the materials suitable for biosensor applications, such as nanoparticles, quantum dots, meso- and nanoporous materials and nanotubes, this text enables the reader to prepare the respective nanomaterials for use in actual devices by appropriate functionalization, surface processing or directed self-assembly. The main detection methods used are electrochemical, optical, and mechanical, providing solutions to challenging tasks.The result is a reference for researchers and developers, disseminating first-hand information on which nanomaterial is best suited to a particular applicat

  4. Carbon-covered magnetic nanomaterials and their application for the thermolysis of cancer cells

    Directory of Open Access Journals (Sweden)

    Yang Xu

    2010-03-01

    Full Text Available Yang Xu1, Meena Mahmood1, Ashley Fejleh1, Zhongrui Li1, Fumiya Watanabe1, Steve Trigwell2, Reginald B Little3, Vasyl P Kunets4, Enkeleda Dervishi1, Alexandru R Biris5, Gregory J Salamo4, Alexandru S Biris11Nanotechnology Center and Applied Science Department, University of Arkansas at Little Rock, Little Rock, AR, USA; 2Applied Science and Technology, ASRC Aerospace, NASA Kennedy Space Center, FL, USA; 3Department of Chemistry, Elizabeth City State University, Elizabeth City, NC, USA; 4Physics Department, University of Arkansas, Fayetteville, AR, USA; 5National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj Napoca, RomaniaAbstract: Three types of graphitic shelled-magnetic core (Fe, Fe/Co, and Co nanoparticles (named as C-Fe, C-Fe/Co, and C-Co NPs were synthesized by radio frequency-catalytic chemical vapor deposition (RF-cCVD. X-ray diffraction and X-ray photoelectron spectroscopy analysis revealed that the cores inside the carbon shells of these NPs were preserved in their metallic states. Fluorescence microscopy images indicated effective penetrations of the NPs through the cellular membranes of cultured cancer HeLa cells, both inside the cytoplasm and the nucleus. Low RF radiation of 350 kHz induced localized heating of the magnetic NPs, which triggered cell death. Apoptosis inducement was found to be dependent on the RF irradiation time and NP concentration. It was showed that the Fe-C NPs had a much higher ability of killing the cancer cells (over 99% compared with the other types of NPs (C-Co or C-Fe/Co, even at a very low concentration of 0.83 μg/mL. The localized heating of NPs inside the cancer cells comes from the hysteresis heating and resistive heating through eddy currents generated under the RF radiation. The RF thermal ablation properties of the magnetic NPs were correlated with the analysis provided by a superconducting quantum interference device (SQUID.Keywords: graphitic shelled, magnetic

  5. Nanometer-scale temperature measurements of phase change memory and carbon nanomaterials

    Science.gov (United States)

    Grosse, Kyle Lane

    This work investigates nanometer-scale thermometry and thermal transport in new electronic devices to mitigate future electronic energy consumption. Nanometer-scale thermal transport is integral to electronic energy consumption and limits current electronic performance. New electronic devices are required to improve future electronic performance and energy consumption, but heat generation is not well understood in these new technologies. Thermal transport deviates significantly at the nanometer-scale from macroscopic systems as low dimensional materials, grain structure, interfaces, and thermoelectric effects can dominate electronic performance. This work develops and implements an atomic force microscopy (AFM) based nanometer-scale thermometry technique, known as scanning Joule expansion microscopy (SJEM), to measure nanometer-scale heat generation in new graphene and phase change memory (PCM) devices, which have potential to improve performance and energy consumption of future electronics. Nanometer-scale thermometry of chemical vapor deposition (CVD) grown graphene measured the heat generation at graphene wrinkles and grain boundaries (GBs). Graphene is an atomically-thin, two dimensional (2D) carbon material with promising applications in new electronic devices. Comparing measurements and predictions of CVD graphene heating predicted the resistivity, voltage drop, and temperature rise across the one dimensional (1D) GB defects. This work measured the nanometer-scale temperature rise of thin film Ge2Sb2Te5 (GST) based PCM due to Joule, thermoelectric, interface, and grain structure effects. PCM has potential to reduce energy consumption and improve performance of future electronic memory. A new nanometer-scale thermometry technique is developed for independent and direct observation of Joule and thermoelectric effects at the nanometer-scale, and the technique is demonstrated by SJEM measurements of GST devices. Uniform heating and GST properties are observed for

  6. Cellulose nanomaterials in water treatment technologies.

    Science.gov (United States)

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

    2015-05-01

    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

  7. Synthesis, Characterization, and Catalytic Applications of Transition Metal Oxide/Carbonate Nanomaterials

    Science.gov (United States)

    Jin, Lei

    2011-12-01

    This thesis contains two parts: 1) Studies of novel synthesis methods and characterization of advanced functional manganese oxide octahedral molecular sieves (OMS) and their applications in Li/Air batteries, solvent free toluene oxidations, and ethane oxydehydrogenation (ODH) in the presence of CO2, recycling the green house gas. 2) Development of unique Ln2O2CO3 (Ln = rare earth) layered materials and ZnO/La2O2CO3 composites as clean energy biofuel catalysts. These parts are separated into five different focused topics included in this thesis. The first topic presents studies of catalytic activities of a single step synthesized gamma-MnO2 octahedral molecular sieve nano fiber in solvent free atmospheric oxidation of toluene with molecular oxygen. Solvent free atmospheric oxidation of toluene is a notoriously difficult liquid phase oxidation process due to the challenge of oxidizing sp³ hybridized carbon in inactive hydrocarbons. The synthesized gamma-MnO2 showed excellent catalytic activity and good selectivity under the mild atmospheric reflux system. Under optimized conditions, a 47.8% conversion of toluene, along with 57% selectivity of benzoic acid and 15% of benzaldehyde were obtained. The effects of reaction time, amount of catalyst and initiator, and the reusability of the catalyst were investigated. The second topic involves developing titanium containing gamma-MnO 2 (TM) hollow spheres as electrocatalysts in Li/Air Batteries. Li/air batteries have recently attracted interest because they have the largest theoretical specific energy (11,972 Wh.kg-1) among all practical electrochemical couples. In this study, unique hollow aspheric materials were prepared for the first time using a one-step synthesis method and fully characterized by various techniques. These prepared materials were found to have excellent electrocatalytic activation as cathode materials in lithium-air batteries with a very high specific capacity (up to 2.3 A.h/g of carbon). The third

  8. Effects of total CH4/Ar gas pressure on the structures and field electron emission properties of carbon nanomaterials grown by plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    The effects of total CH4/Ar gas pressure on the growth of carbon nanomaterials on Si (1 0 0) substrate covered with CoO nanoparticles, using plasma-enhanced chemical vapor deposition (PECVD), were investigated. The structures of obtained products were correlated with the total gas pressure and changed from pure carbon nanotubes (CNTs) through hybrid CNTs/graphene sheets (GSs), to pure GSs as the total gas pressure changed from 20 to 4 Torr. The total gas pressure influenced the density of hydrogen radicals and Ar ions in chamber, which in turn determined the degree of how CoO nanoparticles were deoxidized and ion bombardment energy that governed the final carbon nanomaterials. Moreover, the obtained hybrid CNTs/GSs exhibited a lower turn-on field (1.4 V/μm) emission, compared to either 2.7 V/μm for pure CNTs or 2.2 V/μm for pure GSs, at current density of 10 μA/cm2.

  9. Supramolecular Surface Modification of Carbon Nanomaterials and Their Applicaions%碳纳米材料的超分子表面修饰及应用

    Institute of Scientific and Technical Information of China (English)

    承倩怡; 周鼎; 韩宝航

    2011-01-01

    综述了近年来碳纳米材料的超分子修饰及应用研究.重点阐述碳纳米管和石墨烯通过不同的超分子作用(如π-π相互作用、疏水相互作用、氢键相互作用和静电相互作用等)进行修饰制备得到具有不同功能的超分子碳纳米材料,及其在光电材料、药物和基因传输及化学生物传感器等领域的应用.%The carbon nanomaterials possess unique physical and chemical properties due to their special structure, and become one topic of high interests in recent years. The supramolecular surface modification could improve their surface properties and dispersion ability, which have attracted widespread attention from the scientific communities. The current status about the modification of carbon nanomaterials, especially carbon nanotube and graphene, through various intermolecular interactions, such as π-π interaction, hydropho-bic interaction, hydrogen bonding, and electrostatic interaction, as well as their applications, such as in optoelectronic materials, drug and gene delivery systems, and chem- or bio-sensors were summarized and reviewed in this paper.

  10. Mechanical activation of graphite in air: A way to advanced carbon nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Baklanova, O.N., E-mail: baklanova@ihcp.ru; Drozdov, V.A.; Lavrenov, A.V.; Vasilevich, A.V.; Muromtsev, I.V.; Trenikhin, M.V.; Arbuzov, A.B.; Likholobov, V.A.; Gorbunova, O.V.

    2015-10-15

    A high-energy planetary mill AGO-2 was used for mechanical activation of synthetic graphite with the particle size of 25–30 μm and specific surface area S{sub BET} = 3.0 m{sup 2}/g in air for 1–60 min at a 100 g acceleration of milling bodies. The X-ray diffraction, Raman spectroscopy and electron microscopy studies showed that the 60 min mechanical activation of graphite decreases the number of graphene layers in graphite crystallites to 8–12 and induces their turbostratic disorder. The size of graphite particles decreases to 6.9 μm after 30 min of mechanical activation and increases to 12.1 μm when the time of mechanical activation is extended to 60 min. Similar changes are observed for the true density of graphite: after 60 min of mechanical activation it becomes equal to 2.48 ⋅ 10{sup 3} kg/m{sup 3}, which is by 10% higher than the true density of graphite not subjected to such treatment. The specific adsorption surface of graphite (S{sub BET}) reaches its maximum values, 427–460 m{sup 2}/g, after 7–12 min of mechanical activation. A further increase in the activation time to 30–60 min decreases S{sub BET} of graphite to 230–250 m{sup 2}/g. Due to attrition of steel milling bodies caused by mechanical activation, iron is accumulated in the samples and its content exceeds 5%. Iron is distributed uniformly in the graphite as the 30–100 and 3–5 nm particles of hematite and iron carbide. The IR spectroscopy study revealed the formation of 0.8 mEq/g of the hydroxyl, phenolic, lactone and carbonyl groups on the graphite surface in the course of mechanical activation. - Highlights: • Graphite was mechanically activated in air at a 100 g acceleration of milling bodies. • The amount of graphenes in graphite crystallites decreases to 8–12. • Graphite transforms into a nanocrystalline X-ray amorphous state. • A metal–graphite composite with the 30–100 and 3–5 nm iron particles is formed. • Oxygen-containing groups in the amount of

  11. Nanomaterial Based Sensors for NASA Missions

    Science.gov (United States)

    Koehne, Jessica E.

    2016-01-01

    Nanomaterials such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene and metal nanowires have shown interesting electronic properties and therefore have been pursued for a variety of space applications requiring ultrasensitive and light-weight sensor and electronic devices. We have been pursuing development of chemical and biosensors using carbon nanotubes and carbon nanofibers for the last several years and this talk will present the benefits of nanomaterials these applications. More recently, printing approaches to manufacturing these devices have been explored as a strategy that is compatible to a microgravity environment. Nanomaterials are either grown in house or purchased and processed as electrical inks. Chemical modification or coatings are added to the nanomaterials to tailor the nanomaterial to the exact application. The development of printed chemical sensors and biosensors will be discussed for applications ranging from crew life support to exploration missions.

  12. Easy conversion of protein-rich enoki mushroom biomass to a nitrogen-doped carbon nanomaterial as a promising metal-free catalyst for oxygen reduction reaction

    Science.gov (United States)

    Guo, Chaozhong; Liao, Wenli; Li, Zhongbin; Sun, Lingtao; Chen, Changguo

    2015-09-01

    The search for low-cost, highly active, and stable catalysts to replace the Pt-based catalysts for oxygen reduction reaction (ORR) has recently become a topic of interest. Herein, we report a new strategy to design a nitrogen-doped carbon nanomaterial for use as a metal-free ORR catalyst based on facile pyrolysis of protein-rich enoki mushroom (Flammulina velutipes) biomass at 900 °C with carbon nanotubes as a conductive agent and inserting matrix. We found that various forms of nitrogen (nitrile, pyrrolic and graphitic) were incorporated into the carbon molecular skeleton of the product, which exhibited more excellent ORR electrocatalytic activity and better durability in alkaline medium than those in acidic medium. Remarkably, the ORR half-wave potential measured on our material was around 0.81 V in alkaline medium, slightly lower than that on the commercial 20 wt% Pt/C catalyst (0.86 V). Meanwhile, the ORR followed the desired 4-electron transfer mechanism involving the direct reduction pathway. The ORR performance was also markedly better than or at least comparable to the leading results in the literature based on biomass-derived carbon-based catalysts. Besides, we significantly proposed that the graphitic-nitrogen species that is most responsible for the ORR activity can function as the electrocatalytically active center for ORR, and the pyrrolic-nitrogen species can act as an effective promoter for ORR only. The results suggested a promising route based on economical and sustainable fungi biomass towards the large-scale production of valuable carbon nanomaterials as highly active and stable metal-free catalysts for ORR under alkaline conditions.The search for low-cost, highly active, and stable catalysts to replace the Pt-based catalysts for oxygen reduction reaction (ORR) has recently become a topic of interest. Herein, we report a new strategy to design a nitrogen-doped carbon nanomaterial for use as a metal-free ORR catalyst based on facile pyrolysis of

  13. Porous substrates filled with nanomaterials

    Science.gov (United States)

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

    2014-08-19

    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.

  14. Total carbon measurement in whole tropical soil sample

    International Nuclear Information System (INIS)

    Soils are an important component in the biogeochemical cycle of carbon, storing about four times more carbon than biomass plants and nearly three times more than the atmosphere. Moreover, the carbon content is directly related on the capacity of water retention, fertility, among other properties. Thus, soil carbon quantification in field conditions is an important challenge related to carbon cycle and global climatic changes. Nowadays, Laser Induced Breakdown Spectroscopy (LIBS) can be used for qualitative elemental analyses without previous treatment of samples and the results are obtained quickly. New optical technologies made possible the portable LIBS systems and now, the great expectation is the development of methods that make possible quantitative measurements with LIBS. The goal of this work is to calibrate a portable LIBS system to carry out quantitative measures of carbon in whole tropical soil sample. For this, six samples from the Brazilian Cerrado region (Argisoil) were used. Tropical soils have large amounts of iron in their compositions, so the carbon line at 247.86 nm presents strong interference of this element (iron lines at 247.86 and 247.95). For this reason, in this work the carbon line at 193.03 nm was used. Using methods of statistical analysis as a simple linear regression, multivariate linear regression and cross-validation were possible to obtain correlation coefficients higher than 0.91. These results show the great potential of using portable LIBS systems for quantitative carbon measurements in tropical soils

  15. Miniaturized sample preparation based on carbon nanostructures

    OpenAIRE

    Cárdenas Soledad

    2014-01-01

    The evolution of analytical methodologies has been driven by the objective to reduce the complexity of sample treatment while increasing the efficiency of the overall analytical process. For this reason, the analytical chemist takes into consideration advances in other scientific areas and systematically evaluates the potential influence that such discoveries might have on its own discipline. This is the present situation with nanostructured materials, which have alrea...

  16. EDITORIAL: Whither nanomaterials? Whither nanomaterials?

    Science.gov (United States)

    Mallouk, Thomas E.; Pinkerton, Fred; Stetson, Ned

    2009-10-01

    As the journal Nanotechnology enters its third decade it is interesting to look back on the field and to think about where it may be headed in the future. The growth of the journal over the past twenty years mirrors that of the field, with exponentially rising numbers of citations and a widening diversity of topics that we identify as nanotechnology. In the early 1990s, Nanotechnology was focused primarily on nanoscale electronics and on scanning probe tools for fabricating and characterizing nanostructures. The synthesis and assembly of nanomaterials was already an active area in chemical research; however, it did not yet intersect strongly with the activities of the physics community, which was interested primarily in new phenomena that emerged on the nanoscale and on the devices that derived from them. In the 1990s there were several key advances that began to bridge this gap. Techniques were developed for making nanocrystals of compound semiconductors, oxides, and metals with very fine control over shape and superstructure. Carbon nanotubes were discovered and their unique electronic properties were demonstrated. Research on the self-assembly of organic molecules on surfaces led to the development of soft lithography and layer-by- layer assembly of materials. The potential to use DNA and then proteins as building blocks of precise assemblies of nanoparticles was explored. These bottom-up structures could not be made by top-down techniques, and their unique properties as components of sensors, electronic devices, biological imaging agents, and drug delivery vehicles began to change the definition of the field. Ten years ago, Inelke Malsch published a study on the scientific trends and organizational dynamics of nanotechology in Europe (1999 Nanotechnology 10 1-7). Scientists from a variety of disciplines were asked which areas of research they would include in the definition of nanotechnology. Although the article concluded with forward-looking thoughts in the

  17. SAMPLING ARTIFACTS IN MEASUREMENT OF ELEMENTAL AND ORGANIC CARBON: LOW VOLUME SAMPLING IN INDOOR AND OUTDOOR ENVIRONMENTS

    Science.gov (United States)

    Experiments were completed to determine the extent of artifacts from sampling elemental carbon (EC) and organic carbon (OC) under sample conditions consistent with personal sampling. Two different types of experiments were completed; the first examined possible artifacts from oil...

  18. 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,...

  19. A comparison of six major platelet functional tests to assess the impact of carbon nanomaterials on platelet function: a practical guide.

    Science.gov (United States)

    Laloy, Julie; Mullier, François; Alpan, Lutfiye; Mejia, Jorge; Lucas, Stéphane; Chatelain, Bernard; Toussaint, Olivier; Masereel, Bernard; Rolin, Stéphanie; Dogné, Jean-Michel

    2014-03-01

    The study of the haemocompatibility of nanomaterials that could be in contact with blood (e.g. nanoparticle (NP)-based drug-delivery system) is of major importance. The primary objective of this study was to compare the ability of six platelet functional tests to assess the impact of NPs on platelet function. The secondary objective was to determine an accurate and reliable screening test to measure the potential impact of NPs on primary haemostasis whatever their physicochemical properties. Four types of carbon NPs (carbon black, fullerenes, single-walled carbon nanotubes and multi-walled carbon nanotubes) were investigated on six platelet function tests: light transmission aggregometry, whole-blood impedance aggregometry, platelet function analyser-100 (PFA-100®) and Cone-and-Plate(let) analyser (Impact-R®), transmission- and field emission gun scanning electron microscopy (FEG-SEM). We considered that Impact-R® supported by FEG-SEM is the reference method to investigate the potential impact of NPs on platelet function.

  20. Evaluation of Nanomaterial Approaches to Damping in Epoxy Resin and Carbon Fiber/Epoxy Composite Structures by Dynamic Mechanical Analysis

    Science.gov (United States)

    Miller, G.; Heimann, Paula J.; Scheiman, Daniel A.; Duffy, Kirsten P.; Johnston, J. Chris; Roberts, Gary D.

    2013-01-01

    Vibration mitigation in composite structures has been demonstrated through widely varying methods which include both active and passive damping. Recently, nanomaterials have been investigated as a viable approach to composite vibration damping due to the large surface available to generate energy dissipation through friction. This work evaluates the influence of dispersed nanoparticles on the damping ratio of an epoxy matrix. Limited benefit was observed through dispersion methods, however nanoparticle application as a coating resulting in up to a three-fold increase in damping.

  1. Environmental assessment of nanomaterial use in Denmark

    DEFF Research Database (Denmark)

    Kjølholt, Jesper; Gottschalk, Fadri; Brinch, Anna;

    Protection Agency. The projects in NanoDEN have aimed to investigate and generate new environmentally relevant knowledge on of nanomaterials on the Danish market and to assess the possible associated risks to the environment. The results from the sub-projects are summarized in the current report...... to an overall assessment of nanomaterials risk to the environment in Denmark. The nine investigated nanomaterials are: Titanium Dioxide, Zinc Oxide, Silver, Carbon Nanotubes, Copper Oxide, Zero Valent Iron, Cerium Dioxide, Quantum Dots and Carbon Black....

  2. 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.

  3. Photoinduced toxicity of engineered nanomaterials

    Science.gov (United States)

    Jones, Philip Scott

    Engineered nanomaterials including metal, metal oxide and carbon based nanomaterials are extensively used in a wide variety of applications to the extent that their presence in the environment is expected to increase dramatically over the next century. These nanomaterials may be photodegraded by solar radiation and thereby release metal ions into the environment that can produce cytotoxic and genotoxic effects. Photoinduced toxicity experiments are performed exposing human lung epithelial carcinoma cells [H1650] to engineered semiconductor nanoparticles such as CdSe quantum dots and ZnO nanoparticles after exposure to 3, 6, and 9 hours of solar simulated radiation. Cytotoxicity and genotoxicity of the metal ions are evaluated using ZnSO4 and CdCl2 solutions for the MTT assay and Comet assay respectively. The objective of the dissertation is to obtain quantitative information about the environmental transformation of engineered nanomaterials and their mechanism of toxicity. This information is critical for addressing the environmental health and safety risks of engineered nanomaterials to workers, consumers and the environment.

  4. Comparison of methods for the quantification of carbonate carbon in atmospheric PM10 aerosol samples

    Science.gov (United States)

    Jankowski, Nicole; Schmidl, Christoph; Marr, Iain L.; Bauer, Heidi; Puxbaum, Hans

    Carbonate carbon (CC) represents an important fraction of atmospheric PM10 along with organic carbon (OC) and elemental carbon (EC), if specific sources (e.g. street abrasion, construction sites, desert dust) contribute to its composition. However, analytical methods for an easy and unambiguous determination of CC in atmospheric aerosols collected on filter matrices are scarce. We propose here a method for the determination of CC based on a heating pretreatment of the sample to remove OC and EC, followed by a total carbon determination to measure CC. This procedure is used for the correction of EC also determined by a heating pretreatment (Cachier, H., Bremond, M.P., Buat-Ménard, P., 1989. Determination of atmospheric soot carbon with a simple thermal method. Tellus 41B, 379-390) but without previous HCl fumigation, as proposed. Comparison of the carbon remaining after the proposed thermal treatment at 460 °C for 60 min in an oxygen stream showed good correlation for the carbonate carbon derived by calculation from the ionic balance for ambient air and street dust samples. Using the "three step" combustion technique it is now possible to determine OC, EC and CC by the use of a TC analyser in the concentration range of 2-200 μg carbon per sample aliquot, with good precision (3-5% RSD for TC and 5-10% for CC) and accuracy. In ambient air samples from a sampling site in Vienna with elevated PM10 levels ("Liesing") CC values as high as 25% of TC and 27% CO 32-; for street dust samples 32% of TC and 25% CO 32- of total PM10 mass were observed.

  5. 水或液氮中电弧放电制备炭纳米材料%The production of carbon nano-materials by arc discharge under water or liquid nitrogen

    Institute of Scientific and Technical Information of China (English)

    邢刚; 贾申利; 史宗谦

    2007-01-01

    The growth mechanism of carbon nano-materials by arc discharge in water or liquid nitrogen was investigated using a special arc discharge apparatus. High-resolution transmission electron microscopy was used to observe and analyze the products. Results indicated that multi-walled carbon nanotubes (MWCNTs) and carbon onions can be produced by arc discharge in water and liquid nitrogen respectively. Single-walled carbon nanohorns can be produced by arc discharge in liquid nitrogen, and cobalt encapsulated carbon nano-particles can be produced by cobalt catalyzed carbon arc discharge in water. The liquids acted as quenching walls for the nucleation and growth of carbon nano-materials, resulting in the formation of different forms of carbon nano-materials. A cross alternating magnetic field with a frequency 5 Hz can affect the nucleation of nano-materials to form MWCNTs or carbon onions because nucleation time is longer than the periodicity of the magnetic field. Based on the experimental phenomena, a primary physical model was proposed to interpret the growth of nano-materials by arc discharge in liquids.%利用特制的电弧放电装置,研究了水或液氮中碳电弧放电形成炭纳米材料的机理.借助高分辨率透射电子显微镜对电弧放电生成的产物进行了观察和分析.结果表明:在水或液氮中碳电弧放电可以生成多壁碳纳米管和碳纳米洋葱结构,液氮中碳电弧放电可以生成单壁碳纳米角,水中钴催化碳电弧放电可以生成碳包裹的纳米钴颗粒.横向低频交变磁场会影响碳纳米材料的形核过程,并且可以推测磁场交变的频率5 Hz与纳米管、纳米洋葱等结构的生长周期存在某种拟合.根据实验现象,提出了一种解释液体中碳电弧放电过程纳米材料生成的理论模型.

  6. Carbon Characterization Laboratory Readiness to Receive Irradiated Graphite Samples

    Energy Technology Data Exchange (ETDEWEB)

    Karen A. Moore

    2011-05-01

    The Carbon Characterization Laboratory (CCL) is located in Labs C19 and C20 of the Idaho National Laboratory Research Center. The CCL was established under the Next Generation Nuclear Plant Project to support graphite and ceramic composite research and development activities. The research conducted in this laboratory will support the Advanced Graphite Creep experiments—a major series of material irradiation experiments within the Next Generation Nuclear Plant Graphite program. The CCL is designed to characterize and test low activated irradiated materials such as high purity graphite, carbon-carbon composites, silicon-carbide composite, and ceramic materials. The laboratory is fully capable of characterizing material properties for both irradiated and nonirradiated materials. Major infrastructural modifications were undertaken to support this new radiological facility at Idaho National Laboratory. Facility modifications are complete, equipment has been installed, radiological controls and operating procedures have been established and work management documents have been created to place the CCL in readiness to receive irradiated graphite samples.

  7. Adventitious Carbon on Primary Sample Containment Metal Surfaces

    Science.gov (United States)

    Calaway, M. J.; Fries, M. D.

    2015-01-01

    Future missions that return astromaterials with trace carbonaceous signatures will require strict protocols for reducing and controlling terrestrial carbon contamination. Adventitious carbon (AC) on primary sample containers and related hardware is an important source of that contamination. AC is a thin film layer or heterogeneously dispersed carbonaceous material that naturally accrues from the environment on the surface of atmospheric exposed metal parts. To test basic cleaning techniques for AC control, metal surfaces commonly used for flight hardware and curating astromaterials at JSC were cleaned using a basic cleaning protocol and characterized for AC residue. Two electropolished stainless steel 316L (SS- 316L) and two Al 6061 (Al-6061) test coupons (2.5 cm diameter by 0.3 cm thick) were subjected to precision cleaning in the JSC Genesis ISO class 4 cleanroom Precision Cleaning Laboratory. Afterwards, the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.

  8. Nanomaterials-based electrochemical sensors for nitric oxide

    International Nuclear Information System (INIS)

    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 TiO2). 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)

  9. Planar graphene oxide-based magnetic ionic liquid nanomaterial for extraction of chlorophenols from environmental water samples coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cai, Mei-Qiang; Su, Jie; Hu, Jian-Qiang; Wang, Qian; Dong, Chun-Ying; Pan, Sheng-Dong; Jin, Mi-Cong

    2016-08-12

    A planar graphene oxide-based magnetic ionic liquid nanomaterial (PGO-MILN) was synthesized. The prepared PGO-MILN was characterized by transmission electronmicroscopy (TEM) and Fourier-transform infrared spectrometry (FTIR). The results of adsorption experiments showed that the PGO-MILN had great adsorption capacity for 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP). Based on the adsorption experimental data, a sensitive magnetic method for determination of the five CPs in environmental water samples was developed by an effective magnetic solid-phase extraction (MSPE) procedure coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effects of main MSPE parameters including the solution pH, extraction time, desorption time, and volume of desorption solution on the extraction efficiencies had been investigated in detail. The recoveries ranged from 85.3 to 99.3% with correlation coefficients (r) higher than 0.9994 and the linear ranges were between 10 and 500ngL(-1). The limits of detection (LODs) and limits of quantification (LOQs) of the five CPs ranged from 0.2 to 2.6ngL(-1) and 0.6 to 8.7ngL(-1), respectively. The intra- and inter- day relative standard deviations (RSDs) were in the range from 0.6% to 7.4% and from 0.7% to 8.4%, respectively. It was confirmed that the PGO-MILN was a kind of highly effective MSPE materials used for enrichment of trace CPs in the environmental water. PMID:27425762

  10. Planar graphene oxide-based magnetic ionic liquid nanomaterial for extraction of chlorophenols from environmental water samples coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Cai, Mei-Qiang; Su, Jie; Hu, Jian-Qiang; Wang, Qian; Dong, Chun-Ying; Pan, Sheng-Dong; Jin, Mi-Cong

    2016-08-12

    A planar graphene oxide-based magnetic ionic liquid nanomaterial (PGO-MILN) was synthesized. The prepared PGO-MILN was characterized by transmission electronmicroscopy (TEM) and Fourier-transform infrared spectrometry (FTIR). The results of adsorption experiments showed that the PGO-MILN had great adsorption capacity for 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP). Based on the adsorption experimental data, a sensitive magnetic method for determination of the five CPs in environmental water samples was developed by an effective magnetic solid-phase extraction (MSPE) procedure coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effects of main MSPE parameters including the solution pH, extraction time, desorption time, and volume of desorption solution on the extraction efficiencies had been investigated in detail. The recoveries ranged from 85.3 to 99.3% with correlation coefficients (r) higher than 0.9994 and the linear ranges were between 10 and 500ngL(-1). The limits of detection (LODs) and limits of quantification (LOQs) of the five CPs ranged from 0.2 to 2.6ngL(-1) and 0.6 to 8.7ngL(-1), respectively. The intra- and inter- day relative standard deviations (RSDs) were in the range from 0.6% to 7.4% and from 0.7% to 8.4%, respectively. It was confirmed that the PGO-MILN was a kind of highly effective MSPE materials used for enrichment of trace CPs in the environmental water.

  11. 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.

  12. Nanomaterials in Sensors

    OpenAIRE

    BelBruno, Joseph J.

    2013-01-01

    This Special Issue of Nanomaterials is focused on the continuing implementation of nanomaterials and nanostructures in the development of more sensitive and more specific sensing devices. As a result, these new devices employ smaller sensing elements and provide more “real time” capability. Often, the inclusion of nanomaterials leads to sensing elements for targets that were previously inaccessible.

  13. 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.

  14. Estimation of carbon and sulphur in MDU samples by combustion method using carbon sulphur analyser

    International Nuclear Information System (INIS)

    Full text: The present paper describes an analytical method followed at Control Laboratory, Nuclear Fuel Complex (NFC) for the determination of carbon and sulphur content in Magnesium Diuranate (MDU) which is the starting material for the production of Nuclear grade Uranium Dioxide (UO2) pellets. The knowledge of carbon and sulphur content in MDU is prerequisite since it poses process related problems during the conversion process of MDU to UO2 powder. A high content of carbon in MDU causes frothing during its dissolution in nitric acid before the solvent extraction step. Likewise high sulphur in the form of sulphate affects the efficiency of solvent extraction where-in uranium forms complex with sulphate which will not be extracted into the aqueous phase. This leads to retention of high quantity of uranium in raffinate affecting the overall production of UO2 powder. Hence, estimation of carbon and sulphur in MDU is vital for production process of UO2 powder. The sample under test is burnt in a pre-degassed ceramic crucible with tungsten and iron as accelerators in a stream of oxygen. During this process, the carbon and sulphur present in the sample gets converted to their respective oxides and detected by a non-dispersive infrared absorption detector. The complete experimental details are discussed in the paper. Also the paper presents comparison of carbon and sulphur content in MDU samples obtained from Turamdih and Jaduguda mines. In addition, the effect of heating of MDU samples to different temperatures on their carbon and sulphur contents is also studied. The sulphur content as sulphate obtained from Carbon-Sulphur Analyzer (CSA) is compared with those obtained from Wave Length Dispersive X-Ray Fluorescence Spectrometer (WD-XRFS)

  15. 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 ...

  16. Effects of carbon nanomaterials fullerene C60 and fullerol C60(OH)18–22 on gills of fish Cyprinus carpio (Cyprinidae) exposed to ultraviolet radiation

    International Nuclear Information System (INIS)

    In consequence of their growing use and demand, the inevitable environmental presence of nanomaterials (NMs) has raised concerns about their potential deleterious effects to aquatic environments. The carbon NM fullerene (C60), which forms colloidal aggregates in water, and its water-soluble derivative fullerol (C60(OH)18–22), which possesses antioxidant properties, are known to be photo-excited by ultraviolet (UV) or visible light. To investigate their potential hazards to aquatic organisms upon exposure to UV sunlight, this study analyzed (a) the in vitro behavior of fullerene and fullerol against peroxyl radicals (ROO·) under UV-A radiation and (b) the effects of these photo-excited NMs on oxidative stress parameters in functional gills extracted from the fish Cyprinus carpio (Cyprinidae). The variables measured were the total antioxidant capacity, lipid peroxidation (TBARS), the activities of the antioxidant enzymes glutathione reductase (GR) and glutamate cysteine ligase (GCL), and the levels of the non-enzymatic antioxidant glutathione (GSH). The obtained results revealed the following: (1) both NMs behaved in vitro as antioxidants against ROO· in the dark and as pro-oxidants in presence of UV-A, the latter effect being reversed by the addition of sodium azide, which is a singlet oxygen (1O2) quencher; (2) fullerene induced toxicity with or without UV-A incidence, with a significant (p 1O2 generation; and (3) fullerol also decreased GCL activity and GSH formation (p 1O2 formation.

  17. Facile and green approach to prepare fluorescent carbon dots: Emergent nanomaterial for cell imaging and detection of vitamin B2.

    Science.gov (United States)

    Kundu, Aniruddha; Nandi, Sudipta; Das, Pradip; Nandi, Arun K

    2016-04-15

    Carbon dots (CDs) are a new representative in carbonaceous family and have initiated remarkable research interests over the past one decade in a large variety of fields. Herein, we have utilized a facile, one-step carbonization method to prepare fluorescent carbon dots using poly(vinyl alcohol) (PVA) both as a carbon source and as a surface passivating agent. The as prepared CDs emit bright blue fluorescence under ultraviolet illumination. The structure and optical properties of the CDs are thoroughly investigated by several methods such as high-resolution transmission electron microscopy; dynamic light scattering; UV-vis, fluorescence and Fourier transform infrared spectroscopy. The CDs exhibit excellent water solubility and demonstrate average hydrodynamic diameter of 11.3 nm, holding great promise for biological applications. The biocompatibility evaluation and in vitro imaging study reveals that the synthesized CDs can be used as effective fluorescent probes in bio-imaging without noticeable cytotoxicity. In addition, a unique sensor for the detection of vitamin B2 in aqueous solution is proposed on the basis of spontaneous fluorescence resonance energy transfer from CD to vitamin B2. These findings therefore suggest that the CDs can find potential applications in cellular imaging along with sensing of vitamin B2.

  18. Facile and green approach to prepare fluorescent carbon dots: Emergent nanomaterial for cell imaging and detection of vitamin B2.

    Science.gov (United States)

    Kundu, Aniruddha; Nandi, Sudipta; Das, Pradip; Nandi, Arun K

    2016-04-15

    Carbon dots (CDs) are a new representative in carbonaceous family and have initiated remarkable research interests over the past one decade in a large variety of fields. Herein, we have utilized a facile, one-step carbonization method to prepare fluorescent carbon dots using poly(vinyl alcohol) (PVA) both as a carbon source and as a surface passivating agent. The as prepared CDs emit bright blue fluorescence under ultraviolet illumination. The structure and optical properties of the CDs are thoroughly investigated by several methods such as high-resolution transmission electron microscopy; dynamic light scattering; UV-vis, fluorescence and Fourier transform infrared spectroscopy. The CDs exhibit excellent water solubility and demonstrate average hydrodynamic diameter of 11.3 nm, holding great promise for biological applications. The biocompatibility evaluation and in vitro imaging study reveals that the synthesized CDs can be used as effective fluorescent probes in bio-imaging without noticeable cytotoxicity. In addition, a unique sensor for the detection of vitamin B2 in aqueous solution is proposed on the basis of spontaneous fluorescence resonance energy transfer from CD to vitamin B2. These findings therefore suggest that the CDs can find potential applications in cellular imaging along with sensing of vitamin B2. PMID:26852351

  19. 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

  20. Assessment of the toxic potential of graphene family nanomaterials

    OpenAIRE

    Xiaoqing Guo; Nan Mei

    2014-01-01

    Graphene, a single-atom-thick carbon nanosheet, has attracted great interest as a promising nanomaterial for a variety of bioapplications because of its extraordinary properties. However, the potential for widespread human exposure raises safety concerns about graphene and its derivatives, referred to as graphene-family nanomaterials. This review summarizes recent findings on the toxicological effects and the potential toxicity mechanisms of graphene-family nanomaterials in bacteria, mammalia...

  1. On the Mechanical Modeling, Visco-Elasticity and Application of Aerographite, a 3D Carbon Nano-Material

    OpenAIRE

    Schuchardt, Arnim

    2015-01-01

    A three dimensional carbon network material of seamless interconnected and hollow tubes, featuring a graphitic structure and an extremely low density has been designed and fabricated in cm3 volumes. The synthesis of this foam like material, named Aerographite, is based on highly-porous three dimensional networks from zinc oxide (ZnO) which are utilized as sacrifcial templates in a chemical vapor deposition (CVD) process. Such type of ZnO templates are produced by the flame transport synthesis...

  2. Neutral red interlinked gold nanoparticles/multiwalled carbon nanotubes hybrid nanomaterial and its application for the detection of NADH

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Fabricated a nanostructured hybrid material of GNPs/neutral red/MWCNTs. • GNPs decorated on MWCNT template by using neutral red as interlinker for first time. • Nanocomposite modified electrode employed successfully as sensor for NADH. • The electrode has high stability as it does not involve any biological entity. - Abstract: A novel nanocomposite of gold nanoparticles/neutral red/MWCNTs was prepared which was used to modify glassy carbon electrode. The prepared nanocomposite was physically characterized by scanning electron microscopy, transmission electron microscopy, zeta potential measurement, energy dispersive X-ray, FTIR spectroscopy, UV–visible spectroscopy. Electrochemical characterization was done using cyclic voltammetry technique. The modified glassy carbon electrode showed electrocatalytic activity toward the oxidation of NADH in 0.1 M phosphate buffer solution, pH 5.0. The modified electrode has better adhesion over the electrode surface, good stability as no leaching of neutral red based nanocomposite was observed. The oxidation of NADH started at 0.37 V and reached maxima at 0.52 V at the modified electrode surface. So the prepared composite modified electrode can be applied as electrochemical sensor for NADH. The sensitivity and detection limits of the modified glassy carbon electrode were found to be 0.588 μA/mM and 5 × 10−7 at signal to noise ratio 3

  3. Multi-walled carbon nanotubes: sampling criteria and aerosol characterization

    Science.gov (United States)

    Chen, Bean T.; Schwegler-Berry, Diane; McKinney, Walter; Stone, Samuel; Cumpston, Jared L.; Friend, Sherri; Porter, Dale W.; Castranova, Vincent; Frazer, David G.

    2015-01-01

    This study intends to develop protocols for sampling and characterizing multi-walled carbon nanotube (MWCNT) aerosols in workplaces or during inhalation studies. Manufactured dry powder containing MWCNT’s, combined with soot and metal catalysts, form complex morphologies and diverse shapes. The aerosols, examined in this study, were produced using an acoustical generator. Representative samples were collected from an exposure chamber using filters and a cascade impactor for microscopic and gravimetric analyses. Results from filters showed that a density of 0.008–0.10 particles per µm2 filter surface provided adequate samples for particle counting and sizing. Microscopic counting indicated that MWCNT’s, resuspended at a concentration of 10 mg/m3, contained 2.7 × 104 particles/cm3. Each particle structure contained an average of 18 nanotubes, resulting in a total of 4.9 × 105 nanotubes/cm3. In addition, fibrous particles within the aerosol had a count median length of 3.04 µm and a width of 100.3 nm, while the isometric particles had a count median diameter of 0.90 µm. A combination of impactor and microscopic measurements established that the mass median aerodynamic diameter of the mixture was 1.5 µm. It was also determined that the mean effective density of well-defined isometric particles was between 0.71 and 0.88 g/cm3, and the mean shape factor of individual nanotubes was between 1.94 and 2.71. The information obtained from this study can be used for designing animal inhalation exposure studies and adopted as guidance for sampling and characterizing MWCNT aerosols in workplaces. The measurement scheme should be relevant for any carbon nanotube aerosol. PMID:23033994

  4. Digital Rock Simulation of Flow in Carbonate Samples

    Science.gov (United States)

    Klemin, D.; Andersen, M.

    2014-12-01

    Reservoir engineering has becomes more complex to deal with current challenges, so core analysts must understand and model pore geometries and fluid behaviors at pores scales more rapidly and realistically. We introduce an industry-unique direct hydrodynamic pore flow simulator that operates on pore geometries from digital rock models obtained using microCT or 3D scanning electron microscope (SEM) images. The PVT and rheological models used in the simulator represent real reservoir fluids. Fluid-solid interactions are introduced using distributed micro-scale wetting properties. The simulator uses density functional approach applied for hydrodynamics of complex systems. This talk covers selected applications of the simulator. We performed microCT scanning of six different carbonate rock samples from homogeneous limestones to vuggy carbonates. From these, we constructed digital rock models representing pore geometries for the simulator. We simulated nonreactive tracer flow in all six digital models using a digital fluid description that included a passive tracer solution. During the simulation, we evaluated the composition of the effluent. Results of tracer flow simulations corresponded well with experimental data of nonreactive tracer floods for the same carbonate rock types. This simulation data of the non-reactive tracer flow can be used to calculate the volume of the rock accessible by the fluid, which can be further used to predict response of a porous medium to a reactive fluid. The described digital core analysis workflow provides a basis for a wide variety of activities, including input to design acidizing jobs and evaluating treatment efficiency and EOR economics. Digital rock multiphase flow simulations of a scanned carbonate rock evaluated the effect of wettability on flow properties. Various wetting properties were tested: slightly oil wet, slightly water wet, and water wet. Steady-state relative permeability simulations yielded curves for all three

  5. Highly thermal conductivity and infrared emissivity of flexible transparent film heaters utilizing silver-decorated carbon nanomaterials as fillers

    International Nuclear Information System (INIS)

    A flexible transparent film heater using functionalized few-walled carbon nanotubes and graphene nanosheets decorated with silver nanoparticles as fillers and poly(3,4-ethylenedioxythiophene)- poly(4-stryrenesulfonate) (PEDOT:PSS) as a dispersant possesses excellent optoelectronic and electrothermal properties. The film possesses a low sheet resistance of 53.0 ± 4.2 ohm · sq−1, a transmittance of 80.2 ± 0.8% at a wavelength of 550 nm, a high thermal conductivity of 142.0 ± 9.6 W · m−1 · K−1, a quick response time of less than 60 s, stable heating performance, good reliability, low power consumption, flexibility, and uniform heat diffusion. Besides, the film shows an average infrared emissivity of 0.53 in the wavelength range of 4 to 14 μm, which shows an outstanding heat release performance by radiation. The flexible transparent film heaters adopting graphene and carbon nanotubes as fillers boast excellent electrothermal performance through heat conduction and infrared radiation, suggesting that they are good substitutes for traditional metallic and indium tin oxide film heaters. (papers)

  6. From Fundamental Understanding To Predicting New Nanomaterials For High Capacity Hydrogen/Methane Storage and Carbon Capture

    Energy Technology Data Exchange (ETDEWEB)

    Yildirim, Taner [Univ. of Pennsylvania, Philadelphia, PA (United States)

    2015-03-03

    On-board hydrogen/methane storage in fuel cell-powered vehicles is a major component of the national need to achieve energy independence and protect the environment. The main obstacles in hydrogen storage are slow kinetics, poor reversibility and high dehydrogenation temperatures for the chemical hydrides; and very low desorption temperatures/energies for the physisorption materials (MOF’s, porous carbons). Similarly, the current methane storage technologies are mainly based on physisorption in porous materials but the gravimetric and volumetric storage capacities are below the target values. Finally, carbon capture, a critical component of the mitigation of CO2 emissions from industrial plants, also suffers from similar problems. The solid-absorbers such as MOFs are either not stable against real flue-gas conditions and/or do not have large enough CO2 capture capacity to be practical and cost effective. In this project, we addressed these challenges using a unique combination of computational, synthetic and experimental methods. The main scope of our research was to achieve fundamental understanding of the chemical and structural interactions governing the storage and release of hydrogen/methane and carbon capture in a wide spectrum of candidate materials. We studied the effect of scaffolding and doping of the candidate materials on their storage and dynamics properties. We reviewed current progress, challenges and prospect in closely related fields of hydrogen/methane storage and carbon capture.[1-5] For example, for physisorption based storage materials, we show that tap-densities or simply pressing MOFs into pellet forms reduce the uptake capacities by half and therefore packing MOFs is one of the most important challenges going forward. For room temperature hydrogen storage application of MOFs, we argue that MOFs are the most promising scaffold materials for Ammonia-Borane (AB) because of their unique interior active metal-centers for AB binding and well

  7. Nanomaterial cytotoxicity is composition, size, and cell type dependent

    Directory of Open Access Journals (Sweden)

    Sohaebuddin Syed K

    2010-08-01

    Full Text Available Abstract Background Despite intensive research efforts, reports of cellular responses to nanomaterials are often inconsistent and even contradictory. Additionally, relationships between the responding cell type and nanomaterial properties are not well understood. Using three model cell lines representing different physiological compartments and nanomaterials of different compositions and sizes, we have systematically investigated the influence of nanomaterial properties on the degrees and pathways of cytotoxicity. In this study, we selected nanomaterials of different compositions (TiO2 and SiO2 nanoparticles, and multi-wall carbon nanotubes [MWCNTs] with differing size (MWCNTs of different diameters 50 nm; but same length 0.5-2 μm to analyze the effects of composition and size on toxicity to 3T3 fibroblasts, RAW 264.7 macrophages, and telomerase-immortalized (hT bronchiolar epithelial cells. Results Following characterization of nanomaterial properties in PBS and serum containing solutions, cells were exposed to nanomaterials of differing compositions and sizes, with cytotoxicity monitored through reduction in mitochondrial activity. In addition to cytotoxicity, the cellular response to nanomaterials was characterized by quantifying generation of reactive oxygen species, lysosomal membrane destabilization and mitochondrial permeability. The effect of these responses on cellular fate - apoptosis or necrosis - was then analyzed. Nanomaterial toxicity was variable based on exposed cell type and dependent on nanomaterial composition and size. In addition, nanomaterial exposure led to cell type dependent intracellular responses resulting in unique breakdown of cellular functions for each nanomaterial: cell combination. Conclusions Nanomaterials induce cell specific responses resulting in variable toxicity and subsequent cell fate based on the type of exposed cell. Our results indicate that the composition and size of nanomaterials as well as the

  8. 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

  9. 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.

  10. Nanomaterials meet microfluidics.

    Science.gov (United States)

    Pumera, Martin

    2011-05-28

    Nanomaterials and lab-on-a-chip platforms have undergone enormous development during the past decade. Here, we present an overview of how microfluidics benefited from the use of nanomaterials for the enhanced separation and detection of analytes. We also discuss how nanomaterials benefit from microfluidics in terms of synthesis and in terms of the simulation of environments for nanomotors and nanorobots. In our opinion, the "marriage" of nanomaterials and microfluidics is highly beneficial and is expected to solve vital challenges in related fields.

  11. 碳纳米材料在生物医学领域的应用现状及展望%Application Status and Prospect of Carbon-Based Nanomaterials in Biomedical Field

    Institute of Scientific and Technical Information of China (English)

    张金超; 杨康宁; 张海松; 梁兴杰

    2013-01-01

    Nanomaterials have become a new type of materials with a rapid development of nanotechnology. Nanomaterials have unique physical and chemical properties such as small size effect, large surface area, high reactivity, and quantum effects. These features make the nanoscience as one of the three pillars of the world science. Carbon-based nanomaterials are an important part of nanomaterials, they include carbon nanotubes, fullerene, graphene, nanodiamond and their derivatives. Due to their unique physical and chemical properties, carbon-based nanomaterials have broad applications in the biomedical field. In addition, with the industrialization of nanotechnology, various forms of carbon-based nanomaterials have come into human life in different ways, and the biosafety is increasingly attracting attention of scientists around the world. This article reviews the potential applications of all four types of carbon-based nanomaterials in the biomedical field including tissue engineering, drug/gene carrier, biological imaging, cancer treatment, anti-HIV/anti-bacterial activity, and biological sensing. In addition, the biosafety issue is also reviewed. Finally, we discuss the need for future research. Specifically, we identify the most important research topics, which urgently need to be studied.%随着纳米技术的飞速发展,纳米材料已成为一种新型材料.纳米材料具有独特的物理化学性质,如小尺寸效应、巨大比表面积、极高的反应活性、量子效应等,这些特性使纳米科学成为当今世界三大支柱科学之一.碳纳米材料是纳米材料领域重要的组成部分,主要包括碳纳米管、富勒烯、石墨烯、纳米钻石及其衍生物等.由于其独特的理化特性,它们在生物医学领域具有广泛的应用前景.另外,随着碳纳米材料的产业化,各种形式的碳纳米材料将以不同途径进入人们的生活,纳米材料的生物安全性问题正受到世界各国科学家的广泛关注.

  12. Comparison of Shock-Deformed Carbonate Samples to Unshocked Carbonate Samples Using X-ray Powder Diffraction

    Science.gov (United States)

    Huson, S.; Foit, F.; Pope, M.

    2006-12-01

    Previous studies of carbonate minerals from meteorite impact craters have revealed broader X-ray powder diffraction (XRD) peaks when compared to those of unshocked mineral standards. In this study XRD patterns of shocked minerals from an impact crater are compared to those subjected to terrestrial tectonic processes as well as to undeformed mineral standards from our in-house collection. Shocked dolostone and limestone samples were collected from the central uplift and eroded crater rim of Sierra Madera, a well-exposed, complex impact crater located in west Texas. Unshocked samples of dolostone and limestone were collected from the Mission Canyon Formation of the Madison Limestone Group of southwest Montana and western Wyoming. The Mission Canyon Formation was deposited in a shallow shelf environment during the Mississippian, subsequently buried to varying depths, and deformed during the Laramide and Sevier orogenies in the Cretaceous. These samples are therefore excellent representatives for "normal" terrestrial tectonic processes. Samples were powdered, sieved through a 63 μm mesh sieve to ensure a uniform size, and sifted onto a vaseline coated zero background plate to reduce preferred orientation of grains. Patterns were collected over the range from 15° 120° 2θ with a step width of 0.02° 2θ and count-time of 10s per step. All patterns were analyzed using MDI Jade 7.0 software. Generally, samples collected in the field have XRD patterns that are not as sharp as the mineral standard patterns. With both shocked and unshocked samples, those containing dolomite show more XRD peak broadening than those without dolomite and at least one pattern of an unshocked dolostone sample is indistinguishable from a shocked dolostone pattern. However, dolostone samples in general are problematic. Previous researchers reported that the amount of magnesium in calcite may affect grinding properties and, therefore, influence XRD peak broadening. Currently, it is not always

  13. Nanomaterials science

    Directory of Open Access Journals (Sweden)

    Heinrich Rohrer

    2010-01-01

    interesting and daring research proposal, even if it interprets 'nano' somewhat too generously. After all, we want to promote top-class research and not average research just for the sake of 'nano'.Interfaces, material growth at given nano positions, shaping materials to a given nanosize and form, and bistability are key elements for functionalizing materials.InterfacesThe role of interfaces is rapidly increasing in science and technology. The number of interfaces increases with the square of the number of phases of materials. Even if the majority of them are impractical or useless, they are still much more abundant than the materials themselves, and they are the key to new functions. Think of the simple 'mechanical' interface responsible for the lotus effect where wetting is prevented by the rapidly changing surface curvature due to nanoparticles. Think of all the connections of a nanometer-sized area between very different materials, for example, for electron or spin transport. Think of the delicate interfaces that protect nanofunctional units from the environment but allow for communication of various types with other nanocomponents or with the macroscopic world. The solid–liquid interface plays a special role here. For me, it is the interface of the future, both for local growth and removal of nm3 quantities and for working with biological specimens requiring a liquid environment. Interfaces are the 'faces of action' and nanoscale materials science will be, to a great extent, 'interface science'. There is no need to change the name; attentive awareness suffices.Material growth at given nano positionsThis is the second central challenge in nanoscale materials science, but maybe still a futuristic one. We have heard much about the extraordinary properties of carbon nanotubes. They do a great job in certain applications, like tips of scanning tunneling and atomic force microscopes or nanoinjection needles or as bundles for electron emission or electron transport. As single

  14. Electrochemical sensor for Isoniazid based on the glassy carbon electrode modified with reduced graphene oxide–Au nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Zhuo, E-mail: guozhuochina@syuct.edu.cn [Department of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); Wang, Ze-yu [Department of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); Wang, Hui-hua, E-mail: hhwang@suda.edu.cn [Shagang School of Iron and Steel, Soochow University, Suzhou 215021 (China); Huang, Guo-qing; Li, Meng-meng [Department of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China)

    2015-12-01

    A sensitive electrochemical sensor has been fabricated to detect Isoniazid (INZ) using reduced graphene oxide (RGO) and Au nanocomposites (RGO–Au). RGO–Au nanocomposites were synthesized by a solution-based approach of chemical co-reduction of Au(III) and graphene oxide (GO), and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and Fourier transform infrared (FT-IR). The Au nanoparticles separate the RGO sheets in the precipitate and prevent RGO sheets from aggregation upon π–π stacking interactions. RGO–Au nanocomposites were used to modify the glassy carbon electrode (GCE). The electrochemical properties of RGO–Au/GCE were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the RGO–Au/GCE exhibited remarkably strong electrocatalytic activities towards INZ. Under the optimized conditions, there was linear relationships between the peak currents and the concentrations in the range of 1.0 × 10{sup −7} M to 1.0 × 10{sup −3} M for INZ, with the limit of detection (LOD) (based on S/N = 3) of 1.0 × 10{sup −8} M for INZ. - Highlights: • RGO–Au nanocomposites were synthesized and characterized by chemical co-reduction of Au (III) and GO. • RGO–Au/GCE was used as a sensitive electrochemical sensor to detect Isoniazid. • RGO–Au/GCE exhibited strong electrocatalytic activities towards Isoniazid.

  15. Nanomaterial Induced Immune Responses and Cytotoxicity.

    Science.gov (United States)

    Ali, Ashraf; Suhail, Mohd; Mathew, Shilu; Shah, Muhammad Ali; Harakeh, Steve M; Ahmad, Sultan; Kazmi, Zulqarnain; Alhamdan, Mohammed Abdul Rahman; Chaudhary, Adeel; Damanhouri, Ghazi Abdullah; Qadri, Ishtiaq

    2016-01-01

    Nanomaterials are utilized in a wide array of end user products such as pharmaceuticals, electronics, clothes and cosmetic products. Due to its size (< 100 nm), nanoparticles have the propensity to enter through the airway and skin, making its path perilous with the potential to cause damages of varying severity. Once within the body, these particles have unconstrained access to different tissues and organs including the brain, liver, and kidney. As a result, nanomaterials may cause the perturbation of the immune system eliciting an inflammatory response and cytotoxicity. This potential role is dependent on many factors such as the characteristics of the nanomaterials, presence or absence of diseases, and genetic predisposition. Cobalt and nickel nanoparticles, for example, were shown to have inflammogenic properties, while silver nanoparticles were shown to reduce allergic inflammation. Just as asbestos fibers, carbon nanotubes were shown to cause lungs damage. Some nanomaterials were shown, based on animal studies, to result in cell damage, leading to the formation of pre-cancerous lesions. This review highlights the impact of nanomaterials on immune system and its effect on human health with toxicity consideration. It recommends the development of suitable animal models to study the toxicity and bio-clearance of nanomaterials and propose safety guidelines.

  16. Nanomaterial Induced Immune Responses and Cytotoxicity.

    Science.gov (United States)

    Ali, Ashraf; Suhail, Mohd; Mathew, Shilu; Shah, Muhammad Ali; Harakeh, Steve M; Ahmad, Sultan; Kazmi, Zulqarnain; Alhamdan, Mohammed Abdul Rahman; Chaudhary, Adeel; Damanhouri, Ghazi Abdullah; Qadri, Ishtiaq

    2016-01-01

    Nanomaterials are utilized in a wide array of end user products such as pharmaceuticals, electronics, clothes and cosmetic products. Due to its size (< 100 nm), nanoparticles have the propensity to enter through the airway and skin, making its path perilous with the potential to cause damages of varying severity. Once within the body, these particles have unconstrained access to different tissues and organs including the brain, liver, and kidney. As a result, nanomaterials may cause the perturbation of the immune system eliciting an inflammatory response and cytotoxicity. This potential role is dependent on many factors such as the characteristics of the nanomaterials, presence or absence of diseases, and genetic predisposition. Cobalt and nickel nanoparticles, for example, were shown to have inflammogenic properties, while silver nanoparticles were shown to reduce allergic inflammation. Just as asbestos fibers, carbon nanotubes were shown to cause lungs damage. Some nanomaterials were shown, based on animal studies, to result in cell damage, leading to the formation of pre-cancerous lesions. This review highlights the impact of nanomaterials on immune system and its effect on human health with toxicity consideration. It recommends the development of suitable animal models to study the toxicity and bio-clearance of nanomaterials and propose safety guidelines. PMID:27398432

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

    Directory of Open Access Journals (Sweden)

    Jeongho Kim

    2016-01-01

    Full Text Available 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.

  18. 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)

    Kim, Jeongho; Yu, Il Je

    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.

  19. FOREWORD Nanomaterials science Nanomaterials science

    Science.gov (United States)

    Rohrer, Heinrich

    2010-10-01

    daring research proposal, even if it interprets 'nano' somewhat too generously. After all, we want to promote top-class research and not average research just for the sake of 'nano'. Interfaces, material growth at given nano positions, shaping materials to a given nanosize and form, and bistability are key elements for functionalizing materials. InterfacesThe role of interfaces is rapidly increasing in science and technology. The number of interfaces increases with the square of the number of phases of materials. Even if the majority of them are impractical or useless, they are still much more abundant than the materials themselves, and they are the key to new functions. Think of the simple 'mechanical' interface responsible for the lotus effect where wetting is prevented by the rapidly changing surface curvature due to nanoparticles. Think of all the connections of a nanometer-sized area between very different materials, for example, for electron or spin transport. Think of the delicate interfaces that protect nanofunctional units from the environment but allow for communication of various types with other nanocomponents or with the macroscopic world. The solid-liquid interface plays a special role here. For me, it is the interface of the future, both for local growth and removal of nm3 quantities and for working with biological specimens requiring a liquid environment. Interfaces are the 'faces of action' and nanoscale materials science will be, to a great extent, 'interface science'. There is no need to change the name; attentive awareness suffices. Material growth at given nano positionsThis is the second central challenge in nanoscale materials science, but maybe still a futuristic one. We have heard much about the extraordinary properties of carbon nanotubes. They do a great job in certain applications, like tips of scanning tunneling and atomic force microscopes or nanoinjection needles or as bundles for electron emission or electron transport. As single carbon

  20. Preparation of carbon-nitride bulk samples in the presence of seed carbon-nitride films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. I. [Korea University of Technology and Education, Chonan (Korea, Republic of); Zorov, N. B. [Moscow State University, Moscow (Russian Federation)

    2004-05-15

    A procedure was developed for preparing bulk carbon-nitride crystals from polymeric alpha-C{sub 3}N{sub 4.2} at high pressure and high temperature in the presence of seeds of crystalline carbon-nitride films prepared by using a high-voltage discharge plasma combined with pulsed laser ablation of a graphite target. The samples were evaluated by using X-ray photoelectron spectroscopy (XPS), infrared (IR) spectroscopy, Auger electron spectroscopy (AES), secondary-ion mass spectrometry (SIMS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Notably, XPS studies of the film composition before and after thermobaric treatments demonstrated that the nitrogen composition in the alpha-C{sub 3}N{sub 4.2} material, which initially contained more than 58 % nitrogen, decreased during the annealing process and reached a common, stable composition of approx 45 %. The thermobaric experiments were performed at 10 - 77 kbar and 350 - 1200 .deg. C.

  1. 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.

  2. 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...

  3. Synthesis and device applications of graphitic nanomaterials

    Science.gov (United States)

    Umair, Ahmad

    This thesis is focused on two topics: (i) synthesis and characterization of bilayer graphene and pyrolytic carbon by atmospheric pressure chemical vapor deposition, and (ii) application of graphene in the fabrication of a buckyball memory device. Monolayer and bilayer graphene are semi-metal with zero bandgap. One can induce a bandgap in bilayer graphene by applying a gate voltage in the stacking direction. Thus, bandgap and Fermi level in bilayer graphene can be controlled simultaneously with a double-gate device, making it a useful material for future semiconducting applications. Controlled synthesis of bilayer graphene would be the first step to fabricate bilayer graphene based devices. In this context, we report a uniform and low-defect synthesis of bilayer graphene on evaporated nickel films. Ultra-fast cooling is employed to control the number of layers and sample uniformity. The process is self-limiting, which leads to bilayer graphene synthesis over a wide range of growth-time and precursor flow-rate. Pryolytic carbon is another important carbon nanomaterial, due to its diverse applications in electronic and biomedicalengineering. We employ chemical vapor deposition with ultra-fast cooling technique to synthesize pyrolytic carbon. Furthermore, we elucidate a method to calculate the in-plane crystal size by using Raman spectroscopy. Finally, the use of bilayer graphene in a write-once read-many memory device has been demonstrated. The device showed irreversible switching from low-resistance to high-resistance state, with hysteresis in the transport characteristics. The control sample showed random switching and hysteresis due to electromigration of metal atoms into the active material of the device. We attribute the reliability and performance of the reported device to the ultra-smooth graphene contacts, which additionally inhibits electromigration from the underlying metallic film. Moreover, the memory device showed excellent endurance and retention

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

    Science.gov (United States)

    Wise, Kelsey; Brasuel, Murphy

    2011-01-01

    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.

  5. Nanomaterial-based biosensors for food toxin detection.

    Science.gov (United States)

    Malhotra, Bansi D; Srivastava, Saurabh; Ali, Md Azahar; Singh, Chandan

    2014-10-01

    There is an increased interest toward the development of bioelectronic devices for food toxin (mycotoxins) detection. Mycotoxins are highly toxic secondary metabolites produced by fungi like Fusarium, Aspergillus, and Penicillium that are frequently found in crops or during storage of food including cereals, nuts, fruits, etc. The contamination of food by mycotoxins has become a matter of increasing concern. High levels of mycotoxins in the diet can cause adverse, acute, and chronic effects on human health and a variety of animal species. Side effects may particularly affect the liver, kidney, nervous system, endocrine system, and immune system. Among 300 mycotoxins known till date, there are a few that are considered to play an important part in food safety, and for these, a range of analytical methods have been developed. Some of the important mycotoxins include aflatoxins, ochratoxins, fumonisins, citreoviridin, patulin, citrinin, and zearalenon. The conventional methods of analysis of mycotoxins normally require sophisticated instrumentation, e.g., liquid chromatography with fluorescence or mass detectors, combined with extraction procedures for sample preparation. Hence, new analysis tools are necessary to attain more sensitive, specific, rapid, and reliable information about the desired toxin. For the last about two decades, the research and development of simpler and faster analytical procedures based on affinity biosensors has aroused much interest due to their simplicity and sensitivity. The nanomaterials have recently had a great impact on the development of biosensors. The functionalized nanomaterials are used as catalytic tools, immobilization platforms, or as optical or electroactive labels to improve the biosensing performance to obtain higher sensitivity, stability, and selectivity. Nanomaterials, such as carbon nanomaterials (carbon nanotubes and graphene), metal nanoparticles, nanowires, nanocomposites, and nanostructured metal oxide nanoparticles

  6. 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

  7. 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

  8. 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...... into how the design of nanomaterials can be optimized to minimize their toxicity while still preserving their beneficial or wanted properties. Current efforts in this field are focusing on identifying design rules or parameters that can be adjusted to obtain a risk reduction, either by reducing the hazard...... 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...

  9. Nanomaterials and Nanochemistry

    CERN Document Server

    Bréchignac, Catherine; Lahmani, Marcel

    2007-01-01

    Nanomaterials are a fast developing field of research and applications lie in many separate domains, such as in hi-tech (optics, electronics, biology, aeronautics), but also in consumer industries (automotive, concrete, surface treatments (including paints), cosmetics, etc.).

  10. Potential risks of nanomaterials

    Science.gov (United States)

    Bakalova, Totka; Louda, Petr

    2014-05-01

    Nanotechnology is the design and manipulation of materials at the nanometer scale such that novel or enhanced properties emerge. It is a new area of knowledge that promises a dazzling array of opportunities in areas as diverse as manufacturing, energy, health care, and waste treatment. But while the ability to develop nanomaterials and incorporate them into products is advancing rapidly, our understanding of the potential environmental, health, and safety effects of nanomaterials — and of the most effective ways to manage such effects — has proceeded at a much slower pace. Because of the novel properties that emerge at the nano scale, nanomaterials may require more and different information than called for under traditional risk management systems. And given the enormous commercial and societal benefits that may potentially come from this technology, it is likely that nanomaterials, and the products and other applications containing them, will be widely produced and used. Therefore it is especially important to understand and minimize the potential risks.

  11. Food decontamination using nanomaterials

    Science.gov (United States)

    The research indicates that nanomaterials including nanoemulsions are promising decontamination media for the reduction of food contaminating pathogens. The inhibitory effect of nanoparticles for pathogens could be due to deactivate cellular enzymes and DNA; disrupting of membrane permeability; and/...

  12. Characterization of nanomaterials

    International Nuclear Information System (INIS)

    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.

  13. Center for Functional Nanomaterials

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for Functional Nanomaterials (CFN) explores the unique properties of materials and processes at the nanoscale. The CFN is a user-oriented research center...

  14. 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...

  15. NANOMATERIALS AND COSMETICS

    OpenAIRE

    E. ALĞIN YAPAR1,*, Ö. İNAL2, E. ALĞIN YAPAR1,*, Ö. İNAL2

    2014-01-01

    SUMMARYThis review has overviewed the nanotechnology approaches and safety concerns in cosmetics. Nanotechnology based nanomaterials have been widely use in cosmetics for recent few years such as in sunscreens, hair products, skincare products, etc. However debate on their definition and insufficient quantification methods are major problems still occur in the nanomaterial field. Moreover the frequent use of cosmetics, safety of nanoscale ingredients of them has gain importance mainly by mean...

  16. Energetics of Nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Alexandra Navrotsky; Brian Woodfield; Juliana Boerio-Goates; Frances Hellman

    2005-01-28

    This project, "Energetics of Nanomaterials," represents a three-year collaboration among Alexandra Navrotsky (UC Davis), Brian Woodfield and Juliana Boerio-Goates (BYU), and Frances Hellman (UC Berkeley). It's purpose has been to explore the differences between bulk materials, nanoparticles, and thin films in term of their thermodynamic properties, with an emphasis on heat capaacities and entropies, as well as enthalpies. the three groups have brought very different expertise and capabilities to the project. Navrotsky is a solid-state chemist and geochemist, with a unique Thermochemistry Facility emphasizing enthalpy of formation measurements by high temperature oxide melt and room temperatue acid solution calorimetry. Boerio-Goates and Woodfield are calorimetry. Hellman is a physicist with expertise in magnetism and heat capacity measurements using microscale "detector on a chip" calorimetric technology that she pioneered. The overarching question of our work is "How does the free energy play out in nanoparticles?", or "How do differences in free energy affect overall nanoparticle behavior?" Because the free energy represents the temperature-dependent balance between the enthalpy of a system and its entropy, there are two separate, but related, components to the experimental investigations: Solution calorimetric measurements provide the energetics and two types of heat capacity measurements the entropy. We use materials that are well characterized in other ways (structurally, magnetically, and chemically), and samples are shared across the collaboration.

  17. 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.

  18. 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.

  19. Computational Studies about the Interactions of Nanomaterials with Proteins and their Impacts

    CERN Document Server

    An, Deyi; Li, Chunhua; Li, Jingyuan

    2015-01-01

    Intensive concerns about the biosafety of nanomaterials demand the systematic study of the mechanisms about their biological effects. Many biological effects can be attributed to the interaction of nanomaterials with protein and their impacts on protein function. On the other hand, nanomaterials exhibit the potential in a variety of biomedical applications, many of which also involve the direct interaction with protein. In this paper, we review some recent computational studies about this subject, especially the interaction of carbon and gold nanomaterials. Besides the hydrophobic and {\\pi}-stacking interactions, the interaction mode of carbon nanomaterials can be regulated by their functional groups. And the coating of gold nanomaterials also adjusts their interaction mode, in addition to the coordination interaction with cysteine's sulfur group and histidine's imidazole group. Moreover, nanomaterials can interact with multiple proteins and the impacts on protein activity are attributed to a wide spectrum of...

  20. Shape Fixing via Salt Recrystallization: A Morphology-Controlled Approach To Convert Nanostructured Polymer to Carbon Nanomaterial as a Highly Active Catalyst for Oxygen Reduction Reaction.

    Science.gov (United States)

    Ding, Wei; Li, Li; Xiong, Kun; Wang, Yao; Li, Wei; Nie, Yao; Chen, Siguo; Qi, Xueqiang; Wei, Zidong

    2015-04-29

    Herein, we report a "shape fixing via salt recrystallization" method to efficiently synthesize nitrogen-doped carbon material with a large number of active sites exposed to the three-phase zones, for use as an ORR catalyst. Self-assembled polyaniline with a 3D network structure was fixed and fully sealed inside NaCl via recrystallization of NaCl solution. During pyrolysis, the NaCl crystal functions as a fully sealed nanoreactor, which facilitates nitrogen incorporation and graphitization. The gasification in such a closed nanoreactor creates a large number of pores in the resultant samples. The 3D network structure, which is conducive to mass transport and high utilization of active sites, was found to have been accurately transferred to the final N-doped carbon materials, after dissolution of the NaCl. Use of the invented cathode catalyst in a proton exchange membrane fuel cell produces a peak power of 600 mW cm(-2), making this among the best nonprecious metal catalysts for the ORR reported so far. Furthermore, N-doped carbon materials with a nanotube or nanoshell morphology can be realized by the invented method.

  1. 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.

  2. Aggregation, Deposition and Release of Graphene Oxide Nanomaterials in the Aquatic Environment

    Science.gov (United States)

    Graphene is an atomically thin two dimensional carbon-based nanomaterial that is composed of a single layer of sp2 – hybridized carbon atoms as found in graphite.1, 2 Usage of graphene-based nanomaterials is increasing rapidly and these materials are predicted to be the most abun...

  3. Biological and Pharmaceutical Nanomaterials

    Science.gov (United States)

    Kumar, Challa S. S. R.

    2006-01-01

    This first comprehensive yet concise overview of all important classes of biological and pharmaceutical nanomaterials presents in one volume the different kinds of natural biological compounds that form nanomaterials or that may be used to purposefully create them. This unique single source of information brings together the many articles published in specialized journals, which often remain unseen by members of other, related disciplines. Covering pharmaceutical, nucleic acid, peptide and DNA-Chitosan nanoparticles, the book focuses on those innovative materials and technologies needed for the continued growth of medicine, healthcare, pharmaceuticals and human wellness. For chemists, biochemists, cell biologists, materials scientists, biologists, and those working in the pharmaceutical and chemical industries.

  4. Nanomaterials for Defense Applications

    Science.gov (United States)

    Turaga, Uday; Singh, Vinitkumar; Lalagiri, Muralidhar; Kiekens, Paul; Ramkumar, Seshadri S.

    Nanotechnology has found a number of applications in electronics and healthcare. Within the textile field, applications of nanotechnology have been limited to filters, protective liners for chemical and biological clothing and nanocoatings. This chapter presents an overview of the applications of nanomaterials such as nanofibers and nanoparticles that are of use to military and industrial sectors. An effort has been made to categorize nanofibers based on the method of production. This chapter particularly focuses on a few latest developments that have taken place with regard to the application of nanomaterials such as metal oxides in the defense arena.

  5. Research on determining organic carbon in rock and mineral samples by gas chromatography

    International Nuclear Information System (INIS)

    The authors introduce results of research on transformation mechanism, temperature and time of organic carbon during analysis of rock and mineral samples by gas chromatography, as well as conditions for eliminating carbonate constituent that may produce carbon dioxide gas. The research has solved the problem of connecting the chemical processing and instrument determination. The newly-established method is characterized by high sensitivity, good exactitude, simple and fast operation, and may be applied to the determination of organic carbon in rock, mineral, as well as sediment samples

  6. Magnetic Nanomaterials and Their Applications

    Directory of Open Access Journals (Sweden)

    Yurii K. Gun'ko

    2014-06-01

    Full Text Available This Special Issue of Nanomaterials is dedicated to the development of new magnetic nanomaterials and their applications in biomedicine, catalysis, spintronics and other areas. The publications in this Issue demonstrate that the interest in magnetic nanomaterials is continuously growing and their realm is expanding rapidly. Some highlights of the publications in this issue are discussed below. [...

  7. Asphalt in carbon-14-dated archaeological samples from Terqa, Syria

    International Nuclear Information System (INIS)

    The results are reported of an organic geochemical study to verify contamination in 14C dated archaeological samples, which could account for much older apparent ages than expected. The data indicate that ancient asphalt must be the source of contamination, showing that caution should be exercised, in interpreting 14C dates of archaeological samples from areas containing asphalt or other fossil fuel deposits. (U.K.)

  8. Analysis of Dielectric and Electro-optic Responses of Nanomaterials Doped Ferroelectric Liquid Crystal Mixture

    Institute of Scientific and Technical Information of China (English)

    Neeraj; Pankaj Kumar; K.K. Raina

    2011-01-01

    Dielectric and rotational viscosity measurements of a multi-component ferroelectric liquid crystal mixture were performed by adding a small concentration (0.01 wt%) of silica and multi walled carbon nanotubes (MWCNTs). Liquid crystals turn out to be outstanding hosts for nanomaterials. A remarkable increase in the rotational viscosity was noticed in CNT doped system as compared to silica doped same liquid crystal system. Comparison of dielectric studies shows higher value of permittivity and dielectric losses for silica-doped sample than those of CNT doped sample. The results have been interpreted both experimentally and theoretically.

  9. Manipulation and behavior modeling of one-dimensional nanomaterials on a structured surface

    International Nuclear Information System (INIS)

    Different diameters of multiwall carbon nanotubes (CNTs) are manipulated by a cantilever tip of an atomic force microscope (AFM) to investigate the motion properties of one-dimensional nanomaterials on a structured surface. To describe the mechanical behaviors of this kind of samples, two mechanical models based on continuum mechanics are proposed. Through foreseeable manipulation procedures, we are able to position the tubes onto pre-etched micro trenches, and then measure their Young's moduli by the three-point bending method. Both string-like and beam-like deformation forms are observed on the tested samples. Additionally, we present a reparable 'collapse' phenomenon of the nanotube bridges.

  10. Nano-materials for adhesive-free adsorbers for bakable extreme high vacuum cryopump surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stutzman, Marcy; Jordan, Kevin; Whitney, Roy R.

    2016-10-11

    A cryosorber panel having nanomaterials used for the cryosorption material, with nanomaterial either grown directly on the cryopanel or freestanding nanomaterials attached to the cryopanel mechanically without the use of adhesives. Such nanomaterial cryosorber materials can be used in place of conventional charcoals that are attached to cryosorber panels with special low outgassing, low temperature capable adhesives. Carbon nanotubes and other nanomaterials could serve the same purpose as conventional charcoal cryosorbers, providing a large surface area for cryosorption without the need for adhesive since the nanomaterials can be grown directly on a metallic substrate or mechanically attached. The nanomaterials would be capable of being fully baked by heating above 100.degree. C., thereby eliminating water vapor from the system, eliminating adhesives from the system, and allowing a full bake of the system to reduce hydrogen outgassing, with the goal of obtaining extreme high vacuum where the pump can produce pressures below 1.times.10.sup.-12 Torr.

  11. Photocatalyst Nanomaterials for Environmental Challenges and Opportunities

    OpenAIRE

    Koo Y; Collins B; Sankar J; Yun Y

    2012-01-01

    Climate change caused by fossil-fuel use and other natural causes as well as Western and Asian economic growth driven by excessive consumption is among the biggest environmental challenges of the 21st century. Advances in nanotechnology bring a new tool set to remediate environmental challenges such as pollutant removal, anti-terror, air/liquid/soil filtration, and carbon dioxide conversion to hydrocarbons. As innovative engineered nanomaterials emerge, it is ...

  12. Toxicity of nanomaterials

    NARCIS (Netherlands)

    Sharifi, Shahriar; Behzadi, Shahed; Laurent, Sophie; Forrest, M. Laird; Stroeve, Pieter; Mahmoudi, Morteza

    2012-01-01

    Nanoscience has matured significantly during the last decade as it has transitioned from bench top science to applied technology. Presently, nanomaterials are used in a wide variety of commercial products such as electronic components, sports equipment, sun creams and biomedical applications. There

  13. Applications of Nanomaterials in Electrogenerated Chemiluminescence Biosensors

    Directory of Open Access Journals (Sweden)

    Honglan Qi

    2009-01-01

    Full Text Available Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. ECL biosensor, combining advantages offered by the selectivity of the biological recognition elements and the sensitivity of ECL technique, is a powerful device for ultrasensitive biomolecule detection and quantification. Nanomaterials are of considerable interest in the biosensor field owing to their unique physical and chemical properties, which have led to novel biosensors that have exhibited high sensitivity and stability. Nanomaterials including nanoparticles and nanotubes, prepared from metals, semiconductor, carbon or polymeric species, have been widely investigated for their ability to enhance the efficiencies of ECL biosensors, such as taking as modification electrode materials, or as carrier of ECL labels and ECL-emitting species. Particularly useful application of nanomaterials in ECL biosensors with emphasis on the years 2004-2008 is reviewed. Remarks on application of nanomaterials in ECL biosensors are also surveyed.

  14. Nitrogen, carbon, and sulfur metabolism in natural Thioploca samples

    DEFF Research Database (Denmark)

    Otte, S.; Kuenen, JG; Nielsen, LP;

    1999-01-01

    Filamentous sulfur bacteria of the genus Thioploca occur as dense mats on the continental shelf off the coast of Chile and Peru. Since little is known about their nitrogen, sulfur, and carbon metabolism, this study was undertaken to investigate their (eco)physiology. Thioploca is able to store...... internally high concentrations of sulfur globules and nitrate. It has been previously hypothesized that these large vacuolated bacteria can oxidize sulfide by reducing their internally stored nitrate. We examined this nitrate reduction by incubation experiments of washed Thioploca sheaths,vith trichomes in......) mg of protein(-1). The ammonium and sulfate production rates were not influenced by the addition of sulfide, suggesting that sulfide is first oxidized to elemental sulfur, and in a second independent step elemental sulfur is oxidized to sulfate. The average sulfide oxidation rate measured was 5 nmol...

  15. 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.

  16. Interaction of engineered nanomaterials with hydrophobic organic pollutants.

    Science.gov (United States)

    Sahle-Demessie, E; Han, Changseok; Zhao, Amy; Hahn, Bill; Grecsek, Heidi

    2016-07-15

    As nanomaterials become an increasing part of everyday consumer products, it is imperative to monitor their potential release during production, use and disposal, and to assess their impact on the health of humans and the ecosystem. This necessitates research to better understand how the properties of engineered nanomaterials (ENMs) lead to their accumulation and redistribution in the environment, and to assess whether they could become novel pollutants or if they can affect the mobility and bioavailability of other toxins. This study focuses on understanding the influence of nanostructured-TiO2 and the interaction of multi-walled carbon nanotubes with organic pollutants in water. We studied the adsorption and water phase dispersion of model pollutants with relatively small water solubility (i.e., two- and three-ring polyaromatic hydrocarbons and insecticides) with respect to ENMs. The sorption of pollutants was measured based on water phase analysis, and by separating suspended particles from the water phase and analyzing dried samples using integrated thermal-chromatographic-mass spectroscopic (TGA/GC/MS) techniques. Solid phase analysis using a combination of TGA/GC/MS is a novel technique that can provide real-time quantitative analysis and which helps to understand the interaction of hydrophobic organic pollutants and ENMs. The adsorption of these contaminants to nanomaterials increased the concentration of the contaminants in the aqueous phase as compared to the 'real' partitioning due to the octanol-water partitioning. The study showed that ENMs can significantly influence the adsorption and dispersion of hydrophobic/low water soluble contaminants. The type of ENM, the exposure to light, and the water pH have a significant influence on the partitioning of pollutants. PMID:27265536

  17. Interaction of engineered nanomaterials with hydrophobic organic pollutants

    Science.gov (United States)

    Sahle-Demessie, E.; Han, Changseok; Zhao, Amy; Hahn, Bill; Grecsek, Heidi

    2016-07-01

    As nanomaterials become an increasing part of everyday consumer products, it is imperative to monitor their potential release during production, use and disposal, and to assess their impact on the health of humans and the ecosystem. This necessitates research to better understand how the properties of engineered nanomaterials (ENMs) lead to their accumulation and redistribution in the environment, and to assess whether they could become novel pollutants or if they can affect the mobility and bioavailability of other toxins. This study focuses on understanding the influence of nanostructured-TiO2 and the interaction of multi-walled carbon nanotubes with organic pollutants in water. We studied the adsorption and water phase dispersion of model pollutants with relatively small water solubility (i.e., two- and three-ring polyaromatic hydrocarbons and insecticides) with respect to ENMs. The sorption of pollutants was measured based on water phase analysis, and by separating suspended particles from the water phase and analyzing dried samples using integrated thermal–chromatographic–mass spectroscopic (TGA/GC/MS) techniques. Solid phase analysis using a combination of TGA/GC/MS is a novel technique that can provide real-time quantitative analysis and which helps to understand the interaction of hydrophobic organic pollutants and ENMs. The adsorption of these contaminants to nanomaterials increased the concentration of the contaminants in the aqueous phase as compared to the ‘real’ partitioning due to the octanol–water partitioning. The study showed that ENMs can significantly influence the adsorption and dispersion of hydrophobic/low water soluble contaminants. The type of ENM, the exposure to light, and the water pH have a significant influence on the partitioning of pollutants.

  18. E-DNA sensor of Mycobacterium tuberculosis based on electrochemical assembly of nanomaterials (MWCNTs/PPy/PAMAM).

    Science.gov (United States)

    Miodek, Anna; Mejri, Nawel; Gomgnimbou, Michel; Sola, Christophe; Korri-Youssoufi, Hafsa

    2015-09-15

    Two-step electrochemical patterning methods have been employed to elaborate composite nanomaterials formed with multiwalled carbon nanotubes (MWCNTs) coated with polypyrrole (PPy) and redox PAMAM dendrimers. The nanomaterial has been demonstrated as a molecular transducer for electrochemical DNA detection. The nanocomposite MWCNTs-PPy has been formed by wrapping the PPy film on MWCNTs during electrochemical polymerization of pyrrole on the gold electrode. The MWCNTs-PPy layer was modified with PAMAM dendrimers of fourth generation (PAMAM G4) with covalent bonding by electro-oxidation method. Ferrocenyl groups were then attached to the surface as a redox marker. The electrochemical properties of the nanomaterial (MWCNTs-PPy-PAMAM-Fc) were studied using both square wave voltammetry and cyclic voltammetry to demonstrate efficient electron transfer. The nanomaterial shows high performance in the electrochemical detection of DNA hybridization leading to a variation in the electrochemical signal of ferrocene with a detection limit of 0.3 fM. Furthermore, the biosensor demonstrates ability for sensing DNA of rpoB gene of Mycobacterium tuberculosis in real PCR samples. Developed biosensor was suitable for detection of sequences with a single nucleotide polymorphism (SNP) T (TCG/TTG), responsible for resistance of M. tuberculosis to rifampicin drug, and discriminating them from wild-type samples without such mutation. This shows potential of such systems for further application in pathogens diagnostic and therapeutic purpose. PMID:26313137

  19. Presence in, and release of, nanomaterials from consumer products.

    Science.gov (United States)

    Yang, Yu; Westerhoff, Paul

    2014-01-01

    Widespread use of engineered nanomaterials (ENMs) in consumer products has led to concerns about their potential impact on humans and the environment. In order to fully assess the impacts and release of ENMs from consumer products, this chapter provides an overview of the types of consumer products that contain nanomaterials, the potential release mechanisms of these ENMs from consumer products, and the associated human exposure. Information from two large datasets on consumer goods associated with ENMs, namely, the U.S.-based Project for Emerging Nanotechnologies from the Woodrow Wilson International Center, and the European-based National Institute for Public Health and the Environment of Netherlands, have been summarized. These databases reveal that silver, titanium, carbon-based ENMs are the major nanomaterials associated with consumer products. The presence and potential release of silver, titanium, carbon-based, and other nanomaterials from consumer goods available in published literature are also summarized, as well as the potential human exposure scenarios of inhalation, ingestion, dermal, and combination of all means. The prospecting of nanomaterial in water and biosolids provides further evidence of ENM occurrence, which could be linked to the use of nanomaterials containing consumer goods. Finally, this overview provides guidelines on toxicity studies, which calls for further efforts to analyze the biological effects of ENMs on human beings and their exposure pathways in consumer products.

  20. Open tube combustion method of organic samples for stable carbon isotope analysis.

    Science.gov (United States)

    Velivetskaya, Tatiana A; Ignatyev, Alexander V; Reize, Marina V; Kiyashko, Serguei I

    2007-01-01

    A simple and effective method for the conversion of organic carbon into carbon dioxide for analysis of stable carbon isotopes (delta(13)C) in samples of various organic substances, soils, sedimentary rocks, oils and volatile organic liquids is presented. The conversion of organic carbon of the samples is carried out in a quartz reactor connected to a vacuum line for CO(2) freezing and purification. A solid organic sample mixed with CuO is placed at the reactor bottom and the reactor is subsequently filled with granular CuO. One end of the CuO column is preheated to 850 degrees C while the other end of the column in contact with the sample is kept at ambient temperature. Heating of the sample (850 degrees C) and the remainder of the column is then performed. The preheated part of the column provides efficient conversion of carbon into CO(2). The reactor for the conversion of volatile liquid organic compounds is filled with granular CuO. The column of CuO is heated to 850 degrees C. Samples of volatile liquids are introduced into the reactor through a septum using a microsyringe. Complete conversion takes 10 min for solid samples and 3 min for volatile liquids. The precision of the delta(13)C analysis for solid and volatile liquid organic substances is +/-0.1 per thousand and +/-0.04 per thousand, respectively.

  1. An Overview of Nanomaterials for Water and Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Haijiao Lu

    2016-01-01

    Full Text Available Due to the exceptional characteristics which resulted from nanoscale size, such as improved catalysis and adsorption properties as well as high reactivity, nanomaterials have been the subject of active research and development worldwide in recent years. Numerous studies have shown that nanomaterials can effectively remove various pollutants in water and thus have been successfully applied in water and wastewater treatment. In this paper, the most extensively studied nanomaterials, zero-valent metal nanoparticles (Ag, Fe, and Zn, metal oxide nanoparticles (TiO2, ZnO, and iron oxides, carbon nanotubes (CNTs, and nanocomposites are discussed and highlighted in detail. Besides, future aspects of nanomaterials in water and wastewater treatment are discussed.

  2. Environmental behavior of engineered nanomaterials in porous media: a review.

    Science.gov (United States)

    Park, Chang Min; Chu, Kyoung Hoon; Heo, Jiyong; Her, Namguk; Jang, Min; Son, Ahjeong; Yoon, Yeomin

    2016-05-15

    A pronounced increase in the use of nanotechnology has resulted in nanomaterials being released into the environment. Environmental exposure to the most common engineered nanomaterials (ENMs), such as carbon-based and metal-based nanomaterials, can occur directly via intentional injection for remediation purposes, release during the use of nanomaterial-containing consumer goods, or indirectly via different routes. Recent reviews have outlined potential risks assessments, toxicity, and life cycle analyses regarding ENM emission. In this review, inevitable release of ENMs and their environmental behaviors in aqueous porous media are discussed with an emphasis on influencing factors, including the physicochemical properties of ENMs, solution chemistry, soil hydraulic properties, and soil matrices. Major findings of laboratory column studies and numerical approaches for the transport of ENMs are addressed, and studies on the interaction between ENMs and heavy metal ions in aqueous soil environments are examined. Future research is also presented with specific research directions and outlooks. PMID:26882524

  3. Nanomaterials and nanofabrication for biomedical applications

    Science.gov (United States)

    Cheng, Chao-Min; Chia-Wen Wu, Kevin

    2013-08-01

    carriers (e.g. polymers, gold nanoparticles, Prussian blue nanoparticles, mesoporous silica nanoparticles and carbon-based nanomaterials). Here, we would like to show our deep appreciation to all authors and reviewers. Without their great help and contributions, this focus issue, including the review and original papers, would not have been published on schedule. This focus issue may not cover all issues in this emerging scientific field; however, we believe that our efforts have great potential 'to hurl a boulder to draw a jade' and ignite innovation and challenging discussion in the relevant scientific communities.

  4. Nanomaterials in ecotoxicology

    DEFF Research Database (Denmark)

    Scott-Fordsmand, Janeck James; Krogh, Paul Henning; Lead, Jamie M

    2008-01-01

    In ecotoxicology, a problem exists of quantifying real exposure and corresponding effects, especially in complex environments such as the soil. Hence, for a given total soil concentration to which the organism is exposed, the effect level depends on the available fraction and the chemical status...... ion activity models (FlAM) and biotic ligand models (BLM). Quantification and characterization of actual exposure is also of concern for nanomaterial and nanoparticle (NP) terrestrial ecotoxicology...

  5. β-Cyclodextrin anchoring onto pericarpium granati-derived magnetic mesoporous carbon for selective capture of lopid in human serum and pharmaceutical wastewater samples.

    Science.gov (United States)

    Liu, Rui-Lin; Zhang, Zhi-Qi; Jing, Wang-Hui; Wang, Lu; Luo, Zhi-Min; Chang, Rui-Miao; Zeng, Ai-Guo; Du, Wei; Chang, Chun; Fu, Qiang

    2016-05-01

    Functionalized magnetic carbonaceous nanomaterials, which are important materials with many practical and research applications in biomedical, pharmaceutical and biological fields, have recently attracted much attention. In this study, a magnetic mesoporous carbon coated with β-cyclodextrin (MMC@β-CD) was synthesized for the first time from natural pericarpium granati (PG). The as-obtained MMC@β-CD has high surface areas (203 m(2)g(-1)), large pore volumes (0.16 cm(3)g(-1)), relatively broad mesoporous sizes (6.8 nm) and a high saturation magnetization of 26.2 emu g(-1), which is sufficient for magnetic separation by an external magnetic field. The MMC@β-CD was used as an innovative adsorbent for magnetic solid-phase extraction of lopid via host-guest interaction prior to spectrofluorometric analysis. The proposed method was successfully applied to analyze lopid in human serum and pharmaceutical wastewater samples with recoveries in the range of 85.0-103.5% for the spiked samples. Overall, this work not only provides an inexpensive and eco-friendly method to fabricate MMC@β-CD (or MMC) from PG, but also develops a highly selective approach for capture of lopid in biological samples and environmental substances.

  6. 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.

  7. Characterization of Nanomaterials by Physical Methods

    Science.gov (United States)

    Rao, C. N. R.; Biswas, Kanishka

    2009-07-01

    Much progress in nanoscience and nanotechnology has been made in the past few years thanks to the increased availability of sophisticated physical methods to characterize nanomaterials. These techniques include electron microscopy and scanning probe microscopies, in addition to standard techniques such as X-ray and neutron diffraction, X-ray scattering, and various spectroscopies. Characterization of nanomaterials includes the determination not only of size and shape, but also of the atomic and electronic structures and other important properties. In this article we describe some of the important methods employed for characterization of nanostructures, describing a few case studies for illustrative purposes. These case studies include characterizations of Au, ReO3, and GaN nanocrystals; ZnO, Ni, and Co nanowires; inorganic and carbon nanotubes; and two-dimensional graphene.

  8. Energetics of Nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Frances

    2004-12-13

    This project, ''Energetics of Nanomaterials'', represents a three-year collaboration among Alexandra Navrotsky (University of California at Davis), Brian Woodfield and Juliana Boerio-Goates (Brigham Young University) and Frances Hellman (University of California at San Diego). Its purpose has been to explore the differences between bulk materials, nanoparticles, and thin films in terms of their thermodynamic properties, with an emphasis on heat capacities and entropies, as well as enthalpies. We used our combined experimental techniques to address the following questions: How does energy and entropy depend on particle size and crystal structure? Do entropic differences have their origins in changes in vibrational densities of states or configurational (including surface configuration) effects? Do material preparation and sample geometry, i.e., nanoparticles versus thin films, change these quantities? How do the thermodynamics of magnetic and structural transitions change in nanoparticles and thin films? Are different crystal structures stabilized for a given composition at the nanoscale, and are the responsible factors energetic, entropic, or both? How do adsorption energies (for water and other gases) depend on particle size and crystal structure in the nanoregime? What are the energetics of formation and strain energies in artificially layered thin films? Do the differing structures of grain boundaries in films and nanocomposites alter the energetics of nanoscale materials? Of the several directions we first proposed, we initially concentrated on a few systems: TiO(sub 2), CoO, and CoO-MgO. In these systems, we were able to clearly identify particle size-dependent effects on energy and vibrational entropy, and to separate out the effect of particle size and water content on the enthalpy of formation of the various TiO(sub 2) polymorphs. With CoO, we were able to directly compare nanoparticle films and bulk materials; this comparison is

  9. Center for Functional Nanomaterials (CFN)

    Data.gov (United States)

    Federal Laboratory Consortium — The CFN at Brookhaven National Laboratory focuses on understanding the chemical and physical response of nanomaterials to make functional materials such as sensors,...

  10. Synthesis, structural characterisation and antibacterial activity of Ag+-doped fluorapatite nanomaterials prepared by neutralization method

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • The neutralization method has been used for synthesis of silver-doped fluorapatite powders. • Particles of silver-doped fluorapatite samples are of nano size and homogenous in composition. • The Ag+-doped fluorapatite samples showed antibacterial effect against Kllebsiela pneumoniae, Staphylococcus aureus and Micrococcus luteus. • AFM studies showed that silver-doped sample causes considerable morphological changes of tested bacterial cells. - Abstract: Silver doped fluorapatite nanopowders were synthesised by neutralization method, which consists of dissolving Ag2O in solution of HF and H3PO4 and addition to suspension of Ca(OH)2. The powder XRD, SEM and FTIR studies indicated the formation of a fluorapatite nanomaterials with average length of the particles is about 80 nm and a width of about 15 nm. The FTIR studies show that carbonate content in samples is very small and carbonte ions substitute both phosphate and hydroxyl groups in the crystal structure of samples, forming AB-type fluorapatite. Antibacterial studies have demonstrated that all Ag+-doped fluorapatite samples exhibit bactericidal effect against pathogens: Staphylococcus aureus, Micrococcus luteus and Kllebsiela pneumoniae. Antibacterial activity increased with the increase of Ag+ in the samples. The atomic force microscopy studies revealed extensive damage to the bacterial cell envelops in the presence of Ag+-doped fluorapatite particles which may lead to their death. The synthesized Ag+-doped fluorapatite nanomaterials are promising as antibacterial biomaterials in orthopedics and dentistry

  11. Synthesis and Characterization of Bio-based Nanomaterials from Jabon (Anthocephalus cadamba (Roxb. Miq Wood Bark: an Organic Waste Material from Community Forest

    Directory of Open Access Journals (Sweden)

    Sutrisno

    2015-06-01

    Full Text Available The application of nanotechnology to produce nanomaterials from renewable bio-based materials, like wood bark, has great potential to benefit the wood processing industry. To support this issue, we investigated the production of bio-based nanomaterials using conventional balls milling. Jabon (Anthocephalus cadamba(Roxb. Miq wood bark (JWB, an organic waste material from a community forest was subjected to conventional balls milling for 96 h and was converted into bio-based nanomaterial. The morphology and particle size, chemical components, functional groups and crystallinity of the bio-based nanomaterial were evaluated using scanning electron microscopy (SEM, scanning electron microscopy extended with energy dispersive X-ray spectroscopy (SEM-EDS, Fourier transform infrared spectroscopy (FTIR, and X-ray diffraction (XRD. The particle-sizes obtained for the JWB bio-based nanomaterial were between 43 nm to 469 nm and the functional groups were detected as cellulose. The chemical components found were carbon, oxygen, chloride, potassium and calcium, except for the sample produced from sieve type T14, which did not contain chloride. The crystalline structure was calcium oxalate hydrate (C2CaO4.H2O with crystalline sizes 21 nm and 15 nm, produced from sieve types T14 and T200 respectively.

  12. Energy-filtered transmission electron microscopy of biological samples on highly transparent carbon nanomembranes

    CERN Document Server

    Rhinow, Daniel; Weber, Nils-Eike; Beyer, André; Gölzhäuser, Armin; Kühlbrandt, Werner; Hampp, Norbert; Turchanin, Andrey; 10.1016/j.ultramic.2011.01.028

    2011-01-01

    Ultrathin carbon nanomembranes (CNM) comprising crosslinked biphenyl precursors have been tested as support films for energy-filtered transmission electron microscopy (EFTEM) of biological specimens. Due to their high transparency CNM are ideal substrates for electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) of stained and unstained biological samples. Virtually background-free elemental maps of tobacco mosaic virus (TMV) and ferritin have been obtained from samples supported by ~ 1 nm thin CNM. Furthermore, we have tested conductive carbon nanomembranes (cCNM) comprising nanocrystalline graphene, obtained by thermal treatment of CNM, as supports for cryoEM of ice-embedded biological samples. We imaged ice-embedded TMV on cCNM and compared the results with images of ice-embedded TMV on conventional carbon film (CC), thus analyzing the gain in contrast for TMV on cCNM in a quantitative manner. In addition we have developed a method for the preparation of vitrified specimens, sus...

  13. Developing Korean Standard for Nanomaterial Exposure Assessment

    OpenAIRE

    Lee, Ji Hyun; Lee, Jun Yeob; Yu, Il Je

    2011-01-01

    Nanotechnology is now applied to many industries, resulting in wide range of nanomaterial-containing products, such as electronic components, cosmetic, medicines, vehicles, and home appliances. Nanoparticles can be released throughout the life cycle of nanoproducts, including the manufacture, consumer use, and disposal, thereby involving workers, consumers, and the environment in potential exposure. However, there is no current consensus on the best sampling method for characterizing manufact...

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

    Science.gov (United States)

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

    2015-12-01

    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. Project supported by the National Natural Science Foundation of China (Grant Nos. 21273240, 11204267, and 11474013).

  15. Electrocatalysis at metal nanomaterials

    Science.gov (United States)

    Dai, Lin

    Direct liquid fuel cells, such as direct methanol fuel cells and direct formic acid fuel cells, have attracted much attention in the past decades due to the need of clean and efficient power sources. One of the most critical issues in the development of highly efficient fuel cells is to increase the rates of fuel-cell reactions as a commercial product. As a result, the topic of electrocatalysis plays a significant role in the investigations of fuel cell reactions. For methanol oxidation, platinum based nanomaterials are the most important catalysts. For formic acid oxidation, both platinum and palladium based nanomaterials are widely employed as the catalysts. Recently, shape-control of the nanoparticles has become an imperative task due to the fact that most of the reactions in fuel cells are sensitive to the surface structure of the catalysts. Though numerous studies have been conducted in past to elucidate the catalytic activity on the nanomaterials with different shapes, the results are inconclusive. Herein, systematic comparison of catalytic activity toward methanol and formic acid oxidation on shape-controlled cubic platinum-based alloy nanoparticles with different alloy element are reported in this dissertation. Methanol and formic acid oxidation reactions on spherical and cubic Pt-Cu nanoparticles are also studied. Cu-Pd nanoparticles are synthesized through galvanic redox reactions to provide significantly higher and much more stable formic acid oxidation activities. Interparticle distance effect is investigated on two dimensional nanoparticle array electrodes with controlled particle size, which is ideal model system for exploring the interparticle distance effects on the voltammetric behavior and reaction mechanisms.

  16. Carbon-specific analysis of humic-like substances in atmospheric aerosol and precipitation samples.

    Science.gov (United States)

    Limbeck, Andreas; Handler, Markus; Neuberger, Bernhard; Klatzer, Barbara; Puxbaum, Hans

    2005-11-15

    A new approach for the carbon-specific determination of humic-like substances (HULIS) in atmospheric aerosols is presented. The method is based on a two-step isolation procedure of HULIS and the determination of HULIS carbon with a dissolved organic carbon analyzer. In the first step, a C18 solid-phase extraction is performed to separate HULIS from inorganic and hydrophilic organic sample constituents in aqueous sample solutions. The second isolation step is conducted on a strong anion exchanger to separate HULIS from remaining carbonaceous compounds. This ion chromatographic separation step including the subsequent on-line detection of HULIS carbon was performed fully automated to avoid the risk of sample contamination and to enhance the reproducibility of the method. With a 5-mL sample volume, a limit of detection of 1.0 mg C/L was obtained; this corresponds to an absolute amount of 5 microg of HULIS carbon. The reproducibility of the method given as the relative standard deviation was 4.3% (n = 10). The method was applied for the determination of water-soluble HULIS in airborne particulate matter. PM10 concentrations at an urban site in Vienna, Austria, ranged from around 0.1 to 1.8 microg of C/m(3) (n = 49); the fraction of water-soluble HULIS in OC was 12.1 +/- 7.2% (n = 49).

  17. Response of Heterogeneous and Fractured Carbonate Samples to CO2-Brine Exposure

    Science.gov (United States)

    Smith, M. M.; Mason, H. E.; Hao, Y.; Carroll, S.

    2014-12-01

    Carbonate rock units are often considered as candidate sites for storage of carbon dioxide (CO2), whether as stand-alone reservoirs or coupled with enhanced oil recovery efforts. In order to accept injected carbon dioxide, carbonate reservoirs must either possess sufficient preexisting connected void space, or react with CO2-acidified fluids to produce more pore space and improve permeability. However, upward migration of CO2 through barrier zones or seal layers must be minimized for effective safe storage. Therefore, prediction of the changes to porosity and permeability in these systems over time is a key component of reservoir management. Towards this goal, we present the results of several experiments on carbonate core samples from the Wellington, Kansas 1-32 well, conducted under reservoir temperature, pressure, and CO2 conditions. These samples were imaged by X-ray computed tomography (XRCT) and analyzed with nuclear magnetic resonance (NMR) spectroscopy both prior to and after reaction with CO2-enriched brines. The carbonate samples each displayed distinct responses to CO2 exposure in terms of permeability change with time and relative abundance of calcite versus dolomite dissolution. The measured permeability of each sample was also much lower than that estimated by downhole NMR logging, with samples with larger fractured regions possessing higher permeability values. We present also our modeling approach and preliminary simulation results for a specific sample from the targeted injection zone. The heterogeneous composition as well as the presence of large fractured zones within the rock necessitated the use of a nested three-region approach to represent the range of void space observed via tomography. Currently, the physical response to CO2-brine flow (i.e., pressure declines with time) is reproduced well but the extent of chemical reaction is overestimated by the model.

  18. Nanomaterials design and simulation

    CERN Document Server

    Balbuena, Perla

    2006-01-01

    Over the past few decades, several approaches have been developed for designing nano-structured or molecularly-structured materials. These advances have revolutionized practically all fields of science and engineering, providing an additional design variable, the feature size of the nano-structures, which can be tailored to provide new materials with very special characteristics. Nanomaterials: Design and Simulation explores the role that such advances have made toward a rational design of nanostructures and covers a variety of methods from ab initio electronic structure techniques, ab initio

  19. Thin films and nanomaterials

    International Nuclear Information System (INIS)

    The objective of this book is to disseminate the most recent research in Thin Films, Nanomaterials, Corrosion and Metallurgy presented at the International Conference on Advanced Materials (ICAM 2011) held in PSG College of Technology, Coimbatore, India during 12-16 December 2011. The book is a compilation of 113 chapters written by active researchers providing information and critical insights into the recent advancements that have taken place. Important new applications are possible today in the fields of microelectronics, opto-electronics, metallurgy and energy by the application of thin films on solid surfaces. Recent progress in high vacuum technology and new materials has a remarkable effect in thin film quality and cost. This has led to the development of new single or multi-layered thin film devices with diverse applications in a multitude of production areas, such as optics, thermal barrier coatings and wear protections, enhancing service life of tools and to protect materials against thermal and atmospheric influence. On the other hand, thin film process techniques and research are strongly related to the basic research activities in nano technology, an increasingly important field with countless opportunities for applications due to the emergence of new properties at the nanoscale level. Materials and structures that are designed and fabricated at the nano scale level, offer the potential to produce new devices and processes that may enhance efficiencies and reduce costs in many areas, as photovoltaic systems, hydrogen storage, fuel cells and solar thermal systems. In the book, the contributed papers are classified under two sections i) thin films and ii) nanomaterials. The thin film section includes single or multi layer conducting, insulating or semiconducting films synthesized by a wide variety of physical or chemical techniques and characterized or analyzed for different applications. The nanomaterials section deals with novel or exciting materials

  20. LCA of metal nanomaterial production

    DEFF Research Database (Denmark)

    Miseljic, Mirko; Diaz, Elsa Gabriela Alvarado; Olsen, Stig Irving

    The use of engineered nanomaterials (ENMs) in commercial product has reached a new stage, where consumers in their daily life are frequently encountered with products containing this new material class. Metal and metal-oxide nanomaterials are among the most commonly used ENMs in products. Potential...

  1. Selectivity and limitations of carbon sorption tubes for capturing siloxanes in biogas during field sampling.

    Science.gov (United States)

    Tansel, Berrin; Surita, Sharon C

    2016-06-01

    Siloxane levels in biogas can jeopardize the warranties of the engines used at the biogas to energy facilities. The chemical structure of siloxanes consists of silicon and oxygen atoms, alternating in position, with hydrocarbon groups attached to the silicon side chain. Siloxanes can be either in cyclic (D) or linear (L) configuration and referred with a letter corresponding to their structure followed by a number corresponding to the number of silicon atoms present. When siloxanes are burned, the hydrocarbon fraction is lost and silicon is converted to silicates. The purpose of this study was to evaluate the adequacy of activated carbon gas samplers for quantitative analysis of siloxanes in biogas samples. Biogas samples were collected from a landfill and an anaerobic digester using multiple carbon sorbent tubes assembled in series. One set of samples was collected for 30min (sampling 6-L gas), and the second set was collected for 60min (sampling 12-L gas). Carbon particles were thermally desorbed and analyzed by Gas Chromatography Mass Spectrometry (GC/MS). The results showed that biogas sampling using a single tube would not adequately capture octamethyltrisiloxane (L3), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). Even with 4 tubes were used in series, D5 was not captured effectively. The single sorbent tube sampling method was adequate only for capturing trimethylsilanol (TMS) and hexamethyldisiloxane (L2). Affinity of siloxanes for activated carbon decreased with increasing molecular weight. Using multiple carbon sorbent tubes in series can be an appropriate method for developing a standard procedure for determining siloxane levels for low molecular weight siloxanes (up to D3). Appropriate quality assurance and quality control procedures should be developed for adequately quantifying the levels of the higher molecular weight siloxanes in biogas with sorbent tubes

  2. Nanomaterials for biosensing applications: A Review

    Directory of Open Access Journals (Sweden)

    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.

  3. Nanomaterials for biosensing applications: A Review

    Science.gov (United States)

    Holzinger, Michael; Le Goff, Alan; Cosnier, Serge

    2014-08-01

    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.

  4. MAPLE deposition of nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Caricato, A.P., E-mail: annapaola.caricato@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Arima, V.; Catalano, M. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Cesaria, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Cozzoli, P.D. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Martino, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Taurino, A.; Rella, R. [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, I-73100 Lecce (Italy); Scarfiello, R. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Tunno, T. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Zacheo, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy)

    2014-05-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  5. IN SITU NON-INVASIVE SOIL CARBON ANALYSIS: SAMPLE SIZE AND GEOSTATISTICAL CONSIDERATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    WIELOPOLSKI, L.

    2005-04-01

    I discuss a new approach for quantitative carbon analysis in soil based on INS. Although this INS method is not simple, it offers critical advantages not available with other newly emerging modalities. The key advantages of the INS system include the following: (1) It is a non-destructive method, i.e., no samples of any kind are taken. A neutron generator placed above the ground irradiates the soil, stimulating carbon characteristic gamma-ray emission that is counted by a detection system also placed above the ground. (2) The INS system can undertake multielemental analysis, so expanding its usefulness. (3) It can be used either in static or scanning modes. (4) The volume sampled by the INS method is large with a large footprint; when operating in a scanning mode, the sampled volume is continuous. (5) Except for a moderate initial cost of about $100,000 for the system, no additional expenses are required for its operation over two to three years after which a NG has to be replenished with a new tube at an approximate cost of $10,000, this regardless of the number of sites analyzed. In light of these characteristics, the INS system appears invaluable for monitoring changes in the carbon content in the field. For this purpose no calibration is required; by establishing a carbon index, changes in carbon yield can be followed with time in exactly the same location, thus giving a percent change. On the other hand, with calibration, it can be used to determine the carbon stock in the ground, thus estimating the soil's carbon inventory. However, this requires revising the standard practices for deciding upon the number of sites required to attain a given confidence level, in particular for the purposes of upward scaling. Then, geostatistical considerations should be incorporated in considering properly the averaging effects of the large volumes sampled by the INS system that would require revising standard practices in the field for determining the number of spots to

  6. EMERGING MODALITIES FOR SOIL CARBON ANALYSIS: SAMPLING STATISTICS AND ECONOMICS WORKSHOP.

    Energy Technology Data Exchange (ETDEWEB)

    WIELOPOLSKI, L.

    2006-04-01

    The workshop's main objectives are (1) to present the emerging modalities for analyzing carbon in soil, (2) to assess their error propagation, (3) to recommend new protocols and sampling strategies for the new instrumentation, and, (4) to compare the costs of the new methods with traditional chemical ones.

  7. CARBONIZED FIBROUS RESIN AS A NEW SORBENT FOR SAMPLING POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN AMBIENT AIR

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new sampling method of ambient air analysis using carbonized fibrous resin as asorbent for polycyclic aromatic hydrocarbons (PAHs) was reported.The physical and chemical properties of the carbonized fibrous resins were measured. Thesample pretreatment with ultrasonic extraction and subsequent clean-up ehition through a silica gelcolumn was optimized. The suitable ultrasonic extraction conditions were selected as follows: resinweight was 1.5 g, ultrasonic extraction time 20 min, volume of extraction solvent 100 mi andextraction operation times 2~3. The concentrated extractable organic matter was submitted to nextstep of clean-up procedure of adsorption chromatography on silica gel column/n-hexane and amixture of dichloromethene:n-hexane solution 2:3 (v/v). The PAHs fractions in the real samplesfrom Changzhou, China were particularly analyzed using GC-MS data system and the data of massspectra, retention times and scan numbers of the real samples were compared with that of thestandards of 16 PAHs listed by the US EPA as "priority pollutants" of the environment. Theanalysis of the real samples indicates that the carbonized fibrous resin is a good sorbent. Thepretreatment of samples of ambient air with carbonized fibrous resin as a sorbent for P,AHs isproved to be reliable and might be used for the procedure of the determination of PAHs inatmospheric environment.

  8. Nanomechanics of Fiber-like Nanomaterials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Property characterization of nanomaterials is challenged by the small size of the structure because of the difficulties in manipulation. Here we demonstrate a novel approach that allows a direct measurement of the mechanical properties of individual nanotube-like structures by in-situ transmission electron microscopy(TEM).The technique is powerful in a way that it can directly correlate the atomic-scale microstructure of the carbon nanotube with its physical properties,providing a one-to-one correspondence in structure-property characterization. Applications of the technique will be demonstrated on mechanical properties, the electron field emission and the ballistic quantum conductance in individual nanotubes.

  9. Carbon nanoparticles trapped in vivo-similar to carbon nanotubes in time-dependent biodistribution.

    Science.gov (United States)

    Liu, Jia-Hui; Yang, Sheng-Tao; Wang, Xin; Wang, Haifang; Liu, Yamin; Luo, Pengju G; Liu, Yuanfang; Sun, Ya-Ping

    2014-08-27

    Carbon nanoparticles are in all of the carbon nanomaterials that are presently widely pursued for potential bioapplications, but their in vivo biodistribution-related properties are largely unknown. In this work, highly (13)C-enriched carbon nanoparticles were prepared to allow their quantification in biological samples by using isotope-ratio mass spectroscopy. The in vivo biodistribution results are presented and discussed, and also compared with those of the aqueous suspended carbon nanotubes reported previously. The distribution profile and time dependencies are largely similar between the nanoparticles and nanotubes, with results on both suggesting meaningful accumulation in some major organs over an extended period of time. Therefore, the surface modification of carbon nanoparticles, preferably the chemical functionalization of the nanoparticles with biocompatible molecules or species, is desirable or necessary in the pursuit of these nanomaterials for various bioapplications.

  10. Sampling protocol recommendations for measuring soil organic carbon stocks in the tropics

    Science.gov (United States)

    van Straaten, Oliver; Veldkamp, Edzo; Corre, Marife D.

    2013-04-01

    In the tropics, there is an urgent need for cost effective sampling approaches to quantify soil organic carbon (SOC) changes associated with land-use change given the lack of reliable data. The tropics are especially important considering the high deforestation rates, the huge belowground carbon pool and the fast soil carbon turnover rates. In the framework of a pan-tropic (Peru, Cameroon and Indonesia) land-use change study, some highly relevant recommendations on the SOC stocks sampling approaches have emerged. In this study, where we focused on deeply weathered mineral soils, we quantified changes in SOC stock following land-use change (deforestation and subsequent establishment of other land-uses). We used a space-for-time substitution sampling approach, measured SOC stocks in the top three meters of soil and compared recently converted land-uses with adjacent reference forest plots. In each respective region we investigated the most predominant land-use trajectories. In total 157 plots were established across the three countries, where soil samples were taken to a depth of three meters from a central soil pit and from the topsoil (to 0.5m) from 12 pooled composite samples. Finding 1 - soil depth: despite the fact that the majority of SOC stock from the three meter profile is found below one meter depth (50 to 60 percent of total SOC stock), the significant changes in SOC were only measured in the top meter of soil, while the subsoil carbon stock remained relatively unchanged by the land-use conversion. The only exception was for older (>50 yrs) cacao plantations in Cameroon where significant decreases were found below one meter. Finding 2 - pooled composite samples taken across the plot provided more spatially representative estimates of SOC stocks than samples taken from the central soil pit.

  11. Nanomaterials for renewable energy

    International Nuclear Information System (INIS)

    With demand for sustainable energy, resource, and environment protection, new material technologies are constantly expanding during the last few couple of decades. An intensive attention has been given by the scientific communities. In particular, nanomaterials are increasingly playing an active role either by increasing the efficiency of the energy storage and conversion processes or by improving the device design and performance. This special issue presents recent research advances in various aspects of energy storage technologies, advanced batteries, fuel cells, solar cell, biofuels, and so on. Design and synthesis of novel materials have demonstrated great impact on the utilization of the sustainable energy, which need to solve the increasing shortage of resource and the issues of environmental pollution

  12. Radiation damage tolerant nanomaterials

    Directory of Open Access Journals (Sweden)

    I.J. Beyerlein

    2013-11-01

    Full Text Available Designing a material from the atomic level to achieve a tailored response in extreme conditions is a grand challenge in materials research. Nanostructured metals and composites provide a path to this goal because they contain interfaces that attract, absorb and annihilate point and line defects. These interfaces recover and control defects produced in materials subjected to extremes of displacement damage, impurity implantation, stress and temperature. Controlling radiation-induced-defects via interfaces is shown to be the key factor in reducing the damage and imparting stability in certain nanomaterials under conditions where bulk materials exhibit void swelling and/or embrittlement. We review the recovery of radiation-induced point defects at free surfaces and grain boundaries and stabilization of helium bubbles at interphase boundaries and present an approach for processing bulk nanocomposites containing interfaces that are stable under irradiation.

  13. Biofunctionalization of Nanomaterials

    Science.gov (United States)

    Kumar, Challa S. S. R.

    2005-11-01

    The new book series 'Nanotechnologies for the Life Sciences' is the first comprehensive source on the topics where materials science and life sciences meet on the nanoscale. Each volume provides a concise overview of the underlying nanotechnologies for the design, creation and characterization of biomedical applications, collating the many articles found in the relevant specialized journals but as yet unseen by those working in other disciplines. Written by international experts describing the various facets of nanofabrication, the ten volumes of this single source of information cover the complete range of synthetic methods, tools and techniques being developed towards medical, biological and cybernetic applications. This volume covers the synthetic and materials aspects of instilling biocompatibility into nanomaterials with properties desirable for advanced medical and biological applications. Essential reading for anyone working in the various related disciplines: from medicine and biology through chemistry, materials science and physics to engineering.

  14. A novel approach to process carbonate samples for radiocarbon measurements with helium carrier gas

    International Nuclear Information System (INIS)

    Most laboratories prepare carbonates samples for radiocarbon analysis by acid decomposition in evacuated glass tubes and subsequent reduction of the evolved CO2 to graphite in self-made reduction manifolds. This process is time consuming and labor intensive. In this work, we have tested a new approach for the preparation of carbonate samples, where any high-vacuum system is avoided and helium is used as a carrier gas. The liberation of CO2 from carbonates with phosphoric acid is performed in a similar way as it is often done in stable isotope ratio mass spectrometry where CO2 is released with acid in septum sealed tube under helium atmosphere. The formed CO2 is later flushed in a helium flow by means of a double-walled needle mounted from the tubes to the zeolite trap of the automated graphitization equipment (AGE). It essentially replaces the elemental analyzer normally used for the combustion of organic samples. The process can be fully automated from sampling the released CO2 in the septum-sealed tubes with a commercially available auto-sampler to the graphitization with the automated graphitization. The new method yields in low sample blanks of about 50000 years. Results of processed reference materials (IAEA-C2, FIRI-C) are in agreement with their consensus values.

  15. Low Dimension Semiconducting Composite Nanomaterials

    Institute of Scientific and Technical Information of China (English)

    WANG Mang; CHEN Hong-zheng; SUN Jing-zhi

    2004-01-01

    Recently, low dimension nanostructures have gained considerable attention due to their technological potential as unique types of nanoscale building blocks for future optoelectronic devices and systems. Semiconducting composite nanomaterials, which can combine the advantages of two or more components, have been the focus in the area of nanomaterials synthesis and device application.In this paper, we report our work on the preparation of composite nanomaterials based on CNTs.CNTs were coated by organic or inorganic species via novel and facile methods (Fig. 1 and Fig.2).These functional CNTs based composites show eminent prospects and opportunities for new applications in a wide variation of areas.

  16. Characterization of biochar and bio-oil samples obtained from carbonization of various biomass materials

    Energy Technology Data Exchange (ETDEWEB)

    Oezcimen, Didem; Ersoy-Mericboyu, Ayseguel [Istanbul Technical University, Chemical-Metallurgical Engineering Faculty, Department of Chemical Engineering, Maslak 34469, Istanbul (Turkey)

    2010-06-15

    Apricot stone, hazelnut shell, grapeseed and chestnut shell are important biomass residues obtained from the food processing industry in Turkey and they have a great importance as being a source of energy. In this study, the characteristics of bio-oil and biochar samples obtained from the carbonization of apricot stone, hazelnut shell, grapeseed and chestnut shell were investigated. It was found that the biochar products can be characterized as carbon rich, high heating value and relatively pollution-free potential solid biofuels. The bio-oil products were also presented as environmentally friendly green biofuel candidates. (author)

  17. Palladium based nanomaterials for enhanced hydrogen spillover and storage

    Directory of Open Access Journals (Sweden)

    Suresh K. Konda

    2016-03-01

    Full Text Available Hydrogen storage remains one of the most challenging prerequisites to overcome toward the realization of a hydrogen based economy. The use of hydrogen as an energy carrier for fuel cell applications has been limited by the lack of safe and effective hydrogen storage materials. Palladium has high affinity for hydrogen sorption and has been extensively studied, both in the gas phase and under electrochemical conditions. In this review, recent advancements are highlighted and discussed in regard to palladium based nanomaterials for hydrogen storage, as well as the effects of hydrogen spillover on various adsorbents including carbons, metal organic frameworks, covalent organic frameworks, and other nanomaterials.

  18. Predictive modeling of nanomaterial exposure effects in biological systems

    Directory of Open Access Journals (Sweden)

    Liu X

    2013-09-01

    nanomaterials. Sample prediction models can be found at http://neiminer.i-a-i.com/nei_models. Conclusion: The EZ Metric-based data mining approach has been shown to have predictive power. The results provide valuable insights into the modeling and understanding of nanomaterial exposure effects. Keywords: nanomaterial exposure effects, biological response, toxicity, embryonic zebrafish, data mining, numerical prediction

  19. The impact of sampling techniques on soil pore water carbon measurements of an Icelandic Histic Andosol.

    Science.gov (United States)

    Sigfusson, Bergur; Paton, Graeme I; Gislason, Sigurdur R

    2006-10-01

    The carbon in soil pore water from a Histic Andosol from Western Iceland was studied at three different scales; in the field, in undisturbed outdoor mesocosms and in laboratory repacked microcosms. Pore water was extracted using suction cup lysimeters and hollow-fibre tube sampler devices (Rhizon samplers). There were significant differences in all measured variables, dissolved inorganic carbon (DIC), dissolved organic carbon (DOC) and pH values between the scales of the experiment. Gaseous constituents of soil solution and pH were more susceptible to changes in scale and the type of sampling devices used. Dissolved inorganic carbon concentrations did not differ significantly between field and mesocosm solutions but where up to 14 times lower in microcosms compared to mesocosms solutions. Rhizon samplers yielded solutions with up to 4.7 times higher DIC concentrations than porous cup lysimeters. Mesocosm surface horizon DOC concentrations were 20 and 2 times higher than in field and microcosms respectively. There was difference in DOC concentration between sampling methods (up to 8 times higher in suction cups than rhizon samplers) above 50 cm depth. Soil solution pH values did not differ between field and mesocosms and mesocosms and microcosms respectively down to 80 cm depth. Direct comparison between field and microcosms was not possible due to the nature of sampling devices. Soil solutions sampled with Rhizon samplers yielded lower pH values (up to 1.3 pH units) than those sampled with suction cups. Twenty percent of annually bound organic carbon at the soils surface under field conditions was lost by leaching of DOC and through decomposition to DIC in disturbed non-vegetated microcosms. This percentage increased to 38% in undisturbed vegetated mesocosms highlighting the importance of surface vegetation in importing carbon to soils. Increased influx of nutrients will increase growth and photosynthesis but decrease carbon sequestration in near surface horizons

  20. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    Science.gov (United States)

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-01

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering.

  1. Nanomaterials: Regulation and Risk Assessment

    DEFF Research Database (Denmark)

    Hansen, Steffen Foss; Grieger, Khara Deanne; Baun, Anders

    2013-01-01

    The topics of regulation and risk assessment of nanomaterials have never been more relevant and controversial in Europe than they are at this point in time. In this entry, we present and discuss a number of major pieces of legislation relevant for the regulation of nanomaterials, including REACH......, the Water Framework Directive, pharmaceuticals regulation, and the Novel Foods Regulation. Current regulation of nanomaterials entail three overall challenges: 1) limitations in regard to terminology and definitions of key terms such as a “substance,” “novel food,” etc.; 2) safety assessment requirements...... a number of limitations specific to nanomaterials, i.e., the fact that mass might not be the proper metric to describe the dose in dose–response assessment. These limitations are not easily overcome despite the fact that a lot of effort is being put into investigating the applicability of each...

  2. Regional Knowledge Production in Nanomaterials

    DEFF Research Database (Denmark)

    Grimpe, Christoph; Patuelli, Roberto

    2011-01-01

    Nanomaterials are seen as a key technology for the twenty-first century, and much is expected of them in terms of innovation and economic growth. They could open the way to many radically new applications, which would form the basis of innovative products. As nanomaterials are still...... distance being detrimental to the extent that spillovers can be realised. Due to the technological complexity, however, proximity could also be less important as relevant nanomaterials research is globally dispersed. Hence in this paper, we analyse the effects of co-location of R&D activities...... on nanomaterial patenting. Based on European Patent Office data at the German district level (NUTS-3), we estimate two negative binomial models in a knowledge production function framework and include a spatial filtering approach to adjust for spatial autocorrelation. Our results indicate...

  3. Nanomaterial-based electrochemical sensing of neurological drugs and neurotransmitters

    International Nuclear Information System (INIS)

    Nanomaterial-modified detection systems represent a chief driver towards the adoption of electrochemical methods, since nanomaterials enable functional tunability, ability to self-assemble, and novel electrical, optical and catalytic properties that emerge at this scale. This results in tremendous gains in terms of sensitivity, selectivity and versatility. We review the electrochemical methods and mechanisms that may be applied to the detection of neurological drugs. We focus on understanding how specific nano-sized modifiers may be applied to influence the electron transfer event to result in gains in sensitivity, selectivity and versatility of the detection system. This critical review is structured on the basis of the Anatomical Therapeutic Chemical (ATC) Classification System, specifically ATC Code N (neurotransmitters). Specific sections are dedicated to the widely used electrodes based on the carbon materials, supporting electrolytes, and on electrochemical detection paradigms for neurological drugs and neurotransmitters within the groups referred to as ATC codes N01 to N07. We finally discuss emerging trends and future challenges such as the development of strategies for simultaneous detection of multiple targets with high spatial and temporal resolutions, the integration of microfluidic strategies for selective and localized analyte pre-concentration, the real-time monitoring of neurotransmitter secretions from active cell cultures under electro- and chemotactic cues, aptamer-based biosensors, and the miniaturization of the sensing system for detection in small sample volumes and for enabling cost savings due to manufacturing scale-up. The Electronic Supporting Material (ESM) includes review articles dealing with the review topic in last 40 years, as well as key properties of the analytes, viz., pKa values, half-life of drugs and their electrochemical mechanisms. The ESM also defines analytical figures of merit of the drugs and neurotransmitters. The

  4. Nanomaterial-Enabled Dry Electrodes for Electrophysiological Sensing: A Review

    Science.gov (United States)

    Yao, Shanshan; Zhu, Yong

    2016-04-01

    Long-term, continuous, and unsupervised tracking of physiological data is becoming increasingly attractive for health/wellness monitoring and ailment treatment. Nanomaterials have recently attracted extensive attention as building blocks for flexible/stretchable conductors and are thus promising candidates for electrophysiological electrodes. Here we provide a review on nanomaterial-enabled dry electrodes for electrophysiological sensing, focusing on electrocardiography (ECG). The dry electrodes can be classified into contact surface electrodes, contact-penetrating electrodes, and noncontact capacitive electrodes. Different types of electrodes including their corresponding equivalent electrode-skin interface models and the sources of the noise are first introduced, followed by a review on recent developments of dry ECG electrodes based on various nanomaterials, including metallic nanowires, metallic nanoparticles, carbon nanotubes, and graphene. Their fabrication processes and performances in terms of electrode-skin impedance, signal-to-noise ratio, resistance to motion artifacts, skin compatibility, and long-term stability are discussed.

  5. 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...

  6. Nanomaterials for membranes and catalysts

    OpenAIRE

    Nassos, Stylianos

    2005-01-01

    Nanotechnology is a relatively new research topic that attracts increasing interest from scientists and engineers all over the world, due to its novel applications. The use of nanomaterials has extended to a broad range of applications, for example chemical synthesis, microporous media synthesis and catalytic combustion, contributing to achievement of improved or promising results. Microemulsion (ME) is considered a powerful tool for synthesis of nanomaterials, due to its unique properties. T...

  7. Plasma nanofabrication and nanomaterials safety

    International Nuclear Information System (INIS)

    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.

  8. [Comparative Sensitivity of the Luminescent Photobacterium phosphoreum, Escherichia coli, and Bacillus subtilis Strains to Toxic Effects of Carbon-Based Nanomaterials and Metal Nanoparticles].

    Science.gov (United States)

    Deryabina, D G; Efremova, L V; Karimov, I F; Manukhov, I V; Gnuchikh, E Yu; Miroshnikov, S A

    2016-01-01

    A comparative analysis of the four commercially available and laboratory luminescent sensor strains to the toxic effect of 10 carbon-based nanomatherials (CBNs) and 10 metal nanoparticles (MNPs) was carried out in this study. The bioluminescence inhibition assays with marine Photobacterium phosphoreum and recombinant Escherichia coli strains were varied in minimal toxic concentrations and EC50 values but led to well correlated biotoxicity evaluation for the most active compounds were ranked as Cu > (MgO, CuO) > (fullerenol, graphene oxide). The novel sensor strain Bacillus subtilis EG 168-1 exhibited the highest sensitivity to CBNs and MNPs that increased significantly number of toxic compounds causing the bacterial bioluminescence inhibition effect. PMID:27476206

  9. Deformable devices with integrated functional nanomaterials for wearable electronics

    Science.gov (United States)

    Kim, Jaemin; Lee, Jongsu; Son, Donghee; Choi, Moon Kee; Kim, Dae-Hyeong

    2016-03-01

    As the market and related industry for wearable electronics dramatically expands, there are continuous and strong demands for flexible and stretchable devices to be seamlessly integrated with soft and curvilinear human skin or clothes. However, the mechanical mismatch between the rigid conventional electronics and the soft human body causes many problems. Therefore, various prospective nanomaterials that possess a much lower flexural rigidity than their bulk counterparts have rapidly established themselves as promising electronic materials replacing rigid silicon and/or compound semiconductors in next-generation wearable devices. Many hybrid structures of multiple nanomaterials have been also developed to pursue both high performance and multifunctionality. Here, we provide an overview of state-of-the-art wearable devices based on one- or two-dimensional nanomaterials (e.g., carbon nanotubes, graphene, single-crystal silicon and oxide nanomembranes, organic nanomaterials and their hybrids) in combination with zero-dimensional functional nanomaterials (e.g., metal/oxide nanoparticles and quantum dots). Starting from an introduction of materials strategies, we describe device designs and the roles of individual ones in integrated systems. Detailed application examples of wearable sensors/actuators, memories, energy devices, and displays are also presented.

  10. STUDY OF DEPENDENCE OF POLYETHYLENE AND CARBON FIBERS COMPOSITES PROPERNIES ON SURFACE CHARACTERISTICS OF FIBER AND TYPE OF SAMPLES

    Directory of Open Access Journals (Sweden)

    Petukhova E. S.

    2015-06-01

    Full Text Available PE2NT11 and chopped carbon fibers and PE2NT11 and modified carbon fibers composites were investigated. It was shown that the mechanical properties depend on the surface characteristics of fibers. It was found that laboratory and tube samples have some difference in mechanical properties that connected with specific distribution of fibers in samples

  11. STUDY OF DEPENDENCE OF POLYETHYLENE AND CARBON FIBERS COMPOSITES PROPERNIES ON SURFACE CHARACTERISTICS OF FIBER AND TYPE OF SAMPLES

    OpenAIRE

    Petukhova E. S.

    2015-01-01

    PE2NT11 and chopped carbon fibers and PE2NT11 and modified carbon fibers composites were investigated. It was shown that the mechanical properties depend on the surface characteristics of fibers. It was found that laboratory and tube samples have some difference in mechanical properties that connected with specific distribution of fibers in samples

  12. Sampling and monitoring of carbon-14 in gaseous effluents from nuclear facilities

    International Nuclear Information System (INIS)

    This study reviews the possibilities from sampling and monitoring C-14 in gaseous effluents from nuclear facilities. After oxidation of various forms of carbon-14 in the off-gas into CO2 three main processes for trapping are used either separately or in combination. These are sorption, freezing and chemical processes. Absorption in alkaline solutions or solids or molecular sieve adsorption are the most frequently used methods. The main counting methods used are gas proportional counting and liquid scintillation counting

  13. Evidence of a bacterial carbonate coating on plaster samples subjected to the Calcite Bioconcept biomineralization technique

    OpenAIRE

    Anne, Séverinne; Rozenbaum, Olivier; Andreazza, Pascal; Rouet, Jean-Louis

    2010-01-01

    International audience Degradation of historical buildings is mainly due to the intrusion of water which is the main vector of pollutants. Different types of surface treatment have been proposed to avoid or limit this effect. One alternative to chemical treatments is the use of the carbonatogenesis property of some bacteria. This bacterial production has been evidenced on concrete and on limestone samples in an aqueous environment. However, the carbonate production was measured indirectly ...

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

    OpenAIRE

    Wise, Kelsey; Brasuel, Murphy

    2011-01-01

    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 cur...

  15. Applications of radiotracer techniques for the pharmacology and toxicology studies of nanomaterials

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZhiYong; ZHAO YuLiang; CHAI ZhiFang

    2009-01-01

    With the rapid development of nanosciences and nanotechnology, a wide variety of manufactured nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and in-dustries. While nanomaterials possess more novel and unique physicochemical properties than bulk materials, they also have an unpredictable impact on human health. In the pharmacology and toxicol-ogy studies of nanomaterials, it is essential to know the basic behavior in vivo, i.e. absorption, distri-bution, metabolism, and excretion (ADME) of these newly designed materials. Radiotracer techniques are especially well suited to such studies and have got the chance to demonstrate their enchantment.In this paper, radiolabeling methods for carbon nanomaterials, metallic and metal oxide nanoparticles,etc. are summarized and the applications of the radiolabeled nanomaterials in pharmacology and toxicology studies are outlined.

  16. Ionic liquid-assisted bidirectional regulation strategy for carbon quantum dots (CQDs)/Bi4O5I2 nanomaterials and enhanced photocatalytic properties.

    Science.gov (United States)

    Ji, Mengxia; Xia, Jiexiang; Di, Jun; Wang, Bin; Yin, Sheng; Xu, Li; Zhao, Junze; Li, Huaming

    2016-09-15

    In this study, novel visible-light-driven carbon quantum dots (CQDs)/Bi4O5I2 material has been prepared via a reactable ionic liquid 1-hexyl-3-methylimidazolium iodide ([Hmim]I) assisted bidirectional regulation solvothermal method. This is the first time for the preparation of CQDs/Bi4O5I2 material with halogen and CQDs bidirectional regulation at the same time. With CQDs modified on the surface of Bi4O5I2, fast transfer of photogenerated charges and low recombination of photo-induced electron-hole pairs facilitated the enhancement of photodegradation activity. At the same time, the introduction of CQDs made the electrons occupied in high-energy potential on the conduction band of Bi4O5I2 transfer to the reaction center CQDs and the molecular oxygen can be thus activated. The enhanced mechanisms for the active species (holes, hydroxyl and superoxide radicals) during the photocatalytic reaction under visible irradiation were analyzed using DRS analysis, electron spin resonance (ESR) technique and free radicals trapping experiments. PMID:27318012

  17. Effects of carbon nanomaterials fullerene C{sub 60} and fullerol C{sub 60}(OH){sub 18-22} on gills of fish Cyprinus carpio (Cyprinidae) exposed to ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Socoowski Britto, Roberta; Longaray Garcia, Marcia; Martins da Rocha, Alessandra [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil); Artigas Flores, Juliana [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Pinheiro, Mauricio V. Brant [Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, MG (Brazil); Monserrat, Jose Maria [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil); Ribas Ferreira, Josencler L., E-mail: josenclerf@gmail.com [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil)

    2012-06-15

    In consequence of their growing use and demand, the inevitable environmental presence of nanomaterials (NMs) has raised concerns about their potential deleterious effects to aquatic environments. The carbon NM fullerene (C{sub 60}), which forms colloidal aggregates in water, and its water-soluble derivative fullerol (C{sub 60}(OH){sub 18-22}), which possesses antioxidant properties, are known to be photo-excited by ultraviolet (UV) or visible light. To investigate their potential hazards to aquatic organisms upon exposure to UV sunlight, this study analyzed (a) the in vitro behavior of fullerene and fullerol against peroxyl radicals (ROO{center_dot}) under UV-A radiation and (b) the effects of these photo-excited NMs on oxidative stress parameters in functional gills extracted from the fish Cyprinus carpio (Cyprinidae). The variables measured were the total antioxidant capacity, lipid peroxidation (TBARS), the activities of the antioxidant enzymes glutathione reductase (GR) and glutamate cysteine ligase (GCL), and the levels of the non-enzymatic antioxidant glutathione (GSH). The obtained results revealed the following: (1) both NMs behaved in vitro as antioxidants against ROO{center_dot} in the dark and as pro-oxidants in presence of UV-A, the latter effect being reversed by the addition of sodium azide, which is a singlet oxygen ({sup 1}O{sub 2}) quencher; (2) fullerene induced toxicity with or without UV-A incidence, with a significant (p < 0.05) increase in lipid peroxidation (with greater damage under illumination), a decrease in GCL activity, and the depletion of GSH stocks (under illumination), all of which were attributed to {sup 1}O{sub 2} generation; and (3) fullerol also decreased GCL activity and GSH formation (p < 0.05) but without lipid damage. The overall results show that fullerene can be toxic with or without light incidence, whereas UV radiation seems to play a key role in the environmental toxicity of carbon NMs through {sup 1}O{sub 2} formation.

  18. Influence of Nanomaterial Compatibilization Strategies on Polyamide Nanocomposites Properties and Nanomaterial Release during the Use Phase.

    Science.gov (United States)

    Fernández-Rosas, Elisabet; Vilar, Gemma; Janer, Gemma; González-Gálvez, David; Puntes, Victor; Jamier, Vincent; Aubouy, Laurent; Vázquez-Campos, Socorro

    2016-03-01

    The incorporation of small amounts of nanofillers in polymeric matrices has enabled new applications in several industrial sectors. The nanofiller dispersion can be improved by modifying the nanomaterial (NM) surface or predispersing the NMs to enhance compatibility. This study evaluates the effect of these compatibilization strategies on migration/release of the nanofiller and transformation of polyamide-6 (PA6), a thermoplastic polymer widely used in industry during simulated outdoors use. Two nanocomposites (NCs) containing SiO2 nanoparticles (NPs) with different surface properties and two multiwalled carbon nanotube (MWCNT) NCs obtained by different addition methods were produced and characterized, before and after accelerated wet aging conditions. Octyl-modified SiO2 NPs, though initially more aggregated than uncoated SiO2 NPs, reduced PA6 hydrolysis and, consequently, NM release. Although no clear differences in dispersion were observed between the two types of MWCNT NCs (masterbatch vs direct addition) after manufacture, the use of the MWCNT masterbatch reduced PA6 degradation during aging, preventing MWCNT accumulation on the surface and further release or potential exposure by direct contact. The amounts of NM released were lower for MWCNTs (36 and 108 mg/m(2)) than for SiO2 NPs (167 and 730 mg/m(2)), being lower in those samples where the NC was designed to improve the nanofiller-matrix interaction. Hence, this study shows that optimal compatibilization between NM and matrix can improve NC performance, reducing polymer degradation and exposure and/or release of the nanofiller. PMID:26830469

  19. Quality assurance and quality control for thermal/optical analysis of aerosol samples for organic and elemental carbon.

    Science.gov (United States)

    Chow, Judith C; Watson, John G; Robles, Jerome; Wang, Xiaoliang; Chen, L-W Antony; Trimble, Dana L; Kohl, Steven D; Tropp, Richard J; Fung, Kochy K

    2011-12-01

    Accurate, precise, and valid organic and elemental carbon (OC and EC, respectively) measurements require more effort than the routine analysis of ambient aerosol and source samples. This paper documents the quality assurance (QA) and quality control (QC) procedures that should be implemented to ensure consistency of OC and EC measurements. Prior to field sampling, the appropriate filter substrate must be selected and tested for sampling effectiveness. Unexposed filters are pre-fired to remove contaminants and acceptance tested. After sampling, filters must be stored in the laboratory in clean, labeled containers under refrigeration (carbon analyses, periodic QC tests include calibration of the flame ionization detector with different types of carbon standards, thermogram inspection, replicate analyses, quantification of trace oxygen concentrations (helium atmosphere, and calibration of the sample temperature sensor. These established QA/QC procedures are applicable to aerosol sampling and analysis for carbon and other chemical components. PMID:21626190

  20. A 3-dimensional micro- and nanoparticle transport and filtration model (MNM3D) applied to the migration of carbon-based nanomaterials in porous media

    Science.gov (United States)

    Bianco, Carlo; Tosco, Tiziana; Sethi, Rajandrea

    2016-10-01

    Engineered nanoparticles (NPs) in the environment can act both as contaminants, when they are unintentionally released, and as remediation agents when injected on purpose at contaminated sites. In this work two carbon-based NPs are considered, namely CARBO-IRON®, a new material developed for contaminated site remediation, and single layer graphene oxide (SLGO), a potential contaminant of the next future. Understanding and modeling the transport and deposition of such NPs in aquifer systems is a key aspect in both cases, and numerical models capable to simulate NP transport in groundwater in complex 3D scenarios are necessary. To this aim, this work proposes a modeling approach based on modified advection-dispersion-deposition equations accounting for the coupled influence of flow velocity and ionic strength on particle transport. A new modeling tool (MNM3D - Micro and Nanoparticle transport Model in 3D geometries) is presented for the simulation of NPs injection and transport in 3D scenarios. MNM3D is the result of the integration of the numerical code MNMs (Micro and Nanoparticle transport, filtration and clogging Model - Suite) in the well-known transport model RT3D (Clement et al., 1998). The injection in field-like conditions of CARBO-IRON® (20 g/l) amended by CMC (4 g/l) in a 2D vertical tank (0.7 × 1.0 × 0.12 m) was simulated using MNM3D, and compared to experimental results under the same conditions. Column transport tests of SLGO at a concentration (10 mg/l) representative of a possible spill of SLGO-containing waste water were performed at different values of ionic strength (0.1 to 35 mM), evidencing a strong dependence of SLGO transport on IS, and a reversible blocking deposition. The experimental data were fitted using the numerical code MNMs and the ionic strength-dependent transport was up-scaled for a full scale 3D simulation of SLGO release and long-term transport in a heterogeneous aquifer. MNM3D showed to potentially represent a valid tool for

  1. Thin Films for Coating Nanomaterials

    Institute of Scientific and Technical Information of China (English)

    S.M.Mukhopadhyay; P.Joshi; R.V.Pulikollu

    2005-01-01

    For nano-structured solids (those with one or more dimensions in the 1-100 nm range), attempts of surface modification can pose significant and new challenges. In traditional materials, the surface coating could be several hundreds nanometers in thickness, or even microns and millimeters. In a nano-structured material, such as particle or nanofibers, the coating thickness has to be substantially smaller than the bulk dimensions (100 nm or less), yet be durable and effective. In this paper, some aspects of effective nanometer scale coatings have been discussed. These films have been deposited by a non-line of sight (plasma)techniques; and therefore, they are capable of modifying nanofibers, near net shape cellular foams, and other high porosity materials. Two types of coatings will be focused upon: (a) those that make the surface inert and (b) those designed to enhance surface reactivity and bonding. The former has been achieved by forming 1-2 nm layer of -CF2- (and/or CF3) groups on the surface, and the latter by creating a nanolayer of SiO2-type compound. Nucleation and growth studies of the plasma-generated film indicate that they start forming as 2-3 nm high islands that grow laterally, and eventually completely cover the surface with 2-3nm film. Contact angle measurements indicate that these nano-coatings are fully functional even before they have achieved complete coverage of 2-3 nm. They should therefore be applicable to nano-structural solids.This is corroborated by application of these films on vapor grown nanofibers of carbon, and on graphitic foams. Coated and uncoated materials are infiltrated with epoxy matrix to form composites and their microstructure, as well as mechanical behaviors are compared. The results show that the nano-oxide coating can significantly enhance bond formation between carbon and organic phases, thereby enhancing wettability,dispersion, and composite behavior. The fluorocarbon coating, as expected, reduces bond formation, and

  2. Electrochemically modified sulfisoxazole nanofilm on glassy carbon for determination of cadmium(II) in water samples

    International Nuclear Information System (INIS)

    Highlights: • Sulfisoxazole was grafted onto glassy carbon electrode. • The electrode was characterized by spectroscopic and electrochemical methods. • It has been used for the determination of Cd(II) ions in real samples in very low concentrations. -- Abstract: Sulfisoxazole (SO) was grafted to glassy carbon electrode (GCE) via the electrochemical oxidation of SO in acetonitrile solution containing 0.1 M tetrabutylammoniumtetra-fluoroborate (TBATFB). The prepared electrode was characterized by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), reflection–absorption infrared spectroscopy (RAIRS) and X-ray photoelectron spectroscopy (XPS). The ellipsometric thickness of SO nanofilm at the glassy carbon surface was obtained as 14.48 ± 0.11 nm. The stability of the SO modified GCE was studied. The SO modified GCE was also utilized for the determination of Cd(II) ions in water samples in the presence of Pb(II) and Fe(II) by adsorptive stripping voltammetry. The linearity range and the detection limit of Cd(II) ions were 1.0 × 10−10 to 5.0 × 10−8 M and 3.3 × 10−11 M (S/N = 3), respectively

  3. Uncertainties of size measurements in electron microscopy characterization of nanomaterials in foods

    DEFF Research Database (Denmark)

    Dudkiewicz, Agnieszka; Boxall, Alistair B. A.; Chaudhry, Qasim;

    2015-01-01

    Electron microscopy is a recognized standard tool for nanomaterial characterization, and recommended by the European Food Safety Authority for the size measurement of nanomaterials in food. Despite this, little data have been published assessing the reliability of the method, especially for size...... measurement of nanomaterials characterized by a broad size distribution and/or added to food matrices. This study is a thorough investigation of the measurement uncertainty when applying electron microscopy for size measurement of engineered nanomaterials in foods. Our results show that the number of measured...... particles was only a minor source of measurement uncertainty for nanomaterials in food, compared to the combined influence of sampling, sample preparation prior to imaging and the image analysis. The main conclusion is that to improve the measurement reliability, care should be taken to consider...

  4. Enrichment of diluted cell populations from large sample volumes using 3D carbon-electrode dielectrophoresis.

    Science.gov (United States)

    Islam, Monsur; Natu, Rucha; Larraga-Martinez, Maria Fernanda; Martinez-Duarte, Rodrigo

    2016-05-01

    Here, we report on an enrichment protocol using carbon electrode dielectrophoresis to isolate and purify a targeted cell population from sample volumes up to 4 ml. We aim at trapping, washing, and recovering an enriched cell fraction that will facilitate downstream analysis. We used an increasingly diluted sample of yeast, 10(6)-10(2) cells/ml, to demonstrate the isolation and enrichment of few cells at increasing flow rates. A maximum average enrichment of 154.2 ± 23.7 times was achieved when the sample flow rate was 10 μl/min and yeast cells were suspended in low electrically conductive media that maximizes dielectrophoresis trapping. A COMSOL Multiphysics model allowed for the comparison between experimental and simulation results. Discussion is conducted on the discrepancies between such results and how the model can be further improved. PMID:27375816

  5. Enrichment of diluted cell populations from large sample volumes using 3D carbon-electrode dielectrophoresis.

    Science.gov (United States)

    Islam, Monsur; Natu, Rucha; Larraga-Martinez, Maria Fernanda; Martinez-Duarte, Rodrigo

    2016-05-01

    Here, we report on an enrichment protocol using carbon electrode dielectrophoresis to isolate and purify a targeted cell population from sample volumes up to 4 ml. We aim at trapping, washing, and recovering an enriched cell fraction that will facilitate downstream analysis. We used an increasingly diluted sample of yeast, 10(6)-10(2) cells/ml, to demonstrate the isolation and enrichment of few cells at increasing flow rates. A maximum average enrichment of 154.2 ± 23.7 times was achieved when the sample flow rate was 10 μl/min and yeast cells were suspended in low electrically conductive media that maximizes dielectrophoresis trapping. A COMSOL Multiphysics model allowed for the comparison between experimental and simulation results. Discussion is conducted on the discrepancies between such results and how the model can be further improved.

  6. Voltammetric Determination of Ferulic Acid Using Polypyrrole-Multiwalled Carbon Nanotubes Modified Electrode with Sample Application

    Directory of Open Access Journals (Sweden)

    Refat Abdel-Hamid

    2015-10-01

    Full Text Available A polypyrrole-multiwalled carbon nanotubes modified glassy carbon electrode-based sensor was devised for determination of ferulic acid (FA. The fabricated sensor was prepared electrochemically using cyclic voltammetry (CV and characterized using CV and scanning electron microscope (SEM. The electrode shows an excellent electrochemical catalytic activity towards FA oxidation. Under optimal conditions, the anodic peak current correlates linearly to the FA concentration throughout the range of 3.32 × 10−6 to 2.59 × 10−5 M with a detection limit of 1.17 × 10−6 M (S/N = 3. The prepared sensor is highly selective towards ferulic acid without the interference of ascorbic acid. The sensor applicability was tested for total content determination of FA in a commercial popcorn sample and showed a robust functionality.

  7. 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...

  8. Engineered Nanomaterials Elicit Cellular Stress Responses

    Science.gov (United States)

    Engineered nanomaterials are being developed continuously and incorporated into consumer products, resulting in increased human exposures. The study of engineered nanomaterials has focused largely on toxicity endpoints without further investigating potential mechanisms or pathway...

  9. 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.

  10. Effectiveness of Micro- and Nanomaterials in Asphalt Mixtures through Dynamic Modulus and Rutting Tests

    OpenAIRE

    Hui Yao; Zhanping You

    2016-01-01

    The objectives of this research are to use micro- and nanomaterials to modify the asphalt mixture and to evaluate the mechanical performance of asphalt mixtures. These micro- and nanomaterials, including carbon microfiber, Nanomer material, nanosilica, nonmodified nanoclay, and polymer modified nanoclay, were selected to blend with the control asphalt to improve the overall performance of the modified asphalt binders and mixtures. The microstructures of original materials and asphalt binders ...

  11. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  12. Length-dependent optical properties of single-walled carbon nanotube samples

    Energy Technology Data Exchange (ETDEWEB)

    Naumov, Anton V. [Department of Chemistry and Richard E. Smalley Institute for Nanoscale Science and Technology, Rice University, 6100 Main Street, Houston, TX 77005 (United States); Ensysce Biosciences, Inc., 7000 Fannin St., Houston, TX 77030 (United States); Tsyboulski, Dmitri A.; Bachilo, Sergei M. [Department of Chemistry and Richard E. Smalley Institute for Nanoscale Science and Technology, Rice University, 6100 Main Street, Houston, TX 77005 (United States); Weisman, R. Bruce, E-mail: weisman@rice.edu [Department of Chemistry and Richard E. Smalley Institute for Nanoscale Science and Technology, Rice University, 6100 Main Street, Houston, TX 77005 (United States)

    2013-08-30

    Highlights: ► Length-independent absorption per atom in single-walled carbon nanotubes. ► Reduced fluorescence quantum yield for short nanotubes. ► Exciton quenching at nanotube ends, sidewall defects probably limits quantum yield. - Abstract: Contradictory findings have been reported on the length dependence of optical absorption cross sections and fluorescence quantum yields in single-walled carbon nanotubes (SWCNTs). To clarify these points, studies have been made on bulk SWCNT dispersions subjected to length fractionation by electrophoretic separation or by ultrasonication-induced scission. Fractions ranged from ca. 120 to 760 nm in mean length. Samples prepared by shear-assisted dispersion were subsequently shortened by ultrasonic processing. After accounting for processing-induced changes in the surfactant absorption background, SWCNT absorption was found constant within ±11% as average nanotube length changed by a factor of 3.8. This indicates that the absorption cross-section per carbon atom is not length dependent. By contrast, in length fractions prepared by both methods, the bulk fluorescence efficiency or average quantum yield increased with SWCNT average length and approached an apparent asymptotic limit near 1 μm. This result is interpreted as reflecting the combined contributions of exciton quenching by sidewall defects and by the ends of shorter nanotubes.

  13. 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.

  14. Potential space applications of nanomaterials and standartization issues

    Science.gov (United States)

    Voronina, Ekaterina; Novikov, Lev

    Nanomaterials surpass traditional materials for space applications in many aspects due to their unique properties associated with nanoscale size of their constituents. This superiority in mechanical, thermal, electrical and optical properties will evidently inspire a wide range of applications in the next generation spacecraft intended for the long-term (~15-20 years) operation in near-Earth orbits and the automatic and manned interplanetary missions as well as in the construction of inhabited bases on the Moon. Nanocomposites with nanoclays, carbon nanotubes and various nanoparticles as fillers are one of the most promising materials for space applications. They may be used as light-weighted and strong structural materials as well as functional and smart materials of general and specific applications, e.g. thermal stabilization, radiation shielding, electrostatic charge mitigation, protection of atomic oxygen influence and space debris impact, etc. Currently, ISO activity on developing standards concerning different issues of nanomaterials manufacturing and applications is high enough. In this presentation, a brief review of existing standards and standards under development in this field is given. Most such standards are related to nanoparticles and nanotube production and characterization, thus the next important step in this activity is the creation of standards on nanomaterial properties and their behavior in different environmental conditions, including extreme environments. The near-Earth’s space is described as an extreme environment for materials due to high vacuum, space radiation, hot and cold plasma, micrometeoroids and space debris, temperature differences, etc. Existing experimental and theoretical data demonstrate that nanomaterials response to various space environment effects may differ substantially from the one of conventional bulk spacecraft materials. Therefore, it is necessary to determine the space environment components, critical for

  15. Petrophysical studies of north American carbonate rock samples and evaluation of pore-volume compressibility models

    Science.gov (United States)

    da Silva, Gilberto Peixoto; Franco, Daniel R.; Stael, Giovanni C.; da Costa de Oliveira Lima, Maira; Sant'Anna Martins, Ricardo; de Moraes França, Olívia; Azeredo, Rodrigo B. V.

    2015-12-01

    In this work, we evaluate two pore volume compressibility models that are currently discussed in the literature (Horne, 1990; Jalalh, 2006b). Five groups of carbonate rock samples from the three following sedimentary basins in North America that are known for their association with hydrocarbon deposits were selected for this study: (i) the Guelph Formation of the Michigan Basin (Middle Silurian); (ii) the Edwards Formation of the Central Texas Platform (Middle Cretaceous); and (iii) the Burlington-Keokuk Formation of the Mississippian System (Lower Mississippian). In addition to the evaluation of the compressibility model, a petrophysical evaluation of these rock samples was conducted. Additional characterizations, such as grain density, the effective porosity, absolute grain permeability, thin section petrography, MICP and NMR, were performed to complement constant pore-pressure compressibility tests. Although both models presented an overall good representation of the compressibility behavior of the studied carbonate rocks, even when considering their broad porosity range (~ 2-38%), the model proposed by Jalalh (2006b) performed better with a confidence level of 95% and a prediction interval of 68%.

  16. 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

  17. Measurement of characteristic prompt gamma rays emitted from oxygen and carbon in tissue-equivalent samples during proton beam irradiation

    OpenAIRE

    Polf, Jerimy C.; Panthi, Rajesh; Mackin, Dennis S; McCleskey, Matt; Saastamoinen, Antti; Roeder, Brian T; Beddar, Sam

    2013-01-01

    The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured ...

  18. Adsorption of DDT and PCB by Nanomaterials from Residual Soil

    OpenAIRE

    Taha, Mohd Raihan; Mobasser, Shariat

    2015-01-01

    This paper presents the findings of a study on adsorption of dichlorodiphenythreechloroethen (DDT) and polychlorinated biphenyls (PCBs) on three nanomaterials including Multi walled Carbon Nanotube (MWNT), nano-clay and nano-alumina. DDT and PCBs are of significant concern due their high toxicity and long environmental half-lives. Experiments were conducted using batch adsorption procedures at different DDT and PCBs concentrations, from 10 to 60 mg/L. The amounts of MWNT, nano-clay and Nano-a...

  19. Raman spectroscopy for nanomaterials characterization

    CERN Document Server

    2012-01-01

    First 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 Raman 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.

  20. Chemical Design of Functional Nanomaterials

    DEFF Research Database (Denmark)

    Egeblad, Kresten

    This thesis deals with a very specific class of functional nanomaterials known as mesoporous zeolites. Zeolites are a class of crystalline aluminosilicate minerals characterized by featuring pores or cavities of molecular dimensions as part of their crystal structure. Mesoporous zeolites are zeol...

  1. Computational design of safer nanomaterials

    NARCIS (Netherlands)

    Burello, E.

    2015-01-01

    Nanomaterials are expected to find applications in numerous consumer products, posing the challenge to guarantee their safety and environmental sustainability before they can be transferred from research labs to end-consumer products. One emerging solution, called safe design, relies on the implemen

  2. Functionalization of nanomaterials with aryldiazonium salts.

    Science.gov (United States)

    Mohamed, Ahmed A; Salmi, Zakaria; Dahoumane, Si Amar; Mekki, Ahmed; Carbonnier, Benjamin; Chehimi, Mohamed M

    2015-11-01

    This paper reviews the surface modification strategies of a wide range of nanomaterials using aryldiazonium salts. After a brief history of diazonium salts since their discovery by Peter Griess in 1858, we will tackle the surface chemistry using these compounds since the first trials in the 1950s. We will then focus on the modern surface chemistry of aryldiazonium salts for the modification of materials, particularly metallic, semiconductors, metal oxide nanoparticles, carbon-based nanostructures, diamond and clays. The successful modification of sp(2) carbon materials and metals by aryldiazonium salts paved the way to innovative strategies for the attachment of aryl layers to metal oxide nanoparticles and nanodiamonds, and intercalation of clays. Interestingly, diazotized surfaces can easily trap nanoparticles and nanotubes while diazotized nanoparticles can be (electro)chemically reduced on electrode/materials surfaces as molecular compounds. Both strategies provided organized 2D surface assembled nanoparticles. In this review, aryldiazonium salts are highlighted as efficient coupling agents for many types of molecular, macromolecular and nanoparticulate species, therefore ensuring stability to colloids on the one hand, and the construction of composite materials and hybrid systems with robust and durable interfaces/interphases, on the other hand. The last section is dedicated to a selection of patents and industrial products based on aryldiazonium-modified nanomaterials. After nearly 160 years of organic chemistry, diazonium salts have entered a new, long and thriving era for the benefit of materials, colloids, and surface scientists. This tempts us to introduce the terminology of "diazonics" we define as the science and technology of aryldiazonium salt-derived materials. PMID:26299313

  3. Constructed Wetlands for Treatment of Organic and Engineered Nanomaterial Contaminants of Emerging Concerns (WaterRF Report 4334)

    Science.gov (United States)

    The goal of this project was to determine hydraulic and carbon loading rates for constructed wetlands required for achieving different levels of organic and nanomaterial contaminants of emerging concern (CECs) removal in constructed wetlands. Specific research objectives included...

  4. Differences on soil organic carbon stock estimation according to sampling type in Mediterranean areas

    Science.gov (United States)

    Parras-Alcántara, Luis; Lozano-García, Beatriz

    2016-04-01

    Soil organic carbon (SOC) is an important part of the global carbon (C) cycle. In addition, SOC is a soil property subject to changes and highly variable in space and time. Consequently, the scientific community is researching the fate of the organic carbon in the ecosystems. In this line, soil organic matter configuration plays an important role in the Soil System (Parras-Alcántara and Lozano García, 2014). Internationally it is known that soil C sequestration is a strategy to mitigate climate change. In this sense, many soil researchers have studied this parameter (SOC). However, many of these studies were carried out arbitrarily using entire soil profiles (ESP) by pedogenetic horizons or soil control sections (SCS) (edaphic controls to different thickness). As a result, the indiscriminate use of both methodologies implies differences with respect to SOC stock (SOCS) quantification. This scenario has been indicated and warned for different researchers (Parras-Alcántara et al., 2015a; Parras-Alcántara et al., 2015b). This research sought to analyze the SOC stock (SOCS) variability using both methods (ESP and SCS) in the Cardeña and Montoro Natural Park (Spain). This nature reserve is a forested area with 385 km2 in southern Spain. Thirty-seven sampling points were selected in the study zone. Each sampling point was analyzed in two different ways, as ESP (by horizons) and as SCS with different depth increments (0-25, 25-50, 50-75 and 75-100 cm). The major goal of this research was to study the SOCS variability at regional scale. The studied soils were classified as Phaeozems, Cambisols, Regosols and Leptosols. The results obtained show an overestimation of SOCS when SCS sampling approach is used compared to ESP. This supports that methodology selection is very important to SOCS quantification. This research is an assessment for modeling SOCS at the regional level in Mediterranean natural areas. References Parras-Alcántara, L., Lozano-García, B., 2014

  5. Transport Properties of Carbonate and Sandstone Samples: Digital Rock Physics and Laboratory Measurements

    Science.gov (United States)

    Alabbad, A. A.; Dvorkin, J. P.

    2015-12-01

    We examined six carbonate samples that included three pairs, each pair cut from the same core, normal and parallel to the bedding. We also examined three sandstone samples comprised of a pair, cur normal and parallel to the bedding, and one sample cut normal to the bedding. For each of these samples, we obtained dual energy digital images with the resolution approximately 0.004 mm, coarser than the pore-scale resolution. As a result, we did not resolve the pore structure. Still, these images provided us with the bulk density (ρb) and photoelectric factor (Pf) at each voxel in 3D. The Pf volumes were used to estimate the mineralogy at each voxel by partitioning the carbonate mineralogy between calcite and dolomite and partitioning the sandstone mineralogy between pure quartz and "dirty sandstone" (Plumb et al., 1991) for one scenario and between pure quartz and illite for the other scenario. From this mineralogy we obtained the grain (matrix) density (ρs) at each voxel. Next, by using ρb and ρs and assuming that the pores were filled with air, we computed the total porosity (ϕt) at each voxel from mass balance. Porosity thus obtained was used to estimate the electrical formation factor (F) at each voxel by assuming that F relates to ft according to Archie's equation (Archie, 1942). We also computed the absolute permeability (k) at each voxel by assuming that k relates to ϕt according to the Kozeny-Carman equation (Carman, 1956). Next, by employing a Darcy simulator, these 3D resistivity and permeability volumes were used to compute the effective permeability and electrical formation factor of the whole samples along the three axial directions to assess the anisotropy of these transport properties. These computational results were compared to laboratory measurements. The computed effective bulk density, grain density, and porosity appeared to closely match the laboratory values. So did the formation factor. By selecting an appropriate grain size, we also

  6. Novel Techniques for Optical Characterization of Single-Walled Carbon Nanotube Samples

    Science.gov (United States)

    Streit, Jason K.

    Photoluminescence spectroscopy has emerged as a powerful tool for characterizing the structure and optical properties of single-walled carbon nanotube (SWCNT) samples. This thesis will discuss the development and application of new fluorescence-based methods designed to fully characterize bulk SWCNT suspensions by length and structural composition. An efficient new method is demonstrated to measure length distributions of aqueous SWCNT samples by analyzing the diffusional motions of many individual nanotubes captured in sequences of short-wave infrared (SWIR) fluorescence images. This method, termed length analysis by nanotube diffusion (LAND), provides distributions in very good agreement with those obtained by conventional atomic force microscopy analysis. A novel microscopy technique is described to measure the peak emission wavelengths of many individual nanotubes without the use of a spectrometer. We exploit the chromatic aberration of an objective lens to deduce emission wavelength from focal depth. Spectral measurements successfully reproduce bulk emission spectra and also provide relative abundances of specific SWCNT structures. A new approach is applied to find nanotube concentrations by directly counting SWCNTs in SWIR fluorescence images. Concentrations are used to rigorously determine absolute absorption cross sections for the E11 and E22 electronic transitions of the (6,5), (7,5), (7,6), (8,6), (8,7) and (9,7) SWCNT species. It is found that the absorption cross section per carbon atom decreases with increasing nanotube diameter. Finally, the spectral analysis of fluorescence fluctuations (SAFF) method is developed and used to characterize SWCNT samples by structural composition, sample quality, and aggregation state. Fluorescence spectra are sequentially measured from small volumes of slowly flowing dilute samples and the intensity fluctuations resulting from small statistical variations in nanotube concentration are analyzed. The ratio of the squared

  7. Integrated geochemical and geophysical monitoring of CO2-rich fluids in carbonate samples.

    Science.gov (United States)

    Vialle, S.; Contraires, S.; Zinzsner, B.; Clavaud, J. B.; Mahiouz, K.; Zuddas, P.; Zamora, M. C.

    2014-12-01

    Percolation of CO2-rich fluids in limestones causes the dissolution (and eventual reprecipitation) of calcium carbonate minerals, which affects the rock microstructure and changes the rock petrophysical properties (i.e. hydraulic, electrical and elastic properties). In addition, microstructural changes further feedback to affect flow paths as well as the location and magnitude of fluid-rock interactions. To better understand this complex coupled problem and to assess the possibility of geophysical monitoring in chemically reactive geosystems, we performed percolation laboratory experiments on two well-characterized carbonate samples (99% calcite), from Estaillades and St Maximin (France), 10 cm in diameter and 35 and 16 cm in length, respectively. We monitored aqueous chemistry parameters (pH, calcium concentration and total alkalinity) and petrophysical properties (permeability, electrical formation factor and acoustic velocities). X-ray tomography imaging of the rock samples were also performed before and after the flow experiments. The measured chemical and electrical parameters allowed rapid detection of the dissolution of calcite in the downstream fluid. After circulating fluids of various salinities at 5mL·min-1 for 32 days (about 290 pore sample volumes) at a pCO2 of 1 atm (pH = 4) in the Estaillades sample, porosity increased by 7%, permeability increased by one order of magnitude, electrical formation factor decreased by 15% and P- and S-wave velocities, measured every cm along the sample main axis, decreased non-uniformly by less than 1% to up to 14%. X-ray microtomography revealed the creation of a ramified wormhole; these, along with the convex curvature of the permeability-porosity relationship, are consistent with a transport-controlled dissolution regime for which advection processes are greater than diffusion processes. Similar results were obtained for the St Maximin sample, except that the wormhole is more compact, which is most likely due to a

  8. Multiwavelength Raman spectroscopy analysis of a large sampling of disordered carbons extracted from the Tore Supra tokamak

    CERN Document Server

    Pardanaud, Cedric; Roubin, P

    2014-01-01

    Disordered carbon often exhibit a complex Raman spectrum, with four to six components. Here, a large variety of disordered carbons, forming a collection of samples with a great variety of structures, are analysed using multi-wavelength Raman microscopy (325.0, 514.5, 785.0 nm). They allow us to extend Raman behaviour known for nano-crystalline graphite to amorphous carbons, (dependence with the excitation wavelength) and other known for amorphous carbons to nano-crystalline graphite, (differentiation of the smallest cluster size probed using different excitation wavelengths). Experimental spectra were compared to simulated spectra, built using known laws, to evidence a new source of broadening.

  9. Engineering Nanomaterial Surfaces for Biomedical Applications

    Science.gov (United States)

    Wang, Xin; Liu, Li-Hong; Ramström, Olof; Yan, Mingdi

    2014-01-01

    Nanomaterials, possessing unique physical and chemical properties, have attracted much interest and generated wide varieties of applications. Recent investigations of functionalized nanomaterials have expanded into the biological area, providing a versatile platform in biomedical applications such as biomolecular sensing, biological imaging, drug delivery and disease therapy. Bio-functions and bio-compatibility of nanomaterials are realized by introducing synthetic ligands or natural biomolecules onto nanomaterials, and combining ligand-receptor biological interactions with intrinsic nanomaterial properties. Common strategies of engineering nanomaterial surfaces involve physisorption or chemisorption of desired ligands. We developed a photochemically initiated surface coupling chemistry, bringing versatility and simplicity to nanomaterial functionalization. The method was applied to attach underivatized carbohydrates efficiently on gold and iron oxide nanoparticles, and the resulting glyconanoparticles were successfully used as a sensitive biosensing system probing specific interactions between carbohydrates and proteins as well as bacteria. PMID:19596820

  10. Synoptic Sampling of Dissolved Nitrogen Species and Organic Carbon in the Rio Grande Basin

    Science.gov (United States)

    Villinski, J. E.; Hogan, J. F.; Brooks, P. D.; Haas, P. A.; Mills, S. K.

    2002-12-01

    Synoptic sampling has been performed along the Rio Grande from the headwaters in Colorado to Fort Quitman, Texas, south of El Paso. Samples from August 2001 and January 2002 were analyzed for nitrate (NO3-), ammonium (NH_{4}$+), total dissolved nitrogen (TDN), and dissolved organic carbon (DOC). DOC concentrations increase slowly between Colorado and southern New Mexico and then approximately double in Texas. Large sources of N during both sampling periods were the urban areas around Albuquerque and El Paso, Texas and Ciudad Juarez, Mexico, and agricultural regions in the Rincon and Mesilla valleys of southern New Mexico. Nitrate-N concentrations remained high south of Albuquerque to Elephant Butte reservoir in the summer, presumably due to lack of primary production. Inorganic N concentrations generally are higher in the winter than in the summer. During the summer, ammonium concentrations were greater than 100 mg N/l only at the outlet of Elephant Butte Reservoir, and in Texas. However, winter concentrations were on average an order of magnitude greater, again with the largest ammonium values (5000 \\mug N/l) in Texas. These patterns are consistent with a reduction in biological nutrient demand during the non-growing season.

  11. Microporous Carbon Spheres Solid Phase Membrane Tip Extraction for the Analysis of Nitrosamines in Water Samples

    International Nuclear Information System (INIS)

    A simple solid phase membrane tip extraction (SPMTE) utilizing microporous carbon spheres (MCS) was developed for the analysis of nitrosamines in aqueous samples. The method termed MCS-SPMTE was optimized for various important extraction parameters namely conditioning organic solvent, extraction time, effects of salt addition and pH change, desorption time, desorption solvent and sample volume. Under the optimized conditions, the method indicated good linearity in the range of 10-100 μg/ L with coefficients of determination, r2≥0.9984. The method also demonstrated good reproducibility with % RSDs values ranging from 2.2 - 8.9 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) for the method ranged from 3.2 - 4.8 μg/ L and 10.9 - 15.9 μg/L respectively. Recoveries for both tap-water and lake water samples spiked at 10 μg/L were in the range of 83.2 - 107.5 %. (author)

  12. Carbon Nanostructures Containing Polyhedral Oligomeric Silsesquioxanes (POSS)

    NARCIS (Netherlands)

    Potsi, Georgia; Rossos, Andreas; Kouloumpis, Antonios; Antoniou, Myrsini K.; Spyrou, Konstantinos; Karakassides, Michael A.; Gournis, Dimitrios; Rudolf, Petra

    2015-01-01

    This mini review describes the synthesis and properties of carbon nanostructures containing organic-inorganic cage-like polyhedral oligomeric silsesquioxane (POSS). The physical and chemical functionalization of carbon nanomaterials such as graphene, graphene oxide, carbon nanotubes, and fullerenes

  13. EVALUATION OF ARG-1 SAMPLES PREPARED BY CESIUM CARBONATE DISSOLUTION DURING THE ISOLOK SME ACCEPTABILITY TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T.; Hera, K.; Coleman, C.

    2011-12-05

    Evaluation of Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) recently completed the evaluation of one of these opportunities - the possibility of using an Isolok sampling valve as an alternative to the Hydragard valve for taking DWPF process samples at the Slurry Mix Evaporator (SME). The use of an Isolok for SME sampling has the potential to improve operability, reduce maintenance time, and decrease CPC cycle time. The SME acceptability testing for the Isolok was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 and was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNLRP-2011-00145. RW-0333P QA requirements applied to the task, and the results from the investigation were documented in SRNL-STI-2011-00693. Measurement of the chemical composition of study samples was a critical component of the SME acceptability testing of the Isolok. A sampling and analytical plan supported the investigation with the analytical plan directing that the study samples be prepared by a cesium carbonate (Cs{sub 2}CO{sub 3}) fusion dissolution method and analyzed by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The use of the cesium carbonate preparation method for the Isolok testing provided an opportunity for an additional assessment of this dissolution method, which is being investigated as a potential replacement for the two methods (i.e., sodium peroxide fusion and mixed acid dissolution) that have been used at the DWPF for the analysis of SME samples. Earlier testing of the Cs{sub 2}CO{sub 3} method yielded promising results which led to a TTR from Savannah River Remediation, LLC (SRR) to SRNL for additional support and an associated TTQAP to direct the SRNL efforts. A technical report resulting

  14. Automated determination of the stable carbon isotopic composition (δ13C) of total dissolved inorganic carbon (DIC) and total nonpurgeable dissolved organic carbon (DOC) in aqueous samples: RSIL lab codes 1851 and 1852

    Science.gov (United States)

    Révész, Kinga M.; Doctor, Daniel H.

    2014-01-01

    The purposes of the Reston Stable Isotope Laboratory (RSIL) lab codes 1851 and 1852 are to determine the total carbon mass and the ratio of the stable isotopes of carbon (δ13C) for total dissolved inorganic carbon (DIC, lab code 1851) and total nonpurgeable dissolved organic carbon (DOC, lab code 1852) in aqueous samples. The analysis procedure is automated according to a method that utilizes a total carbon analyzer as a peripheral sample preparation device for analysis of carbon dioxide (CO2) gas by a continuous-flow isotope ratio mass spectrometer (CF-IRMS). The carbon analyzer produces CO2 and determines the carbon mass in parts per million (ppm) of DIC and DOC in each sample separately, and the CF-IRMS determines the carbon isotope ratio of the produced CO2. This configuration provides a fully automated analysis of total carbon mass and δ13C with no operator intervention, additional sample preparation, or other manual analysis. To determine the DIC, the carbon analyzer transfers a specified sample volume to a heated (70 °C) reaction vessel with a preprogrammed volume of 10% phosphoric acid (H3PO4), which allows the carbonate and bicarbonate species in the sample to dissociate to CO2. The CO2 from the reacted sample is subsequently purged with a flow of helium gas that sweeps the CO2 through an infrared CO2 detector and quantifies the CO2. The CO2 is then carried through a high-temperature (650 °C) scrubber reactor, a series of water traps, and ultimately to the inlet of the mass spectrometer. For the analysis of total dissolved organic carbon, the carbon analyzer performs a second step on the sample in the heated reaction vessel during which a preprogrammed volume of sodium persulfate (Na2S2O8) is added, and the hydroxyl radicals oxidize the organics to CO2. Samples containing 2 ppm to 30,000 ppm of carbon are analyzed. The precision of the carbon isotope analysis is within 0.3 per mill for DIC, and within 0.5 per mill for DOC.

  15. Compressive sampling based interior reconstruction for dynamic carbon nanotube micro-CT.

    Science.gov (United States)

    Yu, Hengyong; Cao, Guohua; Burk, Laurel; Lee, Yueh; Lu, Jianping; Santago, Pete; Zhou, Otto; Wang, Ge

    2009-01-01

    In the computed tomography (CT) field, one recent invention is the so-called carbon nanotube (CNT) based field emission x-ray technology. On the other hand, compressive sampling (CS) based interior tomography is a new innovation. Combining the strengths of these two novel subjects, we apply the interior tomography technique to local mouse cardiac imaging using respiration and cardiac gating with a CNT based micro-CT scanner. The major features of our method are: (1) it does not need exact prior knowledge inside an ROI; and (2) two orthogonal scout projections are employed to regularize the reconstruction. Both numerical simulations and in vivo mouse studies are performed to demonstrate the feasibility of our methodology. PMID:19923686

  16. Extensive Sampling of Forest Carbon using High Density Power Line Lidar

    Science.gov (United States)

    Hampton, H. M.; Chen, Q.; Dye, D. G.; Hungate, B. A.

    2013-12-01

    Estimating carbon sequestration and greenhouse gas emissions from forest management, natural processes, and disturbance is of growing interest for mitigating global warming. Ponderosa pine is common at mid-elevations throughout the western United States and is a dominant tree species in southwestern forests. Existing unmanaged "relict" sites and stand reconstructions of southwestern ponderosa pine forests from before European settlement (late 1800s) provide evidence of forests of larger trees of lower density and less vulnerability to severe fires than today's typical conditions of high densities of small trees that have resulted from a century of fire suppression. Forest treatments to improve forest health in the region include tree cutting focused on small-diameter trees (thinning), low-intensity prescribed burning, and monitoring rather than suppressing wildfires. Stimulated by several uncharacteristically-intense fires in the last decade, a collaborative process found strong stakeholder agreement to accelerate forest treatments to reduce fire risk and restore ecological conditions. Land use planning to ramp up management is underway and could benefit from quick and inexpensive techniques to inventory tree-level carbon because existing inventory data are not adequate to capture the range of forest structural conditions. Our approach overcomes these shortcomings by employing recent breakthroughs in estimating aboveground biomass from high resolution light detection and ranging (lidar) remote sensing. Lidar is an active remote sensing technique, analogous to radar, which measures the time required for a transmitted pulse of laser light to return to the sensor after reflection from a target. Lidar data can capture 3-dimensional forest structure with greater detail and broader spatial coverage than is feasible with conventional field measurements. We developed a novel methodology for extensive sampling and field validation of forest carbon, applicable to managed and

  17. 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. PMID:25088794

  18. 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.

  19. Nanomaterial-Assisted Signal Enhancement of Hybridization for DNA Biosensors: A Review

    Directory of Open Access Journals (Sweden)

    Minqiang Li

    2009-09-01

    Full Text Available Detection of DNA sequences has received broad attention due to its potential applications in a variety of fields. As sensitivity of DNA biosensors is determined by signal variation of hybridization events, the signal enhancement is of great significance for improving the sensitivity in DNA detection, which still remains a great challenge. Nanomaterials, which possess some unique chemical and physical properties caused by nanoscale effects, provide a new opportunity for developing novel nanomaterial-based signal-enhancers for DNA biosensors. In this review, recent progress concerning this field, including some newly-developed signal enhancement approaches using quantum-dots, carbon nanotubes and their composites reported by our group and other researchers are comprehensively summarized. Reports on signal enhancement of DNA biosensors by non-nanomaterials, such as enzymes and polymer reagents, are also reviewed for comparison. Furthermore, the prospects for developing DNA biosensors using nanomaterials as signal-enhancers in future are also indicated.

  20. Final Report: "Energetics of Nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Navrotsky, Alexandra [Univ. of California, Davis, CA (United States); Ross, Nancy [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Woodfield, Brian [Brigham Young Univ., Provo, UT (United States)

    2015-02-14

    Nanomaterials, solids with very small particle size, form the basis of new technologies that are revolutionizing fields such as energy, lighting, electronics, medical diagnostics, and drug delivery. These nanoparticles are different from conventional bulk materials in many ways we do not yet fully understand. This project focused on their structure and thermodynamics and emphasized the role of water in nanoparticle surfaces. Using a unique and synergistic combination of high-tech techniques—namely oxide melt solution calorimetry, cryogenic heat capacity measurements, and inelastic neutron scattering—this work has identified differences in structure, thermodynamic stability, and water behavior on nanoparticles as a function of composition and particle size. The systematics obtained increase the fundamental understanding needed to synthesize, retain, and apply these technologically important nanomaterials and to predict and tailor new materials for enhanced functionality, eventually leading to a more sustainable way of life.

  1. Introduction to nanoscience and nanomaterials

    CERN Document Server

    Agrawal, Dinesh C

    2013-01-01

    This textbook is aimed primarily at the senior undergraduate and first year graduate students from the various engineering and sciences departments including physics, chemistry, materials engineering, chemical engineering, electrical engineering, mechanical engineering, bioengineering, and biology. Researchers in the areas of nanomaterials and nanoscience will also find the book useful for building the background necessary to understand the current literature and as a reference book. The text assumes only a basic level of competency in physics, chemistry and mathematics. Some of the background material and introductory matter are included in the first few chapters and as appendices. Although this material may be familiar to some of the students, it is the author's experience after teaching such a course for many years that this can not be taken for granted and moreover, serves as a ready reference to understand the text. As the area of nanoscience, nanotechnology and nanomaterials is a fast developing one, a...

  2. Nanomaterials – the driving force

    Directory of Open Access Journals (Sweden)

    Michael J. Pitkethly

    2004-12-01

    Full Text Available The growth in activity surrounding nanomaterials continues unabated as more R&D funds are poured into nanotechnology and companies look to exploit the expanding range of novel properties that are being discovered. Advances in existing production techniques are improving the quality and yields, providing a clear prospect of commercially viable volume production. There is still a wide range of processes being used, and it is clear those that will be commercially successful will be those for which the materials have been developed at the same time as the application. Recent reports from a number of working groups have highlighted the need for increased examination of the health, environmental, and ethical aspects of nanotechnology, and this is an area that the industry will need to understand more fully and take appropriate action on if the benefits of nanomaterials are to be realized.

  3. FINAL REPORT: "Energetics of Nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Navrotsky, Alexandra [Univ. of California, Davis, CA (United States); Ross, Nancy [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Woodfield, Brian [Brigham Young Univ., Provo, UT (United States)

    2016-08-31

    Nanomaterials, solids with very small particle size, form the basis of new technologies that are revolutionizing fields such as energy, lighting, electronics, medical diagnostics, and drug delivery. These nanoparticles are different from conventional bulk materials in many ways we do not yet fully understand. This project focused on their structure and thermodynamics and emphasized the role of water in nanoparticle surfaces. Using a unique and synergistic combination of high-tech techniques—namely oxide melt solution calorimetry, cryogenic heat capacity measurements, and inelastic neutron scattering—this work has identified differences in structure, thermodynamic stability, and water behavior on nanoparticles as a function of composition and particle size. The systematics obtained increase the fundamental understanding needed to synthesize, retain, and apply these technologically important nanomaterials and to predict and tailor new materials for enhanced functionality, eventually leading to a more sustainable way of life.

  4. Editorial: Nanomaterials at the Biointerface

    Directory of Open Access Journals (Sweden)

    Zhi Ping (Gordon Xu

    2014-06-01

    Full Text Available Bioapplication of nanomaterials involves several key processes that occurat the biointerface, such as internalization of nanoparticles by various cells, attachment of nanomaterials onto the bacteria to form granulates, and penetration of nutrient elements on the leaf surface from the nutrient reservoir – nanocrystals. This special issue therefore presents the most recent research development of nanomaterials at the biointerface, as summarized by a multidisciplinary team of international experts in these broad fields. Biomedical applications of various nanomaterials are intensively investigated in the recent decades. For example, many efforts have been made to develop functional mesoporous silica nanoparticles (MSNs to enhance the biocompatibility, drug loading efficacy, drug delivery efficiency, drug control releaseproperties and cancer treatment effectiveness. In this issue, Zhang et al. (Tianjin University, China [1]briefly review the recent progresses in this particular area. Another example is utilization of nanoparticles as biomarkers. So this special issue also includes a mini-review paper by Centeno and Xie (University Technology Malaysia [2] thatconcisely presents the principle and simulation results of dye molecules’ fluorescence enhancement by the nearby nanostructured metals through their coupling effect. Nanomaterials can alsobe used as effective antimicrobial agents. For example, Liu et al. (Curtin University of Technology, Australia [3] briefly review the recent progress of silver nanoparticles (AgNPs, andin particular, their efforts to modify AgNPs by conjugating antimicrobial cell penetration peptide to selectively bind to microorganism and improve the therapeutic index. More interestingly, nanomaterialsare increasingly investigated as effective foliar fertilizers to provide micronutrient elements for a longer term. This particularly takes the advantage of nanocrystals’sheet-like morphology as sheet-like crystals have the

  5. Pathophysiologic mechanisms of biomedical nanomaterials.

    Science.gov (United States)

    Wang, Liming; Chen, Chunying

    2016-05-15

    Nanomaterials (NMs) have been widespread used in biomedical fields, daily consuming, and even food industry. It is crucial to understand the safety and biomedical efficacy of NMs. In this review, we summarized the recent progress about the physiological and pathological effects of NMs from several levels: protein-nano interface, NM-subcellular structures, and cell-cell interaction. We focused on the detailed information of nano-bio interaction, especially about protein adsorption, intracellular trafficking, biological barriers, and signaling pathways as well as the associated mechanism mediated by nanomaterials. We also introduced related analytical methods that are meaningful and helpful for biomedical effect studies in the future. We believe that knowledge about pathophysiologic effects of NMs is not only significant for rational design of medical NMs but also helps predict their safety and further improve their applications in the future.

  6. Functional organic nanomaterials

    Science.gov (United States)

    Kohlmeyer, Ryan R.

    pi-Conjugated polymers have a wide range of applications such as photovoltaics, light-emitting diodes, and sensors. To gain a better understanding of these systems, monodisperse oligomers can be used as a more simplistic model to generate predictive structural and physical properties of corresponding polymers. A divergent/convergent synthetic approach to synthesis of monodisperse pi-conjugated oligomers has been developed. These well-defined, thiophene-containing molecular building blocks have been successfully coupled to a ferrocene hinge, which has been found to be highly efficient in the transport of gold atoms using a gold scanning tunneling microscopy tip. Carbon nanotubes (CNTs) represent a rare class of materials, which exhibit a number of outstanding properties in a single material system, such as high aspect ratio, small diameter, light weight, high mechanical strength, high electrical and thermal conductivities, and near-IR optical and optoelectronic properties. Aerogels are highly porous, low-density materials comprised of a solid, three-dimensional (3D) nanoscale network fully accessible to ions and molecules. By combining the extraordinary properties of CNTs with those of aerogels, a new class of materials becomes accessible with unique multifunctional material properties. CNT aerogels that are mechanically stable and stiff, highly porous, and exhibit excellent electrical conductivity and large specific surface area have been developed. CNTs are recognized as the ultimate carbon fibers for high-performance, multifunctional materials, where an addition of only a small amount of CNTs, if engineered appropriately, could lead to simultaneously enhanced mechanical strength and electrical conductivity. For the first time, using core-shell multi-walled CNTs as a filler to increase the dielectric constant and reduce the dielectric loss of nanotube-polymer composites has been demonstrated. While most efforts in the field of CNT-polymer composites have been

  7. New nanomaterials for photonic application

    Science.gov (United States)

    Minh, Le Quoc; Anh, Tran Kim; Binh, Nguyen Thanh; Mien, Vu Doan

    2012-06-01

    A brief survey of the development of new nanomaterials for photonic application will be presented. Based on the photoresponsive sol gel nanohybrid of polymethamethyl acrylate, silica, and zirconia (ASZ) or titania (AST) have been fabricated some planar light guiding structures and devices. The lanthanide containing nanosphere with core/shell structures have been synthesized in using a modified solgel process. The opal like photonic crystal structures have been fabricated by self assembling technique.

  8. Nanomaterial-enabled neural stimulation

    Directory of Open Access Journals (Sweden)

    Yongchen eWang

    2016-03-01

    Full Text Available Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed.

  9. Nanomaterial-Enabled Neural Stimulation.

    Science.gov (United States)

    Wang, Yongchen; Guo, Liang

    2016-01-01

    Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed.

  10. Nanomaterial-Enabled Neural Stimulation.

    Science.gov (United States)

    Wang, Yongchen; Guo, Liang

    2016-01-01

    Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed. PMID:27013938

  11. REACH and nanomaterials: current status

    International Nuclear Information System (INIS)

    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.

  12. Sustainable nanomaterials? – How to apply “early warning signs” to screen nanomaterials for harmful properties

    DEFF Research Database (Denmark)

    Baun, Anders; Hansen, Steffen Foss

    2014-01-01

    ) and nanoscale zero‐valent iron), it was found that only nanoTiO2 fulfils all the five criteria. Depending on the length of the nanotubes, carbon nanotubes fulfil 3 or 4 criteria whereas liposomes, poly(lactic‐co‐glycolic acid), nanoscale zero‐valent iron fulfil only one criteria. We will discuss how...... such as novelty, persistency, whether materials are readily dispersed in the environment, and whether they bioaccumulate or lead to potentially irreversible action. Through an analysis of these criteria using five well‐known nanomaterials (titanium dioxide, carbon nanotubes, liposomes, poly(lacticcoglycolic acid...

  13. Toxicity of nanomaterials; an undermined issue.

    Science.gov (United States)

    Mogharabi, Mehdi; Abdollahi, Mohammad; Faramarzi, Mohammad Ali

    2014-01-01

    Nanomaterials are employed in extensive variety of commercial products such as electronic components, cosmetics, food, sports equipment, biomedical applications, and medicine. With the increasing utilization of engineered nanomaterials, the potential exposure of human to nanoparticles is rapidly increasing. Nowadays when new nanomaterials with new applications are introduced, mostly good and positive effects are mentioned whereas possible hazards arising from nanosize of the compounds are undermined. Toxicology studies of nanomaterials demonstrate some adverse effects in some human organs such as central nerve system, immune system, and lung. There is lack of complete information about human toxicity and environmental waste of nanomaterials. We aimed to highlight current toxicological concerns of potentially useful nanomaterials which are now used in pharmaceutical and biomedical sciences. PMID:25123555

  14. Stabilization of Soft Soil Using Nanomaterials

    Directory of Open Access Journals (Sweden)

    Zaid Hameed Majeed

    2014-07-01

    Full Text Available Tests were conducted to investigate the influence of using nanomaterials in the modification and stabilization of soft soil. The soft soils were collected from two sites and treated with three nanomaterial types (nano-copper, nano-clay and nano-magnesium. Nanomaterials were added in small amount (≤1.0% by dry weight of the soil. Laboratory tests to determine the Atterberg limits, linear shrinkage, compaction characteristics and unconfined compressive strength were performed. Results of the investigation showed significant improvement in maximum dry density, plasticity index, linear shrinkage and unconfined compressive strength. The improvement is dependent on the type of nanomaterials. The unconfined compressive strength and maximum dry density increased as the nanomaterials content increased until reach a percentage after which the strength will be decrease. Thus, the addition of finer particles such as nanomaterials, even at low doses, could enhance the properties of soil.

  15. 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...

  16. Carbon mineralisation and plant growth in soil amended with compost samples at different degrees of maturity.

    Science.gov (United States)

    García-Gómez, Antonio; Bernal, María Pilar; Roig, Asunción

    2003-04-01

    The carbon and nitrogen mineralisation of a composting mixture of brewing yeast and lemon tree prunings was studied, at different degrees of stabilisation of this matrix, within an incubation experiment in soil. Meanwhile, a growth test in pots with ryegrass (Lolium perenne L.) was carried out using the selected soil and equal amounts of the composting mixture taken at different maturation steps, in order to evaluate the additions of these organic amendments in terms of fertilising value. Samples of the composting mixture, when poorly transformed through the biostabilisation process, showed high CO2-C releases in the soil, due to the microbial attack on easily degradable organic fractions still present in the mixture, with 24.7% mineralisation of the initial total organic carbon (TOC) after a 70 day incubation. On the other hand, mature compost was the most stable matrix, with only 5.4% of TOC mineralised after 70 days. Furthermore, amendments with the initial composting mixture led to negative net N-mineralisation during 56 days of incubation with soil. Only slight negative values of the net N-mineralisation were detected with fully stabilised compost. Nevertheless, pot experiments with ryegrass revealed that mature compost may promote N mineralisation to certain extents. Moreover, mature compost did not produce any phytotoxic effect, behaving as a slow-action organic fertiliser with N made available through a progressive mineralisation. Thus, the results gained through this study are a confirmation that the fertilising quality of a compost destined for agricultural uses is heavily affected by the complete exhaustion of the maturation reactions.

  17. Influence of aggregate shapes on drying and carbonation phenomena in 3D concrete numerical samples

    International Nuclear Information System (INIS)

    This study aims at generating numerical 3D samples of concrete so as to study the effects of the granular inclusions shape on the macroscopic kinetics of reactive transport phenomena. Two types of meso-structure configurations are considered: the first one is composed of a matrix of mortar in which are randomly distributed inclusions corresponding to the concrete coarse aggregates, and the second one also includes a steel rebar. The choice of a mesoscopic modeling for the mortar matrix is based on the need to obtain numerical structures of reasonable size. In particular, the Interfacial Transition Zones (ITZs) are assumed to be incorporated into the homogenized mortar properties. This study is applied to the case of drying and atmospheric carbonation by using simplified models solved by the finite element code Cast3M. The purpose is to quantify the influence of the aggregate shape on the kinetics of macroscopic transfer and the iso-value lines for some physical variables representative of the reactive transport problems: saturation degree for drying, and porosity, calcite and portlandite concentrations for carbonation. Basic aggregates shapes are studied (spheres, cubes), as well as more complex ones (Voronoi particles) which are supposed to be more representative of real aggregates. The effects of 'non-isotropic' shapes (oblate and prolate ones) are also investigated. It is shown that the influence of the aggregate shapes appears negligibly small on macroscopic indicators, except for oblate shapes with aspect ratios of 3. This latter case also exhibits substantial local delayed effects and a more important variability, which may have some importance for a precise description and estimation of degradation processes related to steel rebar corrosion. (authors)

  18. FORMING AND PRECISION MACHINING TO NANOMATERIALS LUMP

    Institute of Scientific and Technical Information of China (English)

    Zhan Jie; Zhang Jin; Chen Bingkui; Chen Xiaoan

    2004-01-01

    The technology of forming and machining lump nano-materials has been investigated. Grinding, abrasive machining test has been conducted to Fe, Co, Ni and Al lump nano-materials. Experiments have been done to measure grinding force, grinding thermal, machining roughness and micro-hardness. Image analysis is carried out by metallographic and scanning tunnel microscopic microscope. Researches provide the basis data for forming and machining lump nano-materials.

  19. Toxicity of nanomaterials; an undermined issue

    OpenAIRE

    Mogharabi, Mehdi; Abdollahi, Mohammad; Faramarzi, Mohammad Ali

    2014-01-01

    Nanomaterials are employed in extensive variety of commercial products such as electronic components, cosmetics, food, sports equipment, biomedical applications, and medicine. With the increasing utilization of engineered nanomaterials, the potential exposure of human to nanoparticles is rapidly increasing. Nowadays when new nanomaterials with new applications are introduced, mostly good and positive effects are mentioned whereas possible hazards arising from nanosize of the compounds are und...

  20. Measurement of Carbon Fixation Rates in Leaf Samples — Use of carbon-14 labeled sodium bicarbonate to estimate photosynthetic rates

    OpenAIRE

    sprotocols

    2014-01-01

    Author: David R. Caprette ### Generation of a Light Curve To address the hypothesis concerning photosynthetic efficiency it is necessary to expose sun and shade leaves to a range of light intensities long enough for them to fix significant amounts of carbon. It is necessary to expose identical surface areas under favorable conditions which are identical for all leaves except for light intensity (the experimental variable). A means of measuring the rate of carbon fixation is also neces...

  1. In situ investigation of the mechanical properties of nanomaterials by transmission electron microscopy

    Institute of Scientific and Technical Information of China (English)

    Jun Sun; Feng Xu; Li-Tao Sun

    2012-01-01

    With the progress of modern transmission electron microscopy (TEM) and development of dedicated functional TEM specimen holders,people can now manipulate a nano-object with nanometer-range precision and simultaneously acquire mechanical data together with atomic-scale structural information.This advanced methodology is playing an increasingly important role in nanomechanics.The present review summarizes relevant studies on the in situ investigation of mechanical properties of various nanomaterials over the past decades.These works enrich our knowledge not only on nanomaterials (such as carbon nanotubes,carbon onions,boron nitride nanotubes,silicon nanowires and graphene,etc.) but also on mechanics at the nanoscale.

  2. Nano-material and method of fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Menchhofer, Paul A; Seals, Roland D; Howe, Jane Y; Wang, Wei

    2015-02-03

    A fluffy nano-material and method of manufacture are described. At 2000.times. magnification the fluffy nanomaterial has the appearance of raw, uncarded wool, with individual fiber lengths ranging from approximately four microns to twenty microns. Powder-based nanocatalysts are dispersed in the fluffy nanomaterial. The production of fluffy nanomaterial typically involves flowing about 125 cc/min of organic vapor at a pressure of about 400 torr over powder-based nano-catalysts for a period of time that may range from approximately thirty minutes to twenty-four hours.

  3. Quantifying the sampling error in tree census measurements by volunteers and its effect on carbon stock estimates.

    Science.gov (United States)

    Butt, Nathalie; Slade, Eleanor; Thompson, Jill; Malhi, Yadvinder; Riutta, Terhi

    2013-06-01

    A typical way to quantify aboveground carbon in forests is to measure tree diameters and use species-specific allometric equations to estimate biomass and carbon stocks. Using "citizen scientists" to collect data that are usually time-consuming and labor-intensive can play a valuable role in ecological research. However, data validation, such as establishing the sampling error in volunteer measurements, is a crucial, but little studied, part of utilizing citizen science data. The aims of this study were to (1) evaluate the quality of tree diameter and height measurements carried out by volunteers compared to expert scientists and (2) estimate how sensitive carbon stock estimates are to these measurement sampling errors. Using all diameter data measured with a diameter tape, the volunteer mean sampling error (difference between repeated measurements of the same stem) was 9.9 mm, and the expert sampling error was 1.8 mm. Excluding those sampling errors > 1 cm, the mean sampling errors were 2.3 mm (volunteers) and 1.4 mm (experts) (this excluded 14% [volunteer] and 3% [expert] of the data). The sampling error in diameter measurements had a small effect on the biomass estimates of the plots: a volunteer (expert) diameter sampling error of 2.3 mm (1.4 mm) translated into 1.7% (0.9%) change in the biomass estimates calculated from species-specific allometric equations based upon diameter. Height sampling error had a dependent relationship with tree height. Including height measurements in biomass calculations compounded the sampling error markedly; the impact of volunteer sampling error on biomass estimates was +/- 15%, and the expert range was +/- 9%. Using dendrometer bands, used to measure growth rates, we calculated that the volunteer (vs. expert) sampling error was 0.6 mm (vs. 0.3 mm), which is equivalent to a difference in carbon storage of +/- 0.011 kg C/yr (vs. +/- 0.002 kg C/yr) per stem. Using a citizen science model for monitoring carbon stocks not only has

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

    OpenAIRE

    Luminosu I.; Popov D.; Zaharie I.

    2008-01-01

    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...

  5. A simple approach for fabricating solid-contact ion-selective electrodes using nanomaterials as transducers

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Rongning; Yin, Tanji; Qin, Wei, E-mail: wqin@yic.ac.cn

    2015-01-01

    Highlights: • A general method for fabricating nanomaterials based solid-contact ISEs is developed. • The mixture of an ionic liquid and a nanomaterial is used as intermediate layer. • The detection limits of the proposed sensors are in the nanomolar range. • The developed electrodes exhibit a good response time and excellent stability. - Abstract: A simple and robust approach for the development of solid-state ion-selective electrodes (ISEs) using nanomaterials as solid contacts is described. The electrodes are fabricated by using the mixture of an ionic liquid (IL) and a nanomaterial as intermediate layer, formed by melting the IL. Tetradodecylammonium tetrakis(4-chlorophenyl)borate (ETH 500) is chosen as an model of IL to provide strong adhesion between the inner glassy carbon electrode and the intermediate layer. Nanomaterials including single-walled carbon nanotubes (SWCNTs) and graphene were used as active ion-to-electron transducers between the glassy carbon electrode and the ionophore-doped ISE membrane. By using the proposed approach, the solid-contact Cu{sup 2+}- and Pb{sup 2+}-selective electrodes based on ETH 500/SWCNTs and ETH 500/graphene as transducers, respectively, have been fabricated. The proposed electrodes show detection limits in the nanomolar range and exhibit a good response time and excellent stability.

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

    Directory of Open Access Journals (Sweden)

    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

  7. Multiscale imaging of carbonate rocks and representative sampling for digital rock physics

    Science.gov (United States)

    Yoon, H.; Dewers, T. A.

    2015-12-01

    Geomaterials containing nano-pores (e.g., shales and carbonate rocks) have become increasingly important for emerging problems such as unconventional gas and oil resources, enhanced oil recovery, and geologic storage of CO2. Accurate prediction of coupled geophysical and chemical processes at the pore scale requires realistic representation of pore structure and topology. This is especially true for chalk materials, where pore networks are small and complex, and require characterization at sub-micron scale. In this work, we apply laser scanning confocal microscopy with various filters to characterize pore structures and microlithofacies at a thin-section scale (micron resolution) and dual focused ion beam-scanning electron microscopy (FIB-SEM) for 3D imaging of nanometer-to-micron scale microcracks and pore distributions. With imaging techniques advanced for nano-pore characterization, it is critical to define representative sampling of FIB-SEM images and apply it to the thin-section or larger scale. In this work, several texture characterization techniques are applied for segmentation clusters represented by a couple of 3-D FIB-SEM image stacks per each cluster. Pore structure evolution is characterized based on geometric and topological properties from a set of FIB-SEM images and lattice-Boltzmann method (LBM) is used to obtain permeability at several different scales. Upscaling of permeability to the Darcy scale (e.g., the thin-section scale) with image dataset will be discussed with emphasis on understanding microfracture-matrix interaction, representative volume for FIB-SEM sampling, and multiphase flow and reactive transport. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  8. Characterisation of black carbon-rich samples by 13C solid-state nuclear magnetic resonance

    Science.gov (United States)

    Novotny, Etelvino H.; Hayes, Michael H. B.; Deazevedo, Eduardo R.; Bonagamba, Tito J.

    2006-09-01

    There are difficulties in quantifying and characterising the organic matter (OM) in soils that contain significant amounts of partially oxidised char or charcoal materials. The anthropogenic black carbon (BC), such as that found in the Terra Preta de Índio soils of the Amazon region, is a good example of the OM that is difficult to analyse in such soils. 13C direct polarisation/magic angle spinning (DP/MAS) at high MAS frequency, 1H-13C cross polarisation (CP)/MAS with total suppression of spinning sidebands (TOSS), and chemical shift anisotropy (CSA) filter nuclear magnetic resonance techniques have been applied successfully for quantifying the different components of OM. However, because pyrogenic materials present strong local magnetic susceptibility heterogeneities, the use of CSA-filter and TOSS make the pulse sequences very sensitive to imperfections in the π pulses. In this study, the DP/MAS pulse sequence was replaced by a CP with a radio frequency ramp—variable amplitude CP (VACP)—VACP/MAS pulse sequence, and composite π pulses were used in the CSA-filter and TOSS pulse sequences. In that way, the component functionalities in a humic acid from a BC soil were successfully determined. The spectrometer time needed was greatly decreased by employing this VACP/MAS technique. This development provides an accurate method for characterising BC-rich samples from different origins.

  9. Characterisation of black carbon-rich samples by (13)C solid-state nuclear magnetic resonance.

    Science.gov (United States)

    Novotny, Etelvino H; Hayes, Michael H B; Deazevedo, Eduardo R; Bonagamba, Tito J

    2006-09-01

    There are difficulties in quantifying and characterising the organic matter (OM) in soils that contain significant amounts of partially oxidised char or charcoal materials. The anthropogenic black carbon (BC), such as that found in the Terra Preta de Indio soils of the Amazon region, is a good example of the OM that is difficult to analyse in such soils. (13)C direct polarisation/magic angle spinning (DP/MAS) at high MAS frequency, (1)H-(13)C cross polarisation (CP)/MAS with total suppression of spinning sidebands (TOSS), and chemical shift anisotropy (CSA) filter nuclear magnetic resonance techniques have been applied successfully for quantifying the different components of OM. However, because pyrogenic materials present strong local magnetic susceptibility heterogeneities, the use of CSA-filter and TOSS make the pulse sequences very sensitive to imperfections in the pi pulses. In this study, the DP/MAS pulse sequence was replaced by a CP with a radio frequency ramp--variable amplitude CP (VACP)--VACP/MAS pulse sequence, and composite pi pulses were used in the CSA-filter and TOSS pulse sequences. In that way, the component functionalities in a humic acid from a BC soil were successfully determined. The spectrometer time needed was greatly decreased by employing this VACP/MAS technique. This development provides an accurate method for characterising BC-rich samples from different origins. PMID:16688435

  10. Multimedia Environmental Distribution of Nanomaterials

    Science.gov (United States)

    Liu, Haoyang Haven

    Engineered nanomaterials (ENMs), which may be released to the environment due to human-related activities, can move across environmental phase boundaries and be found in most media. Given the rapid development and growing applications of nanotechnology, there is concern and thus the need to assess the potential environmental impact associated with ENMs. Accordingly, a modeling platform was developed to enable evaluation of the dynamic multimedia environmental distribution of ENMs (MendNano) and the range of potential exposure concentrations of ENMs. The MendNano was based on a dynamic multimedia compartmental modeling approach that was guided by detailed analysis of the agglomeration of ENMs, life-cycle analysis based estimates of their potential release to the environment, and incorporation of mechanistic sub-models of various intermedia transport processes. Model simulations for various environmental scenarios indicated that ENM accumulation in the sediment increased significantly with increased ENMs attachment to suspended solids in water. Atmospheric dry and wet depositions can be important pathways for ENMs input to the terrestrial environment in the absence of direct and distributed ENM release to soil. Increased ENM concentration in water due to atmospheric deposition (wet and dry) is expected as direct ENM release to water diminishes. However, for soluble ENMs dissolution can be the dominant pathway for suspended ENM removal from water even compared to advective transport. For example, simulations for Los Angeles showed that dry deposition, rain scavenging, and wind dilution can remove 90% of ENMs from the atmospheric airshed in ~100-230 days, ~2-6 hrs, and ~0.5-2 days, respectively. For the evaluated ENMs (metal, metal oxides, carbon nanotubes (CNT), nanoclays), mass accumulation in the multimedia environment was mostly in the soil and sediment. Additionally, simulation results for TiO2 in Los Angeles demonstrates that the ENM concentrations in air and

  11. Synthesis and Characterisation of Nanomaterials

    Directory of Open Access Journals (Sweden)

    P. Saravanan

    2008-07-01

    Full Text Available Development of synthesis protocols for realising nanomaterials over a range of sizes, shapes,and chemical compositions is an important aspect of nanotechnology. The remarkable size-dependent physico-chemical properties of nanoparticles have fascinated and inspired researchactivity in this direction. This paper describes some aspects on synthesis and characterisationof nanoparticles of metals, metal alloys, and oxides, either in the form of thin films or bulk shapes.A brief discussion on processing of two-phase nanocomposite magnets is also presented.Defence Science Journal, 2008, 58(4, pp.504-516, DOI:http://dx.doi.org/10.14429/dsj.58.1671

  12. Moessbauer spectroscopy of Fe-based nanomaterials

    International Nuclear Information System (INIS)

    There are two opinions concerning the effect of the nanosized grains on magnetic properties and Moessbauer spectra. One of them testifies that nanomaterials have a grain boundary phase (interface region) which decreases the specific saturation magnetization and leads to the additional sextet in the Moessbauer spectrum. The second one treats the changes in spectra by the impurities. In this work the results on a-Fe, Fe90Ge10 and Fe77,5Al22.5 nanocrystalline alloys are presented. The nanostructured (8 nm) powders of Fe, bcc disordered Fe90Ge10 and Fe77,5Al22.5 were produced by mechanical grinding and alloying. The samples were studied by X-ray diffraction, Moessbauer spectroscopy, magnetic measurements and then compared with microstructured ones. With the absence of contamination no changes have been found in the specific saturation magnetization, Curie temperature and hyperfine interaction parameters of the nanomaterials. No additional sextet in the Moessbauer spectra and peculiarities in the temperature dependences of a.c. magnetic susceptibility were found either. We have registered a slight lines broadening (∼ 20%) in Moessbauer spectrum of the nanocrystalline pure Fe. The broadening observed is explained by random in sign and in magnitude anisotropic contribution to the hyperfine magnetic field from the Fe atoms in the interfaces. The conclusion drawn is that the interface of the nanostructure (boundary and close-to-boundary distorted zones) of 1 nm width considerably have the same magnetic properties and hyperfine interaction parameters in comparison with those in the bulk.

  13. 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.

  14. Focus on the nanomaterial-based biosensor papers in Chinese Journal of Analytical Chemistry of the year 2010

    Institute of Scientific and Technical Information of China (English)

    LIU Xia; MA LiNa; WANG ZhenXin

    2011-01-01

    Because of their unique physical and chemical properties,nanomaterials have been widely used to develop biosensing systems for bioanalytical and biomedical applications.The journal Chinese Journal of Analytical Chemistry published 35 papers on nanomaterial-based biosensors in 2010,including 5 reviews [1-5] and 29 research articles [6-34].These biosensing systems were fabricated by a broad range of nanomaterials (e.g.,carbon nanotube,gold nanoparticle,magnetic nanoparticle,silica nanoparticle,quantum dot,and so forth,Figure 1),some of them have high quality and get great achievements.

  15. Cellulose Nanomaterials in Water Treatment Technologies

    OpenAIRE

    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, ...

  16. EU and Swiss regulatory action on Nanomaterials

    OpenAIRE

    Jost, Dannie

    2012-01-01

    Dannie Jost lectured on EU and Swiss regulatory action on nanomaterials as one of 16 speakers at the interdisciplinary seminar for young scientists was aimed at doctoral students from NRP 62 "Smart Materials" and NRP 64 "Opportunities and Risks of Nanomaterials".

  17. Environmental fate and behaviour of nanomaterials

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch; Skjolding, Lars Michael; Hansen, Steffen Foss;

    In the current report, the existing knowledge on the fate of nanomaterials in the environment is reviewed and the major knowledge gaps are identified.......In the current report, the existing knowledge on the fate of nanomaterials in the environment is reviewed and the major knowledge gaps are identified....

  18. Multi-metal oxide ceramic nanomaterial

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Stephen; Liu, Shuangyi; Huang, Limin

    2016-06-07

    A convenient and versatile method for preparing complex metal oxides is disclosed. The method uses a low temperature, environmentally friendly gel-collection method to form a single phase nanomaterial. In one embodiment, the nanomaterial consists of Ba.sub.AMn.sub.BTi.sub.CO.sub.D in a controlled stoichiometry.

  19. Management of nanomaterials safety in research environment

    OpenAIRE

    Riediker Michael; Magrez Arnaud; Petri-Fink Alke; Groso Amela; Meyer Thierry

    2010-01-01

    Abstract Despite numerous discussions, workshops, reviews and reports about responsible development of nanotechnology, information describing health and environmental risk of engineered nanoparticles or nanomaterials is severely lacking and thus insufficient for completing rigorous risk assessment on their use. However, since preliminary scientific evaluations indicate that there are reasonable suspicions that activities involving nanomaterials might have damaging effects on human health; the...

  20. Thermal stability of consolidated metallic nanomaterials

    International Nuclear Information System (INIS)

    The results of applications of theoretical kinetic and thermodynamic approaches to estimation of thermal stability of consolidated nanomaterials based on various metals, alloys and refractory compounds are considered. The principal experimental data concerning the stability of the nanomaterials, including radiation stability, abnormal grain growth and oxidation, are analyzed. The bibliography includes 82 references

  1. Self-assembled nanomaterials for photoacoustic imaging

    Science.gov (United States)

    Wang, Lei; Yang, Pei-Pei; Zhao, Xiao-Xiao; Wang, Hao

    2016-01-01

    In recent years, extensive endeavors have been paid to construct functional self-assembled nanomaterials for various applications such as catalysis, separation, energy and biomedicines. To date, different strategies have been developed for preparing nanomaterials with diversified structures and functionalities via fine tuning of self-assembled building blocks. In terms of biomedical applications, bioimaging technologies are urgently calling for high-efficient probes/contrast agents for high-performance bioimaging. Photoacoustic (PA) imaging is an emerging whole-body imaging modality offering high spatial resolution, deep penetration and high contrast in vivo. The self-assembled nanomaterials show high stability in vivo, specific tolerance to sterilization and prolonged half-life stability and desirable targeting properties, which is a kind of promising PA contrast agents for biomedical imaging. Herein, we focus on summarizing recent advances in smart self-assembled nanomaterials with NIR absorption as PA contrast agents for biomedical imaging. According to the preparation strategy of the contrast agents, the self-assembled nanomaterials are categorized into two groups, i.e., the ex situ and in situ self-assembled nanomaterials. The driving forces, assembly modes and regulation of PA properties of self-assembled nanomaterials and their applications for long-term imaging, enzyme activity detection and aggregation-induced retention (AIR) effect for diagnosis and therapy are emphasized. Finally, we conclude with an outlook towards future developments of self-assembled nanomaterials for PA imaging.

  2. Recent trends in nanomaterials applications in environmental monitoring and remediation.

    Science.gov (United States)

    Das, Sumistha; Sen, Biswarup; Debnath, Nitai

    2015-12-01

    Environmental pollution is one of the greatest problems that the world is facing today, and it is increasing with every passing year and causing grave and irreparable damage to the earth. Nanomaterials, because of their novel physical and chemical characteristics, have great promise to combat environment pollution. Nanotechnology is being used to devise pollution sensor. A variety of materials in their nano form like iron, titanium dioxide, silica, zinc oxide, carbon nanotube, dendrimers, polymers, etc. are increasingly being used to make the air clean, to purify water, and to decontaminate soil. Nanotechnology is also being used to make renewable energy cheaper and more efficient. The use of nanotechnology in agriculture sector will reduce the indiscriminate use of agrochemicals and thus will reduce the load of chemical pollutant. While remediating environment pollution with nanomaterials, it should also be monitored that these materials do not contribute further degradation of the environment. This review will focus broadly on the applications of nanotechnology in the sustainable development with particular emphasis on renewable energy, air-, water-, and soil-remediation. Besides, the review highlights the recent developments in various types of nanomaterials and nanodevices oriented toward pollution monitoring and remediation. PMID:26490920

  3. Acute toxicities of six manufactured nanomaterial suspensions to Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Xiaoshan; Zhu Lin [Nankai University, Key Laboratory of Pollution Processes and Environmental Criteria (Nankai University), Ministry of Education, College of Environmental Science and Engineering (China); Chen Yongsheng, E-mail: yschen@asu.ed [Arizona State University, Department of Civil and Environmental Engineering (United States); Tian Shengyan [Tianjin University of Science and Technology, College of Marine Science and Technology (China)

    2009-01-15

    The rapid growth of nanotechnology is stimulating research on the potential environmental impacts of manufactured nanomaterials (MNMs). This paper summarizes a comprehensive study on the 48-h acute toxicity of water suspensions of six MNMs (i.e., ZnO, TiO{sub 2}, Al{sub 2}O{sub 3}, C{sub 60}, SWCNTs, and MWCNTs) to Daphnia magna, using immobilization and mortality as toxicological endpoints. The results show that the acute toxicities of all MNMs tested are dose dependent. The EC{sub 50} values for immobilization ranged from 0.622 mg/L (ZnO NPs) to 114.357 mg/L (Al{sub 2}O{sub 3} NPs), while the LC{sub 50} values for mortality ranged from 1.511 mg/L (ZnO NPs) to 162.392 mg/L (Al{sub 2}O{sub 3} NPs). In these tests, TiO{sub 2}, Al{sub 2}O{sub 3}, and carbon-based nanomaterials were more toxic than their bulk counterparts. Moreover, D. magna were found to ingest nanomaterials from the test solutions through feeding behaviors, which indicates that the potential ecotoxicities and environmental health effects of these MNMs cannot be neglected.

  4. Probing mechanical principles of cell-nanomaterial interactions

    Science.gov (United States)

    Gao, Huajian

    2014-01-01

    With the rapid development of nanotechnology, various types of nanoparticles, nanowires, nanofibers, nanotubes, and atomically thin plates and sheets have emerged as candidates for an ever increasing list of potential applications for next generation electronics, microchips, composites, barrier coatings, biosensors, drug delivery, and energy harvesting and conversion systems. There is now an urgent societal need to understand both beneficial and hazardous effects of nanotechnology which is projected to produce and release thousands of tons of nanomaterials into the environment in the coming decades. This paper aims to present an overview of some recent studies conducted at Brown University on the mechanics of cell-nanomaterial interactions, including the modeling of nanoparticles entering cells by receptor-mediated endocytosis and coarse-grained molecular dynamics simulations of nanoparticles interacting with cell membranes. The discussions will be organized around the following questions: Why and how does cellular uptake of nanoparticles depend on particle size, shape, elasticity and surface structure? In particular, we will discuss the effect of nanoparticle size on receptor-mediated endocytosis, the effect of elastic stiffness on cell-particle interactions, how high aspect ratio nanomaterials such as carbon nanotubes and graphenes enter cells and how different geometrical patterns of ligands on a nanoparticle can be designed to control the rate of particle uptake.

  5. The Role of Mobile Surface Ions in Nanomaterial Formation

    Science.gov (United States)

    Kendall, T. A.; Martin, S. T.

    2007-12-01

    Biogenic and abiotic nanomaterial formation alters the electrical layout of mineral surfaces. Complex dielectric and surface diffusional regimes that affect water sorption, metal co-precipitation, and possibly cell attachment are created. Polarization force microscopy measurements reveal the importance of mobile, surface associated ions in nanomaterial formation, particularly in subaerial conditions. Mass and charge transport between nanostructures can occur via two-dimensional diffusion of surface ions within mono- to multi-layer water. Further, nanostructure stability depends on epitaxy with the underlying substrate. On calcite under humid air, we observe the formation of a 1 to 1.5 nm thick, hydrated calcium carbonate film. This nanophase, which is typically protein- stabilized as an intermediate within biomineralization schema, is instead stabilized by the calcite 104 surface. Moreover, nanostructure dissolution on rhodochrosite is initiated by the accumulation of hydrated, edge- associated ions, most likely representing partially mobilized, positively-charged film material. We connect these molecular-level observations to large-scale, biogeophysical measurements that hold promise of remotely sensing bacteria in the subsurface (e.g., induced polarization (IP)). Here, mobile surface ion diffusion at the cell- mineral interface and biogenic nanomaterial formation are identified as key contributors to the poorly understood IP signature of bacteria in porous media.

  6. Techniques for Investigating Molecular Toxicology of Nanomaterials.

    Science.gov (United States)

    Wang, Yanli; Li, Chenchen; Yao, Chenjie; Ding, Lin; Lei, Zhendong; Wu, Minghong

    2016-06-01

    Nanotechnology has been a rapidly developing field in the past few decades, resulting in the more and more exposure of nanomaterials to human. The increased applications of nanomaterials for industrial, commercial and life purposes, such as fillers, catalysts, semiconductors, paints, cosmetic additives and drug carriers, have caused both obvious and potential impacts on human health and environment. Nanotoxicology is used to study the safety of nanomaterials and has grown at the historic moment. Molecular toxicology is a new subdiscipline to study the interactions and impacts of materials at the molecular level. To better understand the relationship between the molecular toxicology and nanomaterials, this review summarizes the typical techniques and methods in molecular toxicology which are applied when investigating the toxicology of nanomaterials and include six categories: namely; genetic mutation detection, gene expression analysis, DNA damage detection, chromosomal aberration analysis, proteomics, and metabolomics. Each category involves several experimental techniques and methods. PMID:27319209

  7. Tiny Medicine: Nanomaterial-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Nelson Watts

    2009-11-01

    Full Text Available Tiny medicine refers to the development of small easy to use devices that can help in the early diagnosis and treatment of disease. Early diagnosis is the key to successfully treating many diseases. Nanomaterial-based biosensors utilize the unique properties of biological and physical nanomaterials to recognize a target molecule and effect transduction of an electronic signal. In general, the advantages of nanomaterial-based biosensors are fast response, small size, high sensitivity, and portability compared to existing large electrodes and sensors. Systems integration is the core technology that enables tiny medicine. Integration of nanomaterials, microfluidics, automatic samplers, and transduction devices on a single chip provides many advantages for point of care devices such as biosensors. Biosensors are also being used as new analytical tools to study medicine. Thus this paper reviews how nanomaterials can be used to build biosensors and how these biosensors can help now and in the future to detect disease and monitor therapies.

  8. Nanochemistry and nanomaterials for photovoltaics.

    Science.gov (United States)

    Chen, Guanying; Seo, Jangwon; Yang, Chunhui; Prasad, Paras N

    2013-11-01

    Nanochemistry and nanomaterials provide numerous opportunities for a new generation of photovoltaics with high solar energy conversion efficiencies at low fabrication cost. Quantum-confined nanomaterials and polymer-inorganic nanocomposites can be tailored to harvest sun light over a broad range of the spectrum, while plasmonic structures offer effective ways to reduce the thickness of light-absorbing layers. Multiple exciton generation, singlet exciton fission, photon down-conversion, and photon up-conversion realized in nanostructures, create significant interest for harvesting underutilized ultraviolet and currently unutilized infrared photons. Nanochemical interface engineering of nanoparticle surfaces and junction-interfaces enable enhanced charge separation and collection. In this review, we survey these recent advances employed to introduce new concepts for improving the solar energy conversion efficiency, and reduce the device fabrication cost in photovoltaic technologies. The review concludes with a summary of contributions already made by nanochemistry. It then describes the challenges and opportunities in photovoltaics where the chemical community can play a vital role.

  9. Comparison of ORNL Low Cost Carbon Fiber with Commercially Available Industrial Grade Carbon Fiber in Pultrusion Samples

    Energy Technology Data Exchange (ETDEWEB)

    Norris, Jr, Robert E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McCay, Jeff A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Connie D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-02-01

    Composite Applications Group LLC in collaboration with Heil Trailer International partnered in a project to design and develop solutions for light weighting of aluminum dry bulk tank trailers. The project approach was to utilize pultruded composite sections in place of aluminum components to reduce weight thereby saving energy through more efficient transport. Low cost carbon fiber was evaluated as a potential cost saving option that could enhance weight savings at reduced cost versus current commercial material.

  10. MCNP ESTIMATE OF THE SAMPLED VOLUME IN A NON-DESTRUCTIVE IN SITU SOIL CARBON ANALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    WIELOPOLSKI, L.; DIOSZEGI, I.; MITRA, S.

    2004-05-03

    Global warming, promoted by anthropogenic CO{sub 2} emission into the atmosphere, is partially mitigated by the photosynthesis processes of the terrestrial echo systems that act as atmospheric CO{sub 2} scrubbers and sequester carbon in soil. Switching from till to no till soils management practices in agriculture further augments this process. Carbon sequestration is also advanced by putting forward a carbon ''credit'' system whereby these can be traded between CO{sub 2} producers and sequesters. Implementation of carbon ''credit'' trade will be further promulgated by recent development of a non-destructive in situ carbon monitoring system based on inelastic neutron scattering (INS). Volumes and depth distributions defined by the 0.1, 1.0, 10, 50, and 90 percent neutron isofluxes, from a point source located at either 5 or 30 cm above the surface, were estimated using Monte Carlo calculations.

  11. Synthesis, structural characterisation and antibacterial activity of Ag{sup +}-doped fluorapatite nanomaterials prepared by neutralization method

    Energy Technology Data Exchange (ETDEWEB)

    Stanić, Vojislav, E-mail: voyo@vinca.rs [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia); Radosavljević-Mihajlović, Ana S. [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia); Živković-Radovanović, Vukosava [University of Belgrade, Faculty of Chemistry, P.O. Box 51, 11158 Belgrade (Serbia); Nastasijević, Branislav; Marinović-Cincović, Milena; Marković, Jelena P.; Budimir, Milica D. [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia)

    2015-05-15

    Graphical abstract: - Highlights: • The neutralization method has been used for synthesis of silver-doped fluorapatite powders. • Particles of silver-doped fluorapatite samples are of nano size and homogenous in composition. • The Ag{sup +}-doped fluorapatite samples showed antibacterial effect against Kllebsiela pneumoniae, Staphylococcus aureus and Micrococcus luteus. • AFM studies showed that silver-doped sample causes considerable morphological changes of tested bacterial cells. - Abstract: Silver doped fluorapatite nanopowders were synthesised by neutralization method, which consists of dissolving Ag{sub 2}O in solution of HF and H{sub 3}PO{sub 4} and addition to suspension of Ca(OH){sub 2}. The powder XRD, SEM and FTIR studies indicated the formation of a fluorapatite nanomaterials with average length of the particles is about 80 nm and a width of about 15 nm. The FTIR studies show that carbonate content in samples is very small and carbonte ions substitute both phosphate and hydroxyl groups in the crystal structure of samples, forming AB-type fluorapatite. Antibacterial studies have demonstrated that all Ag{sup +}-doped fluorapatite samples exhibit bactericidal effect against pathogens: Staphylococcus aureus, Micrococcus luteus and Kllebsiela pneumoniae. Antibacterial activity increased with the increase of Ag{sup +} in the samples. The atomic force microscopy studies revealed extensive damage to the bacterial cell envelops in the presence of Ag{sup +}-doped fluorapatite particles which may lead to their death. The synthesized Ag{sup +}-doped fluorapatite nanomaterials are promising as antibacterial biomaterials in orthopedics and dentistry.

  12. CARBONIZED FIBROUS RESIN AS A NEW SORBENT FOR SAMPLING POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)IN AMBIENT AIR

    Institute of Scientific and Technical Information of China (English)

    LINGDaren; LIUBing; 等

    2002-01-01

    A new sampling method of ambient air analysis using carbonized fibrous resin as a sorbent for polycyclic aromatic hydrocarbons(PAHs) was reported.The physical and chemical properties of the carbonized fibrous resins were measured.The sample pretreatment with ultrasonic extraction and subsequent clean-up elution through a silica gel column was optimized.The suitable ultrasonic extraction conditions were selected as follows:resin weight was 1.5g,ultrasonic extraction time 20min,volume of extraction solvent 100 ml and extraction operation times 2-3.The concentrated extractable organic matter was submitted to next step of clean-up procedure of adsorption chromatography on silica gel column/n-hexane and a mixture of dichloromethene:n-hexane solution 2:3(v/v).The PAHs fractions in the real samples from Changzhou,China were particularly analyzed using GC-MS data system and the data of mass spectra,retention times and scan numbers of the real samples were compared with that of the standards of 16 PAHs listed by the US EPA as “priority pollutants” of the environment. The pretreatment of samples of ambient air with carbonized fibrous resin as a sorbent for PAHs is proved to be reliable and might be used for the procedure of the determination of PAHs in atmospheric environment.

  13. Molecular carbon isotope variations in core samples taken at the Permian-Triassic boundary layers in southern China

    Science.gov (United States)

    Wang, Ruiliang; Zhang, Shuichang; Brassell, Simon; Wang, Jiaxue; Lu, Zhengyuan; Ming, Qingzhong; Wang, Xiaomei; Bian, Lizeng

    2012-07-01

    Stable carbon isotope composition (δ13C) of carbonate sediments and the molecular (biomarker) characteristics of a continuous Permian-Triassic (PT) layer in southern China were studied to obtain geochemical signals of global change at the Permian-Triassic boundary (PTB). Carbonate carbon isotope values shifted toward positive before the end of the Permian period and then shifted negative above the PTB into the Triassic period. Molecular carbon isotope values of biomarkers followed the same trend at and below the PTB and remained negative in the Triassic layer. These biomarkers were acyclic isoprenoids, ranging from C15 to C40, steranes (C27 dominates) and terpenoids that were all significantly more abundant in samples from the Permian layer than those from the Triassic layer. The Triassic layer was distinguished by the dominance of higher molecular weight (waxy) n-alkanes. Stable carbon isotope values of individual components, including n-alkanes and acyclic isoprenoids such as phytane, isop-C25, and squalane, are depleted in δ13C by up to 8-10‰ in the Triassic samples as compared to the Permian. Measured molecular and isotopic variations of organic matter in the PT layers support the generally accepted view of Permian oceanic stagnation followed by a massive upwelling of toxic deep waters at the PTB. A series of large-scale (global) outgassing events may be associated with the carbon isotope shift we measured. This is also consistent with the lithological evidence we observed of white thin-clay layers in this region. Our findings, in context with a generally accepted stagnant Permian ocean, followed by massive upwelling of toxic deep waters might be the major causes of the largest global mass extinction event that occurred at the Permian-Triassic boundary.

  14. Nanomaterial Synthesis Using Plasma Generation in Liquid

    Directory of Open Access Journals (Sweden)

    Genki Saito

    2015-01-01

    Full Text Available Over the past few decades, the research field of nanomaterials (NMs has developed rapidly because of the unique electrical, optical, magnetic, and catalytic properties of these materials. Among the various methods available today for NM synthesis, techniques for plasma generation in liquid are relatively new. Various types of plasma such as arc discharge and glow discharge can be applied to produce metal, alloy, oxide, inorganic, carbonaceous, and composite NMs. Many experimental setups have been reported, in which various parameters such as the liquid, electrode material, electrode configuration, and electric power source are varied. By examining the various electrode configurations and power sources available in the literature, this review classifies all available plasma in liquid setups into four main groups: (i gas discharge between an electrode and the electrolyte surface, (ii direct discharge between two electrodes, (iii contact discharge between an electrode and the surface of surrounding electrolyte, and (iv radio frequency and microwave plasma in liquid. After discussion of the techniques, NMs of metal, alloy, oxide, silicon, carbon, and composite produced by techniques for plasma generation in liquid are presented, where the source materials, reaction media, and electrode configurations are discussed in detail.

  15. Nanomaterials to Combat NO(x) Pollution.

    Science.gov (United States)

    Balbuena, J; Cruz-Yusta, M; Sánchez, L

    2015-09-01

    The presence of NO9x) gases (NO+NO2) in the atmosphere is a major concern of society because of their associated adverse and harmful effects. In order to remove the NO(x) gases from the air, photocatalysis arises as an innovative and promising technique. Through the use of photochemical oxidation processes the NO and NO2 gases are oxidised to NO3- form and thus removed from the air. In recent years new nanomaterials are being developed by researchers with the aim to enhance their photocatalytic activity to combat the NO(x) pollution. The main focus is devoted to preparing new TiO2 based compounds with the highest specific surface area (SSA), different morphology and chemical modifications. In order to increase the SSA, different substrates were used to disperse the TiO2 nanoparticles: organic and carbon fibres, mesoporous materials, clays composites and nanoporous microparticles. In the other hand, high photocatalytic performances were obtained with nanotubes, self-orderer nano-tubular films and nanoparticles with the lowest size. Conversely, when TiO2 is doped with ions the oxide exhibited a better photocatalytic performance under visible light, which is related to the creation of intermediate energy states between the conduction band and the valence band. Alternatively, visible light photocatalysts different from titanium oxide have been studied, which exhibit a good De-NO(x) efficiency working under λ > 400 nm visible light irradiation.

  16. Carbon XANES Data from Six Aerogel Picokeystones Cut from the Top and Bottom Sides of the Stardust Comet Sample Tray

    Science.gov (United States)

    Wirick, S.; Flynn, G. J.; Frank, D.; Sandford, S. A.; Zolensky, M. E.; Tsou, P.; Peltzer, C.; Jacobsen, C.

    2009-01-01

    Great care and a large effort was made to minimize the amount of organic matter contained within the flight aerogel used to collect Comet 81P/Wild 2 samples. Even so, by the very nature of the production process and silica aerogel s affinity for volatile organics keeping silica aerogel free from organics is a monumental task. Silica aerogel from three production batches was flown on the Stardust sample return mission. All 3 types had layered densities varying from 5mg/ml to 50 mg/ml where the densest aerogel was farthest away from the collection area. A 2 step gelation process was used to make the flight aerogel and organics used in this process were tetraethylorthosilicate, ethanol and acetonitrile. Both ammonium hydroxide and nitric acid were also used in the aerogel production process. The flight aerogel was baked at JPL at 300 C for 72 hours, most of the baking was done at atmosphere but twice a day the oven was pumped to 10 torr for hour [1]. After the aerogel was baked it was stored in a nitrogen purged cabinet until flight time. One aerogel cell was located in the SRC away from any sample collection area as a witness to possible contamination from out gassing of the space craft, re-entry gases and any other organic encounter. This aerogel was aerogel used in the interstellar collection sample tray and is the least dense of the 3 batches of aerogel flown. Organics found in the witness tile include organics containing Si-CH3 bonds, amines and PAHS. Besides organic contamination, hot spots of calcium were reported in the flight aerogel. Carbonates have been detected in comet 81P/Wild2 samples . During preflight analyses, no technique was used to analyze for carbonates in aerogel. To determine if the carbonates found in 81P/Wild2 samples were from the comet, it is necessary to analyze the flight aerogel for carbonate as well as for organics.

  17. Use of Homogeneously-Sized Carbon Steel Ball Bearings to Study Microbially-Influenced Corrosion in Oil Field Samples

    OpenAIRE

    Gerrit eVoordouw; Priyesh eMenon; Tijan ePinnock; Mohita eSharma; Yin eShen; Amanda eVenturelli; Johanna eVoordouw; Aoife eSexton

    2016-01-01

    Microbially-influenced corrosion (MIC) contributes to the general corrosion rate (CR), which is typically measured with carbon steel coupons. Here we explore the use of carbon steel ball bearings, referred to as beads (55.0 ± 0.3 mg; Ø = 0.238 cm), for determining CRs. CRs for samples from an oil field in Oceania incubated with beads were determined by the weight loss method, using acid treatment to remove corrosion products. The release of ferrous and ferric iron was also measured and CRs ba...

  18. Identifying Minimum Detectable Change in US Forest Soil Carbon under the Forest Inventory Analysis (FIA) Sampling Strategy

    Science.gov (United States)

    Wu, A. M.; Nater, E. A.; Perry, C. H.; Dalzell, B. J.; Wilson, B.

    2015-12-01

    Estimates of carbon stocks and stock changes in the U.S. Department of Agriculture Forest Service's Forest Inventory and Analysis (FIA) Program are reported as the official United States submission to the UN Framework Convention on Climate Change. Soil, as a critical component of the forest carbon stocks, has been sampled in about 10-year intervals in FIA with the re-measurement underway. However, the magnitude of detectable change in soil organic carbon (SOC) with the current sampling scheme is unknown. We aim to identify SOC variability and to best determine minimum detectable changes in SOC under the current sampling scheme. The project seeks to: identify statistical relationships between SOC and environmental covariates; normalize SOC data for main forest-type groups (FTGs) using identified covariates; and determine the minimum detectable change in the normalized SOC using power analysis. We investigated SOC variability for 8 FTGs: Oak-Hickory, Maple-Beech-Birch, Pinyon-Juniper, Loblolly-Shortleaf Pine, Aspen-Birch, Douglas-Fir, Fir-Spruce-Mountain Hemlock and Woodland Hardwoods. Relationships between SOC and environmental covariates (biomass/soil properties in FIA, PRISM climate data, and DEM-derived terrain attributes) are determined by multiple linear regression and are used to normalize SOC variability. The results showed that terrain attributes were not significant in explaining SOC in the FIA dataset and climate data were only significant in certain FTGs locations. Except for Oak-Hickory, Maple-Beech-Birch and Pinyon-Juniper groups, sample numbers are insufficient to detect a change in SOC less than 10 percent (%) of the mean. To guide future sampling efforts, we will continue our study on detecting minimal change in SOC and to explore sample number and sampling frequency scenarios to inform future soil sampling protocols.

  19. Nanomaterials for Advanced Life Support in Advanced Life Support in Space systems

    Science.gov (United States)

    Allada, Rama Kumar; Moloney, Padraig; Yowell, Leonard

    2006-01-01

    A viewgraph presentation describing nanomaterial research at NASA Johnson Space Center with a focus on advanced life support in space systems is shown. The topics include: 1) Introduction; 2) Research and accomplishments in Carbon Dioxide Removal; 3) Research and Accomplishments in Water Purification; and 4) Next Steps

  20. EDITORIAL: Excelling under strain: band engineering in nanomaterials Excelling under strain: band engineering in nanomaterials

    Science.gov (United States)

    Demming, Anna

    2013-08-01

    interest in strain studies as well. Researchers in China investigated the effects of tensile strain on the thermal conductivity of graphene nanoribbons. Tuning the thermal conductivity of nanomaterials is highly desirable to optimize their functionality [5]. Wei and colleagues use computer simulations based on reverse nonequilibrium molecular dynamics (RNEMD) to demonstrate what they describe as 'a strain-induced magic flexibility of thermal engineering for carbon-based nanostructures', which may provide a new approach for tailoring nanomaterial functionality. Despite the attractions of more recently discovered carbon nanomaterials silicon remains the bedrock of the semiconductor device industry. Germanium nanostructures also hold significant interest, such as Ge nanowires, which have high mobility and a conveniently low synthesis temperature [6]. In fact the potential applications of germanium nanowires in field effect transistors and nanobridge devices prompted Jagadish and colleagues in Australia, Korea and the UK to investigate the growth of taper-free kinked Ge nanowires in silicon [7]. As they point out many recent reports have highlighted such kinked nanowires as valuable components for novel nanodevices. The work reported by Hrauda and colleagues in this issue looks at the growth of germanium islands on a silicon substrate rather than nanowires [2]. They grow islands on pre-patterned silicon with different levels of Ge deposition with the aim of better understanding how to manage the effects of strain due to lattice mismatch between the two metals. Their results show that considerably more Ge can be deposited without dislocations forming than previously thought and reveal a distinctive cycle of changing island morphologies as Ge is deposited. They add, 'Strain relaxation is revealed to be the main driving force of a rather complex evolution of island shape and Ge distribution'. In reference to his theory of atoms Bohr is once said to have told Werner Heisenberg

  1. Enhancing thermal conductivity of fluids with graphite nanoparticles and carbon nanotube

    Science.gov (United States)

    Zhang, Zhiqiang; Lockwood, Frances E.

    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.

  2. Piezoelectric nanomaterials for biomedical applications

    CERN Document Server

    Menciassi, Arianna

    2012-01-01

    Nanoscale structures and materials have been explored in many biological applications because of their novel and impressive physical and chemical properties. Such properties allow remarkable opportunities to study and interact with complex biological processes. This book analyses the state of the art of piezoelectric nanomaterials and introduces their applications in the biomedical field. Despite their impressive potentials, piezoelectric materials have not yet received significant attention for bio-applications. This book shows that the exploitation of piezoelectric nanoparticles in nanomedicine is possible and realistic, and their impressive physical properties can be useful for several applications, ranging from sensors and transducers for the detection of biomolecules to “sensible” substrates for tissue engineering or cell stimulation.

  3. Determination of cadmium and lead in urine samples after dispersive solid–liquid extraction on multiwalled carbon nanotubes by slurry sampling electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A new method for the determination of Cd and Pb in urine samples has been developed. The method involves dispersive solid-phase extraction (DSPE), slurry sampling (SS), and subsequent electrothermal atomic absorption spectrometry (ETAAS). Oxidized multiwalled carbon nanotubes (MWCNTs) were used as the sorbent material. The isolated MWCNT/analyte aggregates were treated with nitric acid to form a slurry and both metals were determined directly by injecting the slurry into the ETAAS-atomizer. The parameters that influence the adsorption of the metals on MWCNTs in the DSPE process, the formation and extraction of the slurry, and the ETAAS conditions were studied by different factorial design strategies. The detection and quantification limits obtained for Cd under optimized conditions were 9.7 and 32.3 ng L−1, respectively, and for Pb these limits were 0.13 and 0.43 μg L−1. The preconcentration factors achieved were 3.9 and 5.4. The RSD values (n = 10) were less than 4.1% and 5.9% for Cd and Pb, respectively. The accuracy of the method was assessed in recovery studies, with values in the range 96–102% obtained for Cd and 97–101% for Pb. In addition, the analysis of certified reference materials gave consistent results. The DSPE–SS–ETAAS method is a novel and useful strategy for the determination of Pb and Cd at low levels in human urine samples. The method is sensitive, fast, and free of matrix interferences, and it avoids the tedious and time-consuming on-column adsorption and elution steps associated with commonly used SPE procedures. The proposed method was used to determine Cd and Pb in urine samples of unexposed healthy people and satisfactory results were obtained. - Highlights: • Cd and Pb determination based on the combination of DSP, SS and ETAAS • Urine matrix was eliminated using DSPE based on multiwalled carbon nanotubes. • Slurry sampling technique permitted the direct injection of sample into the ETAAS atomizer. • Appropriate

  4. Determination of cadmium and lead in urine samples after dispersive solid–liquid extraction on multiwalled carbon nanotubes by slurry sampling electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Álvarez Méndez, J.; Barciela García, J.; García Martín, S.; Peña Crecente, R.M.; Herrero Latorre, C., E-mail: carlos.herrero@usc.es

    2015-04-01

    A new method for the determination of Cd and Pb in urine samples has been developed. The method involves dispersive solid-phase extraction (DSPE), slurry sampling (SS), and subsequent electrothermal atomic absorption spectrometry (ETAAS). Oxidized multiwalled carbon nanotubes (MWCNTs) were used as the sorbent material. The isolated MWCNT/analyte aggregates were treated with nitric acid to form a slurry and both metals were determined directly by injecting the slurry into the ETAAS-atomizer. The parameters that influence the adsorption of the metals on MWCNTs in the DSPE process, the formation and extraction of the slurry, and the ETAAS conditions were studied by different factorial design strategies. The detection and quantification limits obtained for Cd under optimized conditions were 9.7 and 32.3 ng L{sup −1}, respectively, and for Pb these limits were 0.13 and 0.43 μg L{sup −1}. The preconcentration factors achieved were 3.9 and 5.4. The RSD values (n = 10) were less than 4.1% and 5.9% for Cd and Pb, respectively. The accuracy of the method was assessed in recovery studies, with values in the range 96–102% obtained for Cd and 97–101% for Pb. In addition, the analysis of certified reference materials gave consistent results. The DSPE–SS–ETAAS method is a novel and useful strategy for the determination of Pb and Cd at low levels in human urine samples. The method is sensitive, fast, and free of matrix interferences, and it avoids the tedious and time-consuming on-column adsorption and elution steps associated with commonly used SPE procedures. The proposed method was used to determine Cd and Pb in urine samples of unexposed healthy people and satisfactory results were obtained. - Highlights: • Cd and Pb determination based on the combination of DSP, SS and ETAAS • Urine matrix was eliminated using DSPE based on multiwalled carbon nanotubes. • Slurry sampling technique permitted the direct injection of sample into the ETAAS atomizer.

  5. Evaluation of pulmonary and systemic toxicity following lung exposure to graphite nanoplates: a member of the graphene-based nanomaterial family

    OpenAIRE

    Roberts, Jenny R; Mercer, Robert R; Stefaniak, Aleksandr B; Seehra, Mohindar S.; Geddam, Usha K.; Chaudhuri, Ishrat S.; Kyrlidis, Angelos; Kodali, Vamsi K.; Sager, Tina; Kenyon, Allison; Bilgesu, Suzan A; Eye, Tracy; Scabilloni, James F; Leonard, Stephen S.; Natalie R. Fix

    2016-01-01

    Background Graphene, a monolayer of carbon, is an engineered nanomaterial (ENM) with physical and chemical properties that may offer application advantages over other carbonaceous ENMs, such as carbon nanotubes (CNT). The goal of this study was to comparatively assess pulmonary and systemic toxicity of graphite nanoplates, a member of the graphene-based nanomaterial family, with respect to nanoplate size. Methods Three sizes of graphite nanoplates [20 μm lateral (Gr20), 5 μm lateral (Gr5), an...

  6. A global view of regulations affecting nanomaterials

    DEFF Research Database (Denmark)

    Hansen, Steffen Foss

    2010-01-01

    or are soft law initiatives, and their impact on the development of more authoritative and prescriptive regulatory measures is most likely to be limited. This is due to a number of transnational regulatory challenges that include: (1) whether to adapt existing legislation or develop a new regulatory framework......, (2) whether nanomaterials should be considered as different from their bulk counterparts, (3) how to define nanotechnology and nanomaterials, and (4) how to deal with the profound limitations of risk assessment when it comes to nanomaterials. In this opinion, I discuss these and related issues...

  7. 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.

  8. Electrical properties of carbon nanotubes in flowing vapor

    Institute of Scientific and Technical Information of China (English)

    XIAO Peng; WANG Xin-qiang; ZHANG Yun-huai

    2006-01-01

    Electric potentials were generated from carbon nanotubes immersed in flowing vapors.The nanomaterials used in this study were multiwall carbon nanotubes(MWCNTs) and silver nanopowders.These nanomaterials were dispersed and densely packed on a substrate and immersed in flowing vapors generated from solution such as water,ethanol and KCl.The potentials generated from these samples were measured by a voltmeter.Experimental results showed that the electric potentials were produced at the surface of the MWCNT samlpes,and strongly dependent on the pretreatment of MWCNT and properties of the flowing vapors.The mechanism of vapor-flow induced potentials may be ascribed to ions in the flowing vapors.This property of MWCNTs can advantage their application to nanoscale sensors,detectors and power cells.

  9. Method for synthesizing carbon nanotubes

    Science.gov (United States)

    Fan, Hongyou

    2012-09-04

    A method for preparing a precursor solution for synthesis of carbon nanomaterials, where a polar solvent is added to at least one block copolymer and at least one carbohydrate compound, and the precursor solution is processed using a self-assembly process and subsequent heating to form nanoporous carbon films, porous carbon nanotubes, and porous carbon nanoparticles.

  10. Limitations and information needs for engineered nanomaterial-specific exposure estimation and scenarios: recommendations for improved reporting practices

    International Nuclear Information System (INIS)

    The aim of this paper is to describe the process and challenges in building exposure scenarios for engineered nanomaterials (ENM), using an exposure scenario format similar to that used for the European Chemicals regulation (REACH). Over 60 exposure scenarios were developed based on information from publicly available sources (literature, books, and reports), publicly available exposure estimation models, occupational sampling campaign data from partnering institutions, and industrial partners regarding their own facilities. The primary focus was on carbon-based nanomaterials, nano-silver (nano-Ag) and nano-titanium dioxide (nano-TiO2), and included occupational and consumer uses of these materials with consideration of the associated environmental release. The process of building exposure scenarios illustrated the availability and limitations of existing information and exposure assessment tools for characterizing exposure to ENM, particularly as it relates to risk assessment. This article describes the gaps in the information reviewed, recommends future areas of ENM exposure research, and proposes types of information that should, at a minimum, be included when reporting the results of such research, so that the information is useful in a wider context.

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

    OpenAIRE

    VLASOV Vladimir Alexeevich

    2015-01-01

    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...

  12. Determination of mutagenic amines in water and food samples by high pressure liquid chromatography with amperometric detection using a multiwall carbon nanotubes-glassy carbon electrode.

    Science.gov (United States)

    Bueno, Ana María; Marín, Miguel Ángel; Contento, Ana María; Ríos, Ángel

    2016-02-01

    A chromatographic method, using amperometric detection, for the sensitive determination of six representative mutagenic amines was developed. A glassy carbon electrode (GCE), modified with multiwall carbon nanotubes (GCE-CNTs), was prepared and its response compared to a conventional glassy carbon electrode. The chromatographic method (HPLC-GCE-CNTs) allowed the separation and the determination of heterocyclic aromatic amines (HAAs) classified as mutagenic amines by the International Agency for Research of Cancer. The new electrode was systematically studied in terms of stability, sensitivity, and reproducibility. Statistical analysis of the obtained data demonstrated that the modified electrode provided better sensitivity than the conventional unmodified ones. Detection limits were in the 3.0 and 7.5 ng/mL range, whereas quantification limits ranged between 9.5 and 25.0 ng/mL were obtained. The applicability of the method was demonstrated by the determination of the amines in several types of samples (water and food samples). Recoveries indicate very good agreement between amounts added and those found for all HAAs (recoveries in the 92% and 105% range).

  13. Determination of mutagenic amines in water and food samples by high pressure liquid chromatography with amperometric detection using a multiwall carbon nanotubes-glassy carbon electrode.

    Science.gov (United States)

    Bueno, Ana María; Marín, Miguel Ángel; Contento, Ana María; Ríos, Ángel

    2016-02-01

    A chromatographic method, using amperometric detection, for the sensitive determination of six representative mutagenic amines was developed. A glassy carbon electrode (GCE), modified with multiwall carbon nanotubes (GCE-CNTs), was prepared and its response compared to a conventional glassy carbon electrode. The chromatographic method (HPLC-GCE-CNTs) allowed the separation and the determination of heterocyclic aromatic amines (HAAs) classified as mutagenic amines by the International Agency for Research of Cancer. The new electrode was systematically studied in terms of stability, sensitivity, and reproducibility. Statistical analysis of the obtained data demonstrated that the modified electrode provided better sensitivity than the conventional unmodified ones. Detection limits were in the 3.0 and 7.5 ng/mL range, whereas quantification limits ranged between 9.5 and 25.0 ng/mL were obtained. The applicability of the method was demonstrated by the determination of the amines in several types of samples (water and food samples). Recoveries indicate very good agreement between amounts added and those found for all HAAs (recoveries in the 92% and 105% range). PMID:26304357

  14. Optimizing sample pretreatment for compound-specific stable carbon isotopic analysis of amino sugars in marine sediment

    Directory of Open Access Journals (Sweden)

    R. Zhu

    2014-01-01

    Full Text Available Amino sugars are quantitatively significant constituents of soil and marine sediment, but their sources and turnover in environmental samples remain poorly understood. The stable carbon isotopic composition of amino sugars can provide information on the lifestyles of their source organisms and can be monitored during incubations with labeled substrates to estimate the turnover rates of microbial populations. However, until now, such investigation has been carried out only with soil samples, partly because of the much lower abundance of amino sugars in marine environments. We therefore optimized a procedure for compound-specific isotopic analysis of amino sugars in marine sediment employing gas chromatography-isotope ratio mass spectrometry. The whole procedure consisted of hydrolysis, neutralization, enrichment, and derivatization of amino sugars. Except for the derivatization step, the protocol introduced negligible isotopic fractionation, and the minimum requirement of amino sugar for isotopic analysis was 20 ng, i.e. equivalent to ~ 8 ng of amino sugar carbon. Our results obtained from δ13C analysis of amino sugars in selected marine sediment samples showed that muramic acid had isotopic imprints from indigenous bacterial activities, whereas glucosamine and galactosamine were mainly derived from organic detritus. The analysis of stable carbon isotopic compositions of amino sugars opens a promising window for the investigation of microbial metabolisms in marine sediments and the deep marine biosphere.

  15. Mechanical characterization of low dimensional nanomaterials and polymer nanocomposites

    Science.gov (United States)

    Gao, Hongsheng

    This research was aimed to characterize the mechanical properties of low dimensional nanomaterials and polymer nanocomposites, and to study the reinforcing mechanisms of nanoscale reinforcements. The nanomaterials studied were zero-dimensional nanomaterial--cuprous oxide (Cu2O) nanocubes, one-dimensional nanomaterials--silver nanowires and silicon oxide (SiO2) nanowires, and two-dimensional nanomaterial--nanometer-thick montmorillonite clay platelets. The hardness and elastic moduli of solid Cu 2O nanocubes and silver nanowires were measured by directly indenting individual cubes/wires using a nanoindenter. The elastic modulus of amorphous SiO2 nanowires was measured by performing three-point bending on suspended wires with an atomic force microscope (AFM) tip. The elastic modulus of the nanometer-thick clay platelets was assessed by the modulus mapping technique. An array of nanoscale indents was successfully made on a nanowire. The nanowires were cut to the length as needed. The nanoindentation approach permits the direct machining of individual nanowires without complications of conventional lithography. The nanomechanical properties of single-walled carbon nanotube (SWCNT)-reinforced epoxy composites with varying nanotube concentrations were measured by nanoindentation/nanoscratch techniques. Hardness and elastic modulus were measured using a nanoindenter. Viscoelastic properties of the nanocomposites were measured using nanoindentation dynamic mechanical analysis tests. The SWCNT reinforcing mechanisms were further studied by both Halpin-Tsai and Mori-Tanaka theories, which were found applicable to SWCNT-reinforced, amorphous-polymer composites. The possible reinforcing mechanisms that work in polymer-SWCNT composites and reasons responsible for SWCNTs' low mechanical reinforcement were analyzed. Nanoclay-reinforced agarose nanocomposites with varying clay concentrations were structurally and mechanically characterized. Structural characterization was carried

  16. Estimation model of Cs-137 activity in soil samples derives from percentage of organic carbon and silt-clay

    International Nuclear Information System (INIS)

    Estimation of Cs-137 activity in soil samples was conducted at Nganjuk area through its soil organic carbon and silt-clay percentage. Twenty-six soil samples taken from Nganjuk area have been used to establish the relationship of Cs-137 activity and its soil samples quality parameters by using SPSS (Statistical Product and Service Solutions) software. Chemical parameters of samples have higher variation compared to the physical. Estimated of Cs-137 activity in soil samples can be established by two parameters, those are percent of total organic carbon and percent of silt-clay contents. However, these two parameters could only explained 69.3 % of Cs-137 activity, the remaining 30.7 % potentially could be due to 10 % of error measurement, run-on redistribution of soil, farming as well as tillage system. By using the soil quality parameters, the Cs-137 activity under the limit detection could be estimated, hence, its usefulness to estimate the erosion rate through applying the Cs-model. (author)

  17. Atmospheric carbon diooxide mixing ratios from the NOAA Climate Monitoring and Diagnostics Laboratory cooperative flask sampling network, 1967-1993

    Energy Technology Data Exchange (ETDEWEB)

    Conway, T.J.; Tans, P.P. [National Oceanic and Atmospheric Administration, Boulder, CO (United States); BBoden, T.A. [Oak Ridge National Lab., TN (United States)

    1996-02-01

    This data report documents monthly atmospheric CO{sub 2} mixing ratios and measurements obtained by analyzing individual flask air samples for the NOAA/CMDL global cooperative flask sampling network. Measurements include land-based sampling sites and shipboard measurements covering 14 latitude bands in the Pacific Ocean and South China Sea. Analysis of the NOAA/CMDL flask CO{sub 2} database shows a long-term increase in atmospheric CO{sub 2} mixing ratios since the late 1960s. This report describes how the samples are collected and analyzed and how the data are processed, defines limitations, and restrictions of the data, describes the contents and format of the data files, and provides tabular listings of the monthly carbon dioxide records.

  18. Recent Applications of Nanomaterials in Prosthodontics

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2015-01-01

    Full Text Available In recent years, lots of researches have been launched on nanomaterials for biomedical applications. It has been shown that the performances of many biomaterials used in prosthodontics have been significantly enhanced after their scales were reduced by nanotechnology, from micron-size into nanosize. On the other hand, many nanocomposites composed of nanomaterials and traditional metals, ceramics, resin, or other matrix materials have been widely used in prosthodontics because their properties, such as modulus elasticity, surface hardness, polymerization shrinkage, and filler loading, were significantly increased after the addition of the nanomaterials. In this paper, the latest research progress on the applications of nanometals, nanoceramic materials, nanoresin materials, and other nanomaterials in prosthodontics was reviewed, which not only gives a detailed description of the new related investigations, but also hopefully provides important elicitation for future researches in this field.

  19. Assessing the Environmental Safety of Engineered Nanomaterials

    Science.gov (United States)

    Nanotechnology research in the United States is coordinated under the National Nano-technology Initiative with the goal of fostering development and implementation of nanomaterials and products that incorporate them and assuring that they are environmentally safe. The environmen...

  20. 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 ...

  1. Elemental Analysis of Nanomaterial Using Photon-Atom Interaction Based EDXRF Technique

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2013-08-01

    Full Text Available Presence of trace amount of foreign impurities (both metallic and non-metallic in standard salts used for sample preparation and during the synthesis process can alter the physical and chemical behavior of the pure and doped nano-materials. Therefore, it becomes important to determine concentration of various elements present in synthesized nano-material sample. In present work, the elemental and compositional analysis of nano-materials synthesized using various methods has been performed using photon-atom interaction based energy dispersive x-ray fluorescence (EDXRF technique. This technique due to its multielement analytical capability, lower detection limit, capability to analyze metals and non-metals alike and almost no sample preparation requirements can be utilized for analysis of nano-materials. The EDXRF spectrometer involves a 2.4 kW Mo anode x-ray tube (Pananalytic, Netherland equipped with selective absorbers as an excitation source and an LEGe detector (FWHM = 150 eV at 5.895 keV, Canberra, US coupled with PC based multichannel analyzer used to collect the fluorescentx-ray spectra. The analytical results showed good agreements with the expected values calculated on the basis of the precursor used in preparation of nano-materials.

  2. Comparision of carbon dioxide-baited trapping systems for sampling outdoor mosquito populations in Tanzania

    NARCIS (Netherlands)

    Mboera, L.E.G.; Knols, B.G.J.; Braks, M.A.H.; Takken, W.

    2000-01-01

    For collecting mosquitoes (Diptera: Culicidae) the outdoor catching efficiency of four types of trapping devices baited with carbon dioxide (CO2, 300 ml/min) was evaluated and compared in two areas of Tanzania. The types of traps employed were: the CDC miniature trap with the incandescent light bulb

  3. EMERGING MODALITES FOR SOIL CARBON ANALYSIS: SAMPLING STATISTICS AND ECONOMICS WORKSHOP

    Science.gov (United States)

    Carbon is an integral part of the global C cycle and plays an important role in soil quality and productivity. In the last 20-30 years detailed knowledge of C balances and transport in the soil, on local, regional, and global scales emerged as being critically important for quantification of soil C ...

  4. Nanomaterials for Cardiac Myocyte Tissue Engineering

    OpenAIRE

    Rodolfo Amezcua; Ajay Shirolkar; Carolyn Fraze; David A. Stout

    2016-01-01

    Since their synthesizing introduction to the research community, nanomaterials have infiltrated almost every corner of science and engineering. Over the last decade, one such field has begun to look at using nanomaterials for beneficial applications in tissue engineering, specifically, cardiac tissue engineering. During a myocardial infarction, part of the cardiac muscle, or myocardium, is deprived of blood. Therefore, the lack of oxygen destroys cardiomyocytes, leaving dead tissue and possib...

  5. Toxicology of Nanomaterials: Permanent interactive learning

    OpenAIRE

    Castranova Vince; Borm Paul

    2009-01-01

    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 is...

  6. Systemic Absorption of Nanomaterials by Oral Exposure

    DEFF Research Database (Denmark)

    Binderup, Mona-Lise; Bredsdorff, Lea; Beltoft, Vibe Meister;

    This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches.......This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches....

  7. Computational modeling of nanomaterials for biomedical applications

    OpenAIRE

    Verkhovtsev, Alexey

    2016-01-01

    Nanomaterials, i.e., materials that are manufactured at a very small spatial scale, can possess unique physical and chemical properties and exhibit novel characteristics as compared to the same material without nanoscale features. The reduction of size down to the nanometer scale leads to the abundance of potential applications in different fields of technology. For instance, tailoring the physicochemical properties of nanomaterials for modification of their interaction with a biological envi...

  8. An efficient analysis of nanomaterial cytotoxicity based on bioimpedance

    Energy Technology Data Exchange (ETDEWEB)

    Kandasamy, Karthikeyan; Kim, Sanghyo [College of Bionanotechnology, Kyungwon University, Gyeonggi-do (Korea, Republic of); Choi, Cheol Soo, E-mail: samkim@kyungwon.ac.kr [Lee Gil Ya Diabetes and Cancer Institute, Gachon University of Medicine and Science, Incheon (Korea, Republic of)

    2010-09-17

    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.

  9. 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.

  10. [Safety assessment of nanomaterials in reproductive developmental field].

    Science.gov (United States)

    Yamashita, Kohei; Yoshioka, Yasuo

    2012-01-01

    A diverse array of nanomaterials (NMs) such as amorphous nanosilica and carbon nanotubes have become widespread in use due to the development of nanotechnology. NMs are already being applied in universal fields because they have unique physicochemical properties. On the other hand, the increasing use of NMs has raised public concern about their potential risks to human health. In particular, recent reports indicated that carbon nanotubes induced mesothelioma-like lesions in mice, in a way similar to those induced by crocidolite asbestos. However, current knowledge of the potential risk of nanomaterials is considered insufficient. Because NMs have the potential to improve the quality of human life, it is essential to ensure the safety of NMs and provide information for designing NMs with safety. Especially, few studies have examined the effect of NMs on maintenance of pregnancy. Similar to the cases of thalidomide, a lot of evidence shows that fetuses are affected more than adults by a variety of environmental toxins because of physiological immaturity. Therefore it is essential to examine the effect of NMs on fetuses and pregnancies. Here we introduce the potential risk of amorphous nanosilica, most widely used NMs in food and the cosmetics field, to induce fetotoxicity and useful information for developing NMs with safety.

  11. An efficient analysis of nanomaterial cytotoxicity based on bioimpedance

    International Nuclear Information System (INIS)

    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.

  12. An efficient analysis of nanomaterial cytotoxicity based on bioimpedance

    Science.gov (United States)

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

    2010-09-01

    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.

  13. Screen-Printed Resistive Pressure Sensors Containing Graphene Nanoplatelets and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Daniel Janczak

    2014-09-01

    Full Text Available Polymer composites with nanomaterials such as graphene nanoplatelets and carbon nanotubes are a new group of materials with high application possibilities in printed and flexible electronics. In this study such carbon nanomaterials were used as a conductive phase in polymer composites. Pastes with dispersed nanomaterials in PMMA and PVDF vehicles were screen printed on flexible substrates, and used as an active layer in pressure sensors, exploiting contact resistance phenomena. The relationship between resistance and pressure is nearly linear on a logarithmic scale for selected types of samples, and their response is several times higher than for similar sensors with graphite layers. The use of surfactants allowed us to fabricate evenly dispersed nanomaterials with different amount of nanoplatelets and nanotubes in the composites. The samples contained from 1.25 wt.% to 2 wt.% of graphene and 1 wt.% to 0.5 wt.% of nanotubes and exhibited diverse sheet resistivity. Experiments revealed the relationship between morphology and loading of functional phase in the polymer matrix and the sensors’ sensitivity.

  14. Rational design of nanomaterials for water treatment

    Science.gov (United States)

    Li, Renyuan; Zhang, Lianbin; Wang, Peng

    2015-10-01

    The ever-increasing human demand for safe and clean water is gradually pushing conventional water treatment technologies to their limits. It is now a popular perception that the solutions to the existing and future water challenges will hinge upon further developments in nanomaterial sciences. The concept of rational design emphasizes on `design-for-purpose' and it necessitates a scientifically clear problem definition to initiate the nanomaterial design. The field of rational design of nanomaterials for water treatment has experienced a significant growth in the past decade and is poised to make its contribution in creating advanced next-generation water treatment technologies in the years to come. Within the water treatment context, this review offers a comprehensive and in-depth overview of the latest progress in rational design, synthesis and applications of nanomaterials in adsorption, chemical oxidation and reduction reactions, membrane-based separation, oil-water separation, and synergistic multifunctional all-in-one nanomaterials/nanodevices. Special attention is paid to the chemical concepts related to nanomaterial design throughout the review.

  15. Rational design of nanomaterials for water treatment

    KAUST Repository

    Li, Renyuan

    2015-08-26

    The ever-increasing human demand for safe and clean water is gradually pushing conventional water treatment technologies to their limits and it is now a popular perception that the solutions to the existing and future water challenges will highly hinge upon the further development of nanomaterial sciences. The concept of rational design emphasizes ‘design-for-purpose’ and it necessitates a scientifically clear problem definition to initiate the nanomaterial design. The field of rational design of nanomaterials for water treatment has experienced a significant growth in the past decade and is poised to make its contribution in creating advanced next-generation water treatment technologies in the years to come. Within the water treatment context, this review offers a comprehensive and in-depth overview of the latest progress of the rational design, synthesis and applications of nanomaterials in adsorption, chemical oxidation and reduction reactions, membrane-based separation, oil/water separation, and synergistic multifunctional all-in-one nanomaterials/nanodevices. Special attention is paid on chemical concepts of the nanomaterial designs throughout the review.

  16. A comparison between thermal-optical transmittance elemental carbon measured by different protocols in PM2.5 samples.

    Science.gov (United States)

    Giannoni, Martina; Calzolai, Giulia; Chiari, Massimo; Cincinelli, Alessandra; Lucarelli, Franco; Martellini, Tania; Nava, Silvia

    2016-11-15

    Although controlled procedures for the determination of carbonaceous fractions are of importance for any air quality measurements, currently no reference method for elemental carbon (EC) and organic carbon (OC) analysis is established yet in Europe. The implementation of the different thermal evolution protocols available in the literature, differing in temperature and duration of the heating ramps, affects the results and can result in a wide variation of EC and OC values. In this study three different protocols for thermal-optical-transmittance analysis of EC and OC were compared, namely He-870 (a variation of the NIOSH protocol), He-550 (a proxy of the IMPROVE protocol), and EUSAAR_2. Measurements were carried out on PM2.5 samples collected on Quartz fibre filters in three sites of different typology: urban background and urban traffic in Florence (Italy) and regional background in Livorno (Italy). The samples were analysed before and after a washing procedure to remove possible water-soluble organic compounds (WSOC), which may enhance the charring process, complicating the EC quantification. This study evidenced a very good agreement for TC measurement (at 2-3% level) and some discrepancies in EC measurement (up to 40%), as expected. WSOC and Pyrolitic Carbon (PyC) present a good correlation, independently of site typology, demonstrating that water soluble compound can be responsible of charring mechanism during the He phase.

  17. Evaluation of Quantitative Exposure Assessment Method for Nanomaterials in Mixed Dust Environments: Application in Tire Manufacturing Facilities.

    Science.gov (United States)

    Kreider, Marisa L; Cyrs, William D; Tosiano, Melissa A; Panko, Julie M

    2015-11-01

    Current recommendations for nanomaterial-specific exposure assessment require adaptation in order to be applied to complicated manufacturing settings, where a variety of particle types may contribute to the potential exposure. The purpose of this work was to evaluate a method that would allow for exposure assessment of nanostructured materials by chemical composition and size in a mixed dust setting, using carbon black (CB) and amorphous silica (AS) from tire manufacturing as an example. This method combined air sampling with a low pressure cascade impactor with analysis of elemental composition by size to quantitatively assess potential exposures in the workplace. This method was first pilot-tested in one tire manufacturing facility; air samples were collected with a Dekati Low Pressure Impactor (DLPI) during mixing where either CB or AS were used as the primary filler. Air samples were analyzed via scanning transmission electron microscopy (STEM) coupled with energy dispersive spectroscopy (EDS) to identify what fraction of particles were CB, AS, or 'other'. From this pilot study, it was determined that ~95% of all nanoscale particles were identified as CB or AS. Subsequent samples were collected with the Dekati Electrical Low Pressure Impactor (ELPI) at two tire manufacturing facilities and analyzed using the same methodology to quantify exposure to these materials. This analysis confirmed that CB and AS were the predominant nanoscale particle types in the mixing area at both facilities. Air concentrations of CB and AS ranged from ~8900 to 77600 and 400 to 22200 particles cm(-3), respectively. This method offers the potential to provide quantitative estimates of worker exposure to nanoparticles of specific materials in a mixed dust environment. With pending development of occupational exposure limits for nanomaterials, this methodology will allow occupational health and safety practitioners to estimate worker exposures to specific materials, even in scenarios

  18. Health implications of engineered nanomaterials

    Science.gov (United States)

    Pietroiusti, Antonio

    2012-02-01

    With the development of nanotechnology, a growing number of people are expected to be exposed to its products, the engineered nanomaterials (ENMs). Some physico-chemical properties of ENMs, linked to their size in the nanoscale (1-100 nm), make them potentially more reactive, and therefore raise concern about possible adverse effects in humans. In this article, I discuss human diseases which may be predicted after exposure to ENMs, and how their pathogenetic mechanisms may be linked to exposure; in this regard, special emphasis has been given to the triad of oxidative stress/inflammation/genotoxicity and to the interaction of ENMs/proteins in different biological compartments. The analysis of possible adverse effects has been made on an organ-by-organ basis, starting from the skin, respiratory system and gastrointestinal tract. These sites are in fact not only those exposed to the highest amounts of ENMs, but are also the portals of entry to internal organs for possible systemic effects. Although the list and the relevance of possible human disorders linked to ENM exposure are at least as impressive as that of their direct or indirect beneficial effects for human health, we must be clear that ENM-linked diseases belong to the realm of possible risk (i.e. cannot be excluded, but are unlikely), whereas ENMs with proven beneficial effects are on the market. Therefore, the mandatory awareness about possible adverse effects of ENMs should in no way be interpreted as a motivation to disregard the great opportunity represented by nanotechnology.

  19. Signal Amplification of Bioassay Using Zinc Nanomaterials

    Science.gov (United States)

    Cowles, Chad L.

    An emerging trend in the analytical detection sciences is the employment of nanomaterials for bioassay signal transduction to identify analytes critical to public health. These nanomaterials have been specifically investigated for applications which require identification of trace levels of cells, proteins, or other molecules that can have broad ranging impacts to human health in fields such as clinical diagnostics, environmental monitoring, food and drink control, and the prevention of bioterrorism. Oftentimes these nanoparticle-based signal transduction or amplification approaches offer distinct advantages over conventional methods such as increased sensitivity, rapidity, or stability. The biological application of nanoparticles however, does suffer from drawbacks that have limited more widespread adoption of these techniques. Some of these drawbacks are, high cost and toxicity, arduous synthesis methods, functionalization and bioconjugation challenges, and laboratory disposal and environmental hazard issues, all of which have impeded the progression of this technology in some way or another. This work aims at developing novel techniques that offer solutions to a number of these hurdles through the development of new nanoparticle-based signal transduction approaches and the description of a previously undescribed nanomaterial. Zinc-based nanomaterials offer the opportunity to overcome some of the limitations that are encountered when other nanomaterials are employed for bioassay signal transduction. On the other hand, the biological application of zinc nanomaterials has been difficult because in general their fluorescence is in the blue range and the reported quantum yields are usually too low for highly sensitive applications. The advantages of using zinc nanomaterials for biological applications, such as reduced toxicity, simple synthesis, low cost, and straightforward functionalization strategies contribute to the research interest in their application as

  20. Hybrid upconversion nanomaterials for optogenetic neuronal control

    Science.gov (United States)

    Shah, Shreyas; Liu, Jing-Jing; Pasquale, Nicholas; Lai, Jinping; McGowan, Heather; Pang, Zhiping P.; Lee, Ki-Bum

    2015-10-01

    Nanotechnology-based approaches offer the chemical control required to develop precision tools suitable for applications in neuroscience. We report a novel approach employing hybrid upconversion nanomaterials, combined with the photoresponsive ion channel channelrhodopsin-2 (ChR2), to achieve near-infrared light (NIR)-mediated optogenetic control of neuronal activity. Current optogenetic methodologies rely on using visible light (e.g. 470 nm blue light), which tends to exhibit high scattering and low tissue penetration, to activate ChR2. In contrast, our approach enables the use of 980 nm NIR light, which addresses the short-comings of visible light as an excitation source. This was facilitated by embedding upconversion nanomaterials, which can convert NIR light to blue luminescence, into polymeric scaffolds. These hybrid nanomaterial scaffolds allowed for NIR-mediated neuronal stimulation, with comparable efficiency as that of 470 nm blue light. Our platform was optimized for NIR-mediated optogenetic control by balancing multiple physicochemical properties of the nanomaterial (e.g. size, morphology, structure, emission spectra, concentration), thus providing an early demonstration of rationally-designing nanomaterial-based strategies for advanced neural applications.Nanotechnology-based approaches offer the chemical control required to develop precision tools suitable for applications in neuroscience. We report a novel approach employing hybrid upconversion nanomaterials, combined with the photoresponsive ion channel channelrhodopsin-2 (ChR2), to achieve near-infrared light (NIR)-mediated optogenetic control of neuronal activity. Current optogenetic methodologies rely on using visible light (e.g. 470 nm blue light), which tends to exhibit high scattering and low tissue penetration, to activate ChR2. In contrast, our approach enables the use of 980 nm NIR light, which addresses the short-comings of visible light as an excitation source. This was facilitated by

  1. Glutathione modified screen-printed carbon nanofiber electrode for the voltammetric determination of metal ions in natural samples.

    Science.gov (United States)

    Pérez-Ràfols, Clara; Serrano, Núria; Díaz-Cruz, José Manuel; Ariño, Cristina; Esteban, Miquel

    2016-08-01

    This work reports the development of a glutathione modified electrode via electrografting on a screen-printed carbon nanofiber substrate (GSH-SPCNFE). GSH-SPCNFE was compared to a classical screen-printed carbon electrode modified with glutathione (GSH-SPCE) for the simultaneous voltammetric determination of Cd(II) and Pb(II). Their electrochemical characterization and analytical performance suggest that SPCNFE could be a much better support for GSH immobilization. The applicability of GSH-SPCNFE for the determination of low concentration levels of Pb(II) and Cd(II) ions in environmental samples was successfully tested in a certified wastewater reference material by means of stripping voltammetry with a very high reproducibility and good trueness. PMID:27216650

  2. Validation of ten-minute single sample carbon-14 urea breath test for diagnosis of Helicobacter pylori infection

    Energy Technology Data Exchange (ETDEWEB)

    Prabakaran, K.; Fernandes, V.; McDonald, J. [Illawarra Regional Hospital, Wollongong, NSW (Australia). Depts of Nuclear Medicine and Gastroenterology

    1996-09-01

    Helicobacter pylori infection is traditionally diagnosed by endoscopy followed by gastric biopsy and histologic demonstration of organisms, rapid urease test and culture. The non-invasive carbon-14-urea breath test has been widely accepted now for the diagnosis of this bacterium. This study was aimed to establish and validate normal and abnormal values for an Australian population, for a single sample carbon-14-urea breath test at ten minutes. A dose of 185 kBq was used in order to achieve reasonable counting statistics. The derived values were validated with the results of the rapid urease test. This method has a high sensitivity, specificity and greater patient acceptance, and could be used in many clinical settings as the first modality for the diagnosis of H. pylori infection and for documenting response or cure after antibiotic therapy for eradication. 11 refs., 1 tab., 4 figs.

  3. Validation of ten-minute single sample carbon-14 urea breath test for diagnosis of Helicobacter pylori infection

    International Nuclear Information System (INIS)

    Helicobacter pylori infection is traditionally diagnosed by endoscopy followed by gastric biopsy and histologic demonstration of organisms, rapid urease test and culture. The non-invasive carbon-14-urea breath test has been widely accepted now for the diagnosis of this bacterium. This study was aimed to establish and validate normal and abnormal values for an Australian population, for a single sample carbon-14-urea breath test at ten minutes. A dose of 185 kBq was used in order to achieve reasonable counting statistics. The derived values were validated with the results of the rapid urease test. This method has a high sensitivity, specificity and greater patient acceptance, and could be used in many clinical settings as the first modality for the diagnosis of H. pylori infection and for documenting response or cure after antibiotic therapy for eradication. 11 refs., 1 tab., 4 figs

  4. Impairments of cells and genomic DNA by environmentally transformed engineered nanomaterials

    Science.gov (United States)

    Jones, Philip; Sugino, Sakiko; Yamamura, Shohei; Lacy, Fred; Biju, Vasudevanpillai

    2013-09-01

    Enormous increase in the production of nanomaterials and their growing applications in the device technology, biotechnology and biomedical areas suggest the need for developing models for predicting the environmental health and safety (EHS) risks posed by such nanomaterials. We hypothesize that CdSe quantum dots (QDs) and ZnO nanoparticles (NPs) encompassed in liposomes or not and transformed by simulated solar UV light can be model systems for studying the environmental toxicity of engineered nanomaterials. In this study, human lung epithelial adenocarcinoma cells (H1650) are exposed to photoirradiated CdSe QDs or ZnO nanopowder included or not in liposomes. The release of cadmium and zinc ions from the nanomaterials exposed to solar simulated UV radiation is detected and quantified by measuring the steady-state and time resolved fluorescence of the metal ion sensor tetracarboxyphenylporphyrin (TCPP) or the commercial Measure iT Pd/Cd sensor. Viability of cells treated with nanomaterials exposed to solar simulated UV radiation for different durations is measured by MTT assay. Enhanced etching of the nanoparticles exposed to solar simulated UV radiation results in the release of toxic levels of heavy metal ions, which considerably lower the viability of H1650 cells is due to the deactivation of DNA repair enzymes as evidenced by the pinching off of nuclear DNA in comet assays and DNA samples in electrophoresis. Results from this study highlight the need to obtain not only quantitative information about the environmental risks posed by engineered nanomaterials but also environment friendly nanomaterials for practical applications.Enormous increase in the production of nanomaterials and their growing applications in the device technology, biotechnology and biomedical areas suggest the need for developing models for predicting the environmental health and safety (EHS) risks posed by such nanomaterials. We hypothesize that CdSe quantum dots (QDs) and ZnO nanoparticles

  5. Sensors for breath testing: from nanomaterials to comprehensive disease detection.

    Science.gov (United States)

    Konvalina, Gady; Haick, Hossam

    2014-01-21

    The analysis of volatile organic compounds in exhaled breath samples represents a new frontier in medical diagnostics because it is a noninvasive and potentially inexpensive way to detect illnesses. Clinical trials with spectrometry and spectroscopy techniques, the standard volatile-compound detection methods, have shown the potential for diagnosing illnesses including cancer, multiple sclerosis, Parkinson's disease, tuberculosis, diabetes, and more via breath tests. Unfortunately, this approach requires expensive equipment and high levels of expertise to operate the necessary instruments, and the tests must be done quickly and use preconcentration techniques, all of which impede its adoption. Sensing matrices based on nanomaterials are likely to become a clinical and laboratory diagnostic tool because they are significantly smaller, easier-to-use, and less expensive than spectrometry or spectroscopy. An ideal nanomaterial-based sensor for breath testing should be sensitive at very low concentrations of volatile organic compounds, even in the presence of environmental or physiological confounding factors. It should also respond rapidly and proportionately to small changes in concentration and provide a consistent output that is specific to a given volatile organic compound. When not in contact with the volatile organic compounds, the sensor should quickly return to its baseline state or be simple and inexpensive enough to be disposable. Several reviews have focused on the methodological, biochemical, and clinical aspects of breath analysis in attempts to bring breath testing closer to practice for comprehensive disease detection. This Account pays particular attention to the technological gaps and confounding factors that impede nanomaterial-sensor-based breath testing, in the hope of directing future research and development efforts towards the best possible approaches to overcome these obstacles. We discuss breath testing as a complex process involving numerous

  6. Mechanical Behaviour and Microstructural Characterization of Carbon Steel Samples from Three Selected Steel Rolling Plants

    OpenAIRE

    P. O. Atanda; Abioye, A. A.; A. O. Iyiola

    2015-01-01

    The research investigated the mechanical behavior of samples of steel rods obtained from three selected Steel Rolling Companies in South Western part of Nigeria. This was done by carrying out some mechanical tests such as tensile, impact and hardness as well as microstructural examination.Four sets of 16 mm steel rod samples were collected from Tiger steel industries, Phoenix steel and Oxil steel Industies, all located in South West Nigeria, The chemical composition was carried out using a...

  7. Fast microextraction of phthalate acid esters from beverage, environmental water and perfume samples by magnetic multi-walled carbon nanotubes.

    Science.gov (United States)

    Luo, Yan-Bo; Yu, Qiong-Wei; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-02-15

    In this work, magnetic carbon nanotubes (CNTs) were prepared by mixing the magnetic particles and multi-walled carbon nanotubes dispersed solutions. Due to their excellent adsorption capability towards hydrophobic compounds, the magnetic CNTs were used as adsorbent of magnetic solid-phase extraction (MSPE) to extract phthalate acid esters (PAEs), which are widely used in many consumable products with potential carcinogenic properties. By coupling MSPE with gas chromatography/mass spectrometry (GC/MS), a rapid, sensitive and cost-effective method for the analysis of PAEs was established. Our results showed that the limits of detection (LODs) of 16 PAEs ranged from 4.9 to 38 ng L(-1), which are much lower compared to the previously reported methods. And good linearities of the detection method were obtained with correlation coefficients (R(2)) between 0.9821 and 0.9993. In addition, a satisfying reproducibility was achieved by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) less than 11.7% and 14.6%, respectively. Finally, the established MSPE-GC/MS method was successfully applied to the determination of PAEs from bottled beverages, tap water and perfume samples. The recoveries of the 16 PAEs from the real samples ranged from 64.6% to 125.6% with the RSDs less than 16.5%. Taken together, the MSPE-GC/MS method developed in current study provides a new option for the detection of PAEs from real samples with complex matrices.

  8. Investigation into the enhancement of polycarbonate with conductive nanomaterials

    Science.gov (United States)

    Via, Michael D., Jr.

    Polymers are typically electrically and thermally insulating materials. The electrical and thermal conductivities of polymers can be increased by the addition conductive fillers such as carbons. Once the polymer composites have been made electrically and thermally conductive, they can be used in applications where these conductivities are desired such as electromagnetic shielding and static dissipation. In this project, three carbon nanomaterials are added to polycarbonate to enhance the electrical and thermal conductivity of the resulting composite. Hyperion Catalysis FIBRILs carbon nanotubes were added to a maximum loading of 8 wt%. Ketjenblack EC-600 JD carbon black was added to a maximum loading of 10 wt%. XG Sciences xGnP(TM) graphene nanoplatelets were added to a maximum loading of 15 wt%. These three materials have drastically different morphologies and will have varying effects on the various properties of polycarbonate composites. It was determined that carbon nanotubes have the largest effect on electrical conductivity with an 8 wt% carbon nanotube in polycarbonate composite having an electrical conductivity of 0.128 S/cm (from a pure polycarbonate value of 10-17 S/cm). Carbon black has the next largest effect with an 8 wt% carbon black in polycarbonate composite having an electrical conductivity of 0.008 S/cm. Graphene nanoplatelets have the least effect with an 8 wt% graphene nanoplatelet in polycarbonate having an electrical conductivity of 2.53 x 10-8 S/cm. Graphene nanoplatelets show a significantly higher effect on increasing thermal conductivity than either carbon nanotubes or carbon black. Mechanically, all three materials have similar effects with graphene nanoplatelets being somewhat more effective at increasing the tensile modulus of the composite than the other fillers. Carbon black and graphene nanoplatelets show standard carbon-filler rheology where the addition of filler increases the viscosity of the resulting composite. Carbon nanotubes

  9. Environmental implications and applications of nanomaterials

    Science.gov (United States)

    Bhattacharya, Priyanka

    Recent advances in material science and nanotechnology have given rise to a myriad of developments, while in the meantime call for research into the impacts of nanomaterials on the environment and human health. Although considerable progress has been made in the past decade concerning the behavior of nanomaterials in biological systems, such understanding is critically lacking with respect to the fate of nanomaterials in ecosystems. Accordingly, this dissertation addresses the interactions between nanomaterials and algae---the major constituent of the aquatic food chain (Part I, Chapter two), and exploits the physicochemistry of nanoscaled synthetic dendritic polymers for environmental applications, especially for water purification that is a focused theme of the entire dossier (Part II, Chapters two--five). This dissertation is organized as follows. Chapter one presents a general review of the physical/physicochemical properties, characterizations, implications---especially ecological implication, and applications of a host of most produced and studied nanomaterials. In addition, advances in environmental applications of nanomaterials are discussed. Chapter two examines algal responses to two major types of engineered nanomaterials---quantum dots and polystyrene. Inhibited photosynthetic activities of green algae are observed as a result of the physical adsorption of the nanomaterials. Chapter three elucidates the physicochemical properties of poly(amidoamine)-tris(hydroxymethyl)amidomethane- and amine-terminated dendrimers towards their applications in water remediation. Here, the capacities and mechanisms of the dendrimers in hosting cationic copper, anionic nitrate, polyaromatic phenanthrene, and the more heterogeneous humic acids are discussed. Based on the results of Chapter three, Chapter four presents a dendrimer-based novel optical scheme for improving the detection sensitivity and selectivity of environmental pollutants. Specifically, the surface plasmon

  10. The Inventory of Forest Carbon Stocks in the Province of Trento: some remarks on the sampling design and first comments on its results

    OpenAIRE

    Gasparini P; Tabacchi G

    2008-01-01

    Multiple sampling designs are commonly used in forest inventory to combine information collected in very large first-phase samples using remote sensing (satelite or aerial images) with the field data collected on smaller sub-samples. In Italy, during the seventies, double sampling designs were used in some regional forest inventories and, later, multiple sampling was adopted for the second National Forest Inventory and for the Inventory of Forest Carbon Stocks (InFoCarb) in the Province of Tr...

  11. Methodological considerations of electron spin resonance spin trapping techniques for measuring reactive oxygen species generated from metal oxide nanomaterials

    Science.gov (United States)

    Jeong, Min Sook; Yu, Kyeong-Nam; Chung, Hyun Hoon; Park, Soo Jin; Lee, Ah Young; Song, Mi Ryoung; Cho, Myung-Haing; Kim, Jun Sung

    2016-05-01

    Qualitative and quantitative analyses of reactive oxygen species (ROS) generated on the surfaces of nanomaterials are important for understanding their toxicity and toxic mechanisms, which are in turn beneficial for manufacturing more biocompatible nanomaterials in many industrial fields. Electron spin resonance (ESR) is a useful tool for detecting ROS formation. However, using this technique without first considering the physicochemical properties of nanomaterials and proper conditions of the spin trapping agent (such as incubation time) may lead to misinterpretation of the resulting data. In this report, we suggest methodological considerations for ESR as pertains to magnetism, sample preparation and proper incubation time with spin trapping agents. Based on our results, each spin trapping agent should be given the proper incubation time. For nanomaterials having magnetic properties, it is useful to remove these nanomaterials via centrifugation after reacting with spin trapping agents. Sonication for the purpose of sample dispersion and sample light exposure should be controlled during ESR in order to enhance the obtained ROS signal. This report will allow researchers to better design ESR spin trapping applications involving nanomaterials.

  12. Measurement techniques for carbon dioxide sorption capacity on various coal samples: critical review

    Science.gov (United States)

    Abunowara, M.; Bustam, M. A.; Sufian, S.; Eldemerdash, U.

    2016-06-01

    Underground carbon sequestration is proposed as a geologic disposal technique for the long-term storage of CO2 emissions to mitigate climate change and air pollution. Coal bed seams have large CO2 adsorption capacity, long time CO2 trapping and extra enhanced coal-bed methane recovery (CBM). However, CO2 sorption capacity is one of significant steps required to be determined accurately in any feasibility evaluation of carbon sequestration. Hence, in lab scale, there are three methods for CO2 adsorption capacity measurements namely manometric/volumetric, gravimetric and new capsule techniques for gas sorption on variety of sorbents. The manometric and volumetric methods require accurate determination of cell and void volumes and suitable equation of state (EoS). The gravimetric method requires a very accurate sensitive balance and less buoyancy effect and it is the best technique for small amounts (milligrams) of sorbents and the adsorption equilibrium can be mentored. Among all gas adsorption measurement techniques, the newly developed method “capsule method” exhibits the highest CO2 adsorption capacity on Polish coal by 4.08 mmol/g because capsule method that directly measures CO2 uptake of solid coal matrix cylinders, without the application of the equation of state (EoS) for CO2 or volumetric corrections. The main advantage of capsule method is that it is independent of any Equation of State (EoS), and it has no volumetric effects or impurities distort the shape of the gas adsorption isotherm. The disadvantage of capsule method is time-consuming and it is not easy to implement.

  13. A review of analytical techniques for the determination of carbon-14 in environmental samples

    International Nuclear Information System (INIS)

    This report contains a brief summary of analytical techniques commonly used for the determination of radiocarbon in a variety of environmental samples. Details of the applicable procedures developed and tested in the Environmental Research Branch at Chalk River Laboratories are appended

  14. A review of the antibacterial effects of silver nanomaterials and potential implications for human health and the environment

    International Nuclear Information System (INIS)

    Here, we present a review of the antibacterial effects of silver nanomaterials, including proposed antibacterial mechanisms and possible toxicity to higher organisms. For purpose of this review, silver nanomaterials include silver nanoparticles, stabilized silver salts, silver-dendrimer, polymer and metal oxide composites, and silver-impregnated zeolite and activated carbon materials. While there is some evidence that silver nanoparticles can directly damage bacteria cell membranes, silver nanomaterials appear to exert bacteriocidal activity predominantly through release of silver ions followed (individually or in combination) by increased membrane permeability, loss of the proton motive force, inducing de-energization of the cells and efflux of phosphate, leakage of cellular content, and disruption DNA replication. Eukaryotic cells could be similarly impacted by most of these mechanisms and, indeed, a small but growing body of literature supports this concern. Most antimicrobial studies are performed in simple aquatic media or cell culture media without proper characterization of silver nanomaterial stability (aggregation, dissolution, and re-precipitation). Silver nanoparticle stability is governed by particle size, shape, and capping agents as well as solution pH, ionic strength, specific ions and ligands, and organic macromolecules-all of which influence silver nanoparticle stability and bioavailability. Although none of the studies reviewed definitively proved any immediate impacts to human health or the environment by a silver nanomaterial containing product, the entirety of the science reviewed suggests some caution and further research are warranted given the already widespread and rapidly growing use of silver nanomaterials.

  15. Study of the nanomaterials and their antimicrobial activities

    Science.gov (United States)

    Ramadi, Muntaha

    In the last decade, the world faced huge problems associated with the spread of antimicrobial resistant infections that are essentially untreatable such as methicillin resistant Staphylococcus aureus (MRSA) infection. These infections have begun to occur in both hospital and community environments. Developing new antimicrobial surface coatings can hold a great promise to minimize and control various problems that associated with the spreading of infections and biofilms formation, these coatings can be used in medicine where medical devices associated with severe infections, in construction industry and the in food packaging industry. It has been established that single-walled CNTs exhibit a strong antimicrobial activity and can pierce bacterial cell walls. Recently, nanomaterial structures that made from pure carbon such as CNTs have been seen as promising candidates for many potential applications in Biotechnology and bioscience due to the combination of their extraordinary properties that arise from surface area, light weight, strength, flexibility, unique electrical conductivity and many more novel physical and chemical properties at nanoscale level. CNTs have been used widely in biomedical field including drug delivery, gene therapy and creating new biomedical devices with novel properties. Researchers have now made a first step to add carbon nanotubes to antimicrobial agents list. There are two types of CNTs have been used in biomedical research. The first one is a single-walled carbon nanotube (SWNT) and the second is a multi-walled carbon nanotube (MWNT). Recent in vitro studies suggest that carbon nanotubes have antimicrobial activity and coating CNTs with nickel nanoparticle could enhance the antimicrobial activity of cabon nanotubes. In order to test this hypothesis, nickel nanoparticles were deposited on carbon nanotubes (CNTs) by electrochemical deposition. The carbon nanotubes used in this study were XD-CNTs, SWNTs and Ni-coated CNTs. The structure and

  16. Nanomaterials Applied in Asphalt Modification: A Review

    Institute of Scientific and Technical Information of China (English)

    Changqing Fang; Ruien Yu; Shaolong Liu; Yan Li

    2013-01-01

    Nanotechnology has been gradually penetrated into the field of asphalt modification.Seemingly magic effects of nanomaterials have now been brought to improve the performance of asphalt.To demonstrate many of the prospective applications,researchers have conducted a series of positive and effective efforts dealing with the preparation of modified asphalt to demonstrate the mechanism of modification and the resultant improvement in performance.In this review,various nanomaterials used in asphalt modification are initially presented,followed by the methods employed to modify the asphalt with these materials and finally the effects of nanomaterials on the performance of base asphalt are presented and the modification mechanisms are discussed.Based on the current research results,the influence of preparation process parameters on the compatibility of every phase in the modified asphalt and the stability of the modified asphalt system are described.Finally,the development trend of the topic field is projected.

  17. Production of nanomaterials: physical and chemical technologies

    International Nuclear Information System (INIS)

    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.

  18. Applicability of Different Isothermal EOS at Nanomaterials

    Directory of Open Access Journals (Sweden)

    Deepika P. Joshi

    2013-01-01

    Full Text Available The present study explains the behaviour of nanomaterials such as AlN, CdSe, Ge, WC, and Ni- and Fe-filled-MWCNTs under high pressure. Among the number of isothermal EOSs available, we prefer only two parameter-based isothermal equations (i.e., Murnaghan equation, usual Tait's equation, Suzuki equation and Shanker equation. The present work shows the theoretical study of thermo-elastic properties especially relative compression (V/V0, isothermal bulk modulus (KP/K0, and compressibility (αP/α0 of nanomaterials. After comparing all formulations with available experimental data, we conclude that pressure dependence of relative compression (V/V0 for the nanomaterials, are in good agreement for all the equations at lower pressure range. At higher pressure range, Suzuki and Shanker formulations show some deviation from experimental values.

  19. Synthesis of camptothecin-loaded gold nanomaterials

    International Nuclear Information System (INIS)

    Camptothecin-loaded gold nanomaterials have been synthesized by the sodium borohydride reduction method under a strong basic condition. The obtained gold nanomaterials have been characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-vis absorption spectroscopy. The camptothecin-loaded gold colloidal solution was very stable and can be stored for more than two months at room temperature without obvious changes. The color of the colloidal solution can change from wine red to purple and blue during the acidifying process. It was revealed that the release of camptothecin and the aggregation of gold nanoparticles can be controlled by tuning the solution pH. The present study implied that the gold nanomaterials can be used as the potential carrier for CPT delivery.

  20. Studies and Development of Radiation Processed Nanomaterials

    International Nuclear Information System (INIS)

    Nanotechnology is the emerging technology that deals with processing, manipulating and manufacturing devices and products at the microscopic scale of molecules or atoms with structures smaller than 100 nanometers. Realizing its potential, Government of India spending on R&D in nanotechnology has gone up by an order of magnitude in last 5 years through various national and international programs. High energy gamma radiation and electron beams could be a useful tool to create innovative and newer nano-materials for various applications in medical field for treatment and detection purposes. Considering its certain advantage for producing nano-materials, radiation technology will play a crucial role in development of such materials. Research and development in the area of nano--particles on polymer films, hydrogels, silica particles and their nano-clusters using radiation technology could be a possible route for development of new functional nano-materials. (author)