Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Gianluigi Zito,
• Teresa Cacace,
• Antigone Marino,
• José M. Otón and
• Morten A. Geday

Beilstein J. Nanotechnol. 2016, 7, 825–833, doi:10.3762/bjnano.7.74

• modifications in the electrical and electro-optical properties of liquid crystals. The control of the SWCNT concentration, distribution and reorientation in such self-organized fluids allows for the possibility of tuning the liquid crystal properties. The alignment and reorientation of CNTs are studied in a

• system where the liquid crystal orientation effect has been isolated. Complementary studies including Raman spectroscopy, microscopic inspection and impedance studies were carried out. The results reveal an ordered reorientation of the CNTs induced by an electric field, which does not alter the

• orientation of the liquid crystal molecules. Moreover, impedance spectroscopy suggests a nonnegligible anchoring force between the CNTs and the liquid crystal molecules. Keywords: Anchoring; carbon nanotubes; impedance; liquid crystal; negative anisotropy; Raman spectroscopy; reorientation; single-wall CNTs

Comparison of the interactions of daunorubicin in a free form and attached to single-walled carbon nanotubes with model lipid membranes

• Dorota Matyszewska

Beilstein J. Nanotechnol. 2016, 7, 524–532, doi:10.3762/bjnano.7.46

• -stranded DNA or RNA sequences showing high specificity and affinity to their targets, which were employed as molecular targeting agents for targeted drug transport. Carbon nanotubes (CNTs) are among the promising drug delivery systems. They attract scientists’ attention due to their properties such as

• mechanisms proposed to explain the cellular uptake of CNTs including the passive diffusion in a non-invasive manner (tiny nanoneedle mechanism) [18]. Carbon nanotubes have been successfully used to transport different types of anticancer agents including camptothecin, doxorubicin and daunorubicin [19]. The

• two main methods of attaching the drugs comprise either covalent attachment or physical adsorption based on π–π stacking interactions. There are a few reports in the literature on the preparation and characterization of CNTs-DNR adducts used as drug delivery systems. In those works daunorubicin was

Free vibration of functionally graded carbon-nanotube-reinforced composite plates with cutout

• Mostafa Mirzaei and
• Yaser Kiani

Beilstein J. Nanotechnol. 2016, 7, 511–523, doi:10.3762/bjnano.7.45

• -mechanical properties, carbon nanotubes (CNTs) have attracted increasing attention in the past decades. CNTs are a promising candidate for the reinforcement of the matrix phase in a composite. Kwon et al. [1] reported that using a powder metallurgy fabrication process, carbon-nanotube-reinforced composites

• (CNTRCs) may be achieved with a nonuniform distribution of CNTs through the media. This type of reinforced composite media is known as functionally graded carbon-nanotube-reinforced composite (FG-CNTRC). An overview on the properties, modeling and characteristics of FG-CNTRC beams, plates and shells is

• provided by Liew et al. [2] It has been shown that the bending moment may be significantly alleviated through a functionally graded distribution of CNTs in a polymeric matrix [3]. In the five years following the discovery of this interesting feature, various investigations were reported on the mechanics of

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• able to generate, store and transport electricity in a clean and more efficient way and with smaller space requirements. Specifically, the use of nanostructured allotrope forms of carbon and derivatives such as fullerenes, carbon nanotubes (CNTs) and graphene have been widely investigated over the past

• , thermal and electrical properties of the different allotrope forms are directly correlated to their structure and hybridization state, opening up the possibility to use the same material for a wide range of applications [19]. Herein, the synthesis and application of fullerenes, CNTs and graphene will be

• it with o-dichlorobenzene solution or with trifluoroacetic acid (Figure 8) [36]. Carbon nanotubes Carbon nanotubes (CNTs), discovered by Ijima in 1991 [37], are another allotrope form of carbon with a cylindrical structure. The unique structure of CNTs results in many extraordinary properties. Since

Application of biclustering of gene expression data and gene set enrichment analysis methods to identify potentially disease causing nanomaterials

• Andrew Williams and
• Sabina Halappanavar

Beilstein J. Nanotechnol. 2015, 6, 2438–2448, doi:10.3762/bjnano.6.252

• black (CB) or carbon nanotubes (CNTs) to determine the disease significance of these data-driven gene sets. Results: Biclusters representing inflammation (chemokine activity), DNA binding, cell cycle, apoptosis, reactive oxygen species (ROS) and fibrosis processes were identified. All of the NM studies

• fibrosis. The pro-fibrogenic potential of CNTs is well established. Although CB has not been shown to induce fibrosis, it induces stronger inflammatory, oxidative stress and DNA damage responses than nano-TiO2 particles. Conclusion: The results of the analysis correctly identified all NMs to be

• inflammogenic and only CB and CNTs as potentially fibrogenic. In addition to identifying several previously defined, functionally relevant gene sets, the present study also identified two novel genes sets: a gene set associated with pulmonary fibrosis and a gene set associated with ROS, underlining the

Plasma fluorination of vertically aligned carbon nanotubes: functionalization and thermal stability

• Claudia Struzzi,
• Mattia Scardamaglia,
• Axel Hemberg,
• Luca Petaccia,
• Jean-François Colomer,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 2263–2271, doi:10.3762/bjnano.6.232

• chamber, mainly as water vapor, is also grafted on the CNTs surface in addition to fluorine species leading to oxyfluorination of the vCNTs. The fluorine functionalization causes the hybridization change from sp2 to sp3 of the carbon atoms. We show that controlled thermal heating of the sample allows for

• displayed in Figure 4 confirm the impact of the plasma fluorination on the vibrational modes of the pristine sample. This technique is often used for a qualitative investigation of the functionalization effect on carbon nanotubes structures [2][44][45][46][47] and to quantify the defect density in the CNTs

NanoE-Tox: New and in-depth database concerning ecotoxicity of nanomaterials

• Katre Juganson,
• Angela Ivask,
• Irina Blinova,
• Monika Mortimer and
• Anne Kahru

Beilstein J. Nanotechnol. 2015, 6, 1788–1804, doi:10.3762/bjnano.6.183

• database NanoE-Tox that is available as Supporting Information File 2. The database is based on existing literature on ecotoxicology of eight ENMs with different chemical composition: carbon nanotubes (CNTs), fullerenes, silver (Ag), titanium dioxide (TiO2), zinc oxide (ZnO), cerium dioxide (CeO2), copper

• sensitive organism (data derived from three or more articles) the toxicity order was as follows: Ag > ZnO > CuO > CeO2 > CNTs > TiO2 > FeOx. We believe NanoE-Tox database contains valuable information for ENM environmental hazard estimation and development of models for predicting toxic potential of ENMs

• : carbon nanotubes (CNTs), fullerenes, silver (Ag), titanium dioxide (TiO2), zinc oxide (ZnO), cerium dioxide (CeO2), copper oxide (CuO), and iron oxide (FeOx; Fe2O3, Fe3O4). Furthermore, all these ENMs, except CuO, are listed by the Organisation for Economic Co-operation and Development (OECD) Working

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• nanoparticles were also essential ingredients in inks and printing pastes used over centuries in various cultures [17]. Another example are carbon nanotubes (CNTs) [18] which found their way into the secret recipe of ultra-sharp Damascus steel, which dates back to seventeenth century, and are believed to be

• dispersed into a colloidal solution. CNTs in Damascus steel are found to encapsulate cementite nanowires which might account for its super-plastic behavior. More recently, the report of graphene [22] has triggered extensive studies on its rich physics and has opened up wide applications in photoelectric

• al. commented that extended holes (rather than a knock-on vacancy) grow over a wide range from 20 to 100 keV, or even below 20 keV. A mechanism of beam-induced etching with residual water or oxygen in the system is therefore suggested [40]. The strong anisotropic tubular structure of CNTs leads to an

Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers

• Deborah Vidick,
• Xiaoxing Ke,
• Michel Devillers,
• Claude Poleunis,
• Arnaud Delcorte,
• Pietro Moggi,
• Gustaaf Van Tendeloo and
• Sophie Hermans

Beilstein J. Nanotechnol. 2015, 6, 1287–1297, doi:10.3762/bjnano.6.133

• explained by the elongated shape of the CNTs and CNFs. The molecular peak corresponding to the intact cluster was not observed. This could have been an indication of the fact that it is transformed by the anchoring process. However, both metals and some fragments are detected by SIMS at the surface, which

• (TEM) imaging is used to determine particle sizes after activation and to image their dispersion. TEM images of clusters 1 to 3 on MWNT–PPh2 (Figure 3a–c) reveal that nanoparticles with diameters of 1–3 nm are homogeneously dispersed on CNTs. Cluster 4 on MWNT–PPh2 (Figure 3f) or CNF–PPh2 (Figure 3d,e

Interaction of electromagnetic radiation in the 20–200 GHz frequency range with arrays of carbon nanotubes with ferromagnetic nanoparticles

• Agylych Atdayev,
• Alexander L. Danilyuk and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2015, 6, 1056–1064, doi:10.3762/bjnano.6.106

• nanocomposites are prospects for memory storage, emission and high frequency devices. New magnetic nanocomposites based on carbon nanotubes (CNTs) [1][2][3] are very promising for high frequency applications [4][5][6][7][8][9][10][11][12][13][14] such as transmission lines, mixtures and detectors [15][16][17

• catalytic iron-based nanoparticles (NPs). Under standard FCCVD conditions (i.e., synthesis temperature: 1150 K, ferrocene concentration: 5–10 wt %, injection rate of the Ar carrier gas: 100 cm3/min, growth duration: 1 min), the multiwall CNTs are formed. The height of the structure is approximately 50 μm

• ferrocene content are distributed both inside and outside the CNTs and are covered by a carbon shell which prevents their oxidation [8][32][33]. The average size of the NPs is slightly less than the CNT diameter, and lies in the range of a = 20–30 nm [34], and are therefore considered as a single domain [35

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

Simulation tool for assessing the release and environmental distribution of nanomaterials

• Haoyang Haven Liu,
• Muhammad Bilal,
• Anastasiya Lazareva,
• Arturo Keller and
• Yoram Cohen

Beilstein J. Nanotechnol. 2015, 6, 938–951, doi:10.3762/bjnano.6.97

• associated with coating, paint, and pigment applications (≈41%). Finally, the largest contributions to the release of CNTs into air, water and soil are associated with composites (≈28%), coatings, paints and pigments (≈43%), and energy and environmental applications (≈40%), respectively. The contributions of

Pt- and Pd-decorated MWCNTs for vapour and gas detection at room temperature

• Hamdi Baccar,
• Atef Thamri,
• Pierrick Clément,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2015, 6, 919–927, doi:10.3762/bjnano.6.95

• composition studies The morphology and composition of sputtered, metal-decorated CNTs were studied by transmission electron microscopy (TEM) and by X-ray photoelectron spectroscopy (XPS), respectively. For the TEM analysis, pristine MWCNTs were dropped onto a commercial, lacey-carbon grid. This was then

• electrons to pass easily between the metal nanoparticles and CNTs. The direction of the charge transfer depends on the composition of the surrounding gas. Furthermore, the electronegativity values for Pt and Pd are quite similar and so is the relative weight (in atom %) of the metal dopants in both types of

Applications of three-dimensional carbon nanotube networks

• Manuela Scarselli,
• Paola Castrucci,
• Francesco De Nicola,
• Ilaria Cacciotti,
• Francesca Nanni,
• Emanuela Gatto,
• Mariano Venanzi and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• supports [10], and super capacitors [11]. In this research field, architectures based on carbon nanotubes (CNTs) are the focus of intense research activity [2]. Since CNTs are one-dimensional structures with well-known electrical and mechanical properties, they are the ideal building blocks for

•  2, the statistical analysis gives a double distribution of the external diameter centered at 91 ± 3 nm, and 418 ± 5 nm, respectively. The length of the tubes can vary from few nanometers to millimeters, and the CNTs have a high number of walls as evidenced by a transmission electron microscopy

• studies described in [13]. SEM micrographs obtained at higher magnification evidence the presence of interconnected and curled CNTs as shown in Figure 2b. The electron energy loss spectroscopy analysis performed in reflection mode further supports the predominance of C-sp2 hybridization in the nanotubes

Observation of a photoinduced, resonant tunneling effect in a carbon nanotube–silicon heterojunction

• Carla Aramo,
• Antonio Ambrosio,
• Michelangelo Ambrosio,
• Maurizio Boscardin,
• Paola Castrucci,
• Michele Crivellari,
• Marco Cilmo,
• Maurizio De Crescenzi,
• Francesco De Nicola,
• Emanuele Fiandrini,
• Valentina Grossi,
• Pasqualino Maddalena,
• Maurizio Passacantando,
• Sandro Santucci,
• Manuela Scarselli and
• Antonio Valentini

Beilstein J. Nanotechnol. 2015, 6, 704–710, doi:10.3762/bjnano.6.71

• that are aligned only at a certain applied voltage. In the case of carbon nanotubes (CNTs), a number of cases have been reported in which this effect has been observed both for single-walled as well as for double-walled CNTs [3][4][5]. In this work, a photosensitive junction was fabricated which

• mechanisms behind the infrared sensitivity of CNTs have been discussed by various authors [9][10]. The photoconductivity of individual CNTs, as well as ropes and films of CNTs have been studied extensively both in the visible [11] and the infrared [12] range. The variations in the photoconductivity of CNT

• -based devices have been attributed to the photon-induced generation of charge carriers in single-wall CNTs and the subsequent charge separation across the carbon nanotube–metal contact interface [11]. To the best of our knowledge, there is a lack of measurements in the UV region [8], and moreover, there

Filling of carbon nanotubes and nanofibres

• Reece D. Gately and
• Marc in het Panhuis

Beilstein J. Nanotechnol. 2015, 6, 508–516, doi:10.3762/bjnano.6.53

• is still very much prevalent today. The main advantages of using CNTs to produce metallic nanowires is that the CNTs act as a template for self-assembly of the nanowires [40][41] and the CNT structure can act as a protective sheath to protect the nanowire from being damaged by chemicals in harsh

• conditions/environments [42]. CNTs have also been used as sacrificial templates. The CNTs can be removed by heat treating (generally requiring temperatures greater than 600 °C), thereby leaving the metal structures unaltered and exposed [43][44]. It has also been shown that the irradiation of a filled MWCNT

• recent review focussed on the use of CNTs filled with antitumour medication for use in chemotherapy and immunotherapy [49]. In particular, they noted that the high level of selectivity (when functionalized) gave the CNTs the ability to “seek out” and selectively deliver the contained drugs to the tumours

Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2015, 6, 396–403, doi:10.3762/bjnano.6.39

• carbon nanotubes (CNTs) and the possibility of reorienting them with external fields [3][4][5][6]. The interest to control this reorientation arises from the possibility of preparing simple devices whose electrical conductivity can be externally controlled and modulated [5][6][7][8][9]. Due to their

• outstanding physical properties, CNTs have attracted a great deal of interest during the past 25 years [3][4][5][6]. They are formed from one or several rolled-up graphene sheets. CNTs show peculiar electrical properties: In single-walled carbon nanotubes (SWCNT), the conductivity is either metallic or

• semiconductive, while in multi-walled CNTs (MWCNT) it is always metallic [10]. The almost one-dimensional structure leads to a long-range ballistic electron transport in metallic CNTs [10][11]. LCs are self-organized anisotropic fluids, whose long-range orientation (called director) can be induced by surface

Release behaviour and toxicity evaluation of levodopa from carboxylated single-walled carbon nanotubes

• Julia M. Tan,
• Jhi Biau Foo,
• Sharida Fakurazi and
• Mohd Zobir Hussein

Beilstein J. Nanotechnol. 2015, 6, 243–253, doi:10.3762/bjnano.6.23

• of the diseased cells. Generally, drug carriers can be categorized into four major groups: inorganic nanoparticles [2][3], recombinant proteins [4], viral or non-viral carriers [5] and organic cationic compounds [6]. Recently, inorganic nanoparticles such as carbon nanotubes (CNTs) were subjected to

• ultrahigh surface area can enhance the loading capacity of different macromolecules or bioactive compounds, which are chemically attached to their side walls, tips or encapsulated inside the tubes. In addition, sufficiently functionalized CNTs can also adequately reduce the cytotoxic side effects of CNTs

• , and at the same time, further enhance their degree of biocompatibility [7]. This is because non-functionalized CNTs tend to aggregate into bundles due to van der Waals interactions and hence, they might induce apoptosis (cell death) after administration into the human body. Parkinson’s disease (PD) or

Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

• Gemma Rius,
• Matteo Lorenzoni,
• Soichiro Matsui,
• Masaki Tanemura and
• Francesc Perez-Murano

Beilstein J. Nanotechnol. 2015, 6, 215–222, doi:10.3762/bjnano.6.20

• and chemical properties, intrinsic very high aspect ratios and tiny tip radii, CNTs looked very promising for LAO-AFM application. Indeed, both single and multi-walled CNTs showed remarkable patterning capabilities [16]. However, this approach has been nearly abandoned, due to the high cost and poor

• substrates in amplitude modulation dynamic mode of operation. In spite of the morphological and chemical resemblance, CNFs and CNTs exhibit fundamental structural differences. Both CNF and CNT are high aspect ratio morphologies (one-dimensional) made primarily of atomic carbon. However, a CNF consists of

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

• Toma Susi,
• Thomas Pichler and
• Paola Ayala

Beilstein J. Nanotechnol. 2015, 6, 177–192, doi:10.3762/bjnano.6.17

• doped carbon nanomaterials. Although phosphorus (P) was theoretically proposed a long time ago as a possible alternative n-type dopant [96], the first experimental reports on phosphorus doping of CNTs and graphene have only been published recently [97][98][99][100]. Like nitrogen, phosphorus has five

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• ; chemical modifications; medical applications; synthesis methods; toxicity; Review Introduction Boron nitride nanotubes (BNNTs) are known as structural analogs of carbon nanotubes (CNTs) but with superior properties [1][2][3]. Although they have structural similarities, they significantly differ in their

• chemical and physical properties. In contrast to CNTs, their electrical properties are not dependent on their chirality and diameter since they have a large band gap of about 5.5 eV. BNNTs also have excellent radiation shielding properties when compared to CNTs [4]. Since the BNNTs are composed of B and N

• atoms, their electronic structures are expected to be rather different from that of CNTs. The charge distribution is asymmetric in B–N bonds in BNNTs as compared to the C–C bonds in CNTs [5]. The electron density of B is attracted to the N atoms due to its higher electronegativity. Thus, the B–N bonds

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• such as fullerenes and carbon nanotubes (CNTs) [23][24][25]. Using these solvents, it is possible to exfoliate graphite, resulting in defect-free graphene layers of high concentration. One limitation of this methodology is its inability to completely eliminate the absorbed solvent from the graphene

• edge carbon atoms. Rolling and sealing graphene An important potential application of exfoliated graphene is the tailored production of other carbon nanostructures such as fullerenes [29] and CNTs. To this effect, we have demonstrated the longstanding visualised strategy of rolling and sealing a

• graphene sheet [30]. This process is possible due to the ultrasonication of graphene upon addition of ferrocenecarboxaldehyde (Fc–CHO) in DMF, Figure 3. Fc–CHO is a reducing agent that prevents oxidation and radical reactions. Additionally, ferrocene derivatives are used in the synthesis of CNTs as carbon

Nanobioarchitectures based on chlorophyll photopigment, artificial lipid bilayers and carbon nanotubes

• Marcela Elisabeta Barbinta-Patrascu,
• Stefan Marian Iordache,
• Ana Maria Iordache,
• Nicoleta Badea and
• Camelia Ungureanu

Beilstein J. Nanotechnol. 2014, 5, 2316–2325, doi:10.3762/bjnano.5.240

• interest in the fields of nanotechnology and biomedicine [1][2][3]. Special attention has been paid to biomimetic membranes that convey biocompatibility to the hybrid materials [4][5][6][7]. One of the building blocks used to construct nanomaterials are carbon nanotubes (CNTs), which are allotropes of

• carbon with a unique nanostructure consisting of graphene sheets (layers of sp2-hybridized carbon atoms, perfectly hexagonally packed in a honeycomb network) rolled up into tubular shapes with a very large length/diameter ratio. This structure gives the unusual properties of CNTs such as: high mechanical

• strength (due to C–C sp2 bonds, which is one of the strongest bonds), flexibility without breakage or damage, high elasticity, good electrical conductivity, and chemical stability. These cylindrical graphene nanotubes are considered one of the most attractive nanomaterials. Applicability of CNTs in the

Electrical contacts to individual SWCNTs: A review

• Wei Liu,
• Christofer Hierold and
• Miroslav Haluska

Beilstein J. Nanotechnol. 2014, 5, 2202–2215, doi:10.3762/bjnano.5.229

• mechanical bending of CNTs lying on the substrate as well as by the chemical inhomogeneity induced during the fabrication process. The transmission line model (TLM) developed for planar devices [47] provides an approach to determine both the contact resistance and the channel resistance. The applicability of

• open ends of nanotube. In this case, the defect sites (dangling bonds) on the ends of the CNTs are intended to provide additional reaction sites to greatly increase the interaction energy between the metal and the CNT [49]. As an example, nanotube/carbide heterojunctions (such as TiC) can be formed at

Advances in NO₂ sensing with individual single-walled carbon nanotube transistors

• Kiran Chikkadi,
• Matthias Muoth,
• Cosmin Roman,
• Miroslav Haluska and
• Christofer Hierold

Beilstein J. Nanotechnol. 2014, 5, 2179–2191, doi:10.3762/bjnano.5.227

• often generate entirely new possibilities, pushing the limits of the accepted boundaries of material properties within which engineers operate. The identification of carbon nanotubes (CNTs) [1][2][3][4] and later, single-walled nanotubes (SWNTs) [5][6] is one example of this phenomenon. One such