Engineering of oriented carbon nanotubes in composite materials

• Razieh Beigmoradi,
• Abdolreza Samimi and
• Davod Mohebbi-Kalhori

Beilstein J. Nanotechnol. 2018, 9, 415–435, doi:10.3762/bjnano.9.41

• and production ability of the fibers in semi-industrial quantities [44]. The two methods commonly used to make CNT/nanofiber are described below. Electrospinning: Electrospinning (ES) can be used to produce fibers from a viscous solution of polymer/CNTs, it is also employed for aligning CNTs in the

• fibers. In this method, a high voltage DC current (about 25 kV) is used between a charged polymer and a metallic collector to produce continuous filaments. Experiments revealed that the functionalized CNTs are aligned in the direction of the axis of the nanofiber polymers [45][46][47]. Figure 7 shows a

• can be effective in developing the method [111]. The magnetic field strength and sample size are the limiting parameters of this method. Moreover, as previously mentioned, the CNTs are aligned in the direction of the axis of electrospun nanofiber polymers. In new research, well-aligned electrospun

Dry adhesives from carbon nanofibers grown in an open ethanol flame

• Christian Lutz,
• Julia Syurik,
• C. N. Shyam Kumar,
• Christian Kübel,
• Michael Bruns and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2017, 8, 2719–2728, doi:10.3762/bjnano.8.271

• fabricated arrays of carbon nanofibers with different degrees of orientation. Inspired by the dry adhesive system of geckos we investigated the adhesive properties of such carbon nanofiber arrays with ordered and random orientation. AFM-based force spectroscopy revealed that adhesion force and energy rise

• linear with preload force. Carbon nanofibers oriented by a magnetic field show a 68% higher adhesion (0.66 N/cm2) than the randomly oriented fibers. Endurance tests revealed that the carbon nanofiber arrays withstand 50.000 attachment/detachment cycles without observable wear. Keywords: adhesion; atomic

• growth of CNFs in an open flame as discussed below. Randomly oriented CNFs were observed when no magnetic field was applied (Figure 3a). The catalytic particles can be seen at the end of each nanofiber, indicating a tip-growth mechanism of the CNFs. The bright points in the SEM images most likely

Fabrication of carbon nanospheres by the pyrolysis of polyacrylonitrile–poly(methyl methacrylate) core–shell composite nanoparticles

• Dafu Wei,
• Youwei Zhang and
• Jinping Fu

Beilstein J. Nanotechnol. 2017, 8, 1897–1908, doi:10.3762/bjnano.8.190

• carbonization treatments, polyacrylonitrile (PAN) can be converted into carbon. High-performance carbon fibers, carbon nanofiber membranes, 3D-ordered carbon materials, and carbon nanoparticles have been fabricated from various PAN precursors [28][29][30][31][32][33][34][35]. Discrete and well-defined carbon

Oxidative stabilization of polyacrylonitrile nanofibers and carbon nanofibers containing graphene oxide (GO): a spectroscopic and electrochemical study

• İlknur Gergin,
• Ezgi Ismar and
• A. Sezai Sarac

Beilstein J. Nanotechnol. 2017, 8, 1616–1628, doi:10.3762/bjnano.8.161

• during carbonization. Thus, the understanding of the oxidation mechanism is an essential part of the production of CNF. The oxidation process of polyacrylonitrile was studied and nanofiber webs containing graphene oxide (GO) are obtained to improve the electrochemical properties of CNF. Structural and

• interior pores filled with electrolyte. Keywords: carbon nanofiber; graphene oxide; oxidized polyacrylonitrile (PAN); Introduction Carbon nanofibers are of great interest because of their chemical similarity to fullerenes and carbon nanotubes. Carbon nanofibers (CNF) have promising electrochemical and

• micrometers and exhibit a high surface area and a high electrical conductivity. Also, nanofibers can be used with polymeric structures to generate composite materials to improve the electrochemical properties of polymeric structures [1][2][3]. Nanofiber-reinforced polymeric structures present improved

Fabrication of hierarchically porous TiO₂ nanofibers by microemulsion electrospinning and their application as anode material for lithium-ion batteries

• Jin Zhang,
• Yibing Cai,
• Xuebin Hou,
• Xiaofei Song,
• Pengfei Lv,
• Huimin Zhou and
• Qufu Wei

Beilstein J. Nanotechnol. 2017, 8, 1297–1306, doi:10.3762/bjnano.8.131

• electrospun into nanofibers by a custom-made electrospinning setup consisting of a high voltage power supply, a syringe pump and a grounded nanofiber collector covered with aluminium foil. During electrospinning, a positive voltage of 20 kV was applied between the needle tip and grounded collector at a

• the number of channels in each nanofiber decreased as the content of paraffin oil increased. This is because the pores stemmed from the vacancies of oil droplets after calcination, and a larger oil droplets were formed when more paraffin oil was added into the microemulsion [31]. The SEM image of

• unmodified TiO2 nanofibers in Figure 4g reveals solid structures without pores in the cross-section. This sample was used as reference in the following investigation. As shown in Figure 4h, a representative TEM image of a single porous nanofiber confirms that the pores inside the fibers were oriented and

Needs and challenges for assessing the environmental impacts of engineered nanomaterials (ENMs)

• Michelle Romero-Franco,
• Hilary A. Godwin,
• Muhammad Bilal and
• Yoram Cohen

Beilstein J. Nanotechnol. 2017, 8, 989–1014, doi:10.3762/bjnano.8.101

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

• Alexandra M. Greiner,
• Adria Sales,
• Hao Chen,
• Sarah A. Biela,
• Dieter Kaufmann and
• Ralf Kemkemer

Beilstein J. Nanotechnol. 2016, 7, 1620–1641, doi:10.3762/bjnano.7.155

• responsive polymer (e-beam resist) in order to obtain a pattern for further processing. Like focused-ion beam nanolithography, the e-beam nanolithography can also deposit materials at the nanoscale level [68]. Electrospinning is a technique that allows for the fabrication of a nanofiber-based meshwork. A

Development of adsorptive membranes by confinement of activated biochar into electrospun nanofibers

• Mehrdad Taheran,
• Mitra Naghdi,
• Satinder K. Brar,
• Emile Knystautas,
• Mausam Verma,
• Rao. Y. Surampalli and
• Jose. R. Valero

Beilstein J. Nanotechnol. 2016, 7, 1556–1563, doi:10.3762/bjnano.7.149

• mass spectrometer (Thermo Finnigan, USA). The daughter ions identified for CTC in LDTD were 464 and 444 Da. The detailed method was explained elsewhere by Pulicharla et al. [23]. Results and Discussion Nanofiber morphology The SEM micrographs of fabricated nanofibrous membrane with different contents

• structure [26][30]. The shift of the exothermic peak to lower temperatures from pure PAN powder to PAN nanofiber (NFM-0%) suggests that cyclization is more easily initiated due to molecular rearrangement during electrospinning that resulted in an improved orientation in molecular chains. On the other hand

Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• In2O3/PANI nanofibers with reliable sensing properties towards NH3 were synthesized by electrospinning, calcination and in situ polymerization. The gas sensors based on In2O3/PANI nanofibers exhibited a higher sensitivity than pure PANI. The In2O3/PANI-2 nanofiber sensor exhibited the best sensitivity

• to NH3 vapor at room temperature, and this sensor was further investigated for its selectivity by interfering with methanol, ethanol and acetone vapors. The results indicated that the In2O3/PANI-2 nanofiber sensor had excellent selectivity, good repeatability and reversibility. The enhancement of gas

• sensing performance of In2O3/PANI nanofiber sensor may be attributed to formation of a p–n junction between In2O3 and PANI, which existence is confirmed by the I–V characteristics. Schematic of the preparation of In2O3/PANI composite nanofibers. a) XRD pattern of In2O3 nanofibers. FTIR spectra of b) In

Improved lithium-ion battery anode capacity with a network of easily fabricated spindle-like carbon nanofibers

• Mengting Liu,
• Wenhe Xie,
• Lili Gu,
• Tianfeng Qin,
• Xiaoyi Hou and
• Deyan He

Beilstein J. Nanotechnol. 2016, 7, 1289–1295, doi:10.3762/bjnano.7.120

• capacity of 875.5 mAh g−1 after 200 cycles and 1005.5 mAh g−1 after 250 cycles with a significant coulombic efficiency of 99.5%. Keywords: carbon nanofiber network; electrospinning; lithium-ion battery; manganese oxide; nitrogen modification; Introduction Lithium-ion batteries (LIBs) have been identified

• that the major component of the obtained beaded nanofiber network is amorphous carbon with a small amount of MnO, which is in accordance with the XRD results. Moreover, an XPS investigation was performed to clarify the elements and their chemical states on the surface of the samples. All the XPS

• %, respectively. The electrochemical performance of the beaded nanofiber carbon network anchored with MnO and N was investigated as a working electrode of CR2032-type coin cell with lithium foil as the counter and reference electrodes. Figure 3a shows the typical cyclic voltammetry (CV) curves of the initial

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• in poly(phenylene benzobisoxazole (PBO) matrix and found an improvement of mechanical properties [137]. Along with an increase of tensile strength, SWNTs can increase the strain prior to failure. Nanofiber alignment is suitable to improve strength and modulus. However, it was observed that results

Hierarchical coassembly of DNA–triptycene hybrid molecular building blocks and zinc protoporphyrin IX

• Rina Kumari,
• Sumit Singh,
• Mohan Monisha,
• Sourav Bhowmick,
• Anindya Roy,
• Neeladri Das and
• Prolay Das

Beilstein J. Nanotechnol. 2016, 7, 697–707, doi:10.3762/bjnano.7.62

• block of the nanofibers. A notable change in photocatalytic efficiency of Zn PpIX was observed when it was inside the TPA–DNA scaffold. The significant increase in ROS generation by Zn PpIX when trapped in this biocompatible DNA–TPA hybrid nanofiber may be an effective tool to explore photodynamic

• constant for all the measurements. The percentage of enhancement in degree of oxidation (% EDO) of DHR 123 in the presence of DNA–TPA Zn PpIX nanofiber at λmax = 500 nm and λem = 534 nm was determined by using the equation as follows: where I0 is the absorption or the fluorescent intensity of oxidized DHR

• 123 by free Zn PpIX, and I is the fluorescent or absorption intensity in the presence of DNA–Zn PpIX and DNA–Zn PpIX nanofiber upon 2 min UV irradiation. Computational study In order to resolve the formation of higher ordered structures from assemblies of triconjugated DNA–TPA system, we conducted

Novel roles for well-known players: from tobacco mosaic virus pests to enzymatically active assemblies

• Claudia Koch,
• Fabian J. Eber,
• Carlos Azucena,
• Alexander Förste,
• Stefan Walheim,
• Thomas Schimmel,
• Alexander M. Bittner,
• Holger Jeske,
• Hartmut Gliemann,
• Sabine Eiben,
• Fania C. Geiger and
• Christina Wege

Beilstein J. Nanotechnol. 2016, 7, 613–629, doi:10.3762/bjnano.7.54

• addressable coupling sites exposed on their outer and sometimes inner surfaces, they offer intriguing possibilities for use as nanocontainers for the encapsidation or fabrication of compounds, or as nanofiber scaffolds for the immobilization and presentation of functional units. Most of the novel approaches

Nanofibers for drug delivery – incorporation and release of model molecules, influence of molecular weight and polymer structure

• Jakub Hrib,
• Jakub Sirc,
• Radka Hobzova,
• Zuzana Hampejsova,
• Zuzana Bosakova,
• Marcela Munzarova and
• Jiri Michalek

Beilstein J. Nanotechnol. 2015, 6, 1939–1945, doi:10.3762/bjnano.6.198

• these applications [8]. Although several methods of nanofiber preparation have been invented [9], electrospinning technique can be considered as a simple and versatile method for the production of continuous polymeric nanofibrous mats formed of nano- to micro-sized fibers [10][11][12][13][14]. Moreover

• , elemental analysis, IR spectroscopy and melting point measurements. The needle-free electrospinning process was optimized for each type of nanofiber with respect to the different physicochemical properties of polymers. SEM images revealed that the textures of all resultant samples were homogenous and free

• not noticeably influence the nanofiber structure. According to the results of morphological characterization, the nanofibrous structures remained similar to those of nanofibers without model molecules, even for nanofibers that contained PEG 20 (Figure 2d–f). Clusters or other artifacts were not

Tunable white light emission by variation of composition and defects of electrospun Al₂O₃–SiO₂ nanofibers

• Jinyuan Zhou,
• Gengzhi Sun,
• Hao Zhao,
• Xiaojun Pan,
• Zhenxing Zhang,
• Yujun Fu,
• Yanzhe Mao and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 313–320, doi:10.3762/bjnano.6.29

• . Strong light emission was observed from the Al2O3–SiO2 hetero-nanofibers with tunable emission from bluish-white to yellow-white. The possible origins of each PL band in this composite nanofiber were also discussed. Results and Discussion Crystalline structures Figure 1 shows the XRD patterns of the

• Figure 2d and Figure 2e, respectively) results in the coarsening of the surface of the fiber, further implying the precipitation of mullite nanocrystals from the inside to the surface of the fibers during the calcination. Comparably, the pure SiO2 nanofiber has a diameter of ≈100 nm with smooth surface

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

• -AFM, because it regulates the minimum feature size and the electric field. For instance, the feasibility of carbon nanotube (CNT)-functionalized tips showed great promise for LAO-AFM, yet, the fabrication of CNT tips presents difficulties. Here, we explore the use of a carbon nanofiber (CNF) as the

• of field-induced, chemical process efficiency. Keywords: carbon nanofiber; dynamic mode; local anodic oxidation; nanopatterning; Introduction Scanning probe lithography (SPL) is increasing its relevance among currently employed methods towards miniaturization and investigations at the nanometer

• control upon making CNT probes, as well as characteristic tip-to-tip differences, such as length, diameter, and operational complications, such as CNT buckling [15][16]. In this work, we explore the use of a carbon nanofiber (CNF) as the tip apex of AFM probes for the application of LAO-AFM on silicon

Controlled synthesis and tunable properties of ultrathin silica nanotubes through spontaneous polycondensation on polyamine fibrils

• Jian-Jun Yuan,
• Pei-Xin Zhu,
• Daisuke Noda and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2013, 4, 793–804, doi:10.3762/bjnano.4.90

• ][23][24][25][26][27][28][29] or amine-modified polysaccharides [30] have been used as template for the formation of silica nanotubes. For example, Yuwono et al. [23] reported the use of peptide-amphiphile nanofiber templates in order to direct the synthesis of hollow silica nanotubes with outer

Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone) composite nanofibers

• Ji-Hong Chai and
• Qing-Sheng Wu

Beilstein J. Nanotechnol. 2013, 4, 189–197, doi:10.3762/bjnano.4.19

• nanofiber membrane, and we could see that the membrane is white. Figure 1b reveals that these nanofibers interdigitate to form a feltlike film. The surface morphologies of fibers are rough and the diameter distribution is from 70 to 100 nm and tens of microns in length. Compared with the blank PVP nanofiber

• membrane, Figure 1c shows the optical photograph of the composite Fc/PVP nanofiber membrane. The Fc was loaded at an amount of 45 wt % with respect to PVP mass in the nanofibers, and the membrane clearly changed to pale yellow, which was attributed to the presence of Fc. The surface morphologies of the

• fibers became porous and the diameter obviously increased with the distribution ranging from 100 to 200 nm (Figure 1d). The high surface-to-volume ratio improved the antibacterial activity of the composite Fc/PVP nanofiber membrane. As seen from the presented SEM micrographs (Figure 1d), no Fc crystals

Surface functionalization of aluminosilicate nanotubes with organic molecules

• Wei Ma,
• Weng On Yah,
• Hideyuki Otsuka and
• Atsushi Takahara

Beilstein J. Nanotechnol. 2012, 3, 82–100, doi:10.3762/bjnano.3.10

• introducing a phosphonic acid group to the corresponding molecules. The optical and photophysical properties of these conjugated-molecule-decorated imogolite nanotubes were characterized. Moreover, poly(3-hexylthiophene) (P3HT) chains were further hybridized with HT3P modified imogolite to form a nanofiber

• imogolite surface [61]. In addition, the absence of the 1004 cm–1 band, which is assigned to P–O–H groups [62][63], was another indication that HT3P molecules were chemisorbed onto the surface of the imogolite nanofiber. The FTIR spectrum of HT3OP/imogolite hybrid as shown in Figure 16b gives a similar

• negative charge to imogolite, which restricts the effective motion of positively charged species on the imogolite surface. Poly(3-hexyl thiophene)/imogolite nanofiber hybrid Polythiophenes are one of the well-known families of conductive polymers, and their physicochemical properties, such as their

Approaches to nanostructure control and functionalizations of polymer@silica hybrid nanograss generated by biomimetic silica mineralization on a self-assembled polyamine layer

• Jian-Jun Yuan and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2011, 2, 760–773, doi:10.3762/bjnano.2.84

• and facilely functionalized makes our nanograss potentially important for device-based application in microfluidic, microreactor and biomedical fields. Keywords: biomimetic silica mineralization; linear polyethyleneimine; nanofiber; nanograss; thin film; Introduction Silica-based, one-dimensional

Formation of precise 2D Au particle arrays via thermally induced dewetting on pre-patterned substrates

• Dong Wang,
• Ran Ji and
• Peter Schaaf

Beilstein J. Nanotechnol. 2011, 2, 318–326, doi:10.3762/bjnano.2.37

• nanoparticles, due to their wide range of potential applications in plasmonics [1][2], magnetic memories [3], DNA detection [4], and catalysis for nanowire and nanofiber growth [5][6]. Nanoparticle arrays are typically fabricated either by chemical processes based on self-assembly or by lithography based