One-dimensional Carbon Nanomaterials Research Articles

Effects of Graphene Morphology on Properties of Carbon Nanotube/Polyurethane Film Strain Sensors

The film flexible sensors can convert tiny changes in size or force into electrical signals. They are key components of intelligent devices and wearable devices, and are widely used in human-computer interaction, electronic skin, health monitoring, implantable diagnosis, and other fields. This kind of sensor is generally composed of polymer matrix and conductive components, while carbon nanotubes (CNT) and graphene (GN), as typical one-dimensional and two-dimensional conductive carbon nano-materials, respectively, have been used to build film flexible sensors. In order to explore the relationship between the GN size and thickness, and the performance of film sensors, the GN-CNT/PU composite film sensors were prepared by in situ polymerization of polyurethane (PU) in the presence of GN and CNT. A highly sensitive GN-CNT/PU flexible film sensor was prepared with a high gauge factor (GF) up to 13.15 in a strain range of 0–20%; an exceptionally low percolation threshold of GN is about 0.04 vol% when the CNT content is fixed at 0.2 vol%, which is below the percolation threshold of CNT/PU nanocomposites. The size of the GN layer affects the GFs of the flexible film sensors; a GN with a smaller size can achieve a greater GF. This study paves the way for the better application of different qualities of GN in flexible sensors.

Nitrogen and Sulfur Co-Doped Graphene Quantum Dots Anchored TiO2 Nanocomposites for Enhanced Photocatalytic Activity

Herein, nitrogen (N) and sulfur (S) co-doped graphene quantum dots (GQDs) using different one-dimensional (1-D) carbon nanomaterials as precursors were synthesized, followed by heterojunction formation with TiO2. GQDs exhibit unlike physiochemical properties due to the disproportionate ratio of N and S heteroatoms and dissimilar reaction parameters. Tailored type-II band gap (Eg) alignment was formed with narrowed Eg value that improves photogenerated electron transfer due to π-conjugation. GQDs-TiO2 nanocomposites exhibit remarkably high methylene blue (MB) degradation up to 99.78% with 2.3–3 times elevated rate constants as compared with TiO2. CNF-GQDs-TiO2 demonstrates the fastest MB degradation (60 min) due to the synergistic effect of nitrogen and sulfur doping, and is considered the most stable photocatalyst among prepared nanocomposites as tested up to three cyclic runs. Whereas, C–O–Ti bonds were not only responsible for nanocomposites strengthening but also provide a charge transfer pathway. Moreover, charge transport behavior, generation of active species, and reaction mechanism were scrutinized via free-radical scavenger analysis.

Vibration Control of Diamond Nanothreads by Lattice Defect Introduction for Application in Nanomechanical Sensors.

Carbon nanomaterials, such as carbon nanotubes (CNTs) and graphene sheets (GSs), have been adopted as resonators in vibration-based nanomechanical sensors because of their extremely high stiffness and small size. Diamond nanothreads (DNTs) are a new class of one-dimensional carbon nanomaterials with extraordinary physical and chemical properties. Their structures are similar to that of diamond in that they possess -bonds formed by a covalent interaction between multiple benzene molecules. In this study, we focus on investigating the mechanical properties and vibration behaviors of DNTs with and without lattice defects and examine the influence of density and configuration of lattice defects on the two them in detail, using the molecular dynamics method and a continuum mechanics approach. We find that Young’s modulus and the natural frequency can be controlled by alternating the density of the lattice defects. Furthermore, we investigate and explore the use of DNTs as resonators in nanosensors. It is shown that applying an additional extremely small mass or strain to all types of DNTs significantly changes their resonance frequencies. The results show that, similar to CNTs and GSs, DNTs have potential application as resonators in nano-mass and nano-strain sensors. In particular, the vibration behaviors of DNT resonators can be controlled by alternating the density of the lattice defects to achieve the best sensitivities.

Application of Novel Hollow Carbon Nanosphere Drug-Loading System in Chemotherapy of Esophageal Squamous Cell Carcinoma.

With the continuous improvement of carbon nanotube synthesis and purification technology and the continuous improvement of carbon nanotube dispersion technology, carbon nanotubes have played an increasingly important role in the treatment of malignant tumours. One of the hot spots. Compared with other carbon nanotube materials, the carbon nanosphere drug loading system is more suitable for loading hydrophobic drugs, and the drug loading capacity is higher than other one-dimensional two-dimensional carbon nano-materials. In addition, carbon nanospheres of a suitable size are more easily absorbed by tumour cells and can carry a large amount of drugs for transport in the blood. And the pore structure of the carbon nanosphere is adjustable, and the drug release can be controlled by adjusting the pore size, and the pore diameter is generally less than 10 nm to prevent the drug from being released in advance. Esophageal cancer is one of the most frequently occurring malignancies in China, and the incidence of esophageal cancer ranks 8th in the world. Palliative chemotherapy is t he main treatment method for patients with advanced esophageal cancer. Simultaneous chemoradiotherapy has relatively obvious advantages in improving the survival rate of patients. It is of great significance to study the application of carbon nanosphere drug-loading system in chemoradiotherapy for esophageal squamous cell carcinoma. Therefore, in this study under the hydrothermal method, which is one of the commonly used methods for the synthesis of hollow carbon nanospheres, carboxymethyl chitosan was used as a carbon precursor, and the targeted drug erlotinib was loaded with carbon nanospheres. A new hollow nano-carbon sphere drug-loading system (HNCSDLS) was prepared and related characterizations were carried out. At the same time, the morphology, properties, in vitro and in vivo toxicity, bio-distribution, and anti-tumour activity of HNCSDLS were also studied in this study using scanning electron microscopy flow cytometry, laser confocal, spectrometer, cell proliferation experiment, and in vivo fluorescence imaging experiment Detection. The results of this study indicate that HNCSDLS has high biocom-patibility and stability, can be quickly distributed in the cytoplasm, and avoids lysosomal clearance. It can effectively deliver erlotinib to the tumour site, extend the drug's in vivo circulation time, inhibit tumour growth, reduce the toxicity of erlotinib to heart and kidney tissues, and increase its antitumor activity.

Promoting potential direct interspecies electron transfer (DIET) and methanogenesis with nitrogen and zinc doped carbon quantum dots

Although it has been demonstrated that one-dimensional, two-dimensional, and three-dimensional carbon nanomaterials can improve the CH4 production of anaerobic digestion (AD), the effect of zero-dimensional carbon nanomaterials on AD have not been reported. To expand the application of carbon nanomaterials in AD, the effect of zero-dimensional carbon nanomaterials-carbon quantum dots (CDs) on various feedstocks (c.a. cellulose, glucose, ethanol, and vinegar residue) were investigated in this study. Results have shown that CH4 yield from ethanol was increased by 24.59% (p = 0.396) after adding 5 g/L zinc doped carbon quantum dots (Zn-doped CDs) while that from vinegar residue was dramatically increased by 230% (p = 0.000) using 5 g/L nitrogen doped carbon quantum dots (N-doped CDs). In addition, photoluminescence demonstrated that CDs acted as a capacitor for transmitting and receiving electrons. Furthermore, co-occurrence network analysis revealed that Clostridiales might be used as a signal source to communicate with other species. This study firstly shifted the application of CDs from fluorescence to AD and manifested its positive impact on AD. In short, these findings provided a better understanding on the effects of CDs on different feedstocks of methanogenesis and revealed new evidence of stimulating methanogenesis via CDs.

High-field electromagnetic radiation converts carbon nanotubes to nanoribbons embedded with carbon nanocrystals

One-dimensional carbon nanomaterials such as carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) are promising for future applications in nanoelectronics and nanophotonics due to their unique characteristics such as topological edge states, chirality, and quantum confinement. Despite the chemical unzipping method of producing GNRs from CNTs, using energetic photons to control light–matter interaction and shape materials at the nanoscale has great promise, especially for chemical-free and on-demand manufacturing. Here, we exploit the high electromagnetic field from a Ti:Sapphire femtosecond laser to interact with CNTs, causing ultrafast energy transfer between the photons and the nanotubes and converting them to GNRs and carbon nanocrystals. Probed with scattering-type scanning near-field optical microscopy, the nanoribbons are identified as semiconducting and/or insulating, a strikingly different electronic phase compared with the original metallic CNTs. Our method of employing high-field and nonequilibrium processes with an ultrafast laser to alter the shape and transform the electronic properties is scalable, does not necessitate high-temperature processes, and is highly spatially controllable—conditions that pave the way for manufacturing nanoscale hybrid materials and devices.

Catalyst-free fabrication of one-dimensional N-doped carbon coated TiO2 nanotube arrays by template carbonization of polydopamine for high performance electrochemical sensors

One-dimensional (1D) carbon nanomaterials have extensively explored to fabricate high performance electrochemical sensors for the merits such as high surface area and fast electron transfer kinetics. However, catalytic production of carbon nanomaterials often suffers from misinterpretations of electrochemical signals from the catalyst residue and complicated production steps. Herein, we reported a catalyst-free method to produce 1D N-doped carbon coated TiO2 nanotube arrays (N-doped C/TiO2 NTAs) by template carbonization of polydopamine nanofilm coated anodized TiO2 NTAs. The N-doped C/TiO2 NTAs possesses a uniform structure with an inner diameter for an individual nanotube of about 80 nm and a length of about 8 µm. The carbon coating is about 10 nm in thickness and is doped by nitrogen from the polydopamine precursor. The N-doped C/TiO2 NTAs electrode exhibits an extremely high electrochemical activity with the heterogeneous charge transfer rate constants k0 greater than 0.5 cm/s for Fe(CN)63−/4− redox couple. Simultaneous determination of ascorbic acid, dopamine and uric acid has been demonstrated with the linear ranges of 100–3000 μM, 5–50 μM and 0.1–150 μM, respectively and detection limits (S/N = 3) of 1.8 μM, 0.015 μM and 0.11 μM, respectively.

Low thermal conductivity of peanut-shaped carbon nanotube and its insensitive response to uniaxial strain

Motivated by the experimental synthesis of peanut-shaped carbon nanotubes (PSNTs) that combine the novel features of fullerene and carbon nanotubes (CNTs), we study the thermal conductivity of a PSNT (1dp08) and its response to different strains by using non-equilibrium molecular dynamics simulations and lattice dynamics together with density functional theory. We find that the thermal conductivity of the PSNT is reduced by more than 90% as compared to that of CNTs, and remains almost the same when different strains applied, exhibiting very different behaviors from that of CNTs, where the thermal conductivity decreases monotonically with the increase of strain. Through phonon mode calculations, we show that the reduced phonon group velocity, phonon lifetime and the vibrational mismatch are responsible for the low thermal conductivity of the PSNT, and the insensitive response of thermal conductivity to strain is due to the insensitivity of its phonon density of states and group velocity to strain. These features endow the PSNT with the potential applications in thermal devices, and add new features to one-dimensional carbon nanomaterials going beyond conventional CNTs.

Recent advances in nanomaterials for high-performance Li–S batteries

This article reviews nanotechnology as a practical solution for improving lithium-sulfur batteries. Lithium-sulfur batteries have been widely examined because sulfur has many advantageous properties such as a high crustal abundance, low environmental impact, low cost, high gravimetric (2600 W h kg−1) and volumetric (2800 W h L−1) energy densities, assuming complete conversion of sulfur to lithium sulfide (Li2S) upon lithiation. However, lithium-sulfur batteries have not yet reach commercialization due to demerits involving the formation of soluble lithium polysulfides (Li2Sn, n = 3–8), low electrical conductivity, and low loading density of sulfur. These issues arise mainly due to the polysulfide shuttle phenomenon and the inherent insulating nature of sulfur. To overcome these issues, strategies have been pursued using nanotechnology applied to porous carbon nanocomposites, hollow one-dimensional carbon nanomaterials, graphene nanocomposites, and three-dimensional carbon nanostructured matrices. This paper aims to review various solutions pertaining to the role of nanotechnology in synthesizing nanoscale and nanostructured materials for advanced and high-performance lithium–sulfur batteries. Furthermore, we highlight perspective research directions for commercialization of lithium–sulfur batteries as a major power source for electric vehicles and large-scale electric energy storage.

The combination of Diels-Alder reaction and redox polymerization for preparation of functionalized CNTs for intracellular controlled drug delivery.

Carbon nanotubes (CNTs) are a novel type of one-dimensional carbon nanomaterials that have been widely utilized for biomedical applications such as drug delivery, cancer photothermal treatment owing to their high surface area and unique interaction with cell membranes. However, their biomedical applications are still impeded by some drawbacks, including poor water dispersibility, lack of functional groups and toxicity. Therefore, surface modification of CNTs to overcome these issues should be importance and of great interest. In this work, we reported for the first time that CNTs could be surface modification through the combination of Diels-Alder (D-A) reaction and redox polymerization, this strategy shows the advantages of mild reaction conditions, water tolerance, low temperature and hydroxyl-surfaced initiator. In this modification procedure, the hydroxyl groups were introduced on the surface of CNTs through the D-A reaction that was adopted for grafting the copolymers, which were initiated by the Ce(IV)/HNO3 redox system using the hydrophilic and biocompatible poly(ethylene glycol) methyl ether methacrylate (PEGMA) and carboxyl-rich acrylic acid (AA) as monomers. The final CNTs-OH-PAA@PEGMA composites were characterized by a series of characterization techniques. The drug loading and release results suggested that anticancer agent cis‑platinum (CDDP) could be loaded on CNTs-OH-PAA@PEGMA composites through coordination with carboxyl groups and drug release behavior could be controlled by pH. More importantly, the cell viability results clearly demonstrated that CNTs-OH-PAA@PEGMA composites displayed low toxicity and the drug could be transported in cells and still maintain their therapeutic effects.

Toxicity of Zero- and One-Dimensional Carbon Nanomaterials.

The zero (0-D) and one-dimensional (1-D) carbon nanomaterials have gained attention among researchers because they exhibit a larger surface area to volume ratio, and a smaller size. Furthermore, carbon is ubiquitously present in all living organisms. However, toxicity is a major concern while utilizing carbon nanomaterials for biomedical applications such as drug delivery, biosensing, and tissue regeneration. In the present review, we have summarized some of the recent findings of cellular and animal level toxicity studies of 0-D (carbon quantum dot, graphene quantum dot, nanodiamond, and carbon black) and 1-D (single-walled and multi-walled carbon nanotubes) carbon nanomaterials. The in vitro toxicity of carbon nanomaterials was exemplified in normal and cancer cell lines including fibroblasts, osteoblasts, macrophages, epithelial and endothelial cells of different sources. Similarly, the in vivo studies were illustrated in several animal species such as rats, mice, zebrafish, planktons and, guinea pigs, at various concentrations, route of administrations and exposure of nanoparticles. In addition, we have described the unique properties and commercial usage, as well as the similarities and differences among the nanoparticles. The aim of the current review is not only to signify the importance of studying the toxicity of 0-D and 1-D carbon nanomaterials, but also to emphasize the perspectives, future challenges and possible directions in the field.

Template-Assisted Synthesis of Luminescent Carbon Nanofibers from Beverage-Related Precursors by Microwave Heating.

Luminescent carbon nanomaterials are important materials for sensing, imaging, and display technologies. This work describes the use of microwave heating for the template-assisted preparation of luminescent carbon nanofibers (CNFs) from the reaction of a range of beverage-related precursors with the nitrogen-rich polyethyleneimine. Highly luminescent robust carbon fibers that were 10 to 30 μm in length and had a diameter of 200 nm were obtained under moderate conditions of temperature (250–260 °C) and a short reaction time (6 min). The high aspect ratio fibers showed wavelength-dependent emission that can be readily imaged using epifluorescence. The development of these multi-emissive one-dimensional (1D) carbon nanomaterials offers potential for a range of applications.

Cyclic piezoresistive effect in poly(dimethylsiloxane)/carbon nanofiber composites for large strain Sensing applications

Adding conductive one-dimensional carbon nanomaterials to poly(dimethysiloxane) can form bio-compatible composites with significant electromechanical (piezoresistive) response. This effect can be effectively tuned by controlling the carbon nanofiller size, concentration, and distribution. However, to be applied as strain sensors, the composite material has to meet mechanical, sensitivity, temperature stability, and reliability requirements. Here we report on the study of cyclic electromechanical behaviors of poly(dimethysiloxane)/carbon nanofiber composites under different temperatures. Through mechanical training, reproducible and sensitive piezoresistive response suitable for large strain sensing can be obtained.

Carbon Nitride Nanothread Crystals Derived from Pyridine.

Carbon nanothreads are a new one-dimensional sp3 carbon nanomaterial. They assemble into hexagonal crystals in a room temperature, nontopochemical solid-state reaction induced by slow compression of benzene to 23 GPa. Here we show that pyridine also reacts under compression to form a well-ordered sp3 product: C5NH5 carbon nitride nanothreads. Solid pyridine has a different crystal structure from solid benzene, so the nontopochemical formation of low-dimensional crystalline solids by slow compression of small aromatics may be a general phenomenon that enables chemical design of properties. The nitrogen in the carbon nitride nanothreads may improve processability, alters photoluminescence, and is predicted to reduce the bandgap.

Graphene bonded carbon nanofiber aerogels with high capacitive deionization capability

We herein report a fascinating carbon aerogel that has a unique framework structure consisting of one-dimensional (i.e. nanofibers) and two-dimensional (i.e. graphene) carbon nanomaterials. Such a carbon aerogel was prepared by carbonization of electrospun polyacrylonitrile with graphene oxide sheets (GO). The nanofiber-graphene interconnection within the aerogel considerably enhances the electrochemical characteristics. The aerogel showed an electrosorption capacity of 15.7 mg g−1 in 500 mg L−1 NaCl solution, and the CDI cell exhibited stable performance over 100 cycles. Moreover, the carbon aerogel has good electrical conductivity and faster electron transfer rate. Such a cross-linked porous aerogel may provide a new strategy for highly efficient CDI applications.

Mechanochemical Synthesis of Carbon Nanothread Single Crystals.

Synthesis of well-ordered reduced dimensional carbon solids with extended bonding remains a challenge. For example, few single-crystal organic monomers react under topochemical control to produce single-crystal extended solids. We report a mechanochemical synthesis in which slow compression at room temperature under uniaxial stress can convert polycrystalline or single-crystal benzene monomer into single-crystalline packings of carbon nanothreads, a one-dimensional sp3 carbon nanomaterial. The long-range order over hundreds of microns of these crystals allows them to readily exfoliate into fibers. The mechanochemical reaction produces macroscopic single crystals despite large dimensional changes caused by the formation of multiple strong, covalent C-C bonds to each monomer and a lack of reactant single-crystal order. Therefore, it appears not to follow a topochemical pathway, but rather one guided by uniaxial stress, to which the nanothreads consistently align. Slow-compression room-temperature synthesis may allow diverse molecular monomers to form single-crystalline packings of polymers, threads, and higher dimensional carbon networks.

Nano-bio interactions between carbon nanomaterials and blood plasma proteins: why oxygen functionality matters

Carbon nanomaterials are some of the most versatile nanomaterials. Along with increasing explorations into their utilization in a plethora of biological and biomedical applications, there have been emerging interests and needs in understanding the molecular hemocompatibility of these engineered nanomaterials when coming into contact with blood. Here, we evaluate the nano-bio interactions of one-dimensional (1D) and two-dimensional (2D) carbon nanomaterials with blood plasma proteins. Different facets of the nanomaterial–protein interactions, specifically, the adsorption, equilibrium binding and conformational stability of proteins upon association with carbon nanomaterials are established, based on the quantification of various parameters, such as association constant, binding cooperativity and protein secondary structural change. In light of our data, we demonstrate that the carbon nanomaterial–plasma protein interactions may be significantly influenced by the density of the oxygenated functionalities of the nanomaterials and to a certain extent, their dimensionality and surface area. This work offers a broad insight into the nano-bio interactions between carbon nanomaterials and blood plasma proteins and provides a strong basis for the design and use of 1D and 2D carbon nanomaterials for a wide variety of bioapplications.

Biomimetic PEGylation of carbon nanotubes through surface-initiated RAFT polymerization

Carbon nanotubes (CNTs) are a type of one-dimensional carbon nanomaterials that possess excellent physicochemical properties and have been potentially utilized for a variety of applications. Surface modification of CNTs with polymers is a general route to expand and improve the performance of CNTs and has attracted great research interest over the past few decades. Although many methods have been developed previously, most of these methods still showed some disadvantages, such as low efficiency, complex experimental procedure and harsh reaction conditions etc. In this work, we reported a practical and novel way to fabricate CNTs based polymer composites via the combination of mussel inspired chemistry and reversible addition fragmentation chain transfer (RAFT) polymerization. First, the amino group was introduced onto the surface of CNTs via self-polymerization of dopamine. Then, chain transfer agent can be immobilized on the amino groups functionalized CNTs to obtain CNT-PDA-CTA, which can be utilized for surface-initiated RAFT polymerization. A water soluble and biocompatible monomer poly(ethylene glycol) monomethyl ether methacrylate (PEGMA) was adopted to fabricate pPEGMA functionalized CNTs through RAFT polymerization. The successful preparation of CNTs based polymer composites (CNT-pPEGMA) was confirmed by transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray photoelectron spectroscopy in details. The CNT-pPEGMA showed good dispersibility and desirable biocompatibility, making them highly potential for biomedical applications. More importantly, a large number of CNTs based polymer composites could also be fabricated through the same strategy when different monomers were used due to the good monomer adaptability of RAFT polymerization. Therefore, this strategy should be a general method for preparation of various multifunctional CNTs based polymer composites.

Optimizing the thermoelectric performance of graphyne nanotube via applying radial strain

Graphyne nanotubes (GNTs) are a new kind of one-dimensional carbon nanomaterials containing both sp and sp2 hybridization states. In this paper, taking gamma-GNTs as an example, we investigate the effect of radial strain on the thermoelectric conversion efficiency by means of nonequilibrium Green's function method as implemented in the density functional based tight-binding framework. The results reveal that the thermoelectric figure of merit could be obviously improved by applying appropriate radial strain. Such enhancement mainly originates from the reserved pristine electronic transport properties and significant suppressed phononic thermal conductance. However, as radial strain increases further, such enhanced thermoelectric performance will be reduced rapidly, which is attributed to the serious electron scattering caused by the change of bonding configuration of GNTs. These phenomena are quite different from previous studies that axial strain has a weak influence on the thermoelectric performance of carbon nanotubes and graphene nanoribbons. The findings presented in this paper indicate that radial strain is a viable way to optimize the thermoelectric performance of GNTs and could provide helpful theoretical guideline for designing and fabricating GNT-based thermoelectrics.

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

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.