Application Of Carbon Nanotubes Research Articles

Characterization of Composite Materials Using Carbon Nano Tube Carboxy Group Introduction and Aluminum Oxide Synthesis

The high integration and high density of semiconductor packages are generating increased heat in electronic devices, leading to issues such as reduced lifespan and malfunctions in electronic devices. In response, research on thermal interface materials is being conducted to address heat generated from heat sources, and various studies, particularly those applying carbon nano tube, are notable in this regard. However, in the case of carbon nano tube, there are challenges in industrial application due to the occurrence of cohesive forces through van der Waals interactions. Therefore, in this study, the characteristics were analyzed through the formation of carbon nano tube carboxyl groups (–COOH) and the synthesis of aluminum oxide via chloride (–COCl) formation. After the chloride process, a functional group –COCl was confirmed at 430 cm−1. It was confirmed that the electrical properties were improved as a result of the CNT, CNT carboxyl, and chloride process. It is believed that the electrical properties improved as impurities were removed during the acid treatment process. In addition, it is believed that the electrical properties were improved due to the increase in intermolecular forces between CNTs. Through this, it is determined that the application of carbon nano tube and aluminum oxide composite materials can be highly beneficial for thermal conductivity heat dissipation filler applications.

Effect of carbon nanotubes on mechanical properties of aluminum matrix composites: A review

Abstract Carbon nanotubes (CNTs) are renowned for their low density, high elastic modulus, and exceptional electrical and thermal properties. The continuously developing applications of CNTs provide higher specific stiffness and strength for composite materials. The unique characteristics of CNTs make them ideal reinforcing particles in aluminum matrix composites (AMMCs), which generally exhibit excellent mechanical properties. CNTs/AMMCs are usually prepared using methods such as powder metallurgy, casting, spray deposition, and reactive melting. The uniform diffusion of CNTs in composites is crucial for enhancing the properties of CNTs/AMMCs. The properties of CNTs/AMMCs largely depend on the content, morphology, and distribution of reinforcements in the matrix and the interaction between reinforcements and the matrix. By adding an appropriate volume fraction of CNTs, the hardness, tensile strength, compressive strength, and electrical properties of CNTs/AMMCs were significantly improved. The effects of CNT content on the mechanical properties of CNTs/AMMCs, including the tensile strength, yield strength, compressive strength, stress–strain curve behavior, elastic modulus, hardness, creep, and fatigue behavior, were revealed. The design of microstructure, optimization of the preparation process, and optimization of composition can further improve the mechanical properties of CNTs/AMMCs and expand their application in engineering. The design concept of integrating material homogenization and functional unit structure through biomimetic design of novel gradient structures, layered structures, and multi-level twin structures further optimizes the composition and microstructure of CNTs/AMMCs, which is the key to further obtaining high-performance CNTs/AMMCs. As a multifunctional composite material, CNTs/AMMCs have broad application prospects in fields such as air force, military, aerospace, automation, and electronics. Moreover, CNTs/AMMCs have potential applications in cell therapy, tissue engineering, and other areas.

Effect of purification methods on the quality and morphology of plastic waste-derived carbon nanotubes

Recent innovative research efforts on the usage of plastic wastes as a cheap carbon source for carbon nanotubes (CNTs) production have emerged as a low-cost and sustainable means of producing CNTs. However, plastic waste-derived CNTs are rarely used in some purity-sensitive and high-alignment needed applications due to the poor quality of CNTs resulting from the abundance of impurities such as non-crystalline amorphous carbon, metallic nanoparticles, and other impurities. Therefore, purification is a crucial issue to be addressed to fully harness all potential applications of CNTs derived from waste plastic materials. Here, the effect of employing different purification methods on the morphology and purity of waste plastic-derived CNTs was investigated. CNTs were synthesized using waste polypropylene plastic as carbon feedstock via a single-stage catalytic chemical vapour deposition (CVD) technique. As-produced CNTs were purified using liquid-phase oxidation (chemical oxidation in nitric acid), gas-phase oxidation in air, and a combination of both liquid- and gas-phase oxidation methods. The synthesized and purified CNTs were characterized for morphology, purity, surface functional groups, thermal stability, and crystallinity using Transmission electron microscopy (TEM), Raman spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), and X-ray diffraction (XRD), respectively. Results obtained showed that a combination of both liquid and gas phase oxidation purification techniques resulted in purer, better quality, and less defective CNTs with an IG’/IG value of 0.89 and ID/IG value of 0.86, while chemically treated CNTs (CNT-PC) presented more structurally defective CNTs and shortened nanotubes compared to other investigated treatment methods with an ID/IG value of 0.96. CNTs purified by a multi-step protocol (CNT-PAC) showed the highest weight loss of 72.3% indicating the highest quality and the presence of filamentous carbon. This study confirms that the choice of purification techniques influences the morphology and quality of plastic-derived CNTs.

Evolving Advances in the Applications of Carbon Nanotubes (CNTs) for Management of Rheumatoid Arthritis (RA).

Rheumatoid arthritis (RA) is a chronic condition causing joint pain and inflammation that has now spurred the interest in nanotechnology-based drug delivery for more effective treatment, and in this regard, carbon nanotubes (CNTs) are being explored for their potential to deliver the drugs steadily to manage the RA. Many investigators have been investigating both single-walled carbon nanotubes (SWCNT) as well as multi-walled carbon nanotubes (MWCNT) for managing arthritis via targeted drug delivery. Moreover, functionalized CNTs show promise in delivering the drugs precisely and in a controlled manner, thereby minimizing toxicity. However, research on applications of CNTs as drug carriers for RA remains limited, thus necessitating further exploration to address the various challenges. In this present piece of writing, challenges in RA treatment and the advances in applications of CNTs for RA management are reported, consequently reflecting the CNTs as advanced drug delivery vehicles for arthritis treatment.

Role of carbon nanotubes in remediation of pharmaceutical wastewater

AbstractThe discharge of wastewater from the pharmaceutical industry poses risks of detrimental effects on various ecosystems. The presence of hazardous substances in pharmaceutical wastewater is a matter of global concern due to its association with multiple disorders, including disruptions in endocrine hormones and significant chronic toxicity. As research in this field continues to grow, the valorization to nanotechnology‐based treatment of industrial wastewater approaches. One prominent focus of recent research is the utilization of nanomaterials, particularly carbon nanotubes (CNTs), in treating pharmaceutical wastewater, aligns with the goals of sustainable development. CNTs demonstrate potential in efficiently mineralizing pharmaceutical compounds in wastewater, offering cost‐effectiveness, ease of handling, and efficacy. Additionally, CNTs possess the capability to remediate pharmaceutical wastewater at a relatively low cost, with the advantage of being recyclable. This review provides an overview of the diverse applications of various CNTs for the removal of pharmaceutical compounds from wastewater, emphasizing the mechanisms of adsorption and degradation of these compounds using CNTs. Furthermore, it sheds light on the application of CNTs in photocatalysis as an economically viable and efficient solution.

Creating covalent bonds between Cu and C at the interface of metal/open-ended carbon nanotubes.

The unique electrical properties of carbon nanotubes (CNTs) are highly desired in many technological applications. Unfortunately, in practice, the electrical conductivity of most CNTs and their assemblies has fallen short of expectations. One reason for this poor performance is that electrical resistance develops at the interface between carbon nanomaterials and metal surfaces when traditional metal-metal type contacts are employed. Here, a method for overcoming this resistance using covalent bond formation between open-ended CNTs and Cu surfaces is investigated experimentally and supported by theoretical calculations. The open-ended CNTs are vertically oriented compared to the substrate and have carboxylic functional groups that react with aminophenyl groups (linkers) grafted on metal surfaces. The covalent bond formation, crosslinking carboxylic and amine, via amide bond formation occurs at 120 °C. The covalent bonding nature of the aminophenyl linker is demonstrated theoretically using (100), (110), and (111) Cu surfaces, and bridge-like bond formation between carbon and two adjacent Cu atoms is revealed. The electrical conductivity calculated for a single intramolecular-type junction supports covalent bond formation between Cu and CNTs. Experimentally, the robustness of the covalent bonding between vertically oriented CNTs is tested by exposing CNTs on Cu to sonication, which reveals that CNTs remain fixed to the Cu supports. Since bonding CNTs to metals was performed at low temperatures, the reported method of covalent bond formation is expected to facilitate the application of CNTs in multiple fields, including electronics.

Study on reinforcing mechanism of carbon nanotubes on tensile behavior of gangue cemented rockfill

Gangue cemented rockfill (GCR) plays a key role in underground reinforcement projects and construction waste recycling. However, the tensile performance restricted by cementitious materials limits its wider application. Hence, in this study, carbon nanotubes (CNTs) was adopted to reinforce the tensile behavior of GCR samples, since CNTs own excellent mechanical properties and promising microstructure modification in cement-based materials. The test results demonstrate that only 0.007 wt% CNTs could significantly improve tensile strength up to 47.7% and ductility failure property. Through the characterization of acoustic emission (AE), digital image correlation (DIC) and SEM techniques, we found that the microscopic improvement of CNTs could reduce the intensity of failure events, promote the distribution of strain field, and weaken the stress concentration. AE counts of single failure events dropped over 80% and cumulative energy decreased up to 76.4%. Besides, the fractal dimension of macro strain field rose by 7.45∼15.5%, which further indicates the more complex strain distribution. The established CNTs pull-out model, based on above results, further revealed that bridging CNTs provided resistance, consumed fatal work during the pull-out process and slowed down the development of microcracks. This research broadens our understanding of the improvement mechanism of CNTs on the failure mode of GCR materials, which is of great significance for CNTs application and the production of eco-friendly construction materials.

Carbon Nanotube – Synthesis, Purification and Biomedical Applications

Abstract: Carbon nanotubes (CNTs) are a relatively new class of technical materials with a variety of unique and beneficial features. CNT is a revolutionary carrier technology for both tiny and big medicinal compounds. These formulations can be surface engineered and functionalized with predefined functional groups to control their physical and biological characteristics. CNTs have proven potential for cancer therapy along with other target-oriented therapy due to their unique features, such as ease of cell viability, high drug stacking, thermal ablation, and exceptional intrinsic physical and chemical characteristics. Graphite with Sp2 bonded carbon atoms is used for the synthesis of CNT. CNTs are fabricated in a variety of ways, including arc discharge, laser ablation, chemical vapor deposition, flame synthesis, and silane solution. The present review summarises methods of preparation, types, and various applications of CNT.

Construction of polydopamine and carbon nanotube on carbon fiber surfaces to improve the mechanical properties of CF/PLA composite

Polydopamine (PDA) and carbon nanotubes (CNT) were successively incorporated onto carbon fiber (CF) to enhance surface activity. The impact of PDA and CNT on wettability and mechanical properties of the resulting composites were revealed. Fiber reinforced polylactic acid (PLA) composites were prepared. The results indicated an improved wettability for PDA-CNT modified fibers. Simultaneously, the tensile and bending curves showed brittle and plastic fracture, respectively. Mechanical properties of CF-PDA-CNT/PLA composite significantly outperformed those of CF/PLA composite. The bridging effect of PDA on the CF surface allowed for a tight bond with the matrix PLA, and provided effective load transfer between the matrix and fibers. The application of PDA and CNT on surface modification provides a novel approach for the study of fiber modification.

Polyolefin-derived substrate-grown carbon nanotubes as binder-free electrode for hydrogen evolution in alkaline media

Switching from a linear mode of waste management to a circular loop by transforming plastic waste into carbon nanotubes (CNTs) is a promising approach to current plastic waste treatment. One of the many applications of CNTs is its use for electrocatalytic water splitting for hydrogen evolution. Existing methods of CNTs-based hydrogen evolution reaction (HER) electrode fabrication involve additives like polymeric binders and additional steps to improve CNT dispersion, which are detrimental to the CNT structure and properties. The in-situ fabrication approach can potentially be a one-pot solution to HER electrode synthesis. In this study, polyolefins pyrolysis gas and a Co:Ni:Mg catalyst were used to fabricate binder-free CNTs-based electrodes on different substrates for HER. The study assessed CNT quality on conductive carbon paper, semiconductive silicon, and dielectric glass substrates, evaluating their HER performance in 1 M KOH. A mixture of hollow-core, bamboo-like, and cup-stacked arrangement nanotubes were synthesized on the substrates, with CNTs on glass and carbon paper substrates possessing better graphitization than CNTs grown on silicon. This is in agreement with HER performance, whereby the as-prepared electrodes required overpotentials of 267 mV, 241 mV, and 216 mV for silicon, glass, and carbon paper, respectively, to achieve 10 mA/cm2. Despite being poorly conductive, the glass substrate electrode achieved a lower overpotential than the silicon electrode. Additionally, the as-prepared silicon electrode faced a delamination issue likely attributed to the lower surface energy of the silicon substrate surface, demonstrating the weaker adhesion between the CNTs and silicon surface. The proposed approach thus showed that the in-situ fabricated electrodes performed better than separately synthesized CNTs prepared into electrodes by 27.4% and 14.2% for carbon paper and glass substrates, respectively. The improved performance of the as-prepared, binder-free electrodes can be linked to the lower charge-transfer resistance and reduced contact resistance between the CNTs and substrate.

Synthesis and modification of carbon nanotubes

Carbon nanotubes (CNTs) are mono-dimensional carbon nanomaterials with remarkable properties. Since their discovery by Iijima, they have been found to exhibit remarkable properties in mechanical, physical, and chemical fields. However, due to their harsh synthesis conditions and limited inherent properties, the large-scale application of CNTs is challenging. With the aim of providing a reference for further research and development of carbon nanotubes, this review summarizes the currently reported methods for synthesizing carbon nanotubes, focusing on the cost-effective arc-discharge method and chemical vapor deposition (CVD) which produce high-quality carbon nanotubes with stable performance. In addition, two different directions of CNT modifications are presented, namely, CNT filling technology and CNT solubility modification. Among them, the CNT filling technology can use CNTs as templates for nanodevice fabrication and test tubes for microscopic reactions. Meanwhile, solubility modification of CNTs is the key strategy to overcome its inherent limitations and expand their application fields.

Structure Design, Surface Modification, and Application of CNT Microwave‐Absorbing Composites

AbstractElectromagnetic (EM) contamination has now become a non‐negligible problem. To solve the EM contamination problem, it is imperative to develop high‐efficiency absorption materials with thin thickness, light weight, strong absorption properties, and broad absorption bands. Carbon nanotubes (CNTs) have a special helical structure and chirality, which will lead to special EM effects and therefore can absorb EM microwaves through magnetic polarization attenuation such as hysteresis loss, domain wall resonance, and aftereffect loss. Moreover, they have the characteristics of light weight, good compatibility, wide absorption frequency band, and high electrical loss angle tangent. In this paper, the different structures of CNT microwave‐absorbing composites are reviewed and the effects of the composite structures on the microwave‐absorbing properties are systematically discussed. The methods and mechanisms of surface modification of CNT absorber composites and the effects of modification on the absorber properties are summarized in detail. The progress of two specific CNT microwave‐absorbing composites, namely flexible and high‐temperature microwave‐absorbing composites, is briefly described. The shortcomings and challenges in the application of CNT microwave‐absorbing composites are described and future research directions for CNT microwave‐absorbing composites are explored.

Enhancing cementitious grouting performance through carbon nanotube-coated fly ash incorporation

Cementitious composites reinforced with carbon nanotubes (CNTs) offer notable benefits compared to conventional cement-based materials in terms of durability and strength. Despite these advantages, the widespread implementation of CNTs in cement-based grouting engineering has not been carried out due to the limitations of dispersion issues. In order to facilitate the progression of carbon nanotubes (CNTs) from laboratory experiments to engineering applications, we proposed a method of using amino-functionalised functional groups to coat CNTs on the fly ash (FA) particles’ surfaces to assist the dispersion and prepare cost-effective, low-carbon emission, energy consumption-saving and high-performance cementitious slurry. The experimental results exhibit that compared with plain cement-based grouting materials, incorporating 0.023 wt% CNTs and 14.3 wt% FA can reinforce the compressive and tensile strength by 14.2–25.8% and improve the workability by about 21.0%. The application of coated CNTs induces nucleation and pore-infilling effects within the interfacial transition zone (ITZ) of the cementitious composites. This action leads to a reduction in ITZ width and a decrease in crack occurrence within the ITZ. Consequently, these effects contribute to an augmentation in the consolidation strength of the slurry. Acoustic emission and fracture surface fractal analysis further reveal that incorporating CNTs enhances the resist-loading ability of the cement matrix by increasing its energy absorption capability. The innovative coating method reported in this work is expected to facilitate the future application of CNTs in practical grouting engineering.

Experimental study on flame spread over PMMA composites with addition of carbon nanotubes

Experiments on flame spread over cantilevered polymethyl methacrylate (PMMA) composites with addition carbon nanotubes (CNTs) were conducted and flame spread behaviors was analyzed. Results show that the two flame regions, surface flame and dripping flame, are distinguished because of the enhanced viscosity of the molten materials with the addition of CNTs. The combustion-supporting effect from the dripping flame promotes flame spread, the flame height and the flame spread rate are increased with CNTs. There is a power-law relationship between the whole flame height and the dripping flame height, H∝H20.682. The heat transfer analysis is also conducted based on the divisions of flame region. As the content of CNTs increases, the heat flux from surface flame is almost constant, but for dripping flame, it is twice as much as pure PMMA at 2.5% CNTs and the contribution in heat flux of dripping flame reaches 40%. The heat flux from dripping flame has important effects on sustaining flame spread and the increasing flame spread rate is mainly attributed to the enhancement of the heat feedback of dripping flame. These results are contrary to the effects of the flame retardancy by CNTs, which means the application of CNTs as flame retardants in polymers needs to consider the fire scenarios.

Recent advances of carbon nanotubes in perovskite solar cells

AbstractPerovskite solar cells (PSCs) have exhibited tremendous potential in photovoltaic fields owing to their appreciable performance and simple fabrication. Nevertheless, device performances are still required to be further improved before commercial applications. As one‐dimensional materials, carbon nanotubes (CNTs) have been utilized to regulate stability and efficiency of PSCs because of their excellent chemical stability, flexibility, as well as tunable optical and electrical characteristics. In this review, we comprehensively summarize various functions of CNTs in PSCs, such as transparent electrodes, hole/electron‐transport layers, counter electrodes, perovskite additives, and interlayers. Additionally, applications of CNTs toward the advancement of flexible and semitransparent PSCs are provided. Finally, we preview the challenges and research interests of using CNTs in high‐efficiency and stable perovskite devices.

Carbon Nanomaterials from Polyolefin Waste: Effective Catalysts for Quinoline Degradation through Catalytic Wet Peroxide Oxidation

Quinoline (QN) is highly toxic and carcinogenic and has been detected in soil, groundwater, and biological tissues. Advanced oxidation processes (AOPs) have shown promise to address its degradation in wastewater treatment, with catalytic wet peroxide oxidation (CWPO) being highlighted due to its cost-effectiveness and mild operation. However, developing active and inexpensive catalysts is crucial for CWPO’s effectiveness. Another pressing issue is the accumulation of mixed, dirty plastic solid waste (PSW), particularly polyolefins used in packaging. Although recycling rates have increased, much plastic packaging remains in landfills. However, polyolefins can be converted into carbon-based nanostructured materials (CNMs), such as carbon nanotubes (CNTs), through chemical vapor deposition (CVD) using PSW as a carbon precursor. While many studies focus on CNT preparation, their application is often overlooked. In this context, this work proposes the preparation of CNMs, particularly CNTs, through CVD using a single-stage pyrolysis reactor. Polyolefins (LDPE, HDPE, and PP), both individually and in a mixture simulating PSW, were used as carbon sources. Given a sufficiently high temperature, the desired CNT architecture was successfully synthesized regardless of the starting polymer. These CNMs were then tested as catalysts for CWPO in simulated wastewater containing QN. The results showed a rapid degradation of QN (30–120 min) and high removals of total organic carbon (TOC) and aromatic compounds (75% and >90%, respectively), demonstrating the applicability of PSW-derived CNTs in the CWPO process for QN abatement.

(Invited) Bio-Applications of Carbon Nanotubes for NIR Imaging Probes and Guided Bone Regeneration Membranes

Single-walled carbon nanotubes (CNTs) have been expected for biological and medical applications because of their unique optical and chemical properties. One of the promising applications is imaging probes because CNTs show fluorescence in the near-infrared (NIR) region, which is highly transparent for biomaterials. We have reported the synthesis method of the epoxide-type oxygen-doped CNTs (Ep-CNTs) and their application as a near-infrared fluorescent probe [1-3]. Treated (6, 5) nanotubes show photoluminescence at ~1280 nm, which corresponds to the most transparent regions for biomaterials [1]. Immunoassay and fluorescence vascular angiography of mice were demonstrated by using the produced Ep-CNTs as infrared fluorescent labels [1,3] and imaging agents [1,2], respectively. From a practical point of view, the biodistributions of the Ep-CNTs imaging probe after administration to mice were investigated in detail [2]. In addition, the biological responses of mice following administration, which are relevant to safety, were also introduced [2].More recently, we found that CNTs exhibit high compatibility with bone tissue [4]. The guided bone regeneration (GBR) technique is commonly applied to reconstruct alveolar bone and treat peri-implant bone defects. It was found that CNT-based membrane for GBR exhibits high strength to provide a space for bone formation and provide cellular shielding to induce osteogenesis.In this meeting, we will report above biological and medical applications of CNTs in detail.1. Y. Iizumi, M. Yudasaka, J. Kim, H. Sakakita, T. Takeuchi, T. Okazaki, Oxygen-doped carbon nanotubes for near-infrared fluorescent labels and imaging probes, Sci. Rep., 8, 6272 (2018).2. T. Takeuchi, Y. Iizumi, M. Yudasaka, S. K. Kondoh, T. Okazaki, Characterization and biodistribution analysis of oxygen-doped single-walled carbon nanotubes used as in vivo fluorescence imaging probes, Bioconjugate Chem., 30, 1323−1330 (2019). (Cover Article)3. K. Kojima, Y. Iizumi, M. Zhang, T. Okazaki, Streptavidin-conjugated oxygen-doped single-walled carbon nanotubes as near-infrared labels for immunoassays, Langmuir, 38, 1509-1513 (2022).4. Y. Xu, E. Hirata, Y. Iizumi, N. Ushijima, K. Kubota, S. Kimura, Y. Maeda, T. Okazaki, A. Yokoyama, Single-walled Carbon Nanotube Membranes Accelerate Active Osteogenesis in Bone Defects: Potential of Guided Bone Regeneration Membranes, ACS Biomater. Sci. Eng., 8, 1667-1675 (2022).

(Digital Presentation) Preparation and Characterization of PMMA-SWCNT Nanocomposites

Carbon nanotubes (CNTs) exhibit unique properties such as high tensile strength, excellent electrical conductivity, and resistance to corrosion. Unfortunately, macroscopic objects from these nanostructures do not perform equally well because the individual nanotubes do not transfer electrical charge, phonons, or stress between them sufficiently well. One possible solution to improve the properties of macroscopic ensembles from nanocarbon is to manufacture the composites with other materials like polymers, ceramics, or metals. This connection is usually beneficial. However, the properties depend strongly on the integration degree of the two compounds. For example, nanocomposites with polymers have improved mechanical (Poly(methyl methacrylate), PMMA) or electrical (in the cause of conductive polymers) properties. Many ways lead to PMMA-CNTs, but the most popular are coating (dip-coating, spin-coating, spray-coating) and dispersion methods.One of the potential applications of these composites is as a membrane for the purification of wastewater from organic residues. Unfortunately, industrial growth in the last century has caused a reduction in the availability of pure water, so the abovementioned application of CNTs would be beneficial. However, the main problem with pristine carbon nanotube films is their structural integrity. The addition of polymer molecules could overcome this problem and lead to a new effective method of removing impurities.The commercial single-walled carbon nanotubes (TuballTM) were used to create nanocomposites with PMMA using either dip-coating or dispersion method. Scanning Electron Microscopy (SEM), Raman spectroscopy, Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy, and mechanical testing were used to analyze composites. The nanocomposites were used to remove aromatic organic compounds dissolved in water. For model substances methyl orange, methylene blue, and fluorescein were chosen. UV-VIS spectroscopy was used to gauge the concentration of organic compounds before/after the filtration of the aqueous solution dissolved therein. The best results were for SWCNTs and PMMA-SWCNTs membranes as they removed more than 99% of chosen water impurities.

Electronic structures and dielectric function of (5, 5) CNT-C2H4O system: A first-principles study on the detection capability of CNT for gas sensing applications.

Carbon nanotubes (CNTs) are known to have a wide range of applications in various fields of discipline. In this research, the ability of metallic armchair (5, 5) CNT to detect acetaldehyde (C2H4O) was investigated using first-principles density functional theory (DFT) as implemented in Quantum ESPRESSO with the Generalized Gradient Approximation (GGA). Accordingly, it was found that C2H4O preserved the metallic behavior of the CNT. However, some bands are found to have overlapped in both the valence and conduction regions of the electronic structures of the resulting system that are mainly caused by the p orbitals of the oxygen and carbon atoms of the compound. These are further confirmed by the projected density of states (pDOS). Moreover, optical transitions are observed in both the real and imaginary parts of the dielectric function caused by the interband transitions between the Van Hove singularities of the electronic structures. In all circumstances, this research has provided more insights into the potential gas sensing applications of metallic CNTs.

Fabrication of carbon nanotube components using 3D printing: Review

One of the most recognizable innovations in nanotechnology is the Carbon Nanotube (CNT). Due to their promising applications, CNTs have been the focus of many studies during the last two decades. CNTs are nano-sized, very flexible, resistant to corrosion, electrically and thermally conductive, biocompatible, and can be customized and functionalized. By building up materials layer by layer, Additive Manufacturing (AM) is a useful method for fabricating nanocomposites in complicated geometries. It has recently come to light that AM techniques are promising contenders for synthesizing CNT applications with varied functions. Extrusion-based 3D printing techniques (such as Fused Deposition Modeling (FDM), inkjet printing, and Direct Ink Writing (DIW)) show great potential for fabricating CNT applications such as sensors, batteries, electrodes, supercapacitors, and scaffolds. This article provides an overview of the latest literature on 3D-printed CNT applications using various AM processes.