Browse Topic: Carbon nanotubes

Items (264)
ABSTRACT Additions of both carbon fiber (CF) and carbon nano-tubes (CNTs) as reinforcements to polyurea (PUr) based adhesives are computationally investigated. Both CF and CNTs show an increase in stiffness. The effect of CF reinforcements on the PUr is more pronounced than the CNT’s but this due to CNT loading being dramatically lower. On percent basis the CNT effect on strength was greater than the CF. Increasing hard segment content of PUr also had a positive effect on the joint strength, but a negative effect on the shear joint displacement. Finally the addition of CF reinforcements moved the performance of a PUr formulation from a Group IV adhesive into the Group III category. This paper illustrates the potential for commonly available reinforcements to be used to tailor the strength elongation characteristic of a PUr adhesive system. Citation: Demetrios A. Tzelepis, Robert Hart, “Optimization of Nano-Enhanced Elastomeric Adhesives Through Combined Experimental and Computational
Tzelepis, Demetrios A.Hart, Robert
A flexible and stretchable cell has been developed for wearable electronic devices that require a reliable and efficient energy source that can easily be integrated into the human body. Conductive material consisting of carbon nanotubes, crosslinked polymers, and enzymes joined by stretchable connectors, are directly printed onto the material through screenprinting
Researchers have shown that twisted carbon nanotubes can store three times more energy per unit mass than advanced lithium-ion batteries. The finding may advance carbon nanotubes as a promising solution for storing energy in devices that need to be lightweight, compact, and safe, such as medical implants and sensors
The present work deals with the effects of nano-additives on ternary blend biodiesel fuel added in diesel engine. The ternary blend comprises of mustard oil biodiesel and rice bran oil biodiesel, synthesized by means of transesterification and diesel. Nano-additives used in the current study include carbon nanotubes (CNT) and MgO/MgAl2O4 spinel, which were added in a suitable concentration to the biodiesel. CNTs were procured from the market and MgO/MgAl2O4 spinel was prepared by co-precipitation via ball milling process. The nano-additives were characterized by means of FTIR (Fourier transform infrared spectroscopy), AFM (atomic force microscopy), and DSC (differential scanning calorimetry) analysis. Biodiesel blend samples were prepared such as B20 (20% biodiesel + 80% diesel), B20 + CNT (1000 PPM), B20+MgO/MgAl2O4 spinel (1000 PPM), and B20+CNT+MgO/MgAl2O4 spinel (1000 PPM) were tested against diesel fuel. The maximum increase in brake thermal efficiency (BTE), oxides of nitrogen
Jeyakumar, NagarajanDhinesh, BalasubramanianPapla Venugopal, Inbanaathan
This research explores the experimental analysis of titanium alloy using an innovative approach involving a 2–7% carbon nanotube (CNT)-infused cubic boron nitride (CBN) grinding wheel. Employing a full-factorial design, the study systematically investigates the interactions among varied wheel speed, workpiece feed rate, and depth of cut, revealing compelling insights. The integration of CNTs in the CBN grinding wheel enhances the machining performance of titanium alloy, known for its high strength and challenging machinability. The experiment varies CNT infusion levels to assess their impact on material removal rate (MRR) and surface finish. Significantly, MRR is influenced by CNT content, with 5% and above demonstrating optimal performance. The 7% CNT-CBN wheel exhibits a remarkable 61% improvement in MRR over the conventional CBN wheel. Interaction studies highlight the pivotal role of depth of cut, indicating that slower speeds and feeds, combined with increased depth of cut
Stephen, Deborah SerenadeSethuramalingam, Prabhu
Membranes of vertically aligned carbon nanotubes (VaCNT) can be used to clean or desalinate water at high flow rate and low pressure. Recently, researchers of Karlsruhe Institute of Technology (KIT) and partners carried out steroid hormone adsorption experiments to study the interplay of forces in the small pores. They found that VaCNT of specific pore geometry and pore surface structure are suited for use as highly selective membranes. The research was published in Nature Communications
Innovators at NASA’s Glenn Research Center have made several breakthroughs in treating hexagonal boron nitride (hBN) nanomaterials, improving their properties to supplant carbon nanotubes in many applications. These inventors have greatly enhanced the processes of intercalation and exfoliation. Both processes are crucial in creating usable nanomaterials and tailoring them for specific engineered applications
In research that may lead to advancements in the design of next-generation airplane and spacecraft, MIT engineers used carbon nanotubes to prevent cracking in multilayered composites. Massachusetts Institute of Technology, Cambridge, MA To save on fuel and reduce aircraft emissions, engineers are looking to build lighter, stronger airplanes out of advanced composites. These engineered materials are made from high-performance fibers that are embedded in polymer sheets. The sheets can be stacked and pressed into one multilayered material and made into extremely lightweight and durable structures. But composite materials have one main vulnerability: the space between layers, which is typically filled with polymer “glue” to bond the layers together. In the event of an impact or strike, cracks can easily spread between layers and weaken the material, even though there may be no visible damage to the layers themselves. Over time, as these hidden cracks spread between layers, the composite
A team of inventors from NASA Langley and NASA Ames have created a new type of carbon fiber polymer composite that has a high thermal conductivity. This was achieved by incorporating Pyrolytic Graphite Sheets (PGSs) and Carbon Nanotubes (CNTs), which enhance the material’s ability to transfer heat when compared to typical carbon fiber composites
The aerospace industry's unceasing quest for lightweight materials with exceptional mechanical properties has led to groundbreaking advancements in material technology. Historically, aluminum alloys and their composites have held the throne in aerospace applications owing to their remarkable strength-to-weight ratio. However, recent developments have catapulted magnesium and its alloys into the spotlight. Magnesium possesses two-thirds of aluminum's density, making it a tantalizing option for applications with regard to weight-sensitive aerospace components. To further enhance magnesium's mechanical properties, researchers have delved into the realm of metal matrix composites (MMCs), using reinforcements such as Alumina, Silicon carbide, Boron carbide and Titanium carbide. However, meager information is available as regards to use of Multi-Walled Carbon Nanotubes (MWCNTs) as a reinforcement in magnesium based MMCs although, CNTs exhibit excellent stiffness coupled with very low density
Mukunda, SandeepBoppana, Satish BabuChinnakurli Suryanarayana, RameshT, AravindaKhan, Saleem
The latest developments in composite materials are anticipated by green engineering. Materials must be eco-friendly, recyclable, biodegradable, and easy to decompose. Researchers are interested in utilizing natural fibres, fillers, and synthetic active ingredients. Natural fiber-polymer composites can specify certain mechanical properties but are hydrophilic and weak, so they rarely meet the needed thermal properties. Composite material selection depends on the application and the superior properties of the fibre/filler: banana fibre (BF), ice husk (RH) and multi-walled carbon nanotubes (MWCNT). In this research article, a brief discussion of the heat transfer mechanism of composites and the development of energy conduction equation are performed for hybrid natural polymer composite. The maximum thermal conductivity observed for 10BF/10RH/1MWCNT wt.% composite is 0.2694 W/mK. From ANSYS numerical simulation, the temperature distribution along the composite wall temperatures T1 to T8
Senthilkumar, N.Ramu, S.Deepanraj, B.
Surface integrity is an important factor in the effective functioning of a component. For this reason, the surface finish is given as meticulous attention as possible, while quality checks are rigorous. The process parameters affecting surface roughness are carefully controlled, with many preventive measures enforced to avoid deviation from the tolerance limits. Surface finish is an important part of the load-bearing properties of a surface as the asperities on its surface first come into contact with the mating surfaces. On contact, the asperities are flattened, and there is debris formation. These asperities are critical in joint replacements where Titanium is a material of choice, as the debris can react with bones and even cause necrosis of bone. The surface finish of Titanium is important as the asperities can function as points of stress when subjected to loads. Stress concentrators are detrimental to a material’s life; therefore, a part’s surface finish becomes critical. This
Stephen, Deborah SerenadeV, PraveenaAv, RamanathanS, Sujith
Researchers in the Lyding Group at the University of Illinois Urbana-Champaign have discovered an efficient, sustainable method for 3D-printing single-walled carbon nanotube films, a versatile, durable material that can transform how we explore space, engineer aircraft, and wear electronic technology
Muscle contraction hardening is not only essential for enhancing strength but also enables rapid reactions in living organisms. Taking inspiration from nature, the team of researchers at Queen Mary’s School of Engineering and Materials Science has successfully created an artificial muscle that seamlessly transitions between soft and hard states while also possessing the remarkable ability to sense forces and deformations
Innovative carbon nanotube (CNT) electrothermal heating technology for ice protection systems is one of the alternatives under development that shall contribute to more efficient and sustainable aircraft. CNT heater technology allows for more rapid heat up rates over legacy metallic electrothermal heaters that utilize resistance wires or metallic foils. This more rapid heat up rate can lead to more energy efficient electrothermal ice protection system designs and is being studied to determine how much the rapid heat up properties of CNT can lead to a minimization of residual ice build-up aft of the heated area. Due to the inherent redundancy of CNT material used, leads to a very robust and damage tolerant heating element. To mature this technology to prepare to implement CNT on an in-service aircraft platform, a multi-staged flight testing effort to prove out the technology on an actual aircraft and in a relevant environment is mandatory. Recently a major milestone was achieved after
Hein, BrandonBotura, GaldemirHamman, MatthewSlane, Casey
Mechanical engineering researchers at Michigan Technological University have created a way to make a 3D-printable nanocomposite polymeric ink that uses carbon nanotubes (CNTs) — known for their high tensile strength and lightness. This revolutionary ink could replace epoxies
Researchers at Lawrence Livermore National Laboratory (LLNL) are scaling up the production of vertically aligned single-walled carbon nanotubes (SWCNT) that could revolutionize diverse commercial products ranging from rechargeable batteries, automotive parts and sporting goods to boat hulls and water filters. The research appears in the journal Carbon
Electro-hydraulic actuators, a type of soft actuators, can provide soft-touch vibrations due to their structural characteristics, but some problems need to be improved to apply them to vehicles. That is, it is necessary to increase excitation force, expand frequency band, lower driving voltage, and increase durability. This research aims to design a new type based on electro-hydraulic actuator and improve problems with its performance to develop a product that generates emotional vibration in vehicles. First, a new mechanism and design of an electro-hydraulic actuator called a PVC-gel film actuator are proposed. This actuator uses PVC-gel as a film which covers a dielectric liquid and uses carbon nanotube as a cathode material. In addition, a method of manufacturing an actuator with improved performance has been proposed by creating and testing prototypes with different sizes and material properties. It has been verified that the proposed actuator improves excitation force, frequency
Chang, Kyoung-JinKyung, Ki-UkKim, HyunwooHong, SangjinPark, Dong Chul
Using ammonia as fuel in retrofitted large marine vessels or heavy-duty vehicles has the potential to reduce CO2 emissions. However, ammonia is hard to burn in an internal combustion engine (ICE) due to its poor combustion properties, i.e. having high autoignition temperatures and low flame speeds. This results in the need for a highly reactive secondary fuel or an improved ignition system for achieving complete and stable combustion. This study investigates a radical technology for the ignition of a fuel-air mixture using carbon nanotubes. The technology consists of injecting a mixture of multi-walled carbon nanotubes and ferrocene (CNT-Fe) into a fuel-air mixture and subjecting the particles to a bright flash of light. Due to the photochemical properties of CNT-Fe particles, the absorbed light initiates ignition. The burning particles thereby ignite the gas mixture at multiple points in the chamber, resulting in a flame front propagating faster compared to when using conventional
Bjorgen, Karl Oskar PiresSaanum, IngeBratsberg, StianJørgensen, PatrickLovas, TereseEmberson, David
This paper will focus on the root facture problem of carbon fibre reinforced polymers (CFRP) material of aircraft winglets through ABAQUS simulation analysis regarding the aircraft takeoff and landing from high altitude at the constant and low-temperature experimental analysis and topography analysis. The innovative purpose of this paper is to identify the critical failure stress of the cantilever bending of unidirectional and orthogonal, embedding carbon nanotube reinforcement, and exploring the embedded carbon nanotube regarding the enhancement effect of CFRP aircraft winglet. First of all, the analysis of the force state of the aircraft winglet, the unidirectional and orthogonal CFRP aircraft winglet at normal temperature, and low- temperature cycling is established based on the principle of classic laminates and statics. The wing cantilever bending critical failure stress mechanics model provides a theoretical basis for the influence of low- temperature cycles on aircraft winglets
Miah, Md Helal
The composite sandwich structure has been in use in space applications particularly for the satellite body because of its high strength to weight ratio coupled with excellent compressibility strength. In particular, there has been tremendous demand for honeycomb sandwich structures for satellite application in recent years. Currently, a major problem needs to be addressed concerning reflections from satellite structures which leads to capturing in-accurate data of celestial bodies by ground-based astronomy. In the light of the above, this paper focuses on the development of novel optical black coating on Carbon fiber reinforced composite sandwich structures with aluminum honeycomb core. A thin layer of Multi-Walled Carbon Nanotubes black coating was developed on the surfaces of Carbon fiber reinforced composite laminate of the sandwich structure using the Chemical Vapour Deposition technique, to provide a low reflective surface. A three-point bending test is performed for evaluating
J, SudharshanChaurasia, P HarshSURYANARAYANA, RAMESH
As an excellent nanoscale material, carbon nanotubes (CNTs) play a very important role in improving the batteries of new energy vehicles. The micro-scale combustion flame synthesis method is a promising method for preparing carbon nanotubes. To explore the optimal growth condition of carbon nanotubes under micro-scale combustion, the detailed mechanism of methanol C3 (114 species, 1999 reactions) was reduced based on whole-species sensitivity analysis, then a suitable model of methanol combustion was established by using Fluent software coupling with simplified mechanism (16 species, 65 reactions) of methanol. The model was used for the numerical simulation of micro-scale coaxial diffusion combustion of methanol, and then it was verified by the experimental results of micro-scale combustion of methanol. They were analyzed that the flame temperature field and important intermediate product concentration including the Carbon monoxide (CO), oxhydryl (OH), and aldehyde (HCO) under
Zhang, PengNi, JiminShi, Xiuyong
This research involves the study of the different properties of aluminum alloy AA 2024 in the presence of carbon nanotubes (CNTs) and Silicon (Si) nanoparticles. Structural morphology, elemental composition, mechanical properties (density, tensile strength, elongation, and hardness), and tribological properties (wear rate and coefficient of friction) of AA 2024 in the presence of CNTs, Si, and its combinations at various proportions were evaluated using a Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Analyzer (EDX), Universal Testing Machine (UTM), Model HMV-2T Vickers hardness test machine, and pin-on-disk friction-and-wear test rig. The Hybrid Metal Matrix Composite (HMMC) material is prepared by a two-stage stir casting method. It was found that the density of the AA 2024 + 4%CNT + 2%Si is 2.22 g/cm3, ultimate tensile strength is 308 N/mm2, elongation is 15.5%, and Vickers hardness is 187.5 Vickers Hardness Number (VHN). The pin on the disk machine is used to evaluate
Muniyappan, M.Iyandurai, Natesan
Researchers report the design and fabrication of single-wall carbon nanotube thermoelectric devices on flexible polyimide substrates as a basis for wearable energy converters
NASA Marshall Space Flight Center developed designs for two micro-electromechanical systems (MEMS) motion and position sensors: a single-axis accelerometer and a gyroscope. The designs leverage a highly aligned multi-wall carbon nanotube (MWCNT) tape with a P(VDF-TrFE) matrix that is mechanically robust and has excellent piezoelectric properties as the sensing and actuating element
This paper presents the numerical analysis of four different nanoparticles namely Aluminium oxide (Al2O3), Silver nitrate (AgNO3), (Fe2O3) and Carbon nanotubes (CNT) mixed with mixture of water and ethylene glycol as fluid medium in an automobile radiator using louvered fin arrangement using forced convection technique under turbulent flow regime. The flow rate of coolant varied from 2 l/min to 5 l/min, while the velocity of air and temperature are constant. The use of nano fluids enhanced the rate of heat transfer of in the radiator as compared to water and ethylene glycol binary mixture as cooling medium. From the numerical analysis, it is found that CNT-H2O nano fluids exhibited better heat transfer characteristics as compared to Al2O3, Fe2O3 and AgNO3 nano particle in the base fluid. Furthermore, the increase in concentration of nanoparticles with the base fluid increases the convective heat transfer coefficient and Nusselt number (Nu). Also, it is found that the rate of increase
Sathyamurthy, RavishankarChandran, PrasadPrakash, NKaliappan, Vishnu Kumar
In this research helical Carbon Nanotubes (CNTs) with various weight percentages as an additional reinforcement were used. The objective was to investigate the effectiveness of helical geometries of the CNTs to form interlocking mechanisms with the resin and the traditional microfiber reinforcements to improve the overall performance of the composite structures and assemblies. In this study, ASTM D2344/2344M-16 is used to study the short beam strength of the laminated nanocomposites and evaluate the benefit of the mechanically interlocked helical CNTs reinforcement. Overall, three sets of composite laminates (i.e., with neat epoxy, and with two different wt% of Helical CNTs reinforced epoxy) were fabricated per ASTM standard D2344/2344M-16. Adequate test specimens were prepared and then they were tested per ASTM standard. The test results were analyzed and evaluated to determine the effects of helical CNTs on short beam strength of the laminated nanocomposites
Sritharan, RamananAskari, Davood
The main objective of the RadCNT program was the characterization of fundamental mechanisms and charge transport phenomena governing the interactions between ionizing and non-ionizing radiation with carbon-based (nanotube and graphene) field-effect transistors (FETs) devices and integrated circuits (ICs). This effort was supported through the fabrication of aligned single-walled carbon nanotubes (SWCNT) FETs at the University of Southern California’s (USC) Nanotechnology Research Laboratory and through a collaboration with the Naval Research Laboratories (NRL) for radiation testing and expertise in radiation effects characterization
Most composite assemblies and structures generally fail due to weak interlaminar properties and poor performance of their bonded joints that are assembled together with an adhesive layer. Adhesive failure and cohesive failure are among the most commonly observed failure modes in composite bonded joint assemblies. These failure modes occur due to the lack of reinforcement within the adhesive layer in transverse direction. In addition, the laminated composites fail due to the same reason that is the lack of reinforcement through the thickness direction between the laminae. The overall performance of any composite structures and assemblies largely depends on the interlaminar properties and the performance of its bonded joints. Various techniques and processes were developed in recent years to improve mechanical performance of the composite structures and assemblies, one of which includes the use of nanoscale reinforcements in between the laminae and within the adhesive layer. However
Sritharan, RamananAskari, Davood
Carbon nanotubes (CNTs) show promise for multifunctional materials for a range of applications due to their outstanding combination of mechanical, electrical, and thermal properties. These promising mechanical properties, however, have not translated well to CNT nanocomposites fabricated by conventional methods due to the weak load transfer between tubes or tube bundles
Carbon nanotubes are supermaterials that can be stronger than steel and more conductive than copper. The reason they're not in every application from batteries to tires is that these properties only show up in the tiniest nanotubes, which are extremely expensive. A new process was developed that can make these materials from carbon dioxide drawn from the air, in a way that is much less expensive than other methods. These materials could impact how emissions can be used in future technology
Items per page:
1 – 50 of 264