Coated Carbon Nanotubes Research Articles

Creating high-performance transistors by coating carbon nanotube arrays

Creating high-performance transistors by coating carbon nanotube arrays

Atomically Dispersed Transition Metal Catalysts for Electrochemical Chlorine Evolution Reaction

Chlorine evolution reaction (CER) is a crucial anodic reaction in the chlor–alkali process. For 50 years, dimensionally stable anode (DSA) has been extensively used for CER. However, the DSA requires about 30 at% of precious metals, such as iridium and ruthenium, and also catalyzes oxygen evolution reaction as a parasitic reaction, invoking the cost and selectivity issues, respectively. In this work, we have synthesized atomically dispersed non-precious metal (M; M = Fe, Co, Ni, and Cu)-based CER catalysts to unravel their CER catalytic trends. The catalysts were synthesized by coating carbon nanotube (CNT) with polyaniline layers, adsorption of a metal precursor, silica layer overcoating, thermal annealing, followed by silica layer etching. The resulting M1/aniCNT catalysts showed over 90% CER selectivity. Among the catalysts, Ni1/aniCNT exhibited the best CER activity, surpassing that of DSA. The high CER activity of Ni1/aniCNT is attributed to the asymmetric Ni–N3 structure with Ni1+ oxidation state. This work highlights the dependency of activity on the structure of atomically dispersed catalysts and broadens the range of CER catalysts.

Carbon Nanomaterial Enabled Ultra High Conductivity Cu Composites for Advanced Conductors

Growing demand for electrical energy and increasing need for high power grid systems necessitates development of new conductors for enhanced electrical and thermal conductivity. The power losses associated with the electrical resistance of Cu adversely impact the efficiency and performance of all electric devices. Ballistic electrical transport in carbon nanotubes (CNTs) is expected to improve the conductivity of the Cu matrix with additional CNT-enabled benefits that can enable low-weight, flexibility, and better thermal management. By using scalable, cost-effective, and commercially viable processing methods, we demonstrate a novel technological platform to produce high-performance conductors that incorporates CNTs into the Cu matrix ― ultra-conductive metal composites (UCC), which promise significant technological and economic impact in all energy sectors, ranging from electrical vehicles to power grid. Our approach, which combines materials synthesis, characterization, and first-principles modeling, enables an efficient and systematic exploration of the multidimensional complex materials parameter space of Cu-CNT composites with dopants and identifies the key individual structural and interfacial components that govern the electronic transport properties of the UCC composites. Our experimental technology platform is concentrated on Cu tapes and involves processes from production of stable CNT dispersions, electrospinning techniques to deposit shear induced aligned CNT coatings along the direction of the current flow, post thermal treatment procedures, and homogeneous deposition of metal overlayers onto CNT coated tapes. Here, we demonstrate that the prototype UCC composites exhibit improved electrical conductivity (by > 5%), higher current carrying capacity (> 10%), and higher mechanical strength (> 10%) than the reference pure Cu counterparts.

TiO2 nanoparticle coated carbon nanotube sponge with high sunlight absorption and good hydrophilicity for efficient interfacial solar-powered vapor generation

Solar-powered interfacial vapor generation is considered a promising sustainable energy technology. We use porous TiO2 nanoparticle coated carbon nanotube sponges (CNTS@TiO2) as sunlight absorbers to study solar-powered interfacial vapor generation due to the extremely strong sunlight absorption of CNTs and TiO2. The highly porous structures have great benefits to water transport in the sunlight absorbers. The formation of TiO2 on the sidewalls of CNTs improves the hydrophilicity of the light absorber and wettability of water on the sidewalls of CNTs. The water can rapidly infiltrate the porous CNTS@TiO2 composites. Additionally, the multiple internal reflections in “TiO2 forest” greatly reduce the diffused reflection and thus enhance sunlight absorption. The CNTS@TiO2 composites exhibit high sunlight absorption (96.7 %). The efficient water transport and strong light absorption in the porous light absorbers significantly improved the evaporation performance. The CNTS@TiO2 composite with the rhombic TiO2 shows high water evaporation rate of 3.15 ± 0.14 kg m-2 h-1 and energy transfer efficiency of 89.5 ± 3.9 % under 1-sun radiation.

Vacuum Filtration-Coated Silver Electrodes Coupled with Stacked Conductive Multi-Walled Carbon Nanotubes/Mulberry Paper Sensing Layers for a Highly Sensitive and Wide-Range Flexible Pressure Sensor.

Flexible pressure sensors based on paper have attracted considerable attention owing to their good performance, low cost, and environmental friendliness. However, effectively expanding the detection range of paper-based sensors with high sensitivities is still a challenge. Herein, we present a paper-based resistive pressure sensor with a sandwich structure consisting of two electrodes and three sensing layers. The silver nanowires were dispersed deposited on a filter paper substrate using the vacuum filtration coating method to prepare the electrode. And the sensing layer was fabricated by coating carbon nanotubes onto a mulberry paper substrate. Waterborne polyurethane was introduced in the process of preparing the sensing layers to enhance the strength of the interface between the carbon nanotubes and the mulberry paper substrate. Therefore, the designed sensor exhibits a good sensing performance by virtue of the rational structure design and proper material selection. Specifically, the rough surfaces of the sensing layers, porous conductive network of silver nanowires on the electrodes, and the multilayer stacked structure of the sensor collaboratively increase the change in the surface contact area under a pressure load, which improves the sensitivity and extends the sensing range simultaneously. Consequently, the designed sensor exhibits a high sensitivity (up to 6.26 kPa-1), wide measurement range (1000 kPa), low detection limit (~1 Pa), and excellent stability (1000 cycles). All these advantages guarantee that the sensor has potential for applications in smart wearable devices and the Internet of Things.

Honeycomb Cell Structures Formed in Drop-Casting CNT Films for Highly Efficient Solar Absorber Applications.

This study investigates the process of using multi-walled carbon nanotube (MWCNT) coatings to enhance lamp heating temperatures for solar thermal absorption applications. The primary focus is studying the effects of the self-organized honeycomb structures of CNTs formed on silicon substrates on different cell area ratios (CARs). The drop-casting process was used to develop honeycomb-structured MWCNT-coated absorbers with varying CAR values ranging from ~60% to 17%. The optical properties were investigated within the visible (400-800 nm) and near-infrared (934-1651 nm) wavelength ranges. Although fully coated MWCNT absorbers showed the lowest reflectance, honeycomb structures with a ~17% CAR achieved high-temperature absorption. These structures maintained 8.4% reflectance at 550 nm, but their infrared reflection dramatically increased to 80.5% at 1321 nm. The solar thermal performance was assessed throughout a range of irradiance intensities, from 0.04 W/cm2 to 0.39 W/cm2. The honeycomb structure with a ~17% CAR value consistently performed better than the other structures by reaching the highest absorption temperatures (ranging from 52.5 °C to 285.5 °C) across all measured intensities. A direct correlation was observed between the reflection ratio (visible: 550 nm/infrared: 1321 nm) and the temperature absorption efficiency, where lower reflection ratios were associated with higher temperature absorption. This study highlights the significant potential for the large-scale production of cost-effective solar thermal absorbers through the application of optimized honeycomb-structured absorbers coated with MWCNTs. These contributions enhance solar energy efficiency for applications in water heating and purification, thereby promoting sustainable development.

Comparative Analysis of Single- and Poly-Crystalline Layered Cathode Materials: Determining the Superior Choice

In the field of cathode material candidates of lithium-ion batteries, there has been ongoing debate regarding which material is superior: poly-crystalline (PC) or single-crystalline (SC) cathode active materials. The PC materials are characterized by primary particles that agglomerate into secondary particles, which PCs are prone to micro-crack due to significant c-axis volumetric expansion/contraction in their lattice structure.As an alternative, the SC materials have been received attention for their physical resistance from the expansion/contraction and external pressure. However, in terms of lithium-diffusion pathway, it has been reported that SC’s structures possess certain disadvantages in lithium-ion diffusion compared to PC materials. This is attributed to the scarcity of grain boundaries and the extensive pathways of bigger primary particles in SC, which impede the efficient movement of lithium ions. Even though the comparative analysis has been needed between PC and SC above superiority, achieving an exact comparison under identical or similar conditions is challenging due to differences in particle size and surface environment, including binders and conducting materials.In this study, we standardized the size of both PC and SC particles to 10 μm to evaluate their electrochemical performance under identical environmental conditions and using a common commercial electrode composition (96:2:2, active material, carbon black, and PVDF binder) in a wet process with a 60% nickel cathode (NCM622). Consequently, in comparing PC and SC materials, the focus has been on analyzing key factors that contribute to electrode performance, specifically concerning issues of lithium-ion diffusion and the composition of materials at the electrode level that may arise. Moreover, we fabricated SC electrodes using a solvent-free dry electrode process as an alternative of better process, aimed at creating higher energy density electrodes without the addition of carbon black, but rather by employing coated carbon nanotubes (CNT) on the SC surface with the composition (99.6:0:0.4, active material, carbon black, PTFE binder) to clarify the comparison between two main cathodes’ design.Finally, we found that the dry-processed SC electrode demonstrated superior performance in full-cell tests and show excellent cycle performance at high temperature (45 °C) and high voltage (2.8 to 4.5V). The enhanced performance observed in dry-processed electrodes using CNT was found to be primarily due to the reduced ion resistance in environments devoid of internal carbon black, as confirmed through comparison with wet-processed electrodes. Although electron conductivity was ensured through the conductive material, a significant decrease in performance was noted if the environment was not conducive to the movement of internal lithium-ion. And it is attributable to enhanced surface stability under high-voltage storage conditions with a reduced specific surface area compared to PC cathode and PC wet process condition. Figure 1

Superior thermal response of additive manufactured porous stainless steel with carbon nanotubes

The temperature rise in the battery cells during continuous operation leads to a thermal runaway that affects the life and performance of electric vehicles. For such reasons, heat sinks with high thermal conductivity will be of utmost importance in maintaining optimal operating temperatures. This paper presents the development of a 3D-printed SS 316L porous structure with carbon nanotubes coated on it through a chemical vapour deposition method to enhance thermal management. The carbon nanotubes (CNTs)-coated porous Stainless Steel (SS) structure showed enhanced thermal performance. It absorbed heat 7 % faster than the non-coated and dissipated heat 138 % more at a heat input of 36.5 W. For the fixed 120-second time, a temperature difference existed of 3.9 °C during heating and up to 4.4 °C during cooling. These results demonstrate that the CNT coating dramatically improves the thermal response of the porous SS structure. This original approach for integrating CNT coatings with 3D-printed porous SS structures opens up a potential avenue for the efficient design and manufacturing of a heat sink, thus increasing the reliability and durability of the battery systems in electric vehicles.

Advances in Carbon Nanotubes and Carbon Coatings as Conductive Networks in Silicon‐based Anodes

AbstractSilicon‐based anode has high theoretical capacity but suffers from poor electrical conductivity, large volume expansion, and unstable solid electrolyte interphase (SEI). Adding carbon nanotubes (CNTs) and carbon coatings are both very effective methods for addressing the above issues. The intrinsic sp2 covalent structure endows CNTs with excellent electrical conductivity, mechanical strength, and chemical stability, which makes them suitable for various energy storage applications, such as in lithium‐ion batteries (LIBs). Apart from the conductive network, CNTs can serve as current collectors, mechanical probes, and mechanical frameworks, and they have potential in the construction of next‐generation battery architectures. Carbon coatings are mixed ionic‐electronic conductors with good chemical stability that provide mechanical support and mitigate the volume expansion of Si‐based materials. This review outlines the advances in CNTs and carbon coatings as conductive networks in Si‐based anodes, as well as insights into their future development. It provides an in‐depth analysis of the percolation and mechanical mechanism of conductive networks, highlights the importance of flexible long‐range conductivity, and decouples the relationships between stress, interface stability, and electron/ion transfer.

Multifunctional Lithium Phytate/Carbon Nanotube Double-Layer-Modified Separators for High-Performance Lithium-Sulfur Batteries.

Li dendrite and the shuttle effect are the two primary hindrances to the commercial application of lithium-sulfur batteries (LSBs). Here, a multifunctional separator has been fabricated via successively coating carbon nanotubes (CNTs) and lithium phytate (LP) onto a commercial polypropylene (PP) separator to improve the performance of LSBs. The LP coating layer with abundant electronegative phosphate group as permselective ion sieve not only reduces the polysulfide shuttle but also facilitates uniform Li+ flux through the PP separator. And the highly conductive CNTs on the second layer act as a second collector to accelerate the reversible conversion of sulfide species. The synergistic effect of LP and CNTs further increases the electrolyte wettability and reaction kinetics of cells with a modified separator and suppresses the shuttle effect and growth of Li dendrite. Consequently, the LSBs present much enhanced rate performance and cyclic performance. It is expected that this study may generate an executable tactic for interface engineering of separator to accelerate the industrial application process of LSBs.

EVALUATING ACETONE AND METHANOL FOR ELECTROPHORETIC DEPOSITION OF SS 316L COATED WITH HYDROXYAPATITE/MULTIWALLED CARBON NANOTUBES DENTAL IMPLANTS: A FOCUS ON CORROSION RESISTANCE

Dental implants offer a reliable solution for replacing damaged tooth roots. This research investigates the comparative performance of acetone and methanol as suspension media in the fabrication of stainless steel type 316L-based dental implants using the Electrophoretic Deposition (EPD) method, a technique known for its simplicity and cost-effectiveness. Voltage variations of 20V, 30V, and 40V were applied to both acetone and methanol suspensions for a duration of 20 minutes. The morphology of the Hydroxyapatite/Multiwalled Carbon Nanotube (HA/MWCNT) coatings was meticulously characterized using Scanning Electron Microscopy (SEM). Corrosion resistance was evaluated through Potentiodynamic Polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS) techniques. Remarkably, at 30V, a homogeneous and crack-free coating was achieved, demonstrating superior corrosion resistance. This was further corroborated by the resistance values of 23.891 Ω and 114.990 Ω for the acetone and methanol samples, respectively. Additionally, the corrosion rates of 0.075 (mmpy) and 0.0004 (mmpy) for the acetone and methanol samples further emphasized the superiority of methanol as a suspension medium. These findings unequivocally establish methanol as the optimal choice for achieving superior deposition quality and corrosion resistance in the context of the EPD method for stainless steel type 316L-based dental implants.

Enhanced activity and durability of Pt nanoclusters catalyst by using nitrogen-doped carbon layer coated carbon nanotubes as anchors and nanowires for ORR

Platinum-based catalysts remain the top choice for oxygen reduction reaction (ORR) in fuel cells. However, their activity and durability in the acidic medium are still under improvement. In this work, the Pt nanoclusters anchored the nitrogen-doped carbon nanotubes (Pt-NCNTs) have been synthesized by using a series process of pyrrole coating on the CNTs and subsequent pyrolysis to the chemical immersion reduction of Pt ions. The inner CNTs of Pt-NCNTs function as the nanowires offering a high-speed pathway for electron transport, and the Pt nanoclusters increases the active sites. The theoretical calculation demonstrates that the local structural defects and the uneven charge distribution induced by nitrogen-containing functional groups and porous structure are favorable to capture Pt ions for the nucleation of Pt nanoclusters. Compared with the commercial 40 wt% Pt/C (0.94 and 0.80 V), the Pt-NCNTs-1000 with Pt loading amount of 33.0 wt% owns the more positive onset potential and half-wave potential of 0.97 and 0.81 V in the sulfuric acid medium. Meanwhile, the strong attachment of Pt nanoclusters on the nitrogen-doped porous carbon layer results in a stable interface to effectively prevent the metallic species from migration and agglomeration during the electrode reactions. Therefore, the ORR current of Pt-NCNTs-1000 retained 84.3% of the initial value after 50000 s operation superior to the commercial Pt/C (64.6%).

Magnetically Reusable Carbon Nanotube Coated Co‐based Catalysts towards Highly Efficient Transfer Hydrogenation of Nitroarenes

AbstractDevelopment of efficient and stable non‐noble metal catalysts applied to the catalytic transfer hydrogenation of nitroarenes under mild conditions is still challenging. Herein, we report magnetically recyclable catalysts prepared via simple two‐stage pyrolysis of Co‐MOF‐74 and melamine composites. The optimized catalyst Co@C/CNTs‐10‐700 shows excellent conversion and selectivity towards transfer hydrogenation of nitroarenes with different hydrogen donors. Its excellent stability against formic acid corrosion makes it can be used in a wide range. The excellent catalytic performance can be ascribed to the synergistic effect between carbon nanotubes and Co nanoparticles. Furthermore, the catalyst was easily recycled owing to its magnetism and reused up to ten consecutive cycles without significant loss of activity, indicating that the excellent catalytic stability holds great promise in fields of industrial application.

Carbon nanotube incorporated quaternized lignin-based loose nanofiltration membrane toward dye/salt separation

Lignin is a promising raw material for membrane fabrication due to its abundant oxygen-containing functional groups, branched molecular structure, and high abundance in the botanic field. In this report, polydopamine (PDA) coated carbon nanotubes (PCNTs) are synthesized. Then, a PCNT-incorporated lignin-based loose nanofiltration membrane is fabricated using quaternized lignin (QL) as a raw material, triphosgene (TP) as a crosslinker, and PCNTs as nanoadditive by interfacial polymerization. The results show that the PCNTs uniformly distribute in the QL-based separation layer providing quick diffusion paths for water molecules and salt ions. The coated PDA layer improves the chemical compatibility between the PCNTs and the separation layer. The incorporated PCNTs optimize the membrane microstructure and elevate the pure water permeance to 45.5 LMH bar−1. The membrane exhibits high rejections to various dyes (> 90%) and high salt permeation (> 90%), demonstrating an excellent dye/salt separation performance. Moreover, it has satisfactory capabilities for resisting dye adsorption and fouling, and its separation capability also has good tolerances to the acid, alkali, and active chlorine treatments. The quaternary ammonium ions and hydrophilic surface endow the membrane with favorable bactericidal property (99.3%) and bacteria-adhesion resistance. Besides, TP is a better crosslinker than trimesoyl chloride for optimizing the membrane microstructure and crosslinking degree in terms of dye/salt separation.

Dynamic behaviors of nickel coated carbon nanotubes reinforced ultra-high performance cementitious composites under high strain rate impact loading

Understanding the dynamic mechanical behaviors of materials is a prerequisite for reliably analyzing and predicting the dynamic response of structures, which is of great significance for transportation infrastructure and military engineering subjected to extreme loads, particularly dynamic loads at high strain rates. Nickel coated multi-walled carbon nanotubes (Ni-MWCNTs) show promise as a reinforcement to modify the dynamic mechanical behaviors of ultra-high performance cementitious composites (UHPCC). Because Ni-MWCNTs combine the high tensile strength and large aspect ratio characteristics of fibers with the nano effect of nanomaterials, as well as have excellent dispersibility due to the nickel plating on the CNTs’ surface, they effectively improve the dynamic mechanical properties of UHPCC under impact loading at high strain rates of about 100 s−1/300 s−1/500 s−1 and reduce the brittle damage degree of composites. The maximal increase in dynamic compressive strength and energy absorption capacity of UHPCC reaches 47.9% and 68.2%, respectively. This enhancement effect arises from that Ni-MWCNTs improve the microstructure and form multiple fine cracks, resulting in an increased energy consumption required for crack formation, propagation and coalescence. Additionally, the dynamic mechanical properties of Ni-MWCNTs reinforced UHPCC exhibit noticeable strain rate effects. Consequently, a strain rate-dependent logarithmic functional dynamic increase factor model and dynamic constitutive model of UHPCC filled with Ni-MWCNTs are modified herein for predicting and modeling the dynamic mechanical behaviors of composites.

A Solar Evaporator Based on Polypyrrole Coated 3D Carbon Nanotube Materials for Efficient Solar-Driven Vapor Generation.

Highly porous light absorbers are fabricated based on polypyrrole (PPy)-coated carbon nanotube (CNT). Carbon nanotube sponge (CNTS) or carbon nanotube array (CNTA) with three-dimensional (3D) network structure is the framework of porous light absorbers. Both PPy@CNTS and PPy@CNTA composites exhibit excellent light absorption of the full solar spectrum. The CNTS and CNTA with porous structures have extremely large effective surface area for light absorption and for water evaporation that has great practical benefit to the solar-driven vapor generation. The PPy layer on CNT sidewalls significantly improves the hydrophilicity of porous CNTS and CNTA. The good wettability of water on CNT sidewalls makes water transport in porous CNT materials highly efficient. The PPy@CNTS and PPy@CNTA light absorbers achieve high water evaporation rates of 3.35 and 3.41kg m-2 h-1 , respectively, under 1-sun radiation. The orientation of nano channels in CNTA-based light absorbers also plays an important role in the solar-driven vapor generation. The water transport and vapor escape are more efficient in CNTA-based light absorbers as compared to the CNTS-based light absorbers due to the relatively short path for the water transport and the vapor escape in CNTA-based light absorbers.

Integrated Electrostimulation Cell Culture Systems Driven by Chemically Modified Twistron Mechanical Energy Harvesting Electrodes

AbstractDeveloping mechanical energy harvesters for electrical stimulation (ES) needed to augment cell behavior is a burgeoning area of interest. Mechanical energy harvesters that can generate electrical energy in electrolyte‐containing aqueous environments offer a unique solution for delivering ES to cells. In this work, a fully integrated ES assembly (FESA) is introduced that comprises coiled polydopamine (PDA) containing carbon nanotube yarn (CNT) harvesters, serving as ES generators, and poly(3,4‐ethylenedioxythiophene) coated carbon nanotube (PEDOT/CNT) sheets employed as a conductive scaffold. The PDA containing CNT (PDA/CNT) yarn, a novel twistron electrode, achieves an enhanced electrical power at a lower matching impedance than coiled CNT yarn to efficiently transfer ES to the conductive scaffold. The PEDOT used for the scaffold provides a suitable surface for cell adhesion and low resistance for effective ES transmission. In addition, the upscaled array of coiled PDA/CNT yarns provides an ES current density range up to 75.4 µA cm−2, which is much higher than for ES systems using different mechanical energy harvesters. This FESA is designed to provide an optimal level of ES for the proliferation and differentiation of chondrocytes. The findings illuminate the potential of chemically modified twistron energy harvesters as an innovative and effective strategy to promote biological response.

Order-of-Magnitude Increase in Carbon Nanotube Yield Based on Modeling Transient Diffusion and Outgassing of Water From Reactor Walls

Abstract While reactor wall preconditioning was previously shown to influence the yield in chemical vapor deposition (CVD), especially for the growth of carbon nanotubes (CNTs), it was limited to studying accumulating carbonaceous deposits over a number of runs. However, the effects of temperature and duration as the reactor walls are exposed to hot humidity for extended periods between growth runs were not previously studied systematically. Here, we combine experimental measurements with a mathematical model to elucidate how the thermochemical history of reactor walls impacts growth yield, especially knowing that only a specific range of humidity promotes growth. Importantly, we demonstrate a one-order-of-magnitude higher CNT yield by increasing the interim, i.e., the time between runs. We explain the results based on previously unexplored process sensitivity to trace amounts of oxygen-containing species in the reactor. In particular, we model the effect of small amounts of water vapor being desorbed from reactor walls during growth. Our results reveal the outgassing dynamics and show the underlying mechanism of generating growth-promoting molecules. By installing a humidity sensor in our custom-designed multizone rapid thermal CVD reactor, we are able to uniquely correlate the amount of moisture within the reactor to real-time measurements of growth kinetics, as well as ex situ characterization of CNT alignment and atomic defects. Our findings enable a scientifically grounded approach toward both boosting growth yield and improving its consistency by reducing run-to-run variations. Accordingly, engineered dynamics recipes with added preprocessing steps can be envisioned to leverage this phenomenon for improving manufacturing process scalability and robustness.

Nucleate boiling enhancement on hybrid graphene-nanoplatelets/carbon nanotubes coatings for light-emitting diode cooling

This study explores the remarkable enhancement of light-emitting diode (LED) cooling through nucleate boiling using hybrid coatings of graphene-nanoplatelets (GNP) and carbon nanotubes (CNT). The introduction of oxygenated functional groups in the cured GNP and CNT coatings fosters improved hydrophilicity, promoting water intercalation within the nanostructures. The hybrid cured GNP/CNT coating demonstrates superior nucleate boiling performance compared to individual cured GNP and CNT coatings, owing to complementary mechanisms. Cured CNT facilitate efficient water permeation by enabling water molecules to infiltrate through their inner cores and intertwining tube spaces, while cured GNP offer an escape route for trapped water molecules and absorbed latent heat due to their layer-by-layer arrangement of graphene sheets with broadened interlayers. As compared to the bare copper surface, the LED cooled using the hybrid cured GNP/CNT coating exhibits a maximum temperature drop of 20.7 °C and an enhancement up to 1212 % in heat transfer coefficient, surpassing the cured GNP and CNT coatings. Moreover, the hybrid cured GNP/CNT coating improves the LED illuminance by 16.6 %, validating its potency in improving cooling performance. These findings highlight the potential of GNP/CNT hybrid coatings in advancing nucleate boiling cooling technologies and offer valuable insights into optimizing LED performance for high-quality lighting solutions.

Pristine and Coated Carbon Nanotube Sheets—Characterization and Potential Applications

A carbon nanotube (CNT) sheet is a nonwoven fabric that is being evaluated for use in different textile applications. Several properties of pristine CNT sheets and CNT sheets coated with a polysilazane sealant and coating were measured and compared in the paper. The polysilazane coating is used to reduce the shedding of CNT fibers from the sheet when the sheet is in contact with surfaces. Most fabrics show some shedding of fibers during the washing or abrasion of the fabric. This study showed that the coating reduces the shedding of fibers from CNT fabric. The coating also increased the flame resistance of the fabric. The pristine and coated sheets both have low strength but high strain to failure. The pristine and coated CNT sheet densities are 0.48 g/cc and 0.65 g/cc, respectively. The pristine CNT sheet is approximately 27 μ thick. The coated sheet is approximately 24 μ thick. The coating may have densified the sheet, making it thinner. The thickness of the compliant sheets was difficult to measure and is a source of error in the properties. Characterization results are given in this paper. The results are for comparison purposes and not to establish material properties data. Possible applications for CNT sheets are briefly discussed.