- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- Carbon nanotubes
- Magnetic focused
- Field emission cathodes
- Travelling wave tubes
- Heat Trap
- outgassing
- lifetime
- current stability
- cathode
- thermionic emission
- Electronic Science and Technology
- Nanomaterials and Technology
- University of British Columbia
- Beijing Vacuum Electronics Research Institute
- Sun Yat-sen University
-
Highly Hydrophobic Conducting Nanocomposites Based on a Fluoropolymer with Carbon Nanotubes
摘要： A procedure was suggested for preparing highly hydrophobic conducting coatings based on fluoropolymers with carbon nanotubes of two types: Taunit-MD and carbon nanotubes functionalized with alkyl groups. The surface resistance, contact angle, sliding angle, and surface roughness were measured; structural features of the nanocomposites were studied. The properties of the coatings obtained depend on the concentration and type of the carbon nanotubes used. Introduction of functionalized carbon nanotubes into a fluoropolymer matrix allows preparation of coatings with higher values of the sliding angle and electrical resistance. The contact angle and sliding angle depend on the surface roughness and structure in different fashions.
关键词： carbon nanotubes,electrical conductivity,surface roughness,hydrophobicity,nanocomposites
更新于2025-09-23 15:22:29
-
High-Temperature Filter Based on Silicon Carbide for Aggressive Fluids and Gases
摘要： In this paper, we developed a production method for items based on mesh silicon carbide that are suitable for cleaning aggressive fluids, melts, and gases from foreign inclusions at high operating temperatures. The resulting products can also be used for filtering fuel mixtures.
关键词： carbon fibers,silicization,silicon carbide,microstructure,composite filter
更新于2025-09-23 15:22:29
-
Green Hydrothermal Synthesis of Fluorescent Carbon Dots from Glucose and Taurine for Fe3+ and pH Sensing
摘要： Carbon nanodots (C-dots), as a class of heavy-metal-free fluorescent nonmaterial have drawn increasing attention due to their strong photoluminescence (PL), good biocompatibility, and low toxicity. Herein, we synthesize nontoxic fluorescent C-dots by hydrothermal treatment of the mixture of glucose and taurine, in which process the formation and the surface passivation of C-dots take place simultaneously. The influence of reaction temperature, reaction time and feed ratio of glucose to taurine on the PL property of C-dots is studied. As the C-dots exhibit sensitive pH and iron ion dependent PL property, they can be used for pH and Fe3+ sensing in solutions.
关键词： Nanoparticles,Optical materials and properties,Carbon materials
更新于2025-09-23 15:22:29
-
The Sonogel-Carbon-PEDOT Material: An Innovative Bulk Material for Sensor Devices
摘要： The synthesis of a new bulk material based on silicon oxide and poly-(3,4-ethylenedioxythiophene) (PEDOT), the Sonogel-Carbon-PEDOT material, is carried out. The main purpose is to obtain a bare conducting material, aided by statistical experimental design, able to be used as transducer for electrochemical devices. This new material tries also to solve out the degradation and fouling drawbacks related to PEDOT-based layer devices by simply polishing its surface in a gently way. The resulting Sonogel-Carbon-PEDOT material shows excellent electrochemical properties, renewable surface and stability by using simple, low cost, and versatile synthesis method. As far as we are concerned, this is the first time that this kind of bulk material is reported. The resulting material was characterized by different techniques: SEM, EDS and Raman spectroscopy. Sonogel-Carbon-PEDOT was also electrochemically characterized for the assessment of the electrochemical performance of the resulting sensor device. Ascorbic acid was selected as reference analyte, obtaining good sensitivity and limit of detection: 319.8 μA mM-1cm-2 and 6.42 μM, respectively, in the concentration range 0.01–3.45 mM. Furthermore, repeatability and reproducibility studies (RSD<3%), were also very satisfactory. Finally, the Sonogel-Carbon-PEDOT sensor was successfully applied to the determination of ascorbic acid in a pharmaceutical formulation and biological samples, obtaining good recovery percentage (95–105%).
关键词： electrochemical properties,sensor devices,Sonogel-Carbon-PEDOT,conducting polymers,ascorbic acid
更新于2025-09-23 15:22:29
-
Removal of Ethylene and By-Products using Packed Bed Dielectric Barrier Discharge with Ag Nanoparticle-Loaded Zeolite
摘要： Ethylene gas was decomposed using packed-bed type dielectric barrier discharge (PBDBD) plasma reactor to keep freshness of fruits. The ethylene gas was diluted with gas mixture of nitrogen, oxygen and carbon dioxide as simulated gas in the transportation container. The PBDBD plasma was generated by a pulse switching power supply which consisted of MOS-FET switching devices, capacitors and pulse transformers. The Ag nanoparticle-loaded zeolite as catalyst has high activity and good performance for reduction of ozone and oxidizing carbon monoxide at room temperature. The Ag nanoparticle-loaded zeolite pellets enhanced ethylene removal efficiency and reduced ozone and carbon monoxide produced by the plasma treatment. It was confirmed that the carbon monoxide in the gas simulated dry air composition was oxidized using Ag nanoparticle-loaded zeolite with plasma treatment.
关键词： plasma,catalyst,ethylene,PBDBD,carbon monoxide
更新于2025-09-23 15:22:29
-
History and National Initiatives of Carbon Nanotube and Graphene Research in Brazil
摘要： In this article, we first introduce and discuss the fundamental science of carbon nanomaterials (especially nanotubes and graphene) and the different technological applications from using these materials. We then discuss the first works of Brazilians scientists, done in collaboration with scientists of other countries and, in particular, the role of Prof. M. S. Dresselhaus from MIT, US, in the development of the nanocarbon science in Brazil. We briefly discuss some experimental and theoretical works about nanotubes and graphene done in Brazil in the late 1990s and early 2000s, and the formation of the first Brazilian network on carbon nanotubes in 2005. We present the activities of the National Institute of Science and Technology (INCT) in Carbon Nanomaterials (CN) created in 2009. A scientometric analysis is used to describe the INCT-CN network formation. Finally, we present the Center of Technology in Nanomaterials (CTNano) installed at UFMG, where pilot plants were developed to produce graphene and nanotubes at large scales, and the work being done at the center in collaboration with companies aiming to solve specific technological problems and to create bridges between the academic and the industrial sectors.
关键词： Graphene,Scientometric Analysis,Nanotechnology,Carbon nanotubes
更新于2025-09-23 15:22:29
-
Preparation of Mesoporous Fe2O3-Supported ZSM-5 Zeolites by Carbon-Templating and their Evaluation as Photo-Fenton Catalysts to Degrade Organic Pollutant
摘要： Mesoporous Fe2O3-supported ZSM-5 zeolites were prepared by carbon-templating and subsequently evaluated as photo-Fenton catalysts to degrade a dye used as a model heavy organic pollutant. The synthesis procedure of the mesoporous ZSM-5 zeolites was performed employing a nucleating gel and carbon particles as mesopores template. Thereafter, the precursor salt of the iron oxide (Fe2O3) was impregnated and then calcined to obtain the final catalyst. For comparison purposes, a conventional Fe2O3-supported ZSM-5 zeolite was also prepared. The results showed that the amount of intracrystalline mesopores formed in the ZSM-5 crystals was influenced by the amount of carbon added into the synthesis mixture. In comparison to the conventional prepared catalyst, the mesoporous Fe2O3/ZSM-5 ones showed an improved performance in the degradation of the target organic pollutant by the photo-Fenton reaction, which was attributed to the improvement of their textural properties as consequence of the mesopores generation.
关键词： Fe2O3-supported ZSM-5,Mesoporous ZSM-5,carbon template,dye degradation,photo-Fenton reaction
更新于2025-09-23 15:22:29
-
Dynamic operation of liquid crystal cell with inherently nanogroove-featured aligned carbon nanotube sheets
摘要： The use of a highly aligned carbon nanotube (CNT) sheet as a multifunctional constituent for liquid crystal (LC) displays and electro-optic LC applications is assessed. The CNT sheet can perform a dual function: one is an alignment layer for LCs, replacing the commonly used rubbed polyimide film, and the other is a transparent conductive layer, taking the place of indium tin oxide. The hydrophobic treatment improved the adhesion quality between aligned CNT bundles and the glass substrate, which helps to preserve the inherently aligned nanogroove morphology of transparent CNT sheets. The test LC display cells, comprising 4-cyano-4′-pentylbiphenyl molecules sandwiched between CNT-sheet-on-glass substrates, demonstrate the operation characteristics comparable to that of the conventional cell under temperature variation and ac electric field of 1 kHz. The results offer a possibility of deploying multifunctional CNT-sheet alignment layers in LC-based devices, especially in the future flexible display applications.
关键词： Indium-tin oxide transparent conductor,Aligned carbon nanotube sheets,Liquid crystal cells,Polyimide alignment layer for liquid crystal display
更新于2025-09-23 15:22:29
-
Performance comparison between a miniaturized and a conventional near infrared reflectance (NIR) spectrometer for characterizing soil carbon and nitrogen
摘要： Miniaturized near infrared spectrometers are now available, at more affordable prices than conventional spectrometers, but their performances have been poorly studied to date. This paper aimed at comparing the performances of the JDSU MicroNIR 2200 spectrophotometer (weight < 0.1 kg) with those of a conventional bench-top instrument for predicting carbon and nitrogen contents in laboratory conditions, on a range of representative Malagasy soils. Though its noticeably narrower and less resolved spectra (1151–2186 nm at 8.15 nm step vs. 1100–2498 nm at 2 nm step), the microspectrometer yielded predictions in independent validation that were almost as accurate as those of the conventional instrument (standard errors of prediction were 4.6 vs. 3.4 gC kg?1 after bias correction, and 0.36 vs. 0.35 gN kg?1, respectively). Due to noisy features, the MicroNIR spectra needed mathematical pretreatment (e.g. standard normal variate SNV), and bias correction for C, for providing accurate predictions, while the raw absorbance spectra from the conventional instrument did not. Furthermore, building multivariate models with MicroNIR spectra required less latent variables than with their conventional counterparts, and these models were less prone to performance degradation when applied to independent validation samples. Fitting the spectra of the conventional instrument to those of the MicroNIR (1150–2182 nm at 2 or 8 nm step) showed that (moderately) less accurate MicroNIR predictions could be firstly attributed to narrower spectral range rather than to poorer resolution. Considering their performances, such microspectrometers could thus represent a cost-effective alternative to conventional spectrometers. They have now to be tested in field conditions.
关键词： Near infrared reflectance spectroscopy (NIRS),Soil organic carbon,Madagascar,Soil total nitrogen,Microspectrometer
更新于2025-09-23 15:22:29
-
A Simple Route in Fabricating Carbon-Modified Titania Films with Glucose and Their Visible-Light-Responsive Photocatalytic Activity
摘要： Carbon-modi?ed titania (C–TiO2) ?lms were easily prepared by using an impregnation process with a glucose-containing TiO2 sol. Through controlling calcination conditions, the as-obtained C–TiO2 products exhibited highly photocatalytic activity for the degradation of gaseous NOx under visible light and ultraviolet illumination. The effects of carbon content and calcination temperature on the photocatalytic performances and their photochemical and physical properties were investigated. Carbonaceous species on the TiO2 surface enhanced the visible-light absorption of TiO2 ?lms; however, an excessive amount of carbon on the TiO2 surface reduced its photocatalytic ability due to the serious coverage effect on active sites. The results show that a suitable glucose addition is about 50–100% of the weight of TiO2 content and the optimized calcination temperature is 300 ?C, which leads to better photocatalytic activity under ultraviolet and visible- light irradiations. Accordingly, the simple-prepared C–TiO2 ?lms functioned as visible-light-responsive catalysts, allowing for a feasible producing route for real applications.
关键词： glucose,titania ?lm,impregnation,carbon-modi?ed,visible-light-responsive
更新于2025-09-23 15:22:29