期刊文献+
共找到13,008篇文章
< 1 2 250 >
每页显示 20 50 100
Enhancing the Interaction of Carbon Nanotubes by Metal-Organic Decomposition with Improved Mechanical Strength and Ultra-Broadband EMI Shielding Performance 被引量:3
1
作者 Yu-Ying Shi Si-Yuan Liao +7 位作者 Qiao-Feng Wang Xin-Yun Xu Xiao-Yun Wang Xin-Yin Gu You-Gen Hu Peng-Li Zhu Rong Sun Yan-Jun Wan 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第7期281-294,共14页
The remarkable properties of carbon nanotubes(CNTs)have led to promising applications in the field of electromagnetic inter-ference(EMI)shielding.However,for macroscopic CNT assemblies,such as CNT film,achieving high ... The remarkable properties of carbon nanotubes(CNTs)have led to promising applications in the field of electromagnetic inter-ference(EMI)shielding.However,for macroscopic CNT assemblies,such as CNT film,achieving high electrical and mechanical properties remains challenging,which heavily depends on the tube-tube interac-tions of CNTs.Herein,we develop a novel strategy based on metal-organic decomposition(MOD)to fabricate a flexible silver-carbon nanotube(Ag-CNT)film.The Ag particles are introduced in situ into the CNT film through annealing of MOD,leading to enhanced tube-tube interactions.As a result,the electrical conductivity of Ag-CNT film is up to 6.82×10^(5) S m^(-1),and the EMI shielding effectiveness of Ag-CNT film with a thickness of~7.8μm exceeds 66 dB in the ultra-broad frequency range(3-40 GHz).The tensile strength and Young’s modulus of Ag-CNT film increase from 30.09±3.14 to 76.06±6.20 MPa(~253%)and from 1.12±0.33 to 8.90±0.97 GPa(~795%),respectively.Moreover,the Ag-CNT film exhibits excellent near-field shield-ing performance,which can effectively block wireless transmission.This innovative approach provides an effective route to further apply macroscopic CNT assemblies to future portable and wearable electronic devices. 展开更多
关键词 EMI shielding Mechanical strength carbon nanotubes Metal-organic decomposition Flexibility
下载PDF
Low‑Cost,Scalable Fabrication of All‑Fabric Piezoresistive Sensors via Binder‑Free,In‑Situ Welding of Carbon Nanotubes on Bicomponent Nonwovens 被引量:2
2
作者 Guangliang Tian Yihan Shi +7 位作者 Jixia Deng Wenhua Yu Leihang Yang Yi Lu Yi Zhao Xiangyu Jin Qinfei Ke Chen Huang 《Advanced Fiber Materials》 SCIE EI CAS 2024年第1期120-132,共13页
Wearable piezoresistive sensors have shown enormous application prospects in flexible electronics and human-machine interfaces.However,current piezoresistive sensors suffer from common deficiencies including high fabr... Wearable piezoresistive sensors have shown enormous application prospects in flexible electronics and human-machine interfaces.However,current piezoresistive sensors suffer from common deficiencies including high fabrication cost,poor comfort and low attachment fastness of conductive substances on substrates,thereby impeding their large-scale production and practical use.Herein,a three-dimensional all-fabric piezoresistive sensor is reported based on coating multi-wall carbon nanotubes(MWCNTs)on bicomponent nonwovens composed of core-sheath fibers.The combination of core-sheath fibers with a heat-induced welding strategy greatly improves the adhesion fastness and stability of MWCNT network.The multi-layered all-fabric structure provides as-prepared sensors with high sensitivity(9.43%kPa^(-1)in 0-10 kPa and 0.076%kPa^(-1)in 20-120 kPa),wide pressure-sensing range(0-120 kPa),fast response/relaxation time(100 and 60 ms),good reproducibility and air permeability.Application of the sensor is demonstrated through the detection of human activities(such as pulse,cough and joint movements)and the wireless monitoring of forefinger bending.Moreover,our sensor is fabricated out of cost-effective materials,using scalable approach without using glue or binders.The method established in this work may provide an efficient strategy for the design and production of high-performance all-fabric piezoresistive sensors. 展开更多
关键词 Piezoresistive pressure sensors Core-sheath fibers All-fabric Multi-wall carbon nanotubes In-situ welding
原文传递
In situ formation of multiple catalysts for enhancing the hydrogen storage of MgH_(2) by adding porous Ni_(3)ZnC_(0.7)/Ni loaded carbon nanotubes microspheres 被引量:2
3
作者 Bing Zhang Xiubo Xie +6 位作者 Yukun Wang Chuanxin Hou Xueqin Sun Yuping Zhang Xiaoyang Yang Ronghai Yu Wei Du 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1227-1238,共12页
MgH_(2) is considered one of the most promising hydrogen storage materials because of its safety,high efficiency,high hydrogen storage quantity and low cost characteristics.But some shortcomings are still existed:high... MgH_(2) is considered one of the most promising hydrogen storage materials because of its safety,high efficiency,high hydrogen storage quantity and low cost characteristics.But some shortcomings are still existed:high operating temperature and poor hydrogen absorption dynamics,which limit its application.Porous Ni_(3)ZnC_(0.7)/Ni loaded carbon nanotubes microspheres(NZC/Ni@CNT)is prepared by facile filtration and calcination method.Then the different amount of NZC/Ni@CNT(2.5,5.0 and 7.5 wt%)is added to the MgH_(2) by ball milling.Among the three samples with different amount of NZC/Ni@CNT(2.5,5.0 and 7.5 wt%),the MgH_(2)-5 wt%NZC/Ni@CNT composite exhibits the best hydrogen storage performances.After testing,the MgH_(2)-5 wt%NZC/Ni@CNT begins to release hydrogen at around 110℃ and hydrogen absorption capacity reaches 2.34 wt%H_(2) at 80℃ within 60 min.Moreover,the composite can release about 5.36 wt%H_(2) at 300℃.In addition,hydrogen absorption and desorption activation energies of the MgH_(2)-5 wt%NZC/Ni@CNT composite are reduced to 37.28 and 84.22 KJ/mol H_(2),respectively.The in situ generated Mg_(2)NiH_(4)/Mg_(2)Ni can serve as a"hydrogen pump"that plays the main role in providing more activation sites and hydrogen diffusion channels which promotes H_(2) dissociation during hydrogen absorption process.In addition,the evenly dispersed Zn and MgZn2 in Mg and MgH_(2) could provide sites for Mg/MgH_(2) nucleation and hydrogen diffusion channel.This attempt clearly proved that the bimetallic carbide Ni_(3)ZnC_(0.7) is a effective additive for the hydrogen storage performances modification of MgH_(2),and the facile synthesis of the Ni_(3)ZnC_(0.7)/Ni@CNT can provide directions of better designing high performance carbide catalysts for improving MgH_(2). 展开更多
关键词 Mg-based hydrogen storage material Ni_(3)ZnC_(0.7)/Ni@CNT particles Ni loaded carbon nanotubes Multiple catalysts.
下载PDF
Heat transfer enhanced inorganic phase change material compositing carbon nanotubes for battery thermal management and thermal runaway propagation mitigation 被引量:1
4
作者 Xinyi Dai Ping Ping +4 位作者 Depeng Kong Xinzeng Gao Yue Zhang Gongquan Wang Rongqi Peng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期226-238,I0006,共14页
Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase chan... Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase change material(PCM)with nonflammability has the potential to achieve this dual function.This study proposed an encapsulated inorganic phase change material(EPCM)with a heat transfer enhancement for battery systems,where Na_(2)HPO_(4)·12H_(2)O was used as the core PCM encapsulated by silica and the additive of carbon nanotube(CNT)was applied to enhance the thermal conductivity.The microstructure and thermal properties of the EPCM/CNT were analyzed by a series of characterization tests.Two different incorporating methods of CNT were compared and the proper CNT adding amount was also studied.After preparation,the battery thermal management performance and TR propagation mitigation effects of EPCM/CNT were further investigated on the battery modules.The experimental results of thermal management tests showed that EPCM/CNT not only slowed down the temperature rising of the module but also improved the temperature uniformity during normal operation.The peak battery temperature decreased from 76℃to 61.2℃at 2 C discharge rate and the temperature difference was controlled below 3℃.Moreover,the results of TR propagation tests demonstrated that nonflammable EPCM/CNT with good heat absorption could work as a TR barrier,which exhibited effective mitigation on TR and TR propagation.The trigger time of three cells was successfully delayed by 129,474 and 551 s,respectively and the propagation intervals were greatly extended as well. 展开更多
关键词 Inorganic phase change material carbon nanotube Battery thermal management Thermal runaway propagation Fire resistance ENCAPSULATION
下载PDF
A review of carbon nanotubes in modern electrochemical energy storage
5
作者 SONG Yao-ming QIU Shi-xin +7 位作者 FENG Shu-xin ZUO Rui ZHANG Ya-ting JIA Ke XIA Xue CHEN Ming-ming JI Ke-meng WANG Cheng-yang 《新型炭材料(中英文)》 SCIE EI CAS CSCD 北大核心 2024年第6期1037-1074,共38页
The quest for sustainable energy storage solutions is more critical than ever,with the rise in global energy demand and the urgency of transition from fossil fuels to renewable sources.Carbon nanotubes(CNTs),with thei... The quest for sustainable energy storage solutions is more critical than ever,with the rise in global energy demand and the urgency of transition from fossil fuels to renewable sources.Carbon nanotubes(CNTs),with their exceptional electrical conduct-ivity and structural integrity,are at the forefront of this endeavor,offering promising ways for the advance of electrochemical energy storage(EES)devices.This review provides an analysis of the synthesis,properties,and applications of CNTs in the context of EES.We explore the evolution of CNT synthesis methods,including arc discharge,laser ablation,and chemical vapor deposition,and highlight the recent developments in metal-organic framework-derived CNTs and a novel CNT aggregate with a three-dimensional ordered macroporous structure.We also examine the role of CNTs in improving the performance of various EES devices such as lith-ium-ion,lithium-metal,lithium-sulfur,sodium,and flexible batteries as well as supercapacitors.We underscore the challenges that remain,including the scalability of CNT synthesis and the integration of CNTs in electrode materials,and propose potential solu-tions and future research directions.The review presents a forward-looking perspective on the pivotal role of CNTs in shaping the fu-ture of sustainable EES technologies. 展开更多
关键词 carbon nanotubes CNT synthesis Metal-ion batteries Lithium-sulfur batteries Flexible batteries SUPERCAPACITORS
下载PDF
Covalent organic frameworks/carbon nanotubes composite with cobalt(II)pyrimidine sites for bifunctional oxygen electrocatalysis
6
作者 Zhuangzhuang Wu Lijuan Feng +6 位作者 Zhe Lu Xinxin Yu Yuzhen Zhao Junming Luo Shaolei Wang Xinlong Tian Qi Chen 《Nano Materials Science》 EI CAS CSCD 2024年第4期419-427,共9页
With characteristics and advantages of functional composite materials,they are commendably adopted in numerous fields especially in oxygen electrocatalysis,which is due to the significant synergies between various com... With characteristics and advantages of functional composite materials,they are commendably adopted in numerous fields especially in oxygen electrocatalysis,which is due to the significant synergies between various components.Herein,a novel bifunctional oxygen electrocatalyst(Co-CNT@COF-Pyr)has been synthesized through in-situ growth of covalent organic frameworks(COFs)layers on the outer surface of highly conductive carbon nanotubes(CNTs)followed by coordination with Co(Ⅱ).For electrocatalytic OER,Co-CNT@COF-Pyr reveals a low overpotential(438 mV)in alkaline electrolyte(1.0 M aqueous solution of KOH)with a current density of 10 mA cm^(-2),which is comparable to most discovered COF-based catalysts.For electrocatalytic ORR,CoCNT@COF-Pyr exhibits a low H_(2)O_(2) yield range(9.0%-10.1%)and a reaction pathway close to 4e^(-)(n=3.82-3.80)in alkaline electrolyte(0.1 M aqueous solution of KOH)within the test potential range of 0.1-0.6 V vs.RHE,which is superior to most reported COF-based catalysts.Hence,this research could not only offer an innovative insight into the construction of composites,but also facilitate the practical application of renewable fuel cells,closed water cycle,and rechargeable metal-air batteries. 展开更多
关键词 Oxygen electrocatalysis Covalent organic frameworks carbon nanotubes Composite materials
下载PDF
Hollow tubes constructed by carbon nanotubes self-assembly for CO_(2) capture
7
作者 CHEN Xu-rui WU Jun +1 位作者 GU Li CAO Xue-bo 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2256-2267,共12页
Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their mac... Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their macroscopic assembly.The present study employed a gentle and direct self-assembly technique,wherein controlled growth of CNT sheaths occurred on the metal wire’s surface,followed by etching of the remaining metal to obtain the hollow tubes composed of CNTs.By controlling the growth time and temperature,it is possible to alter the thickness of the CNTs sheath.After immersing in a solution containing 1 g/L of CNTs at 60℃ for 24 h,the resulting CNTs layer achieved a thickness of up to 60μm.These hollow CNTs tubes with varying inner diameters were prepared through surface reinforcement using polymers and sacrificing metal wires,thereby exhibiting exceptional attributes such as robustness,flexibility,air tightness,and high adsorption capacity that effectively capture CO_(2) from the gas mixture. 展开更多
关键词 carbon nanotubes SELF-ASSEMBLY hollow tubes CO_(2) capture
下载PDF
Hollow ZIF-67-derived Co@N-doped carbon nanotubes boosting the hydrogenation of phenolic compounds to alcohols
8
作者 Zhihao Guo Jiuxuan Zhang +3 位作者 Lanlan Chen Chaoqun Fan Hong Jiang Rizhi Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期157-166,共10页
The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability,environmental friendliness,and non-toxicity is of great importance.Herein,a series of Co-based catalysts,named... The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability,environmental friendliness,and non-toxicity is of great importance.Herein,a series of Co-based catalysts,named Co@NCNTs,were designed and constructed by direct pyrolysis of hollow ZIF-67(HZIF-67)under H_(2)/Ar atmosphere.The evolution of the catalyst surface from the shell layer assembled by ZIF-67-derived particles to the in situ-grown hollow nitrogen-doped carbon nanotubes(NCNTs)with certain length and density is achieved by adjusting the pyrolysis atmosphere and temperature.Due to the synergistic effects of in situ-formed hollow NCNTs,well-dispersed Co nanoparticles,and intact carbon matrix,the as-prepared Co@NCNTs-0.10-450 catalyst exhibits superior catalytic performance in the hydrogenation of phenolic compounds to alcohols.The turnover frequency value of Co@NCNTs-0.10-450is 3.52 h^(-1),5.9 times higher than that of Co@NCNTs-0.40-450 and 4.5 times higher than that of Co@NCNTs-0.10-550,exceeding most previously reported non-noble metal catalysts.Our findings provide new insights into the development of non-precious metal,efficient,and cost-effective metal-organic framework-derived catalysts for the hydrogenation of phenolic compounds to alcohols. 展开更多
关键词 Phenolic compounds Hollow ZIF-67 pyrolysis Nitrogen-doped carbon nanotubes Reduction Multiphase reaction Catalysis
下载PDF
Superior Anodic Lithium Storage in Core–Shell Heterostructures Composed of Carbon Nanotubes and Schiff-Base Covalent Organic Frameworks
9
作者 Nan Jiang Mengpei Qi +3 位作者 Yalong Jiang Yin Fan Shiwei Jin Yingkui Yang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第6期150-157,共8页
Covalent organic frameworks(COFs)after undergoing the superlithiation process promise high-capacity anodes while suffering from sluggish reaction kinetics and low electrochemical utilization of redox-active sites.Here... Covalent organic frameworks(COFs)after undergoing the superlithiation process promise high-capacity anodes while suffering from sluggish reaction kinetics and low electrochemical utilization of redox-active sites.Herein,integrating carbon nanotubes(CNTs)with imine-linked covalent organic frameworks(COFs)was rationally executed by in-situ Schiff-base condensation between 1,1′-biphenyl]-3,3′,5,5′-tetracarbaldehyde and 1,4-diaminobenzene in the presence of CNTs to produce core–shell heterostructured composites(CNT@COF).Accordingly,the redox-active shell of COF nanoparticles around one-dimensional conductive CNTs synergistically creates robust three-dimensional hybrid architectures with high specific surface area,thus promoting electron transport and affording abundant active functional groups accessible for electrochemical utilization throughout the whole electrode.Remarkably,upon the full activation with a superlithiation process,the as-fabricated CNT@COF anode achieves a specific capacity of 2324 mAh g^(−1),which is the highest specific capacity among organic electrode materials reported so far.Meanwhile,the superior rate capability and excellent cycling stability are also obtained.The redox reaction mechanisms for the COF moiety were further revealed by Fourier-transform infrared spectroscopy in conjunction with X-ray photoelectron spectroscopy,involving the reversible redox reactions between lithium ions and C=N groups and gradual electrochemical activation of the unsaturated C=C bonds within COFs. 展开更多
关键词 heterostructured anode core-shell nanostructures carbon nanotubes polymeric Schiff-bases covalent organic frameworks
下载PDF
Self-templating synthesis of biomass-based porous carbon nanotubes for energy storage and catalytic degradation applications
10
作者 Manman Xu Shiqi Fu +7 位作者 Yukai Wen Wei Li Qiongfang Zhuo Haida Zhu Zhikeng Zheng Yuwen Chen Anqi Wang Kai Yan 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第3期584-595,共12页
Dwindling energy sources and a worsening environment are huge global problems,and biomass wastes are an under-exploited source of material for both energy and material generation.Herein,self-template decoction dregs o... Dwindling energy sources and a worsening environment are huge global problems,and biomass wastes are an under-exploited source of material for both energy and material generation.Herein,self-template decoction dregs of Ganoderma lucidum-derived porous carbon nanotubes(ST-DDLGCs)were synthesized via a facile and scalable strategy in response to these challenges.ST-DDLGCs exhibited a large surface area(1731.51 m^(2)g^(-1))and high pore volume(0.76 cm^(3)g^(-1)),due to the interlacing tubular structures of precursors and extra-hierarchical porous structures on tube walls.In the ST-DDLGC/PMS system,the degradation efficiency of capecitabine(CAP)reached~97.3%within 120 min.Moreover,ST-DDLGCs displayed high catalytic activity over a wide pH range of 3–9,and strong anti-interference to these typical and ubiquitous anions in wastewater and natural water bodies(i.e.,H_(2)PO_(4)^(-),NO_(3)^(-),Cl^(-) and HCO_(3)^(-)),in which a ^(1)O_(2)-dominated oxidation was identified and non-radical mechanisms were deduced.Additionally,ST-DDLGC-based coin-type symmetrical supercapacitors exhibited outstanding electrochemical performance,with specific capacitances of up to 328.1 F g^(-1)at 0.5 A g^(-1),and cycling stability of up to 98.6%after 10,000 cycles at a current density of 2 A g^(-1).The superior properties of ST-DDLGCs could be attributed to the unique porous tubular structure,which facilitated mass transfer and presented numerous active sites.The results highlight ST-DDLGCs as a potential candidate for constructing inexpensive and advanced environmentally functional materials and energy storage devices. 展开更多
关键词 Ganoderma lucidum residue Porous carbon nanotubes Self-template method Wastewater treatment Supercapacitor electrode
下载PDF
Electronic Communication Between Co and Ru Sites Decorated on Nitrogen-Doped Carbon Nanotubes Boosting the Alkaline Hydrogen Evolution Reaction
11
作者 Meng-Ting Gao Ying Wei +8 位作者 Xue-Meng Hu Wenj-Jie Zhu Qing-Qing Liu Jin-Yuan Qiang Wan-Wan Liu Ying Wang Xu Li Jian-Feng Huang Yong-Qiang Feng 《电化学(中英文)》 CAS 北大核心 2024年第9期1-9,共9页
Designing highly efficient Pt-free electrocatalysts with low overpotential for an alkaline hydrogen evolution reaction(HER)remains a significant challenge.Here,a novel and efficient cobalt(Co),ruthenium(Ru)bimetallic ... Designing highly efficient Pt-free electrocatalysts with low overpotential for an alkaline hydrogen evolution reaction(HER)remains a significant challenge.Here,a novel and efficient cobalt(Co),ruthenium(Ru)bimetallic electrocatalyst composed of CoRu nanoalloy decorated on the N-doped carbon nanotubes(CoRu@N-CNTs),was prepared by reacting fullerenol with melamine via hydrothermal treatment and followed by pyrolysis.Benefiting from the electronic communication between Co and Ru sites,the as-obtained CoRu@N-CNTs catalyst exhibited superior electrocatalytic HER activity.To deliver a current density of 10 mA·cm^(-2),it required an overpotential of merely 19 mV along with a Tafel slope of 26.19 mV·dec^(-1)in 1 mol·L^(-1)potassium hydroxide(KOH)solution,outperforming the benchmark Pt/C catalyst.The present work would pave a new way towards the design and construction of an efficient electrocatalyst for energy storage and conversion. 展开更多
关键词 CoRu alloy ELECTROCATALYST Water splitting Hydrogen evolution reaction carbon nanotubes
下载PDF
Nonlinear phenomena in vibrations of embedded carbon nanotubes conveying viscous fluid
12
作者 Reza Ebrahimi 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第1期44-54,共11页
Various nonlinear phenomena such as bifurcations and chaos in the responses of carbon nanotubes(CNTs)are recognized as being major contributors to the inaccuracy and instability of nanoscale mechanical systems.Therefo... Various nonlinear phenomena such as bifurcations and chaos in the responses of carbon nanotubes(CNTs)are recognized as being major contributors to the inaccuracy and instability of nanoscale mechanical systems.Therefore,the main purpose of this paper is to predict the nonlinear dynamic behavior of a CNT conveying viscousfluid and supported on a nonlinear elastic foundation.The proposed model is based on nonlocal Euler–Bernoulli beam theory.The Galerkin method and perturbation analysis are used to discretize the partial differential equation of motion and obtain the frequency-response equation,respectively.A detailed parametric study is reported into how the nonlocal parameter,foundation coefficients,fluid viscosity,and amplitude and frequency of the external force influence the nonlinear dynamics of the system.Subharmonic,quasi-periodic,and chaotic behaviors and hardening nonlinearity are revealed by means of the vibration time histories,frequency-response curves,bifurcation diagrams,phase portraits,power spectra,and Poincarémaps.Also,the results show that it is possible to eliminate irregular motion in the whole range of external force amplitude by selecting appropriate parameters. 展开更多
关键词 Nonlinear vibration carbon nanotubes Nonlocal effect Viscousfluid Nonlinear elastic medium
下载PDF
Hexagon-Islands Density and Size Distribution on Growing Single-Walled Carbon Nanotubes in the Kinetic 5-Vertex Model
13
作者 Sènan Ida Valérie Hontinfinde Josaphat Adda +2 位作者 Joel Kple Franck Zounmenou Félix Hontinfinde 《World Journal of Condensed Matter Physics》 CAS 2024年第4期77-95,共19页
A kinetic 5-vertex model is used to investigate hexagon-islands formation on growing single-walled carbon nanotubes (SWCNT). In the model, carbon atoms adsorption and migration processes on the SWCNT edge are consider... A kinetic 5-vertex model is used to investigate hexagon-islands formation on growing single-walled carbon nanotubes (SWCNT). In the model, carbon atoms adsorption and migration processes on the SWCNT edge are considered. These two dynamic processes are assumed to be mutually independent as well as mutually dependent as far as the whole growth of the nanotube is concerned. Key physical parameters of the model are the growth time t, the diffusion length Γ defined as the ratio of the diffusion rate D to the carbon atomic flux F and the SWCNT chiral angle. The kinetic equation that describes the nanotube edge dynamics is solved using kinetic Monte Carlo simulations with the Bortz, Kalos and Lebowitz update algorithm. The behaviors of islands density and size distribution are investigated within the growth parameters’ space. Our study revealed key mechanisms that enable the formation of a new ring of hexagons at the SWCNT edge. The growth occurs either by pre-existing steps propagation or by hexagon-islands growth and coalescence on terraces located between dislocation steps, depending on values of model parameters. This should offer a road map for edge design in nanotubes production. We also found that in appropriate growth conditions, the islands density follows Gaussian and generalized Wigner distributions whereas their size distribution at a given growth time shows a decreasing exponential trend. 展开更多
关键词 Kinetic 5-Vertex Model Single-Walled carbon nanotube Monte Carlo Simulations Island Density and Size Distribution Gaussian and Wigner Distributions
下载PDF
Study of the Diffusion Behavior of Seawater Absorption in Multi-Walled Carbon Nanotubes/Halloysite Nanotubes Hybrid Nanofillers Modified Epoxy-Based Glass/Carbon Fiber Composites
14
作者 Praful Choudhari Vivek Kulkarni Sanjeevakumar Khandal 《Modern Mechanical Engineering》 2024年第2期25-38,共14页
In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in har... In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients. 展开更多
关键词 Glass/carbon Fiber Hybrid Composites Multiwall carbon nanotubes (MWCNTs) Halloysite nanotubes (HNTs) Diffusion Behaviour Impact Properties Seawater Aging
下载PDF
The Influence of Carbon Nanotubes and Nano-Silica Fume on Enhancing the Damping and Mechanical Properties of Cement-Based Materials
15
作者 Bin Liu Norhaiza Nordin +2 位作者 Jiyang Wang Jingwei Wu Xiuliang Liu 《Materials Sciences and Applications》 2024年第9期399-416,共18页
This paper conducted experimental studies on the damping and mechanical properties of carbon nanotube-nanosilica-cement composite materials with different carbon nanotube contents. The damping and mechanical propertie... This paper conducted experimental studies on the damping and mechanical properties of carbon nanotube-nanosilica-cement composite materials with different carbon nanotube contents. The damping and mechanical properties enhancement mechanisms were analyzed and compared through the porosity structure test, XRD analysis, and scanning electron microscope observation. The results show that the introduction of nanosilica significantly improves the dispersion of carbon nanotubes in the cement matrix. At the same time, the addition of nanosilica not only effectively reduces the critical pore size and average pore size of the cement composite material, but also exhibits good synergistic effects with carbon nanotubes, which can significantly optimize the pore structure. Finally, a rationalization suggestion for the co-doping of nanosilica and carbon nanotubes was given to achieve a significant increase in the flexural strength, compressive strength and loss factor of cement-based materials. 展开更多
关键词 Cement-based Composites carbon nanotubes Nano Silica Fume Damping Property Mechanical Property
下载PDF
Selective glycerol oxidation using platinum nanoparticles supported on multi-walled carbon nanotubes and nitrogen-doped graphene hybrid 被引量:5
16
作者 张梦媛 孙妍妍 +2 位作者 石娟娟 宁文生 侯昭胤 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第3期537-544,共8页
Selective oxidation of glycerol is a hot topic.Increased biodiesel production has led to glycerol oxidation over Au- and Pt-based catalysts being widely studied.However,Pt catalysts suffer from deactivation because of... Selective oxidation of glycerol is a hot topic.Increased biodiesel production has led to glycerol oxidation over Au- and Pt-based catalysts being widely studied.However,Pt catalysts suffer from deactivation because of weak metal-support interactions.In this study,multi-walled carbon nanotube(MWCNTs)-pillared nitrogen-doped graphene(NG) was prepared by direct pyrolysis of melamine on MWCNTs,and the synthesized NG-MWCNT composite was used as the support for Pt.Characterization results showed that the surface area(173 m^2/g) and pore volume of the NG-MWCNT composite were greater than those of bare MWCNTs and the separated melamine pyrolysis product(CH_x).Pt(1.4±0.4 nm) dispersion on the NG-MWCNTs was favorable and the Pt/NG-MWCNT catalyst was highly active and selective in the oxidation of glycerol to glyceric acid(GLYA) in base-free aqueous solution.For example,the conversion of glycerol reached 64.4% with a GLYA selectivity of 81.0%,whereas the conversions of glycerol over Pt/MWCNTs and Pt/CN_x were 29.0% and 31.6%,respectively.The unique catalytic activity of the Pt/NG-MWCNTs is attributed to well-dispersed Pt clusters on the NG-MWCNTs and the electron-donating effect of the nitrogen dopant in the NG-MWCNTs. 展开更多
关键词 GLYCEROL Oxidation Pt carbon nanotube GRAPHENE
下载PDF
Influence of Pretreatment Conditions of Stainless Steel Substrates on Field Emission Properties of Carbon Nanotubes Films 被引量:4
17
作者 樊志琴 张兵临 +3 位作者 姚宁 鲁占灵 杨仕娥 马丙现 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2004年第11期1349-1354,共6页
Carbon nanotubes (CNTs) are synthesized from methane and hydrogen gas mixture directly on stainless steel plates by microwave plasma chemical vapor deposition (MWPCVD).By varying pretreatment conditions of the substra... Carbon nanotubes (CNTs) are synthesized from methane and hydrogen gas mixture directly on stainless steel plates by microwave plasma chemical vapor deposition (MWPCVD).By varying pretreatment conditions of the substrates such as mechanically polishing and acid washing,it is found the polishing and acid washing can lower the turn-on field and improve the emission current density.The current density of the un-pretreated sample attains 1.2mA/cm 2,but the polished sample and polished acidly washed sample attain 3.2 and 2.75mA/cm 2,respectively,at the electric field of 6.25V/μm. 展开更多
关键词 carbon nanotube MWPCVD field emission Raman spectroscopy
下载PDF
Enhanced thermal and electrical properties of poly (D,L-lactide)/ multi-walled carbon nanotubes composites by in-situ polymerization 被引量:5
18
作者 李清华 周勤华 +4 位作者 邓丹 俞巧珍 谷俐 龚科达 徐科航 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第5期1421-1427,共7页
Biodegradable poly (D,L-lactide) (PLA)/carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs) composites were achieved via in-situ polymerization. These as-prepared composite materials were characteriz... Biodegradable poly (D,L-lactide) (PLA)/carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs) composites were achieved via in-situ polymerization. These as-prepared composite materials were characterized with FT-IR, XRD, TG, DSC, SEM, and high insulation resistance meter. The results demonstrate that the multi-walled carbon nanotube was carboxyl functionalized, which improved the collection between c-MWCNTs and PLA, and further realized the graft copolymerization of c-MWCNTs and PLA. There is a higher glass transition temperature and a lower pyrolysis temperature of PLA/c-MWCNTs composites than pure PLA. The c-MWCNTs gave a better dispersion than unmodified MWCNTs in the PLA matrix, and an even coating of PLA on the surface of c-MWCNTs was obtained, which increased the interfacial interaction. High insulation resistance analysis showed that the addition of c-MWCNTs increased the electric conductivity, and c-MWCNTs performed against the large dielectric coefficient and electrostatic state of PLA. These results demonstrated that c-MWCNTs modified PLA composites were beneficial for potential application in the development of heat-resisting and conductivity plastic engineering. 展开更多
关键词 in-situ polymerization multi-walled carbon nanotubes POLYLACTIDE thermal properties electrical conductivity
下载PDF
Preparation and tribological performances of Ni-P-multi-walled carbon nanotubes composite coatings 被引量:7
19
作者 孟振强 李溪滨 +1 位作者 熊拥军 湛菁 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2719-2725,共7页
Multi-walled carbon nanotubes (MWNTs) were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribologi... Multi-walled carbon nanotubes (MWNTs) were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribological performances of the composite coatings under dry condition were investigated in comparison with 45 steel and conventional Ni-P coating, Micrographs show that short MWNTs with uniform length and open tips were obtained through the wet-milling process. The results of wear test reveal that the Ni-P-MWNTs composite coatings posses much better friction reduction and anti-wear performances when compared with 45 steel and Ni-P coating. Within the MWNTs content range of 0.74%-1.97%, the friction coefficient and the volume wear rate of the composite coatings decrease gradually and reach the minimum values of 0.08 and 6.22x10-15 m3/(N.m), respectively. The excellent tribological performances of the composite coatings can be attributed to the introduction of MWNTs, which play both roles of reinforcements and solid lubricant during the wear process. 展开更多
关键词 Ni-P coating carbon nanotubes composite coating ball milling electroless plating SELF-LUBRICATION tribologicalperformance friction coefficient volume wear rate
下载PDF
Fabrication of superaligned carbon nanotubes reinforced copper matrix laminar composite by electrodeposition 被引量:4
20
作者 靳宇 朱琳 +1 位作者 薛卫东 李文珍 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第9期2994-3001,共8页
A new kind of laminar metal matrix nanocomposite(MMC) was fabricated by an electrodeposition process with copper and superaligned carbon nanotubes film(SACNT film).The SACNT film was put on a titanium plate and th... A new kind of laminar metal matrix nanocomposite(MMC) was fabricated by an electrodeposition process with copper and superaligned carbon nanotubes film(SACNT film).The SACNT film was put on a titanium plate and then a layer of copper was electrodeposited on it.By repeating the above process,the laminar Cu/SACNT composite which contains dozens or hundreds of layers of copper and SACNT films was obtained.The thickness of a single copper layer was controlled by adjusting the process parameter easily and the thinnest layer is less than 2 μm.The microscopic observation shows that the directional alignment structure of SACNT is retained in the composite perfectly.The mechanical and electrical properties testing results show that the tensile and yield strengths of composites are improved obviously compared with those of pure copper,and the high conductivity is retained.This technology is a potential method to make applicable MMC which characterizes high volume fraction and directional alignment of carbon nanotubes. 展开更多
关键词 copper matrix laminar composite superaligned carbon nanotubes ELECTRODEPOSITION
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部