Journal articles: 'Nanotubes. Nanostructured materials. Carbon composites'

1

Loayza, Cristhian RL, Paulo DC Assunção, Danyella CS Cardoso, Diego JA Borges, Ademir AC Filho, Marcos AL Reis, and Eduardo M. Braga. "Incorporation of AWS 316L wire nanostructured with nickel-carbon nanotube by arc welding." Journal of Composite Materials 52, no. 14 (October 17, 2017): 1899–906. http://dx.doi.org/10.1177/0021998317735880.

Full text

Abstract:

Carbon nanotubes have certain properties, such as 150 GPa tensile strength, a 1000 GPa shear modulus, an electrical conductivity of 60 S/m, and a high thermal conductivity of 2500 W/mk, that make them an optimum metallic matrix composite reinforcement. Otherwise, arc welding is a common industrial process that joins almost all metals. However, there are hardly any studies involving the addition of carbon nanotubes in stainless steel so far. In this research, we show the incorporation of an AWS 316L nanostructured wire with nickel-carbon nanotubes in austenitic stainless steel via pulsed gas tungsten arc welding, which formed nanocomposites with 0.75 and 1.5 wt% carbon nanotube contents in the wire. The characterization was performed by scanning electronic microscope, Raman spectroscopy, and X-ray diffraction. The Vickers microhardness test was used to analyze the mechanical properties. The nanostructure composite had microstructure modification, and superficial microhardness improved in 35% for 0.75 wt% carbon nanotube.

APA, Harvard, Vancouver, ISO, and other styles

2

Lu, Shu-Nan, Ning Xie, Li-Chao Feng, and Jing Zhong. "Applications of Nanostructured Carbon Materials in Constructions: The State of the Art." Journal of Nanomaterials 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/807416.

Full text

Abstract:

The most recent studies on the applications of nanostructured carbon materials, including carbon nanotubes, carbon nanofibers, and graphene oxides, in constructions are presented. First, the preparation of nanostructured carbon/infrastructure material composites is summarized. This part is mainly focused on how the nanostructured carbon materials were mixed with cementitious or asphalt matrix to realize a good dispersion condition. Several methods, including high speed melting mixing, surface treatment, and aqueous solution with surfactants and sonication, were introduced. Second, the applications of the carbon nanostructured materials in constructions such as mechanical reinforcement, self-sensing detectors, self-heating element for deicing, and electromagnetic shielding component were systematically reviewed. This paper not only helps the readers understand the preparation process of the carbon nanostructured materials/infrastructure material composites but also sheds some light on the state-of-the-art applications of carbon nanostructured materials in constructions.

APA, Harvard, Vancouver, ISO, and other styles

3

Aida, Takuzo, and Takanori Fukushima. "Soft materials with graphitic nanostructures." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 365, no. 1855 (April 11, 2007): 1539–52. http://dx.doi.org/10.1098/rsta.2007.2030.

Full text

Abstract:

This review article focuses on our recent studies on novel soft materials consisting of carbon nanotubes. Single-walled carbon nanotubes, when suspended in imidazolium ion-based ionic liquids and ground in an agate mortar, form physical gels (bucky gels), where heavily entangled bundles of carbon nanotubes are exfoliated to give highly dispersed, much finer bundles. By using bucky gels, the first printable actuators that operate in air for a long time without any external electrolyte are developed. Furthermore, the use of polymerizable ionic liquids as the gelling media results in the formation of electroconductive polymer/nanotube composites with enhanced mechanical properties. The article also highlights a new family of nanotubular graphite, via self-assembly of amphiphilic hexabenzocoronene (HBC) derivatives. The nanotubes consist of a graphitic wall composed of a great number of π-stacked HBC units and are electroconductive upon oxidation. The use of amphiphilic HBCs with functional groups results in the formation of nanotubes with various interesting properties.

APA, Harvard, Vancouver, ISO, and other styles

4

Subramanian, V., Hongwei Zhu, and Bingqing Wei. "Nanostructured manganese oxides and their composites with carbon nanotubes as electrode materials for energy storage devices." Pure and Applied Chemistry 80, no. 11 (January 1, 2008): 2327–43. http://dx.doi.org/10.1351/pac200880112327.

Full text

Abstract:

Manganese oxides have been synthesized by a variety of techniques in different nanostructures and studied for their properties as electrode materials in two different storage applications, supercapacitors (SCs) and Li-ion batteries. The composites involving carbon nanotubes (CNTs) and manganese oxides were also prepared by a simple room-temperature method and evaluated as electrode materials in the above applications. The synthesis of nanostructured manganese oxides was carried out by simple soft chemical methods without any structure directing agents or surfactants. The prepared materials were well characterized using different analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), surface area studies, etc. The electrochemical properties of the nanostructured manganese oxides and their composites were studied using cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopic (EIS) studies. The influence of structural/surface properties on the electrochemical performance of the synthesized manganese oxides is reviewed.

APA, Harvard, Vancouver, ISO, and other styles

5

Loginos, Panagiotis, Anastasios Patsidis, and Vasilios Georgakilas. "UV-Cured Poly(Ethylene Glycol) Diacrylate/Carbon Nanostructure Thin Films. Preparation, Characterization, and Electrical Properties." Journal of Composites Science 4, no. 1 (January 1, 2020): 4. http://dx.doi.org/10.3390/jcs4010004.

Full text

Abstract:

Carbon nanoallotropes such as carbon nanotubes, graphene, and their derivatives have been combined with a plethora of polymers in the last years to develop new composite materials with interesting properties and applications. However, the area of photopolymer composites with carbon nanostructures has not been analogously explored. In the present article, we study the photopolymerization of poly(ethylene glycol)diacrylate (PEGDA) enriched with different carbon nanoallotropes like graphene, pristine and chemically modified carbon nanotubes (CNTs and fCNTs), and a hybrid of graphene and CNTs. The products were characterized by several microscopic and spectroscopic techniques and the electrical conductivity was studied as a function of the concentrations of carbon nanoallotropes. In general, stable thin films were produced with a concentration of carbon nanostructures up to 8.5%, although the addition of carbon nanostructures in PEGDA decreases the degree of photopolymerization, and PEDGA/carbon nanostructure composites showed electrical conductivity at a relatively low percentage.

APA, Harvard, Vancouver, ISO, and other styles

6

Комаров, Ф. Ф., И. Д. Парфимович, А. Г. Ткачев, А. В. Щегольков, О. В. Мильчанин, А. В. Щегольков, and В. Бондарев. "Влияние методов формирования полимерных композитных материалов с углеродными нанотрубками на механизмы электропроводности." Журнал технической физики 91, no. 3 (2021): 475. http://dx.doi.org/10.21883/jtf.2021.03.50526.222-20.

Full text

Abstract:

The influence of the method of formation of nanostructured polymer composites filled with carbon nanotubes to their electrophysical properties was carried out. The influence of the «size effect» of multi-walled carbon nanotubes, functionalization method, and ultrasonic treatment method on the electrical conductivity of composite materials in the frequency range 50 Hz - 5 MHz and the temperature range 15 - 375 K has been established. The presence of various mechanisms of electric transport in composite materials that affect the final value of electrical conductivity is established. The best results of electrophysical parameters are observed with a combination of non-covalent functionalization of nanotubes and high-power ultrasonic exposure. This method allows us to achieve a conductivity value of composite materials of 0.01 S/cm in the studied frequency range at a filler concentration of 0.5 wt.%.

APA, Harvard, Vancouver, ISO, and other styles

7

Yang, Yun Shik, Myeong Jun Kim, Young Chul Lee, and Si Tae Noh. "Conductive Property of Carbon-Nanotube Dispersed Nanocomposite Coatings for Steel." Solid State Phenomena 135 (February 2008): 35–38. http://dx.doi.org/10.4028/www.scientific.net/ssp.135.35.

Full text

Abstract:

Nanostructured modification of polymers has opened up new perspective for multifunctional materials. Carbon-nanotubes have the potential to increase the conductivity of their composite, with improved or retaining mechanical performance. This study focuses on the evaluation of the thermal and electrical conductivities of carbonnanotube filled alkyd resins for steel coatings. Polymer/Carbon-nanotube nanocomposites have been prepared by mixing commercial multiwall carbon-nanotubes with alkyd resins and by curing. The thermal and electrical conductivities of carbon-nanotubes filled nanocomposite was found to be increased comparing with the original resin without any fillers or with the resin with carbon-black or carbon-nanofiber.

APA, Harvard, Vancouver, ISO, and other styles

8

Koilraj, T. Thomas, and K. Kalaichelvan. "Hybrid Nanocomposites – A Review." Applied Mechanics and Materials 766-767 (June 2015): 50–56. http://dx.doi.org/10.4028/www.scientific.net/amm.766-767.50.

Full text

Abstract:

Since the last ten years, research happenings in the field of nanomaterials have been increased dramatically. Materials scientists and researchers have realized that the mechanical properties of materials can be altered at the fundamental level, i.e. at the atomic-scale. Carbon nanotubes have been well recognized as nanostructural materials that can be used to modify mechanical, thermal and electrical properties of polymer-based composite materials, because of their excellent properties and perfect atom arrangement. In geneal, scientific research related to the nanotubes and their co-related polymer based composites can be distinguished into four particular scopes: (i) production of high purity and well-regulated nanotubes, in terms of their size, length and chiral arrangement; (ii) enhancement of interfacial bonding strength between the nanotubes and their surrounding matrix; (iii) control of the dispersion properties and alignment of the nanotubes in nanotube/polymer composites and (iv) applications of the nanotube in real life. Research shows that addition of resin with nanoclays permits to retain stiffness without losing toughness, and also improving barrier and thermal properties. Dynamic Mechanical Analysis (DMA) studies revealed that filling the carbon nanotube into epoxy can produce a 90% enhancement in storage modulus and a 22°C increase in Tg. Addition of nanoclay and epoxy with nanotubes forms a hybrid nanocomposite.

APA, Harvard, Vancouver, ISO, and other styles

9

Rao, Apparao M., Xiaohua Ji, and Terry M. Tritt. "Properties of Nanostructured One-Dimensional and Composite Thermoelectric Materials." MRS Bulletin 31, no. 3 (March 2006): 218–23. http://dx.doi.org/10.1557/mrs2006.48.

Full text

Abstract:

AbstractOver a decade ago, Dresselhaus predicted that low-dimensional systems would one day serve as a route to enhanced thermoelectric performance.In this article, recent results in the thermoelectric properties of nanowires and nanotubes are discussed. Various synthesis techniques will be presented, including chemical vapor deposition for the growth of thermoelectric nanostructures in templated alumina.Electrical transport measurements of carbon nanostructures, such as resistivity and thermopower, have revealed some very interesting thermoelectric properties.Challenges still remain concerning the measurement of individual nanostructures such as nanowires.Much work has been performed on the thermoelectric properties of carbon nanotubes, and these results will be highlighted.In addition, routes for enhanced thermoelectric materials have focused on incorporating nanostructures within the bulk materials.The role of these “hybrid composite structures” based on nanomaterials incorporated into the bulk matrix and the potential for enhanced performance are discussed.

APA, Harvard, Vancouver, ISO, and other styles

10

Slepičková Kasálková, Nikola, Petr Slepička, and Václav Švorčík. "Carbon Nanostructures, Nanolayers, and Their Composites." Nanomaterials 11, no. 9 (September 12, 2021): 2368. http://dx.doi.org/10.3390/nano11092368.

Full text

Abstract:

The versatility of the arrangement of C atoms with the formation of different allotropes and phases has led to the discovery of several new structures with unique properties. Carbon nanomaterials are currently very attractive nanomaterials due to their unique physical, chemical, and biological properties. One of these is the development of superconductivity, for example, in graphite intercalated superconductors, single-walled carbon nanotubes, B-doped diamond, etc. Not only various forms of carbon materials but also carbon-related materials have aroused extraordinary theoretical and experimental interest. Hybrid carbon materials are good candidates for high current densities at low applied electric fields due to their negative electron affinity. The right combination of two different nanostructures, CNF or carbon nanotubes and nanoparticles, has led to some very interesting sensors with applications in electrochemical biosensors, biomolecules, and pharmaceutical compounds. Carbon materials have a number of unique properties. In order to increase their potential application and applicability in different industries and under different conditions, they are often combined with other types of material (most often polymers or metals). The resulting composite materials have significantly improved properties.

APA, Harvard, Vancouver, ISO, and other styles

11

Shchetinin, Y., Y. Kopylov, and A. Zhirkov. "The Effect of Surface Active Substances on the Mechanical Properties of a Copper-Matrix Nanocomposite." Materials Science Forum 945 (February 2019): 493–97. http://dx.doi.org/10.4028/www.scientific.net/msf.945.493.

Full text

Abstract:

The presented work reviews the research in the field of production of nanostructured composite materials based on copper, reinforced with carbon nanostructures. Particular attention is paid to the use of composites with high thermal conductivity as structural materials. The method of manufacturing a composite material based on copper is described in detail: modes of preliminary annealing, pre-pressing, hot isostatic pressing. The characteristics of the matrix and alloying components are given, and also preliminary treatment of copper powder and carbon nanotubes is described. Different mechanisms of component mixing are considered, the process of mechanical alloying in a planetary mill is described in detail, the results of measuring the thermal conductivity of samples are given. The mechanical characteristics of the samples are considered in detail: ultimate strength, yield strength, elongation. The degree of influence of surfactants on the uniformity of the distribution of alloying components and the mechanical properties of the composite material is determined.

APA, Harvard, Vancouver, ISO, and other styles

12

Song, Xiang-Yun, Wanqing Cao, Michael R. Ayers, and Arlon J. Hunt. "Carbon nanostructures in silica aerogel composites." Journal of Materials Research 10, no. 2 (February 1995): 251–54. http://dx.doi.org/10.1557/jmr.1995.0251.

Full text

Abstract:

A new method of preparing carbon nanotubes and their derivatives using silica aerogels as a matrix for the deposition of carbon is repeated. We present results of observations of graphite tubes and rings including nested structures in nanometer dimensions using high resolution transmission electron microscopy. Furthermore, we propose a model for the growth of carbon nanotubes in three steps including nucleation, growth, and closure of tubes.

APA, Harvard, Vancouver, ISO, and other styles

13

Le, Minh Tai, and Shyh Chour Huang. "Modeling and Analysis the Effect of Helical Carbon Nanotube Morphology on the Mechanical Properties of Nanocomposites Using Hexagonal Representative Volume Element." Applied Mechanics and Materials 577 (July 2014): 3–6. http://dx.doi.org/10.4028/www.scientific.net/amm.577.3.

Full text

Abstract:

Carbon nanotubes (CNTs) are the ultimate reinforcing materials for the development of an entirely new class of composites. However, they have the complicated shapes and do not usually appear as straight reinforcements when introduced in polymer matrices. This decreases nanotube’s effectiveness in enhancing the matrix mechanical properties. In this paper, nanostructure having hexagonal representative volume element (RVE), theory of elasticity of anisotropic materials and finite element method (FEM) are used to investigate the effect of helical CNT morphology on effective mechanical properties of nanocomposites. CNT with different helical angles are modeled to estimate the nanocomposite mechanical properties. The results of helical nanotube models are compared with the effective mechanical properties of nanocomposites reinforced with straight nanotubes.

APA, Harvard, Vancouver, ISO, and other styles

14

Raicopol, Matei, Alina Pruna, and Luisa Pilan. "Supercapacitance of Single-Walled Carbon Nanotubes-Polypyrrole Composites." Journal of Chemistry 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/367473.

Full text

Abstract:

The composites based on carbon nanotubes (CNTs) and conducting polymers (CPs) are promising materials for supercapacitor devices due to their unique nanostructure that combines the large pseudocapacitance of the CPs with the fast charging/discharging double-layer capacitance and excellent mechanical properties of the CNTs. Here, we report a new electrochemical method to obtain polypyrrole (PPY)/single-walled carbon nanotube (SWCNT) composites. In the first step, the SWCNTs are covalently functionalized with monomeric units of pyrrole by esterification of acyl chloride functionalized SWCNTs and N-(6-hydroxyhexyl)pyrrole. In the second step, the PPY/SWCNTs composites are obtained by copolymerizing the pyrrole monomer with the pyrrole units grafted on SWCNTs surface using controlled potential electrolysis. The composites were further characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The results showed good electrochemical charge storage properties for the synthesized composites based on PPY and SWCNTs covalently functionalized with pyrrole units making them promising electrode materials for high power supercapacitors.

APA, Harvard, Vancouver, ISO, and other styles

15

Cresta, Vanessa, Giuseppe Romano, Alexej Kolpak, Boštjan Zalar, and Valentina Domenici. "Nanostructured Composites Based on Liquid-Crystalline Elastomers." Polymers 10, no. 7 (July 14, 2018): 773. http://dx.doi.org/10.3390/polym10070773.

Full text

Abstract:

Liquid-crystalline elastomers (LCEs) are the object of many research investigations due to their reversible and controllable shape deformations, and their high potential for use in the field of soft robots and artificial muscles. This review focuses on recent studies about polymer composites based on LCEs and nanomaterials having different chemistry and morphology, with the aim of instilling new physical properties into LCEs. The synthesis, physico-chemical characterization, actuation properties, and applications of LCE-based composites reported in the literature are reviewed. Several cases are discussed: (1) the addition of various carbon nanomaterials to LCEs, from carbon black to carbon nanotubes, to the recent attempts to include graphene layers to enhance the thermo-mechanic properties of LCEs; (2) the use of various types of nanoparticles, such as ferroelectric ceramics, gold nanoparticles, conductive molybdenum-oxide nanowires, and magnetic iron-oxide nanoparticles, to induce electro-actuation, magnetic-actuation, or photo-actuation into the LCE-based composites; (3) the deposition on LCE surfaces of thin layers of conductive materials (i.e., conductive polymers and gold nanolayers) to produce bending actuation by applying on/off voltage cycles or surface-wrinkling phenomena in view of tunable optical applications. Some future perspectives of this field of soft materials conclude the review.

APA, Harvard, Vancouver, ISO, and other styles

16

Shchegolkov, A. V., A. V. Shchegolkov, F. F. Komarov, I. D. Parafimovich, O. O. Milchanin, and A. V. Kobelev. "The use of carbon nanotubes to create materials that absorb electromagnetic radiation and electrodes of supercapacitors." Proceedings of the Voronezh State University of Engineering Technologies 82, no. 1 (May 15, 2020): 267–72. http://dx.doi.org/10.20914/2310-1202-2020-1-267-272.

Full text

Abstract:

Carbon nanotubes are effective nanomodifiers – providing the formation of a variety of thermal and electrophysical properties in composite materials. The functional purpose of composite materials determines the type and concentration of carbon nanostructures. The use of carbon nanostructures in polymer composites intended for electromagnetic shielding and electrode materials of supercapacitors is a promising direction in modern materials science. The method of manufacturing a radio-absorbing composite material included impregnation of a polyurethane foam billet – an aqueous composite suspension consisting of water, an acrylic copolymer, and carbon nanotubes "Taunit-MD". Structural studies of carbon nanotube samples were performed using transmission and scanning electron microscopy. To do this, PAM and SAM studies were performed using a HitachiH-800 electron microscope with an accelerating voltage of up to 200 Kev. For research purposes, electrodes with an area of 2 cm2 were made from carbon materials. Active mass was prepared from a carbon material and a binder, polivinildenftorid. Show PEM and SAM micrographs for samples of carbon nanotubes with the commercial name "Taunit-M". In this case, carbon nanotubes are characterized by smaller thicknesses in the range of 10-20 nm with a preferred average size of 12-15 nm. The structure of the tubes is very defective. The thickness of the tubes varies in some areas (not exceeding hundreds of nm) by more than 2 times. Carbon nanotubes have an irregular shape-there are processes, bends. The analysis of the obtained results allows us to conclude that the characteristic of the reflected EMI signal demonstrated by the pyramidal RPM is close in its values to that of the free space. At the same time, in comparison with the free space, there is a slight weakening (3-4) dB of the reflection coefficient. Carbon nanotubes MD has characteristics that exceed the carbon fabric "busofit" in terms of specific mass capacity, but inferior to it in terms of specific surface capacity. In addition, this advantage completely disappears at high current densities, which may be the result of a closed macrostructure and requires further optimization of the electrode manufacturing technology

APA, Harvard, Vancouver, ISO, and other styles

17

Zhang, Lingxia, Jianlin Shi, Jiangtian Li, Zile Hua, and Meiling Ruan. "Carbon nanostructures formed on mesoporous silica by catalytic chemical vapor deposition of ethene." Journal of Materials Research 23, no. 2 (February 2008): 435–43. http://dx.doi.org/10.1557/jmr.2008.0047.

Full text

Abstract:

Three different strategies, wet impregnation, in situ reduction, and grafting with silane coupling agents, have been used to introduce CoNi nanoparticles with different existing forms into mesoporous silica. These composites were used as catalysts to grow nanostructured carbons by catalytic chemical vapor deposition using ethene. Carbon nanotubes (CNTs) with different inner diameters can grow out of mesoporous silica particles incorporated with CoNi nanoclusters. Many fewer CNTs could be found in the pore channels of the sample prepared by using silane coupling agents than in those of the sample synthesized via wet impregnation. No CNTs formed in the pore channels of the sample prepared by in situ reduction. After the removal of silica, different carbon nanostructures have been obtained in the pore channels. Ordered graphite carbon mesostructure was obtained from the sample prepared by in situ reduction. Highly dispersed metal catalysts inside mesopore channels are favorable for the formation of graphite carbons with ordered mesostructures.

APA, Harvard, Vancouver, ISO, and other styles

18

Ali, Asar, Adam Khan, Kh S. Karimov, Amjad Ali, and Adnan Daud Khan. "Pressure Sensitive Sensors Based on Carbon Nanotubes, Graphene, and Its Composites." Journal of Nanomaterials 2018 (2018): 1–12. http://dx.doi.org/10.1155/2018/9592610.

Full text

Abstract:

Carbon nanotubes (CNTs) and graphene have attracted a great deal of interest due to their outstanding mechanical, optical, electrical, and structural properties. Most of the scientists and researchers have investigated the optical and electrical properties of these materials. However, due to unique electromechanical properties of these materials, it is required to explore the piezoresistive properties of bulk nanostructured CNTs, graphene, and CNT-graphene composites. We investigated and compared the sensitivities and piezoresistive properties of sandwich-type pure CNT, pure graphene, and CNT-graphene composite pressure sensors. For all the samples, increase in pressure from 0 to 0.183 kNm−2 results in a decrease in the impedance and direct current (DC) resistance. Sensitivity and percentage decrease in resistance and impedance of CNT-graphene composite were lower than pure CNT while being higher than pure graphene based sample. Moreover, under the same external applied pressure, the sensitivity and percentage decrease in impedance for pure CNT, pure graphene, and CNT-graphene composite were smaller than the corresponding sensitivity and percentage decrease in resistance. The achieved experimental results of the composite sample were compared with simulated results which exhibit reasonable agreement with each other. The deviations of simulated resistance-pressure and impedance-pressure curves from experimental graphs were 0.029% and 0.105%, respectively.

APA, Harvard, Vancouver, ISO, and other styles

19

Haddadi, Manel, Boudjemaa Agoudjil, and Abderrahim Boudenne. "Thermal Conductivity of Polymer/Carbon Nanotube Composites." Materials Science Forum 714 (March 2012): 99–113. http://dx.doi.org/10.4028/www.scientific.net/msf.714.99.

Full text

Abstract:

As one of the most important field of current nanoscience, the polymer nanocomposites is a promising and efficient way for new generation materials with high performances and multifunctionalities. The incorporating of nanofillers in a polymer matrix may improve mechanical, thermal, electrical or dielectric properties of the composites. The current paper focuses on the thermal conductivity of polymer/carbon nanotube composites. These last, are considered to be ideal candidates for the development of nanocomposite materials. Clarifying the role of the factors, influencing the properties of the composites, enable us to choose the suitable processing method for obtaining the composites and to improve the different properties of these systems. This article reviews the dependence of thermal conductivity of carbon nanotubes on the tube size and the effect of interface on the equivalent property. The relationship between the thermal conductivity and the nanostructure of composites are discussed.

APA, Harvard, Vancouver, ISO, and other styles

20

Liu, Lei, Chang-Ce Ke, Tian-Yi Ma, and Yun-Pei Zhu. "When Carbon Meets CO2: Functional Carbon Nanostructures for CO2 Utilization." Journal of Nanoscience and Nanotechnology 19, no. 6 (June 1, 2019): 3148–61. http://dx.doi.org/10.1166/jnn.2019.16590.

Full text

Abstract:

Major fossil fuel consumption associated with CO2 emission and socioeconomic instability has received much concern within the global community regarding the long-term sustainability and security of these commodities. The capture, sequestration, and conversion of CO2 emissions from flue gas are now becoming familiar worldwide. Nanostructured carbonaceous materials with designed functionality have been extensively used in some key CO2 exploitation processes and techniques, because of their excellent electrical conductivity, chemical/mechanical stability, adjustable chemical compositions, and abundant active sites. This review focuses on a variety of carbonaceous materials, like graphene, carbon nanotubes, amorphous porous carbons and carbon hybrid composites, which have been demonstrated promising in CO2 capture/separation and conversion (electrocatalysis and photocatalysis) to produce value-added chemicals and fuels. Along with the discussion and concerning synthesis strategies, characterization and conversion and capture/separation techniques employed, we further elaborate the structure-performance relationships in terms of elucidating active sites, reaction mechanisms and kinetics improvement. Finally, challenges and future perspectives of these carbon-based materials for CO2 applications using well-structured carbons are remarked in detail.

APA, Harvard, Vancouver, ISO, and other styles

21

Malik, Sharali, Yoshihiro Nemoto, Hongxuan Guo, Katsuhiko Ariga, and Jonathan P. Hill. "Fabrication and characterization of branched carbon nanostructures." Beilstein Journal of Nanotechnology 7 (September 5, 2016): 1260–66. http://dx.doi.org/10.3762/bjnano.7.116.

Full text

Abstract:

Carbon nanotubes (CNTs) have atomically smooth surfaces and tend not to form covalent bonds with composite matrix materials. Thus, it is the magnitude of the CNT/fiber interfacial strength that limits the amount of nanomechanical interlocking when using conventional CNTs to improve the structural behavior of composite materials through reinforcement. This arises from two well-known, long standing problems in this research field: (a) inhomogeneous dispersion of the filler, which can lead to aggregation and (b) insufficient reinforcement arising from bonding interactions between the filler and the matrix. These dispersion and reinforcement issues could be addressed by using branched multiwalled carbon nanotubes (b-MWCNTs) as it is known that branched fibers can greatly enhance interfacial bonding and dispersability. Therefore, the use of b-MWCNTs would lead to improved mechanical performance and, in the case of conductive composites, improved electrical performance if the CNT filler was better dispersed and connected. This will provide major benefits to the existing commercial application of CNT-reinforced composites in electrostatic discharge materials (ESD): There would be also potential usage for energy conversion, e.g., in supercapacitors, solar cells and Li-ion batteries. However, the limited availability of b-MWCNTs has, to date, restricted their use in such technological applications. Herein, we report an inexpensive and simple method to fabricate large amounts of branched-MWCNTs, which opens the door to a multitude of possible applications.

APA, Harvard, Vancouver, ISO, and other styles

22

Arrigo, Rossella, and Giulio Malucelli. "Rheological Behavior of Polymer/Carbon Nanotube Composites: An Overview." Materials 13, no. 12 (June 18, 2020): 2771. http://dx.doi.org/10.3390/ma13122771.

Full text

Abstract:

This paper reviews the current achievements regarding the rheological behavior of polymer-based nanocomposites containing carbon nanotubes (CNTs). These systems have been the subject of a very large number of scientific investigations in the last decades, due to the outstanding characteristics of CNTs that have allowed the formulation of nanostructured polymer-based materials with superior properties. However, the exploitation of the theoretical nanocomposite properties is strictly dependent on the complete dispersion of CNTs within the host matrix and on the consequent development of a huge interfacial region. In this context, a deep knowledge of the rheological behavior of CNT-containing systems is of fundamental importance, since the evaluation of the material’s viscoelastic properties allows the gaining of fundamental information as far as the microstructure of nanofilled polymers is concerned. More specifically, the understanding of the rheological response of polymer/CNT nanocomposites reveals important details about the characteristics of the interface and the extent of interaction between the two components, hence allowing the optimization of the final properties in the resulting nanocomposites. As the literature contains plenty of reviews concerning the rheological behavior of polymer/CNT nanocomposites, this review paper will summarize the most significant thermoplastic matrices in terms of availability and relevant industrial applications.

APA, Harvard, Vancouver, ISO, and other styles

23

Le, Minh Tai, and Shyh Chour Huang. "Hexagonal Representative Volume Element for Modeling and Analysis of Mechanical Properties of Carbon Nanotube Reinforced Composites." Applied Mechanics and Materials 496-500 (January 2014): 251–54. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.251.

Full text

Abstract:

Carbon nanotubes (CNTs) possess extremely high stiffness, strength and resilience, and may provide the ultimate reinforcing materials for the development of nanocomposites. In this paper, nanostructure is modeled as a linearly elastic composite medium, which consists of a homogeneous matrix having hexagonal representative volume elements (RVEs) and homogeneous cylindrical nanotubes. Formulas to extract the effective material constants from solutions for the RVE under axial as well as lateral loading conditions are derived based on the continuum mechanics approach. Numerical examples using the FEM are presented, which demonstrate that the load carrying capacities of the CNTs in a matrix are significant. For the RVEs having long carbon nanotube, better values of stiffness in axial direction are found as compared to stiffness in the lateral direction. Also, It is found that the square RVEs tend to overestimate the effective Youngs moduli of the CNT-based composites, and the hexagonal RVEs may be the preferred models for obtaining more accurate results.

APA, Harvard, Vancouver, ISO, and other styles

24

Fisher, Caitlin, Amanda E. Rider, Zhao Jun Han, Shailesh Kumar, Igor Levchenko, and Kostya (Ken) Ostrikov. "Applications and Nanotoxicity of Carbon Nanotubes and Graphene in Biomedicine." Journal of Nanomaterials 2012 (2012): 1–19. http://dx.doi.org/10.1155/2012/315185.

Full text

Abstract:

Owing to their unique mechanical, electrical, optical, and thermal properties, carbon nanostructures including carbon nanotubes and graphenes show great promise for advancing the fields of biology and medicine. Many reports have demonstrated the promise of these carbon nanostructures and their hybrid structures (composites with polymers, ceramics, and metal nanoparticles, etc.) for a variety of biomedical areas ranging from biosensing, drug delivery, and diagnostics, to cancer treatment, tissue engineering, and bioterrorism prevention. However, the issue of the safety and toxicity of these carbon nanostructures, which is vital to their use as diagnostic and therapeutic tools in biomedical fields, has not been completely resolved. This paper aims to provide a summary of the features of carbon nanotube and graphene-based materials and current research progress in biomedical applications. We also highlight the current opinions within the scientific community on the toxicity and safety of these carbon structures.

APA, Harvard, Vancouver, ISO, and other styles

25

Silva, Valdirene Aparecida, Luiza de Castro Folgueras, Geraldo Maurício Cândido, Adriano Luiz de Paula, Mirabel Cerqueira Rezende, and Michelle Leali Costa. "Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials." Materials Research 16, no. 6 (September 3, 2013): 1299–308. http://dx.doi.org/10.1590/s1516-14392013005000146.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Yin, Jingtian, Masashi Wada, Yasuyuki Kitano, Shigeo Tanase, Osamu Kajita, and Tetsuo Sakai. "Nanostructured Ag–Fe–Sn/Carbon Nanotubes Composites as Anode Materials for Advanced Lithium-Ion Batteries." Journal of The Electrochemical Society 152, no. 7 (2005): A1341. http://dx.doi.org/10.1149/1.1921727.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Al-Haik, M., C. C. Luhrs, M. M. Reda Taha, A. K. Roy, L. Dai, J. Phillips, and S. Doorn. "Hybrid Carbon Fibers/Carbon Nanotubes Structures for Next Generation Polymeric Composites." Journal of Nanotechnology 2010 (2010): 1–9. http://dx.doi.org/10.1155/2010/860178.

Full text

Abstract:

Pitch-based carbon fibers are commonly used to produce polymeric carbon fiber structural composites. Several investigations have reported different methods for dispersing and subsequently aligning carbon nanotubes (CNTs) as a filler to reinforce polymer matrix. The significant difficulty in dispersing CNTs suggested the controlled-growth of CNTs on surfaces where they are needed. Here we compare between two techniques for depositing the catalyst iron used toward growing CNTs on pitch-based carbon fiber surfaces. Electrochemical deposition of iron using pulse voltametry is compared to DC magnetron iron sputtering. Carbon nanostructures growth was performed using a thermal CVD system. Characterization for comparison between both techniques was compared via SEM, TEM, and Raman spectroscopy analysis. It is shown that while both techniques were successful to grow CNTs on the carbon fiber surfaces, iron sputtering technique was capable of producing more uniform distribution of iron catalyst and thus multiwall carbon nanotubes (MWCNTs) compared to MWCNTs grown using the electrochemical deposition of iron.

APA, Harvard, Vancouver, ISO, and other styles

28

Avila, Antonio, Viviane Munhoz, Aline Oliveira, and Elvis Monteiro. "Carbon Based Nanostructures Hybrids for Composites Materials: The Graphene—Carbon Nanotubes Interaction Investigation." Journal of Multifunctional Composites 2, no. 4 (2014): 195–206. http://dx.doi.org/10.12783/issn.2168-4286/2.4/avila.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Golovin, Yu I., A. I. Tyurin, V. V. Korenkov, V. V. Rodaev, A. O. Zhigachev, A. V. Umrikhin, T. S. Pirozhkova, and S. S. Razlivalova. "Effect of Carbon Nanotubes on Strength Characteristics of Nanostructured Ceramic Composites for Biomedicine." Nanotechnologies in Russia 13, no. 3-4 (March 2018): 168–72. http://dx.doi.org/10.1134/s1995078018020039.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Larrude, Dunieskys G., Marcelo E. H. Maia da Costa, and Fernando L. Freire. "Synthesis and Characterization of Silver Nanoparticle-Multiwalled Carbon Nanotube Composites." Journal of Nanomaterials 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/654068.

Full text

Abstract:

Multiwalled carbon nanotubes (MWCNTs) grown by spray pyrolysis have been decorated with silver nanoparticles prepared via the silver mirror reaction. Good dispersion of silver nanostructures was obtained on the surface of MWCNTs, resulting in an efficient and simple wet chemistry method for increasing the reactivity of the carbon nanotubes surfaces. High-resolution transmission electron microscopy showed the orientations of the crystallography planes of the anchored silver nanoparticles and revealed their size distribution. Raman spectroscopy results confirm that the composite material preserves the integrity of the MWCNTs. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were also employed for sample characterization.

APA, Harvard, Vancouver, ISO, and other styles

31

Manikandan, P., R. Sieh, A. Elayaperumal, H. R. Le, and S. Basu. "Micro/Nanostructure and Tribological Characteristics of Pressureless Sintered Carbon Nanotubes Reinforced Aluminium Matrix Composites." Journal of Nanomaterials 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/9843019.

Full text

Abstract:

This study reports the manufacture, microstructure, and tribological behaviour of carbon nanotube reinforced aluminium composites against pure aluminium. The specimens were fabricated using powder metallurgy method. The nanotubes in weight percentages of 0.5, 1.0, 1.5, and 2.0 were homogeneously dispersed and mechanically alloyed using a high energy ball milling. The milled powders were cold compacted and then isothermally sintered in air. The density of all samples was measured using Archimedes method and all had a relative density between 92.22% and 97.74%. Vickers hardness increased with increasing CNT fraction up to 1.5 wt% and then reduced. The microstructures and surfaces were investigated using high resolution scanning electron microscope (SEM). The tribological tests showed that the CNT reinforced composites displayed lower wear rate and friction coefficient compared to the pure aluminium under mild wear conditions. However, for severe wear conditions, the CNT reinforced composites exhibited higher friction coefficient and wear rate compared to the pure aluminium. It was also found that the friction and wear behaviour of CNT reinforced composites is significantly dependent on the applied load and there is a critical load beyond which CNTs could have adverse impact on the wear resistance of aluminium.

APA, Harvard, Vancouver, ISO, and other styles

32

Zhao, Zehao, Zirui Jia, Hongjing Wu, Zhenguo Gao, Yi Zhang, Kaichang Kou, Zhengyong Huang, Ailing Feng, and Guanglei Wu. "Morphology-dependent electromagnetic wave absorbing properties of iron-based absorbers: one-dimensional, two-dimensional, and three-dimensional classification." European Physical Journal Applied Physics 87, no. 2 (August 2019): 20901. http://dx.doi.org/10.1051/epjap/2019190171.

Full text

Abstract:

Owing to the fast development of wireless techniques at the high-frequency range, the electromagnetic interference problem has been of increasing significance and attracting global attention. It is urgent to develop efficient microwave absorbing materials to attenuate the harmful electromagnetic wave. Iron and Fe-based composites are advantageous in the low-cost and attractive magnetic properties, so they have been widely studied in microwave absorption. This review focuses on the latest advances in nanostructured Fe-based materials including nanostructured iron, Fe/C (carbon nanotubes, nanofibers, nanocapsules, etc.), Fe/semiconductor (TiO2, MnO2, ZnO, SiO2, MoS2, etc.), Fe/polymer (polyaniline and polypyrrole), FeCo alloy, etc. However, most of these Fe-based materials suffer from the poor impedance matching and oxidation, which seriously impede their implementation as high-performance microwave absorbing materials. In this review, the main synthesis and modification methods, as well as the practical performance of Fe-based microwave absorbing materials are discussed. Moreover, challenges and perspectives of Fe-based composites for further development in microwave absorbing materials are proposed.

APA, Harvard, Vancouver, ISO, and other styles

33

Candelario, Victor M., Rodrigo Moreno, Fernando Guiberteau, and Angel L. Ortiz. "Enhancing the sliding-wear resistance of SiC nanostructured ceramics by adding carbon nanotubes." Journal of the European Ceramic Society 36, no. 13 (October 2016): 3083–89. http://dx.doi.org/10.1016/j.jeurceramsoc.2016.05.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Gerasimenko, Alexander Yu, and Dmitry I. Ryabkin. "Структурные и спектральные особенности композитов на основе белковых сред с одностенными углеродными нанотрубоками." Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 21, no. 2 (June 14, 2019): 191–203. http://dx.doi.org/10.17308/kcmf.2019.21/757.

Full text

Abstract:

Исследованы структурные особенности нанокомпозитов, полученных при лазерном облучении водно-белковых сред с одностенными углеродными нанотрубками (ОУНТ), электродуговым (ОУНТI) и газофазным методами (ОУНТII). С помощью спектроскопии комбинационного рассеяния нанокомпозитов определен нековалентный характер взаимодействия нанотрубок с молекулами белков. Белковая составляющая в нанокомпозитах подверглась необратимой денатурации и может выступать в качестве связующего биосовместимого материала, который является источником аминокислот для биологических тканей при имплантации нанокомпозитов в организм. Образцы, изготовленные из ОУНТI, с меньшим диаметром и длиной имели наиболее однородную структуру. При увеличении концентрации от 0.01 до 0.1 % происходило увеличение среднего размерамикропор от 45 до 85 мкм и пористости образца в общем с 46 до 58 %. При этом доля открытых пор для двух типов концентраций ОУНТI составила 2 % от общего объема композита. В нанокомпозитах на основе ОУНТI показано наличие мезопор. Увеличение концентрации нанотрубок привело к уменьшению удельных значений поверхности и объема пор образца. Исследованные нанокомпозиты могут использоваться в качестве тканеинженерных матриц для восстановления объемных дефектов биологических тканей REFERENCES Eletskii A. V. Carbon nanotubes. Usp., 1997, v. 40(9), pp. 899–924. https://dji.org/10.1070/PU1997v040n09ABEH000282 Tuchin A. V., Tyapkina V. A., Bityutskaya L. A., Bormontov E. N. Functionalization of capped ultrashort single-walled carbon nanotube (5, 5). Condensed matter and interphases, 2016, v. 18(4), pp. 568–577. URL: http://www.kcmf.vsu.ru/resources/t_18_4_2016_015.pdf (in Russ.) Dolgikh I., Tyapkina V. A., Kovaleva T. A., Bityutskaya L. A. 3D Topological changes in enzyme glucoamylase when immobilized on ulrta0short carbon naotubes. Condensed matter and interphases, 2016, v. 18(4), pp. 505–512. URL: http://www.kcmf.vsu.ru/resources/t_18_4_2016_007.pdf (in Russ.) Kulikova T. V., Tuchin A. V., Testov D. A., Bityutskaya L. A., Bormontov E. N., Averin A. A. Structure and properties of self-organized 2D and 3D antimony/carbon composites. Technical Physics, 2018, v. 63(7), pp. 995–1001. https://doi.org/10.1134/S1063784218070216 Kulikova T. V., Bityutskaya L. A., Tuchin A. V., Lisov E. V., Nesterov S. I., Averin A. A., Agapov B. L. Structural heterogeneities and electronic effects in self-organized core-shell type structures of Sb. Letters on materials, 2017, v. 7(4), pp. 350–354. https://doi.org/10.22226/2410-3535-2017-4-350-354 Gerasimenko A. Yu. Laser structuring of the carbon nanotubes ensemble intended to form biocompatible ordered composite materials. Condensed matter and interphases, 2017, v. 19(4), pp. 489–501. https://doi.org/10.17308/kcmf.2017.19/227 Ma R. Z., Wei B. Q., Xu C. L., Liang J., Wu D. H. The morphology changes of carbon nanotubes under laser irradiation. Carbon, 2000, vol. 38(4), pp. 636–638. https://doi.org/10.1016/s0008-6223(00)00008-7 Sadeghpour H. R., Brian E. Interaction of laser light and electrons with nanotubes. Physica Scripta, 2004, vol. 110, pp. 262–267. https://doi.org/10.1238/physica. topical.110a00262 Gyorgy E., Perez del Pino A., Roqueta J., Ballesteros B., Cabana L., Tobias G. Effect of laser radiation on multi-wall carbon nanotubes: study of shell structure and immobilization process. of Nanoparticle Research, 2013, v. 15(8), p. 1852. https://doi.org/10.1007/s11051-013-1852-6 Krasheninnikov A. V., Banhart F. Engineering of nanostructured carbon materials with electron or ion beams. Nature Materials, 2007, v. 6(10), pp. 723–733. https://doi.org/10.1038/nmat1996 Ogihara N., Usui Y., Aoki K., Shimizu M., Narita N., Hara K., Nakamura K., Ishigaki N., Takanashi S., Okamoto M., Kato H., Haniu H., Ogiwara N., Nakayama N., Taruta S., Saito N. Biocompatibility and bone tissue compatibility of alumina ceramics reinforced with carbon nanotubes. Nanomedicine, 2012, v. 7(7), pp. 981–993. https://doi.org/10.2217/nnm.12.1 Abarrategi A., Gutiérrez M.C., Moreno-Vicente C., Hortigüela M. J., Ramos V., Lуpez-Lacomba J. L., Ferrer M. L., del Monte F. Multiwall carbon nanotube scaffolds for tissue engineering purposes. Biomaterials, 2008, v. 29(1), pp. 94–102. https://doi.org/10.1016/j.biomaterials.2007.09.021 Newman P., Minett A., Ellis-Behnke R., Zreiqat H. Carbon nanotubes: Their potential and pitfalls for bone tissue regeneration and engineering. Nanomedicine, 2013, v. 9(8), pp. 1139–1158. https://doi.org/10.1016/j.nano.2013.06.001 Sahithi K., Swetha M., Ramasamy K., Selvamurugan N. Polymeric composites containing carbon nanotubes for bone tissue engineering. International journal of biological macromolecules, 2010, v. 46(3). pp. 281–283. https://doi.org/10.1016/j.ijbiomac.2010.01.006 Pan L., Pei, He R., Wan Q., Wang J. Colloids and Surfaces B: Biointerfaces, 2012, vol. 93, pp. 226–234. https://doi.org/10.1016/j.colsurfb.2012.01.011 Mattioli-Belmonte M., Vozzi G, Whulanza Y., Seggiani M., Fantauzzi V., Orsini G., Ahluwalia A. Tuning polycaprolactone–carbon nanotube composites for bone tissue engineering scaffolds. Materials Science and Engineering: C, 2012, v. 32(2), pp. 152–159. https://doi.org/10.1016/j.msec.2011.10.010 Venkatesan J., Qian Z., Ryu B., Kumar N.A., Kim S. Preparation and characterization of carbon nanotube-grafted-chitosan – Natural hydroxyapatite composite for bone tissue engineering. Carbohydrate Polymers, 2011, v. 83(2). pp. 569–577. https://doi.org/10.1016/j.carbpol.2010.08.019 Lin C., Wang Y., Lai Y., Yang W., Jiao F., Zhang H., Shefang Ye., Zhang Q. Incorporation of carboxylation multiwalled carbon nanotubes into biodegradable poly(lactic-co-glycolic acid) for bone tissue engineering. Colloids and Surfaces B: Biointerfaces, 2011, v. 83(2), pp. 367–375. https://doi.org/10.1016/j.colsurfb.2010.12.011 Gerasimenko A. Yu. , Glukhova O. E., Savostyanov G. V., Podgaetsky V. M. Laser structuring of carbon nanotubes in the albumin matrix for the creation of composite biostructures. Journal of Biomedical Optics, 2017, v. 22(6), pp. 065003-1–065003-8. https://doi.org/10.1117/1.jbo.22.6.065003

APA, Harvard, Vancouver, ISO, and other styles

35

Islam, Rakibul, Anthony N. Papathanassiou, Roch Chan-Yu-King, Carole Gors, and Frédérick Roussel. "Competing charge trapping and percolation in core-shell single wall carbon nanotubes/ polyaniline nanostructured composites." Synthetic Metals 259 (January 2020): 116259. http://dx.doi.org/10.1016/j.synthmet.2019.116259.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Karaxi, Evangelia K., Irene A. Kanellopoulou, Anna Karatza, Ioannis A. Kartsonakis, and Costas A. Charitidis. "Fabrication of carbon nanotube-reinforced mortar specimens: evaluation of mechanical and pressure-sensitive properties." MATEC Web of Conferences 188 (2018): 01019. http://dx.doi.org/10.1051/matecconf/201818801019.

Full text

Abstract:

Carbon-based nanomaterials are promising reinforcing elements for the development of “smart” self-sensing cementitious composites due to their exceptional mechanical and electrical properties. Significant research efforts have been committed on the synthesis of cement-based composite materials reinforced with carbonaceous nanostructures, covering every aspect of the production process (type of nanomaterial, mixing process, electrode type, measurement methods etc.). In this study, the aim is to develop a well-defined repeatable procedure for the fabrication as well as the evaluation of pressure-sensitive properties of intrinsically self-sensing cementitious composites incorporating carbon- based nanomaterials. Highly functionalized multi-walled carbon nanotubes with increased dispersibility in polar media were used in the development of advanced reinforced mortar specimens which increased their mechanical properties and provided repeatable pressure-sensitive properties.

APA, Harvard, Vancouver, ISO, and other styles

37

Iqbal, Muhammad, Embun Marintan, Ni Luh Wulan Septiani, Suyatman, Ahmad Nuruddin, Nugraha, and Brian Yuliarto. "Synthesis and Harmful Gas Sensing Properties of Zinc Oxide Modified Multi-Walled Carbon Nanotubes Composites." Advanced Materials Research 1044-1045 (October 2014): 172–75. http://dx.doi.org/10.4028/www.scientific.net/amr.1044-1045.172.

Full text

Abstract:

Metal oxide semiconductors materials such as zinc oxide (ZnO) are often used in the fabrication of chemoresistive gas sensors, but ZnO materials require high operating temperatures to operate. In another side, carbon nanotubes (CNT) have many distinct properties and recently have been exploited as the next generation of sensors, including chemoresisitive type gas sensors. This study was aimed to investigate the performance of MWNT-ZnO composites as SO2 gas sensitive layer. By fabricate composites of MWNT and ZnO, have been obtained a sensitive layer that can be utilized for application as gas sensitive layer with relatively lower operating temperature. A sensitive layer of MWNT-ZnO based composites have been successfully fabricated on a alumina substrate and several characterization techniques has been performed, i.e. XRD, SEM and EDS to study the formed crystalline phase, the morphology of the nanostructures, and the elemental composition of synthesized composites. MWNT-ZnO sensitive layer was tested by exposure to SO2 gas at various operating temperatures and gas concentration. From the performance testing results, it could be found that the composite materials have a prospective as a gas sensor at lower operating temperature with short response time and good sensitivity.

APA, Harvard, Vancouver, ISO, and other styles

38

Galimberti, Maurizio, Valeria Cipolletti, Sara Musto, Serena Cioppa, Giulia Peli, Marco Mauro, Guerra Gaetano, Silvia Agnelli, Riccò Theonis, and Vineet Kumar. "RECENT ADVANCEMENTS IN RUBBER NANOCOMPOSITES." Rubber Chemistry and Technology 87, no. 3 (September 1, 2014): 417–42. http://dx.doi.org/10.5254/rct.14.86919.

Full text

Abstract:

ABSTRACT Nanocomposites were prepared via melt blending, based on organically modified clays (OC), carbon nanotubes (CNT), and graphitic nanofillers made by a few layers of graphene (nanoG). In particular, nanocomposites based on a hybrid filler system, with a nanostructured filler such as carbon black (CB), are examined. It is shown that low crystalline order in the interlayer space of a layered nanofiller (such as OC and nanoG) leads to easier delamination. Nanofillers give rise to filler networking at low concentration, particularly in the presence of CB. Hybrid filler systems lead to nanocomposites' having initial moduli that are much higher than those calculated through the sum of the initial modulus of composites containing either only CB or only the nanofiller. Nanofillers enhance the matrix modulus by a multiplication factor that depends only on the nanofiller type and content, regardless of whether the matrix is a neat or a CB-filled polymer. Furthermore, the filler–polymer interfacial area is shown to be a parameter able to correlate the mechanical behavior of both nano-CNT and nanostructured (CB) fillers. By plotting values of the composite initial modulus versus the filler–polymer interfacial area, points due to CB, CNT, and the hybrid CB-CNT system lie on the same curve.

APA, Harvard, Vancouver, ISO, and other styles

39

Chae, Gyu Sik, Duck Hyun Youn, and Jae Sung Lee. "Nanostructured Iron Sulfide/N, S Dual-Doped Carbon Nanotube-Graphene Composites as Efficient Electrocatalysts for Oxygen Reduction Reaction." Materials 14, no. 9 (April 23, 2021): 2146. http://dx.doi.org/10.3390/ma14092146.

Full text

Abstract:

Nanostructured FeS dispersed onto N, S dual-doped carbon nanotube–graphene composite support (FeS/N,S:CNT–GR) was prepared by a simple synthetic method. Annealing an ethanol slurry of Fe precursor, thiourea, carbon nanotube, and graphene oxide at 973 K under N2 atmosphere and subsequent acid treatment produced FeS nanoparticles distributed onto the N, S-doped carbon nanotube–graphene support. The synthesized FeS/N,S:CNT–GR catalyst exhibited significantly enhanced electrochemical performance in the oxygen reduction reaction (ORR) compared with bare FeS, FeS/N,S:GR, and FeS/N,S:CNT with a small half-wave potential (0.827 V) in an alkaline electrolyte. The improved ORR performance, comparable to that of commercial Pt/C, could be attributed to synergy between the small FeS nanoparticles with a high activity and the N, S-doped carbon nanotube–graphene composite support providing high electrical conductivity, large surface area, and additional active sites.

APA, Harvard, Vancouver, ISO, and other styles

40

Hung, Shang-Chao, Yi-Rong Chou, Cheng-Di Dong, Kuang-Chung Tsai, and Wein-Duo Yang. "Enhanced Activity of Hierarchical Nanostructural Birnessite-MnO2-Based Materials Deposited onto Nickel Foam for Efficient Supercapacitor Electrodes." Nanomaterials 10, no. 10 (September 27, 2020): 1933. http://dx.doi.org/10.3390/nano10101933.

Full text

Abstract:

Hierarchical porous birnessite-MnO2-based nanostructure composite materials were prepared on a nickel foam substrate by a successive ionic layer adsorption and reaction method (SILAR). Following composition with reduced graphene oxide (rGO) and multiwall carbon nanotubes (MWCNTs), the as-obtained MnO2, MnO2/rGO and MnO2/rGO-MWCNT materials exhibited pore size distributions of 2–8 nm, 5–15 nm and 2–75 nm, respectively. For the MnO2/rGO-MWCNT material in particular, the addition of MWCNT and rGO enhanced the superb distribution of micropores, mesopores and macropores and greatly improved the electrochemical performance. The as-obtained MnO2/rGO-MWCNT/NF electrode showed a specific capacitance that reached as high as 416 F·g−1 at 1 A·g−1 in 1 M Na2SO4 aqueous electrolyte and also an excellent rate capability and high cycling stability, with a capacitance retention of 85.6% after 10,000 cycles. Electrochemical impedance spectroscopy (EIS) analyses showed a low resistance charge transfer resistance for the as-prepared MnO2/rGO-MWCNT/NF nanostructures. Therefore, MnO2/rGO-MWCNT/NF composites were successfully synthesized and displayed enhanced electrochemical performance as potential electrode materials for supercapacitors.

APA, Harvard, Vancouver, ISO, and other styles

41

Gao, Shang Lin, Edith Mäder, and Rosemarie Plonka. "Surface Defects Repairing by Polymer Coating with Low Fraction of Nano-Reinforcements." Key Engineering Materials 334-335 (March 2007): 757–60. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.757.

Full text

Abstract:

Surface defects cause the measured tensile strength of glass and other brittle materials significantly lower than their theoretical values. Here, we describe an on-line process to ‘heal’ surface flaws and functionalise surface properties. A nanometer-scale hybrid coating layer based on styrene-butadiene copolymer with mutiwalled carbon nanotubes (MWCNTs) and/or nanoclays, as mechanical enhancement and environmental barrier layer, is applied to alkali-resistant glass fibres (ARG). The nanostructured and functionalised traditional glass fibres with low fraction of nanotubes or nanoclay (1 wt% in sizing) show significant improvement in both mechanical properties and environmental corrosion resistance. We introduce a healing efficiency factor and conclude that the coating modulus, thickness and roughness are responsible for the mechanical improvement of fibres. Furthermore, we show that the hybrid coating layer is essential for enhanced interfacial adhesion strength of the glass fibre reinforced cement composites.

APA, Harvard, Vancouver, ISO, and other styles

42

Deorsola, F. A., I. C. Atias Adrian, G. A. Ortigoza Villalba, and B. DeBenedetti. "Nanostructured TiC–TiB2 composites obtained by adding carbon nanotubes into the self-propagating high-temperature synthesis process." Materials Research Bulletin 46, no. 7 (July 2011): 995–99. http://dx.doi.org/10.1016/j.materresbull.2011.03.017.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Mohlala, M. Sarah, and Suprakas Sinha Ray. "Preparation and Characterization of Polymer/Multi-Walled Carbon Nanotube Nanocomposites." Solid State Phenomena 140 (October 2008): 97–102. http://dx.doi.org/10.4028/www.scientific.net/ssp.140.97.

Full text

Abstract:

This paper describes the preparation, characterization and properties of nanostructured composite materials based on poly(butylene adipate-co-polycaprolactam) (PBA-co-PCL)/multiwalled carbon nanotubes (MWCNTs) and polycaprolactone (PCL)/MWCNTs. The polymer/MWCNTs nanocomposites were prepared by mixing the polymers with various amounts of MWCNTs using both solution and melt blending processes. The dispersion of MWCNTs into the polymer matrix was analyzed by transmission electron microscopy (TEM) and the thermal stability of the nanocomposites was studied by thermal gravimetric analysis (TGA). Differential scanning calorimetry (DSC) was used to study the crystallization and melting behaviour of the polymer matrices containing the MWCNTs.

APA, Harvard, Vancouver, ISO, and other styles

44

Wang, Menglei, Kejing Yu, and Kun Qian. "In Situ Synthesis of Carbon Nanotubes/Graphene Nanoplatelets Hybrid Materials with Excellent Mechanical Performance." Nano 10, no. 04 (June 2015): 1550055. http://dx.doi.org/10.1142/s1793292015500551.

Full text

Abstract:

A two-step method for the preparation of hybrid materials consisting of multi-walled carbon nanotubes (MWCNTs) attached to graphene nanoplatelets (GNPs) was proposed. Firstly, poly (acryloyl chloride) was grafted in situ onto the surface of MWCNTs. Secondly, the obtained MWCNTs (MWCNTs-PACl) were reacted with acid-treated GNPs to form a nanotube–polymer–graphene hybrid. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA) were used to investigate the forming of the hybrid materials. FTIR results showed that MWCNTs/PACl and GNPs were successfully bridged by chemical bonds like O – C = O and C – O – C . Raman spectroscopy furthermore revealed that acryloyl chloride can be used to connect the MWCNTs and GNPs due to the defects of MWCNTs, and consequently the defects of the hybrid materials were limited. Meanwhile, TEM observation demonstrated the nanostructure clearly in which the MWCNTs with a polymer layer were attached successfully on the surface of GNPs. And TGA curves reflected that the content of MWCNTs and GNPs was about 46.5% in the hybrid materials. In addition, the tensile tests results showed that MWCNTs/GNPs hybrid materials can improve the mechanical performance of epoxy composites in higher degree, compared with MWCNTs or GNPs particles alone.

APA, Harvard, Vancouver, ISO, and other styles

45

Metaxa, Zoi S., Athanasia K. Tolkou, Stefania Efstathiou, Abbas Rahdar, Evangelos P. Favvas, Athanasios C. Mitropoulos, and George Z. Kyzas. "Nanomaterials in Cementitious Composites: An Update." Molecules 26, no. 5 (March 6, 2021): 1430. http://dx.doi.org/10.3390/molecules26051430.

Full text

Abstract:

This review is an update about the addition of nanomaterials in cementitious composites in order to improve their performance. The most common used nanomaterials for cementitious materials are carbon nanotubes, nanocellulose, nanographene, graphene oxide, nanosilica and nanoTiO2. All these nanomaterials can improve the physical, mechanical, thermal and electrical properties of cementitious composites, for example increase their compressive and tensile strength, accelerate hydration, decrease porosity and enhance fire resistance. Cement based materials have a very complex nanostructure consisting of hydration products, crystals, unhydrated cement particles and nanoporosity where traditional reinforcement, which is at the macro and micro scale, is not effective. Nanomaterials can reinforce the nanoscale, which wasn’t possible heretofore, enhancing the performance of the cementitious matrix.

APA, Harvard, Vancouver, ISO, and other styles

46

Li, Huifeng, Jian Wang, Yunhua Huang, Xiaoqin Yan, Junjie Qi, Jing Liu, and Yue Zhang. "Microwave absorption properties of carbon nanotubes and tetrapod-shaped ZnO nanostructures composites." Materials Science and Engineering: B 175, no. 1 (November 2010): 81–85. http://dx.doi.org/10.1016/j.mseb.2010.07.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Staudinger, Ulrike, Bhabani K. Satapathy, and Dieter Jehnichen. "Nanofiller Dispersion, Morphology, Mechanical Behavior, and Electrical Properties of Nanostructured Styrene-Butadiene-Based Triblock Copolymer/CNT Composites." Polymers 11, no. 11 (November 7, 2019): 1831. http://dx.doi.org/10.3390/polym11111831.

Full text

Abstract:

A nanostructured linear triblock copolymer based on styrene and butadiene with lamellar morphology is filled with multiwalled carbon nanotubes (MWCNTs) of up to 1 wt% by melt compounding. This study deals with the dispersability of the MWCNTs within the nanostructured matrix and its consequent impact on block copolymer (BCP) morphology, deformation behavior, and the electrical conductivity of composites. By adjusting the processing parameters during melt mixing, the dispersion of the MWCNTs within the BCP matrix are optimized. In this study, the morphology and glass transition temperatures (Tg) of the hard and soft phase are not significantly influenced by the incorporation of MWCNTs. However, processing-induced orientation effects of the BCP structure are reduced by the addition of MWCNT accompanied by a decrease in lamella size. The stress-strain behavior of the triblock copolymer/MWCNT composites indicate higher Young’s modulus and pronounced yield point while retaining high ductility (strain at break ~ 400%). At a MWCNT content of 1 wt%, the nanocomposites are electrically conductive, exhibiting a volume resistivity below 3 × 103 Ω·cm. Accordingly, the study offers approaches for the development of mechanically flexible functional materials while maintaining a remarkable structural property profile.

APA, Harvard, Vancouver, ISO, and other styles

48

Alexiou, Vasiliki F., George N. Mathioudakis, Konstantinos S. Andrikopoulos, Amaia Soto Beobide, and George A. Voyiatzis. "Poly(ethylene Terephthalate) Carbon-Based Nanocomposites: A Crystallization and Molecular Orientation Study." Polymers 12, no. 11 (November 8, 2020): 2626. http://dx.doi.org/10.3390/polym12112626.

Full text

Abstract:

Hybrid polymeric materials incorporating carbon nanostructures or inorganic constituents stand as a promising class of materials exhibiting distinct but also complementary features. Carbon nanotubes have been proposed as unique candidates for polymer reinforcement; however, sustained efforts are further needed in order to make full use of their potential. The final properties of the reinforced polymer are controlled in part by the morphology and the eventual molecular orientation of the polymer matrix. In the present study, multiwall carbon nanotubes (MWCNTs) were utilized in order to reinforce polyethylene terephthalate (PET) composites. The effect of CNTs on the crystallization and the orientation of the structurally hybridized polymeric material has been investigated from the perspective of assessing their impact on the final properties of a relevant nanocomposite product. Functionalized MWCNTs were used to achieve their optimal dispersion in the polymer matrix. The physical properties of the composites (i.e., crystallinity and orientation) were characterized via differential scanning calorimetry, X-ray diffraction, and polarized Raman microscopy. The addition of well-dispersed CNTs acted as a nucleation agent, increasing the crystallization of the polyethylene terephthalate matrix and differentiating the orientation of both CNTs and macromolecular chains.

APA, Harvard, Vancouver, ISO, and other styles

49

He, Zhongming, Chen Wang, and Chuansheng Chen. "Microwave-Assisted Synthesis and Catalytic Performance of Carbon Nanotubes/Flower-Patterned Zinc Oxide Nanostructures." Journal of Nanoscience and Nanotechnology 20, no. 8 (August 1, 2020): 4971–76. http://dx.doi.org/10.1166/jnn.2020.18485.

Full text

Abstract:

It is essential for multifunctional asphalt to develop the new nanostructures with high photocatalytic activity in order to endow asphalt with the self-cleaning ability of contamination. Multi-walled carbon nanotubes/ZnO (MWNTs/ZnO) composites were synthesized based on microwave irradiation and their structure and photocatalytic properties were investigated. The experimental results showed that MWNTs/ZnO powder with different morphologies was attained such as cone-shaped, floral-patterned and fusiform structures. The as-obtained MWNTs/ZnO composites were proved to possess quite high catalytic activities for degradation of methyl orange (MO). Especially, the floral-patternedMWNTs/ZnO composites displayed better photocatalytic performance than the other composites indicating that the resultant MWNTs/ZnO composites can be used as photocatalysts without any additional treatment.

APA, Harvard, Vancouver, ISO, and other styles

50

Shchegolkov, A. V., A. V. Shchegolkov, I. D. Parafimovich, E. A. Burakova, A. V. Kobelev, and T. P. Dyachkova. "Aspects of the directional synthesis of carbon nanotubes to create hierarchical radio-absorbing composite materials." Proceedings of the Voronezh State University of Engineering Technologies 80, no. 4 (March 21, 2019): 337–43. http://dx.doi.org/10.20914/2310-1202-2018-4-337-343.

Full text

Abstract:

The conducted information review showed that there are various types of radio absorbing materials. The expansion of the working wavelength range for radio-absorbing composites is possible due to the combined use of conductive fillers, characterized by different magnetic and dielectric characteristics and the value of electrical conductivity. As a rule, the increase in the efficiency of radio absorption of materials is associated with an increase in the concentration of metal fillers in them, as a result of which the weight and size parameters increase proportionally. To avoid this, the use of carbon nanomaterials, which have the ability to create self-organizing hierarchical structures in the bulk of the composite, allows. Varying the composition of the catalytic systems of the CVD process allows directional synthesis of carbon nanomaterials with the necessary morphological characteristics. To assess the effect of the composition of the catalyst on the morphology and structure of the synthesized CNTs, 3 Ni / MgO catalyst compositions with different contents of the active component (Ni) were selected. The effectiveness of the obtained catalysts was determined by the specific yield of CNTs (gC/gkat). The morphology and structure of the catalysts and the synthesized CNTs were studied by means of scanning electron microscopy (a Hitachi H-800 transmission electron microscope). CNTs were additionally examined by transmission electron microscopy (a Hitachi H-800 transmission electron microscope). The use of a nickel-based catalyst provides the material with magnetic properties. The diameter of carbon filiform formations synthesized on Ni/0.16MgO and Ni / 0.3MgO catalysts is ~ 30 ? 60 nm. The Ni/0.5MgO system is characterized by low productivity in one-dimensional nanostructures; the sample after the CVD process contains a large number of unstructured forms of carbon and an unchanged catalyst. Structural diversity in carbon nanomaterials allows to obtain on their basis an effective hierarchical structure in the radio absorbing composite..

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Nanotubes. Nanostructured materials. Carbon composites'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles