In Tech-Functionalization of carbon nanotubes (original) (raw)
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Mechanical Behavior and surface modification of CNTs that are functionalized with Polymer Composites
International Journal for Research in Applied Science and Engineering Technology IJRASET, 2020
In the present investigation, the aim was to improve the modification of the surface of the CNTs with different chemical solutions and the characteristics of the F-CNTs reinforced with polymeric composites, so as to promote uniform dispersion and improve the bond between CNTs and polymers. To this end, the CNTs were initially treated with various methods such as acid treatment, silane treatment, thiolation treatment and amine treatment. The functionalization CNTs were characterized by the Fourier transform infrared (FTIR). The main objective of this work was to improve the mechanical characteristics of a polymer composite using nano-reinforcements. The superior properties of nanotubes (CNT) make polymeric compounds a potentially reinforced agent. The interfacial adhesion between the CNTs and the uniform dispersion of the CNTs and the polymer are critical factors that need to be improved to improve the mechanical properties of the polymer compounds. The effect of F-CNT with the polymer content in the composite on the flexural strength, flexural modulus, tensile modulus, tensile strength and fatigue life is assessed. Keywords: Functionalized-CNT's, FTIR, tensile, fatigue and flexural. I. INTRODUCTION Since Iijima's "Breakthrough and Milestone" article of the year (1991) [1], the focal point of carbon nanotubes (CNT) has been an in-depth investigation thanks to their fantastic mechanical, electromagnetic and composite performance. CNT applications have recently been recorded, for example, in Nano devices, field emanation shows, hydrogen storage, moment support, filter test microscopy tests and Nano devices, nano / biosensors, etc. Interesting nuclear structure, high viewing ratio and remarkable mechanical characteristics (quality and adaptability) make CNT perfect fortifying fillers, for example in the year (2007) Shen.J [2] observed the double increase in quality of flexion including 1% by weight of MWCNT without amine Critical impact on the flexural modulus. Comparative results were performed by Chen [3] for epoxy resin nanotubes in epoxy compounds. Furthermore, Zhang [4] demonstrated that a low content of MWCNT improved its dispersion on an epoxy grid and mechanical properties, but a higher MWCNT substance could cause the disintegration of mechanical properties. CNT compounds also show significant improvements in electrical conductivity. The electrical and mechanical properties of CNT polymer compounds appear to be influenced by different nanotube cleaning states or potential adaptation. Tamburri [5] saw that the conductivity of poly-1, 8-diaminonphthalene was charged with SWCNT increments by extending the CNT element due to the proximity of the-OH and-COOH groups presented by the mixed treatment in the untreated application. < HNO 3 < KOH < HNO 3 / H 2 SO 4. Kim and colleagues [6] observed that the "conductivity" of the epoxy / MWCNT compounds decreases with the increase of the oxidation time and the temperature of MWCNT in HNO3. John Kathi et al [7] organized rubber resin nano composites and distinctive weight percentages of unmodified, silanized and oxidized multiple-walled carbon nanotubes (MWCNT) according to the mold formation strategy. Analyze the bending properties of the MWCNT content with impact. The results assumed that the expanded and improved flexible modules stack and MWCNT resistance were observed. The mechanical performance characteristics decreased when the MWCNT content exceeded 0.2% by weight due to the assembly of MWCNT. Therefore, the results demonstrate the impact of functionalization on the bond between the bonded edge between the resin and the MWCNT. In this work, it controls the adequate dispersion of CNT in the polymer through functionalization, silanization, treatment with amines, etc. It was learned that by modeling the adhesions between CNT and the polymer due to the low compaction between them. To destroy these bonds between CNTs and the polymer, it was necessary to simulate the bonds of the substance in the walls of the CNTs to obtain a strong bond with the polymer. Modern advances in the field of nanotechnology require the improvement of nano composites to improve mechanical properties. Further improvement of CNT dispersion in polymers through functionalization and silanization prior to dispersion in the polymer.
Review Article: Hybrid Materials Based on Carbon Nanotubes
Vietnam Journal of Science and Technology
Carbon nanotubes-based hybrid and composite materials, recently, are a hot topic in research about advanced materials. Nanotubes are functionalized and hybridized with both organic and inorganic compounds for designed applications. Hybrid materials can be fabricated by direct or in-direct method. Some investigations about electrical, optical and photocatalytic properties of hybrid materials would be discussed.
AIPConfProc591(2001)483 - Large Scale Synthesis of CNTs and their Composite materials.pdf
MgO supported transition metals are very interesting systems for possible large scale synthesis of carbon nanotubes. Indeed, the catalytic decomposition of acetylene at high temperature leads to the formation of very thin multi-wall carbon nanotubes (inner and outer diameters are in the range of 2-4 nm and 5-9 nm, respectively). The decomposition of methane, on the other hand, produces bundles and isolated single-wall nanotubes (SWNTs) of high purity. Typically, the diameters of isolated SWNTs are 1-5 nm. For the SWNTs aligned in the bundles, the diameter values vary between 0.8 and 2 nm. The samples are characterised by TEM, and HREM. The purity of the nanotubes is evaluated by PIXE (proton induced X-ray emission) and by thermal analysis. The nanotubes are cut mechanically in a ball-mill and the introduction of various functional groups is determined by XPS. Finally, homogeneous mixture of carbon nanotubes and polyacrylonitrile will be shown.
AIPConfProc633(2002)82 - Mechano-chemical functionalization of CNTs.pdf
Short, functionalized multiwall carbon nanotubes were prepared by a simple mechano-chemical way. The fundamental idea of our method is breaking of the nanotubes under reactive gas atmosphere such as CO, COC1 2 , C1 2 , NH 3 , CH 3 SH in a ball mill. During this ball milling procedure the tube length decreased to 200-300 nm, while the specific surface area increased by about 20% and the inner pore of the nanotubes became accessible.
Meta- and hybrid-CNTs: A clue for the future development of carbon nanotubes
Materials Science and Engineering: C, 2007
A new generation of carbon nanotubes (CNTs), which may be named "meta-nanotubes", is more and more the focus of the research worldwide. They result from the transformation of "regular" CNTs by various ways such as functionalisation, doping, substitution, etc. The new nanomaterials thereby created are likely to exhibit new behaviors, specifically regarding properties that pristine CNTs do not possess (reactivity, solubility, magnetism…). The paper includes the description of the various routes to synthesize hybrid CNTs and their related advantages and limitations, while providing examples of the resulting materials from both literature and author's team work. Hybrid SWNTs (abbreviated as X@SWNTs) are one example of meta-nanotubes, and consist in SWNTs whose the hollow core is fully or partially filled with foreign atoms, molecules, or compounds. The inserted material may then exhibit a peculiar behavior with respect to the macroscopic state, for several non-exclusive reasons: 1D-dimension preventing electron scattering and enhancing the role of surface atoms, protection from surface adsorption of disturbing molecules by the carbon sheath, anisotropic lattice distortion or creation of new structures due to imposed dimensions, interactions/electron coupling with the surrounding carbon lattice. A wide field is thus open, possibly even wider than for pristine SWNTs.
Carbon Nanotubes and Semiconducting Polymer Nanocomposites
intechopen.com
474 4.2 Mechanically reinforced composite With respect to mechanically effective reinforcement, basically required features for composite components are purity, aspect ratio, dispersion, alignment and interfacial stress transfer. Among these, the interfacial stress transfer, characterized by the applied shear stress at which the interface fails, is the most important. However, CNTs have atomically smooth non-reactive surfaces, and then lack of interfacial bonding between the CNTs and polymer. In order to increase bonding sites to the polymer chain, chemical modification and functionalization of CNTs such as solution processing, melt processing, and chemical processing were proposed. Quantum mechanics and molecular dynamics calculations supported this approach [35-38]. By chemical functionalizing and integrating CNTs into epoxy polymer, Margrave et al [39] found that the composite with 1wt% functionalized CNTs showed an increase of 18% and 24% in tensile strength and modulus respectively over the epoxy composites with unfunctionalized CNTs and a 30% increase in tensile modulus over pure epoxy resin. The enhancement was due to the strong interaction between epoxide rings on the epoxy resin and the functionized groups on CNT walls which were confirmed by infra-red and Raman spectroscopy. A composite formed by in-situ polymerization from the polycondensation of diamine and diacid monomers comprising with dispersed CNTs aligned with rigid-rod polymers [40] showed that the tensile modulus, tensile strength and elongation to break of composite having 10 wt% CNT increased by 20, 60 and 40% respectively. In this composite there was no claim of covalent bond formation at the interfaces of components. The alignment of CNTs could be the reason of the enhancement. By combining the uniformly dispersed nanotube with polypropylene matrix/solvent mixture and then heating the nanotube/matrix mixture to a temperature above the melting point of the matrix materials, Shambaugh et al. [41] recently disclosed a method for producing SWNT-polypropylene composite. The fiber made from composite with 1 wt% of CNTs showed more than 50% increase in tensile strength compared to fiber drawn from matrix materials alone. This substantial increase in strength was believed to be due to a uniform dispersion of CNTs in the matrix materials. In addition, mechanical reinforcements of polymer/CNTs composites have found to be significantly enhanced when high purity nanotubes were exfoliated and well dispersed in the polymer matrix. The above results show that not only the interfacial bonding but also the type of polymer and the conditions used in making the composite are important factors to produce a strong composite. On the other hand, in some composites, CNTs act as a nucleating agent for polymer crystallization [9, 42-44] and reorientation. For example, SWNTs induced oriented crystallization is observed in PET/SWNTs composites [42]. Two samples, PET and PET/ SWNTs (1wt% loading) are prepared under identical conditions by melt compounding at 270 o C. Both PET and PET/SWNTs samples were made into 0.5 mm thick, 0.4 mm wide strips and subsequently stretched to a draw ratio of four to induce PET and SWNTs o r i e n t a t i o n. A s c a n b e s e e n f r o m F i g. 3 , w i d e-a n g l e X-r a y d i f f r a c t i o n (W A X D) o f b o t h materials shows that PET is oriented in the samples (Fig. 3A and Fig. 3C). However, when the train PET and PET/SWNTs were heated and were recrystallized by cooling down, only PET/SWNTs shows the orientation but not the neat PET (Fig. 3B and Fig. 3D). Individual CNTs also have found to promote polypropylene (PP) crystallization, as a result, thick PP interfacial layer is formed on the nanotube surface [43]. Polypropylene transcrystals were observed on the carbon nanotube surface (Figure 2E), when polymer melt was isothermally crystallized in the temperature range of 118 to 132 °C. In PP/CNTs fiber samples melted and
Emerging Materials Research, 2013
Carbon nanotubes (CNT) are nature’s finest gift to mankind, the most amazing and wonderful nanostructure that the human being has discovered so far. CNT are either single walled or multiwalled and have been studied extensively. A large number of research articles, review articles and books have been published on this topic. However, review articles covering all the aspects of CNT are rarely found. This article gives an overview of CNT in terms of classification, synthesis, characterization, functionalization, properties, composites, applications and future directions.
Handbook of Carbon Nanotubes-Polymer Nanocomposites
Structural materials are the basic necessity of this advanced society. Thus, to develop new fundamental materials with higher strength and better resistance to heat changes, one should have basic knowledge about the nanocomposite and their constituents. This book provide basic insight into the general knowledge of nanomaterials with special emphasis towards carbon nanotubes (CNTs), their functionalization and there use in various fabrication of nanocomposites. The development of nanocomposites using nanotube fillers has evolved very quickly owing to unique features (tensile strength, electrical and thermal conductivity) of CNTs hence it is highly important to understand the driving forces (concentrations, functional groups, chirality, temperature etc) behind homogenous dispersion in the various matrices. Keeping in mind these motivations, we have compiled this book that will provide young researchers with basic knowledge about synthesis of carbon nanotubes and how the several parame...