Fabrication Of Carbon Nanotubes Research Articles

Crystallization- and morphology-tunable Fe3O4@C core–shell composites decorated on carbon nanotube skeleton with tailorable electromagnetic wave absorption behavior

Herein, a scalable method is developed to fabricate carbon nanotube (CNT)/Fe3O4@C composites, in which the crystallization and morphology of the carbon shell on the surface of Fe3O4 nanoparticles can be controlled by manipulating the synthesis conditions of chemical vapor deposition technology. Owing to the synergic dissipation effect of the core–shell structure, as well as the excellent conductive loss induced by the CNT skeleton, the CNT/Fe3O4@C composite shows a minimum reflection loss of −50.1 dB at 9.7 GHz and an effective bandwidth of 4.6 GHz. This study provides new insight into preparing core–shell-structured microwave absorbers with excellent performance.

Dispersion and Damage of Carbon Nanotubes in Carbon Nanotube/7055Al Composites During High-Energy Ball Milling Process

High-energy ball milling (HEBM) combined with powder metallurgy route was used to fabricate carbon nanotube (CNT) reinforced 7055Al composites. Two powder morphology evolution processes (HEBM-1 and HEBM-2) were designed to investigate the dispersion and damage of CNTs during HEBM process. HEBM-1 evolution process involved powder flattening, cold-welding and fracture, while HEBM-2 evolution process consisted of powder flattening and fracture. For HEBM-1, the repetitive fracture and cold-welding process was effective for dispersing CNTs. However, the powder flattening process in HEBM-2 was unsuccessful in dispersing CNTs due to two reasons: (1) the thickness of flaky Al powders exceeded the critical value, and (2) the clustered CNTs embedded in flaky Al powders could not be unravelled. Because of the broadening of D band and the appearance of a new defect-related D’ band, product of ID/IG and full width half maximum of D band, rather than ID/IG, was used to evaluate the actual damage of CNTs. It indicates that the damage of CNTs was severe in powder flattening and fracture stages, while the damage of CNTs was small in powder cold-welding stage.

Effect of Electrochemical Oxidation on Physicochemical Properties of Fe‐Containing Single‐Walled Carbon Nanotubes

AbstractMetal catalysts are necessary for fabricating carbon nanotubes, but are often considered impurities in the end products, and arduous steps are used to remove catalyst residues from the nanotube structure. However, as metals can be electrocatalytic, instead of removing them we can utilize their role in detection of analgesics. Herein, we study the physicochemical properties of Fe‐containing single‐walled carbon nanotubes (SWCNTs), and the effect of simple oxidative pretreatment on them. We show that a gentle anodic pretreatment i) increased the amount of oxidized Fe nanoparticles, most likely exhibiting phases Fe3O4 and Fe2O3 and ii) effectively removed disordered carbonaceous material from SWCNT bundles surfaces. Pretreatment had only a marginal effect on sensitivity towards analgesics. However, interestingly, selectivity of Fe‐SWCNTs towards paracetamol and morphine could be modified with pretreatment. Through this kind of in‐depth investigation, we can, to a certain extent, correlate various material properties of SWCNTs with the observed electrochemical performance. This approach allows us to evaluate what factors in SWCNTs truly affect the electrochemical detection of biomolecules.

Wet-spinning fabrication of multi-walled carbon nanotubes reinforced poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) hybrid fibers for high-performance fiber-shaped supercapacitor

Fiber-shaped supercapacitors with high energy density and power density are promising as energy storage device for flexible electronics because of their one-dimensional distinct structure, excellent flexibility and potential to be integrated. In this study, multi-walled carbon nanotubes (MWCNT)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) hybrid fibers with different fraction of MWCNT were fabricated via wet-spinning and post-treatment process. Due to the synergistic effects of two components, the designed hybrid fibers displayed excellent conductivity and mechanical property. Furthermore, the symmetric flexible supercapacitor based on our prepared hybrid fibers possessed an impressive specific capacitance (117.0 mF/cm2 at current density 0.1 mA/cm2), superior energy/power characteristics (16.3 μWh/cm2 at power density of 0.05 mW/cm2), as well as satisfactory cycle stability (90% capacitance retention after 2000 charge/discharge cycles) and flexibility (87% capacitance retention after 1000 bending cycles). Thus, MWCNT/PEDOT:PSS hybrid fibers are a promising candidate for constructing flexible electrochemical energy storage device.

Growth of nitrogen-doped carbon nanotubes using Ni/La2Zr2O7 as catalyst: Electrochemical and magnetic studies

The combination of different nanomaterials to achieve particular applications is a topic with an increasing impact on diverse areas of nanotechnology. In particular, the material of La2Zr2O7 (LZO) and NiO could be employed as a source of catalyst for carbon nanotube fabrication. In this work, the Ni/LZO material was utilized to fabricate nitrogen-doped multiwalled carbon nanotube (N-MWCNTs). The N-MWCNTs were produced at 850 °C by the aerosol assisted catalytic chemical vapor deposition method using benzylamine as the sole carbon and nitrogen precursor. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and vibrating sample magnetometry. Before the synthesis of N-MWCNTs, NiO was reduced to Ni to act as a catalyst and LZO as support. N-MWCNTs exhibited the typical feature bamboo shape morphology with small nanoparticles anchored inside and on its surface. The electrochemical studies show interesting results about charge capacity and a hydroquinone/quinone redox process of oxygen functionalities. The magnetic properties of N-MWCNTs showed a ferromagnetic behavior with a saturated magnetization of 43 emu/g at 0.2 T.

Fabrication and characterization of functionalized multi-walled carbon nanotube mixed-matrix membrane for treating biochemical and chemical oxygen demands of surface waters

In this work, a mixed-matrix (MM) membrane consisting of functionalized multi-walled carbon nanotube (MWCNT), polyethersulfone (PES) and polyester non-woven fabric was fabricated using immersion precipitation. The membrane capability in reducing the biochemical oxygen demand (BOD) and chemical oxygen demand (COD) levels of the surface water samples collected from rural areas in Sarawak, Malaysia are tested. MWCNTs were functionalized using chemical oxidation to promote functional group onto their sidewalls. Raman analysis reveals a higher peak in D-band than G-band in the functionalized CNT but the higher ID/IG intensity ratio was demonstrated by CNT treated with strong acid. Surface morphological characterization verified the existence of the defects in CNT structures, which was reflected on the sidewall defects, debundling and shortening of the MWCNTs. Meanwhile, the surface waters were tested for BOD and COD levels and treated with three different types of membrane by conventional vacuum filtration. Membrane of raw MM displayed the best treatment capability which is reflected on its ability to maintain the BOD level and reduce the COD level with a consistent percentage. Thus, this work provides a different insight in membrane capability in treating BOD and COD levels in surface waters.

General Fabrication of 3D Hierarchically Structured Bamboo-like Nitrogen-Doped Carbon Nanotube Arrays on 1D Nitrogen-Doped Carbon Skeletons for Highly Efficient Electromagnetic Wave Energy Attenuation.

Hierarchically three-dimensional (3D) micro-nanostructures have promising applications in multifarious fields. Herein, we report a general strategy, that is, in situ catalysis process, for fabrication of nitrogen-doped carbon nanotube (NCNT) arrays on one-dimensional (1D) nitrogen-doped carbon (NC) skeletons. The NCNT arrays branch out from the 1D NC surfaces, resulting in the formation of hierarchically 3D micro-nanostructures. The strategy is involved in the pyrolysis of M-precursor (M = Fe, Co, and Ni) nanowires with the assistance of dicyandiamide. During the synthesis process, the metal components in the precursors serve as catalysts for growing NCNTs, while dicyandiamide provides carbon and nitrogen sources. With the ongoing reaction, the NCNTs were catalytically grown and branched out from 1D NC skeletons. Through the strategy, three kinds of hierarchically 3D structures with encapsulated Fe/Fe3C, Co, and Ni nanoparticles, respectively, were fabricated successfully. As functional materials for attenuating electromagnetic wave energy, these hierarchically 3D structures exhibit satisfactory performances even at a low matching thickness, exceeding most of the carbon-based materials. Typically, the minimal reflection losses of the 3D structures can reach -10.0 dB even as the matching thickness is in the range of 1.4-2.0 mm. Experimental results demonstrate that the excellent attenuation properties toward electromagnetic wave energy are relative to high conduction loss at a low frequency and high dielectric relaxations at a high frequency as well as better impedance matching with the input impedance of the free space. Our method presented here opens a general way for the development of hierarchically 3D carbon-based micro-nanostructures for their practical applications.

Frequency dependence of dielectrophoretic fabrication of single-walled carbon nanotube field-effect transistors

A new theoretical model for the dielectrophoretic (DEP) fabrication of single-walled carbon nanotubes (SWCNTs) is presented. A different frequency interval for the alignment of wide-energy-gap semiconductor SWCNTs is obtained, exhibiting a considerable difference from the prevalent model. Two specific models are study, namely the spherical model and the ellipsoid model, to estimate the frequency interval. Then, the DEP process is performed and the obtained frequencies (from the spherical and ellipsoid models) are used to align the SWCNTs. These empirical results confirm the theoretical predictions, representing a crucial step towards the realization of carbon nanotube field-effect transistors (CNT-FETs) via the DEP process based on the ellipsoid model.

On-Surface Hydrogenation of Buckybowls: From Curved Aromatic Molecules to Planar Non-Kekulé Aromatic Hydrocarbons.

Functionalization of surfaces with derivatives of Buckminsterfullerene fragment molecules seems to be a promising approach toward bottom-up fabrication of carbon nanotube modified electrode surfaces. The modification of a Cu(100) surface with molecules of the buckybowl pentaindenocorannulene has been studied by means of scanning tunneling microscopy, carbon monoxide-modified noncontact atomic force microscopy, time-of-flight secondary mass spectrometry, and quantum chemical calculations. Two different adsorbate modes are identified, in which the majority is oriented such that the bowl cavity points away from the surface and the convex side is partially immersed into a four-atom vacancy in the Cu(100) surface. A minority is oriented such that the convex side points away from the surface with the five benzo tabs oriented basically parallel to the surface. Thermal annealing leads to hydrogenation and planarization of the molecules in two steps under specific C-C bond cleavage. The benzo tabs of the convex side up species serve as a hydrogen source. The final product has an open-shell electron structure that is quenched on the surface.

Flexible All-Solid-State Li-Ion Battery Manufacturable in Ambient Atmosphere.

The rational design and exploration of safe, robust, and inexpensive energy storage systems with high flexibility are greatly desired for integrated wearable electronic devices. Herein, a flexible all-solid-state battery possessing competitive electrochemical performance and mechanical stability has been realized by easy manufacture processes using carbon nanotube enhanced phosphate electrodes of LiTi2(PO4)3 and Li3V2(PO4)3 and a highly conductive solid polymer electrolyte made of polyphosphazene/PVDF-HFP/LiBOB [PVDF-HFP, poly(vinylidene fluoride-co-hexafluoropropylene)]. The components were chosen based on their low toxicity, systematic manufacturability, and (electro-)chemical matching in order to ensure ambient atmosphere battery assembly and to reach high flexibility, good safety, effective interfacial contacts, and high chemical and mechanical stability for the battery while in operation. The high energy density of the electrodes was enabled by a novel design of the self-standing anode and cathode in a way that a large amount of active particles are embedded in the carbon nanotube (CNT) bunches and on the surface of CNT fabric, without binder additive, additional carbon, or a large metallic current collector. The electrodes showed outstanding performance individually in half-cells with liquid and polymer electrolyte, respectively. The prepared flexible all-solid-state battery exhibited good rate capability, and more than half of its theoretical capacity can be delivered even at 1C at 30 °C. Moreover, the capacity retentions are higher than 75% after 200 cycles at different current rates, and the battery showed smaller capacity fading after cycling at 50 °C. Furthermore, the promising practical possibilities of the battery concept and fabrication method were demonstrated by a prototype laminated flexible cell.

Synthesis and plasma surface functionalization of carbon nanotubes for using in advanced epoxy-based nanocomposites

In this study, thermal chemical vapor deposition (CVD) method was utilized to fabricate carbon nanotubes (CNTs) using an Fe/Al catalyst. Plasma enhanced CVD (PECVD) was applied to coat CNTs surfaces with a hydrophobic poly(hexafluorobutyl acrylate) (PHFBA) thin film. Then pure CNT and surface-modified CNT (f-CNT) were used as nanofillers at 0.5–3 wt% in bisphenol-A (DGEBA) and phenolic novolac types epoxy (EPN) resins to produce composite materials with superior properties. For characterization of both types of CNTs, FTIR, XRD, SEM, TEM and TGA analyses were performed. The morphologies of composites were examined via XRD and SEM. Thermal properties of composites were revealed by TGA. The influences of CNT surface functionalization and matrix type on the thermal, mechanical, electrical conductivity and surface wettability properties of composites were investigated. EPN based composites exhibited higher mechanical properties than that DGEBA based ones. At 1.5 wt% f-CNTs, the Young's modulus and tensile strength of the nanocomposites were found 6.9 ± 0.50 GPa and 141.0 ± 7.8 MPa, respectively using DGEBA matrix; 8.7 ± 0.59 GPa and 153.4 ± 7.9 MPa respectively, using EPN matrix. Composites electrical conductivity increased with increasing both type CNTs amount and reached a maximum value of 10−4 S/m and 10−6 S/m at 3 wt% of neat and f-CNTs contents.

A novel fluorometric aptasensor based on carbon nanocomposite for sensitive detection of Escherichia coli O157:H7 in milk

Escherichia coli O157:H7 is an extremely serious foodborne pathogen accounting for a vast number of hospitalizations. In this system, a simple, rapid, and safe compound method was developed based on carbonyl iron powder (CIP) and multiwalled carbon nanotubes (MWCNT). Then, the CIP@MWCNT-based aptasensor was constructed by strong π-stacking between nanocomposite and aptamer, single-strand DNA, causing fluorescent quenching of the dye-labeled aptamer. The restoration of dye fluorescence could be achieved when aptamer came off the surface of the CIP@MWCNT nanocomposite due to the presence of target bacteria. To the best of our knowledge, this fabrication of magnetic carbon nanotubes without irritating and corrosive reagents is described for the first time. The sensing platform was also an improvement on the conventional formation of the aptasensor between carbon materials and DNA aptamer. The nanocomposite was verified by diverse characterization of zeta potential, Fourier-transform infrared spectroscopy, transmission electron microscopy, and energy dispersive x-ray analysis. The CIP@MWCNT-based aptasensor was an effective nanoplatform for quantitative detection of E. coli O157:H7, and was measured to have high specificity, good reproducibility, and strong stability. The aptasensor's capacity to quantify E. coli O157:H7 was as low as 7.15 × 103 cfu/mL in pure culture. The detection limit of E. coli O157:H7 was 3.15 × 102 cfu/mL in contaminated milk after 1 h of pre-incubation. Hence, the developed assay is a new possibility for effective synthesis of nanocomposites and sensitive tests of foodborne pathogens in the dairy industry.

Carbon Nanotube Metal Polymer Composites for Flexible Active Interconnects

We report on the fabrication and characterization of metal polymer carbon nanotube (MPCNT) composites for flexible active interconnects. Our experiments demonstrated that such carbon nanotube (CNT)-reinforced polymer-metal composites have several times higher tolerance to bending strains than the metal-polymer composites without the CNTs layer. Since CNT-polymer layer is electrically insulated from the metal layer until destructive breakdown, it is feasible to fabricate electronic components isolated from the metal layer in the MPCNT composites. Thus, the MPCNT composites-based interconnects could be utilized as a platform for CNTs-based sensors and CNT Thin Film Transistors (TFTs). To estimate the electrical characteristics of the MPCNT devices, we developed the compact unified charge control model (UCCM) for CNT TFTs. The model was validated by comparison of the simulated results with experimental data reported earlier. We further investigated humidity sensing based on the CNT-Poly(N-isopropylacrylamide) (PNIPAm) composites, and demonstrated the potential for the MPCNT sensing applications.

Laser-Based Fabrication of Carbon Nanotube–Metal Composites on a Polymer Substrate: Experimental Study and Characterizations

Abstract Flexible electronic devices have several advantages and multiple current or potential applications. However, the reliability and durability of their metal components (which often exist) may suffer from large and repeated strains during many applications. Carbon nanotube (CNT)-metal composite films that were laser-sintered on flexible substrates were shown to be very promising in addressing the reliability and durability issues. However, to the authors’ best knowledge, CNT–metal interfaces in a laser-sintered CNT–metal composite film on a polymer substrate and the composite–polymer interface have not been sufficiently characterized and understood. In this paper, CNT–silver composite films were produced on polyimide substrates by laser sintering, and the fabricated samples were characterized through scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Under the conditions studied, it has been found that: (1) for the CNT–silver interfaces in the composite, a significant amount of Ag–C chemical bonds is unlikely to exist, and (2) for the composite–polyimide interface, mechanical interlocking is expected to play an important role in the interfacial adhesion, while a significant diffusion of silver into the polyimide substrate is not observed. Besides, chemical reactions have likely occurred around the interface, causing the formation of Ag2O due to the reaction between silver from the composite and oxygen (in a certain form) from the polyimide substrate.

A unified electrical model based on experimental data to describe electrical transport in carbon nanotube-based materials

Understanding the electrical transport in carbon nanotube (CNT) materials is one key to reach very high electrical conductivities. All CNT material resistivity (?? (T)) as function of the temperature are fully apprehended by their reduced activation $$W(T) = \frac{{d\ln (\rho )}}{{d\ln (T)}}$$ curves. Up to now, no model accurately fits W(T) curves, thus preventing from precisely describing the CNT material electrical transport. We present a new electrical transport model that perfectly fits all W(T) curves found in the literature and in our own data. CNT material resistivities are modeled by ??(T)= ??0(T????? + M(1 + ??T??T2)). Our model has few enough parameters (??, M, ??, ??) to relate them to the CNT physics. Below 70 K, we experimentally show that CNT material resistivity follows the Luttinger Liquid theory justifying the T????? term in our model. Above 70 K, the polynomial part becomes dominant and depends on the two different CNT fabrication techniques which lead to two very different yarn structures. For yarns made from floating catalyst chemical vapor deposition CNTs, the polynomial is explained by the percolation of metallic CNT walls. Whereas, the polynomial of yarns spun from CNT arrays is explained by the electrical transport in CNT bundles which are the basic building blocks of this type of yarns.

A high gauge-factor wearable strain sensor array via 3D printed mold fabrication and size optimization of silver-coated carbon nanotubes

The development of 3D print technology provided an opportunity to achieve fast and accurate fabrication of wearable sensor arrays. In this paper, high-sensitivity flexible and stretchable silver-coated carbon nanotube (Ag@CNT) wearable strain sensor arrays are fabricated using 3D printing technology and composite nanomaterial synthesis. Ag@CNTs with uniform and compact particles were synthesized with different sizes of carbon nanotubes (CNTs) using a reduction method. Strain sensor arrays were fabricated accurately and efficiently with the aid of 3D printed molds. Sensors with different Ag@CNTs were then compared comprehensively, and it was found that the Ag@CNT (short) sensor, which had a gauge factor (GF) of 62.8 in the 0% to 14.44% stretch range and a GF of 831.3 in the 14.44% to 21.11% stretch range, can significantly enhance the detection of small movements. These wearable strain sensor arrays were utilized in the application of traditional Chinese medicine pulse diagnosis and gesture recognition.

Carbon nanotubes, orange dye, and graphene powder based multifunctional temperature, pressure, and displacement sensors

This work presents design, fabrication, and investigation of carbon nanotube (CNT), orange dye (OD), and graphene powder based multifunctional sensors. The output of the multifunctional sensors is observed as change in resistance and impedance values for an input change in temperature, pressure, and compressive displacement between the sensors electrodes. Using these sensors, temperature variation ranging from 30 to $$65^{\circ }\hbox {C}$$ , pressure 0 to 0.1 $$\hbox {kgf\,cm}^{-2}$$ and longitudinal compressive displacements of 0 to 110 $$\upmu \hbox {m}$$ are measured as change in resistance and impedance at two fixed frequencies, i.e., 100 Hz and 100 KHz. An increase in both resistance and impedance of the sensors is observed with increase in temperature. The temperature coefficients of the sensors having resistances $$\sim 470$$ $$\Upomega$$ and $$\sim 890$$ $$\Upomega$$ were $$1.0\%\,{}^{\circ }\hbox {C}^{-1}$$ and $$1.9\%\,{}^{\circ }\hbox {C}^{-1}$$ , respectively, when evaluated for temperatures ranging from 30 to $$65^{\circ }\hbox {C}$$ . For applied pressure 0 $$\hbox {kgf\,cm}^{-2}$$ to 0.1 $$\hbox {kgf\,cm}^{-2}$$ and displacement 0 to 110 $$\upmu \hbox {m}$$ the resistance of the multifunctional sensor decreases 1.3 to + 12.7 times (from 6730 $$\Upomega$$ to 5210 $$\Upomega$$ and 3410 $$\Upomega$$ to 269 $$\Upomega$$ ) and 3.18 to 7.53 times (2235 $$\Upomega$$ to 702 $$\Upomega$$ and 6787 $$\Upomega$$ to 901 $$\Upomega$$ ), respectively. With increased thickness of OD layer from 300 $$\upmu \hbox {m}$$ to 570 $$\upmu \hbox {m}$$ , the output resistance and impedance of the sensors as a function of temperature also increased, exhibiting the improved sensitivity, however, at the expense of decreased pressure and displacement response of the sensors. Therefore, the thickness of OD film can be used as a design parameter for a desired sensitivity value to cater a particular application. The proposed multifunctional sensor can be a good candidate to measure temperature, pressure, and displacement of an industrial unit, such as flex bonding head because it offers light weight, simpler design, low maintenance, and eventually low cost.

Carbon Nanotube Metal Polymer Composites for Flexible Active Interconnects

We report on the fabrication of metal polymer carbon nanotube (MPCNT) composites for flexible active interconnects. Our experiments demonstrated that such CNTs-reinforced polymer-metal composites have several times higher tolerance to bending strains than the metal-polymer composites without the CNTs layer. Since CNT-polymer layer electrically separated from the metal layer until destructive breakdown, it is feasible to fabricate electronic components isolated from the metal layer in MPCNT composites. Thus, the MPCNT composites-based interconnects could be utilized as a platform for CNTs-based environment monitoring sensors and CNT Thin Film Transistors (TFTs) with applications in Internet of Things (IoT), autonomous vehicle systems, and wearable electronics. To estimate the electrical characteristics of the CNT-polymer based electronic devices, we developed the compact Unified Charge Control Models (UCCM) for single CNT field effect transistors (FETs) and CNT mat TFTs. The UCCM models were validated by comparison of the simulated results with different experimental data reported by other groups. The models could be widely used for device simulation and circuit design for developing flexible active interconnects and electronic components based on the single CNTs, CNT mats, and MPCNT composites.

Fabrication of single-walled carbon nanotubes in the channels of CoAPO-5 membrane by low-temperature hydrocracking

Abstract The defect-free CoAPO-5 membrane was fabricated on the porous α-Al2O3 substrate by using in-situ crystallization, and the prepared CoAPO-5 membrane was used as the template for the preparation of single-walled carbon nanotubes (SWCNTs) inside the liner channels (0.73 nm in diameter) by low-temperature hydrocracking, utilizing the organic precursor (tripropylamine) as the carbon source. The results of X-ray diffraction and scanning electron microscopy indicated that the synthesized membrane covered tightly on the α-Al2O3 substrate was 50 μm in thickness, which was composed of well-intergrown and randomly oriented CoAPO-5 molecular sieves. According to the characterization using high-resolution transmission electron microscopy, polarized Raman scattering and thermal-gravimetric analysis, 0.4 nm SWCNTs were synthesized inside the zeolitic channels of the CoAPO-5 membrane, and 45.47% tripropylamine were successfully converted into SWCNTs after hydrocracking for 12 h at 350 °C. On the basis of N2 adsorption/desorption isotherms for the CoAPO-5 molecular sieves and SWCNTs/CoAPO-5 composite material, it can be concluded that the fraction of channels not containing SWCNTs in the resulting SWCNTs/CoAPO-5 composite membrane is small. The results of single-component pervaporation demonstrate that the inter-crystal defects in the as-synthesized SWCNTs/CoAPO-5 composite membrane are negligible.

Highly efficient removal of Eu3+ ions using carbon nanotubes-based polymer composites synthesized from the combination of Diels-Alder and multicomponent reactions

Abstract The removal of environmental pollutants through adsorption by nanomaterials or nanocomposites has attracted great attention over the past few decades. In this work, a novel strategy that combined with Diels-Alder (DA) and multicomponent reactions has been developed to fabricate carbon nanotubes (CNT) based polymer composites and their potential utilization for removal of rare earth ions from wastewater. First, the amino groups were introduced on the CNT through the DA reaction between CNT and furfurylamine. The obtained amino group-terminating CNT composites (named as CNT-FFA) were further conjugated with the polymers through Kabachnik–Fields (KF) reaction. To evidence the successful fabrication of these CNT based polymer composites, a variety of characterization methods, such as Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS), were used to measure the chemical structure, compositions and thermal stability of CNT based polymer composites. Furthermore, a series of adsorption experiments were implemented to explore the influence of contact time, temperature, initial concentration and pH for adsorption behavior. The results demonstrated that the adsorption capability of resultant CNT based composites (CNT-FFA-PAA) towards Eu3+ ions is about 130.8 mg g−1, which is much greater than that of pristine CNT (46.67 mg g−1). The above results demonstrated that the method described in this work is a facile and effective tool for fabrication of functional CNT polymer composites, which possess promising prospects for environmental adsorption applications. More importantly, this method in this work could be generally applied in the surface modification of other materials for various applications.