Preparation Of Multi-walled Carbon Nanotubes Research Articles

Preparation of Multi-walled Carbon Nanotubes and Graphene Oxide Incorporated MIL-101(Cr)/Sulfasalazine Composite for Adsorptive of TPA, BA, and p-tol from Wastewater

Preparation of Multi-walled Carbon Nanotubes and Graphene Oxide Incorporated MIL-101(Cr)/Sulfasalazine Composite for Adsorptive of TPA, BA, and p-tol from Wastewater

Wearable electrochemical sensor based on bimetallic MOF coated CNT/PDMS film electrode via a dual-stamping method for real-time sweat glucose analysis

Non-invasive wearable sweat glucose sensors are expected to be highly desirable for personalized diabetes management. Therefore, developing facile, convenient, and scalable manufacturing method of such wearable sensors is urgently needed. Herein, we report a simple and low-cost stamping-vacuum filtration dry transfer (SVFDT) method for construction of a wearable sweat glucose electrochemical sensor. In this patch, a three-electrode array template was made by using a polyvinyl chloride (PVC) stamp, followed by the preparation of multiwalled carbon nanotubes (MWCNTs)/polydimethylsiloxane (PDMS) (MP) film electrode using the vacuum-filtration dry transfer method. In addition, for further enhancing the conductivity of the electrode, another similar stamp with a raised surface dipping carbon nanotubes (CNTs) conductive coating was stamped on the surface of the MP electrode to obtain CNTs/MWCNTs/PDMS (CMP) electrode. CMP electrode was modified with the enzyme-like Ni-Co metal-organic framework (MOF) material which showed good electro-catalytic activity and achieved high sensitivity for glucose detection with a low detection limit of 6.78 μM and a wide linear range of 20 μM - 1.1 mM. More importantly, the Ni-Co MOF modified CMP (NCMP) electrode also displayed high stability under stretching and bending conditions. Finally, the sweat absorbent cloth was combined with the NCMP film electrode to form a wearable flexible electrochemical sensor patch, which could adhere to the skin to enrich sweat and realize real-time detection of sweat glucose with high accuracy. This SVFDT method can also be applied to the fabrication of other electronic devices.

Preparation of Multi-walled Carbon Nanotubes with Ni/SiO2 Composites

Using carbon monoxide as carbon source to manufacture Multi-walled carbon nanotubes on the supported of Ni/SiO2 by chemical vapor deposition. The effects of nickel loading and raw gas to carbon nanotubes were studied. When the content of Ni is 5%, the yield of carbon is very low. As the content of Ni increases from 5% to 35%, the yield gradually increases. When Ni loading exceeds 35%, the yield of carbon decreases. Through the TEM, HRTEM and XRD to characterized carbon nanotubes. The results showed that the morphology of carbon nanotubes became worse with the Ni conten increased In terms of yield and quality,the best synthesis temperature is 600°C. In the absence of hydrogen in the feedgas, the diameter of carbon nanotubes is in the narrow range of 10 to 20 nm. When hydrogen is introduced into the system, the amount of carbon increases, but the form deteriorates.

Preparation of Multiwalled Carbon Nanotubes: Electrochemically Treated Pencil Graphite Electrodes for Nanomolar Detection of L‐Tryptophan in Complex Samples

AbstractThe present work reports a sensitive and simple sensor based on an electrochemically treated pencil graphite electrode (pre‐PGE) modified with multi‐walled carbon nanotubes (MWCNTs) for electrochemical determination of L‐tryptophan (L‐Try) detection in the presence of uric acid. Electrochemical and physical characterizations of the MWCNTs/pre‐PGE were investigated using cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) techniques. Under the optimized conditions, the linear working range was 0.030–200.0 μM with a limit of detection of 9.0 nM using the differential pulse adsorptive stripping voltammetry (DPAdSV) method. The proposed sensor exhibited good sensitivity, repeatability, reproducibility, and stability. The MWCNTs/pre‐PGE were successfully applied to L‐Try determination in commercial poly‐amino acid supplements with good recovery and accuracy.

Carbon Nanotube Ink Dispersed by Chitin Nanocrystals for Thermoelectric Converter for Self-Powering Multifunctional Wearable Electronics.

The screen-printing process of conductive ink can realize simple and large-scale manufacture of micro/nano patterns for producing wearable electronic products. Herein, chitin nanocrystals (ChNCs) are used as a dispersant for the preparation of multiwalled carbon nanotube (MWCNT) ink with high viscosity and uniformity by ultrasound treatment. ChNCs can interact with MWCNT in noncovalent ways, including π-π and hydrophobic interactions. ChNCs/MWCNT (CCNT) ink does not aggregate even after standing for 3 months with a maximum MWCNT concentration of 33mg mL-1 and dispersion efficiency of 91.1%. Using CCNT ink, a paper-based thermoelectric generator (TEG) is manufactured by screen-printing technology. With good thermoelectric and strain sensing properties, CCNT coated paper can stably collect human energy at room temperature to realize self-powering. The CCNT coated paper-based TEG can convert thermal voltage signals into musical notes, monitor the changes in human behavior and respiratory rate, and monitor joint movements. Moreover, CCNT coated paper has no cytotoxicity by CCK-8 and live/dead staining. This work puts forward a strategy of green preparation of MWCNT-based ink by adding renewable chitin, which opens up a new way to apply MWCNT-based ink in self-powering wearable multifunctional sensors.

PEG@ Carbon Nanotubes Composite as an Effective Nanocarrier of Ixazomib for Myeloma Cancer Therapy

In this work, the preparation of a PEG@ multi-walled carbon nanotubes (MWCNTs) composite has shown a great potential effect in tumor therapy using graphite powder at room temperature. PEGylated MWCNTs were created and used as a carrier for targeting the antineoplastic drug Ixazomib to myeloma cancer cells (abnormal plasma cells). Ixazomib (MLN2238) was covalently encapsulated into functionalized carbon nanotubes modified with polyethylene glycol (PEG 600) to obtain MWCNTs-PEG-MLN2238. The Ixazomib@ MWCNTs-PEG composite shows promising results as an effective nanocarrier and using a small amount of MWCNTs-PEG-Ixazomib that has a low toxicity compared with that of Ixazomib alone. A multifunctional MWCNTs-PEG-Ixazomib composite is used to test biological effects on multiple myeloma cell lines RPMI 8226 using the MTT assay to enhance treatment efficiency. The cytotoxicity of free Ixazomib citrate (69% cell viability of RPMI8226 cells) was higher than that of MWCNTs-PEG-Ixazomib (91% cell viability) at the same maximum concentration of Ixazomib citrate (50 µg/ml). In this work, we performed a study of preparation of MWCNTs with an acceptable Ixazomib loading efficiency and determination of the drug systemic toxicity for the first time. In this study, the preparation of MWCNTs with acceptable Ixazomib loading efficiency and determination of the drug systemic toxicity was performed for the first time. The MTT assay results show decreasing the toxicity of Ixazomib after loading with the MWCNTs-PEG composite. The MWCNTs-PEG @ Ixazomib show promising results as an effective carrier of Ixazomib and lead to a decrease in the cost of using Ixazomib.Graphical

Preparation of multi-walled carbon nanotubes coated with CoFe2O4 nanoparticles and their adsorption performance for Bisphenol A compound

In this study, the adsorption performance and characterization properties of the multi-walled carbon nanotubes were improved by coating this material with CoFe2O4 nanoparticles. The resultant adsorbent (MWCNTs/CoFe2O4) was first synthesized using solvothermal co-precipitation and Electrophoretic precipitation methods, characterized, then used in the adsorption system of Bisphenol A (BPA) wastewater. The influence of pH (3–11), initial BPA concentration (25–100 mg/L), MWCNTs/CoFe2O4 dosage (0.1–1.5 g/L), contact time (0–240 min), and temperature (283–328 K) on BPA removal adsorption onto MWCNTs/CoFe2O4 was investigated. Better results for BPA removal ( 99%) were achieved in acidic conditions (pH = 3), and the equilibrium state was reached at 150 min of contact time. The Langmuir and pseudo-second order models were suitable to describe the adsorption isotherm and kinetics, as verified by goodness-of-fit analysis. The adsorption of BPA molecules onto MWCNTs/CoFe2O4 active groups was occurred via chemisorption interaction, based on the analyses of Dubinin-Radushkevitch and Freundlich isotherms. Moreover, the endothermic, favorable, and spontaneous nature of BPA adsorption onto MWCNTs/CoFe2O4 was proved by thermodynamic studies. Reusing MWCNTs/CoFe2O4 after 6 cycles showed a ten percent reduction in adsorption capacity, which indicates the good stability and reusability. The maximum adsorption capacity of MWCNTs/CoFe2O4 for BPA adsorption from Langmuir model was 416.6 mg/g, which is much higher than that of reported other adsorbents used for the same purpose. This study revealed that MWCNTs/CoFe2O4 is a promising adsorbent for BPA adsorption with high removal efficiency, easy separation, and good reusability properties.

Multi-walled carbon nanotubes and chromium ferrites nanoparticles nanohybrids as anode materials for lithium-ion batteries

Two-step synthesis route was opted for the preparation of multi-walled carbon nanotubes (MWCNTs) and chromium ferrites (CrFe2O4) nanoparticles nanohybrids. In the first step, CrFe2O4 nanoparticles were prepared through co-precipitation route, while in second step an ultra-sonication assisted route was chosen for dispersion of these nanoparticles on the surface of MWCNTs. A polar solvent toluene was used for the dispersion of these nanoparticles and MWCNTs to obtain the final product (MWCNTs)x/CrFe2O4; x = 0–20 wt% nanohybrids. X-rays diffraction (XRD) confirmed the corresponding crystal structures of MWCNTs and (MWCNTs)x/CrFe2O4 nanohybrids. It was evident from scanning electron microscopy (SEM) that CrFe2O4 nanoparticles were evenly distributed on the surface of MWCNTs. The morphology of (MWCNTs)x/CrFe2O4 nanohybrids confined the pulverization of active material that ensured electron-ion transport efficiency during lithiation and de-lithiation. Consequently, these nanohybrids exhibited prime cyclic performance at different values of current densities. These (MWCNTs)x/CrFe2O4 nanohybrids revealed better Li+ storage properties with high Coulombic efficiency ‘Ce’, better cyclic stability, improved reversible specific discharge capacity after 100 cycles and enhanced rate capability. Thus, current study offered a low-cost and facile synthesis route to prepare these nanohybrids as anode materials for lithium-ion batteries.

Optimized protocol for the preparation of multi-walled carbon nanotube:polystyrene transducers for electrochemical sensing

A practical method is presented to prepare films of a composite material constituted of multi-walled carbon nanotubes (MWCNTs) and polystyrene (PS) that are used for transduction applications. The method, which can be carried out by employing usual lab equipment, is simple, low-cost, rapid, and nonpolluting. Furthermore, it is compatible with microelectronic fabrication technology and is scalable for mass production. For designing this method, we studied how the number of drop-casted composite layers, the temperature used for curing the samples, and the duration of this thermal treatment influence on the electrochemical performance of a Si/SiO2/Au/MWCNT:PS electrode. The optimum electrochemical responses of the Si/SiO2/Au/MWCNT:PS electrode were obtained with films prepared with four layers of MWCNT:PS composite, each cured at 80 °C for 15 min. Under these conditions, the MWCNT walls are exposed and readily accessible for subsequent functionalization.

Preparation of multi-walled carbon nanotubes based magnetic multi-template molecularly imprinted polymer for the adsorption of phthalate esters in water samples.

Taking the advantages of surface imprinting, multi-template imprinting and magnetic separation, a novel magnetic multi-template molecularly imprinted polymer (mag-MMIP@MWCNTs) was prepared by using MWCNTs as support material, Fe3O4 as magnetic core, and dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP) as template molecules. This composite was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), and the Brunauer-Emmett-Teller (BET) analysis, and was used for the simultaneous adsorption of DMP, DEP, and DBP in aqueous solution. The effects of solution pH, contact time, PAEs initial concentration, temperature, adsorption selectivity, and reusability were investigated and discussed in detail. The results demonstrated that mag-MMIP@MWCNTs exhibited fast kinetics, good magnetic separation, and excellent selectivity for the adsorption of three phthalate esters (PAEs). The adsorption kinetics followed pseudo second-order kinetic model and the adsorption thermodynamics followed Langmuir isothermal model very well, and the maximum adsorption capacities (Qmax) of DMP, DEP, and DBP were obtained as 0.95, 1.38, and 7.09 mg g-1, respectively. The Scatchard analysis revealed that the template-polymer system had a two-site binding behavior. The adsorption thermodynamic studies indicated that the adsorption processes were exothermic and spontaneous, and dominated by physical adsorption relying on hydrogen bond, hydrophobic interaction, and van der Waals force. Mag-MMIP@MWCNTs also showed good reproducibility and reusability for simultaneous adsorption of the three PAEs. The potential application of mag-MMIP@MWCNTs was proved by the removal of DMP, DEP, and DBP spiked in environmental water samples.

Preparation and characterization of carbon nanotubes by pulsed laser ablation in water for optoelectronic application

Abstract In the present work, preparation of multi-walled carbon nanotubes (MWCNTs) and carbon nanoparticles (CNPs) by using pulsed laser ablation of a graphite target in water without using catalyst was demonstrated. The effect of laser wavelength on the optical absorption and structural properties has been studied. X-ray diffraction (XRD) data shows the synthesized CNTs were polycrystalline and a peak related to the diamond structure was observed. Scanning electron microscope (SEM) investigation displays that the average diameter of CNTs synthesized with 532 nm was 20 nm and few micrometers in length, while the CNTs synthesized with 1064 nm have an average diameter of 75 nm and lengths of few sub-micrometers. Some of CNPs were noticed to deposit on the CNTs. Transmission electron microscope (TEM) was used to study the morphology of MWCNTs. Raman spectra confirm formation of MWCNTs during the presence of three peaks belonged to D-band, G-band and 2D-band. The intensity ratio of IG/ID is larger than unity for MWCTs prepared by two laser wavelengths. The colloidal MWCNTs prepared by 532 nm laser pulses showed higher absorption than that of MWCNTs prepared with 1064 nm. The current-voltage characteristics and responsivity of hybrid In/p-MWCNTs/n-Si heterojunction photodetectors prepared at different CNTs film thicknesses were investigated at room temperature. The responsivity of hybrid MWCNTs/n-Si photodetector has two peaks of response, the first peak was found at 650 nm and the second peak located at 850 nm. The maximum responsivity was 0.53 A/W at 532 nm was found for the photodetector fabricated with 532 nm laser. The energy band diagram of MWCNTs/Si heterojunction was constructed under illumination condition.

Preparation of Multi-Walled Carbon Nanotubes Supported Zinc Oxide Catalyst for Transesterification of Kesambi (Schleichera oleosa) Oil

In this work, multi-walled carbon nanotubes supported zinc oxide (ZnO/MWCNTs) as a heterogeneous catalyst for transesterification had been successfully prepared via the modified Stober-like synthesis method. The effect of calcination temperature during the catalyst preparation towards reaction was investigated. These catalyst was also characterized by X-ray diffraction (XRD) analysis, N2 adsorption-desorption analysis followed by Brunauer- Emmett-Teller (BET) calculation to determine the total surface area, and scanning electrone microscopy with energy dispersive x-ray spectroscopy (SEM-EDX). Transesterification of kesambi (Schleichera oleosa) oil also had been done to test the activity of the prepared catalysts. However, the quantity of dispersed zinc oxide (ZnO) on multi-walled carbon nanotubes (MWCNTs) are quite small that is lower than 5 %wt. It produces low conversion of transesterification after 3 hours reaction that is under 15% of conversion.

Analysis of adsorption properties of magnetic composites: preparation of multi-walled carbon nanotubes

Analysis of adsorption properties of magnetic composites: preparation of multi-walled carbon nanotubes

Synthesis of Poly(methyl methacrylate) Grafted Multiwalled Carbon Nanotubes via a Combination of RAFT and Alkyne-Azide Click Reaction

An efficient synthesis route was developed for the preparation of multiwalled carbon nanotube (MWCNT) nanohybrids using azide-terminated poly(methyl methacrylate) (PMMA) via a combination of reversible addition fragmentation chain transfer (RAFT) and the click reaction. A novel azido-functionalized chain transfer agent (DMP-N3) was prepared and subsequently employed to mediate the RAFT polymerizations of methyl methacrylate (MMA). The RAFT polymerizations exhibited first-order kinetics and a linear molecular weight dependence with the conversion. The kinetic results show that the grafting percentage of PMMA on the MWCNTs surface grows along with the increase of the reaction time. Even at 50 °C, the grafting rate of azide-terminated PMMA is comparatively fast in the course of the click reaction, with the alkyne groups adhered to MWCNTs in less than 24 h. The successful functionalization of PMMA onto MWCNT was proved by FTIR, while TGA was employed to calculate the grafting degree of PMMA chains (the highest GP = 21.9%). Compared with the pristine MWCNTs, a thicker diameter of the MWCNTs-g-PMMA was observed by TEM, which confirmed the grafted PMMA chain to the surface of nanotubes. Therefore, the MWCNTs-g-PMMA could be dispersed and stably suspended in water.

Dynamic properties of elastomer composites filled with multiwalled carbon nanotubes

The paper studies the influence of multiwalled carbon nanotubes (MWCN) on vulcanizing and dynamic properties under shear and oscillating load. It was found that, despite the lack of preliminary preparation of MWCN, when their concentration increase the dynamic properties also increase under an oscillating load in highly elastic state. Thus, it is possible to use MWCN producing elastomer materials with improved properties.

Green Preparation of Multiwalled Carbon Nanotubes Supported Pd and Cu Nanoparticles with Novel Vic-dioxime Metal Complexes

The preparation of multi-walled carbon nanotubes (MW-CNTs) supported Cu and Pd nanoparticles on utilizing a supercritical carbon dioxide deposition method were investigated. Novel vic-dioxime complexes of Cu(II) and Pd(II) were used as metallic precursors. The ligand used in these precursors were 4-(trifluoromethyl)aniline-vic-dioxide. Ligand and metal complexes were synthesized and identified with various analyses method including 1H and 19F NMR, FT-IR, UV-Vis, elemental analysis and magnetic susceptibility. MW-CNTs supported Pd and Cu nanoparticles were characterized by high-resolution transmission electron microscopy (HR_TEM), X-ray diffraction (XRD) and scanning electron microscopy with EDX (SEM_EDX). SEM_EDX and HR_TEM micrographs showed a homogenous distribution of reasonably well-dispersed Cu and Pd nanoparticles on the support. The nature and crystallinity of the nano metal particles were confirmed using XRD. Crystallite sizes ranged from 7-20 nm for palladium and 20-30 nm for copper. This study demonstrated that these oxime complexes are suitable precursors for the preparation of supported nanoparticles using a supercritical carbon dioxide deposition method. 

Preparation of Multiwall Carbon Nanotubes with Zinc Phthalocyanine Hybrid Materials and Their Nonlinear Optical (NLO) Properties.

Hybrid material of multi walled carbon nanotubes (MWCNT)-zinc phthalocyanine (ZnPcs) (MWCNT-ZnPc) composites were synthesized and compared with ZnPc. Nonlinear optical properties of MWCNT-ZnPc and ZnPc were studied. The synthesized MWCNT-ZnPc characterized by UV-visible absorption spectroscopy, photoluminescence and TEM. Their nonlinear optical properties were measured through Z-scan technique with 800 nm, 110 fs, 1 kHz Ti:Sapphire laser and 532 nm, 30 ps and 10 Hz Nd:YAG laser. The results showed that phthalocyanines were anchored onto the surface of the multi walled carbon nanotubes by using TEM. Photoluminescence spectra had shown quenching in emission of MWCNT-ZnPcs hybrid material due to the energy transfer. Reverse saturable absorption in MWCNT-ZnPcs hybrid material was compared with pure phthalocyanine, which had shown an increase in nonlinear absorption coefficient with 532 nm and reduction with 800 nm. The results concluded that MWCNT and MWCNT-ZnPc can be used as effective optical limiters.

Synthesis and characterisation of multi-walled carbon nanotubes (MWCNTs)

ABSTRACTCarbon nanotubes are one of the major research areas in the field of nanotechnology, due to its mechanical and electro-conductive properties in the field of engineering and medical sciences. This paper focuses on preparation of multi-walled carbon nanotubes (MWCNTs) for the mass production using thermal catalytic chemical vapour deposition method. The synthesis of MWCNTs was made by breakdown of acetylene (C2H2) gas and Fe/MgO acting as catalyst. The surface morphology and structure of MWCNTs were characterised by scanning electron microscopy (SEM). Also phase identification and crystalline size of the nanopowder were determined by XRD. The particle size of MWCNTs was verified by SEM analysis and it was in the range of 20–30 nm and elemental analysis was carried out through energy dispersive analysis X-ray. Furthermore, thermal decomposition of the material property was studied by thermogravimetric analysis.

Electrical and structural properties of multi-walled carbon nanotube–doped polymer electrolyte for photo electrochemical device

The present investigation deals with the preparation of multi-walled carbon nanotube (MWCNT)-doped plasticized polymer electrolyte. The nanocomposite has been prepared using solution casting method. Complex impedance spectroscopy study revealed the utmost room temperature conductivity of 5.6 × 10−4S/cm when optimized plasticized polymer electrolyte (poly(ethyl methacrylate)+30% sodium iodide+60% ethylene carbonate) was doped with 7% MWCNT. Temperature dependence of conductivity showed Arrhenius behavior. The surface morphology and crystalline–amorphous deviation of the composite was observed using scanning electron microscope. Perfect complexation of various components of the composite was confirmed from Fourier-transform infrared spectroscopy and X-ray diffraction (XRD) data. The transference number measurement was done to calculate the proportionate amount of ionic and electronic conductivity. A dye sensitized solar cell has been fabricated using maximum ionic conductivity of solid polymer electrolyte and its electrical parameters measured at 1 sun condition.

Facile Fabrication of Platinum-Cobalt Alloy Nanoparticles with Enhanced Electrocatalytic Activity for a Methanol Oxidation Reaction

Decreasing the cost associated with platinum-based catalysts along with improving their catalytic properties is a major challenge for commercial direct methanol fuel cells. In this work, a simple and facile strategy was developed for the more efficient preparation of multi-walled carbon nanotube (MWCNT) -supported Pt/CoPt composite nanoparticles (NPs) via solution plasma sputtering with subsequent thermal annealing. Quite different from general wet synthesis methods, Pt/CoPt composite NPs were directly derived from metal wire electrodes without any additions. The obtained Pt/CoPt/MWCNTs composite catalysts exhibited tremendous improvement in the electro-oxidation of methanol in acidic media with mass activities of 1719 mA mg−1Pt. This value is much higher than that of previous reports of Pt-Co alloy and commercial Pt/C (3.16 times) because of the many active sites and clean surface of the catalysts. The catalysts showed good stability due to the special synergistic effects of the CoPt alloy. Pt/CoPt/MWCNTs can be used as a promising catalyst for direct methanol fuel cells. In addition, this solution plasma sputtering-assisted synthesis method introduces a general and feasible route for the synthesis of binary alloys.