간행물

Carbon Letters KCI 등재 Carbon letters

권호리스트/논문검색
이 간행물 논문 검색

권호

Vol.29 No.1 (2019년 2월) 11

ORIGINAL ARTICLE

1.
2019.02 구독 인증기관 무료, 개인회원 유료
Carboxylated multi-wall carbon nanotubes (MWCNTs-COOH) was functionalized with 3-amino-5-phenylpyrazole (MWCNTs- f) and characterized by FTIR, EDX, SEM, XRD and TGA. The MWCNTs-COOH and MWCNTs-f were used for the adsorption of Cd(II), Hg(II), and As(III) ions from aqueous solutions. Additionally, to study the influence of pH, adsorbent dose, and initial ions concentration on the adsorption process, the central composite design (CCD) was applied. The quadratic model was used for analysis of variance and indicated that adsorption of metal ions strongly depends on pH. Timedependent adsorption can be described by the pseudo-second-order kinetic model, and adsorption process was modeled by Langmuir isotherm for the adsorbents. Thermodynamic analysis showed that the adsorption of Cd(II), Hg(II) and As(III) ions were spontaneous and endothermic. Moreover, the competitive adsorption capacities of the heavy metal ions were slightly lower than noncompetitive ones. The same affinity order was observed under noncompetitive and competitive adsorption: As(III) > Cd(II) > Hg(II) in the case of MWCNTs-f. Desorption study revealed the favorable regeneration ability of adsorbents powders, even after three adsorption–desorption cycles.
5,500원
2.
2019.02 구독 인증기관 무료, 개인회원 유료
The growing demand for nano-structured composite materials and sustainable processes for next generation CO2 capture technologies has necessitated the need to develop novel and cost-effective synthetic routes for solid CO2 adsorbents based on hypercross-linked polymers (HCPs) and reduced graphene oxide (RGO) microporous sorbent materials with improved physico-chemical properties. The most important selection is modification of the synthesized microporous sorbent materials by the incorporation of RGO, giving rise to composite materials that combine the properties of both. These hybrid materials will be of great potential for carbon capture and storage (CCS) applications, especially for post-combustion CO2 capture, owing to the increase in CO2 capturing efficiency and selectivity to CO2 compared to other flue gases. Herein, we report a facile and effective approach for fabrication of HCPs-supported reduced graphene oxide composites. The microporous HCPs was synthesized using 4,4′-bis(chloromethyl)-1,1′-biphenyl monomer by Friedel–Crafts alkylation. The RGO was prepared by modified Hammers method. The as-synthesized composites were characterized by TEM, SEM, FTIR, TGA and N2 adsorption–desorption isotherm. The HCP/RGO composite showed maximum CO2 adsorption of 5.1 wt% than the HCPs alone at 40 °C and 1 atm.
4,000원
3.
2019.02 구독 인증기관 무료, 개인회원 유료
Plasma-sprayed HA coatings on metallic implants are widely used for clinical applications. However, typical lamellar structure along with plasma-sprayed coatings usually leads to weak inter-splat adhesion and impair their mechanical properties. In this research, graphene nanosheet (GNS) reinforced HA coatings were fabricated using plasma spray; these GNSs retained their original structure and distributed homogeneously in the as-sprayed coatings. On the basis of instrumented microindentation tests with and without multiple partial unloading, as compared with the monolithic HA coating, the inter-splat friction force increased by ~ 8.7% for the 1.0 wt% GNS/HA coating, and it slightly decreased to ~ 6.5% for the 2.0 wt% GNS/ HA coating due to GNS agglomeration. Meanwhile, the added GNSs contributed greatly to the indentation yield strength of the HA coatings. These results illustrated that these embedded GNSs at splat boundaries are potential in splat-boundary strengthening and resisting splat sliding.
4,000원
4.
2019.02 구독 인증기관 무료, 개인회원 유료
residue as the raw material. As one of the preconceived raw material to produce high-quality coal-based carbon material, the changes of structure of CLP during liquid-phase carbonization process have been detailed investigated in this study. Actually, FTIR and curve-fitted method were used to quantitative analyze the aromaticity index (Iar), the ratio of CH3/ CH2, and basic functional groups (C=C, C=O, and C–O) of CLP and its liquid-phase carbonization products. Polarizing microscope, XRD and curve-fitted methods were used to characterize the microstructures of CLP and derived products. The results show that, branched chain and C=O group are the active reaction point in liquid-phase carbonization process. What’s more, 450 °C is a critical temperature point on the severe thermal polycondensation of CLP. The XRD and curve-fitted analysis of CLP and its liquid-phase carbonization products shows that, the stacking height (Lc), parallel layers (N), and the numbers of aromatic ring in each layer (n) are gradually larger with the improve of liquid-phase carbonization temperature.
4,000원
5.
2019.02 구독 인증기관 무료, 개인회원 유료
We have studied a method to prepare polydopamine-modified reduced graphene oxide-supported Pt nanoparticles (Pt– PDA–RGO). The Pt–PDA–RGO nanocomposites were synthesized by a wet-coating process, which was induced by selfpolymerization of dopamine. As an eco-friendly and versatile adhesive source in nature, dopamine could be easily adhered to surfaces of organic material and inorganic material via polymerization processes and spontaneous adsorption under weak alkaline pH conditions. To apply the unique features of dopamine, we synthesized Pt–PDA–RGO nanocomposites with a different quantity of dopamine, which are expected to preserve the improved Pt adsorption on graphene, resulting in the enhanced electrocatalytic performance. The morphology and micro-structure were examined by field emission scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Compared to pristine Pt–deposited RGO (Pt–RGO), Pt–PDA–RGO (30 wt% dopamine against RGO) nanocomposites showed a superior electrochemical active surface area for a methanol oxidation. This could be related to the fact that the optimized c
4,000원
6.
2019.02 구독 인증기관 무료, 개인회원 유료
Effects of multi-walled carbon nanotube (MWCNT) type and flow type (shear and elongational flow) on the electrical conductivity of polycarbonate (PC)/MWCNT nanocomposites were investigated. Two different MWCNTs produced a huge difference in electrical conductivity in an injection molded PC/MWCNT nanocomposite. It was observed that MWCNTs having a higher aspect ratio provide much lower electrical conductivity in injection molded PC/MWCNT nanocomposites while the conductivities of compression molded samples from two different MWCNTs were the same. We found that this is due to a difference in the deformability of the two MWCNTs. Nanocomposite samples prepared at a higher extensional rate and shear rate showed lower electrical conductivity. This is attributed to flow induced orientation of the MWCNTs. The experimental results were discussed in relation to variation in the tube–tube contact due to the change of the MWCNT orientation.
4,000원
7.
2019.02 구독 인증기관 무료, 개인회원 유료
Perennial need for bactericides requires cost-effective nanomaterials with strong antibacterial activities even in the absence of external irradiation. Hence, in this work, we have synthesized f-CFT (fluorinated TiO2- doped, glycine-functionalized MWCNTs) and have studied its antibacterial activities. Both gram-negative and gram-positive bacteria were analyzed in the absence of photo-activation. Zone of inhibition of 15 mm for S. aureus, and 11 mm for P. aeruginosa was observed for f-CFT owing to the synergistic bactericidal properties of functionalized MWCNTs, fluorine and nano-TiO2. Anatase phase TiO2 with average crystallite size as 35 nm was observed in XRD. Scanning electron microscopic images showed uniform mixed cubic structures. Hydroxyl groups observed in FT-IR along with the glycine MWCNTs interface aid the inhibition of bacterial growth even in the absence of photo activation. A desired higher gram-positive bacterial inhibition opens new gates for better antibacterial agents.
3,000원
8.
2019.02 구독 인증기관 무료, 개인회원 유료
The composites of carbon nanotube (CNT) supported by Sn-doped MnO2 with enhanced capacitance have been fabricated with varying dopant concentrations. The composites have been subjected to physiochemical, configurational, and morphological analyses by FTIR, UV–Vis spectroscopy, X-ray diffraction and field emission scanning electron microscopy, high resolution transmission electron microscopy and selected area electron diffraction studies. The electrochemical performance of the composite has been evaluated by cyclic voltammetry and charge/discharge techniques. Highest specific capacitances of 940 F g−1 at a current density of 0.35 A g−1 and 927 F g−1 at 5 mV s−1 in 1 M Na2SO4 electrolyte solution was achieved in the case of 5% Sn doped composite. Moreover, the electrode demonstrated good cycling performance and retaining 79.7% of the initial capacitance over 3000 cycles. The superior electrochemical performance is accredited mainly to the porous sheath hierarchical architecture, which consist of inter connected MnO2 nanoneedles uniformly coated over the CNT surface. This peculiar architecture is responsible for fast ion/electron transfer and easy access of the active material.
4,200원
9.
2019.02 구독 인증기관 무료, 개인회원 유료
High-quality and solution processable graphene sheets are produced by a simple electrochemical exfoliation method and employed as a high-power anode for lithium-ion batteries (LIBs). The electrochemically exfoliated graphene (EEG) composed of a few layers of graphene sheets, have low oxygen content and high C/O ratio (~ 14.9). The LIBs with EEG anode exhibit ultrafast lithium storage and excellent cycling stability, but low initial efficiency. The excellent rate capability and cycling stability are attributed to the favorable structural and chemical properties of the EEG, but the large irreversibility needs to be overcome for practical applications.
4,000원
10.
2019.02 구독 인증기관 무료, 개인회원 유료
In this study, the different effects of ultrasonic surface treatment on rice husk carbon (RHC) were studied. The RHC was treated by ultrasound in water, silane, and polyphosphoric acid. Particle size, chemical changes of the surface, dispersion, and surface area were all investigated. The ultrasonic treatment in acid increased the hydrophilicity of RHC. The ultrasonic treatment in silane produced silanol having amphiphilic property. The surface treatment of RHC in a water and acid medium with ultrasound increased the surface area and pore volume of RHC. Therefore, it is expected that the ultrasonically treated RHC as a biofiller is an effective substitute to commercial filler. This would have a positive effect both economically and environmentally.
4,000원
11.
2019.02 구독 인증기관 무료, 개인회원 유료
Aimed at determining whether China’s active carbon emission reduction policy can respond to the threat of carbon tariff of the USA, this study proposed two kinds of carbon tax schemes for the USA and China, same carbon tax policy and a differential carbon tax policy. Four scenarios are set: the USA only charging carbon tax on domestic products; the USA charging carbon tax on domestic products and carbon tariff on imported products from China; the USA and China taking the same carbon tax policy on domestic products; the USA and China taking the differential carbon tax policy on their domestic products. Global Trade Analysis Project Energy model is applied to discuss whether China’s active measure to reduce carbon emissions can be an effective solution to the threat of carbon tariff of the USA. The research results show that China’s active measure of the same carbon tax policy as the USA is not effective to cope with carbon tariff of the USA. However, it is an effective measure to take a differential carbon tax policy. The specific policy implications of the study are discussed in conclusion.
4,000원