Purnendu, Soumitra Satapathi^*

Journal of Renewable Materials, Vol.5, No.2, pp. 96-102, 2017, DOI:10.7569/JRM.2016.634134

Abstract Graphene-based 3D porous xerogel was designed through molecular self-assembly of graphene oxide on chitosan matrix and its application in removal of different heavy metal ions from wastewater was investigated. The synthesized xerogel was characterized through FTIR, SEM, XRD and BET surface area analysis. Heavy metal ions, including Pb(II), Cd(II), and Hg(II), were removed from wastewater using this graphene-chitosan (GO-Cs) xerogel and the removal efficiency was monitored through inductively coupled plasma mass spectrometry (ICP-MS). The effect of GO-Cs composition and pH on adsorption efficiency as well as the kinetics of adsorption was studied in detail. The study exhibited that this xerogel… More >

N. Selvakumar^1,2, Uday Pradhan¹, S.B. Krupanidhi², Harish C. Barshilia^1,*

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 175-185, 2016, DOI:10.3970/cmc.2016.052.173

Abstract Graphene oxide was synthesized from graphite flakes using modified Hummers’ method. The interlayer spacings of graphite, graphite oxide and graphene oxide were measured using X-ray diffraction technique. The C/O atomic ratios of graphite oxide and graphene oxide were calculated from XPS measurements. The transformation of graphite to graphite oxide and finally to graphene oxide was clearly observed from the micro-Raman spectroscopy data and was confirmed from the FESEM micrographs. UV-VIS-NIR spectrophotometer was used to study the absorbance of graphene oxide and reduced graphene oxide samples. Finally, the chemically reduced graphene oxide was heat-treated in air to obtain chemically modified graphene. More >

Anusha Eldo¹, Balamati Choudhury²

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 143-157, 2016, DOI:10.3970/cmc.2016.052.142

Abstract The advances in metamaterial science and technology have raised the expectations of camouflage or stealth researchers to one order higher in terms of absorption characteristics. As metamaterial inspired radar absorbing structures are proving themselves as a good candidate with near unity absorption, feasibility towards hardware realization is necessary. Hence an extensive literature survey of metamaterial inspired radar absorbing structure has been carried out and reported in this paper along with the challenges and material issues. The various types of metamaterial structures that can be used as absorber have been provided along with simulation figures. To make the review more useful,… More >

Taeshik Yoon^1,†, Sumin Kang^1,†, Tae Yeob Kang¹, Taek-Soo Kim^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 351-361, 2019, DOI:10.32604/cmes.2019.06672

Abstract Detection of cracks is a great concern in production and operation processes of graphene based devices to ensure uniform quality. Here, we show a detection method for graphene cracks by electromagnetic induction. The time varying magnetic field leads to induced voltage signals on graphene, and the signals are detected by a voltmeter. The measured level of induced voltage is correlated with the number of cracks in graphene positively. The correlation is attributed to the increasing inductive characteristic of defective graphene, and it is verified by electromagnetic simulation and radio frequency analysis. Furthermore, we demonstrate that the induced voltage signal is… More >

Kentaro Doi^1,2, Ikumi Onishi¹, Satoyuki Kawano^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.2, pp. 113-136, 2011, DOI:10.3970/cmes.2011.077.113

Abstract Hydrogen technologies are currently one of the most actively researched topics. A lot of researches have tied to enhance their energy conversion efficiencies. In the present study, numerical analyses have been carried out focusing on hydrogen-storage carbon materials which are expected to realize high gravimetric and volumetric capacities. In particular, dissociative adsorption processes of H₂ molecules above graphene surfaces have been investigated by ab initio molecular dynamics. The present results indicate that a steric graphene surface plays an important role in enhancing the charge transfer which induces dissociation of H₂ and adsorption of H atoms on the surface. The dissociation… More >

G. Shi ¹, P. Zhao ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.71, No.1, pp. 67-92, 2011, DOI:10.3970/cmes.2011.071.067

Abstract Based on molecular mechanics and the concept of flexible connection used in the flexibly connected frames, a new structural mechanics model, a 2-D frame composed of anisotropic beams and flexible connections, is proposed for the simulation of the static and dynamic flexural behavior of monolayer graphene. The equivalent beam representing the C-C bond in the new molecular structural mechanics (MSM) model has two salient features compared with other MSM models presented for the analysis of carbon nanotubes: one is that the flexible connections at the beam ends are used to account for the bond-angle variations between the C-C bonds of… More >

Y. Inoue¹, R. Kobayashi¹, S. Ogata¹, T. Gotoh¹

CMES-Computer Modeling in Engineering & Sciences, Vol.63, No.2, pp. 137-162, 2010, DOI:10.3970/cmes.2010.063.137

Abstract Vibration of a single graphene and a pair of graphenes at micro meter scale induced by air flow is numerically simulated and examined by using a hybrid computational method starting from a microscopic level of description for the graphene. In order to bridge a huge gap in spatial and time scales in their motions, the carbon atoms of the graphene are represented by a small number of coarse grained particles, the fluid motion is described by the lattice Boltzmann equation and the momentum exchange at the boundary is treated by the time averaged immersed boundary method. It is found that… More >

L.S. Melro^1,2, L.R. Jensen¹

CMC-Computers, Materials & Continua, Vol.53, No.2, pp. 109-127, 2017, DOI:10.3970/cmc.2017.053.111

Abstract Molecular dynamics simulations were applied in order to calculate the Young’s modulus of graphene functionalized with carboxyl, hydroxyl, carbonyl, hydrogen, methyl, and ethyl groups. The influence of the grafting density with percentages of 3, 5, 7, and 10% and the type of distribution as a single cluster or several small clusters were also studied. The results show that the elastic modulus is dependent on the type of functional groups. The increasing coverage density also evidenced a decrease of the Young’s modulus, and the organization of functional groups as single cluster showed a lesser impact than for several small clusters. Furthermore,… More >

Chih-Ping Wu^1,2, Wei-Chen Li¹

CMC-Computers, Materials & Continua, Vol.52, No.2, pp. 73-103, 2016, DOI:10.3970/cmc.2016.052.073

Abstract A three-dimensional (3D) asymptotic theory is reformulated for the static analysis of simply-supported, isotropic and orthotropic single-layered nanoplates and graphene sheets (GSs), in which Eringen's nonlocal elasticity theory is used to capture the small length scale effect on the static behaviors of these. The perturbation method is used to expand the 3D nonlocal elasticity problems as a series of two-dimensional (2D) nonlocal plate problems, the governing equations of which for various order problems retain the same differential operators as those of the nonlocal classical plate theory (CST), although with different nonhomogeneous terms. Expanding the primary field variables of each order… More >

G. Q. Xie¹, J. P. Wang², Q. L. Zhang¹

CMC-Computers, Materials & Continua, Vol.48, No.2, pp. 103-117, 2015, DOI:10.3970/cmc.2015.048.103

Abstract Small-scale effect on the static deflection of a clamped graphene sheet and influence of the helical angle of the clamped graphene sheet on its static deflection are investigated. Static equilibrium equations of the graphene sheet are formulated based on the concept of nonlocal elastic theory. Galerkin method is used to obtain the classical and the nonlocal static deflection from Static equilibrium equations , respectively. The numerical results show that the static deflection and small-scale effect of a clamped graphene sheet is affected by its small size and helical angle. Small-scale effect will decrease with increase of the length and width… More >