Jan Badorrek^1,2, Michael Walter^3,4,*, Marie-Pierre Laborie^1,2,*

Journal of Renewable Materials, Vol.6, No.3, pp. 325-335, 2018, DOI:10.7569/JRM.2017.634183

Abstract Doping lignin with carbon nanotubes is a promising strategy for cost-effective high-performance carbon fibers. We investigate the intermolecular interaction potential of CNT and organosolv lignin with two main approaches. Experimentally, oxidized purified multiwalled carbon nanotubes (MWCNTs) and beech organosolv lignins and derivatives are analyzed with their Hansen solubility parameters (HSPs) to assess their mutual compatibility. Theoretically, dispersion-corrected density functional theory simulations of the interaction between model molecules and single-walled carbon nanotubes reveal the source of interactions. We find that oxidation enables and enhances the interaction between carbon nanotubes and organosolv lignin experimentally, which is in More >

Rajendran Muthuraj, Abhishek Sachan, Mickael Castro*, Jean-François Feller, Bastien Seantier*, Yves Grohens

Journal of Renewable Materials, Vol.6, No.3, pp. 277-287, 2018, DOI:10.7569/JRM.2017.634182

Abstract In this work, thermally insulating and electrically conductive aerogels were prepared from cellulose nanofibers (CNF) and carbon nanotubes (CNTs) by environmentally friendly freeze-drying process. The thermal conductivity of neat CNF aerogel is 24 mW/(m·K) with a density of 0.025 g/cm3. With the addition of CNTs into CNF aerogel, the electrical conductivity was significantly increased while the thermal conductivity was increased to 38 mW/(m·K). Due to these interesting properties, the Seebeck coefficient and the figure of merit (ZT) of the CNF/CNTs aerogels were measured and showed that CNF/CNTs aerogel thermoelectric properties can be improved. The compressibility More >

Mahantesh M Nandeppanavar^a,*, S. Shakunthala^b

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-10, 2017, DOI:10.5098/hmt.9.27

Abstract In this paper, the buoyancy effect on flow and heat transfer characteristics of nanofluid in presence of carbon nanotubes due to a vertical plate is investigated. The obtained nonlinear PDE’s are converted to the non-linear ordinary differential equations by applying the similarity transformations corresponding to the boundary conditions. These boundary value problems are solved numerically using fourth order Runge-kutta method together with the efficient shooting iteration scheme. The nature of the flow and heat transfer are plotted and discussed in detail. It is noticed that buoyancy effect is very useful in cooling the system and More >

A. Delgado-Lima, M. C. Paiva^*, A. V. Machado

Journal of Renewable Materials, Vol.5, No.2, pp. 145-153, 2017, DOI:10.7569/JRM.2017.634104

Abstract Cellulose acetate (CA) is produced from a natural polymer and presents excellent properties, finding applications in a variety of areas. Unlike cellulose, CA is melt processable and may be molded into parts and formed into fibers or films. In this context, the production of conductive CA composites that may be processable and integrated into parts to provide specific functionalities is an area of increasing interest. The present work aims to prepare electrically conductive composites based on CA and carbon nanotubes (CNTs) by melt mixing. The nanocomposites were produced with pure and pyrrolidine-functionalized nanotubes, using a More >

Salvatore Brischetto¹

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.4, pp. 305-327, 2015, DOI:10.3970/cmes.2015.104.305

Abstract This paper proposes the free vibration analysis of Double-Walled Carbon NanoTubes (DWCNTs). A continuum elastic three-dimensional shell model is used for natural frequency investigation of simply supported DWCNTs. The 3D shell method is compared with beam analyses to show the applicability limits of 1D beam models. The effect of van der Waals interaction between the two cylinders is shown for different Carbon NanoTube (CNT) lengths and vibration modes. Results give the van der Waals interaction effect in terms of frequency values. In order to apply the 3D shell continuum model, DWCNTs are defined as two More >

Qing Song Tu¹, Michelle Lee², Samuel Zhang², Shaofan Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.3, pp. 247-259, 2014, DOI:10.32604/cmes.2014.098.247

Abstract In this paper, we present molecular dynamics simulations of diffusion of Na⁺, K⁺, and Cl^- ions through the single-walled carbon nanotubes(SWCNTs) that are embedded into the membrane of cells in aqueous solutions. A simplified atomic cell model that considers bilayer membranes is employed to study the transportation of ions inside CNTs. The simulated results indicate that the diffusion properties of ions and selectivity of CNT with respect to ions are affected by biological complexity of the cell membrane. We have found that the ion diffusion only occurs in the CNTs with chirality higher than (8, 8), which More >

Chih-Ping Wu^1,2, Ruei-Yong Jiang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.3, pp. 239-279, 2014, DOI:10.3970/cmes.2014.097.239

Abstract A state space differential reproducing kernel (DRK) method is developed for the three-dimensional (3D) buckling analysis of simply-supported, carbon nanotube-reinforced composite (CNTRC) circular hollow cylinders and laminated composite ones under axial compression. The single-walled carbon nanotubes (CNTs) and polymer are used as the reinforcements and matrix, respectively, to constitute the CNTRC cylinder. Three different distributions of CNTs varying in the thickness direction are considered (i.e., the uniform distribution and functionally graded rhombus-, and X-type ones), and the through-thickness distributions of effective material properties of the cylinder are determined using the rule of mixtures. The 3D… More >

Soleiman Ghouhestani¹, Farzad Shahabian¹, Seyed Mahmoud Hosseini^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.4, pp. 295-321, 2014, DOI:10.3970/cmes.2014.100.295

Abstract In this paper, the meshless local Petrov-Galerkin (MLPG) method is exploited for dynamic analysis of functionally graded nanocomposite cylindrical layered structure reinforced by carbon nanotube subjected to mechanical shock loading. The carbon nanotubes (CNTs) are distributed across radial direction on thickness of cylinder, which can be simulated by linear and nonlinear volume fraction. Free vibration and elastic wave propagation are studied for various value of volume fraction exponent at various time intervals. The layered cylinder is assumed to be under axisymmetric and plane strain conditions. Four types of CNTs distributions including uniform and three kinds… More >

J. Joseph¹, Y. C. Lu ¹,

CMC-Computers, Materials & Continua, Vol.42, No.1, pp. 63-74, 2014, DOI:10.3970/cmc.2014.042.063

Abstract The super-long, vertically aligned carbon nanotubes (SL-VACNTs) are novel carbon nanomaterial produced from template-free synthesis. The mechanical responses of such material have been investigated by continuum finite element modeling and compared with experimental observations. The crushable foam model has been adequate in modeling the stress-strain curve and deformation of the SL-VACNTs under compression. SL-VACNTs are seen to exhibit transient elastic deformation at small displacement and then plastic deformation at large displacement. The deformation mostly occur at the position immediately beneath the compression platen (indenter face) due to the high stress/strain concentrations. More >

Anna Y. Matveeva¹, Helmut J. Böhm², Grygoriy Kravchenko², Ferrie W. J. van Hattum¹

CMC-Computers, Materials & Continua, Vol.42, No.1, pp. 1-23, 2014, DOI:10.3970/cmc.2014.042.001

Abstract This paper presents a comparison of different finite element approaches to modelling polymers reinforced with wavy, hollow fibres with the aim of predicting the effective elastic stiffness tensors of the composites. The waviness of the tubes is described by sinusoidal models with different amplitude-to-wavelength parameters. These volume elements are discretized by structured volume meshes onto which fibres in the form of independently meshed beam, shell or volume elements are superimposed. An embedded element technique is used to link the two sets of meshes. Reference solutions are obtained from conventional three-dimensional volume models of the same More >