Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Carbon Nanotubes

Effect of Carbon Nanotube on Damping Characteristic of Epoxy Polysulfide Blend Composite

Adnan Neama Abood; Ibtihal. A. Mahmood; Ekhlas Edan Kader

Engineering and Technology Journal, 2016, Volume 34, Issue 1, Pages 73-84

In a Nano-composite structure, it is anticipated that high damping can be achieved by taking advantage of the interfacial friction between the nanotubes and the polymer. The purpose of this paper is to investigate the structural damping characteristics of polymeric composites containing Carbon nanotubes (CNTs) with various amounts with polysulfide rubber (PSR) . The damping characteristics of the specimens with 0 wt% and 0.6 wt% Carbon nanotube contents were computed experimentally. Through comparing with neat resin specimens (epoxy, epoxy +PSR), the study showed that one can enhance damping by adding CNTs fillers into polymeric resins. Similarly experiment showed that the maximum value of damping ratio was obtained at 0.4 wt% CNTs.

Theoretical Description for Zitterbewegung of electrons in SWCNT (Single Wall Carbon Nanotubes)

M. J. Majid; S. S. Savinskii

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 779-790

The problem of the time evolution of localized quantum states for electrons in the semiconducting and metallic single wall carbon nanotubes (SWCNT) are studied analytically and numerically. In the long-wave approximation , where a is the interatomic distance of carbon atoms in the graphene lattice, the carrier wave vector of the wave packet, we consider the time evolution of localized quantum states by using a model Hamiltonian. The localized quantum states are interpreted as a superposition of the valence band and the conduction band. The dynamic of the wave packet which is represented by localized quantum states in carbon nanotubes was considered with cylindrical symmetry. The time dependent average values of the angular and axial coordinate operators and its oscillations behavior are calculated. In addition, we taken into account the effect of an external magnetic field which is applied along the axis of carbon nanotube. The evaluations of the frequency and amplitude of zitterbewegung in the carbon nanotube are presented, which can be used for the experimental prospective studies in the nanoelectronic applications.
Heisenberg representation in the present study are used to evaluate the average values of the coordinate operators , furthermore , Schrödinger representation are used for interpreting the results of the trembling motion (Zitterbewegung) in the carbon nanotubes.

Synthesis of TiO2/Pd/Multi-Walled Carbon Nano-Structures by Hydrothermal Technique and deposited it on n-Si substrate as TiO2/Pd/MWCNTs:n-Si Heterojunction by Pulsed Laser Deposition

Saif M. Alshrefi; Dunia K. Mahdi; Zainab S.Sadik

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 867-883

Carbon nanostructures (CNTs) have been prepared by a Hydrothermal deposition technique based on the polymer Polyethylene glycol (PEG) dissolved in water and Ethanol alcohol of a new carbon sources materials mixed with (PdCl2) as a catalyst mixed with Sodium hydroxide (8gm NaOH) using Parr reactor at temperature (190°C) and forming the hybrid composite material (TiO2/Pd/MWCNTs) by the same way. Thence, deposited heterojunction material (TiO2/Pd/MWCNTs:n-Si) using the Pulsed Laser Deposition Technique (PLD), on the substrate of n-silicon wafer. The obtained (MWCNTs & TiO2/Pd/MWCNTs) are investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray Photo-electron Spectroscopy (XPS). Normal MWCNTs are formed multi-walled carbon nanotubes (MWCNTs) and carbon nanosheets (CNSs) but in little bit amount. MWCNTs were obtained as main products with lengths of (1.6–3 μm) and diameters of (30-60 nm) could be synthesized at as low temperature as (190°C). Deconvolution of the (C1s ) peaks which characteristic of C-C bonds, showed a main peak at (284.96 and 285.04 eV) with total amount (74.96 and 30.64 at%) for the product of MWCNTs and TiO2/Pd/MWCNTs composite respectively. Current – voltage characteristics of heterojunction showed that forward bias current change exponentially approximately with applied voltage at dark and this agreement with tunneling–recombination model. Also (I-V) characteristics under illumination of TiO2/Pd/MWCNTs heterojunction deposited on p-Si substrate (η=10.5) efficiency in Solar Cell.

Surface Modification of Multiwall Carbon Nanotubes for Metal Matrix Nan composite Applications

Ahmed Ali Moosa; Abdul Qader Faisal; Righdan Mohsen Namus

Engineering and Technology Journal, 2014, Volume 32, Issue 7, Pages 1859-1869

MWCNTs first functionalized by using two steps covalent functionalization process. Functionalized MWCNTs coated with copper by using electroless coating process. Three different groups of Cu/MWCNTs nanocomposites with (0.1, 0.5, 1, 2, 3 wt% MWCNTs) were prepared by means of powder technology. The first group contains multiwalled carbon nanotubes as received (Cu/MWCNTs), second group contains functionalized multiwalled carbon nanotubes (Cu/FMWCNTs) while the third group contains coated multiwalled carbon nanotubes (Cu/CMWCNTs). Comparison between these samples show that the coating of MWCNTs was remarkably improve hardness and wear resistance of copper nanocomposite. The improvement in mechanical properties is due to the enhancement in both adhesion with matrix and dispersion ability of MWCNTs. SEM, XRD, FTIR were used to characterize of coating process and Cu/MWCNTs nanocomposites.

Synthesis of Carbon Nanomaterials in Deionized Water with and without Catalyst Using Arc Discharge Technique

Abdul Qader D. Faisal; Mufeed A. Jaleel; Aysar S. Keiteb

Engineering and Technology Journal, 2011, Volume 29, Issue 2, Pages 240-252

Simple and economical technique was used for synthesis of carbon
nanomaterials without using vacuum equipment. The used technique implied an
arc discharge between two pure graphite rods with different diameters submerged
in deionized water at room temperature. These were also investigated with a new
type of metal catalyst process for the first time. Plasma arc discharge was
produced using D.C power supply with current (30-90 amp.) and voltage (30-
50volt). The nanomaterials were produced in the form of nanoparticles (floated),
nanotubes and nanofibers (sank), and carbon nanocolloidal (dispersed) through the
water. The results of these experiments were examined by high resolution optical
microscope, scanning electron microscope SEM and transmission electron
microscope TEM. The results revealed different types of carbon nanomaterials.