CARBON NANOTUBE REINFORCED METAL COMPOSITES

A carbon nanotube reinforced metal nanocomposite material includes a continuous metal phase, and a pluarlity of carbon nanotubes dispersed in the continuous metal phase. The metal phase extends throughout substantially an entire thickness of the nanocomposite material. The nanotubes are preferably single wall nanotubes (SWNTs). Carbon nanortube reinforced metal nanocomposites according to the invention provide thermal conductivity and electrical conductivity which are generally significantly higher than the pure metal continuous phase material, mechanical strength is 2 to 3 times greater than that of pure metal, and a tailorable coefficient of thermal expansion obtainable through changing the percentage of nanotubes in the nanocomposite

Electrochemical-Codeposition Methods for Forming Carbon Nanotube Reinforced Metal Composites - CIP

An electrochemical-codeposition method for forming a carbon nanotube (CNT) reinforced metal nanocomposite includes providing a reaction vessel having an anode and a cathode and a plating solution therein, where the plating solution includes at least one acid, at least one surfactant, a plurality of CNTs, and plurality of metal cations that includes at least one metal. The plating solutaion has a pH between 2 and 4.5 and at least one portion of the plurality of CNTs are positively charged CNTs in the plating solution. A power supply is connected between the anode and the cathode. The positively charge CNTs and the metal cations are both electrochemically-codepositioned onto the cathode to form the nanocomposite, wherein the metal provides a continuous metal phase for the nanocomposite

Fabrication and characterization of crystalline copper nanowires by electrochemical deposition inside anodic alumina template

Copper nanowires were fabricated by electrochemical deposition inside anodic alumina template anodized on aluminum substrate. The morphology, composition and structure of the copper nanowires were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive (EDS) and X-ray diffraction spectroscopy (XRD). The results revealed that copper nanowires were dense, continuous, highly-crystalline and uniform with diameters. The electrical properties of copper nanowires wrer characterized with two-terminal electrical measurements. Different current-voltage (I-V) characteristics of single copper nanowire were observed and possible conductive mechanisms were discussed. The crystalline copper nanowires are promising in application of future nanoelectronic devices and circuits. © 2013 The Author(s)

Characterization study of bonded and unbonded polydimethylsiloxane aimed for bio-micro-electromechanical systems-related applications

Authors have demonstrated that by controlling the mixing ratio of polydimethylsiloxane\u27s (PDMS\u27s) two components-base polymer (part A) and a curing agent (part B)-different mechanical properties of PDMS can be achieved. Test results show that the Young\u27s modulus decreases as the increasing of mixing ratios (A: B). However, there is a transitional mixing ratio (part A:part B=10) after which the Young\u27s modulus is almost independent of the mixing ratio. The PDMS\u27s thickness plays an important role in determining the mechanical properties. The results show that the thinner the PDMS, the stiffer it behaves. The bonding strength between two cured PDMS parts with different mixing ratios shows that it depends on the mixing ratio. A maximum bonding strength of 130 kPa occurs on a bonded couple with mixing ratios of 30A: 1 B and 3A: 1 B, respectively. The fracture on bonded specimens does not occur at the bonding interfaces. Instead it occurs at the side with a larger portion of part A. The intermediate material property formed at the interface is attributed to the diffusion layer formed. (c) 2007 Society of Photo-Optical Instrumentation Engineers

Fabrication of one-dimensional Ag/multiwalled carbon nanotube nano-composite

Composite made of multiwalled carbon nanotubes coated with silver was fabricated by an electroless deposition process. The thickness of silver layer is about 40 to 60 nm, characterized as nano-crystalline with (111) crystal orientation along the nanotube's axial direction. The characterization of silver/carbon nanotube [Ag/CNT] nanowire has shown the large current carrying capability, and the electric conductivity is similar to the pure silver nanowires that Ag/CNT would be promising as building blocks for integrated circuits

Development Of Self-Assembled Robust Microvalves With Electroform Fabricated Nano-Structured Nickel

Self-assembled robust micro check valves with large flow rates (\u3e10 cc/second, displacement related), high-pressure support ability (\u3e10 MPa) and high operational frequencies (\u3e10 kHz) made of nano-structured nickel were presented in this paper. The microvalve consists of an array of 80 single micro valves to achieve the required flow rates. A novel in situ UV-LIGA process was developed for the fabrication. Self-assembling was realized by guiding the electroforming process during the fabrication process. Test results show that the forward flow rate is about 19 cc/second under pressure of 90Psi. The backward flow rate is negligible. The reliability of the valve was tested by a specific loading/unloading sequence. Results show that the flow rates were repeated very well over a large range of tested pressure differences

Sol-Gel Prepared Single Wall Carbon Nanotube Sno2 Thin Film For Micromachined Gas Sensor

We report here a novel micromachined single wall carbon nanotube (SWNT)/tin dioxide (SnO2) nano film gas sensor. A polymeric sol-gel process in combination with purified SWNT has been successfully developed in fabricating SWNT/SnO2 thin film nanocomposite sensor on an alumina substrate. The test of the novel nanocomposite gas sensors has been conducted for hydrogen detection, in comparison with sol gel derived SnO2 thin film. The test results show that SWNT has greatly improved the nano-SnO2 thin film\u27s gas sensing property, in terms of lower working temperature, greater sensitivity (a factor of 3), faster response time and recovery time, and less drift of resistance. The improved capabilities are credited to the large surface to volume ratio of gas sensing thin film with nano passes created by SWNT, and the distance between adjacent passages being less than electron depletion layer thickness is defined by SWNT. The fabrication process is compatible with IC industry thus it is cost effective for batch production

Electronic Structure And Transport Properties Of Carbon Nanotube Adsorbed With A Copper Chain

The authors have studied the electronic structure and transport properties of hybrid nanowires made of a copper chain adsorbed on a single-wall carbon nanotube (CNT) using first principle methods. Results have shown that after the adsorption of the Cu chain, the density of states and the transmission coefficients of the CNT (5, 5)/Cu nanowire have been increased, while the band gap of CNT (10, 0)/Cu have been significantly reduced. These results imply that the conductivity of CNTs, either metallic or semiconducting, have been enhanced by the adsorption of a copper chain. These hybrid nanowires with enhanced conductivity may be suitable for nanoelectronics. © 2013 The Author(s). Published by Taylor & Francis

The Electric Resistance And The Transport Properties Of Carbon Nanotube With A Cu Chain: A First-Principle Study

The electric resistance and the transport properties of a carbon nanotube (5, 5) adsorbed with a copper chain connected with two copper end electrodes have been calculated by employing the nonequilibrium Green\u27s function and the Density Function Theory. The properties of the pure carbon nanotube (5,5) with the Cu electrodes have also been calculated as a reference. Both the equilibrium and the nonequilibrium conditions have been investigated, The results have shown that the electrical resistance of the metallic CNT (5,5) has been reduced by the adsorption of the Cu chain due to the interaction between the Cu and the CNT. The change of the 1-V curve slope is also explained in terms of the transmission spectrum. © 2013 Materials Research Society

Ultrasonic-Assisted Fabrication Of Highly Dispersed Copper/Multi-Walled Carbon Nanotube Nanowires

Highly dispersed copper/multi-walled carbon nanotube (MWCNT) nanowires have been fabricated using ultrasonic-assisted electroless copper plating. The structures of the Cu/MWCNT nanowires were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). The study clearly demonstrates the advantages of the ultrasonic technique on electroless copper plating on MWCNT, including an enhanced electroless copper deposition rate, improved interfacial bonding as well as preventing Cu/MWCNT nanowires from aggregating. © 2009 Elsevier B.V. All rights reserved