Chi Huynh

Recent Developments in Carbon Nanotube Membranes for Water Purification and Gas Separation

Carbon nanotubes (CNTs) are nanoscale cylinders of graphene with exceptional properties such as high mechanical strength, high aspect ratio and large specific surface area. To exploit these properties for membranes, macroscopic structures need to be designed with controlled porosity and pore size. This manuscript reviews recent progress on two such structures: (i) CNT Bucky-papers, a non-woven, paper like structure of randomly entangled CNTs, and (ii) isoporous CNT membranes, where the hollow CNT interior acts as a membrane pore. The construction of these two types of membranes will be discussed, characterization and permeance results compared, and some promising applications presented.

Carbon Nanotube Webs: A Novel Material for Sensor Applications

Since their discovery in 1991 by Iijima, [ 1 ] carbon nanotubes (CNTs) have attracted intensive research and investigation due to their unique electrical, mechanical, structural, and chemical properties. [ 2 , 3 ] Their novel properties make them attractive for fabricating electrochemical sensors and biosensors. Several compounds have been reported to undergo improved electrochemical reactions at the CNT surface, such as cytochrome c, [ 4 ]

Aligned silane-treated MWCNT/liquid crystal polymer films

We report on a method to preferentially align multiwall carbon nanotubes (MWCNTs) in a liquid crystalline matrix to form stable composite thin films. The liquid crystalline monomeric chains can be crosslinked to form acrylate bridges, thereby retaining the nanotube alignment. Further post-treatment by ozone etching of the composite films leads to an increase in bulk conductivity, leading to higher emission currents when examined under conducting scanning probe microscopy. The described methodology may facilitate device manufacture where electron emission from nanosized tips is important in the creation of new display devices.

Enhanced mechanical performance of CNT/Polymer composite yarns by γ -irradiation

Multiwall carbon nanotube (CNT) spun yarns were subjected to γ-irradiation in an oxygen rich environment, followed by the application of epoxy to form CNT/epoxy composite yarns with a high CNT fraction. The method for fabrication of the CNT/polymer composite yarns was presented, and the effect of γ-irradiation on the mechanical performance of the pure CNT spun yarns and their epoxy composite yarns were studied. The γ-irradiated CNT yarns were also characterized by X-ray Photoelectron Spectroscopy and Raman spectroscopy. The results of this study have demonstrated that the γ-irradiation is an effective micro-engineering tool to improve mechanical properties of the CNT spun yarn and its epoxy composite yarn.

Dry Drawn Multiwall Carbon Nanotube Sheet as a Counter Electrode for Dye-Sensitized Solar Cells: Multilayer Optimization

We demonstrate the fabrication of dye sensitized solar cells using multiwall carbon nanotube (MWNT) sheets as a counter electrode with catalytic activity optimized by layering as an alternative to platinum deposited on fluorinated tin oxide (FTO). The sheets are drawn directly from a highly aligned forest of MWNTs grown on silicon by chemical vapor deposition. We used different number of MWNT layers on the FTO and pure glass. Cell performance was found to vary with the number of MWNT sheets. When using of 10 or more layers we can substitute the FTO with platinum catalytic particles.

Impact of Carbon Nanotube Aspect Ratio and Dispersion on Epoxy Nanocomposite Performance

This paper compared the effect of aspect ratios and dispersions of carbon nanotubes (CNT) made in CSIRO, with a broad range of aspect ratios with similar dimensions in diameter, on the electric conductivity, rheology and dynamic mechanical thermal analysis of multi-wall nanotubes (MWNT)/epoxy nanocomposites. A medium aspect ratio seems to be the most effective in conductive network formation in epoxy matrix and also provide best storage modulus of CNT/epoxy nanocomposites under providing processing conditions.