Correlation of Fabrication and Structural/Electronic Properties of Carbon Nanotubes Using TEM/EELS

2000 ◽  
Vol 6 (S2) ◽  
pp. 204-205
Author(s):  
B. W. Reed ◽  
M. Sarikaya ◽  
L. R. Dalton ◽  
G. F. Bertsch

Since their discovery, carbon nanotubes have been the focus of much research effort aimed at optimizing growth conditions, elucidating physical structure, and measuring electronic properties. Measurement methods have included high resolution techniques such as AFM, STM, TEM, and EELS, as well as surface and bulk spectroscopic techniques, such as XPS. Most investigations have been quite specific, centering on a small number of nanotubes formed under particular growth conditions and typically employing only one or two modes of analysis. Broader, more systematic studies are relatively rare, and it is the intent of the present work to help fill this gap. We combine results of high-resolution TEM imaging, electron diffraction, low-energy EELS, and carbon K-edge EELS to characterize a variety of nanotube samples, grown and annealed under various conditions.The Carbon Nanotubes (Cnts) Are Made By The Dual, Pulsed-Laser Vaporization Method, And Purified With A Process That Involves Nitric Acid Reflux, Washing/Centrifugation Cycles, Hollow-Fiber, And Cross-Flow Filtration.

2011 ◽  
Vol 1284 ◽  
Author(s):  
Shigekazu Ohmori ◽  
Takeshi Saito ◽  
Bikau Shukla ◽  
Motoo Yumura ◽  
Sumio Iijima

ABSTRACTWe report a novel system for sorting single wall carbon nanotubes (SWCNTs) by length via cross-flow filtration with three membrane filters of different pore sizes, 1.0, 0.45, and 0.2 μm. SWCNTs dispersed in water with the help of polymer type detergents, such as sodium carboxymethylcellulose (CMC) and polyoxyethylene stearyl ether (Brij 700), were successfully fractionated into four samples, and the atomic force microscopy (AFM) observation of those samples confirmed that their length distribution peaks are within the expected ranges from pore sizes of used filters. However, the result of the similar filtration process using a non-polymer detergent, sodium dodecylbenzenesulfonate (SDBS), showed no pronounced correlation between the length distribution of SWCNTs and the pore size. The observed difference in the sorting phenomena caused by the detergent type suggests that the permeation property depends on the complex structure resulting from the dispersed SWCNTs and detergent molecules.


ACS Nano ◽  
2010 ◽  
Vol 4 (7) ◽  
pp. 3606-3610 ◽  
Author(s):  
Shigekazu Ohmori ◽  
Takeshi Saito ◽  
Bikau Shukla ◽  
Motoo Yumura ◽  
Sumio Iijima

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 411
Author(s):  
Irena Zizovic ◽  
Marcin Tyrka ◽  
Konrad Matyja ◽  
Ivana Moric ◽  
Lidija Senerovic ◽  
...  

This study investigates the modification of commercial cellulose acetate microfiltration membranes by supercritical solvent impregnation with thymol to provide them with antibacterial properties. The impregnation process was conducted in a batch mode, and the effect of pressure and processing time on thymol loading was followed. The impact of the modification on the membrane’s microstructure was analyzed using scanning electron and ion-beam microscopy, and membranes’ functionality was tested in a cross-flow filtration system. The antibiofilm properties of the obtained materials were studied against Staphyloccocus aureus and Pseudomonas aeruginosa, while membranes’ blocking in contact with bacteria was examined for S. aureus and Escherichia coli. The results revealed a fast impregnation process with high thymol loadings achievable after just 0.5 h at 15 MPa and 20 MPa. The presence of 20% of thymol provided strong antibiofilm properties against the tested strains without affecting the membrane’s functionality. The study showed that these strong antibacterial properties could be implemented to the commercial membranes’ defined polymeric structure in a short and environmentally friendly process.


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