Publication Date:
2003-12-03
Description:
An array of aligned carbon nanotubes (CNTs) was incorporated across a polymer film to form a well-ordered nanoporous membrane structure. This membrane structure was confirmed by electron microscopy, anisotropic electrical conductivity, gas flow, and ionic transport studies. The measured nitrogen permeance was consistent with the flux calculated by Knudsen diffusion through nanometer-scale tubes of the observed microstructure. Data on Ru(NH3)6(3+) transport across the membrane in aqueous solution also indicated transport through aligned CNT cores of the observed microstructure. The lengths of the nanotubes within the polymer film were reduced by selective electrochemical oxidation, allowing for tunable pore lengths. Oxidative trimming processes resulted in carboxylate end groups that were readily functionalized at the entrance to each CNT inner core. Membranes with CNT tips that were functionalized with biotin showed a reduction in Ru(NH3)6(3+) flux by a factor of 15 when bound with streptavidin, thereby demonstrating the ability to gate molecular transport through CNT cores for potential applications in chemical separations and sensing.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hinds, Bruce J -- Chopra, Nitin -- Rantell, Terry -- Andrews, Rodney -- Gavalas, Vasilis -- Bachas, Leonidas G -- New York, N.Y. -- Science. 2004 Jan 2;303(5654):62-5. Epub 2003 Nov 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemical and Materials Engineering, University of Kentucky, Lexington KY 40506, USA. bjhinds@engr.uky.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14645855" target="_blank"〉PubMed〈/a〉
Keywords:
Biotin/chemistry
;
Diffusion
;
Electric Conductivity
;
Electrochemistry
;
Ions/chemistry
;
*Membranes, Artificial
;
Microscopy, Electron
;
Microscopy, Electron, Scanning
;
*Nanotubes, Carbon
;
Nitrogen/chemistry
;
Oxidation-Reduction
;
Polymers
;
Ruthenium Compounds/chemistry
;
Streptavidin/chemistry
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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