{"id":648,"date":"2014-04-09T20:12:10","date_gmt":"2014-04-09T20:12:10","guid":{"rendered":"https:\/\/techfragments.com\/?p=648"},"modified":"2022-08-03T20:27:20","modified_gmt":"2022-08-03T20:27:20","slug":"nanotube-graphene-hybrid-easier-handling","status":"publish","type":"post","link":"https:\/\/techfragments.com\/nanotube-graphene-hybrid-easier-handling\/","title":{"rendered":"New Nanotube Graphene Hybrid Material Easier To Handle"},"content":{"rendered":"

Reinforcing bars of carbon nanotubes<\/a> make two-dimensional graphene much easier to handle, researchers at Rice University have found.<\/p>\n

The new hybrid, according to Rice chemist James Tour, could, when stacked in a few layers, make a cost-effective alternative for costly indium tin oxide<\/a> (ITO). ITO is currently used in displays and solar cells.<\/p>\n

Tour set nanotubes into graphene in a way that is analogous to how steel rebar is used in concrete. This method also conserves and even improves both materials\u2019 electrical and mechanical qualities.<\/p>\n

The finding is significant because it should make large, flexible, conductive and transparent sheets of graphene much easier to manipulate, which should be of interest to electronics manufacturers, Tour said.<\/p>\n

Re-bar Graphene Benefits<\/h2>\n
\"hybrid

Carbon nanotubes that serve as reinforcing bars in graphene partially unzip in the process. The unzipped part bonds covalently with the graphene sheet, providing an uninterrupted electrical connection. Credit: Tour Group<\/p><\/div>\n

A single-layer matrix of carbon atoms, graphene is one of the strongest materials on the planet. Nevertheless, it can be quite the challenge to lift the tiny sheets from the catalyst substrate they are grown on, typically by chemical vapor deposition, Tour said.<\/p>\n

\u201cNormally you grow graphene on a metal, but you can\u2019t just dissolve away the metal,\u201d Tour said. \u201cYou put a polymer on top of the graphene to reinforce it, and then dissolve the metal. Then you have polymer stuck to the graphene. When you dissolve the polymer, you\u2019re left with residues, and these trace impurities limit graphene\u2019s effectiveness for high-speed electronics and biological devices. By taking away the polymer support step, we greatly expand the potential for this material.\u201d<\/p><\/blockquote>\n

To fabricate what they are calling rebar graphene, the researchers just spin-coat and then heat and cool functionalized single- or multiwalled carbon nanotubes on copper foils, using the nanotubes themselves as the carbon source.<\/p>\n

When heated, the functional carbon groups decompose and form graphene, while the nanotubes partially split and form covalent junctions with the new graphene layer.<\/p>\n

Covalently Bonded True Hybrid Material<\/h2>\n

\u201cThe nanotubes actually become one with the material in certain places,\u201d Tour said. \u201cIt\u2019s a true hybrid with in-plane nanotubes covalently bonded<\/a> to graphene.\u201d<\/p><\/blockquote>\n

The graphene is strengthened by the interconnected, embedded nanotubes.<\/p>\n

\u201cWe can see in our images how well the nanotubes bear the load. When we stretch the material, the tubes get thinner,\u201d said Tour.<\/p><\/blockquote>\n

Since the electron microscope images allow them to them determine the nanotubes\u2019 chirality<\/a> (the angles of the hexagons that make up the tube), the researchers were able to calculate the tubes\u2019 diameters and know exactly how much thinner they get under tension.<\/p>\n

Additionally, the networked nanotubes make the material a better conductor than standard chemical vapor deposition grown graphene, Tour said.<\/p>\n

The Road to Flexible Displays<\/h2>\n

Graphene, as grown, is never a perfect matrix of hexagons; instead, it consists of crystals that grow separately and connect at grain boundaries that disrupt the flow of electrons. The nanotubes in rebar graphene effectively bridge those boundaries.<\/p>\n

\u201cThe big thing for industry is to see if they can get graphene to substitute for ITO for transparent displays,\u201d Tour said. \u201cBut ITO is rigid, and it breaks when you drop your smartphone, for example. Graphene and nanotubes, on the other hand, would afford flexible displays. We showed in our tests that rebar graphene has better conductivity than normal graphene at the same transparency, and with layering, it could be ITO-competitive.\u201d<\/p><\/blockquote>\n

Original Study:<\/strong> Zheng Yan, Zhiwei Peng, Gilberto Casillas, Jian Lin, Changsheng Xiang, Haiqing Zhou, Yang Yang, Gedeng Ruan, Abdul-Rahman O. Raji, Errol L. G. Samuel, Robert H. Hauge, Miguel Jose Yacaman, James M. Tour. Rebar Graphene<\/a> ACS Nano, 2014; 140402145529003 DOI: 10.1021\/nn501132n#sthash.WppbV65B.dpuf<\/p>\n","protected":false},"excerpt":{"rendered":"

Reinforcing bars of carbon nanotubes make two-dimensional graphene much easier to handle, researchers at Rice University have found. The new hybrid, according to Rice chemist James Tour, could, when stacked in a few layers, make a cost-effective alternative for costly indium tin oxide (ITO). ITO is currently used in displays and solar cells. Tour set…<\/p>\n","protected":false},"author":1,"featured_media":651,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[73],"tags":[12,89],"_links":{"self":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts\/648"}],"collection":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/comments?post=648"}],"version-history":[{"count":3,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts\/648\/revisions"}],"predecessor-version":[{"id":654,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/posts\/648\/revisions\/654"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/media\/651"}],"wp:attachment":[{"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/media?parent=648"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/categories?post=648"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/techfragments.com\/wp-json\/wp\/v2\/tags?post=648"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}