{"id":4704,"date":"2013-10-10T09:13:57","date_gmt":"2013-10-10T09:13:57","guid":{"rendered":"http:\/\/innovationsgesellschaft.ch\/?p=4704"},"modified":"2013-11-05T15:08:33","modified_gmt":"2013-11-05T15:08:33","slug":"carbons-new-champion","status":"publish","type":"post","link":"https:\/\/innovationsgesellschaft.ch\/en\/carbons-new-champion\/","title":{"rendered":"Carbon's new champion"},"content":{"rendered":"<p>If they do, they\u2019ll find carbyne nanorods or nanoropes have a host of remarkable and useful properties, as described in a new paper by Rice University theoretical physicist Boris Yakobson and his group. The paper appears this week in the American Chemical Society journal <a title=\"Carbyne From First Principles: Chain of C atoms, a Nanorod or a Nanorope\" href=\"http:\/\/pubs.acs.org\/doi\/abs\/10.1021\/nn404177r\" target=\"_blank\">ACS Nano<\/a>.<\/p>\n<p>Carbyne is a chain of carbon atoms held together by either double or alternating single and triple atomic bonds. That makes it a true one-dimensional material, unlike atom-thin sheets of graphene that have a top and a bottom or hollow nanotubes that have an inside and outside.<\/p>\n<p>According to the portrait drawn from calculations by Yakobson and his group:<\/p>\n<ul>\n<li>Carbyne\u2019s tensile strength \u2013 the ability to withstand stretching \u2013 surpasses \u201cthat of any other known material\u201d and is double that of graphene. (Scientists had already calculated it would take an elephant on a pencil to break through a sheet of graphene.)<\/li>\n<\/ul>\n<ul>\n<li>It has twice the tensile stiffness of graphene and carbon nanotubes and nearly three times that of diamond.<\/li>\n<\/ul>\n<ul>\n<li>Stretching carbyne as little as 10 percent alters its electronic band gap significantly.<\/li>\n<\/ul>\n<ul>\n<li>If outfitted with molecular handles at the ends, it can also be twisted to alter its band gap. With a 90-degree end-to-end rotation, it becomes a magnetic semiconductor.<\/li>\n<\/ul>\n<ul>\n<li>Carbyne chains can take on side molecules that may make the chains suitable for energy storage.<\/li>\n<\/ul>\n<ul>\n<li>The material is stable at room temperature, largely resisting crosslinks with nearby chains.<\/li>\n<\/ul>\n<p>That\u2019s a remarkable set of qualities for a simple string of carbon atoms, Yakobson said.<\/p>\n<p>\u201cYou could look at it as an ultimately thin graphene ribbon, reduced to just one atom, or an ultimately thin nanotube,\u201d he said. It could be useful for nanomechanical systems, in spintronic devices, as sensors, as strong and light materials for mechanical applications or for energy storage.<\/p>\n<p>\u201cRegardless of the applications,\u201d he said, \u201cacademically, it\u2019s very exciting to know the strongest possible assembly of atoms.\u201d<\/p>\n<p>Based on the calculations, he said carbyne might be the highest energy state for stable carbon. \u201cPeople usually look for what is called the \u2018ground state,\u2019 the lowest possible energy configuration for atoms,\u201d Yakobson said. \u201cFor carbon, that would be graphite, followed by diamond, then nanotubes, then fullerenes. But nobody asks about the highest energy configuration. We think this may be it, a stable structure at the highest energy possible.\u201d<\/p>\n<p>Theories about carbyne first appeared in the 19th century, and an approximation of the material was first synthesized in the USSR in 1960. Carbyne has since been seen in compressed graphite, has been detected in interstellar dust and has been created in small quantities by experimentalists.<\/p>\n<p>\u201cI have always been interested in the stability of ultimately thin wires of anything and how thin a rod you could make from a given chemical,\u201d Yakobson said. \u201cWe had a paper 10 years ago about silicon in which we explored what happens to silicon nanowire as it gets thinner. To me, this was just a part of the same question.\u201d<\/p>\n<p>The Rice researchers, led by Rice graduate student Mingjie Liu and postdoctoral researcher Vasilii Artyukhov, were aware of a number of papers that described one property or another of carbyne. They set out to detail carbyne with computer models using first-principle rules to determine the energetic interactions of atoms, Artyukhov said.<\/p>\n<p>\u201cOur intention was to put it all together, to construct a complete mechanical picture of carbyne as a material,\u201d Artyukhov said. \u201cThe fact that it has been observed tells us it\u2019s stable under tension, at least, because otherwise it would just fall apart.\u201d<\/p>\n<p>Yakobson said the researchers were surprised to find that the band gap in carbyne was so sensitive to twisting. \u201cIt will be useful as a sensor for torsion or magnetic fields, if you can find a way to attach it to something that will make it twist,\u201d he said. \u201cWe didn\u2019t look for this, specifically; it came up as a side product.\u201d<\/p>\n<p>\u201cThat\u2019s the good thing about studying things carefully,\u201d Artyukhov said.<\/p>\n<p>Another finding of great interest was the energy barrier that keeps atoms on adjacent carbyne chains from collapsing into each other. \u201cWhen you\u2019re talking about theoretical material, you always need to be careful to see if it will react with itself,\u201d Artyukhov said. \u201cThis has never really been investigated for carbyne.\u201d<\/p>\n<p>The literature seemed to indicate carbyne \u201cwas not stable and would form graphite or soot,\u201d he said.<\/p>\n<p>Instead, the researchers found carbon atoms on separate strings might overcome the barrier in one spot, but the rods\u2019 stiffness would prevent them from coming together in a second location, at least at room temperature. \u201cThey would look like butterfly wings,\u201d Artyukhov said.<\/p>\n<p>\u201cBundles might stick to each other, but they wouldn\u2019t collapse completely,\u201d Yakobson added. \u201cThat could make for a highly porous, random net that may be good for adsorption.\u201d Artyukhov said the nominal specific area of carbyne is about five times that of graphene.<\/p>\n<p>When the team\u2019s paper became available this summer on arXiv, the scientific press and even some of the popular press were so excited over the calculations that they picked up on the paper and its implications before the team submitted it for peer review. Now that the complete paper is ready for public consumption, the researchers said they\u2019ll carry their investigation in new directions.<\/p>\n<p>They\u2019re taking a more rigorous look at the conductivity of carbyne and are thinking about other elements as well. \u201cWe\u2019ve talked about going through different elements in the periodic table to see if some of them can form one-dimensional chains,\u201d Yakobson said.<\/p>\n<p>&nbsp;<\/p>\n<p>Source: Rice University<\/p>\n<p>Image: Vasilii Artyukhov\/Rice University (modified)<\/p>\n<p>The full article can be obtained <a title=\"Carbon's new champion\" href=\"http:\/\/news.rice.edu\/2013\/10\/09\/carbons-new-champion\/\" target=\"_blank\">here<\/a> (external link, Rice University).<\/p>\n<p>You might also be interested in the related article on\u00a0<a title=\"Theorists calculate atom-thick carbyne chains may be strongest material ever\" href=\"http:\/\/www.nanowerk.com\/news2\/newsid=32689.php\" target=\"_blank\">Nanowerk\u00a0<\/a> (external link).<\/p>\n<p>The paper published in ACS Nano can be found <a title=\"Carbyne From First Principles: Chain of C atoms, a Nanorod or a Nanorope\" href=\"http:\/\/pubs.acs.org\/doi\/abs\/10.1021\/nn404177r\" target=\"_blank\">here<\/a> (external link, restricted access).<\/p>\n<p>For further information, please contact:<\/p>\n<p>info@innovationsgesellschaft.ch<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Rice University theorists calculate atom-thick carbyne chains may be strongest material ever - if and when anyone can make it in bulk.<\/p>\n","protected":false},"author":22,"featured_media":4698,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[],"class_list":["post-4704","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-nanotechnology"],"_links":{"self":[{"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/posts\/4704","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/comments?post=4704"}],"version-history":[{"count":0,"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/posts\/4704\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/media\/4698"}],"wp:attachment":[{"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/media?parent=4704"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/categories?post=4704"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/innovationsgesellschaft.ch\/en\/wp-json\/wp\/v2\/tags?post=4704"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}