[{"@context":"https:\/\/schema.org\/","@type":"Article","@id":"https:\/\/www.dorso.cz\/super-silny-grafen-ma-achillovu-patu\/#Article","mainEntityOfPage":"https:\/\/www.dorso.cz\/super-silny-grafen-ma-achillovu-patu\/","headline":"Super-siln\u00fd grafen m\u00e1 Achillovu patu","name":"Super-siln\u00fd grafen m\u00e1 Achillovu patu","description":"Grafen je \u010dasto nab\u00edzen jako z\u00e1zra\u010dn\u00fd materi\u00e1l – snadno vede elekt\u0159inu a je stokr\u00e1t siln\u011bj\u0161\u00ed ne\u017e ocel. Ale nyn\u00ed testy skute\u010dn\u00fdch vzork\u016f grafenu ukazuj\u00ed, \u017ee zat\u00edmco uhl\u00edkat\u00fd materi\u00e1l je mo\u017en\u00e1 nejsiln\u011bj\u0161\u00edm materi\u00e1lem vyr\u00e1b\u011bn\u00fdm dnes, je tak\u00e9 k\u0159ehk\u00fd jako b\u011b\u017en\u00e1 keramika. \u00a0 \u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 V\u00fdsledek? Je n\u00e1chyln\u00fd k prasknut\u00ed. \u00a0 Struktura grafenu","datePublished":"2017-08-27","dateModified":"2023-05-19","author":{"@type":"Person","@id":"https:\/\/www.dorso.cz\/author\/#Person","name":"","url":"https:\/\/www.dorso.cz\/author\/","identifier":1,"image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/1e120f96477763896a9e7ab3663c076bf8b67ca32fa1a5943b70761da502a7a7?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/1e120f96477763896a9e7ab3663c076bf8b67ca32fa1a5943b70761da502a7a7?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"dorso.cz","logo":{"@type":"ImageObject","@id":"\/logo.png","url":"\/logo.png","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/www.dorso.cz\/wp-content\/uploads\/img_a298878_w2380_t1509078637.png","url":"https:\/\/www.dorso.cz\/wp-content\/uploads\/img_a298878_w2380_t1509078637.png","height":0,"width":0},"url":"https:\/\/www.dorso.cz\/super-silny-grafen-ma-achillovu-patu\/","wordCount":407,"articleBody":"Grafen je \u010dasto nab\u00edzen jako z\u00e1zra\u010dn\u00fd materi\u00e1l – snadno vede elekt\u0159inu a je stokr\u00e1t siln\u011bj\u0161\u00ed ne\u017e ocel. Ale nyn\u00ed testy skute\u010dn\u00fdch vzork\u016f grafenu ukazuj\u00ed, \u017ee zat\u00edmco uhl\u00edkat\u00fd materi\u00e1l je mo\u017en\u00e1 nejsiln\u011bj\u0161\u00edm materi\u00e1lem vyr\u00e1b\u011bn\u00fdm dnes, je tak\u00e9 k\u0159ehk\u00fd jako b\u011b\u017en\u00e1 keramika.\u00a0\u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 V\u00fdsledek? Je n\u00e1chyln\u00fd k prasknut\u00ed.\u00a0Struktura grafenu je velmi citliv\u00e1 na p\u0159\u00edtomnost prasklin. V oceli, pokud m\u00e1te prasklinu, nen\u00ed to tak nebezpe\u010dn\u00e9. Ocel m\u00e1 obrovskou odolnost v\u016f\u010di prodlu\u017eov\u00e1n\u00ed trhlin. Grafen je sp\u00ed\u0161e jako okenn\u00ed sklo.\u00a0M\u00edra odolnosti materi\u00e1lu v\u016f\u010di trhlin\u00e1m, naz\u00fdvan\u00e1 lomov\u00e1 hou\u017eevnatost, tedy pravd\u011bpodobnost, \u017ee se zlom\u00ed, kdy\u017e se roztrhne. Tak\u00e9 m\u011b\u0159\u00ed, kolik lom\u016f m\u016f\u017ee dan\u00e1 l\u00e1tka vydr\u017eet p\u0159ed prasknut\u00edm p\u0159i p\u0159ekroucen\u00ed. Kovy jsou nap\u0159\u00edklad tv\u00e1rn\u00e9. Trv\u00e1 pom\u011brn\u011b dlouho, ne\u017e se l\u017e\u00edce po \u010dast\u00e9m oh\u00fdb\u00e1n\u00ed a kroucen\u00ed zlom\u00ed. Sklen\u011bn\u00fd kus odol\u00e1v\u00e1 zkroucen\u00ed, ale snadno se rozbije.\u00a0Grafen s trhlinami je 10kr\u00e1t n\u00e1chyln\u011bj\u0161\u00ed k rozbit\u00ed ne\u017e ocel a bl\u00ed\u017e\u00ed se svou l\u00e1mavou hou\u017eevnatost\u00ed ke keramice na b\u00e1zi oxidu hlinit\u00e9ho nebo karbidu k\u0159em\u00edku.\u00a0Pom\u011brn\u011b n\u00edzk\u00e1 lomov\u00e1 hou\u017eevnatost znamen\u00e1, \u017ee pokud se v grafenu objev\u00ed mal\u00e1 trhlina, specifick\u00e9 vlastnosti grafenu se oslab\u00ed. Jen\u017ee mal\u00e9 trhliny ve struktu\u0159e grafenu jsou p\u0159irozen\u00fdm d\u016fsledkem jeho v\u00fdroby.\u00a0Grafen je vyr\u00e1b\u011bn n\u011bkolika zp\u016fsoby, mezi n\u011b\u017e pat\u0159\u00ed chemick\u00e9 vylu\u010dov\u00e1n\u00ed z plynn\u00e9 f\u00e1ze, p\u0159i n\u00ed\u017e se uhl\u00edkov\u00e1 p\u00e1ra nech\u00e1 vychladnout a usad\u00ed se na povrchu, a exfoliace, v n\u00ed\u017e se grafit (z n\u011bho\u017e poch\u00e1z\u00ed grafen) vlo\u017e\u00ed do rozpou\u0161t\u011bdla. Listy grafenu mohou b\u00fdt velk\u00e9 p\u0159i v\u00fdrob\u011b exfoliac\u00ed, ale nejsou dokonal\u00e9. V\u00fdsledn\u00e1 m\u0159\u00ed\u017eka atom\u016f uhl\u00edku, kter\u00e1 tvo\u0159\u00ed grafen, m\u00e1 mal\u00e9 vady – chyb\u011bj\u00edc\u00ed atomy nebo nespr\u00e1vn\u011b uspo\u0159\u00e1dan\u00e1 struktura. Chyby nebudou m\u00edt velk\u00fd vliv na pou\u017eit\u00ed grafenu jako vodi\u010de nebo polovodi\u010de, ale pro mechanick\u00e9 aplikace, jako je nap\u0159\u00edklad flexibiln\u00ed zobrazen\u00ed nebo zv\u00fd\u0161en\u00ed strukturn\u00ed s\u00edly jin\u00fdch materi\u00e1l\u016f, jsou tyto z\u00e1vady z\u00e1sadn\u00ed.\u00a0Perfektn\u00ed grafen m\u016f\u017ee odolat tlaku asi 100 GPa, ne\u017e se zlom\u00ed. Ale nedokonal\u00fd grafen, vydr\u017e\u00ed jen mal\u00fd zlomek t\u00e9to hodnoty, asi 4 MPa.                                                                                                                                                                                                                                                                                                                                                                                        4.3\/5 - (10 votes)        "},{"@context":"https:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Super-siln\u00fd grafen m\u00e1 Achillovu patu","item":"https:\/\/www.dorso.cz\/super-silny-grafen-ma-achillovu-patu\/#breadcrumbitem"}]}]