Ultrastrong adhesion of graphene membranes
Ultrastrong adhesion of graphene membranes
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DOI：
10.1038/nnano.2011.123
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发表时间：
2011-09-01
影响因子：
38.3
通讯作者：
Bunch, J. Scott
中科院分区：
文献类型：
--
作者：
Koenig, Steven P.;Boddeti, Narasimha G.;Bunch, J. Scott
随着机械结构进入纳米级范围，货车范德华力的影响增加。石墨烯对于纳米机械系统是有吸引力的（1，2），因为其杨氏模量和强度都固有地高，但是石墨烯的机械行为也受到货车范德华力的强烈影响（3，4）。例如，该力将石墨烯样品夹持到衬底上，并且还将多层样品中的各个石墨烯片保持在一起。在这里，我们使用加压起泡测试来直接测量石墨烯片与氧化硅衬底的粘附能。我们发现单层石墨烯的粘附能为0.45 +/- 0.02 J m（-2），含有2至5个石墨烯片的样品的粘附能为0.31 +/- 0.03 J m（-2）。这些值大于在典型的微机械结构中测量的粘附能，并且与固-液粘附能（5-7）相当。我们将其归因于石墨烯的极端灵活性，这使得它能够符合即使是最光滑的衬底的形貌，从而使其与衬底的相互作用更像液体而不是固体。
As mechanical structures enter the nanoscale regime, the influence of van der Waals forces increases. Graphene is attractive for nanomechanical systems(1,2) because its Young's modulus and strength are both intrinsically high, but the mechanical behaviour of graphene is also strongly influenced by the van der Waals force(3,4). For example, this force clamps graphene samples to substrates, and also holds together the individual graphene sheets in multilayer samples. Here we use a pressurized blister test to directly measure the adhesion energy of graphene sheets with a silicon oxide substrate. We find an adhesion energy of 0.45 +/- 0.02 J m(-2) for monolayer graphene and 0.31 +/- 0.03 J m(-2) for samples containing two to five graphene sheets. These values are larger than the adhesion energies measured in typical micromechanical structures and are comparable to solid-liquid adhesion energies(5-7). We attribute this to the extreme flexibility of graphene, which allows it to conform to the topography of even the smoothest substrates, thus making its interaction with the substrate more liquid-like than solid-like.