Why does graphene tend to break during mechanical exfoliation?

[wayneyie1986]

Is there any specific physical reason that can explain why graphene produced by tape exfoliation tends to break into fragments instead of remaining as a original size perfect piece? Some of the literature I found only briefly mentions that it's due to certain forces causing graphene to fracture, resulting in the production of small pieces. If possible, providing references to relevant literature would be appreciated. Thanks for the assistance.

 

[Tom.G]

I haven't read the whole report, but it seems to indicate lack of surface cleanliness at the atomic level is an importatnt factor, causing areas of poor adhesion by the tape.

https://www.researchgate.net/profil...phene-and-Other-Two-Dimensional-Materials.pdf

Above found with:
https://www.google.com/search?hl=en&q=graphene+by+tape+exfoliation

NOTE:​

You may have to replace the "www" in the link with "scholar". This depends on what cookies Google has left on your computer.​

Cheers,
Tom

 

[vic0627]

Is there any specific physical reason that can explain why graphene produced by tape exfoliation tends to break into fragments instead of remaining as a original size perfect piece? Some of the literature I found only briefly mentions that it's due to certain forces causing graphene to fracture, resulting in the production of small pieces. If possible, providing references to relevant literature would be appreciated. Thanks for the assistance.

Single-crystalline graphene should not break even if it bended, owing to its high strength. The most likely cause for observed fracture would be grain boundary failure. For few-layer graphene, any possible fracture could be attributed to bending induced tensile stress at one side and compression stress on the opposite side. Still, if they are in single crystal form, it would be rather hard forthem to break either.