CMSP Seminar @ICTP Stasi Room: Monday 3 July at 11 am: Angelo BONGIORNO

[Condensed Matter Section]

Condensed Matter and Statistical Physics Seminar

Monday, 3 July at 11:00 a.m.
Venue: STASI Seminar Room, first floor, ICTP Leonardo building
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*Spea**ker: Angelo BONGIORNO *
(Dept. of Chemistry , College of Staten Island, CUNY and
CUNY Graduate Centre, New York, NY, USA)

Title: *S**tructure and Mechanical Pr**operties of Pristine and Oxidized **
**Graphene Films: Computations and Experiments*

Abstract:
Graphene and chemically functionalized graphene are two-dimensional 
materials exhibiting fascinating properties. Technological applications 
of these materials can emerge only from understanding and controlling 
structure and properties at the layer/atomic level. In this talk, I will 
report on our recent atomistic studies of the chemical structure and 
mechanical properties of both pristine and oxidized multilayer graphene 
films on SiC. I will first focus on graphene oxide and present results 
of a density functional theory study undertaken to interpret puzzling 
X-ray photoelectron spectroscopy and X-ray diffraction measurements. 
Secondly, I will report on atomic force microscope (AFM) indentation 
measurements of the perpendicular-to-the-plane elasticity of 
graphene-based films, and after presenting selected experimental 
results, I will focus on the computations carried out to elucidate the 
elastic behaviors of both the pristine and oxidized graphene films. Key 
topics discussed in this talk include (i) the chemical structure and 
mechanisms underlying the metastable character of epitaxial graphene 
oxide [1,2], (ii) the role played by moisture to influence the elastic 
modulus and structure of the graphene oxide films [3,4], and (iii) the 
unusual mechanical response exhibited by a bilayer graphene film on SiC 
when indented by an AFM tip [4].

[1] S. Kim, S. Zhou, Y. Hu, M. Acik, Y.J. Chabal, C. Berger, W. de Heer, 
A. Bongiorno, and E. Riedo, Room-temperature metastability of multilayer 
graphene oxide films, Nature Materials 11, 544 (2012).
[2] S. Zhou and A. Bongiorno, Density Functional Theory Modeling of 
Multilayer “Epitaxial” Graphene Oxide, Accounts of Chemical Research 47, 
3331 (2014).
[3] S. Zhou, S. Kim, E. Di Gennaro, Y. Hu, C. Gong, C.-Y. Chang, X. Lu, 
H.-C. Chiu, C. Berger, W. de Heer, E. Riedo, Y.J. Chabal, C. Aruta, and 
A. Bongiorno, Film structure of epitaxial graphene oxide on SiC: Insight 
on the relationship between interlayer spacing, water content, and 
intralayer structure, Advanced Materials Interfaces 1, 1300106 (2014).
[4] Y. Gao, S. Kim, S. Zhou, H.-C. Chiu, D. Nélias, C. Berger, W. de 
Heer, R. Sordan, L. Polloni, A. Bongiorno, and E. Riedo, Elastic 
coupling between layers in two-dimensional materials, NaturMaterials 14, 
714 (2015).



All are welcome to attend.