The role of hydrogen bonding in interaction energy at the interface of conductive polymers and modified graphene-based nanosheets: A reactive molecular dynamics study

2018 ◽  
Vol 155 ◽  
pp. 499-523 ◽  
Author(s):  
Giti Pishehvarz ◽  
Hamid Erfan-Niya ◽  
Esmaeil Zaminpayma
Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5853
Author(s):  
Sulejman Skoko ◽  
Matteo Ambrosetti ◽  
Tommaso Giovannini ◽  
Chiara Cappelli

We present a detailed computational study of the UV/Vis spectra of four relevant flavonoids in aqueous solution, namely luteolin, kaempferol, quercetin, and myricetin. The absorption spectra are simulated by exploiting a fully polarizable quantum mechanical (QM)/molecular mechanics (MM) model, based on the fluctuating charge (FQ) force field. Such a model is coupled with configurational sampling obtained by performing classical molecular dynamics (MD) simulations. The calculated QM/FQ spectra are compared with the experiments. We show that an accurate reproduction of the UV/Vis spectra of the selected flavonoids can be obtained by appropriately taking into account the role of configurational sampling, polarization, and hydrogen bonding interactions.


Biochemistry ◽  
2016 ◽  
Vol 55 (27) ◽  
pp. 3834-3846 ◽  
Author(s):  
Melek N. Ucisik ◽  
Philip C. Bevilacqua ◽  
Sharon Hammes-Schiffer

2015 ◽  
Vol 1726 ◽  
Author(s):  
Pedro A. S. Autreto ◽  
Douglas S. Galvao

ABSTRACTGraphyne is a generic name for a carbon allotrope family of 2D structures, where acetylenic groups connect benzenoid rings, with the coexistence of sp and sp2 hybridized carbon atoms. In this work we have investigated, through fully atomistic reactive molecular dynamics simulations, the dynamics and structural changes of the hydrogenation of α, β, and γ graphyne forms. Our results showed that the existence of different sites for hydrogen bonding, related to single and triple bonds, makes the process of incorporating hydrogen atoms into graphyne membranes much more complex than the graphene ones. Our results also show that hydrogenation reactions are strongly site dependent and that the sp-hybridized carbon atoms are the preferential sites to chemical attacks. In our cases, the effectiveness of the hydrogenation (estimated from the number of hydrogen atoms covalently bonded to carbon atoms) follows the α, β, γ-graphyne structure ordering.


Author(s):  
Ikuo Kurisaki ◽  
Shigenori Tanaka

ATPase and GTPase have been widely found as chemical energy-mechanical work transducers, whereas the physicochemical mechanisms are not satisfactorily understood. We addressed the problem by examining John Ross’ conjecture that...


2011 ◽  
Vol 1284 ◽  
Author(s):  
Pedro A. S. Autreto ◽  
Marcelo Z. Flores ◽  
Sergio B. Legoas ◽  
Ricardo P. B. Santos ◽  
Douglas S. Galvao

ABSTRACTRecently, Elias et al. (Science 323, 610 (2009).) reported the experimental realization of the formation of graphane from hydrogenation of graphene membranes under cold plasma exposure. In graphane, the carbon-carbon bonds are in sp3 configuration, as opposed to the sp2 hybridization of graphene, and the C–H bonds exhibit an alternating pattern (up and down with relation to the plane defined by the carbon atoms). In this work we have investigated, using reactive molecular dynamics simulations, the role of H frustration (breaking the H atoms up and down alternating pattern) in graphane-like structures. Our results show that a significant percentage of uncorrelated H frustrated domains are formed in the early stages of the hydrogenation process, leading to membrane shrinkage and extensive membrane corrugations. This might explain the significant broad distribution of values of lattice parameter experimentally observed. For comparison purposes we have also analyzed fluorinated graphane-like structures. Our results show that similarly to H, F atoms also create significant uncorrelated frustrated domains on graphene membranes.


2018 ◽  
Vol 20 (16) ◽  
pp. 11053-11066 ◽  
Author(s):  
Dongshuai Hou ◽  
Tiejun Yang

Heterogeneous hydrogen bonding determines the mechanical properties of GO sheets.


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