Papers by Michail Georgakis
Microporous and Mesoporous Materials, 2014
In this paper we investigate the effect of graphene pores’ alterations on hydrogen molecular adso... more In this paper we investigate the effect of graphene pores’ alterations on hydrogen molecular adsorption. The alterations take place in three ways: insertions at different amount of oxygen functional groups on the graphene structure, carbon atoms substitution by boron ones, and insertion of three alkyl groups. Totally one graphene pore model, six oxygenated models, two boron substituted models and three alkyl models were constructed. Hydrogen physical adsorption process was simulated via Molecular Dynamics at 77 K. Our results show that there is optimum oxygen and boron percentage for adsorption energy and gravimetric adsorption of hydrogen. On the other hand the insertion of alkyl groups leads to loss of adsorption capacity and reduction of adsorption energy for all three models.
International Journal of Hydrogen Energy, 2007
This work attempts to shed light on molecular hydrogen adsorption in carbonaceous microporous mat... more This work attempts to shed light on molecular hydrogen adsorption in carbonaceous microporous materials by exploiting molecular dynamics simulations combined with geometry optimization calculations of the solid structures. Carbon structures were considered here because of evidence suggesting that they may be efficient media for hydrogen storage. The inclusion of oxygen functional groups in these solid structures was also examined since they could affect hydrogen adsorption. Insertion of oxygen functional groups causes a decrease in hydrogen adsorption and this effect is more evident in narrow pores. Hydrogen molecules adsorb in the pores as structured layers, depending on pore slit width. The amount of hydrogen adsorbed reached 4.41% w/w for the purely carbonaceous materials, whereas for the oxygenated materials adsorption was limited to 3.30% w/w. The estimated adsorption density inside the pores exceeded the liquid hydrogen density for both solid structures investigated.
International Journal of Molecular Sciences, 2021
SARS-CoV-2 currently lacks effective first-line drug treatment. We present promising data from in... more SARS-CoV-2 currently lacks effective first-line drug treatment. We present promising data from in silico docking studies of new Methisazone compounds (modified with calcium, Ca; iron, Fe; magnesium, Mg; manganese, Mn; or zinc, Zn) designed to bind more strongly to key proteins involved in replication of SARS-CoV-2. In this in silico molecular docking study, we investigated the inhibiting role of Methisazone and the modified drugs against SARS-CoV-2 proteins: ribonucleic acid (RNA)-dependent RNA polymerase (RdRp), spike protein, papain-like protease (PlPr), and main protease (MPro). We found that the highest binding interactions were found with the spike protein (6VYB), with the highest overall binding being observed with Mn-bound Methisazone at -8.3 kcal/mol, followed by Zn and Ca at -8.0 kcal/mol, and Fe and Mg at -7.9 kcal/mol. We also found that the metal-modified Methisazone had higher affinity for PlPr and MPro. In addition, we identified multiple binding pockets that could be ...
International Journal of Hydrogen Energy, 2007
This work aims at resolving the discrepancy between theoretical predictions on the physical adsor... more This work aims at resolving the discrepancy between theoretical predictions on the physical adsorption of molecular hydrogen on carbonaceous solids, by exploiting molecular dynamics simulations of the adsorption process. In continuance of our previous work, three models were constructed for the depiction of the microporous carbonaceous structure. The first one (SSM) consisted of only two parallel sheets, being the lightest one used. The second (IHM) and third (HWM) models comprised structural imperfections in the form of pits and holes into their structure. Structural imperfections seemed to have a slight augmentative effect on the adsorption process. It was concluded that the addition of extra sheets to the walls did not result to any enhancement of the adsorption efficiency of the solid model. On the contrary, the lightest model exhibited superb results for the % weight-by-weight adsorption of hydrogen, approaching the highest value reported. Finally, a couple of suggestions on the development of a material for the storage of hydrogen were derived, based on the above conclusions.
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Papers by Michail Georgakis