RESUMO
Graphene and its allotropes have attracted attention due to their special electronic, mechanical, and thermal properties. Numerous studies investigate their wetting behavior. Tetrahexcarbon (THC) is a new carbon allotrope and is obtained from pentagraphene. This research, examines THC's wettability properties using reactive molecular dynamics (MD) and density functional theory (DFT) simulations. The results of molecular dynamics simulation reveal that THC is a hydrophobic substrate with a contact angle of 113.4° ± 2.8°. Using molecular dynamics, this research also evaluates quantities such as contact diameter, dipole moment, and density profile of water droplet. In addition, hydrogen and oxygen atoms' distribution functions, hydrogen bonds, path of the droplet's center of mass, and potential energy surface are presented. According to the simulation results, the droplet's structure on THC is slightly layered. Also, the water molecules' orientations in the interface are such that they do not allow the hydrogen bonds to form between water molecules and the THC substrate. The results of MD show that there are two different behavioral patterns for the hydrogen bonds between and within the water droplet's layers. Furthermore, this research utilizes DFT and AIMD in order to show how a water molecule interacts with THC. DFT exhibits that the water molecule's hydrogen atoms are toward the substrate. But an opposite configuration happens in the droplet-THC interface. The results of the atoms-in-molecules (AIM) theory indicate that there is a weak interaction between the water molecules and the THC substrate. The thermochemical results reveal that water molecules' adsorption is within the range of physical adsorption. Finally, NBO analysis shows that the THC's carbon atoms have a permanent partial charge. These results confirm that the THC is a hydrophobic material.
RESUMO
The experimental synthesis of biphenylene, a two-dimensional carbon allotrope, theoretically predicted in 1997, took place in 2021. Biphenylene is also called net C. Two close relatives of this structure, known as net W and net Y, have not yet been experimentally synthesized. In this article, the wettability properties of these three carbon allotropes are investigated, using molecular dynamics simulation. The electronic and mechanical properties of these allotropes have been extensively studied, but their wettability properties are unknown. The chemical structure of the three allotropes is similar and contain four, six, and eight carbon membered rings. The results of molecular dynamics calculations with reactive potential show that net C, net W and net Y are hydrophobic substrates with contact angles of 122.3° ± 1.3°, 126.2° ± 1.3° and 127.8° ± 1.2°, respectively. The droplets on the above-mentioned substrates have a completely layered structure. That is, the water molecules inside the droplet are completely placed in certain layers. Calculating the order parameter for water molecules shows that the degree of water molecules' tetrahedrality on all three substrates is exactly the same. In terms of hydrogen bonding at the interface, the three substrates act identically and show almost the same effect. The droplet displacement is the highest on net W and the lowest on net Y. Furthermore, the van der Waals potential on all three substrates has been scanned. It is demonstrated that the amount of droplet displacement on the surface is inversely related to the surface density of the potential peaks.
