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This contribution investigates chlorine (Cl) interaction with the Fe(100) surface, with a focus on governing adsorption energies and geometrical features at the nanoscale using the density functional theory (DFT) approach. The Cl/Fe(100) system can be considered as a building block to create nanosystems with specific and desired electronic, material, mechanical, or environmental properties. We report adsorption energies, surface relaxations. and buckling distances for Cl adsorbed as a function of Cl coverage. The computational DFT framework employs a vdW-DF functional with coverages varying from 0.25 to 1 ML. Adsorption at a bridge site with coverage of 0.5 ML appears to be the most preferred site, with an adsorption energy of −4.44 eV. For all coverages, Cl adsorption at the bridge and hollow sites incurs slightly higher adsorption energies than adsorption at the top (T) site. The potential energy surface (PES) for the dissociation of a Cl molecule over the Fe(100) surface was calculated. Dissociative adsorption of the Cl molecule on Fe(100) ensues via a modest activation barrier of only 0.58 eV in a noticeably exothermic reaction of 2.94 eV. In agreement with experimental observations, the work function decreases upon Cl addition in reference to the clean iron surface. The electronic interaction between Cl and the Fe(100) surface was examined by calculating the differential charge density distribution of the most stable structure (B-0.5 ML). The vdW-DF interactions increase the adsorption energies and reduce the equilibrium distances when compared with the corresponding results from plain DFT.

In this study, the effects of polyaniline (PANI) incorporation (3 wt% of PANI) and graphene nanoplatelets (GNPs) loading (0.1–0.7 wt%) on the mechanical, thermal, and electrical performance of epoxy matrix were investigated. The incorporation of 0.3 wt% GNPs optimally enhanced the bending strength, bending modulus, tensile strength, tensile modulus, and impact strength (90 MPa, 1422 MPa, 63 MPa, 602 MPa, and 8.29 kJm−2, respectively). At 0.3 wt% GNPs, the hybridization effect optimally enhanced the glass transition behaviour of the epoxy nanocomposites. The electrical and thermal conductivities of epoxy were improved upon the inclusion of PANI, and this increase was further augmented when the GNPs content increased to 0.3 wt%. However, higher GNPs contents deteriorated the mechanical performance and electrical and heat conduction. Field emission scanning electron microscopy showed good filler distribution and effective interactions among the GNPs, PANI, and epoxy components with appropriate compositions.

This study represents detailed density functional theory (DFT) calculations with the inclusion of Van der Waals correction to investigate the adsorption of a methanethiol (CH3SH) molecule on a Fe(110) surface. We report herein the structural geometries and binding energies for all plausible molecular and dissociative interactions of the molecule with the surface. The CH3SH molecule is found to interact weakly with the Fe(110) surface in the physisorption adsorption, forming several configurations with different orientations and the most preferred site with a binding energy of 0.72 eV. Dissociation of a CH3SH molecule on this surface is found to be preferred with an energy of 6.04 eV. [ABSTRACT FROM AUTHOR]

Interaction of water with [Cu.sub.2]O has many prominent industrial and environmental applications. This study represents detailed density-functional theory calculations investigating the adsorption of a water molecule on a [Cu.sub.2]O(110):CuO surface; [...]

In this study, we report a comprehensive density functional theory investigation of the structure and thermodynamic stability of FeCl2 and FeCl3 surfaces. Calculated lattice constants and heats of formation for bulk FeCl2 and FeCl3 were found to be in relatively good agreement with experimental measurements. We provide structural parameters for 15 distinct FeCl2 and FeCl3 surfaces along the three low-index orientations. The optimized geometries for all surfaces are compared with analogous bulk values. Ab initio atomistic thermodynamic calculations have been carried out to assess the relative thermodynamic stability of FeCl2 and FeCl3 surfaces under practical operating conditions of temperatures and pressures. The FeCl2 (100-Cl) surface is found to afford the most stable configuration at all experimentally accessible gas phase conditions. [ABSTRACT FROM AUTHOR]

Conventional polymer blending has a shortcoming in conductivity characteristic. This research addresses the preparation of conductive thermoplastic natural rubber (TPNR) blends with graphene nanoplates (GNPs)/polyaniline (PANI) through melt blending using an internal mixer. The effect of PANI content (10, 20, 30, and 40 wt %) on the mechanical and thermal properties, thermal and electrical conductivities, and morphology observation of the TPNR/GNPs/PANI nanocomposites was investigated. The results showed that the tensile and impact properties as well as thermal conductivity of nanocomposite had improved with the incorporation of 3 wt % of GNPs and 20 wt % of PANI as compared to neat TPNR and reduced with further increase of the PANI content. It was observed that the GNPs and PANI acted as a critical component to improve the thermal stability and electrical conductivity of the TPNR/GNPs/PANI nanocomposites. The most improved conductivity of 5.22 E‐5 S/cm was observed at 3 wt % GNPs and 40 wt % PANI. Variable‐pressure scanning electron microscopy micrograph revealed the good interaction and distribution of GNPs and PANI within TPNR matrix at PANI loadings lower than 30 wt %. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48873. [ABSTRACT FROM AUTHOR]

These contributions explore interaction modes between the methanethoil (CH3SH) molecule and the Fe(100) surface via implementing accurate density functional theory (DFT) calculations with the inclusion of van der Waals corrections. We consider three adsorption sites over the Fe(100) surface, namely, top(T), bridge (B), and hollow (H) sites as potential catalytic active sites for the molecular and dissociative adsorption of the CH3SH molecule. The molecular adsorption structures are found to occupy either B or T sites with former sites holding higher stability by 0.17 eV. The inclusion of van der Waals corrections refound to slightly alter adsorption energies. For instance, adsorption energies increased by ~0.18 and ~0.21 eV for B and T structure, respectively, in reference to values obtained by the plain generalized gradient approximation (GGA) functional. A stability ordering of the dissociation products was found to follow the sequence (CH4, S) > (CH3, S, H) > (─SCH3, H) > (─CH3, SH). The differential charge density distributions were examined to underpin prominent electronic contributing factors. Direct fission of C─S bond in the CH3SH molecule attains exothermic values in the range 2.0 to 2.1 eV. The most energetically favorable sites for the surface‐mediated fission of the thiol's S─H bond correspond to the structure where the ─SCH3 and H are both situated on hollow sites with an adsorption energy of −2.43 eV. Overall, we found that inclusion of van der Waals functional to change the binding energies more noticeably in case of dissociative adsorption structures. The results presented herein should be instrumental in efforts that aim to design stand‐alone Fe desulfurization catalysts. [ABSTRACT FROM AUTHOR]

Scanning tunneling microscopy (STM) and density functional theory calculations are used for studying the adsorption of a simple ketone to the silicon (001) surface. The use of the carbonyl functional group to tether organic molecules to silicon has led to enhanced stability of the adsorbates with respect to current-voltage characterization.

Interaction of water with Cu2O has many prominent industrial and environmental applications. This study represents detailed density-functional theory calculations investigating the adsorption of a water molecule on a Cu2O(110):CuO surface; one of the two most stable Cu2O surfaces under practical catalytic conditions of temperatures and pressures. We report herein structural geometries and binding energies for all plausible molecular and dissociative interaction of H2O with the surface. The water molecule is found to interact weakly with the Cu2O(110):CuO surface, forming several vertical and flat orientations where the latter was found to offer the most preferred site with a binding energy at 0.389 eV. Dissociation of a water molecule on this surface is found to incur a modest endothermcity of 0.71 eV. [ABSTRACT FROM AUTHOR]

First-principle density functional theory (DFT) and a periodic-slab model have been utilized to investigate the structure of the CuCl2(100) surface. Structural parameters of the bulk CuCl2 are reported and compared with the experimental values. The structure of the CuCl2(100) is calculated using a (2 × 2) supercell. Structural parameters in terms of bond lengths and bond angle are calculated. Electronic properties of the CuCl2(100) surface are investigated by calculating the density of state (DOS) and the projected density of state for a slab containing five layers. [ABSTRACT FROM AUTHOR]