Method for the Calculation of the Hamaker Constants of Organic Materials by the Lifshitz Macroscopic Approach with Density Functional Theory

Abstract

The Hamaker constants, which are coefficients providing quantitative information on intermolecular forces, were calculated for a number of different materials according to the Lifshitz theory via simple DFT calculations without any experimental measurements being performed. The physical properties (polarizability, dipole moment, molecular volume, and vibrational frequency) of organic molecules were calculated using the B3LYP density functional and the aug-cc-pVDZ basis set. Values for the Hamaker constants were obtained using the approximation of the Lorentz-Lorenz equation and Onsager's equation with these properties. It was found that, in the case of 'non-associative' materials, like hydrocarbons, ethers, ketones, aldehydes, carboxylic acids, esters, nitriles, and hydrosilanes, and halides, the calculated Hamaker constants were similar in value to their experimentally determined counterparts. Moreover, with this calculation method, it is easy to create the molecular model and the CPU time can be shortened.

Vibrational mode contribution to the dielectric permittivity of disordered small-molecule organic semiconductors

“…We have not performed separate calculations of α el . Firstprinciples and machine-learning studies for (mostly) smaller molecules than those studied in this paper suggest that performing electronic polarizability calculations with a sufficient accuracy could soon be within reach [55][56][57][58][59][60][61]. Instead, we will use for all materials a value of n = 1.7, independent of the mode frequency, so r,∞ = n 2 = 2.89.…”

Interface Modeling for the Ab Initio Evaluation of the Water Contact Angle on a Metallic Cu(111) Surface

“…Choice of exchange-correlation potentials DFT predictions are known to critically depend on the choice of exchange-correlation potentials. [2,3,27] Because we are dealing with the adsorption of a monolayer of water molecules, chemisorption would be dominant, so we did not consider dispersion interactions [28] when employing GGA-PBE for the exchange-correlation potential. However, correcting for dispersion interactions [29,30] may affect the present results.…”

“…Regulating the wettability of surfaces [1][2][3] is an important issue that must be addressed to broaden their industrial applications, such as heterogeneous catalysis, corrosion, and electrochemistry. [1,4,5] The wettability of the surfaces of metal catalysts such as Cu has a significant effect on their catalytic activity for electrochemical reactions, [6] wherein the receding contact angle of water on the metal surface corresponds to the oxygen reduction reactions of the catalyst.…”

Selective Transfer of Si Thin-Film Microchips by SiO2 Terraces on Host Chips for Fluidic Self-Assembly

“…By using this equation, we calculated A for several representative systems. For the Hamaker constants of the materials used for the calculations, we employed the literature values [20][21][22][23][24][25]. We chose Si 3 N 4 , HfO 2 , and ZrO 2 as representative of high-k dielectrics, and silsesquioxanes and allyl ethers as representative of low-k dielectrics.…”

“…We chose Si 3 N 4 , HfO 2 , and ZrO 2 as representative of high-k dielectrics, and silsesquioxanes and allyl ethers as representative of low-k dielectrics. Because we could not find a value of the Hamaker constants of silsesquioxanes, we assumed it as 5.5 × 10 −20 J deduced from the values of 5.5 × 10 −20 J and 5.4 × 10 −20 J for disiloxane and hexamethylcyclotrisiloxane, respectively [25]. Similarly, we assumed the representative Hamaker constant of allyl ethers as 4.5 × 10 −20 J from the values of 4.1 × 10 −20 J and 4.9 × 10 −20 J for dipropyl ether and allyl acetate, respectively [25].…”