Computational Studies on Polymer Adhesion at the Surface of γ-Al₂O₃. I. The Adsorption of Adhesive Component Molecules from the Gas Phase

Abstract

We calculate the minimum energy paths and reaction energies of the adsorption of the epoxide adhesive components diglycidylesterbisphenol A (DGEBA), diethyltriamine (DETA), and the adhesion promoter 3-aminopropylmethoxysilane (AMEO) at two different sites on a model of the native Al2O3 surface, using the nudged elastic band algorithm in conjunction with self-consistent charge-density functional based tight binding. Our results show that the chosen combination of methods is well suited to obtain an overview of the reaction mechanisms and kinetics of the adsorption of organic molecules on inorganic surfaces. The obtained MEP-s show that there is preference for the adsorption of the adhesion promoter, AMEO, over the resin, DGEBA, while the adsorption of the curing agent, DETA, is unfavorable. Our approach also gives an insight into the ranges of the mechanical and electronic influences of the adsorption process on the interface, which neither full ab initio methods nor force field approaches can provide. These results will help to develop a quantum mechanics-molecular mechanics multiscale embedding scheme for more detailed studies of organic/inorganic hybrid interface reactions.

On the early stage of aluminum oxidation: An extraction mechanism via oxygen cooperation

“…Bulk γ -Al 2 O 3 has long been described as a highly defective spinel lattice, giving rise to a pseudo-amorphous structure as described in Ref. 26. Recently, several studies did show that γ -Al 2 O 3 can also be constructed as a defective hausmannite Mn 3 O 4 structure [26][27][28] where Al atoms replace Mn.…”

“…26. Recently, several studies did show that γ -Al 2 O 3 can also be constructed as a defective hausmannite Mn 3 O 4 structure [26][27][28] where Al atoms replace Mn. Interestingly, the octahedrons and tetrahedrons in hausmannite, oriented along the [1-10] direction, show structures similar to those shown in Fig.…”

Molecular Understanding of the Adhesive Force between a Metal Oxide Surface and an Epoxy Resin: Effects of Surface Water

“…4446 The adhesion surface was modeled by £-alumina (001) surface because the surface is well known as a cleaved surface of £-alumina and some studies have been performed on the (001) surface of £-alumina. 4446 The model of the hydroxylated £-alumina (001) surface was prepared by the same method as our previous work, 27 where the model of Raybaud and coworkers 42,43 and the procedure of Knaup et al 23 were used. Geometry optimization was performed by using DFT calculations on a model containing 52 atoms (Al 16 51 In all the MD simulations, the system was kept at a constant temperature by using a NVT ensemble with the Nosé-Hoover thermostat.…”

The synthesis of urchin-like γ-Al2O3 hierarchical microspheres from Al foils and its rapid adsorption ability towards Congo red

“…Due to its low density, high hardness and strength, excellent thermal and chemical stability, and good optical properties [1][2][3][4], alumina has been used as catalyst, catalyst support [5,6], adsorbent [4,7] and ceramic [8,9] etc widely. Recently, one dimensional (1D) and two dimensional (2D) nanostructure arrays have attracted extensive interests because of their better charge transportation ability, higher surface area and enhanced mechanical properties.…”