Surface Chemistry of Almandine Garnet

Abstract

Almandine garnet is commonly used in abrasive blasting processes to prepare metallic surfaces for painting. However, there is evidence that the process leads to significant amounts of abrasive embedded in the 'cleaned' surface, and hence the surface chemistry of garnet will affect the binding of any coatings subsequently applied. In addition, in marine environments seawater aerosol droplets are expected to impact the exposed surface prior to coating application, depositing both water and dissolved inorganic ions. In this work, we provide in-depth analysis of the chemistry of the almandine garnet surface using angle-resolved X-ray photoelectron spectroscopy (XPS) and note a correlation for several elemental oxides between literature values of the binding energy of the surface oxygen 1s XPS peak and the basicity of the hydroxyl group that forms on the surface.We also consider the adsorption to almandine garnet powder of seawater-relevant inorganic ions (sodium, magnesium, and calcium): Binding constants have been determined using titration measurements, solution-depletion isotherms, and numerical modelling, with calcium observed to bind more strongly than magnesium. The relevance of Langmuir-type fits to constant-pH adsorption isotherms is discussed. By contrast, sodium either binds very weakly or is effectively inert towards 2 the garnet surface under the experimental conditions. The complex adsorption behaviour observed emphasizes the necessity of using multiple techniques to characterize mineral surfaces.

The Bonding Mechanism of the Micro-Interface of Polymer Coated Steel

“…With the substantial improvement of computer performance, computer simulation technology has become a powerful tool for us to study the micro-scale of materials. According to previous research, the first principles of quantum mechanics (QM) and molecular dynamics (MD) have become advantageous tools for studying the interaction mechanism between metals and non-metals [21][22][23][24]. MD can simulate the interaction law between atoms in a defined complex system on the atomic scale [25][26][27][28].…”

Abrading-Induced Breakdown of Ag Nanoparticles into Atomically Dispersed Ag for Enhancing Antimicrobial Performance

“…As shown in Figure S13, the O 1s peak of Ag/Al 2 O 3 –0 is located at 531.0 eV, while that of Ag/Al 2 O 3 –20 is negatively shifted to 530.8 eV. The O 1s peak of γ-Al 2 O 3 can be deconvoluted into two peaks at 530.6 and 532.3 eV, attributed to lattice oxygen and surface OH groups, respectively. − The fractions of OH groups out of total oxygen are calculated based on peak area, and the values decrease from 40.0 to 31.1 to 23.1% for γ-Al 2 O 3 to Ag/Al 2 O 3 –0 to Ag/Al 2 O 3 –20, respectively (Figure B). Hence, loading of AgNPs on γ-Al 2 O 3 surfaces depletes OH groups, and atomization of AgNPs depletes OH groups even further.…”

Raman-XPS spectroscopic investigation of heavy mineral sands along Indian coast

“…The Si2p has two peaks with the binding energies of 100.65 eV and 101.97 eV, corresponding to Si2p 3/2 and Si2p 1/2 of the bulk aluminosilicate framework (Fig. 6c) (Poon et al 2020). The high resolution spectra of O1s consist of two peaks at 529.68 eV and 531.68 eV (Fig.…”