Glasses and Optical Materials: Current Issues and Functional Applications: Dissolution and Mechanical Properties of Amorphous Solids
Sponsored by: ACerS Basic Science Division, ACerS Glass & Optical Materials Division
Program Organizers: Jessica Rimsza, Sandia National Laboratories; Delia Brauer, Otto Schott Institute of Materials Research
Monday 10:00 AM
October 18, 2021
Room: B231
Location: Greater Columbus Convention Center
Session Chair: Douglas Meier, Mccrone Associates, Inc.
10:00 AM
X-ray Photoelectron Spectroscopy (XPS) for Improved Characterization of Glass Delamination Lamellae: Douglas Meier1; 1McCrone Associates, Inc.
Glass delamination occurs when a container succumbs to chemical attack from its contents, releasing microscopic thin flakes, or lamellae, of glass into the liquid. These lamellae raise serious quality issues for pharmaceutical manufacturers, so microanalytical investigations are required to determine root cause and inform remediation. Compositional characterization of lamellae by X-ray energy dispersive spectrometry (EDS) results in significant uncertainty, since the EDS information depth (micrometers) exceeds the thickness of typical lamellae (tens of nanometers). The present study addresses this uncertainty by demonstrating X-ray photoelectron spectroscopy (XPS), a compositional analysis technique that features an information depth of a few nanometers. XPS mapping to locate lamellae on a filter, argon ion cluster source etching to preferentially remove organic material from the glass surface, and charge-compensated XPS compositional analysis of both lamellae and the source glass will be demonstrated. These data offer more detailed compositions than EDS, elucidating the delamination mechanism.
10:20 AM
Interactive Corrosion between International Simple Glass (ISG) and Stainless Steel: Chandi Mohanty1; Xiaolei Guo1; Huseyin Kaya2; Stephane Gin3; Joseph Ryan4; John Vienna4; Seong Kim5; Jianwei Wang6; Jie Lian7; Gerald Frankel1; 1The Ohio State University; 2 The Pennsylvania State University; 3CEA; 4Pacific Northwest National Laboratory; 5The Pennsylvania State University; 6Louisiana State University; 7Rensselaer Polytechnic Institute
In the present study, interactive corrosion between International Simple Glass (ISG) and Stainless Steel 316 (SS) has been studied by exposing sandwiched coupons of these materials in different solutions at 90oC. Solution analyses and cross-section morphologies indicate a higher dissolution of ISG in the presence of SS. The chemical composition of the glass alteration layer depends on the local solution chemistry, which in turn is affected by the localized corrosion of SS. Infrared spectroscopy results indicate structural reorganization of the silicate alteration layer. On the other hand, localized corrosion of SS in contact with ISG is aggravated in the presence of Cl- in solution, which is known to be aggressive to corrosion resistant alloys. Metal cations from stainless steel dissolution precipitate with SiO2 from solution on the ISG and SS surface resulting in enhanced dissolution of ISG.
10:40 AM
Revisiting the Atomic Structure of Glassy Silica by Force-enhanced Atomic Refinement: Mathieu Bauchy1; 1University of California, Los Angeles
Despite the archetypical nature of glassy silica, its medium-range order structure (e.g., ring size distribution) remains only partially understood. Although MD simulations can offer a direct access to the glass structure, they are limited to high cooling rates—which is a key limitation since the medium-range order can be strongly influenced by the cooling rate. As an alternative route, reverse Monte Carlo simulations can be used to “invert” experimental data into 3D structures, but can yield fairly unrealistic structures that are thermodynamically unstable. Here, to overcome these limitations, we adopt force-enhanced atomic refinement—which simultaneously leverages the knowledge of experimental data and interatomic potential. We demonstrate that this method yields a silica structure that simultaneously exhibits higher thermodynamic stability and enhanced agreement with diffraction data as compared to those produced by MD and reverse Monte Carlo.