Asset Details
Do you wish to reserve the book?
Towards a unifying mechanistic model for silicate glass corrosion
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
Towards a unifying mechanistic model for silicate glass corrosion
Do you wish to request the book?
Towards a unifying mechanistic model for silicate glass corrosion
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
Towards a unifying mechanistic model for silicate glass corrosion
2018
Overview
Borosilicate glasses are currently used for the immobilization of highly radioactive waste and are materials of choice for many biomedical and research industries. They are metastable materials that corrode in aqueous solutions, reflected by the formation of silica-rich surface alteration layers (SAL). Until now, there is no consensus in the scientific community about the reaction and transport mechanism(s) and the rate-limiting steps involved in the formation of SALs. Here we report the results of multi-isotope tracer (
2
H,
18
O,
10
B,
30
Si,
44
Ca) corrosion experiments that were performed with precorroded and pristine glass monoliths prepared from the six-component international simple glass and a quaternary aluminum borosilicate glass. Results of transmission electron microscopy and nanoscale analyses by secondary ion mass spectrometry reveal a nanometer-sharp interface between the SAL and the glass, where decoupling of isotope tracer occurs, while proton diffusion and ion exchange can be observed within the glass. We propose a unifying mechanistic model that accounts for all critical observations so far made on naturally and experimentally corroded glasses. It is based on an interface-coupled glass dissolution-silica precipitation reaction as the main SAL forming process. However, a diffusion-controlled ion exchange front may evolve in the glass ahead of the dissolution front if SAL formation at the reaction interface significantly slows down due to transport limitations.
Alteration layer formation: model me this
A unifying mechanistic model has been developed for silicate glass corrosion that can explain all critical observations made to-date. Borosilicate glasses are often used in biomedical devices and to store and dispose of radioactive waste. They decay in aqueous solution via the generation of a porous ‘surface alteration layer’ (SAL), the structure of which is different to the bulk. How the SAL forms is still not clear, however, an international team lead by Thorsten Geislern at the University of Bonn, Germany, has now used multi-isotope tracer experiments, to provide detailed insight into the distinct chemical and transport steps occurring during SAL formation. Their results suggest that an ‘interface-coupled dissolution-precipitation’ reaction is the main mechanism at play during SAL formation, but that, if slowed by transport limitations, it may be replaced by an ‘interdiffusion’ process.
Publisher
Nature Publishing Group UK,Nature Publishing Group
Subject
