Use of a quartz crystal microbalance to investigate the mechanical stability of silica xerogel membranes for volatile iodine capture

There have been numerous studies on silica-based sorbents for the capture of radioiodine off-gassed during the processing of legacy waste or the reprocessing of nuclear waste. While studies investigate their iodine capture efficiency, only limited information about their mechanical applicability is found in the literature. This study investigates mechanical stability of silica-based adsorbents under the gas flow conditions to evaluate and quantify the effects of flow on the structural integrity of the tested materials. Silica-based xerogels, prepared through sol-gel processing using only tetraethoxysilane (TEOS), TEOS with oil as porogen, TEOS with bismuth nanoparticles, and TEOS with both. The technique subjected the adsorbents to a gas stream and used adhesive-coated quartz crystal, connected to a quartz crystal microbalance (QCM), to collect the particles lost by the adsorbents under flow. Collection of particles change the crystal's resonance, and the change is recorded on the QCM. The QCM data is analyzed to quantify the mass lost by the adsorbents. Adsorbents that did not contain bismuth failed under the flow as the QCM registered mass gains on the crystals, while the adsorbents with bismuth showed no failure. The results were supported by optical imaging that showed cracks on the failed surfaces. The technique used in this study showed encouraging results that validate the conceptualization of the technique as well as provide feedback for improvements to fine-tune technique for continued testing of new and existing materials.

Level thesis:degree_level

Master's Degree

Year dc:date.issued

2022

Author dc:creator

• Ali, Muhammad

Advisor dc:contributor.advisor

• Carlson, Krista

Committee members dc:contributor.committeemember

• Chidambaram, Dev
• Menezes, Pradeep L.

Handle dc:identifier.uri

http://hdl.handle.net/11714/8428

OAI identifier oai:identifier

oai:scholarwolf.unr.edu:11714/8428