Quantitative assessment of ceramic suspension stability using a LUMiSizer analytical centrifuge

Sokola, Patrik (author), Skalar, Tina (author), Šiler, Pavel (author), Blahut, Jan (author), Kalina, Michal (author), Veteška, Peter (author), Ptáček, Petr (author)

The stability of ceramic suspensions is a key factor in the preparation and shaping of ceramic bodies. The presented work offers an experimental determination of ceramics suspensions stability using the LUMiSizer analytical centrifuge, focusing on kinetic behaviour using transmission profiles and instability indexes. Multiple ceramic systems comprising corundum, metakaolin, and zirconia suspensions were experimentally examined under varying solid contents, dispersant dosages, and additive concentrations. Results showed that highly loaded corundum suspensions with dispersant (Dolapix CE64) achieved excellent stability, with an instability index below 0.05. Compared to classical sedimentation tests, which are time-consuming and not highly sensitive, LUMiSizer offers a suitable alternative by guaranteeing correct kinetic data and instability indexes indicating suspension behaviour using centrifugal force. Comparisons of the LUMiSizer results and data obtained using the modified Stokes law confirmed increased terminal velocities in experiments with metakaolin suspensions, indicating the sensitivity of the centrifuge to the effect of dispersion medium shape. The influence of porogen (waste coffee grounds) on the stability of corundum suspensions was also investigated, followed by slip casting to create and characterize a ceramic body, confirming the possibility of shaping based on stability results. Furthermore, instability indices are suggested as a rapid, quantitative method for comparing system stability and as an auxiliary criterion to the rheological measurements. Optimal dispersant concentration for zirconia-based photocurable suspensions was identified as 8.5 wt.%, which minimized viscosity and, at the same time, assured maximal kinetic stability. Integrating the LUMiSizer analytical centrifuge with standard methods, including sedimentation tests and rheological measurements, highlights its value as a powerful tool for characterizing and optimizing ceramic suspensions.

• Language: English
• Keywords: sedimentation, corundum, zirconia
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 18 str.
• Numbering: Vol. 8, iss. 3, art. 115
• PID: 20.500.12556/RUL-175437
• UDC: 620.1:549.517.1
• ISSN on article: 2571-6131
• DOI: 10.3390/ceramics8030115
• COBISS.SI-ID: 251901443
• Publication date in RUL: 27.10.2025

Record is a part of a journal

• Title: Ceramics
• Shortened title: Ceramics
• Publisher: MDPI
• ISSN: 2571-6131
• COBISS.SI-ID: 31835943

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: sedimentacija, korund, cirkonijev oksid

Projects

• Funder: Ministry of Education, Youth and Sports of the Czech Republic
• Project number: FCH-S-25-8836