Design of alumina monoliths by emulsion-gel casting: Understanding the monolith structure from a rheological approach

Nayan Nayak, Nuno Vitorino, Jorge R. Frade, Andrei V. Kovalevsky, Vitor D. Alves, João G. Crespo, Carla A.M. Portugal

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)

Abstract

Multimodal porous cellular alumina structures (monoliths) were prepared by an emulsion-gel casting technique using eco-friendly and inexpensive lipids such as corn oil, castor oil, margarine and their mixtures as the dispersed phase. The monoliths obtained showed good mechanical stability, exhibiting compressive strengths in the range of 8–50 N·mm−2. Mercury intrusion porosimetry analysis showed that the monoliths produced presented porosities ranging from 28% to 60% and average pore sizes within 0.2–3.2 μm. The formation of the porous networks was interpreted based on combined droplet coalescence, flocculation and Ostwald ripening effects. The presence of such effects along the emulsion storage time led to changes in their viscoelastic and morphological properties, which were found to correlate with structural descriptors of monoliths after sintering (e.g. average pore sizes and porosity). These correlations open up the possibility to anticipate the final structure of the monoliths and adjust emulsion-gel conditions to produce customized cellular structures with fine-tuned porosities and pore sizes, envisaging their application in membrane processes or chromatography.

Original languageEnglish
Pages (from-to)119-129
Number of pages11
JournalMaterials and Design
Volume157
DOIs
Publication statusPublished - 5 Nov 2018

Keywords

  • Alumina monoliths
  • Chromatography
  • Emulsion-gel casting
  • Porous structure
  • Viscoelastic properties

Fingerprint

Dive into the research topics of 'Design of alumina monoliths by emulsion-gel casting: Understanding the monolith structure from a rheological approach'. Together they form a unique fingerprint.

Cite this