From Pickering foams to porous carbonate materials: crack-free structuring in drying ceramics
| Autor: | M. Hristova, Ivan Lesov, Nikolai D. Denkov, Slavka Tcholakova, V. Goletto |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Crack free 0104 chemical sciences chemistry.chemical_compound Colloid Colloid and Surface Chemistry Rheology chemistry visual_art visual_art.visual_art_medium Carbonate Ceramic Composite material 0210 nano-technology Porosity Porous medium Shrinkage |
| Zdroj: | Colloids and Surfaces A: Physicochemical and Engineering Aspects. 552:142-152 |
| ISSN: | 0927-7757 |
| DOI: | 10.1016/j.colsurfa.2018.05.025 |
| Popis: | Particle-stabilized foams have attracted considerable research interest, due to their long term stability (months to years) and the possibility to use them as precursors for production of porous materials with hierarchical porosity. In our previous study [Lesov et al., J. Colloid Interface Sci. 504 (2017) 48–57] we clarified the role of the rheological properties of the foamed suspensions and the type of foam film stabilization in the production of porous silica materials with low mass density and excellent insulating properties. In the current study we extend our approach to prepare lightweight carbonate ceramics with controlled density, shrinkage and good mechanical properties. To prepare the wet foam precursors, we tested a series of eight anionic surfactants which were previously reported to provide sufficient hydrophobization of CaCO3 particles and long-term stability of the liquid foams. From those surfactants, the medium-chain fatty acids led to crack-free porous materials with superior mechanical strength, compared to the conventional surfactants. We study the reasons for the formation of cracks in drying Pickering foams and, on this basis, propose optimal conditions for obtaining dry porous carbonate materials with required porosity. Mechanistic explanations are proposed for the main observed effects. |
| Databáze: | OpenAIRE |
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