Titre : |
Surfactant-free oil-in-oil emulsion-templating of polyimide aerogel foams |
Type de document : |
texte imprimé |
Auteurs : |
Erin Farrell, Auteur ; Sadhan C. Jana, Auteur |
Année de publication : |
2022 |
Article en page(s) : |
p. 427-441 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Aérogels Caractérisation Emulsions Emulsions -- Stabilité Gélification Matériaux mésoporeux Matériaux poreux Modèles mathématiques Mousse (chimie) Polyimides
|
Index. décimale : |
668.4 Plastiques, vinyles |
Résumé : |
A surfactant-free oil-in-oil emulsion-templating method is presented for fabrication of monolithic polyimide aerogel foams using monomer systems that produce fast sol–gel transition. An aerogel foam is a high porosity (∼90%) material with coexisting meso- and macropores inherent to aerogels with externally introduced micrometer size open cells (macrovoids) that are reminiscent of foams. The macrovoids are introduced in polyimide sol using surfactant-free emulsion-templating of droplets of an immiscible liquid that are stabilized against coalescence by fast sol–gel transition. Three immiscible liquids – cyclohexane, n-heptane, and silicone oil – are considered in this work for surfactant-free emulsion-templating. The aerogel foam monoliths, recovered by supercritical drying, exhibit smaller size macrovoids when n-heptane and cyclohexane are used as emulsion-templating liquid, while the overall porosity and the bulk density show weak dependence on the emulsion-templating liquid. |
Note de contenu : |
- EXPERIMENTAL SECTION : Materials - Characterization
- RESULTS AND DISCUSSION : Emulsion stability - Gel times - Aerogel foam materials - BET surface area - Macrovoid and pore architecture
- Table 1 : Lists several properties of the solvents used.
- Table 2 : Interfacial tension values without surfactant
- Table 3 : Mean, median, maximum, and minimum droplet diameter in surfactant-free emulsions in N,N-dimethylformamide
- Table 4 : Droplet distribution data and mean diameter in micrometer in each size range
- Table 5 : Emulsion separation times and creaming rates in polyimide so
- Table 6 : Bulk density, shrinkage, porosity, and percent pores in macro- and mesopore range of emulsion-templated polyimide aerogel foams
- Table 7 : BET surface area |
DOI : |
https://doi.org/10.1515/ipp-2022-4248 |
En ligne : |
https://drive.google.com/file/d/1_xRc5_bNKiT5U2NT_gxrCiSs-qCRpbw0/view?usp=shari [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37918 |
in INTERNATIONAL POLYMER PROCESSING > Vol. 37, N° 4 (2022) . - p. 427-441