Mechanically strong ice-templated laponite/poly(vinyl alcohol) aerogels
| Autor: | Syed Qutubuddin, Saeed M. Alhassan, David A. Schiraldi |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
chemistry.chemical_classification
Shearing (physics) Vinyl alcohol Aqueous solution Materials science Mechanical Engineering Modulus Aerogel Polymer Condensed Matter Physics chemistry.chemical_compound Compressive strength chemistry Pulmonary surfactant Mechanics of Materials General Materials Science Composite material |
| Zdroj: | Materials Letters. 157:155-157 |
| ISSN: | 0167-577X |
| Popis: | We report on the formation of directionally frozen ice-templated aerogels consisting of laponite and poly(vinyl alcohol). At high laponite fractions, fragile aerogels were produced while at higher polymer fraction, more rigid aerogels were produced. The freezing process led to polymer shearing and associated decrease in aerogel density via a polymer chain relaxation process after freeze-drying. The modulus of these aerogels is maximized at a laponite fraction of 0.3 due to the structure, which is comprised of columns of semi-hexagonal cells with six fold symmetry and an excess of cross-layer bridges. Such unique structure is only driven by the presence of laponite and poly(vinyl alcohol) and not by other structural driving agents (e.g. surfactant or freezing rate). Compressive modulus as high as 12 MPa, with density of 0.07 g/cm 3 can be obtained via cryo-processing of aqueous laponite/poly(vinyl alcohol) dispersions. |
| Databáze: | OpenAIRE |
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