In situ production of very low density microporous polymeric foams
| Autor: | John W. Falconer, Colin Horsfield, Wigen Nazarov |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Materials science
Scanning electron microscope Precipitation (chemistry) Surfaces and Interfaces Microporous material Condensed Matter Physics Surfaces Coatings and Films chemistry.chemical_compound Monomer chemistry Parylene Polymerization Polymer chemistry Ultraviolet light Composite material Shrinkage |
| Zdroj: | Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 13:1941-1944 |
| ISSN: | 1520-8559 0734-2101 |
| Popis: | Small, open‐ended, parylene microcylinders of 400 μm diameter, 700 μm length, and 10 μm wall thickness were filled with a solution of a polyfunctional monomer of low concentration. The solution was polymerised in situ with ultraviolet light to produce a gel. Precipitation of these gels in a nonsolvent and subsequent drying by means of a critical point drying apparatus produced microcylinders filled with a low density foam. Radiographic examination of the foam gave a density of the order of 2 mg cm−3, and scanning electron microscopy micrographs showed cell sizes of the order of 1 μm. No shrinkage of the foam was observed with cylinders of the dimensions given, but with larger cylinders of diameter and length of the order of 1000 μm, some axial shrinkage was observed which resulted in cylinders with slightly concave ends (of the order of 20 μm). |
| Databáze: | OpenAIRE |
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