Tailoring alumina thin film properties using hydrophilic/hydrophobic copolymer additives
✍ Scribed by Isac, L. ;Duta, A. ;Purghel, E. ;Chitanu, G. C. ;Mitrea, S. ;Pelin, I.
- Book ID
- 105364915
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 324 KB
- Volume
- 205
- Category
- Article
- ISSN
- 0031-8965
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✦ Synopsis
Abstract
Thin films of alumina were deposited onto aluminium‐treated substrates by pneumatic spray pyrolysis at 250 °C. As precursors, solutions of AlCl~3~ dissolved in the mixture water:ethanol = 1:1 were used. As morphology controlling agents, maleic acid based copolymers (HFB/HFL) and/or acetylacetone were added in spraying solutions. The absorptance (α) and emittance (ϵ) values are those expected for alumina films, as possible matrix in a cermet, used as a solar‐thermal selective absorber. The films have amorphous–crystalline structure and porous morphology. The alumina film composition and crystallinity can be tailored by adding acetylacetone in the spraying solution, when predominantly amorphous structures are obtained. The addition of hydrophobic/hydrophilic copolymer in the precursor solution favours the obtaining of porous aggregates with large, open structures (3.5–4 μm). These porous morphologies are suitable for further infiltration of metallic particles, for preparation of alumina‐based cermets. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)