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Atomic layer deposition onto carbon fiber fabrics
Author(s) -
Militzer Christian,
Dill Pauline,
Goedel Werner A.
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15087
Subject(s) - coating , materials science , atomic layer deposition , thermogravimetric analysis , scanning electron microscope , layer (electronics) , composite material , oxidizing agent , aluminium , fiber , deposition (geology) , conformal coating , chemical engineering , chemistry , paleontology , organic chemistry , sediment , engineering , biology
Carbon fiber fabrics, consisting of interwoven bundles of 3000 single fibers, were coated with Al 2 O 3 using the atomic layer deposition ( ALD ) process, exposing the fabrics to alternating pulses of trimethyl aluminium and water vapors. The thickness and uniformity of the coatings were investigated using scanning electron microscopy ( SEM ) and thermogravimetric analysis ( TGA ). The obtained coatings were conformal, 84 ALD cycles gave rise to approximately 20‐nm‐thick coatings and 168 ALD cycles to approximately 40‐nm‐thick coatings. It was found, that a uniform coating can be obtained at a purge time of 40 seconds. Reducing purge times below 20 seconds gives rise to increased particle growth and thus the coating becomes inhomogeneous. Initially, the samples that were coated had a size of 2×10 cm (thickness 0.3 mm). The size of the fabric was subsequently increased up to 8×20 cm and a uniform coating of the same quality was obtained. By oxidizing the coated fabrics, fabrics composed of interwoven alumina microtubes were obtained. Infiltration of the microtubes with solutions of two distinguishable fluorescent dyes showed that interchange of the dyes between warp and weft microtubes occurs, but is absent at approximately 20% of the crossovers. Taking all our findings into account, we conclude that the majority of the fibers were separated from each other by the coating prior to the oxidation. This work demonstrates that ALD is a suitable method to produce thin, conformal coatings on the surface of carbon fiber fabrics.