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Multi-Functional Carbon Fibre Composites using Carbon Nanotubes as an Alternative to Polymer Sizing

View Article: PubMed Central - PubMed

ABSTRACT

Carbon fibre reinforced polymers (CFRP) were introduced to the aerospace, automobile and civil engineering industries for their high strength and low weight. A key feature of CFRP is the polymer sizing - a coating applied to the surface of the carbon fibres to assist handling, improve the interfacial adhesion between fibre and polymer matrix and allow this matrix to wet-out the carbon fibres. In this paper, we introduce an alternative material to the polymer sizing, namely carbon nanotubes (CNTs) on the carbon fibres, which in addition imparts electrical and thermal functionality. High quality CNTs are grown at a high density as a result of a 35 nm aluminium interlayer which has previously been shown to minimise diffusion of the catalyst in the carbon fibre substrate. A CNT modified-CFRP show 300%, 450% and 230% improvements in the electrical conductivity on the ‘surface’, ‘through-thickness’ and ‘volume’ directions, respectively. Furthermore, through-thickness thermal conductivity calculations reveal a 107% increase. These improvements suggest the potential of a direct replacement for lightning strike solutions and to enhance the efficiency of current de-icing solutions employed in the aerospace industry.

No MeSH data available.


Electrical conductivity results for CFRP and F-CFRP for the surface, thickness and volume directions.(Insets of (a) and (b)) Different configurations for the electrical conductivity test. The silver rectangles on the sample depict the silver DAG conductive paint. (a) Electrical conductivity results for all plies modified against unmodified composite. (b) Electrical conductivity tests of 4-ply (of 14) FF layers (termed (4 F)-CFRP). (c,d) Diagram of the hybrid (carbon fibre grey, left and fuzzy fibre black, right) test specimens with electrical conductivity results. Silver squares represent the silver DAG contact patches. (c) Comparison between CFRP (bold lines as benchmarks) and (1F)-CFRP (dashed lines). (d) Comparison between all measurements where the line thickness dictates the resistance (200:1).
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f3: Electrical conductivity results for CFRP and F-CFRP for the surface, thickness and volume directions.(Insets of (a) and (b)) Different configurations for the electrical conductivity test. The silver rectangles on the sample depict the silver DAG conductive paint. (a) Electrical conductivity results for all plies modified against unmodified composite. (b) Electrical conductivity tests of 4-ply (of 14) FF layers (termed (4 F)-CFRP). (c,d) Diagram of the hybrid (carbon fibre grey, left and fuzzy fibre black, right) test specimens with electrical conductivity results. Silver squares represent the silver DAG contact patches. (c) Comparison between CFRP (bold lines as benchmarks) and (1F)-CFRP (dashed lines). (d) Comparison between all measurements where the line thickness dictates the resistance (200:1).

Mentions: Electrical conductivity tests were conducted in the surface, through-thickness and volume directions and the results are displayed in Fig. 3. The figure shows strong improvements in the electrical conductivity in all directions after the addition of the CNTs. These are: 300% increase in the surface direction, 450% increase in the thickness direction and 230% increase in the volume direction for fuzzy CFRP (F-CFRP) compared to the standard CFRP. The improvement in the surface direction suggests the CNTs are bridging the insulating gap from the fibre to the electrical probe and/or utilising adjacent plies via CNTs to transport electrons. The greatest improvement is in the thickness direction, as the CNTs bridge the electrically insulating interlaminar regions and ply to electrical probes. This result is of key significance in developing the out-of-plane electrical properties of CFRP.


Multi-Functional Carbon Fibre Composites using Carbon Nanotubes as an Alternative to Polymer Sizing
Electrical conductivity results for CFRP and F-CFRP for the surface, thickness and volume directions.(Insets of (a) and (b)) Different configurations for the electrical conductivity test. The silver rectangles on the sample depict the silver DAG conductive paint. (a) Electrical conductivity results for all plies modified against unmodified composite. (b) Electrical conductivity tests of 4-ply (of 14) FF layers (termed (4 F)-CFRP). (c,d) Diagram of the hybrid (carbon fibre grey, left and fuzzy fibre black, right) test specimens with electrical conductivity results. Silver squares represent the silver DAG contact patches. (c) Comparison between CFRP (bold lines as benchmarks) and (1F)-CFRP (dashed lines). (d) Comparison between all measurements where the line thickness dictates the resistance (200:1).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC5120359&req=5

f3: Electrical conductivity results for CFRP and F-CFRP for the surface, thickness and volume directions.(Insets of (a) and (b)) Different configurations for the electrical conductivity test. The silver rectangles on the sample depict the silver DAG conductive paint. (a) Electrical conductivity results for all plies modified against unmodified composite. (b) Electrical conductivity tests of 4-ply (of 14) FF layers (termed (4 F)-CFRP). (c,d) Diagram of the hybrid (carbon fibre grey, left and fuzzy fibre black, right) test specimens with electrical conductivity results. Silver squares represent the silver DAG contact patches. (c) Comparison between CFRP (bold lines as benchmarks) and (1F)-CFRP (dashed lines). (d) Comparison between all measurements where the line thickness dictates the resistance (200:1).
Mentions: Electrical conductivity tests were conducted in the surface, through-thickness and volume directions and the results are displayed in Fig. 3. The figure shows strong improvements in the electrical conductivity in all directions after the addition of the CNTs. These are: 300% increase in the surface direction, 450% increase in the thickness direction and 230% increase in the volume direction for fuzzy CFRP (F-CFRP) compared to the standard CFRP. The improvement in the surface direction suggests the CNTs are bridging the insulating gap from the fibre to the electrical probe and/or utilising adjacent plies via CNTs to transport electrons. The greatest improvement is in the thickness direction, as the CNTs bridge the electrically insulating interlaminar regions and ply to electrical probes. This result is of key significance in developing the out-of-plane electrical properties of CFRP.

View Article: PubMed Central - PubMed

ABSTRACT

Carbon fibre reinforced polymers (CFRP) were introduced to the aerospace, automobile and civil engineering industries for their high strength and low weight. A key feature of CFRP is the polymer sizing - a coating applied to the surface of the carbon fibres to assist handling, improve the interfacial adhesion between fibre and polymer matrix and allow this matrix to wet-out the carbon fibres. In this paper, we introduce an alternative material to the polymer sizing, namely carbon nanotubes (CNTs) on the carbon fibres, which in addition imparts electrical and thermal functionality. High quality CNTs are grown at a high density as a result of a 35 nm aluminium interlayer which has previously been shown to minimise diffusion of the catalyst in the carbon fibre substrate. A CNT modified-CFRP show 300%, 450% and 230% improvements in the electrical conductivity on the ‘surface’, ‘through-thickness’ and ‘volume’ directions, respectively. Furthermore, through-thickness thermal conductivity calculations reveal a 107% increase. These improvements suggest the potential of a direct replacement for lightning strike solutions and to enhance the efficiency of current de-icing solutions employed in the aerospace industry.

No MeSH data available.