This document summarizes research on functionalizing and grafting single-walled carbon nanotubes (SWCNTs) onto carbon fiber substrates. The researchers attempted to create SWCNTs using a CVD process with Co, Fe catalysts and acetylene gas at temperatures from 750-900°C. The SWCNTs were then dispersed in ethanol, water, and acetone via sonication and grafted onto carbon fibers. Fragmentation tests using acoustic emission and photoelasticity were performed on the grafted fibers embedded in elastic and brittle resins to analyze the mechanical effects of grafting. Initial results showed the best dispersion was achieved with ethanol after 90 minutes of sonication. Further experiments are planned to improve the dispersion method

1. Functionalization of SWCNTs and c.f.
Grafting procedure and mechanical
characterization
Καθηγητής Koς.Α.Παϊπέτης
Yπ.δι/κός Κ.Τσίρκα
Ιωάννινα , Μάϊος 2015

2. Cvd
Attemt to create single wall nanotubes
Catalyst Co,Fe
Gas acetylene
Temperature for 750 -800-850-900 °C
Time for 30-15-10 min
Substrate carbon fiber
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3. Functionalization-grafting

4. Dispersion processes
• Sonicated for 2 hours (0.5 cycles -0.2 amplitude %) in ethanol-water-acetone
(0,7 % w/v functionalized swcnts Tuball)
• Soaked via deep coating method for 30 minutes
• Removed fibers
• Air drying
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5. Experiments dispersion
1. The best results were acquired with ethanol ,where large aggregates strip-shaped
– no dissolution were present during the first 45 minutes of sonication. Whereas the
dispersion was successful after 90 mimutes.
good dispersion
without big aggregates
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6. 2. Acetone showed no dispersion, creation of aggregates and bubbles .
t soni solubility
3. Water on the other hand presented some kind of dilution but not satisfactory
enough.
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7. Monofilament manufactor
1. 60 °C curing for 2 hours A SYSTEM 4-=elastomeric
2. Cool down 25 °C
3. 120 °C post curing for 1h 30 min
4. Cool down 25 °C B SYSTEM 100 -12=brittle
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8. Fragmentation test with acoustic emission
• Thickness < 2 mm in the active length
• Distance sensors 35 mm
• Load cell 1 Klb
• Velocity: 0.1mm/min
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9. Fragmentation test with photoelasticity
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10. Results

11. Processing results
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• C.F = carbon fiber – neat
• G=grafted – with cnts
• A= 4 ppw resin : 1 ppw hardener
• B= 100 ppw resin : 12 ppw hardener

12. As received
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13. After corrections
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14.  Breakdown another 8 samples from each category for comparison
 Samples preparation for RAMAN
 Problems with dispersion – ethanol non repeatable optimization
under progress
 Analysis with SEM to calculate cnts % on fiber
 Fragmentation test -wait 30 minutes on drawing
Conclusions-Planning objectives
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