• Carbon letters
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• v.14 no.3
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• pp.190-192
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• 2013

It has been demonstrated in a previous study that carbon nanotube (CNT)/epoxy/basalt composites produce better flexural properties than epoxy/basalt composites. In this study, mode I fracture tests were conducted using CNT/epoxy/basalt composites with and without seawater absorption in order to investigate the effect of the seawater absorption on the mode I fracture toughness ($G_{Ic}$) of the CNT/epoxy/basalt composites. The results demonstrated that the compliance of the seawater-absorbed specimen was larger than that of the dry specimen at the same crack length, while the opposite result was obtained for the fracture load. The $G_{Ic}$ value of the seawater-absorbed CNT/epoxy/basalt composites was approximately 20% lower than that of the dry CNT/epoxy/basalt composites.

• Carbon letters
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• v.12 no.3
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• pp.177-179
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• 2011

The use of carbon nanotubes (CNTs) as a reinforcing material in a polymer matrix has increased in various industries. In this study, the flexural behavior of CNT-modified epoxy/basalt (CNT/epoxy/basalt) composites is investigated. The effects of CNT modification with silane on the flexural properties of CNT/epoxy/basalt composites were also examined. Flexural tests were performed using epoxy/basalt, oxidized CNT/epoxy/basalt, and silanized CNT/epoxy/basalt multi-scale composites. After the flexural tests, the fracture surfaces of the specimens were examined via scanning electron microscopy (SEM) to investigate the fracture mechanisms of the CNT/epoxy/basalt multi-scale composites with respect to the CNT modification process. The flexural properties of the epoxy/basalt composites were improved by the addition of CNTs. The flexural modulus and strength of the silane-treated CNT/epoxy/basalt multi-scale composites increased by approximately 54% and 34%, respectively, compared to those of epoxy/basalt composites. A SEM examination of the fracture surfaces revealed that the improvement in the flexural properties of the silane-treated CNT/epoxy/basalt multi-scale composites could be attributed to the improved dispersion of the CNTs in the epoxy.

• Carbon letters
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• v.13 no.3
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• pp.187-189
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• 2012

This study investigates the flexural properties of multi-walled carbon nanotube (MWCNT) reinforced basalt/epoxy composites under conditions with and without moisture absorption. The basalt/CNT/epoxy composites were fabricated using 1 wt% silanized MWCNTs and kept in seawater for over 4 months. The flexural properties of the moisture absorbed specimens were evaluated and compared with those of dry specimens. The flexural properties of basalt/CNT/epoxy composites were found to decrease with moisture absorption. The flexural strength and modulus of moisture absorbed specimens were 22% and 16% lower, respectively, than those of the dry specimen. Scanning electron microscope examination of the fracture surfaces revealed that the decreases of flexural properties in the moisture absorbed specimen were due to the weakening of interfacial bonding from swelling of the epoxy matrix.