• Proceedings of the Materials Research Society of Korea Conference
• /
• 2005.05a
• /
• pp.288-288
• /
• 2005

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2005.05a
• /
• pp.289-289
• /
• 2005

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2001.11a
• /
• pp.22-22
• /
• 2001

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2001.11a
• /
• pp.59-59
• /
• 2001

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2000.11a
• /
• pp.81-81
• /
• 2000

• Composites Research
• /
• v.25 no.3
• /
• pp.76-81
• /
• 2012

Atmospheric pressure plasma treatment on carbon nanotube (CNT) surfaces was performed to modify reinforcement effect and interfacial adhesion of carbon fiber reinforced CNT-phenolic composites. The surface changes occurring on CNT treated with plasma were analyzed by using Fourier transform infrared spectroscope (FT-IR). The significant improvement of wettability on CNT was confirmed by static contact angle test after plasma treatment. Such plasma treatment resulted in a decrease in the advancing contact angle from $118^{\circ}$ to $60^{\circ}$. The interfacial adhesion between carbon fiber and CNT-phenolic composites increased by plasma treatment based on apparent modulus test results during quasi-static tensile strength. Furthermore, the proposed database offers valuable knowledge for evaluating interfacial shear strength (IFSS).

• Journal of Power System Engineering
• /
• v.13 no.1
• /
• pp.65-71
• /
• 2009

To address the need for new intelligent sensing, this paper introduces nano sensors made of carbon nanotube (CNT) composites and presents their preliminary experiments. Having smart material properties such as piezoresistivity, chemical and bio selectivity, the nano composite can be used as smart electrodes of the nano sensors. The nano composite sensor can detect structural deterioration, chemical contamination and bio signal by means of its impedance measurement (resistance and capacitance). For a structural application, the change of impedance shows specific patterns depending on the structural deterioration and this characteristic is available for an in-situ multi-functional sensor, which can simultaneously detect multi symptoms of the structure. This study is anticipated to develop a new nano sensor detecting multiple symptoms in structural, chemical and bio applications with simple electric circuits.

• Applied Chemistry for Engineering
• /
• v.20 no.5
• /
• pp.493-499
• /
• 2009

The properties of polystyrene and styrenic copolymer nanocomposites containing carbon nanotubes (CNT) and nanoclays were studied. Polystyrene and styrenic copolymer containing styrene and vinylbenzyl trimethylammonium chloride (SVTAC) were synthesized by emulsion polymerization. Polystyrene/CNT/clay and SVTAC/CNT/clay nanocomposites with various concentrations of CNT and different types of clay were prepared via mixing of polystyrene emulsion and clay. SVTAC/CNT nanocomposites showed a better electrical conductivity than PS/CNT nanocomposites. Nanocomposites with more surfactant during polymerization showed a better electrical conductivity than the ones with less surfactant. These indicated the positive effect of comonomer and surfactant on the electrical conductivity. Transmission electron microscopy (TEM) was used to analyze the state of CNT dispersion. TEM results showed that CNT loading, comonomer composition and amount of surfactant affected the final dispersion of CNT in nanocomposites. In order to confirm the effects of CNT loading, comonomer composition and the amount of surfactant on the thermal and dynamic mechanical properties, DSC and DMA analyses were conducted.

• Polymer(Korea)
• /
• v.35 no.1
• /
• pp.60-65
• /
• 2011

In order to maximize the performance of polymer nano-composites, it is essential to understand an effect of a dispersion state on material properties as well as to achieve highly dispersed composites. In this work, a simple quantitative approach to evaluate the degree of dispersion was suggested for carbon nanotube (CNT) embedded polymer nano-composites. Through UV-visible spectroscopy analysis, the transmittance of nano-composites was measured at various dispersion states and it was found that the transmittance reduced as the dispersion state of CNT improved. Based on the results, an effective concentration factor for quantitative evaluation of dispersion state was introduced into the Beer-Lambert transmittance law. The proposed method and parameter to evaluate the degree of dispersion were verified by analyzing the transmittances at different dispersion states of CNT, concentrations of CNT and sample thicknesses.

• Composites Research
• /
• v.29 no.5
• /
• pp.306-314
• /
• 2016

In this study, to improve the thermal stabilities of the epoxy composite specimens in addition to the enhanced mechanical properties, those were reinforced with carbon nanotubes and micrometer-sized silica particles. To disperse the filler in matrix relatively simple physical process, specimens were fabricated using shear mixing and sonication. Tensile strength, coefficients of thermal expansion and thermal conductivity of the specimens were measured with varied contents of the two fillers. The mechanical and thermal properties were also discussed, and the experimental results of thermal expansion related to the thermal stability of the specimens were compared with those from several micromechanics models. The hybrid composites specimens incorporating 0.6 wt％ of carbon nanotubes and 50 wt％ of silica particles showed better mechanical properties than the others with increase in tensile strength up to 11％, with respect to those of the baseline specimens. As the silica contents were increased the thermal expansion was reduced down to 36%, and the thermal stability was improved with the decreased thermal deformation. Thermal conductivity of the epoxy composite specimens incorporating 50 wt％ of silica particles was enhanced, which demonstrate improvement of 72%. The mechanical and thermal properties of the hybrid composites specimens incorporating the two fillers were improved simultaneously.