• Journal of Adhesion and Interface
• /
• v.14 no.2
• /
• pp.75-81
• /
• 2013

Epoxy matrix based composites were fabricated by adding SiC nano fillers. The interfacial properties of composites were varied with different shapes of SiC nano fillers. To investigate the shape effects on the interfacial properties, beta and whisker type SiC nano fillers were used for this evaluation. The dispersion states of nano SiC-epoxy nanocomposites were evaluated by capacitance measurements. FE-SEM was used to observe the fracture surface of different structures of SiC-epoxy nanocomposites and to investigate for reinforcement effect. Interfacial properties between carbon fiber and SiC-epoxy nanocomposites were also evaluated by ILSS (interlaminar shear strength) and IFSS (interfacial shear strength) tests. The interfacial adhesion of beta type nanocomposites was better than whisker type.

• Composites Research
• /
• v.19 no.3
• /
• pp.23-28
• /
• 2006

Carbon nanotubes reinforced copper matrix laminated nanocomposites were developed and the mechanical properties were evaluated by using micro-tensile testing system. Sandwich-type laminated structure constituted with carbon nanotube layers as a reinforcement and electroplated copper matrix were fabricated by a new processing approach based on selective dip-coating of carbon nanotubes. The mechanical properties of nanocomposites were improved due to an enhanced load sharing capacity of carbon nanotubes homogeneously distributed within the in-plane direction, as well as a bridging effect of carbon nanotubes along the out-of-plane direction between the upper and lower matrices. The universality of the layering approach is applicable to a wide range of functional materials, and here we demonstrate its potential use in reinforcing composite materials.

• Polymer(Korea)
• /
• v.25 no.3
• /
• pp.414-420
• /
• 2001

In this study, the effect of type of intercalant on properties of epoxy nanocomposites was investigated. Cetyltrimethylammoniumbromide (CTMA) as an alkylammonium salt and cetyltributylphosphoniumbromgide (CTBP) as an alkylphosphonium salt were used to modify sodium montmorillonite. In the case of using the CTMA as an intercalant, the long spacing of the silicate layer was about $18.8 {\AA}$. When CTBP was used, the long spacing of the silicate layer ( $23.8{\AA}$) was higher than that of CTMA. From these results, the characteristic length of the modified silicate was found to be significantly affected by the type of intercalant. We also noted that the thermal stability of modified MMT were affected by the type of intercalant, but in the epoxy nanocomposites prepared from the modified MMT, the thermal stability remains almost the same regardless of the type of intercalant. Tensile strength and elongation of epoxy nanocomposites prepared from MMT modified with CTBT were found to be higher than those of the epoxy nanocomposite prepare with WT modified with CTMA.

• Polymer(Korea)
• /
• v.35 no.5
• /
• pp.451-457
• /
• 2011

The effect of latex particle size on rheological and electrical properties of latex-blended polystyrene (PS)/multi-walled carbon nanotube (MWCNT) nanocomposites was investigated. Mono-dispersed PS particles synthesized either by emulsifier-free emulsion polymerization or by dispersion polymerization were mixed with MWCNTs under ultrasonication, and freeze-dried to prepare the nanocomposites. As the MWCNT content increased, storage modulus, complex viscosity and electrical conductivity were substantially increased. The increase of storage modulus and complex viscosity was higher for larger PS particles. The effect of particle size on electrical properties was different depending on MWCNT content. With lower MWCNT content, the nanocomposite prepared by smaller PS particles showed higher electrical conductivity, but the opposite result was given as the content increased.

• Polymer(Korea)
• /
• v.38 no.6
• /
• pp.767-773
• /
• 2014

Rheological and electrical properties of polystyrene (PS)/carbon nanotube (CNT) nanocomposites via coagulated precipitation were investigated. Chemical modification and surfactant wrapping of CNT to improve the dispersion of CNTs may reduce the intrinsic properties of pristine CNT. To avoid this problem, PS and CNTs were dissolved and dispersed in dimethylformamide and then PS/CNT nanocomposites were prepared by the coagulated precipitation of CNT-dispersed PS solution in water. The coagulated precipitation method was highly effective enhancing the electrical conductivity of nanocomposites. Furthermore, the effect of adding poly(styrene-co-divinylbenzene) crosslinked particles to PS matrix on the rheological and electrical properties was investigated. With the addition of the crosslinked particles, the electrical percolation threshold of CNT reduced to 0.25 wt% and electrical conductivity increased further. It is speculated that CNTs in the volume occupied by crosslinked particles helped electrical pathway formation.

• Polymer(Korea)
• /
• v.29 no.1
• /
• pp.32-35
• /
• 2005

In this paper, the carbon nanotubes (CNTs) were ozonized and the positive temperature coefficient (PTC) behaviors of CNTs-filled high-density polyethylene (HDPE) conductive composites were studied. The results of element analysis (EA) and FT-IR indicate that the oxygen-containing functional groups on the CNTs surfaces, such as O-H, C-O, and C＝O groups, were increased with the ozonization. Electrical resistivities of the CNTs/HDPE composites were measured by using a digital multimeter. The resistivity of the composites was increased abruptly near the crystalline melting temperature of the HDPE used as matrix, which could be attributed to the destruction of conductive network by the thermal expansion of HDPE. And, the PTC intensity of the CNTs/HDPE composites was increased with the increase of the ozone treatment time. It was probably due to the growing of maximum volume resistivity of the composites induced by the increased oxygen-containing functional groups in the CNTs surfaces.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.2
• /
• pp.139-145
• /
• 2016

In this study, the moisture related hygroscopic characteristics and mechanical properties of epoxy-clay nanocomposites were investigated by experiments as a function of the weight fraction of nanoclay. The hygroscopic and mechanical properties including the moisture saturation amount, moisture diffusivity, adhesive strength, and tensile properties were obtained by moisture absorption test and various tensile tests, respectively. Also, the molecular dynamics (MD) simulation was devised to study of hygroscopic characteristics of nanocomposites and the results were compared to experimental results as a function of the nanoclay content. It was demonstrated that the proposed MD simulation technique can be successfully used for the prediction of the effects of the nanoclay on the moisture diffusion characteristics.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.434-435
• /
• 2009

최근 바이오매스를 친환경 소재로 활용하기 위한 연구개발 및 응용연구가 세계적으로 활발하게 진행되고 있다. 바이오매스를 기반으로 한 대표적인 친환경 소재는 바이오복합재료로서 현재 자동차의 내 외장재료로 사용되고 있으며 응용분야가 전자재료, 포장재료 등으로 다양하게 확대되고 있다. 바이오매스는 이산화탄소 흡수원일 뿐만 아니라 바이오매스를 이용한 바이오복합재료는 경량재료로서 자동차에 사용될 때 연비향상에 의해 이산화탄소 저감에 크게 기여할 수 있다. 최근에는 바이오매스를 기반으로 하여 고강도 특성 등 기존재료에 비해 우수한 특성을 가지는 나노소재를 제조하고 이를 다양한 에너지소재로 활용하기 위한 연구도 활발하게 진행되고 있다. 본 논문에서는 바이오매스를 기반으로 한 친환경 소재로서 바이오매스를 기반으로 한 바이오복합재료 및 친환경 나노소재의 연구동향 및 응용분야에 대해 소개하고자 한다.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2006.11a
• /
• pp.10.1-10.1
• /
• 2006

• Composites Research
• /
• v.17 no.4
• /
• pp.47-52
• /
• 2004

This paper established the procedure to fabricate the MWNT/PMMA nanocomposite by using together with injection molding and film casting processes. The fabrication process made it possible for MWNTs to be well dispersed in the PMMA matrix and also it could maintain the well-dispersed state effectively. And the mechanical material properties and SEM images of the fractural surface were observed. Moreover, a surfactant was used to disperse MWNTs more effectively and mechanical material properties were also investigated.