A combination of a series of epoxy coatings filled with octadecylamine (ODA)-modified graphene oxide (mGO) or commercial exfoliated graphite nanoplatelets (xGnP) was developed to boost the anticorrosion performances of mild steel substrates in acidic and NaCl aqueous solutions. The xGnP and mGO were applied successfully as fillers for the preparation of layer by layer (LBL) xGnP or mGO/epoxy coatings, respectively, which were coated on the clean steel surfaces to form LBLassembled layers. The LBL-assembled xGnP or mGO/epoxy coating-coated steel substrates exhibit excellent anticorrosion performances. The corrosion potentials (Ecorr) of xGnP-1/xGnP-2/3 and mGO-1/mGO-2/3 display at − 193 and − 150 mV, respectively, while Ecorr of the bare steel shows at − 871 mV of immersion in the 3.5 wt% NaCl solution. The most positive Ecorr values are obtained for xGnP-1/2/3 (− 117 mV) and mGO-1/2/3 (− 66 mV), showing the best anticorrosion performances compared to the bare steel (− 404 mV) in 17 wt% HCl solution.

Thermal management is significant to maintain the reliability and durability of electronic devices. Heat can be dissipated using thermal interface materials (TIMs) comprised of thermally conductive polymers and fillers. Furthermore, it is important to enhance the thermal conductivity of TIMs through the formation of a heat transfer pathway. This paper reports a polymer composite containing vertically aligned electrochemically exfoliated graphite (EEG). We modify the EEG via edge selective oxidation to decorate the surface with iron oxides and enhance the dispersibility of EEG in polymer resin. During the heat treatment and curing process, a magnetic field is applied to the polymer composites to align the iron oxide decorated EEG. The resulting polymer composite containing 25 wt% of filler has a remarkable thermal conductivity of 1.10 W m− 1 K− 1 after magnetic orientation. These results demonstrate that TIM can be designed with a small amount of filler by magnetic alignment to form an efficient heat transfer pathway.

To enhance the thermal properties of epoxy composites, expanded graphite (EG) was oxyfluorinated and embedded into epoxy resin as a reinforcement. The maximum thermal conductivity was obtained for epoxy composites with oxyfluorinated EG, representing a 62% increase compared to that of neat epoxy. Additionally, the glass transition temperature (Tg) and integral procedural decomposition temperature of epoxy composites with oxyfluorinated EG show the increase of 6% (4.4 °C) and 106% (264 °C), respectively, which indicated the improvement in thermal stability. These results can be attributed to the interfacial interaction between epoxy and oxyfluorinated EG, which formed strong interfacial interactions between the epoxy resin and EG due to the presence of oxygen- and fluorine-containing functional groups in oxyfluorinated EG.

In this paper, the response of graphite/epoxy laminated composite beams subjected to impact loads without damage, is studied by the use of the developed finite element program. The modified Hertzian contact law considered elasto-plastic process is used to calculate the dynamic responses between the impactor and laminated target. Numerical results are presented to demonstrate the effects on the histories of contact force, deflection, damage energy, strain and stress through the thickness due to stacking sequence. In view of the kinetic energy response, [0/30/0/-30]2S laminate is faster than that of other two laminates due to its flexural stiffness. In special, the distribution of stress through the thickness shows nearly linear despite its discontinuity of stacking sequences for dynamic analysis unlike static analysis in a laminated composites.

In this work, the effect of co-carbon fillers on the electrical and mechanical properties of epoxy nanocomposites was investigated. The graphite nanosheets (GNs) and multi-walled carbon nanotubes (MWNTs) were used as co-carbon fillers. The results showed that the electrical conductivity of the epoxy nanocomposites showed a considerable increase upon an addition of MWNTs when GNs were fixed at 2 wt.%. This indicated that low content GNs formed the bulk conductive network and then MWNTs added were intercalated between the GN layers, resulted in the formation of additional conductive pathway. Furthermore, the flexural strength of the epoxy nanocomposites was enhanced with increasing the MWNT content. It was probably attributed to the flexible MWNTs compared with rigid GNs, resulted in the enhancement of the mechanical properties.

현재 복합재료 분야의 기술은 나날이 발전되어지고 있는 상황이다. 복합재료로 만드는 여러가지 산업 시설물과 생활용품등이 나오고 만들어지고 있는 실정이다. 그러나 아직까지도 토목분야에서는 옛날의 구시대적인 재료를 가지고 건물 및 교량을 만들고 있다. 여기에는 여러 가지 문제점이 있겠지만 그중 가장 크게 문제가 되는 것은 복합재료의 이론이 너무 복잡하여 건설구조에 대한 응용이 지연되고 있는 것이다. 복합재료가 건설분야에서 보다 광범위하게 이용되기 위해서는 일반기술자에게 너무 어려운 이론을 쉽게 하기 위한 연구와 실험을 통한 데이터의 축적이다. 따라서, 본 논문에서는 고급 복합재료인 탄소섬유(Graphite/Epoxy)의 휨 특성을 3점 휨 실험을 통하여 이론값과 실험값을 비교·분석하여 단면이 크기가 변하더라도 건설 기술자들이 쉽게 응용할 수 있도록 결과를 제공하였다.