• Polymer(Korea)
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• v.25 no.2
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• pp.293-301
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• 2001

Electrically conductive carbon fiber/high density polyethylene (CF/HDPE) composite films were fabricated by new method, so called electron-ion technology (EIT) and the effects of CF epoxy sizing on the volumetric resistivity. tensile strength and interphase properties of the films were investigated. While epoxy sizing increased conductivity of composite films resulting from enhanced tunneling effect it reduced interphase adhesion between CF and HDPE because polar epoxy sizing and nonpolar HDPE are incompatible. Consequently epoxy sized CF(CF(S)) caused significant reduction in the volumetric resisitivity and tensile strength of composite films when compared with unsized CF(CF(U)). Epoxy sizing reduced nucleating efficiency of CF(S), therefore CF(S)/HDPE composite films showed nonuniform transcrystalline layer when compared with CF(U)/HDPE composite films.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.105-108
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• 2000

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.65-66
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• 2006

Solubility of single wall carbon nanotubes (SWNTs) has been determined in various dispersing media by using the solvent parameters such as Kamlet-Taft parameter and 3-dimensional parameters. Nitric acid-treated SWNTs exhibit significantly improved solubility in hydrogen bondable solvents as well as in solvent mixtures. The forming bucky gel with ionic liquid allows for the new group of dissolving solvent. The dissolution behavior of SWNTs provides a route for SWNT dispersion/exfoliation in preparing electrically conductive films such as transparent electrode.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.500-504
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• 2020

Heating films were prepared with composites of poly (methyl methacrylate) and conductive graphite. The as-prepared composite was deposited on a PET film and then fabricated using a bar coater to produce a film with uniform thickness. Copper electrodes were attached to both ends of the as-prepared film, and the heating characteristics of the film were analyzed while applying a DC voltage. The electrical conductivity and heating temperature of the heating films depended on the size, structure, content, and the dispersion characteristics of the graphite in the composite. The thermal energy was adjusted by controlling the electrical energy, based on the Joule heating theory. The electrical resistance of the film was altered in proportion to Ohm's law, and the heating temperature was changed according to the structure of the film (interelectrode spacing or electrode length) and the conductive graphite content. When the content of conductive graphite in the film increases, the electrical resistance decreases, and the heating temperature increases; however, there is no significant change above a certain content (50%).

• Polymer(Korea)
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• v.37 no.4
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• pp.513-517
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• 2013

A novel conductive composite thin film was prepared for the first time by hybridization between polybenzoxazine (PBZ) having high heat resistance property and conductive graphene. Mechanically robust conductive graphene/PBZ composite thin films could effectively be prepared by a simple thermal treatment, which simultaneously induces reduction of graphene oxide (GO) and crosslinking reaction of benzoxazine monomer. Graphene sheets seem to be uniformly dispersed up to 3 wt% graphene content in the composite thin film as shown in the results of chemical/crystal structural and morphological analyses. This efficient route for making graphene/PBZ composite thin film would provide simultaneous improvement of mechanical property as well as electrical conductivity.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.382.2-382.2
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• 2014

We explain a method to fabricate multi-layered transparent conductive films (TCF) using graphene oxide (GO), copper powder and polyurethane (PU) solution. The flexible graphene nanosheets (GNSs) serve as nanoscale connection between conductive copper nanoparticles (CuNps) and PU nanofibers, resulting in a highly flexible TCF. To fabricate conductive films with high transmittance, polyurethane (PU) nanofibers were used for a conductive network consisting of CuNps and GNSs (CuNps-GNSs). In this experiment, copper powder and graphene oxides were mixed in deionized water with the ultrasonication for 2 h. NaBH4 solution is used as a reduction agents of CuNps and GNSs (CuNps-GNSs) under a nitrogen atmosphere in the oil bath at 100% for 24 h to mixed. The purified and dispersed CuNp-GNS were obtained in deionized water, and diluted to a 10wt.% based on the contents of GNSs. Polyurethane (PU) nanofibers on a PET substrate were formed by electrospinning method. PET slides coated with the PU nanofibers were immersed into CuNp-GNS solution for several second, rinsed briefly in deionized water, and dried to obtain self-assembled CuNp-GNS/PU films. The morphology of the multi-layered films were characterized with a field emission scanning electron microscope (FE-SEM, Hitachi S-4700) and atomic force microscope (AFM, PSIA XE-100). The electrical property was analysed by the I-V measurement system and the optical property was measured by the UV/VIS spectroscopy.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.218-224
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• 2014

Biodegradable conductive composite films of polylactic acid(PLA) were prepared with various amounts of polyaniline(PAni) doped with dodecylbenzenesulphonic acid (DBSA) by solution blending technique to identify their mechanical and electric properties. 15 mol% of DBSA doped PAni was easily obtained by polymerizing of aniline in the presence of APS and DBSA in THF at $0^{\circ}C$. FE SEM characterization showed that PAni were well spread on the PLA domains. The tensile strength of composite film with 15 wt% of PAni was significantly decreased from $565.3kg_f/cm^2$ for PLA film itself to $309.7kg_f/cm^2$. Elongations of all PAni/PLA composite films were also decreased up to 3-6%. Electrical conductivity of $2.9{\times}10^{-3}$ S/cm could be achieved for the composite film containing 15 wt% of PAni-DBSA. Thermal stability of these composite films measured by thermogravimetric analysis(TGA) showed a slight decrease with the amount of PAni in PAni/PLA composite films at temperature lower than $300^{\circ}C$. However, the final weight of char was strongly depended with the amount of PAni in original composite films. Conclusively, PAni/PLA composite films containing more than a 15 wt% of PAni could be used for intercepting electromagnetic and preventing electrostatic applications.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.53-56
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• 1998

Polypyrrole (PPy) is regarded as one of the most Promising intrinsically or naturally conductive polymer for practical applications due to its relatively high electrical conductivity, environmental stability and low toxicity. The typical PPy, which is insoluble and infusible, exhibits poor processability and lacks essential mechanical properties. A number of papers have concerned the efforts to overcome these drawbacks. (omitted)

• Journal of Electrochemical Science and Technology
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• v.9 no.4
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• pp.301-307
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• 2018

The current study fabricated magnetic functional reduced graphene oxide (MFRGO) by relying on ${FeCl_4}^-$ magnetic anion confined to cationic 1-methyl imidazolium. Furthermore, for improving the electrochemical performance of conductive polymer, hybrid poly ortho aminophenol (POAP)/ MFRGO films have then been fabricated by POAP electropolymerization in the presence of MFRGO nanorods as active electrodes for electrochemical supercapacitors. Surface and electrochemical analyses have been used for characterization of MFRGO and POAP/ MFRGO composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Prepared composite film exhibited a significantly high specific capacity, high rate capability and excellent cycling stability (capacitance retention of ~91% even after 1000 cycles). These results suggest that electrosynthesized composite films are a promising electrode material for energy storage applications in high-performance pseudocapacitors.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2345-2351
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• 2012

Conductive honeycomb-patterned polystyrene (PS) thin films were prepared by the formation of a polyaniline (PANI) thin layer on the surface of the patterned PS thin films using simple one-step chemical oxidative polymerization of aniline. The in situ chemical oxidation polymerization of aniline hydrochloride solution on the patterned structure of the PS films was conducted in the presence of multiwalled carbon nanotubes (MWCNT) to prepare the PANI-MWCNT/PS composite film. The concentration (wt %) of MWCNT was varied in the range of 1%-3% by weight. The dependence of surface morphology of the PANI/PS and PANI-MWCNT/PS composite film to the polymerization time was observed by scanning electron microscopy. The room temperature DC conductivity was obtained by the four-probe technique. The conductivity of the PANI-MWCNT/PS composite film was affected both by the MWCNT concentration and polymerization time. In addition, DC electrical field was loaded during the oxidative polymerization to affect the distribution of the MWCNT included in the composite film, varying the loading voltage in the range of 0.1-3.0 V. The conductivity of the PANI-MWCNT/PS composite film was increased as loading voltage rose. However, this increase stops at a voltage higher than the critical value.