• Carbon letters
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• v.15 no.2
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• pp.117-124
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• 2014

Conductive polymer composites (CPCs) consist of a polymeric matrix and a conductive filler, for example, carbon black, carbon fibers, graphite or carbon nanotubes (CNTs). The critical amount of the electrically conductive filler necessary to build up a continuous conductive network, and accordingly, to make the material conductive; is referred to as the percolation threshold. From technical and economical viewpoints, it is desirable to decrease the conductive-filler percolation-threshold as much as possible. In this study, we investigated the effect of polymer/conductive-filler interactions, as well as the processing and morphological development of low-percolation-threshold (${\Phi}c$) conductive-polymer composites. The aim of the study was to produce conductive composites containing less multi-walled CNTs (MWCNTs) than required for pure polypropylene (PP) through two approaches: one using various mixing methods and the other using immiscible polymer blends. Variants of the conductive PP composite filled with MWCNT was prepared by dry mixing, melt mixing, mechanofusion, and compression molding. The percolation threshold (${\Phi}c$) of the MWCNT-PP composites was most successfully lowered using the mechanofusion process than with any other mixing method (2-5 wt%). The mechanofusion process was found to enhance formation of a percolation network structure, and to ensure a more uniform state of dispersion in the CPCs. The immiscible-polymer blends were prepared by melt mixing (internal mixer) poly(vinylidene fluoride) (PVDF, PP/PVDF, volume ratio 1:1) filled with MWCNT.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.3
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• pp.125-133
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• 2002

In order to fabricate stable conductive polymer actuators which can be operated in air, conductivity and solidity of polymer electrolyte materials have been studied. It was found that Nafion+LiCl is appropriate material to be used for conductive polymer actuator. Using the Nafion+LiCl solid polymer electrolyte, single layer PPy actuators have been fabricated and their deflection was measured. Double layer PPy actuators make up for shortcoming of single layer PPy actuator and displacement and frequency response can be improved by fabrication of double layer PPy actuator. This kind of all-solid-polymer actuator can be used for practical applications.

• ETRI Journal
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• v.32 no.3
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• pp.414-421
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• 2010

The interconnection mechanisms of a smart anisotropic conductive adhesive (ACA) during processing have been characterized. For an understanding of chemorheological mechanisms between the fluxing polymer and solder powder, a thermal analysis as well as solder wetting and coalescence experiments were conducted. The compatibility between the viscosity of the fluxing polymer and melting temperature of solder was characterized to optimize the processing cycle. A fluxing agent was also used to remove the oxide layer performed on the surface of the solder. Based on these chemorheological phenomena of the fluxing polymer and solder, an optimum polymer system and its processing cycle were designed for high performance and reliability in an electrical interconnection system. In the present research, a bonding mechanism of the smart ACA with a polymer spacer ball to control the gap between both substrates is newly proposed and investigated. The solder powder was used as a conductive material instead of polymer-based spherical conductive particles in a conventional anisotropic conductive film.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.3
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• pp.203-214
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• 2022

Thermoelectric (TE) heating and cooling devices, which are able to directly convert thermal energy into electrical energy and vice versa, are effective and have exhibited a potential for energy harvesting. With the increasing consumer demands for various wearable electronics, organic-based TE composite materials offer a promise for the TE devices applications. Conductive polymers are widely used as flexible TE materials replacing inorganic materials due to their flexibility, low thermal conductivity, mechanical flexibility, ease of processing, and low cost. In this review, we briefly introduce the latest research trends in the flexible TE technology and provide a comprehensive summary of specific conductive polymer-based TE material fabrication technologies. We also summarize the manufacture for high-efficiency TE composites through the complexation of a conductive polymer matrix/inorganic TE filler. We believe that this review will inspire further research to improve the TE performance of conductive polymers.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.12
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• pp.698-704
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• 2000

Mechanical performances of beam shaped and bridge-shaped conductive polymer actuator have been measured and analyzed varying polymerization conditions and operating conditions such as applied current, polymerizing time, frequency of the current and kinds of electrolytes. For the application of conductive polymer actuator to micropump, the diaphragm structure has been fabricated, which is composed of polypyrrole, solid polymer electrolyte and parylene. Measured results how the possibility of the practical application of conductive polymer actuator.

• Korean Journal of Materials Research
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• v.30 no.7
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• pp.327-332
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• 2020

Laser induced surface activation (LISA) technology requires refined selection of process variables to fabricate conductive microcircuits on a general polymer material. Among the process variables, laser mode is one of the crucial factors to make a reliable conductor pattern. Here we compare the continuous wave (CW) laser mode with the pulse wave (PW) laser mode through determination of the surface roughness and circuit accuracy. In the CW laser mode, the surface roughness is pronounced during the implementation of the conductive circuit, which results in uneven plating. In the PW laser mode, the surface is relatively smooth and uniform, and the formed conductive circuit layer has few defects with excellent adhesion to the polymer material. As a result of a change of laser mode from CW to PW, the value of Ra of the polymer material decreases from 0.6 ㎛ to 0.2 ㎛; the value of Ra after the plating process decreases from 0.8 ㎛ to 0.4 ㎛, and a tight bonding force between the polymer source material and the conductive copper plating layer is achieved. In conclusion, this study shows that the PW laser process yields an excellent conductive circuit on a polymeric material.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.275-275
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• 2006

A series of organoboron polymer electrolytes were prepared and their ion conductive characteristics was investigated in detail. Alkylborane type polymer electrolytes prepared by hydroboration polymerization exhibited improve lithium transference number due to efficient anion trapping of alkylborane unit. A lithium borate type polymer/salt hybrid was also successfully prepared by dehydrocoupling polymerization of lithium mesitylhydrorate. Ionic conductivity of single ion conductive polymer/salt hybrid was further improved in the case of comb like polymer/boron stabilized imido anion hybrid prepared via polymer reaction of poly(organoboron halide) with hexylamine and PEO monomethylether and subsequent neutralization with lithium hydride.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.2.3-2.3
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• 2011

With increased interest in printed devices, various metal nano inks have been investigated as candidates materials for printed electrodes and wiring as well as conductive film substituting photo-lithography process. Recent advances in organic conductive polymer allow us to fabricate high performance printed device. Meanwhile, there was several attempts to fabricate conductive films by mixing conductive polymer with metal nano-particle or nano-wires. The presence of Ag nanowires in conductive polymer mixture have shown good potential in organic photovoltaic devices.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.51-56
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• 2004

Conductive polymer blends and composites are widely used for different safety application such as electrostatic charge dissipation(ESD), electromagnetic interference(EMI) shielding, electrostatic prevention and safety chemical sensor. In order to prepare a impedance-type humidity sensor that is durable at high humidities and high temperature, electically conductive polymer blends based on diallyldimethylammonium chloride(DADMAC) and epoxy were prepared in this study. The polymer blends type conductive ionomer exhibits reaction each other DADMAC and epoxy in FT-IR and DSC analysis. The blends material was traced by new peak at 1600cm-1 and appeard improvement of thermal resistance by melting point shift. Alumina substrate was deposited a pair of gold electrodes by screen printing. The blend material were spin-coated with a thin film type on the surface of alumina substrate. The polymer bleld type sensor exhibits a linear impedance increasing better than DADMAC coated humidity sensor. Also it shows good sensitivity, low hysteresis and durability against high humidity.

• Membrane Journal
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• v.22 no.1
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• pp.35-45
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• 2012

We prepared the highly ordered nano-wires of polypyrrole, polyaniline conductive polymers and polypyrrole/ polyaniline conductive copolymers by templating the anodic aluminum oxide (AAO) porous membrane, in which pore diameter was 20 nm, 100 nm and 200 nm. Those conductive polymers were grown from pore inner surface of AAO membrane forming hollow tubes and then wire structures were formed after 3 hour polymerization. By removing AAO membrane templates using sodium hydroxide solution, the conductive polymer nano-wires were successfully obtained, of which diameter and length were close to the ones of nano-pores in AAO membrane template. Crystallinity and thermal stability of the conductive polymer nano-wires were higher than irregular ones that prepared by solution polymerization. Furthermore, the electrical resistance of conductive polymer nano-wires were reduced by about 4~60% compared with that of the irregular polymers prepared by solution polymerization.