Factors affecting the electrical conductivity of conducting polymers

Pooja,Kumar Anil,Prasher Parteek,Mudila Harish 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Metals had been significantly substituted by synthetic polymers in most of our daily requirements, thus relaxing our life. Out of many applied areas, synthetic polymers especially conducting polymers had shown their marked effect and potential. Batteries, pseudocapacitors, superconductors, etc. are the potential zones where conducting polymers are chiefly employed owing to their appreciable conductivity, cost efficiency, and corrosion inhibition nature. Apart from energy storage devices, these conducting polymers find their potential application in biosensors, lasers, corrosion inhibitors, electrostatic materials, conducting adhesives, electromagnetic interference shielding, and others. These all applications including energy storage are due to astonishing properties like high conductivity, flexibility, tuneability, easy processibility, chemical, thermal and mechanical stability, easy and enhanced charge transportation, lightweight, etc. Conducting polymers are extensively studied for their application in energy storage batteries, for which the material under investigation needs to be electrically conductive. However, the conducting nature of these specific conducting polymers is dependent on numerous factors. This review discussed the effect of certain potential factors such as polymerization techniques temperature, doping, bandgap, extended conjugation, solvent, etc. on the electrical/electrochemical conductivity of these conducting polymers. These all factors with their specific variations are found to have a noticeable consequence on the electrical conductivity of the investigated conducting polymer and hence on the energy storage carried by them. This review could be proved beneficial to the readers, who can judiciously implement the conclusions to their research related to conducting polymers and their composites for generating highly efficient energy storage systems.

Fluorene-based alternating polymers containing electron-withdrawing bithiazole units: Preparation and device applications

Lee, Jaemin,Jung, Byung-Jun,Lee, Sang Kyu,Lee, Jeong-Ik,Cho, Hoon-Je,Shim, Hong-Ku Wiley Subscription Services, Inc., A Wiley Company 2005 Journal of polymer science Part A, Polymer chemist Vol.43 No.9

<P>We report here the synthesis via Suzuki polymerization of two novel alternating polymers containing 9,9-dioctylfluorene and electron-withdrawing 4,4′-dihexyl-2,2′-bithiazole moieties, poly[(4,4′-dihexyl-2,2′-bithiazole-5,5′-diyl)-alt-(9,9-dioctylfluorene-2,7-diyl)] (PHBTzF) and poly[(5,5′-bis(2″-thienyl)-4,4′-dihexyl-2,2′-bithiazole-5″,5″-diyl)-alt-(9,9-dioctylfluorene-2,7-diyl)] (PTHBTzTF), and their application to electronic devices. The ultraviolet–visible absorption maxima of films of PHBTzF and PTHBTzTF were 413 and 471 nm, respectively, and the photoluminescence maxima were 513 and 590 nm, respectively. Cyclic voltammetry experiment showed an improvement in the n-doping stability of the polymers and a reduction of their lowest unoccupied molecular orbital energy levels as a result of bithiazole in the polymers' main chain. The highest occupied molecular orbital energy levels of the polymers were −5.85 eV for PHBTzF and −5.53 eV for PTHBTzTF. Conventional polymeric light-emitting-diode devices were fabricated in the ITO/PEDOT:PSS/polymer/Ca/Al configuration [where ITO is indium tin oxide and PEDOT:PSS is poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonic acid)] with the two polymers as emitting layers. The PHBTzF device exhibited a maximum luminance of 210 cd/m<SUP>2</SUP> and a turn-on voltage of 9.4 V, whereas the PTHBTzTF device exhibited a maximum luminance of 1840 cd/m<SUP>2</SUP> and a turn-on voltage of 5.4 V. In addition, a preliminary organic solar-cell device with the ITO/PEDOT:PSS/(PTHBTzTF + C<SUB>60</SUB>)/Ca/Al configuration (where C<SUB>60</SUB> is fullerene) was also fabricated. Under 100 mW/cm<SUP>2</SUP> of air mass 1.5 white-light illumination, the device produced an open-circuit voltage of 0.76 V and a short-circuit current of 1.70 mA/cm<SUP>2</SUP>. The fill factor of the device was 0.40, and the power conversion efficiency was 0.52%. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1845–1857, 2005</P> <B>Graphic Abstract</B> <P>Two novel alternating polymers based on fluorene and electron-withdrawing bithiazole, poly[(4,4′-dihexyl-2,2′-bithiazole-5,5′-diyl)-alt-(9,9-dioctylfluorene-2,7-diyl)] (PHBTzF) and poly[(5,5′-bis(2″-thienyl)-4,4′-dihexyl-2,2′-bithiazole-5″,5″-diyl)-alt-(9,9-dioctylfluorene-2,7-diyl)] (PTHBTzTF), were synthesized by Suzuki polymerization. The physical and optical properties of the polymers were carefully characterized. The addition of bithiazole to the polymers' main chain not only reduced the lowest unoccupied molecular orbital energy levels of the polymers but also improved their n-doping stability. Polymeric light-emitting-diode devices and organic solar-cell devices with the polymers as active layers showed the potential of these kinds of materials for use in organic electronic devices. <img src='wiley_img/0887624X-2005-43-9-POLA20659-gra001.gif' alt='wiley_img/0887624X-2005-43-9-POLA20659-gra001'> </P>

Fabrication of conductive overcoat layer based on hybrid composites to protect flat conductive films

이진근,조원석,조한결,김영노,이홍주,김중현 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Conductive polymers are attracting attention as promising next-generation materials due to their various advantages such as flexibility, transparency and price competitiveness. However, it has difficulty in practical application due to low physical stability such as heat resistance and water resistance. Therefore, we propose a method of overcoat a layer prepared by hybrid composites on a flat conductive film coated on a substrate to improve the physical stability of conductive polymer. This layer improves stability and hardness by forming a network structure through the combination of silane coupling agent and organic polymer. However, since this layer has an insulating property, it is impossible to move the current through the upper contact after application. Therefore, a small amount of conductive polymer PEDOT:PSS was added to provide conductivity. As a result, a flexible, transparent, conductive overcoat layer having high hardness and stability was manufactured.

Study on lowering the percolation threshold of carbon nanotube-filled conductive polypropylene composites

Park, Seung Bin,Lee, Moo Sung,Park, Min 한국탄소학회 2014 Carbon Letters Vol.15 No.2

Conductive polymer composites (CPCs) consist of a polymeric matrix and a conductive fil-er, for example, carbon black, carbon fibers,graphite or carbon nanotubes (CNTs). The criti-cal amount of the electrically conductive fillernecessary 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 conduc-tive-fillerpercolation-threshold as much as possible. In this study, we investigated the effect of polymer/conductive-fillerinteractions, as well as the processing and morphological devel-opment of low-percolation-threshold (Φc) 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 mix-ing methods and the other using immiscible polymer blends. Variants of the conductive PP composite filledwith MWCNT was prepared by dry mixing, melt mixing, mechanofusion, and compression molding. The percolation threshold (Φc) 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 perco-lation 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) (PVD, PP/PVDF, volume ratio 1:1) filled with MWCN.

전도성 고분자와 절연성 고분자의 특성 및 동향

장아영(Ayoung Jang),이지수(Jisu Lee),이상오(Sang Oh Lee),이재웅(Jaewoong Lee) 한국염색가공학회 2023 韓國染色加工學會誌 Vol.35 No.4

Conductive polymers are polymers that conduct electricity like metal conductors. Unlike typical organic polymers, they are polymers that have the electrical, magnetic, and optical properties of metals or semiconductors. For Example, these conductive polymers include Polypyrrole (PPy), Polyaniline (PANI), and Polythiophene (PT). On the other hand, Insulating polymers do not conduct electricity well while providing insulation, which is the opposite of conductivity. With the exception of conductive polymers, most polymers are non-conductors. Insulating polymers include polyimide (PI), polystyrene (PS), and poly(vinyl alcohol) (PVOH, PVA, or PVAl). Although many different polymers exist, we have simply illustrated the properties and recent developments of conductive and insulating polymers, which have opposite properties.

대두종자의 polymer coating 연구 1 : polymer coating 종자의 conductivity 차이

李成春,J. S. Burris 韓國作物學會 1994 Korean journal of crop science Vol.39 No.2

Polyme coating 종자의 환경적응성을 구명하기 위한 일환으로 콩 종자에 10종의 polymer를 coating하여 각 coating polymer별 conductivity, 발아력, 수분흡수력을 조사하였던 바 그 결과를 요약하면 다음과 같다. 1. Conductivity는 polymer coating한 종자가 coating하지 않은 종자보다 높았으며, 가장 높았던 polymer는 waterlock이었다. 2. Conductivity는 침종 후 시간이 경과할 수록 높아졌고, 100립중이 무거울 수록 높았다. 3. 수확년도가 오래된 종자의 conductivity가 당년에 수확한 종자보다도 높게 나타났다 4. 수분흡수 정도는 coating polymer에 따라 각각 달랐는데 daran 8600은 질이 떨어지는 종자에서는 수분흡수를 크게 저 해하였다. 5. Coating polymer 중 waterlock, captan, klucel, sacrust 등은 발아율을 상승시켰고, daran 8600은 발아율을 저하시켰으며 나머지 polymer는 품종에 따라 각각 달랐고 그 정도는 질이 떨어지는 종자에서 훨씬 컸다. 6. Polymer의 특성에 따라 수분흡수를 저해하거나 조장하였다. These experiment were conducted to evaluate the environmentally acceptable polymers, and 10 polymers were used in these study, and to investigate conductivity, germination percentage, water uptake of polymeric coating soybean seed. The conductivity of polymeric coating seed is higher than that of none coating seed and the highest conductivity was obtained with waterlock coating seed among the 10 polymer coating seed. As the soaking time was long, the conductivity was increased. The conductivity of large seed was higher than that of small seed, and that of long period storage seed was higher than that of short period storage seed. The effects of seed coating polymers on uptake water were various, and daran 8600 inhibited uptake water of low quality seed. The waterlock, captan, klucel and sacrust was rised germination percentage, and daran 8600 was declined germination percentage, and the effect of coating polymers on germination percentage of low quality seed was higher than that of high quality seed.

Conducting-Polymer Nanomaterials for High-Performance Sensor Applications: Issues and Challenges

Yoon, Hyeonseok,Jang, Jyongsik WILEY-VCH Verlag 2009 Advanced Functional Materials Vol.19 No.10

<P>Owing to their promising applications in electronic and optoelectronic devices, conducting polymers have been continuously studied during the past few decades. Nevertheless, only limited progress had been made in conducting-polymer-based sensors until nanostructured conducting polymers were demonstrated for high-performance signal transducers. Significant advances in the synthesis of conducting-polymer nanomaterials have been recently reported, with enhanced sensitivity relative to their bulk counterparts. Today, conducting-polymer nanomaterials rival metal and inorganic semiconductor nanomaterials in sensing capability. However, there are still several technological challenges to be solved for practical sensor applications of conducting-polymer nanomaterials. Here, the key issues on conducting-polymer nanomaterials in the development of state-of-the-art sensors are discussed. Furthermore, a perspective on next-generation sensor technology from a materials point of view is also given.</P> <B>Graphic Abstract</B> <P>The fascinating properties of conducting-polymer nanomaterials have inspired a worldwide effort in their application to state-of-the-art sensors (see image). Here, the important issues on conducting- polymer nanomaterials in sensor applications are discussed. Furthermore, a perspective on the next generation of sensor technology is provided. <img src='wiley_img/1616301X-2009-19-10-ADFM200801141-content.gif' alt='wiley_img/1616301X-2009-19-10-ADFM200801141-content'> </P>

열전도성 고분자 복합소재/금속 소재 하이브리드 구조의 방열기구 설계 및 방열특성에 관한 연구

유영은,김덕종,윤재성,박시환,Yoo, Yeong-Eun,Kim, Duck Jong,Yoon, Jae Sung,Park, Si-Hwan 한국금형공학회 2016 한국금형공학회지 Vol.10 No.3

Thermally or electrically conductive filler reinforced polymer composites are extensively being developed as the demand for light weight material increases rapidly in industiral applications need good conductivity such as heat sink of the electronics or light. Carbon or ceramic materials like graphite, carbon nanotube or boron nitride are typical conductive fillers with good thermal or electical conductivity. Using these conductive fillers, the polymer composites in the market show wide range of thermal conductivity from approximately 1 W/mK to 20 W/mK, which is quite enhanced considering the thermal conductivity lower than 0.5 W/mK for most polymeric materials. The practical use of these composites, however, is yet limited to specific applications because most composites are still not conductive enough or too difficult to process, too brittle, too expensive for higher conductivity. For practical use of conductive composite, the thermal conductivity required depending on the heat releasing mode are studied first for simplified unit cooling geometry to propose thermal conductivities of the composites for reasonable cooling performance comparing with the metal heat sink as a reference. Also, as a practical design for heat sink based on polymer composite, composite and metal sheet hybrid structures are investigated for LED lamp heat sink and audio amplication module housing to find that this hybrid structure can be a good solution considering all of the cooling performance, manufacturing, mechanical performance, cost and weight.

전도성 고분자가 첨가된 생체 모방형 분자 각인 고분자 테르펜 센서

정재훈 ( Jae Hun Jung ),이성필 ( Sung Pil Lee ) 한국센서학회 2012 센서학회지 Vol.21 No.5

Biomimetic terpene sensors which have high sensitivity and stability have been fabricated using moleculary imprinted polymer (MIP) technology, Since it is impossible to make a resistive type sensor due to the high resistance of MIP, we improved the sensor by adding conductive polymers. We investigated the sensitivity of resistive type sensors with nano particles depending on the amount of conductive polymers. The MIP membrane contained the methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross linker, which formed specific cavities originated by the target terpene molecules. The mixture of MIP and the conductive polymer was coated on the patterns of interdigit electrodes on the alumina substrate. The fabricated sensors showed their highest specific sensitivities exposed to 500ppm target gases: limonene 0.055 at 40% of amount of conductive polymers and geraniol 5.84ⅹ10-4 at 20% of amount of conductive polymers. In conclusion, we found that the terpene sensors are affected by the target molecules, functional monomers and the conductive polymers.

Roles of filler dimensions, interphase thickness, waviness, network fraction, and tunneling distance in tunneling conductivity of polymer CNT nanocomposites

Zare, Yasser,Garmabi, Hamid,Rhee, Kyong Yop Elsevier 2018 Materials chemistry and physics Vol.206 No.-

<P><B>Abstract</B></P> <P>We present a simple model to express the tunneling conductivity of polymer CNT nanocomposites as a function of the filler dimensions, filler conductivity, interphase thickness, waviness, fraction of networked CNTs, and tunneling distance. This model expresses the percolation threshold and the fraction of networked CNTs in terms of filler dimensions, waviness, and interphase thickness. The model was tested using experimental results from the literature. The predictions show good agreement with the experimental results in all samples, demonstrating the model's robustness for estimating tunneling conductivity. Moreover, the tunneling distance decreases as the filler concentration increases in all samples. The model parameters have a reasonable effect on the tunneling conductivity. The waviness and tunneling distance inversely affect the tunneling conductivity. Further, the waviness weakens the effective length of the nanotubes, and large tunneling distances cannot effectively transfer electrons between two adjacent nanotubes. The interphase thickness directly controls the tunneling conductivity, because a thick interphase reduces the percolation threshold. Poor percolation also creates large and dense conductive networks in nanocomposites, which is desirable for conductivity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A simple model for tunneling conductivity of polymer-CNT nanocomposites is suggested. </LI> <LI> Interphase thickness, fraction of networked CNTs, and tunneling distance are assumed. </LI> <LI> The model expresses the percolation threshold and the fraction of networked CNTs. </LI> <LI> The model is tested using experimental results from the literature and parametric analyses. </LI> <LI> The predictions show good agreement with the experimental results in all samples. </LI> </UL> </P>