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>

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>

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.

전도성 고분자 물질이 결합된 하이브리드 커플러를 적용한 RF 가스 센서

이용주(Yong-Joo Lee),김병현(Byung-Hyun Kim),이희조(Hee-Jo Lee),홍윤석(Yunseog Hong),이승환(Seung Hwan Lee),최향희(Hyang Hee Choi),육종관(Jong-Gwan Yook) 한국전자파학회 2015 한국전자파학회논문지 Vol.26 No.1

본 논문에서는 2.4 GHz에서 동작하는 90° 하이브리드 커플러 구조에 전도성 고분자 화합물을 적용한 가스 센서를 제안하였다. 가스 센서에서 전도성 고분자 화합물(Conducting Polymer: CP)는 특정 가스를 검출하는 검출 물질로 사용되며, 특정 가스와 반응할 때 대개 물질의 일함수(work function)와 전도도(conductivity) 및 임피던스가 변하게 된다. 이러한 물성변화 특성의 근거로 마이크로파 대역에서 90° 하이브리드 커플러 구조에 전도성 고분자를 적용하여 가변 감쇄기 및 가변 위상 천이기 형태의 센서를 제작하였다. 본 연구에서 제안한 센서는 전도성 고분자 화합물의 높은 전도도를 이용하여 기존 전송선로의 일부를 전도성 고분자 물질로 대체하였다. 실험은 온도 28℃와 상대습도 85 % 환경에서 진행되었으며, 센서에 100 ppm 농도의 에탄올 가스를 노출시켰다. 그 결과, S21의 진폭 특성이 최대 0.13 dB 변하였고, ∠S21 = 360°를 만족하는 주파수가 2.875 MHz 이동한 것을 확인하였다. In this paper, a gas sensor using a modified 90° hybrid coupler structure with conducting polymer which operates at 2.4 GHz is represented. Conducting polymers are used to the gas sensing material in proposed sensors. The conducting polymer varies its electrical property, such as work function and conductivity corresponding to the certain gas. To verify this variation of electrical property of conducting polymer at microwave frequencies, the conducting polymer is incorporated with the 90° hybrid coupler structure, and this proposed sensor operates as reflection type variable attenuator and variable phase shifter. The conducting polymer is employed as impedence-variable transmission lines that cause a impedance mismatching between the general transmission line and conducting polymer. The experiment was conducted with 100 ppm ethanol gas at temperature of 28℃ and relative humidity of 85 %. As a result, the amplitude deviation of S21 is 0.13 dB and the frequency satisfying ∠S21 = 360° is shifted about 2.875 MHz.

Current Research on Conducting Polymer-Carbon Nanocomposites for Bioengineering Applications

( Seunghyeon Lee ),( Sang Kyu Lee ),( Daseul Jang ),( Bong Sup Shim ) 한국고무학회 2017 엘라스토머 및 콤포지트 Vol.52 No.1

Conducting polymers and carbon nanomaterials offer a wide range of applications because of their unique soft conducting properties. Specifically, these conducting polymer-carbon nanocomposites have recently been utilized in bioengineering applications, partly because of their improved biocompatibility compared to conventional conducting materials such as metals and ceramics. Based on the assumption that these composites offer an important application potential as functional materials for biomedical devices or even as biomaterials, this review surveys the recent research trends on conducting polymers-carbon nanocomposites, focusing on bioengineering applications such as polyaniline (PANI), poly(3,4-ethylenedioxythiophene) or PEDOT, polypyrrole (Ppy), and carbon nanotubes and graphene.

Preparation and Characteristics of Conducting Polymer-Coated MWCNTs as Electromagnetic Interference Shielding Materials

Yeon-Yi Kim,Ju-Mi Yun,Young-Seak Lee,Hyung-Il Kim 한국탄소학회 2011 Carbon Letters Vol.12 No.1

The conducting polymer-coated multi-walled carbon nanotubes (MWCNTs) were prepared by template polymerization of aniline and pyrrole on the surface of MWCNTs in order to develop the novel electromagnetic interference (EMI) shielding materials. The conducting polymer phases formed on the surface of MWCNTs were confirmed by field emission-scanning electron microscopy and field emission-transmission electron microscopy. Both permittivity and permeability were significantly improved for the conducting polymer-coated MWCNTs due to the intrinsic electrical properties of MWCNTs and the conducting properties of coated polymers. The electromagnetic waves were effectively absorbed based on the permittivity nature of conducting polymer and MWCNTs preventing the secondary interference from reflecting the electromagnetic waves. The highly improved EMI shielding efficiency was also obtained for the conducting polymer-coated MWCNTs showing the synergistic effects by combining MWCNTs and the conducting polymers.

Effects of covalent and ionic crosslinking agents on physical properties of conducting polymer aerogels

이영빈,김선주 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Recently, aerogels based on conducting polymers, for example polyaniline and PEDOT:PSS composites, have been attracted a great deal of attention because they are promising for various electronics and energy-related applications. There are however several challenges for the conducting polymer aerogels to be realized as a component in everyday applications. Among the challenges, the fragile nature of the aerogels has been the most critical issue. Here we present a simple way to get mechanically robust and densely packed conducting polymer aerogels. We have prepared the aerogels by the freeze-drying process after combining covalent and ionic crosslinkers to ensure its mechanical integrity. Electrical resistance and UV-vis spectroscopy show the aerogels are electrically conductive. Improved mechanical features have been inspected by compression test with force gauge measurement. We have also investigated the morphological features by using SEM imaging to explain the observed phenomena.

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.

Improved performance of dual-conducting polymer-coated sulfur composite with high sulfur utilization for lithium-sulfur batteries

Jeong, Tae-Gyung,Lee, Yoon-Sung,Cho, Byung Won,Kim, Yong-Tae,Jung, Hun-Gi,Chung, Kyung Yoon Elsevier 2018 Journal of Alloys and Compounds Vol.742 No.-

<P><B>Abstract</B></P> <P>This study is aimed at alleviating the inherent disadvantages of sulfur cathodes in lithium-sulfur (Li-S) batteries by encapsulating the sulfur particles with a dual (ionic and electronic)-conducting polymer via a simple, single-step procedure. Successful encapsulation by the polymer was confirmed by microscopic analyses. The encapsulated sulfur electrodes exhibit stable cycling performance and high sulfur utilization; in particular, the cell with 1 wt% dual conducting polymer-coated sulfur particles exhibit the best cycle performance with a discharge capacity of 1002 mAh g<SUP>−1</SUP> after 100 cycles at 0.2 C-rate. As opposed to various sulfur-carbon composites reported previously, our 1 wt% dual conducting polymer-coated sulfur composite achieves a very high loading level of 99%. This simple strategy of encapsulating sulfur particles with functional polymers could be a potential pathway toward the commercialization of Li-S batteries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sulfur particles in Li-S battery were coated by a dual-conducting polymer. </LI> <LI> Encapsulated electrodes show high cycle performance and sulfur utilization. </LI> <LI> Battery with 1 wt% polymer-coated sulfur electrode gives best cycle performance. </LI> <LI> This polymer coating method will aid the commercialization of Li-S batteries. </LI> </UL> </P>