Visible and near infrared light active photocatalysis based on conjugated polymers

THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2017 Journal of Industrial and Engineering Chemistry Vol.51 No.-

<P><B>Abstract</B></P> <P>Conjugated polymers have been used to produce solar energy conversion materials in photovoltaics due to their outstanding light harvesting properties and low-cost processing. However, their photocatalytic activity has only recently been highlighted with the preparation of robust, metal-free, and visible or near-infrared light active photocatalysts. This review describes why the study of photocatalysis based on conjugated polymers has become vivid these days in comparison to inorganic or metal-based photocatalysts, and further illustrates the developed technologies concerning exclusively conjugated polymers but also hybrid structures. The different forms of the conjugated polymer photocatalysts include linear, graphitic C,N-based, porous, nanostructured, and coordinated polymers or polymers with units made of small molecular dye structures. The hybrid systems contain combinations of conjugated polymers with graphene, metals, or metal oxides. A perspective on the challenges posed by the future exploration of photocatalysts based on conjugated polymers is also provided, covering the inherent instability issues of conjugated polymers during the harsh photocatalytic reaction conditions. This review aims to provide an insight for the utilization of conjugated polymers in the fields of photocatalysis, energy conversion, and environment-friendly applications of solar energy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Conjugated polymers are prominent metal-free photocatalysts. </LI> <LI> Conjugated polymers are promising for visible- and near infrared-active photocatalysis. </LI> <LI> Linear, graphitic, porous, nanostructured and coordinated polymers are described. </LI> <LI> Hybrid systems with nanocarbons, metals and metal oxides enhance photocatalytic activities. </LI> <LI> Inherent instability of conjugated polymer-based photocatalysts is also addressed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis and characterization of an ionic conjugated polymer: Poly[2-ethynyl-N-(2-thiophenecarbonyl) pyridinium chloride]

Gal, Yeong-Soon,Jin, Sung-Ho,Park, Jong-Wook,Lim, Kwon Taek Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of polymer science Part A, Polymer chemist Vol.47 No.22

<P>The activated polymerization of 2-ethynylpyridine by using 2-thiophenecarbonyl chloride yielded the corresponding conjugated ionic polymer, poly[2-ethynyl-N-(2-thiophenecarbonyl)pyridinium chloride] (PETCPC). The polymerization proceeded well to give high yield of polymer without any additional initiator or catalyst. The instrumental analysis data on polymer structure indicated that the present ionic polymer have a conjugated polymer backbone system having N-(2-thiophenecarbonyl)pyridinium chloride as substituents. The photoluminescence maximum peak of PETCPC was located at 573 nm, which corresponds to the photon energy of 2.16 eV. The aromatic functional substituents in the conjugated backbone system shift PL maximum values because it makes different molecule arrangement. The cyclovoltamograms of PETCPC exhibited the electrochemically stable window at −1.24 to 1.80 V region. It was found that the kinetics of the redox process of polymer might be controlled by the reactant diffusion process from the experiment of the oxidation current density of polymer versus the scan rate. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6153–6162, 2009</P> <B>Graphic Abstract</B> <P>The activated polymerization of 2-ethynylpyridine by using 2-thiophenecarbonyl chloride yielded the corresponding conjugated ionic polymer, poly[2-ethynyl-N-(2-thiophenecarbonyl)pyridinium chloride] (PETCPC). The instrumental analysis data on polymer structure indicated that the present ionic polymer have a conjugated polymer backbone system having N-(2-thiophenecarbonyl)pyridinium as substituents. The photoluminescence maximum peak of polymer was located at 573 nm, which corresponds to the photon energy of 2.16 eV. The cyclovoltamograms of polymer exhibited the electrochemically stable window at −1.24 to 1.80 V region. The kinetics of the redox process of polymer was found to be controlled by the reactant diffusion process from the experiment of the oxidation current density of polymer versus the scan rate. <img src='wiley_img/0887624X-2009-47-22-POLA23658-gra001.gif' alt='wiley_img/0887624X-2009-47-22-POLA23658-gra001'> </P>

Photostablity enhancement of conjugated polymer by preparing conjugated polymer nanoparticles

채정완,박주현 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Conjugated polymers have a high conductivity that comes from pi electron delocalization. However, they can be easily oxidized and lose their properties by oxygen in air. Therefore, the photostability enhancement of conjugated polymers is a significant issue in their applications. we prepared conjugated polymer nanoparticles assembled with phospholipids via forming phase separated films followed by shattering the films. The phospholipids are highly bound to the polymer through an alkyl chain between the polymer side chain and the lipid alkyltail. We investigated the effect of the alkyl tail length of the phospholipids on the photostability of nanoparticles of conjugated polymers.

Facilitating polymer conjugation via combination of RAFT polymerization and activated ester chemistry

Wiss, Kerstin T.,Theato, Patrick Wiley Subscription Services, Inc., A Wiley Company 2010 Journal of polymer science Part A, Polymer chemist Vol.48 No.21

<P>The synthesis of block copolymers via polymer conjugation of well-defined building blocks offers excellent control over the structures obtained, but often several coupling strategies need to be explored to find an efficient one depending on the building blocks. To facilitate the synthesis of polymers with adjustable functional end-groups for polymer conjugation, we report on the combination of activated ester chemistry with RAFT polymerization using a chain transfer agent (CTA) with a pentafluorophenyl ester (PFP-CTA), which allows for flexible functionalization of either the CTA prior to polymerization or the obtained polymer after polymerization. Different polymethacrylates, namely PMMA, P(t-BuMA) and PDEGMEMA, were synthesized with an alkyne-CTA obtained from the aminolysis of the PFP-CTA with propargylamine, and the successful incorporation of the alkyne moiety could be shown via <SUP>1</SUP>H and <SUP>13</SUP>C NMR spectroscopy and MALDI TOF MS. Further, the reactive α-end-groups of polymers synthesized using the unmodified PFP-CTA could be converted into azide and alkyne end-groups after polymerization, and the high functionalization efficiencies could be demonstrated via successful coupling of the resulting polymers via CuAAC. Thus, the PFP-CTA allows for high combinatory flexibility in polymer synthesis facilitating polymer conjugation as useful method for the synthesis of block copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010</P> <B>Graphic Abstract</B> <P>This article demonstrates how a chain transfer agent (CTA) with an activated ester group enables the synthesis of well-defined polymers with diverse functional α-end-groups via two easy but very efficient methods, one being the synthesis of functional CTAs and the other being the conversion of the activated ester end-group after polymerization. High functionalization efficiencies could be obtained in the conversion of the activated ester into alkyne and azide groups, and the resulting polymers could be conjugated to each other successfully via CuAAC. Thus, this CTA allows for high combinatory flexibility in polymer synthesis via RAFT polymerization facilitating polymer conjugation. <img src='wiley_img_2010/0887624X-2010-48-21-POLA24267-gra001.gif' alt='wiley_img_2010/0887624X-2010-48-21-POLA24267-gra001'> </P>

2-브로모에틸 에틸 에테르를 이용한 2-에티닐피리딘의 중합을 통한 이온형 공액구조 고분자

갈영순 ( Yeong-soon Gal ) 한국화상학회 2020 한국화상학회지 Vol.26 No.2

2-브로모에틸 에틸 에테르를 이용한 2-에티닐피리딘의 무촉매 중합을 통하여 측쇄에 에테르 부분을 갖는 새로운 공액구조 고분자를 합성하였다. 이 중합반응은 비교적 낮은 온도 조건에서도 균일하게 잘 진행 되었으며 89%의 수율로 해당 고분자를 합성할 수 있었다. NMR, IR, UV-visible 분광분석기 등을 이용하여 고 분자의 구조를 분석한 결과 설계한 치환기를 갖는 해당 고분자가 합성되었음을 확인할 수 있었다. 본 고분자는 물을 포함한 DMF, DMSO, DMAc, 메탄올 등의 유기 용매에 완전히 용해하였다. 합성 고분자의 전기화학적 특성과 광발광 특성을 측정하고 분석하였다. A new ionic conjugated polymer with side-chain ether moieties was synthesized by the catalyst-freee polymerization of 2-ethynylpyridine using 2-bromoethyl ethyl ether. The polymerization proceeded easily in relatively mild reaction condition to yield 89% of polymer. The polymer structure was characterized by various instrumental methods such as NMR, IR, and UV-visible spectroscopies to have a conjugated backbone system with the designed substituents. This polymer was completely soluble in water and polar organic solvents such as DMF, DMSO, DMAc, and methanol. The electrochemical and electro-optical properties of the resulting polymer were measured and discussed.

Synthesis of BDP based conjugated polymer for polymer solar cells

전성재,이태호,한재필,허정림,문두경 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Polymer solar cells(PSCs), generally based on the bulk-heterojunction (BHJ) concept, have attracted tremendous attention due to their unique advantages including low cost, light weight, and potential applications in flexible and large-area devices. The benzo[1,2-b:4,5-b’]dithiophene (BDT) is another well used donor unit in high performance polymers at present. Because it have many advantages which are broad π-conjugation length, low HOMO level and high charge carrier mobility. To have a BDT's advantages and additional properties, we synthesized a structural isomer of BDT that is a benzo[2,1-b;3,4-b']dithiophene(BDP). The BDP has a improved planarity with a fused aromatic structures. It helps to form highly ordered films that facilitate charge-carrier transport. For that reasons, we introduced BDP derivative as a donor material and synthesized conjugated polymer via Stille coupling reaction. The synthesized polymer showed different properties compared with BDT based polymer. To demonstrate this effects, the polymer was characterized optical, electrochemical and photovoltaic properties, respectively.

Nanowires of amorphous conjugated polymers prepared via a surfactant-templating process using an alkylbenzoic acid

Bae, Naraechan,Park, Haneum,Yoo, Pil J.,Shin, Tae Joo,Park, Juhyun THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2017 Journal of Industrial and Engineering Chemistry Vol.51 No.-

<P><B>Abstract</B></P> <P>Conjugated polymer nanowires have recently attracted attention as new organic photocatalysts with improved photoexcited charge-carrier lifetime capable of efficient energy harvesting from sunlight. However, most methods to prepare the nanowires have focused on crystalline conjugated polymers, thereby limiting the number of usable polymer structures. In this study, we present a method for preparing nanowires of amorphous conjugated polymers to expand their applicability as photocatalysis. We demonstrate a nanowire fabrication process that utilizes an alkylbenzoic acid. At a specific concentration, the amphiphilic alkylbenzoic acid forms wire morphologies when its organic solution is added to an aqueous solution, partitioning the organic solution inside the wires and the outside aqueous solution. When the amorphous conjugated polymer in the organic solution is added, the conjugated polymers are located in the wires and form conjugated polymer nanowires upon removal of the organic solvent.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Octylbenzoic acid in chloroform forms nanowire emulsions in an aqueous medium. </LI> <LI> Well-ordered nanowire assemblies are formed upon removing chloroform. </LI> <LI> Mesogenic benzoic acid and alkyl tails form ordered nanowire assemblies. </LI> <LI> Alkyl chain association contributes to assemblies of OBA and PCPDTBT. </LI> <LI> Surfactant-templating produces nanowires of amorphous conjugated polymers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The Effect of Fluorine Substitution on the Molecular Interactions and Performance in Polymer Solar Cells

Kim, In-Bok,Jang, Soo-Young,Kim, Yeong-A,Kang, Rira,Kim, In-Sik,Ko, Do-Kyeong,Kim, Dong-Yu American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.28

<P>Fluorine (F) substitution on conjugated polymers in polymer solar cells (PSCs) has a diverse effect on molecular properties and device performance. We present a series of three D-A type conjugated polymers (PBT, PFBT, and PDFBT) based on dithienothiophene and benzothiacliazole units with different numbers of F atoms to explain the influence of F substitution by comparing the molecular interactions of the polymers and the recombination kinetics in PSCs. The preaggregation behavior of PFBT and PDFBT in o-DCB at the UV-vis absorption spectra proves that both polymers have strong intermolecular interactions. Besides, more closely packed structures and change into face-on orientation of fluorinated polymers are observed in polymer:PC71BM blends by GIRD which is beneficial for charge transport and, ultimately, for current density in PSCs (4.3, 13.0, and 14.5 mA cm(-2) for PBT, PFBT, and PDFBT, respectively). Also, the introduction of F atoms on conjugated backbones affects the recombination kinetics by suppressing bimolecular recombination, thereby improving the fill factor (0.41, 0.68, and 0.69 for PBT, PFBT, and PDFBT, respectively). Consequently, the PCE of PSCs reached 7.3% without, any additional treatment (annealing, solvent additive, etc.) in the polymer containing difluorinated BT (PDFBT) that is much higher than nonfluorinated BT (PBT similar to 1%) and monofluorinated BT (PFBT similar to 6%).</P>

D–A copolymer with high ambipolar mobilities based on dithienothiophene and diketopyrrolopyrrole for polymer solar cells and organic field-effect transistors

Kim, In-Bok,Khim, Dongyoon,Jang, Soo-Young,Kim, Jihong,Yu, Byung-kwan,Kim, Yeong-A,Kim, Dong-Yu Elsevier 2015 ORGANIC ELECTRONICS Vol.26 No.-

<P><B>Abstract</B></P> <P>Donor–acceptor (D–A) type conjugated polymers have been developed to absorb longer wavelength light in polymer solar cells (PSCs) and to achieve a high charge carrier mobility in organic field-effect transistors (OFETs). PDTDP, containing dithienothiophene (DTT) as the electron donor and diketopyrrolopyrrole (DPP) as the electron acceptor, was synthesized by stille polycondensation in order to achieve the advantages of D–A type conjugated polymers. The polymer showed optical band gaps of 1.44 and 1.42eV in solution and in film, respectively, and a HOMO level of 5.09eV. PDTDP and PC<SUB>71</SUB>BM blends with 1,8-diiodooctane (DIO) exhibited improved performance in PSCs with a power conversion efficiency (PCE) of 4.45% under AM 1.5G irradiation. By investigating transmission electron microscopy (TEM), atomic force microscopy (AFM), and the light intensity dependence of <I>J</I> <SUB>SC</SUB> and <I>V</I> <SUB>OC</SUB>, we conclude that DIO acts as a processing additive that helps to form a nanoscale phase separation between donor and acceptor, resulting in an enhancement of <I>μ</I> <SUB>h</SUB> and <I>μ</I> <SUB>e</SUB>, which affects the <I>J</I> <SUB>SC</SUB>, EQE, and PCE of PSCs. The charge carrier mobilities of PDTDP in OFETs were also investigated at various annealing temperatures and the polymer exhibited the highest hole and electron mobilities of 2.53cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> at 250°C and 0.36cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> at 310°C, respectively. XRD and AFM results demonstrated that the thermal annealing temperature had a critical effect on the changes in the crystallinity and morphology of the polymer. The low-voltage device was fabricated using high-<I>k</I> dielectric, P(VDF-TrFE) and P(VDF-TrFE-CTFE), and the carrier mobility of PDTDP was reached 0.1cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> at <I>V</I> <SUB>d</SUB> =−5V. PDTDP complementary inverters were fabricated, and the high ambipolar characteristics of the polymer resulted in an output voltage gain of more than 25.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We describe the synthesis and characterizations for donor–acceptor copolymer, PDTDP. </LI> <LI> PDTDP shows high crystallinity and appropriate energy levels for ambipolar OFETs. </LI> <LI> We achieved a 4.45% efficiency with processing additive, DIO, in PSCs. </LI> <LI> We achieve ambipolar field effect mobilities, <I>μ</I> <SUB>h</SUB> ∼2.53 and <I>μ</I> <SUB>e</SUB> ∼0.36cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Size and shape controlled synthesis of binapthyl-based conjugated polymer/gold nanoparticle nanocomposites

송선구,안종호,송창식,( T. Premkumar ) 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Binapthyl-based conjugated polymers/gold nanoparticle (AuNP) hybrid nanocomposites were in-situ synthesized by the oxidation of polymer with auric acid. Bithiophene groups in the polymer reduced the Au(III) into Au(0) and the AuNPs can be stabilized by the polymer, especially through binapthyl groups of tweezer-like structure. The hydrodynamic radius of the polymer affects the size and shape of polymer/AuNPs hybrid nanocomposites. We investigated the polymer/AuNPs hybrid nanocomposites changing the molecular weight and hydrodynamic radi of the polymers in different solvent. The synthesized polymer/AuNPs hybrid nanocomposites were analysized by scanning electron microscope (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), cyclic voltammetry (CV), and UV-vis spectroscopy. The polymers that have large hydrodynamic radii in solution formed large, multipod-like AuNPs structures and those with small hydrodynamic radii formed small, sphere-like AuNPs.