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Journal articles on the topic 'HOMO POLYMER'

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Author: Grafiati
Published: 11 September 2023

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1

Orlova, M., S. Didenko, D. Saranin, O. Rabinovich, A. Panichkin, and I. Borzykh. "New Polymer Systems for Use in Organic Photovoltaics." International Journal of Nanoscience 17, no. 05 (October 2018): 1750022. http://dx.doi.org/10.1142/s0219581x17500223.

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In this paper, new polymers for use in organic photovoltaics were investigated. PPBI, PNBI and copolymer MULT are considered as a potential alternative or an effective dopant for P3HT and PCBM. The choice of these materials allows us to find out new information on the prospects and properties of heterocyclic polymers — for thermal stability and resistance to the environment for organic solar cells. The levels of HOMO and LUMO of new heterocyclic polymers were measured, and the results were compared with those of P3HT: PCBM. The level of new polymer MULT photoluminescence was determined. The absorption blend for P3HT: PCBM peak absorption shift was detected by adding 5% (by mass) of the new polymer MULT, the value of 30–40[Formula: see text]nm to longer wavelengths. Data obtained by cyclic voltammetry showed deep HOMO levels of heterocyclic polymers in values of about [Formula: see text]6[Formula: see text]eV, which is promising in terms of acceptor properties.
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2

Wu, Haimei, Baofeng Zhao, Weiping Wang, Zhaoqi Guo, Wei Wei, Zhongwei An, Chao Gao, et al. "Side chain modification: an effective approach to modulate the energy level of benzodithiophene based polymers for high-performance solar cells." Journal of Materials Chemistry A 3, no. 35 (2015): 18115–26. http://dx.doi.org/10.1039/c5ta05096k.

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Over the past few years, it has been proven that deepening the highest occupied molecular orbital (HOMO) levels of conjugated polymers is one of the most successful strategies to develop novel materials for high performance bulk heterojunction polymer solar cells.
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3

Viswanathan, Vinila N., Arun D. Rao, Upendra K. Pandey, Arul Varman Kesavan, and Praveen C. Ramamurthy. "Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications." Beilstein Journal of Organic Chemistry 13 (May 10, 2017): 863–73. http://dx.doi.org/10.3762/bjoc.13.87.

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A series of low band gap, planar conjugated polymers, P1 (PFDTBT), P2 (PFDTDFBT) and P3 (PFDTTBT), based on fluorene and benzothiadiazole, was synthesized. The effect of fluorine substitution and fused aromatic spacers on the optoelectronic and photovoltaic performance was studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1, exhibited a highest occupied molecular orbital (HOMO) energy level at −5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine, both the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels of the resulting polymer, P2, were lowered, leading to a higher open circuit voltage and short circuit current with an overall improvement of more than 110% for the photovoltaic devices. Moreover, a decrease in the torsion angle between the units was also observed for the fluorinated polymer P2 due to the enhanced electrostatic interaction between the fluorine substituents and sulfur atoms, leading to a high hole mobility. The use of a fused π-bridge in polymer P3 for the enhancement of the planarity as compared to the P1 backbone was also studied. This enhanced planarity led to the highest observed mobility among the reported three polymers as well as to an improvement in the device efficiency by more than 40% for P3.
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4

Tsai, Huai-Wen, Kan-Lin Hsueh, Mei-Hsin Chen, and Che-Wun Hong. "Electronic and Optical Properties of Polythiophene Molecules and Derivatives." Crystals 11, no. 11 (October 25, 2021): 1292. http://dx.doi.org/10.3390/cryst11111292.

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The electronic and optical properties of polythiophene (PT) for polymer light-emitting diodes (PLEDs) were calculated using density functional theory (DFT) and time-dependent DFT. We calculated the electronic and optical properties of thiophene and PT polymers with degrees of polymerization (DP) from 2 to 30 monomers (T1–T30) and their derivatives. The associated highest occupied molecular orbital (HOMO) energy, lowest unoccupied molecular orbital (LUMO) energy, band gaps, electron orbitals, and molecular structures were determined. As the DP increased, the LUMO energy gradually decreased, and the HOMO energy gradually increased. The band gap of PT approached 2 eV as the DP of the PT polymer increased from 1 to 30. The calculations and exchange–correlation functional were verified against values in the literature and experimental data from cyclic voltammetry (redox potential) and ultraviolet-visible, photoluminescence, and ultraviolet photoelectron spectra. The color of PT PLEDs can be adjusted by controlling the DP of the polymer and the substituents.
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5

Bilby, David, Bong Gi Kim, and Jinsang Kim. "Recent design strategies for polymer solar cell materials." Pure and Applied Chemistry 83, no. 1 (November 10, 2010): 127–39. http://dx.doi.org/10.1351/pac-con-10-08-23.

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Recent design tools for tuning the properties of conjugated polymers for efficient polymer solar cells (PSCs) are briefly reviewed. Based on limitations in the solar-to-electric energy conversion process imposed by material properties, recent research has focused on lowering the highest occupied molecular orbital (HOMO) level, reducing the bandgap, and controlling the molecular conformation and donor–acceptor phase separation. Additionally, the stability of PSCs can be improved through molecular design. Finally, a few less-conventional material design strategies for device improvement through polymer–polymer blends and triplet utilization are introduced. Molecular design has been an invaluable tool in controlling these material properties.
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6

Kato, Noriyuki, Shinya Ikeda, Manabu Hirakawa, and Hiroshi Ito. "Correlation of the Abbe Number, the Refractive Index, and Glass Transition Temperature to the Degree of Polymerization of Norbornane in Polycarbonate Polymers." Polymers 12, no. 11 (October 26, 2020): 2484. http://dx.doi.org/10.3390/polym12112484.

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The influences of the average degree of polymerization (Dp), which is derived from Mn and terminal end group, on optical and thermal properties of various refractive indexed transparent polymers were investigated. In this study, we selected the alicyclic compound, Dinorbornane dimethanol (DNDM) homo polymer, because it has been used as a representative monomer in low refractive index polymers for its unique properties. DNDM monomer has a stable amorphous phase and reacts like a polymer. Its unique reaction allows continuous investigation from monomer to polymer. For hydroxy end group and phenolic end group polymers, the refractive index (nd) decreased with increasing Dp, and both converged to same value in the high Dp region. However, the Abbe number (νd) of a hydroxy end group polymer is not dependent on Dp, and the νd of a phenolic end group polymer is greatly dependent on Dp. As for glass transition temperatures (Tg), both end group series were increased as Dp increased, and both converged to the same value.
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7

Akhmetkhanov, Rinat M., Valentina V. Chernova, Angela S. Shurshina, Mariya Yu Lazdina, and Elena I. Kulish. "Study of the formation of structures in solutions of chitosan – polyvinyl alcohol polymer blends." Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 23, no. 2 (June 4, 2021): 188–95. http://dx.doi.org/10.17308/kcmf.2021.23/3428.

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The aim of this work was the investigation of the formation of structures in solutions of individual polymers, as well as their blends with each other in buffer solvents with different values of pH. In this study we used a sample of chitosan (degree of deacetylation ~ 84 %, M = 130,000), which is a polycation when dissolved, and polyvinyl alcohol (r = 1.25 g/cm3, M = 5000). Buffer systems based on acetic acid and sodium acetate with pH = 3.8, 4.25, and 4.75 were used as solvents. Viscosimetry was used to determine the intrinsic viscosity, the degree of structuring, and the Huggins constant. The Kriegbaum method was used to determine the nature of the aggregates formed by the blend of the studied polymers. In the course of the research, it was shown that an increase in the pH of the acetate buffer used as a solvent was accompanied by a compression of the macromolecular coil (a decrease in intrinsic viscosity values), a deterioration in the quality of thesolvent (an increase in Huggins constant values), and an increase in the degree of polymer aggregation in a solution for chitosan polyelectrolyte. At the same time for a solution of polyvinyl alcohol the pH of the buffer practically did not affect the nature of the polymer-solvent interaction. It has been proved that polymer blends are characterized by an increase in aggregation processes and a decrease in the thermodynamic quality of the solvent in comparison with solutions of individual polymers. The size of the “combined” macromolecular coil, characterized by the intrinsic viscosity value for the polymer blend, which can be both above (buffer solvent with pH = 3.80) and below (buffer solvent with pH = 4.25 and 4.75) additivevalues, changed depending on the type of formed polymer-polymer aggregates (homo- or hetero-). It was established that the type of aggregates (homo- or hetero-) formed in solutions of polymer blends was determined not only by the thermodynamic quality of the used solvents, but also by the concentration of the polymers in the initial solutions
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8

Zhang, Zijian, Zicheng Ding, Chuandong Dou, Jun Liu, and Lixiang Wang. "Development of a donor polymer using a B ← N unit for suitable LUMO/HOMO energy levels and improved photovoltaic performance." Polymer Chemistry 6, no. 46 (2015): 8029–35. http://dx.doi.org/10.1039/c5py01389e.

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We report a novel approach to tune the LUMO/HOMO energy levels of polymer donors by replacing a C–C unit with a B ← N unit. The polymer containing a B ← N unit exhibits lower LUMO/HOMO levels and a narrower bandgap, leading to an improved photovoltaic performance.
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9

He, Baitian, Yulin Chen, Jinglong Chen, Songxi Chen, Manjun Xiao, Guiting Chen, and Chuanbo Dai. "Wide-bandgap donor polymers based on a dicyanodivinyl indacenodithiophene unit for non-fullerene polymer solar cells." RSC Advances 11, no. 35 (2021): 21397–404. http://dx.doi.org/10.1039/d1ra03233j.

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10

Ahmed, Sahnawaz, Nilotpal Singha, Bapan Pramanik, Julfikar Hassan Mondal, and Debapratim Das. "Redox controlled reversible transformation of a supramolecular alternating copolymer to a radical cation containing homo-polymer." Polymer Chemistry 7, no. 26 (2016): 4393–401. http://dx.doi.org/10.1039/c6py00809g.

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11

David, Tanya M. S., Cheng Zhang, and Sam-Shajing Sun. "Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative." Journal of Chemistry 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/379372.

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Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a specific example new polymer, a low energy gap, fully regioregular, terminal functionalized, and processable conjugated polymer poly-(3-dodecyloxy-2,5-thienylene vinylene) or PDDTV. The polymer exhibited an optical energy gap of 1.46 eV based on the UV-vis-NIR absorption spectrum. The electrochemically measured highest occupied molecular orbital (HOMO) level is −4.79 eV, resulting in the lowest unoccupied molecular orbital (LUMO) level of −3.33 eV based on optical energy gap. The polymer was synthesized via Horner-Emmons condensation and is fairly soluble in common organic solvents such as tetrahydrofuran and chloroform with gentle heating. DSC showed two endothermic peaks at 67°C and 227°C that can be attributed to transitions between crystalline and liquid states. The polymer is thermally stable up to about 300°C. This polymer appears very promising for cost-effective solar cell applications.
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12

Al-Janabi, Omer Yasin, Peter J. S. Foot, Emaad Taha Al-Tikrity, and Peter Spearman. "Synthesis and Characterisation of Novel Thiophene Based Azomethine Polymers and Study of Their Liquid Crystalline, Electrochemical and Optoelectronic Properties." Polymers and Polymer Composites 25, no. 5 (June 2017): 345–62. http://dx.doi.org/10.1177/096739111702500504.

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This work reports the synthesis, structural characterisation, liquid crystallinity, luminescence and electroluminescence of novel thiophene azomethine polymers. The polymers under study were prepared via oxidative polymerisation of four novel monomers at room temperature using iron (III) chloride. The chemical structures of the prepared monomers and polymers were confirmed by infrared and 1H and 13CNMR spectroscopy. Molecular masses were determined for monomers and polymers by gas/liquid chromatography-mass spectrometry (GC/LC-MS) and by gel-permeation (size exclusion) chromatography (SEC), respectively. Thermal stability studies of the prepared materials were achieved by thermogravimetric analysis (TGA), and the onset of weight loss To and the endset Tmax were calculated from the thermograms. Liquid crystalline mesophases and phase changes of the monomers and polymers were studied by differential scanning calorimetry (DSC) and polarised optical microscopy (POM), and the glass transition temperatures Tg of the polymers were determined from the DSC curves. The electrochemical band gaps, HOMO and LUMO energy levels were measured by cyclic voltammetry. UV-visible absorption-emission spectra (liquid and solid films) of the polymers were obtained at room temperature with different solvents. Optical band gaps were calculated from the absorption edges, and were in good agreement with those estimated from cyclic voltammetry. Mixing the polymers with lanthanide salts such as EuCl3 and YbCl3 gave modified fluorescence, and the light emitted was much more intense than that from the pure polymers. Polymer based light-emitting diodes (PLEDs) were fabricated by spin coating, and their current-voltage characteristics were measured. In preliminary work, the polymer devices were found to produce electroluminescent spectra similar to the PL spectra of the corresponding samples. Molecular modelling studies were performed both on polymer segments and monomer molecules; the absorption spectra of the prepared polymers, HOMO and LUMO energy levels were calculated with ZINDO using AMI geometry optimisation.
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13

Zhang, Bin, Guiting Chen, Jin Xu, Liwen Hu, and Wei Yang. "Feasible energy level tuning in polymer solar cells based on broad band-gap polytriphenylamine derivatives." New Journal of Chemistry 40, no. 1 (2016): 402–12. http://dx.doi.org/10.1039/c5nj02124c.

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Four triphenylamine based broad band-gap polymers with different substituted groups [–OC8H17, –C8H17, –CF3, –(CF3)2] were designed and synthesized, and the HOMO energy levels and Vocs of these polymer based PSCs could be tuned feasibly.
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14

Wang, Qing Qi, and Qing Xu. "Synthesis and Properties of Novel Polymer Electronic-Phosphorescent Materials." Advanced Materials Research 668 (March 2013): 250–54. http://dx.doi.org/10.4028/www.scientific.net/amr.668.250.

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In this paper, the method of Poly(N-vinylcarbazole)-co-di(2-(4-methylphenyl) (MSPD) Iridium(III))(NVK-MMI) preparation was carried out. The novel polymer were based on phosphorescent polymers involving a carbazole unit and an iridium-complex unit. The structure of the polymer were characterized by elemental analyses, FTIR, and 1H NMR. The UV-Vis absorption and photoluminescence (PL) spectra of the complexes were investigated. These results indicated they should be applied in the field of OLED. The NVK-MMI optical bandgap is calculated to be 2.25 eV. Cyclic voltammetry results confirm that the LUMO and HOMO levels of NVK- MMI were calculated as -3.02 and -5.27 eV, respectively.
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15

Mao, Tengfei, Yanzi Gou, Jun Wang, and Hao Wang. "Synthesis and properties of well-defined carbazole-containing fluorescent star polymers of different arms." e-Polymers 17, no. 1 (January 1, 2017): 15–22. http://dx.doi.org/10.1515/epoly-2016-0076.

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AbstractA series of fluorescent carbazole-containing star polymers with different arms were successfully synthesized using 9-(4-vinylbenzyl)9H-carbazole (VBCz) as monomer and multifunctional bromide as initiators via atom transfer radical polymerization (ATRP). The effect of the poly(9-(4-vinylbenzyl)-9H-carbazole) (PVBCz) star polymer architecture on their optical and electrochemical properties was investigated. All of the PVBCz star polymers absorbed light in the range of 280–360 nm both in solution and as polymer films. Meanwhile, the star polymers exhibited maximum fluorescent emission at 350 nm in solution, while at 406 nm as films. Moreover, the star polymers with different arm numbers showed different photoluminescence quantum efficiency and highest and lowest occupied molecular orbital (HOMO, LOMO, respectively) energy levels. It is proved that the PVBCz star polymers exhibited different photoelectronic properties by varying the molecular architectures.
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16

González García, Álvaro, Alessandro Ianiro, Roos Beljon, Frans A. M. Leermakers, and Remco Tuinier. "(Homo)polymer-mediated colloidal stability of micellar solutions." Soft Matter 16, no. 6 (2020): 1560–71. http://dx.doi.org/10.1039/c9sm01665a.

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17

Shetti, Vijayendra S. "Chemical syntheses and salient features of azulene-containing homo- and copolymers." Beilstein Journal of Organic Chemistry 17 (August 24, 2021): 2164–85. http://dx.doi.org/10.3762/bjoc.17.139.

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Azulene is a non-alternant, aromatic hydrocarbon with many exciting characteristics such as having a dipole moment, bright color, stimuli responsiveness, anti-Kasha photophysics, and a small HOMO–LUMO gap when compared to its isomer, naphthalene. These properties make azulene-containing polymers an intriguing entity in the field of functional polymers, especially for organic electronic applications like organic field-effect transistors (OFET) and photovoltaic (PV) cells. Since azulene has a fused five and seven-membered ring structure, it can be incorporated onto the polymer backbone through either of these rings or by involving both the rings. These azulene-connection patterns can influence the properties of the resulting polymers and the chemical synthesis in comparison to the electrochemical synthesis can be advantageous in obtaining desired patterns of substitution. Hence, this review article presents a comprehensive overview of the developments that have taken place in the last three decades in the field of chemical syntheses of azulene-containing homo- and copolymers, including brief descriptions of their key properties.
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18

Wei, Yong Sen. "Narrow-Band-Gap Polymer Photovoltaic Materials Synthesis and Photovoltaic Research." Applied Mechanics and Materials 273 (January 2013): 468–72. http://dx.doi.org/10.4028/www.scientific.net/amm.273.468.

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In recent years, research of the narrow-band-gap polymer photovoltaic (PV) materials in the field of light-emitting diodes, field effect transistors, solar cells and sensors has made tremendous progress and its application becomes more widely. In order to obtain a better performance of the photovoltaic material, in the process of design the polymer, we must consider the spectral range, the energy gap, the balance between the LUMO and HOMO level. Through the analysis of the narrow-band-gap polymers, this paper described the synthesis of the photovoltaic material, and detailed analyzes its photovoltaic characteristics. This paper introduces the double bonds to combine DTBT receptors and different electron donor, to synthesize new narrow-band-gap polymer photovoltaic materials with photovoltaic properties.
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19

Misin, Vyacheslav M., Irina E. Maltseva, Alexander A. Maltsev, Alexander V. Naumkin, and Mark E. Kazakov. "Anionic Polymerization of Para-Diethynylbenzene: Synthesis of a Strictly Linear Polymer." Polymers 14, no. 5 (February 24, 2022): 900. http://dx.doi.org/10.3390/polym14050900.

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Anionic homo- and copolymerization of p-diethynylbenzene in the presence of n-BuLi in polar solvents was carried out. The use of hexamethylphosphortriamide (HMPA) makes it possible to synthesize a completely linear soluble polymer that does not have branching and phenylene fragments. A copolymer of p-diethynylbenzene with diphenyldiacetylene was synthesized. Homo- and copolymers of p-diethynylbenzene have high thermo- and thermo-oxidative stability. By the interaction of side reactive ethynylphenylene groups with various reagents, it is proposed to synthesize clusters along the conducting chain of poly-p-diethynylbenzene. Due to presenting C≡CH side groups, boron, copper, and cobalt derivatives were synthesized. It is shown that not all theoretically possible stereoisomers can be formed as a result of the polymerization. The application of p-diethynylbenzene polymers for the modification of industrial samples of epoxy novolac resin, oligoester acrylates, and carbon fibers has been demonstrated.
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20

Zhang, Qiang, Po-I. Wang, Guang Liang Ong, Shen Hoong Tan, Zhong Wei Tan, Yew Han Hii, Yee Lin Wong, et al. "Photophysical and Electroluminescence Characteristics of Polyfluorene Derivatives with Triphenylamine." Polymers 11, no. 5 (May 9, 2019): 840. http://dx.doi.org/10.3390/polym11050840.

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In this work, polymers of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-triphenylamine] with side chains containing: pyrene (C1), diphenyl (C2), naphthalene (C3), and isopropyl (C6) structures were synthesized via a Suzuki coupling reaction. The structures were verified using NMR and cyclic voltammetry measurements provide the HOMO and LUMO of the polymers. The polymer with pyrene (C1) and naphthalene (C3) produced photoluminescence in the green while the polymer with the side chain containing diphenyl (C2) and isopropyl (C6) produce dual emission peaks of blue-green photoluminescence (PL). In order to examine the electroluminescence properties of the polymers, the solutions were spin-coated onto patterned ITO anode, dried, and subsequently coated with an Al cathode layer to form pristine single layer polymer LEDs. The results are compared to a standard PFO sample. The electroluminescence spectra resemble the PL spectra for C1 and C3. The devices of C2, C3, and C6 exhibit voltage-dependent EL. An additional red emission peak was detected for C2 and C6, resulting in spectra with peaks at 435 nm, 490 nm, and 625 nm. The effects of the side chains on the spectral characteristics of the polymer are discussed.
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21

Saito, Masahiko, and Itaru Osaka. "A Thiazolothiazole-Based Semiconducting Polymer with Well-Balanced Hole and Electron Mobilities." Applied Sciences 9, no. 3 (January 29, 2019): 451. http://dx.doi.org/10.3390/app9030451.

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We report the synthesis and properties of a new thiazolothiazole (TzTz)-based semiconducting polymer incorporating the dithienothienothiophenebisimide (TBI) unit, named PTzTBI. PTzTBI showed relatively deep HOMO and LUMO energy levels of −5.48 and −3.20 eV, respectively. Although PTzTBI mainly formed face-on backbone orientation unfavorable for transistors, PTzTBI functioned as an ambipolar semiconductor for the first time with TzTz-based polymers, with reasonably high and well-balanced hole (0.02 cm2 V−1 s−1) and electron (0.01 cm2 V−1 s−1) mobilities.
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22

Shao, Yun, Liusheng Chen, Qi Liao, Heng Jiang, Zhitian Liu, Xigao Jin, and Limin Gao. "Characterization of Response Frequency for the Pressure-Sensitive Paint Based on Fluorine-Containing Polymer Matrixes Using Oscillating Sound Wave Technique." Sensors 20, no. 21 (November 5, 2020): 6310. http://dx.doi.org/10.3390/s20216310.

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Five kinds of new homo-polymer and copolymers of methacrylate containing a fluorine ester group were synthesized and used for the binder of pressure-sensitive paint (PSP)to ensure the good compatibility between luminophore (Pt(II) meso-tetra (pentafluorophenyl) porphine (PtTFPP)) and polymer binder. In the work, we were concerned with how the structure of thesepolymers containing fluorine, especially the various ester group structure, affects the response frequency of PSP using oscillating sound wave technique. The results showed that the pressure sensitivities (Sp) of these PSP samples containing different polymers, exhibit some difference. The length of ester chain on the methacrylatepolymer affects the response frequency of PSP sensor layer composed of the polymer. The longer the chain length of the ester group, the higher the response frequency of the PSP sensor layer quenching by oxygen.
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23

Jintakanon, N., Pakorn Opaprakasit, Atitsa Petchsuk, and Mantana Opaprakasit. "Controlled-Release Materials for Fertilizer Based on Lactic Acid Polymers." Advanced Materials Research 55-57 (August 2008): 905–8. http://dx.doi.org/10.4028/www.scientific.net/amr.55-57.905.

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ontrolled-release materials for urea are prepared by spray coating urea granulates with lactic acid based homo- and co-polymers solutions. Percent coating as a function of polymer types, molecular weight, polymer concentration, and dose applications are examined by gravimetric analysis. Percentage of urea dissolution in water of the coated fertilizer is measured by monitoring refractive index of the solutions. Morphology of the polymer coating surfaces is revealed by Scanning Electron Microscopy (SEM). It was found that an amount of cracks and pin-holes, which is dependent on polymer types and molecular weight, plays a significant role in controlling the rate of urea release. Results from urea dissolution test also suggests that the synthesized poly(lactic acid-co-ethylene terephthalate) show urea-holding efficiency comparable to that of commercial PLA, despite its much lower molecular weight, indicating that the copolymer is potentially suitable for this specific application.
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24

Zhu, Dangqiang, Liang Sun, Xichang Bao, Shuguang Wen, Liangliang Han, Chuantao Gu, Jing Guo, and Renqiang Yang. "Low band-gap polymers based on easily synthesized thioester-substituted thieno[3,4-b]thiophene for polymer solar cells." RSC Advances 5, no. 77 (2015): 62336–42. http://dx.doi.org/10.1039/c5ra13381e.

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25

R. Murad, Ary, Ahmed Iraqi, Shujahadeen B. Aziz, Sozan N. Abdullah, and Mohamad A. Brza. "Conducting Polymers for Optoelectronic Devices and Organic Solar Cells: A Review." Polymers 12, no. 11 (November 9, 2020): 2627. http://dx.doi.org/10.3390/polym12112627.

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In this review paper, we present a comprehensive summary of the different organic solar cell (OSC) families. Pure and doped conjugated polymers are described. The band structure, electronic properties, and charge separation process in conjugated polymers are briefly described. Various techniques for the preparation of conjugated polymers are presented in detail. The applications of conductive polymers for organic light emitting diodes (OLEDs), organic field effect transistors (OFETs), and organic photovoltaics (OPVs) are explained thoroughly. The architecture of organic polymer solar cells including single layer, bilayer planar heterojunction, and bulk heterojunction (BHJ) are described. Moreover, designing conjugated polymers for photovoltaic applications and optimizations of highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy levels are discussed. Principles of bulk heterojunction polymer solar cells are addressed. Finally, strategies for band gap tuning and characteristics of solar cell are presented. In this article, several processing parameters such as the choice of solvent(s) for spin casting film, thermal and solvent annealing, solvent additive, and blend composition that affect the nano-morphology of the photoactive layer are reviewed.
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26

Loch, Jennifer A., and Robert H. Crabtree. "Rapid screening and combinatorial methods in homogeneous organometallic catalysis." Pure and Applied Chemistry 73, no. 1 (January 1, 2001): 119–28. http://dx.doi.org/10.1351/pac200173010119.

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Methods are discussed for rapid screening of soluble and polymer-bound homo-geneous catalysts for activity. A polymer-bound phosphine library is synthesized, and a modular tridentate pincer CNC bis-carbene Pd complex is described. The possibility of C-bound His in metalloenzymes is raised.
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27

Javan Nikkhah, Sousa, Elsi Turunen, Anneli Lepo, Tapio Ala-Nissila, and Maria Sammalkorpi. "Multicore Assemblies from Three-Component Linear Homo-Copolymer Systems: A Coarse-Grained Modeling Study." Polymers 13, no. 13 (June 30, 2021): 2193. http://dx.doi.org/10.3390/polym13132193.

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Multicore polymer micelles and aggregates are assemblies that contain several cores. The dual-length-scale compartmentalized solvophobic–solvophilic molecular environment makes them useful for, e.g., advanced drug delivery, high-precision synthesis platforms, confined catalysis, and sensor device applications. However, designing and regulating polymer systems that self-assemble to such morphologies remains a challenge. Using dissipative particle dynamics (DPD) simulations, we demonstrate how simple, three-component linear polymer systems consisting of free solvophilic and solvophobic homopolymers, and di-block copolymers, can self-assemble in solution to form well-defined multicore assemblies. We examine the polymer property range over which multicore assemblies can be expected and how the assemblies can be tuned both in terms of their morphology and structure. For a fixed degree of polymerization, a certain level of hydrophobicity is required for the solvophobic component to lead to formation of multicore assemblies. Additionally, the transition from single-core to multicore requires a relatively high solvophobicity difference between the solvophilic and solvophobic polymer components. Furthermore, if the solvophilic polymer is replaced by a solvophobic species, well-defined multicore–multicompartment aggregates can be obtained. The findings provide guidelines for multicore assemblies’ formation from simple three-component systems and how to control polymer particle morphology and structure.
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Song, Jian Hua, and San Jun Fan. "Preparation and Analysis of Homo-Polymer and Copolymer from Tetra-Coordinate Silicate." Advanced Materials Research 550-553 (July 2012): 752–56. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.752.

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Highly reactive penta-coordinate organic silicon was prepared by the reaction of silica with ethylene glycol and potassium hydroxide, which reacted with 4-vinylbenzyl chloride to synthesize a new 4-vinyl benzyl tetra-coordinate silicate (VBTCS), and the new monomer was homo-polymerized and copolymerized with styrene and methyl acrylate via free radical polymerization, respectively. Tetra-coordinate silicon monomer, homo-polymer, and copolymers were characterized by IR, EA, TG, DSC, GPC etc.
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29

Esiner, Serkan, Gijs W. P. van Pruissen, Martijn M. Wienk, and René A. J. Janssen. "Optimized light-driven electrochemical water splitting with tandem polymer solar cells." Journal of Materials Chemistry A 4, no. 14 (2016): 5107–14. http://dx.doi.org/10.1039/c5ta10459a.

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30

Xu, Xiushang, Xuefei Li, Shumeng Wang, Junqiao Ding, and Lixiang Wang. "Deep-blue emitting poly[spiro(dibenzoazasiline-10′,9-silafluorene)] for power-efficient PLEDs." Journal of Materials Chemistry C 6, no. 36 (2018): 9599–606. http://dx.doi.org/10.1039/c8tc03074j.

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31

Bicciocchi, Erika, Matthias Haeussler, Ezio Rizzardo, Andrew D. Scully, and Kenneth P. Ghiggino. "An Alternating Donor–Acceptor Conjugated Polymer Based on Benzodithiophene and [3,4-c]pyrrole-4,6-dione: Synthesis, Characterization, and Application in Photovoltaic Devices." Australian Journal of Chemistry 68, no. 11 (2015): 1773. http://dx.doi.org/10.1071/ch15457.

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The synthesis is described of a new alternating donor–acceptor semiconducting polymer based on an N-octylthieno[3,4-c]pyrrole-4,6-dione building block together with a newly designed 2,3-bis(2-ethylhexyl)thiophenylethynyl substituted benzodithiophene (BDT). The introduction of electron-rich thiophene units to BDT raises the highest occupied molecular orbital (HOMO) level of the conjugated polymer and the concomitant reduction of the bandgap enhances the harvesting of solar radiation. This modification also introduces less sterically demanding triple bonds, thereby potentially enabling more favourable molecular interactions and an extra dimension of conjugation perpendicular to the main polymer chain. The optoelectronic properties of this new conjugated polymer were evaluated using UV-visible absorption and fluorescence spectroscopy, photoelectron spectroscopy in air, photo-induced charge extraction by linearly increasing voltage (Photo-CELIV), and density functional theory calculations. The polymer absorbs broadly in the wavelength range 300–700 nm in solution and the solid state. The estimated HOMO and LUMO levels of −5.4 and −3.6 eV, respectively, correspond to a bandgap of 1.8 eV. Photovoltaic devices fabricated using the polymer as the active layer displayed power conversion efficiencies (PCEs) of up to 1 %. Photo-CELIV results provide evidence that rapid recombination and poor charge mobility are likely contributing factors to the relatively low PCE values observed.
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32

Zhang, Tao, Yunhao Du, Jana Kalbacova, René Schubel, Raul D. Rodriguez, Tao Chen, Dietrich R. T. Zahn, and Rainer Jordan. "Wafer-scale synthesis of defined polymer brushes under ambient conditions." Polymer Chemistry 6, no. 47 (2015): 8176–83. http://dx.doi.org/10.1039/c5py01274k.

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33

Wan, Meixiu, Hongbing Zhu, Juan Liu, and Lijun Huo. "Poly(benzo[2,1-b:3,4-b′]dithiophene-alt-isoindigo): a low bandgap polymer showing a high open circuit voltage in polymer solar cells." RSC Advances 5, no. 1 (2015): 269–73. http://dx.doi.org/10.1039/c4ra12171f.

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A novel polymer of PBDP-IID was synthesized and its HOMO descends to −5.44 eV. Bulk heterojunction solar cells made from PBDP-IID exhibited a high Voc of 0.95 V, which shows the highest value among the PSCs based on the narrow bandgap polymer donors with Eg < 1.6 eV.
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34

Bürgermeister, Lisa, Marcus Hermann, Katalin Fehér, Catalina Molano Lopez, Andrij Pich, Julian Hannen, Felix Vogt, and Wolfgang Schulz. "Modelling pH-Optimized Degradation of Microgel-Functionalized Polyesters." Journal of Healthcare Engineering 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/8125416.

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We establish a novel mathematical model to describe and analyze pH levels in the vicinity of poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-N-vinylimidazole) (VCL/AAEM/VIm) microgel-functionalized polymers during biodegradation. Biodegradable polymers, especially aliphatic polyesters (polylactide/polyglycolide/polycaprolactone homo- and copolymers), have a large range of medical applications including delivery systems, scaffolds, or stents for the treatment of cardiovascular diseases. Most of those applications are limited by the inherent drop of pH level during the degradation process. The combination of polymers with VCL/AAEM/VIm-microgels, which aims at stabilizing pH levels, is innovative and requires new mathematical models for the prediction of pH level evaluation. The mathematical model consists of a diffusion-reaction PDE system for the degradation including reaction rate equations and diffusion of acidic degradation products into the vicinity. A system of algebraic equations is coupled to the degradation model in order to describe the buffering action of the microgel. The model is validated against the experimental pH-monitored biodegradation of microgel-functionalized polymer foils and is available for the design of microgel-functionalized polymer components.
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35

Goulart, G., J. Y. Sanchez, and M. Armand. "Synthesis and electrochemical characterization of new polymer electrolytes based on dioxolane homo and co-polymers." Electrochimica Acta 37, no. 9 (January 1992): 1589–92. http://dx.doi.org/10.1016/0013-4686(92)80117-5.

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36

Zhou, Huiqiong, Yuan Zhang, Cheng-Kang Mai, Samuel D. Collins, Guillermo C. Bazan, Thuc-Quyen Nguyen, and Alan J. Heeger. "Polymer Homo-Tandem Solar Cells with Best Efficiency of 11.3%." Advanced Materials 27, no. 10 (January 21, 2015): 1767–73. http://dx.doi.org/10.1002/adma.201404220.

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37

Nan, Yang, Jiajia Shao, Morten Willatzen, and Zhong Lin Wang. "Understanding Contact Electrification at Water/Polymer Interface." Research 2022 (February 16, 2022): 1–10. http://dx.doi.org/10.34133/2022/9861463.

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Contact electrification (CE) involves a complex interplay of physical interactions in realistic material systems. For this reason, scientific consensus on the qualitative and quantitative importance of different physical mechanisms on CE remains a formidable task. The CE mechanism at a water/polymer interface is a crucial challenge owing to the poor understanding of charge transfer at the atomic level. First-principle density functional theory (DFT), used in the present work, proposes a new paradigm to address CE. Our results indicate that CE follows the same trend as the gap between the highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) of polymers. Electron transfer occurs at the outmost atomic layer of the water/polymer interface and is closely linked to the functional groups and atom locations. When the polymer chains are parallel to the water layer, most electrons are transferred; conversely, if they are perpendicular to each other, the transfer of charges can be ignored. We demonstrate that a decrease in the interface distance between water and the polymer chains leads to CE in quantitative agreement with the electron cloud overlap model. We finally use DFT calculations to predict the properties of CE materials and their potential for triboelectric nanogenerator energy harvesting devices.
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38

Thuéry, Pierre, and Jack Harrowfield. "Uranyl ion complexes with 2,2′:6′,2′′-terpyridine-4′-carboxylate. Interpenetration of networks involving “expanded ligands”." CrystEngComm 23, no. 41 (2021): 7305–13. http://dx.doi.org/10.1039/d1ce01215k.

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39

Goel, Mahima, Marie Siegert, Gert Krauss, John Mohanraj, Adrian Hochgesang, David C. Heinrich, Martina Fried, Jens Pflaum, and Mukundan Thelakkat. "HOMO–HOMO Electron Transfer: An Elegant Strategy for p‐Type Doping of Polymer Semiconductors toward Thermoelectric Applications." Advanced Materials 32, no. 43 (September 18, 2020): 2003596. http://dx.doi.org/10.1002/adma.202003596.

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40

Honsho, Yoshihito, Akinori Saeki, and Shu Seki. "Effects of Molecular Structure on Intramolecular Charge Carrier Transport in Dithieno [3,2-b: -d] Pyrrole-Based Conjugated Copolymers." International Journal of Spectroscopy 2012 (April 8, 2012): 1–7. http://dx.doi.org/10.1155/2012/983523.

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Intramolecular mobility of positive charge carriers in conjugated polymer films based on dithieno [2,3-b: -d] pyrrole (DTP) is studied by time-resolved microwave conductivity (TRMC). A series of DTP homopolymer and copolymers combined with phenyl, 2,-biphenyl, thiophene, 2,-bithiophene, and 9,-dioctylfluorene were synthesized by Suzuki-Miyaura and Yamamoto coupling reactions. Polymers containing DTP unit are reported to show high value of hole mobility measured by FET method, and this type of polymers is expected to have stable HOMO orbitals which are important for hole transportation. Among these copolymers, DTP coupled with 9,-dioctylfluorene copolymer showed the highest charge carrier mobility as high as 1.7 cm2/Vs, demonstrating an excellent electrical property on rigid copolymer backbones.
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41

Chroni, Angeliki, and Stergios Pispas. "Nano-Sized Polyelectrolyte Complexes Formed between Poly(vinyl benzyl trimethyl ammonium chloride) and Insulin." Micro 2, no. 2 (May 17, 2022): 313–24. http://dx.doi.org/10.3390/micro2020020.

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Novel biohybrid homo-polyelectrolyte-based nanocarriers were formed by the complexation of insulin (INS) with a biocompatible and cationic polyelectrolyte, namely, poly(vinyl benzyl trimethylammonium chloride) (PVBTMAC). According to light-scattering techniques, the hydrophilic PVBTMAC homo-polyelectrolyte forms single chains in aqueous media. The resulting biohybrid PVBTMAC/INS nanocarriers were formed via electrostatic co-assembly. The effects of polyelectrolyte structure and content on the characteristics of the formed PVBTMAC/INS complexes were studied. A significant aggregation tendency of the PVBTMAC/INS complexes was observed, based on the physicochemical results, especially at high protein concentration, corroborating the effective electrostatic interaction of INS with the cationic polyelectrolyte. The physicochemical properties of the formed PVBTMAC/INS nanocarriers depended on the concentration of the stock polymer and INS solutions. A neat PVBTMAC homo-polymer and PVBTMAC/INS nanocarriers demonstrated good serum stability in the presence of fetal bovine serum (FBS) proteins. Fluorescence spectroscopy (FS) studies revealed no INS conformational changes after its complexation with the cationic PVBTMAC polyelectrolyte. The obtained PVBTMAC/INS complexes demonstrated considerable and promising characteristics for potential use as insulin delivery systems.
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42

Li, Wei-Long, Cheng-Hung Hou, Chi-Ming Yang, Kuen-Wei Tsai, Jhao-Lin Wu, Yu-Tang Hsiao, Chintam Hanmandlu, et al. "Perfluorinated ionomer and poly(3,4-ethylenedioxythiophene) colloid as a hole transporting layer for optoelectronic devices." Journal of Materials Chemistry A 9, no. 33 (2021): 17967–77. http://dx.doi.org/10.1039/d1ta04362e.

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A polymer-based hole-transporting layer (HTL) with a tunable work function and highest occupied molecular orbital (HOMO) position was demonstrated to effectively optimize the anode junctions of optoelectronic devices.
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43

Wang, Wei, Minqiao Ren, Liping Hou, Shuzhang Qu, Xinwei Li, and Zifang Guo. "Polymerization of Allyltrimethylisilane and 4-Methyl-1-Pentene by Using Metallocene Catalysts." Polymers 15, no. 9 (April 25, 2023): 2038. http://dx.doi.org/10.3390/polym15092038.

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Polymers of higher olefin, obtained by Ziegler-type polymerization, have been used in some critical fields, e.g., as the membrane for extracorporeal membrane oxygenation (ECMO), which plays an important role in the treatment of patients with severe COVID-19. The polymer obtained by a single-site catalyst, e.g., metallocene catalysts, demonstrated a higher performance. The homo- and co-polymerization of allyltrimethylisilane (ATMS) and 4-methyl-1-pentene (4M1P) were conducted using syndiospecific (cat 1) and isospecific (cat 2) metallocene catalysts. Cat 1 showed low conversions and provided a polymer with a higher molecular weight, while cat 2 behaved oppositely. 13C-NMR spectra certified the stereotacticity of the resultant polymer, and the resonance of the carbon atom of CH2 (αα’) between the two tertiary carbon atoms of the ATMS and 4M1P units were observed. This could be the evidence of the formation of a true copolymer. The crystallization of the polymer was explored using a differential scanning calorimeter (DSC) and wide angle X-ray diffraction (WAXD). All homopolymers and some of the copolymers showed high melting temperatures and low melting enthalpies. The WAXD patterns of the syndiotactic polymer and isotactic homopolymer or the ATMS-rich copolymer were consistent with the reported literature, but the isotactic 4M1P-rich copolymer provided the crystal form I, which is unusual for a 4M1P polymer without any pretreatment.
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44

Alobad, Z. K., M. Albozahid, H. Z. Naji, H. S. Alraheem, and A. Saiani. "Influence of hard segments content on thermal, morphological and mechanical properties of homo and co-polyurethanes: a comparative study." Archives of Materials Science and Engineering 1, no. 109 (May 1, 2021): 5–16. http://dx.doi.org/10.5604/01.3001.0015.0510.

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Purpose: This work aims to study the effect of hard segments (HS) content on the thermal, morphological and mechanical properties of polyurethane polymers based on 1.5 pentanediol chain extenders. Design/methodology/approach: Two comparable series of polyurethanes were synthesised including homo-polyurethane (Homo-PU) and copolyurethane (Co-PU). The Homo-PU consists of 100% wt. of hard segments (HS). The Co-PU composes of 30%wt. of soft segments (SS) using a poly(ethylene glycol)-block-poly(propylene glycol)-blockpoly( ethylene glycol) material. The effect of hard segments content on the morphology of Homo-PU and Co-PU was also studied. Findings: The Homo-PU and Co-PU materials show three distinct degradation steps with the higher thermal stability of the Co-PU compared to the Homo-PU. Enthalpy of fusion (ΔHM) and heat capacity (ΔCP) of polyurethane (PU) samples decrease with decreasing HS content. In the cooling cycle, the higher exothermic peak of crystallization is observed in the Co-PU. In contrast, the cold crystalline peak is observed in the 2nd heating cycle of the Homo-PU. Melting temperature (TM) increases with increasing SS content. Glass transition temperature (Tg) of PU samples shifts to higher temperature with increasing HS content. Storage modulus (E’) of the Co-PU is higher than E’ of the Homo-PU. All N-H groups in PU samples are hydrogen-bonded, whilst most of the C=O groups are hydrogen-bonded. The degree of hydrogen bonding in PU samples decreases with decreasing HS content. The Homo-PU shows better hardness than the Co-PU and higher brittleness at low temperature. WAXS results of the Homo-PU display better crystallinity compared to the Co-PU. Research limitations/implications: The main challenge in this work was how to synthesis Thermoplastic polyurethanes (TPUs) with specific properties to compete other common polymer such as Polyamides (PA) and Polypropylene (PP).Practical implications: Thermoplastic polyurethanes (TPUs) can be used in various application such as backageing, foot,automobiles and constructions. Originality/value: A new type of TPUs that synthesized using different type of chain extender (1.5 pentanediol). Two different types of TPUs were synthesized one contained 30% SS and 70% HS and a second one contained 100% HS.
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45

Dilonardo, Elena, Maria M. Giangregorio, Maria Losurdo, Pio Capezzuto, Giovanni Bruno, Antonio Cardone, Carmela Martinelli, Gianluca M. Farinola, Francesco Babudri, and Francesco Naso. "Tailoring Optical Properties of Blue-Gap Poly(p-phenylene Vinylene)s for LEDs Applications." Advances in Science and Technology 75 (October 2010): 118–23. http://dx.doi.org/10.4028/www.scientific.net/ast.75.118.

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There has been growing interest in developing new semiconducting polymers for applications in optoelectronics (OLEDs) due to their exceptional processability and appealing characteristic of manipulating electronic and optical properties by tuning of molecular structure and self-assembling. This study is an investigation on the interplay among supermolecular organization and optical properties of thin films of the poly[2-(2-ethylhexyloxy)-5-methoxy]-1, 4-phenylenedifluorovinylene (MEH-PPDFV) conjugated polymer, which has fluorinated vinylene units. This interplay is elucidated exploiting atomic force microscopy, spectroscopy ellipsometry, photoluminescence and electroluminescence. Thin films of MEH-PPDFV have been deposited by drop casting on indium-tin-oxide (ITO), quartz and glass substrates. The dependence of polymer chains self-organization and morphology on substrate surface is presented. Furthermore, it is demonstrated that the presence of F-atoms in the vinylene units of the MEH-PPDFV yields a blue optical band gap with the maximum of the fundamental HOMO-LUMO transition at 331 nm and photoluminescence at 458 nm. The OLED built with the above polymer shows a very stable blue-greenish electroluminescence that is also achieved at 504 nm.
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46

Mantela, Marilena, Konstantinos Lambropoulos, Marina Theodorakou, and Constantinos Simserides. "Quasi-Periodic and Fractal Polymers: Energy Structure and Carrier Transfer." Materials 12, no. 13 (July 6, 2019): 2177. http://dx.doi.org/10.3390/ma12132177.

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We study the energy structure and the coherent transfer of an extra electron or hole along aperiodic polymers made of N monomers, with fixed boundaries, using B-DNA as our prototype system. We use a Tight-Binding wire model, where a site is a monomer (e.g., in DNA, a base pair). We consider quasi-periodic (Fibonacci, Thue–Morse, Double-Period, Rudin–Shapiro) and fractal (Cantor Set, Asymmetric Cantor Set) polymers made of the same monomer (I polymers) or made of different monomers (D polymers). For all types of such polymers, we calculate the highest occupied molecular orbital (HOMO) eigenspectrum and the lowest unoccupied molecular orbital (LUMO) eigenspectrum, the HOMO–LUMO gap and the density of states. We examine the mean over time probability to find the carrier at each monomer, the frequency content of carrier transfer (Fourier spectra, weighted mean frequency of each monomer, total weighted mean frequency of the polymer), and the pure mean transfer rate k. Our results reveal that there is a correspondence between the degree of structural complexity and the transfer properties. I polymers are more favorable for charge transfer than D polymers. We compare k ( N ) of quasi-periodic and fractal sequences with that of periodic sequences (including homopolymers) as well as with randomly shuffled sequences. Finally, we discuss aspects of experimental results on charge transfer rates in DNA with respect to our coherent pure mean transfer rates.
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47

Wang, Dengfei, Shiyan Li, Ying Lu, Jian Wang, and Yongfeng Men. "Melt Memory Effect in Polyethylene Random Terpolymer with Small Amount of 1-Octene and 1-Hexene Co-Units: Non-Isothermal and Isothermal Investigations." Polymers 15, no. 7 (March 30, 2023): 1721. http://dx.doi.org/10.3390/polym15071721.

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Homo-polymers of reasonable molecular weight relax very fast in the molten state. Starting from a semi-crystalline structure, when the homo-polymer is heated up to a temperature higher than its nominal melting temperature, it relaxes quickly into a homogenous molten state. The following crystallization temperature during cooling remains constant irrespective of the melt temperature. However, the situation is evidently different in copolymers. A phenomenon named the crystallization melt memory effect denotes an increased crystallization rate during cooling after a polymer was melted at different temperatures, which is often observed. The melt temperature can be even higher than the equilibrium melting temperature of the corresponding polymer crystals. In this work, we investigated such memory effect in a polyethylene random terpolymer with a small fraction of 1-octene and 1-hexene co-units using differential scanning calorimetry techniques. Both non-isothermal and isothermal protocols were employed. In non-isothermal tests, a purposely prepared sample with well defined thermal history (the sample has been first conditioned at 200 °C for 5 min to eliminate the thermal history and then cooled down to −50 °C) was melted at different temperatures, followed by a continuous cooling at a constant rate of 20 °C/min. Peak crystallization temperature during cooling was taken to represent the crystallization rate. Whereas, in isothermal tests, the same prepared sample with well defined thermal history was cooled to a certain crystallization temperature after being melted at different temperatures. Here, time to complete the isothermal crystallization was recorded. It was found that the results of isothermal tests allowed us to divide the melt temperature into four zones where the features of the crystallization half time change.
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48

Shin, Jisoo, Min Kim, Boseok Kang, Jaewon Lee, Heung Gyu Kim, and Kilwon Cho. "Impact of side-chain fluorination on photovoltaic properties: fine tuning of the microstructure and energy levels of 2D-conjugated copolymers." Journal of Materials Chemistry A 5, no. 32 (2017): 16702–11. http://dx.doi.org/10.1039/c7ta04098a.

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The control of the molecular energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is crucial to the design of highly efficient polymer solar cells (PSCs).
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49

Xiao, Nan, Liu Qian, Jiamin Cao, Xiaojuan Zhao, Aihong Han, and Liming Ding. "A zigzag fused-ring building block for polymer solar cells." New Journal of Chemistry 40, no. 6 (2016): 4895–98. http://dx.doi.org/10.1039/c6nj00067c.

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50

Manjunatha, M. G., Airody Vasudeva Adhikari, and Pramod Kumar Hegde. "Optical and Electrochemical Properties of a New Donor-Acceptor Type Conjugated Polymer Derived from Thiophene, Carbazole and 1,3,4-Oxadiazole Units." Materials Science Forum 657 (July 2010): 46–55. http://dx.doi.org/10.4028/www.scientific.net/msf.657.46.

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A new donor-acceptor type poly[3-{5-[3,4-didecyloxy-5-(1,3,4-oxadiazol-2-yl)thiophen-2-yl]-1,3,4-oxadiazol-2-yl}-9-dodecyl-9H-carbazole] (P) has been synthesized starting from thiodiglycolic acid and 9H-carbazole through multistep reactions. The polymer has been synthesized through precursor polyhydrazide route. The weight average molecular weight of the polymer was found to be 7210. The polymer exhibited intense green fluorescence in solid sate. Cyclic voltammetric experiments showed that the polymer has low-lying LUMO (-3.55 eV) and high lying HOMO (-5.77 eV) energy levels due to the presence of alternate donor and acceptor units. The optical and electrochemical studies reveal that the new polymer (P) is a promising material for the development of polymer light emitting diodes (PLEDs).
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