Thiophene Content Research Articles

Randomly Distributed Conjugated Polymer Repeat Units for High-Efficiency Photovoltaic Materials with Enhanced Solubility and Processability.

Three structurally disordered terpolymer derivatives of PffBT4T-2OD (PCE11), prepared by replacing a varied amount of bithiophene linkers with single thiophenes, were found to exhibit reduced aggregation in solution with increasing thiophene content, while important redox and optoelectronic properties remained similar to those of PffBT4T-2OD. Solar cells based on random terpolymer-PC71BM blends exhibited average power conversion efficiencies of over 9.5% when processed with preheated substrates, with fill factors above 70%, exceeding those from PffBT4T-2OD. Thanks to increased solubility, random terpolymer devices were able to be fabricated on room-temperature substrates, reaching virtually identical performance among all three polymers despite remarkable thicknesses of ∼400 nm. Thus, we show that the random terpolymer approach is successful in improving processability while maintaining device performance.

Conjugated Microporous Polytetra(2‐Thienyl)ethylene as High Performance Anode Material for Lithium‐ and Sodium‐Ion Batteries

AbstractA novel, thiophene‐rich conjugated microporous polymer of polytetra(2‐thienyl)ethylene (PTTE) is synthesized via FeCl3‐catalyzed oxidative polymerization and applied as an anode material for lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). Owing to the high surface area, high redox‐active thiophene content, and the plentiful nanoporous structures in PTTE, the assembled LIBs exhibit a high specific capacitance of 973 mA h g−1 at 100 mA g−1 with excellent rate performance, and the SIBs show a capacitance as high as 370 mA h g−1 at a current density of 50 mA g−1, excellent rate capability, and outstanding cycling stability with a capacity retention of 230 mA h g−1 at 200 mA g−1 after 100 cycles. These results demonstrate this thiophene‐rich conjugated microporous polymer as a promising electrode material for next‐generation energy storage devices.

Effect of thiophene S on the enhanced ORR electrocatalytic performance of sulfur-doped graphene quantum dot/reduced graphene oxide nanocomposites.

In this study, a novel and simple hydrothermal method was developed to synthesize sulfur-doped graphene quantum dots (S-GQDs) with a diameter of 1–6 nm and S-GQD/reduced graphene oxide hybrids. The results indicated that an increase in the sulfur content led to superior ORR electrocatalytic activity. Moreover, it is found that thiophene S plays a significant role in the electrocatalytic activity. In addition, the average electron transfer number depends on the content of thiophene S. It is believed that the proposed synthesis strategy is a general and effective method for designing high-performance metal-free electrocatalytic materials.

Toward High Performance Thiophene‐Containing Conjugated Microporous Polymer Anodes for Lithium‐Ion Batteries through Structure Design

AbstractPoly(thiophene) as a kind of n‐doped conjugated polymer with reversible redox behavior can be employed as anode material for lithium‐ion batteries (LIBs). However, the low redox activity and poor rate performance for the poly(thiophene)‐based anodes limit its further development. Herein, a structure‐design strategy is reported for thiophene‐containing conjugated microporous polymers (CMPs) with extraordinary electrochemical performance as anode materials in LIBs. The comparative study on the electrochemical performance of the structure‐designed thiophene‐containing CMPs reveals that high redox‐active thiophene content, highly crosslinked porous structure, and improved surface area play significant roles for enhancing electrochemical performances of the resulting CMPs. The all‐thiophene‐based polymer of poly(3,3′‐bithiophene) with crosslinked structure and a high surface area of 696 m2 g−1 exhibits a discharge capacity of as high as 1215 mAh g−1 at 45 mA g−1, excellent rate capability, and outstanding cycling stability with a capacity retention of 663 mAh g−1 at 500 mA g−1 after 1000 cycles. The structure–performance relationships revealed in this work offer a fundamental understanding in the rational design of CMPs anode materials for high performance LIBs.

N-methyl-2-pyrrolidone/CS2 extraction induced changes in surface and bulk structures of a lignite

Investigation on the changes in detailed surface and bulk structures during N-methyl-2-pyrrolidone/CS2 mixed solvent extraction is crucial to improve and develop the technology of clean and value-added utilization of coals. The surface and bulk structures of Longkou lignite (LL) were investigated before and after ultrasonic-assisted extraction with mixed solvent by multiple direct tools, including, Fourier transform infrared (FTIR) spectrometer, X-ray photoelectron spectrometer (XPS), scanning electron microscope (SEM), and solid-state 13C nuclear magnetic resonance (NMR). The results show that phenols, alcohols, and ethers are the main C–O bond containing species in LL, which is further confirmed by 13C NMR and XPS analyses. The average ring number in each aromatic cluster and substituents in each aromatic ring are 4 and 2–3, respectively. XPS analysis shows that pyrrolic nitrogen is the main nitrogen occurrence and sulfur is mainly present in sulfoxide and sulfone in LL. 13C NMR and FTIR analyses all reveal that aromaticity and aromatic cluster size for LL decreased, while the length and the number of substituents on aromatics increased after extraction. C–O and multi-substituted aliphatic carbons are not easy to dissolve and concentrate in extract residue. It is the basic pyridine-N rather than pyrrolic-N species that are easy to extract with mixed solvent. The content of thiophene-S increased significantly, while other organic sulfur species decreased after extraction, especially for thiophenol and sulfone. Furthermore, solvent extraction leads to the reduction of particle size and increase of surface roughness of LL.

Enhanced desulfurization performance and stability of Pebax membrane by incorporating Cu+ and Fe2+ ions co-impregnated carbon nitride

In this study, Cu+ and Fe2+ ions were co-impregnated onto carbon nitride nanosheets via polydopamine chelating, and then incorporated into a Pebax matrix to fabricate the facilitated transport hybrid membranes. The homogeneously dispersed nanosheets disturb the packing of Pebax chains and render the hybrid membrane an appropriate free volume property. The existence of stabilizer Fe2+ on Cu+Fe2+@CNs prevents the disproportionation and oxidation of Cu+, which is an efficient facilitated transport carrier for thiophene via π-complexation in gasoline desulfurization. Accordingly, the hybrid membranes exhibit superior desulfurization performance along with good stability even at high operation temperature. Especially, when the content of Cu+Fe2+@CNs is 5wt%, the membrane achieves the optimum desulfurization performance with a permeation flux of 13.42kg/(m2h) (18.76% higher than that of pure Pebax membrane) and an enrichment factor of 7.11 (28.80% higher than that of pure Pebax membrane) under 60°C for octane-thiophene model gasoline with thiophene content of 1312ppm. Besides, the membrane shows good stability in the long-term desulfurization under high operation temperature of 60°C for 10 days and keeps the stability of incorporated Cu+ for six months. The study offers a facile approach to enhance the carrier stability in high-performance facilitated transport membranes.

Thermochemical processing of high-sulfur Israeli shale

The thermochemical processing of high-sulfur shale from the Mishor Rotem deposit (Israel) is studied in terms of the material balance, in a Fisher retort and a larger-scale laboratory system. The properties of the products (tar, char, and gas) are determined. The shale tar has a high sulfur content, on account of the presence of a wide range of thiophene derivatives. In the fractions of semicoking tar from Mishor Rotem shale that boil at temperatures up to 250°C, 236 compounds are quantitatively identified. The content of thiophene and its homologs with the substituents C1–C5 and of benzothiophene with alkyl substituents C1–C3 is determined.

Synthesis, structures, and density functional theory computational study of thiophene‐containing and fluorodecorated imine‐linked polymers

ABSTRACTA new series of extended–conjugated and thermally stable thiophene‐containing imine‐linked polymers were synthesized via a Schiff‐base condensation reaction between aryl aldehydes and 2,6‐diaminopyridine building blocks. The backbones of the polymers were functionalized with phenyl, fluorosubstituted phenyl, thienyl, and pyridyl aromatic rings. The successful synthesis was confirmed with spectrochemical characterization techniques, including IR, 1H‐NMR, 13C‐NMR, and elemental analyses. The electronic properties of the polymers were investigated with ultraviolet–visible (UV–vis) absorption spectroscopy; the properties were collected experimentally and calculated with density functional theory (DFT) in the gas phase. The maximum absorption calculated from DFT was higher than the experimental values by about 60 nm; this was attributed to the absence of the solvent effect in the DFT case. The frontier molecular orbital ((HOMO) highest occupied molecular orbital and (LUMO) lowest unoccupied molecular orbital), optical band gap (Eg), and total energy (ET) values of the optimized structures were calculated. Apparently, there was a significant relation between the number of thiophene rings and the resulting Eg and ET values. As the number of thiophene rings in the polymer chain increased, Eg and ET decreased, and the thermal stability of the polymers increased. Eg and the absorption band edges were determined experimentally from the UV–vis and transmittance spectra, respectively. Poly(terthienyl–azomethine–pyridine–azomethine), with the highest thiophene content, had the lowest experimental and calculated Eg values (2.10 and 2.63 eV, respectively). In contrast, upon fluorination, poly[(2,5‐dithienyl–1,4‐difluorobenzene)–azomethine–pyridine–azomethine] exhibited the highest Eg (2.81 eV) and absorption band edges (2.94 eV), whereas the thermal stability decreased to 250 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44331.

English

Marigold (Tagetes spp.) is a source of thiophenes, which are a group of heterocyclic sulfurous compounds possessing strong biocidal activity, thus making Tagetes plants very useful as natural source of agents for controlling pathogens such as nematodes, insects, fungi and bacteria. Hairy root cultures of Tagetes erecta L. were developed using Agrobacterium rhizogenes mediated transformation. The hairy root clones showed great variations in growth pattern and total thiophene content (0.31 to 0.96 mg/gfw). Four types of thiophenes that accumulated in root cultures of Tagetes were butenenylbithiophene (BBT), hydroxybutenenylbithiophene (BBTOH), acetoxybutenenylbithiophene (BBTOAc) and α-terthienyl (α-T). Total thiophene contents in these isolated rhizoclones were found tobe four fold higher than that of wild type hairy root cultures. The developed method of producing hairy cultures of T. erecta can be used for producing thiophenes at large scale. Key words : Agrobacterium rhizogenes , marigold, rhizoclones, biocidal.

Polydimethyl siloxane–graphene nanosheets hybrid membranes with enhanced pervaporative desulfurization performance

A series of polydimethyl siloxane-graphene nanosheets (PDMS-GNS) hybrid membranes were fabricated via physically blending method. In these hybrid membranes, GNS exhibit different orientation and dispersity with the variation of GNS content. An appropriate interfacial structure favoring permeate molecules transport is constructed, which mainly arises from the non-covalent interactions between PDMS and GNS. The mechanical stability, thermal stability and anti-swelling property of the hybrid membranes are simultaneously enhanced. Pervaporative desulfurization performance of PDMS-GNS/PVDE hybrid membranes was investigated utilizing n-octane/thiophene mixture as a model gasoline system. The prepared hybrid membranes show an enhanced permeation flux while maintaining a constant enrichment factor, which should be attributed to the optimized free volume characteristics of the membranes and pi-pi interactions between GNS and thiophene. Especially, when GNS/PDMS mass ratio reaches 0.2 wt%, the membrane shows an optimum desulfurization performance with a permeation flux of 622 kg/(m(2) h) (65.9% higher than that of pure PDMS membrane) and an enrichment factor of 3.58 (similar to that of pure PDMS membrane). Additionally, the effects of GNS content, operation temperature, thiophene content, feed Row rate and operation time on membrane separation performance were investigated systematically. The prepared hybrid membranes may find potential applications in the separation of aromatics-containing mixtures. (C) 2015 Elsevier B.V. All rights reserved.

A Timely Synthetic Tailoring of Biaxially Extended Thienylenevinylene‐Like Polymers for Systematic Investigation on Field‐Effect Transistors

Considering there is growing interest in the superior charge transport in the (E)‐2‐(2‐(thiophen‐2‐yl)‐vinyl)thiophene (TVT)‐based polymer family, an essential step forward is to provide a deep and comprehensive understanding of the structure–property relationships with their polymer analogs. Herein, a carefully chosen set of DPP‐TVT‐n polymers are reported here, involving TVT and diketopyrrolopyrrole (DPP) units that are constructed in combination with varying thiophene content in the repeat units, where n is the number of thiophene spacer units. Their OFET characteristics demonstrate ambipolar behavior; in particular, with DPP‐TVT‐0 a nearly balanced hole and electron transport are observed. Interestingly, the majority of the charge‐transport properties changed from ambipolar to p‐type dominant, together with the enhanced hole mobilities, as the electron‐donating thiophene spacers are introduced. Although both the lamellar d‐spacings and π‐stacking distances of DPP‐TVT‐n decreased with as the number of thiophene spacers increased, DPP‐TVT‐1 clearly shows the highest hole mobility (up to 2.96 cm2 V−1 s−1) owing to the unique structural conformations derived from its smaller paracrystalline distortion parameter and narrower plane distribution relative to the others. These in‐depth studies should uncover the underlying structure–property relationships in a relevant class of TVT‐like semiconductors, shedding light on the future design of top‐performing semiconducting polymers.

Simple Model for Predicting the Cutting Temperature between Light and Heavy Fractions in Fluid Catalytic Cracking Naphtha Selective Hydrodesulfurization Processes

In selective hydrodesulfurization processes for hydro-upgrading fluid catalytic cracking (FCC) naphtha with high olefin and sulfur contents, it is a common practice to split the feeding full-range FCC naphtha into a light fraction and a heavy fraction. This operation can effectively alleviate olefin saturation and thereby octane loss. Thus, the determination of a suitable cutting temperature plays a vital role in guaranteeing the success of the operation. Starting by fractionating two FCC naphthas into nine narrow cuts, this paper shows that, despite the great differences in the properties of the two FCC naphthas, both hydrocarbons and sulfides have almost the same distributions in the nine cuts. More importantly, it was observed that the distribution of sulfides in the narrow cuts is irrelevant to their true boiling points because of the formation of azeotropes between sulfides and hydrocarbons. On the basis of these findings, a simple model for estimating thiophene content in light FCC naphtha and, ther...

Intrinsic Kinetics of Coking Crude Benzene Hydrodesulfurization on a Ti Modified Co-Mo-P/γ-Al<sub>2</sub>O<sub>3</sub> Catalyst

With different content of thiophene in coking crude benzene, the Orthogonal design experiments of thiophene hydrodesulfurization on a Ti modified Co-Mo-P/γ-Al2O3 catalyst were carried out in a micro-reactor under the reaction conditions of 2.3~2.7MPa,275~335°C, 0.5h-1LHSV and H2/Oil 600~750. The kinetic parameters and the intrinsic kinetics were acquired by 4-order Runge-Kutta method and the modified Simplex method. The power-law type kinetic model was established and consistent with the experiment data and highly acceptable and reliable.

Spatial and temporal dynamics of root exudation: how important is heterogeneity in allelopathic interactions?

Understanding allelopathy has been hindered by the lack of methods available to monitor the dynamics of allelochemicals in the soil. Previous work has demonstrated the feasibility of using polydimethylsiloxane (PDMS) microtubing (silicone tubing microextraction, or STME) to construct sampling devices to monitor the release of lipophilic allelochemicals from plant roots. The objective of this study was to use such sampling devices to intensively monitor thiophene fluxes beneath marigolds over several weeks to gain insight into the magnitude of temporal and spatial heterogeneity in these fluxes. Marigolds were grown in rhizoboxes (20.5 x 20.5 x 3.0 cm) with 16 individual STME samplers per box. Thiophene sampling and HPLC analysis began 45 days after planting. At the end of the study, roots around each sampler were analyzed by HPLC. Results confirmed the tremendous spatial and temporal heterogeneity in thiophene production seen in our previous studies. STME probes show that thiophene concentrations generally increase over time; however, these effects were sampling-port specific. When sampling ports were monitored at 12 h intervals, fluxes at each port ranged from 0 to 2,510 ng day(-1). Fluxes measured over daylight hr averaged 29 % higher than those measured overnight. Fluxes were less than 1 % on average of the total thiophene content of surrounding roots. While the importance of such heterogeneity, or "patchiness", in the root zone has been recognized for soil nutrients, the potential importance in allelopathic interactions has seldom been considered. The reasons for this variability are unclear, but are being investigated. Our results demonstrate that STME can be used as a tool to provide a more finely-resolved picture of allelochemical dynamics in the root zone than has previously been available.

Advanced oxygen reduction reaction catalyst based on nitrogen and sulfur co-doped graphene in alkaline medium.

A novel nitrogen and sulfur co-doped graphene (N-S-G) catalyst for oxygen reduction reaction (ORR) has been prepared by pyrolysing graphite oxide and poly[3-amino-5-mercapto-1,2,4-triazole] composite (PAMTa). The atomic percentage of nitrogen and sulfur for the prepared N-S-G can be adjusted by controlling the pyrolysis temperature. Furthermore, the catalyst pyrolysed at 1000 °C, denoted N-S-G 1000, exhibits the highest catalytic activity for ORR, which displays the highest content of graphitic-N and thiophene-S among all the pyrolysed samples. The electrocatalytic performance of N-S-G 1000 is significantly better than that of PAMTa and reduced graphite oxide composite. Remarkably, the N-S-G 1000 catalyst is comparable with Pt/C in terms of the onset and half-wave potentials, and displays larger kinetic limiting current density and better methanol tolerance and stability than Pt/C for ORR in an alkaline medium.

Space-Charge-Limited Bipolar Currents at High Fields in Polymer/C<sub>60</sub> Diodes: A Simple Model Description

We investigate the dark transport properties of organic photovoltaic devices formed by a heterojunction of a semiconducting co-polymer and the fullerene (C60) [. The copolymers are composed of thiophene, phenylene and fluorene units, where the thiophene content was kept constant while the fluorene/phenylene ratio was varied. Measurements show that for low voltage, the current versus voltage (j x V) characteristics presents an exponential increasing, typical of a diode behavior. On the other hand, the j x V curves are space-charge limited at high voltages. This latter response follows the theoretical predictions proposed by Koehler et al in Ref. [ (see also [), which explains the dark current in polymer/fullerene photodiodes at high V's. To describe the full j x V characteristics, we have extended the analysis in Ref. [ assuming a space-charge dependent inner series resistance. From such model we are able to nicely fit the experimental curves, to estimate the effective mobility in the whole device and to obtain the diode reverse saturation current j0. Finally, the results indicate that the copolymer with the highest effective total mobility is the PFT [(9,9dihexyl-9H-fluorene-2,7-diyl)-1,2-ethenediyl-2,5-thiophene-1,2ethenediy.

Removal of Thiophene from Binary Mixtures Using Polyether Block Amide (PEBAX) Film by Pervaporation

Reduction of organosulfurs in gasoline has become an urgent requirement in the world, especially in China. The goal of this work focuses on removal of thiophene from binary mixtures of thiophene and n-heptane by means of pervaporation. The PEBAX homogenous film was prepared by coating. The swelling experiments of film were studied for the affinity of PEBAX film to thiophene. The swelling degree of film increased with increasing thiophene content in the mixtures. The result indicates the PEBAX film had preferential sorption to thiophene rather than n-heptane. Pervaporation experiments were studied for investigating separation properties of the film. The effect of thiophene concentration in feed and operation temperature on separation properties of the film was researched. The results of pervaporation showed that both total and thiophene flux increased with increase of thiophene content in the feed and temperature, but the separation factor deceased with their increase. The activity energy was calculated according to the Arrhenius relationship. This work may offer useful visions into the possibility of the separation of sulfur compounds from gasoline via pervaporation.

The current-voltage characteristics of polymer/C60 diodes in the dark: A direct way to assess photovoltaic devices efficiency parameters

A general description of dark transport properties in bi-layer organic photovoltaic devices formed by a heterojunction of a semiconducting co-polymer and fullerene (C60) is presented. The copolymers are composed of thiophene, phenylene, and fluorene units, where the thiophene content is kept constant while the fluorene/phenylene ratio is varied. Measurements show that the j × V characteristics display typical diode behavior (exponential increasing) at low and are space-charge limited at high voltages. Extending a theoretical analysis by Koehler et al. [J. Appl. Phys. 92, 5575 (2002)], a model which assumes a space-charge dependent inner series resistance—attributed to molecular and morphological aspects of the materials—is proposed. It turns out to be general and able to nicely fit the experimental curves for all the studied samples. Furthermore, the model quantifies relevant parameters (the effective mobility and the diode reverse saturation current j0) which will determine the systems efficiency. The framework hence allows to foremost the devices functioning under illumination from direct experiments of the active material in the dark.

Novel BN porous-hollow nanorods: synthesis, tunable dimensions, property and formation mechanism

In this paper, we used a high pressure benzene-thermal method to successfully prepare novel BN porous-hollow nanorods. Herein, thiophene is introduced as a catalyst to eliminate the benzene carbonization at high temperature. The alveolate porous wall of the nanorods is stacked up by small nanoflakes aligned vertically in the axial direction. In the high pressure solvothermal system, the diameter and wall thickness of the nanorods can be simply adjusted by the content of thiophene, temperature and pressure. A possible “gas–liquid–solid” mechanism is proposed to explain the formation of 1D BN nanorods. Another novel formation mechanism of the hollow nanorods is elaborated by observing the evolution process of the porous-hollow nanostructures. The method may provide a new idea to be used in preparing other porous-hollow nanostructures. In addition, the hierarchical porous-hollow nanorods exhibit an excellent hydrogen uptake property of 2.6 wt% at 298 K and 90 bar. In particular, the adsorption capacity per unit specific surface area was calculated to be 2.2 × 10−2 wt% m−2 g. This is a rather high value of hydrogen adsorption capacity for BN nanomaterials.

Larvicidal Activity of Tagetes erecta Against Aedes aegypti

The aim of this study was to evaluate the activity of essential oil from Tagetes erecta against 3rd instars of Aedes aegypti and to determine the amounts of larvicidal thiophenes in all plant tissues. The oil obtained by steam distillation and analyzed by gas chromatography/mass spectrometry showed 14 compounds. The main compounds were piperitone (45.72%), D-limonene (9.67%), and piperitenone (5.89%). The essential oil was active against larvae of Ae. aegypti, with LC50 of 79.78 microg/ml and LC90 of 100.84 microg/ml. The larvicidal thiophene contents were higher in the roots and flowers as demonstrated by high-performance liquid chromatography analysis. Thus, T. erecta constitutes a good source of varied compounds showing larvicidal activity against Ae. aegypti.