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Two-Dimensional Conducting Polymers: Synthesis and Charge Transport
摘要： Current technological advances and prolific endeavors have entrenched two-dimensional conducting polymers as the rapidly emerging interface across a diversity of functional materials for flexible electronics, sensors, ion-exchange membranes, biotechnology, catalysis, energy storage, and conversion. Rational design and fabrication of polymeric nanostructures enriched with well-ordered geometry are appealing and endorse significant impact on their inbuilt electrical, optical, and mechanical properties. In particular, recent interest in controlled hierarchical assembly of monomers/oligomers proved the free-standing sheet-like structures with exotic features of high conductivity and flexibility. Yet, the ongoing research to make nanometer-thick polymers suffers from limitations to access large-area, mechanical stability, and high-range internal ordering. In this perspective, we focus on the radical approaches that highlight confinement-entitled features of two-dimensional polymeric materials correlating to their interface or template-assisted synthesis, structure–property relationship, charge transport properties, and future scopes for relevant practical enactments.
关键词： 2D assembly,self-organization,conjugated polymers,charge transport,interfacial synthesis
更新于2025-09-23 15:22:29
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Realizing efficient bipolar deep-blue light-emitting poly(2,7-carbazole) derivatives by suppressing intramolecular charge transfer
摘要： Two series of twisted bipolar poly(2,7-carbazole) derivatives, namely PCz-37RSOs and PCz-28SOs, were synthesized by introducing electron-deficient 2,8-dioctyl-dibenzothiophene-S,S-dioxide-3,7-diyl (37RSO) and dibenzothiophene-S,S-dioxide-2,8-diyl (28SO) unit into poly(9-heptadecanyl-2,7-carbazole) (PCz) backbone, respectively. The incorporation of electron-withdrawing 37RSO and 28SO into PCz backbone decreased effective conjugation length, and further restrained charge transfer effect existed in dipolar system, simultaneously, the balanced charge carrier injection/transportation were realized due to the electrophilicity of SO unit. Consequently, the resulting polymers showed hypsochromic shift and narrowed emission spectra regarding to PCz-37SOs that contains linear SO unit in main chain, and exhibited balanced hole/electron fluxes with respect to PCz in the range of 0–10 V. The single-layer devices based on resulting bipolar polymers exhibited excellent electroluminescent spectra stability in the current densities from 100 to 400 mA cm?2, and displayed deep blue electroluminescence spectra with the Commission Internationale de L’ Eclairage (CIE) of (0.16, 0.07) for PCz-37RSO5 and (0.16, 0.09) for PCz-28SO5. The superior device performance was achieved with the maximum luminous efficiency (LEmax) of 2.69 cd A?1 for PCz-28SO20, which obviously outperformed that of 0.24 cd A?1 for PCz. These results indicated that twisted molecular structure design is a promising strategy for efficient deep blue light-emitting polymers.
关键词： Poly(2,7-carbazole),Bipolar,Twisted structure,Blue light-emitting polymers,Charge transfer effect
更新于2025-09-23 15:22:29
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Impact of Alkyl Side Chain Length on Doping Kinetics, Thermopower and Charge Transport Properties in Highly Oriented F4TCNQ-Doped PBTTT films
摘要： Doping of polymer semiconductors such as PBTTT with acceptor molecules such as F4TCNQ is widely used to tune the charge transport and thermoelectric (TE) properties in thin films. However, the mechanism of dopant insertion in the polymer matrix, the insertion kinetics and the ultimate doping levels reached have been investigated only marginally. This contribution addresses the impact of alkyl side chain length on the doping mechanism of a series of PBTTTs with linear side chains ranging from n-octyl to n-octyldecyl. The study focuses on thin films oriented by high temperature rubbing and sequentially doped in F4TCNQ solution. Structure-property correlations are established as a function of side chain length by a combination of Transmission Electron Microscopy, polarized UV-Vis-NIR spectroscopy and charge transport / thermopower measurements. Intercalation of F4TCNQ into the layers of side chains results in the expansion of the lattice along the side chains and the contraction along the π-stacking direction for all polymers. The extent of lattice expansion decreases with increasing side chain length. UV-vis-NIR spectroscopy demonstrates integer charge transfer for all investigated PBTTTs. The doping kinetics and final doping level depend on both the side chain length and packing. Highly disordered n-octyl and crystalline n-octyldecyl side chain layers tend to hamper dopant diffusion in the side chain layers contrary to n-dodecyl side chains that can host the highest proportion of dopants. Consequently, the best TE properties are observed for C12-PBTTT films. Alignment of the polymers enhances significantly the TE performance by increasing the charge conductivity and the thermopower along the rubbing direction. Aligned films of C12-PBTTT show charge conductivities of 193 S/cm along the rubbing direction and power factors of approximately 100 μW.m-2.K-1 versus a few μW.m-2.K-1 for non-oriented films.
关键词： Thin films,Structure,Organic Thermoelectric,Conducting Polymers,Doping.
更新于2025-09-23 15:22:29
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Chemically Interconnected Thermotropic Polymers for Transparency-Tunable and Impact-Resistant Windows
摘要： Thermotropic polymers with the capability of thermally tuning transparency are widely applied in smart windows and energy-saving windows, playing a critical role in enhancing comfort level and energy efficiency of indoor spaces. Usually, thermotropic polymer systems are constructed by physically dispersing phase transition materials in transparent hosting materials. However, bad interfaces universally exist in these systems, resulting in poor mechanical properties, weak interfaces to substrates, or bad long-term stability. Herein, we demonstrate a novel chemically interconnected thermotropic polymer, which is obtained by reacting dodecanedioic acid (DDA) with glycerol. In the system, some of DDA molecules were crosslinked to form a polyester network, poly(glycerol-dodecanoate) (PGD). Other grafted but non-crosslinked DDA molecules form semi-crystalline domains which possess a solid-liquid phase transition within the PGD matrix. The phase transition offers the resulting hybrid materials with tunable optical transparency. The PGD-DDA system shows stable performance after 100 heating-cooling cycles. In addition, when applied for window coating, it results in tough interfacial bonding to glass substrates with toughness of > 6910 J m-2 below its transition temperature and > 135 J m-2 above its transition temperature. It increases the impact-resistance of the window by multiple times.
关键词： chemical interconnection,tough interfacial bonding,impact-resistant,smart windows,thermotropic polymers
更新于2025-09-23 15:22:29
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Agar-coated fiber Bragg grating sensor for relative humidity measurements: influence of coating thickness and polymer concentration nm
摘要： The importance of humidity control is spreading through a broad spectrum of applications, from food and pharmaceutical industries to biomedical and chemical fields. During the last decades, the growing interest in fiber Bragg gratings (FBG) led to new approaches and applications for the humidity measurement by means of the deposition of hygroscopic materials on gratings. The influence of the coating material and its features such us coating thickness (tk) and concentration (wt%) on static and dynamic metrological properties have been investigated in the literature. In this study, four agar-coated FBG sensors for humidity measurements have been fabricated, and the influence of tk and wt% on the sensors’ sensitivity and response time has been experimentally assessed. Sensitivity increases with tk and wt%: for instance, at 1 wt% it was 0.0024 nm·%-1 and 0.0052 nm·%-1 for tk=87 μm and tk=212 μm, respectively. Results showed that also the response time increased with tk and wt%: for instance, at 1 wt% it was 56.7 s and 107.6 s for tk=87 μm and tk=212 μm, respectively.
关键词： Moisture sensitive polymers,Hygroscopic materials,Relative humidity sensing,Fiber Bragg grating sensors,Fiber optic sensors
更新于2025-09-23 15:22:29
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Synthesis and Properties of Novel Thiophene-Based Liquid Crystalline Conducting Polymers
摘要： Side-chain liquid crystalline polythiophenes were synthesised and the effects of the mesogenic units on the structure and electronic properties of the polymers were studied. The liquid crystal properties of the polymer films were studied using polarised hot-stage optical microscopy and differential scanning calorimetry, and X-ray diffractometry was used to investigate the effect of a magnetic field on the monomers and polymers.
关键词： Polythiophene,Conducting polymers,Liquid crystals,X-ray diffraction,Magnetic field
更新于2025-09-23 15:22:29
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Ambipolar Conjugated Polymers with Ultrahigh Balanced Hole and Electron Mobility for Printed Organic Complementary Logic via a Two-Step C?H Activation Strategy
摘要： High mobility ambipolar conjugated polymers are seriously absent regardless their great potential for flexible and printed plastic devices and circuits. Here, ambipolar polymers with ultrahigh balanced hole and electron mobility are developed via a two-step C–H activation strategy. Diketopyrrolopyrrole-benzothiadiazole-diketopyrrolopyrrole (DBD) and its copolymers with thiophene/selenophene units (short as PDBD-T and PDBD-Se) are used as examples. PDBD-Se exhibits highly efficient ambipolar transport with hole and electron mobility up to 8.90 and 7.71 cm2 V?1 s?1 in flexible organic field-effect transistors, presenting a milestone for ambipolar copolymer screening. Based on this performance metrics and good solubility, PDBD-Se is investigated as inkjet-printable semiconductor ink for organic complementary logic circuits. Under ambient processing, maximum hole and electron mobilities reach 6.70 and 4.30 cm2 V?1 s?1, respectively. Printed complementary inverter and NAND gates with transition voltages near VDD/2 are fabricated, providing an easy-handling, general material for printed electronics and logic.
关键词： ambipolar transport,semiconducting polymers,organic circuits,inkjet printing,C–H activation
更新于2025-09-23 15:22:29
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Tuning Carbon Dots’ Optoelectronic Properties with Polymers
摘要： Due to their unique properties of photoluminescence, biocompatibility, photostability, ease of preparing, and low cost, carbon dots have been studied extensively over the last decade. Soon after their discovery, it was realized that their main optical attributes may be protected, enhanced, and tuned upon proper surface passivation or functionalization. Therefore, up to date, numerous polymers have been used for these purposes, resulting to higher-quality carbon dots regarding their quantum yield or further emission-related aspects and compared to the primitive, bare ones. Hence, this review aims to clarify the polymers’ role and effect on carbon dots and their features focusing on the quality characteristics of their photoluminescence upon passivation or functionalization. Given in fact the numbers of relevant publications, emphasis is given on recent articles capturing the latest advances for polymers in carbon dots for expanding emission lifetimes, advancing quantum yields, tuning emission wavelengths, enhancing specific spectral range absorption, and tailoring optoelectronic properties in general.
关键词： photoluminescence,functionalization,carbon dots,polymers,optoelectronic properties,surface passivation
更新于2025-09-23 15:22:29
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Polyacrylamide gel synthesis and photocatalytic performance of PbBiO2Br nanosheets
摘要： We designed and fabricated novel PbBiO2Br nanosheets via Polyacrylamide gel method. XRD, XPS, SEM, TEM and UV-vis absorption spectra were used to investigate the crystal microstructure, morphology, band-gap and optical properties of the as-prepared PbBiO2Br nanosheets. The photocatalytic performance and stability of PbBiO2Br nanosheets were evaluated by removing methylene blue (MB) aqueous solution (20 mg/L) under visible-light irradiation. Results showed that the PbBiO2Br was brick-like nanosheets with an average side size of about 80 nm and the absorption edge at about 500 nm, and exhibited an excellent photocatalytic performance under visible light irradiation. Moreover, the repeated cycle experimental results demonstrated that the PbBiO2Br nanosheets had a good chemical stability. Finally, the possible photocatalytic mechanism was proposed and discussed.
关键词： Semiconductor,PbBiO2Br,Polymers,Polyacrylamide gel,Photocatalysis
更新于2025-09-23 15:22:29
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Electrochromism: a fascinating branch of electrochemistry
摘要： This lecture on electrochromism and electrochromic devices starts with a short introduction to the field. This is followed by an overview of the different classes of electrochromic materials, in which each class is illustrated by some typical examples. The third part deals with some basic parameters to assess electrochromic compounds and devices. After this, we discuss the different types of electrochromic devices or elements, again always illustrated by some examples. Manufacturing considerations and real-world practical application examples of electrochromics are the topics of the last two parts of this lecture.
关键词： Electrochromic devices,Transition metal oxides,Electrochromism,Conducting polymers,Smart windows
更新于2025-09-23 15:21:21