Adsorption kinetics and equilibrium of copper from ethanol fuel on silica-gel functionalized with amino-terminated dendrimer-like polyamidoamine polymers

The adsorption kinetics and equilibrium of silica-gel functionalized with amino-terminated dendrimer-like polyamidoamine (PAMAM) polymers SiO₂-G1.0, SiO₂-G2.0 and SiO₂-G3.0 for Cu²⁺ in ethanol fuel were investigated by using batch method. The results indicated that the all the adsorptions of the three adsorbents followed well the pseudo second-order model. The adsorption isotherms were fitted by Langmuir model, Freundlich model and Dubinin–Radushkevich (D–R) model. The results showed that Langmuir model was more suitable to describe the equilibrium data than the Freundlich model. From the D–R isotherm model, the mean free energy E calculated of the three adsorbents showed that the adsorptions were taken place by physical processes. Thermodynamic parameters, ΔG⁰, ΔH⁰ and ΔS⁰ indicated the Cu²⁺ adsorption to be endothermic and spontaneous with decreased randomness at the solid-solution interface, resulting in their higher adsorption capacities at higher temperature. The effect of generation number of PAMAM polymers loaded on silica-gel, contact time, initial concentration and temperatures on the adsorption capabilities were studied in detail. Moreover, the adsorption mechanism of copper from ethanol fuel was also presumed.     

Synthesis and characterization of thieno[3,4-c]pyrrole-4,6-dione and pyrrolo[3,4-c]pyrrole-1,4-dione-based random polymers for photovoltaic applications

New random poly{benzo[1,2-b:4,5-b']dithiophene-thieno[3,4-c]pyrrole-4,6-dione-pyrrolo[3,4-c]pyrrole-1,4-dione} (PBDT-TPD-DPP) based on benzo[1,2-b:4,5-b']dithiophene (BDT) as donor and thieno[3,4-c]pyrrole-4,6-dione (TPD, 60–90%), pyrrolo[3,4-c]pyrrole-1,4-dione (DPP, 10–40%) as acceptors were synthesized through Stille coupling reaction. The photophysical, electrochemical and photovoltaic properties of random polymers were investigated. The random polymers with high molecular weight (M_n = 33.5–41.7 kDa) exhibited broad and strong absorption covering the spectra range from 350 nm up to 922 nm with absorption maxima at around 700 nm, the relatively deep highest occupied molecular orbital (HOMO) energy levels vary between ?5.25 and ?5.42 eV and suitable lowest unoccupied molecular orbital (LUMO) energy levels ranging from ?3.85 to ?3.91 eV. Polymer solar cells (PSC) based on these new random polymers were fabricated with device structures of ITO/PEDOT: PSS/random polymers: PC₇₁BM (1:2, w/w)/Ca/Al. The photovoltaic properties of random polymers were evaluated under AM 1.5G illumination (100 mW/cm²). Devices based on the random polymers showed open circuit voltage (V_oc) of 0.71–0.83 V, and power conversion efficiency (PCE) of 0.82–1.80%.     

Synthesis of fluorene- and anthracene-based π-conjugated polymers and dependence of emission range and luminous efficiency on molecular weight

In the present work poly[9,9-dioctylfluorene-co-2-pentyl-9,10-bis(4-vinylphenyl)anthracene], a fluorene- and anthracene-based copolymer, is synthesized through a Heck coupling reaction. In order to synthesize polymers with high-molecular weight, DMF (P1), DMF/p-Xylene = 1/1 (P2), p-Xylene (P3), and 1,4-Dioxane (P4) are used as solvents, which are an important factor in the synthesis process. The number of average molecular weights (M_n) of the synthesized polymers P1–P4 do not differ significantly, standing at 22,309, 12,369, 29,192, and 39,464, respectively, while their weight average molecular weights (M_w) show considerable differences (i.e. 50,055; 24,042; 125,406; and 231,053). Polymers P1–P4 demonstrate little difference in the results of a thermal analysis, electrochemical analysis, UV–vis analysis, and photoluminescence (PL) spectrum measurement. With regard to electroluminescence (EL) spectrum measurement, however, P1 and P2 show main luminous peaks at 508 nm, while P3 and P4's luminous peaks are seen at 516 nm. Moreover, luminous shoulder peaks were red-shifted with increase of molecular weight of polymers from 460 to 544 nm. In this process, the luminous area is red-shifted from greenish-blue to yellowish-green. The I–V–L measurement results show that the maximum brightness of P1, P2, and P3 ranges from 164 to 303 cd/m² and their luminous efficiency is low at 0.031–0.054 cd/A. Meanwhile, the turn-on voltage of P4, having greater molecular weight, is 9.5 V, and its maximum brightness and corresponding luminous efficiency are 736 cd/m² and 0.08 cd/A, respectively, implying that the luminous efficiency of devices improves as the molecular weight becomes greater.     

Optical,electrochemical, and photovoltaic properties of conjugated polymers with dithiafulvalene as side chains

Three conjugated polymers, P1–P3, with dithiafulvalene (DTF) as side chains have been synthesized. All polymers have good thermal stabilities. The DTF unit could be oxidized to DTF?⁺ which was observed from cyclic voltammetry and ultraviolet–visible (UV–vis) spectra, and the oxidation process was independent of the conjugated backbone of the polymer. The strong π–π* transition absorbing band of the three polymers decreases gradually as increasing oxidation, and the resulting DTF?⁺ species give rise to an additional band at 750–1100 nm, which can be assigned to a distinguishing feature of the cation radical species. Photovoltaic device based on the blend of P2 and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC₆₁BM) showed the power conversion efficiency of 1.05% with a fill factor of 42.8%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41508.     

Synthesis and light emitting properties of sulfide-containing polyfluorenes and their nanocomposites with CdSe nanocrystals: A simple process to suppress keto-defect

A new series of sulfide-containing polyfluorene homopolymers and copolymers (PFS, PF1, PF3 and PF4) comprising 9,9-di[11-(decylsulfanyl)undecyl] fluorene, 9,9-dihexylfluorene, triphenylamine or benzothiadiazole moieties were synthesized by Ni(0)-mediated Yamamoto-coupling and palladium-catalyzed Suzuki polymerizations. Three other polyfluorenes (PF2, PF5 and PFC6) without sulfur atom in the alkyl side chains were also synthesized by a similar method for comparison purpose. These fluorene-based polymers were characterized using FT-IR spectroscopy, elemental analysis, DSC, TGA, photoluminescence (PL) and electroluminescence (EL) spectroscopies. The synthesized polymers PFS and PF1–PF3 emit blue light at around 440–468 nm, while copolymers PF4 and PF5 emit green light at around 540 nm. In annealing experiments, these polymer films show better stability against thermal oxidation than polymer PFC6. Sulfide-containing polymers show not only good electroluminescent color stability, but their EL spectra also remain unchanged at high driving voltage. A multi-layer electroluminescent device with the configuration of ITO/PEDOT/PF1/CsF/Al exhibited a stable sky-blue emission with color coordinates (0.21, 0.23) at 10 V, which showed a maximum brightness of 2991 cd/m² at 8 V (75 mA/cm²) and a maximum efficiency of 1.36 cd/A. Finally, by ligand exchange process, the sulfur element could form coordination bonding with quantum dots, and PLED devices using these new QDs-containing organic/inorganic hybrid materials as light-emitting layers exhibit superior or comparable EL performance compared to those without quantum dots.     

Flexible Metal‐Free Memory Electronic Made of π‐Conjugation‐Interrupted Hyperbranched Polymer Switch and Reduced Graphene Oxide Electrodes

A flexible metal‐free flash memory device with reduced graphene oxide films as electrodes and diarylfluorene‐based π‐conjugation‐interrupted hyperbranched polymers (CIHPs) as active switches is reported. Two CIHPs, named PCzPF and PCzPF‐PF, are synthesized via BF₃?Et₂O‐catalyzed fluorenol’s Friedel–Crafts reaction, where the PCzPF‐PF is designed by the decoration of hindrance functional groups, i.e., bulky 9‐phenyl‐fluorenyl (PF) moieties, at the end‐groups of PCzPF. Both of the two CIHPs exhibit excellent solubility and thermal stability. The PCzPF‐based device exhibits no switching effect while the PCzPF‐PF‐based device shows a flash type memory effect, indicating the incorporation of PF groups plays a critical role in realizing electrically bistable behaviors. In particular, the optimized memory exhibits a high ON/OFF ratio of > 3.0 × 10³, long retention time of up to 1.2 × 10⁴ s, and high mechanical stability. This work opens a new avenue for metal‐free memory electronics through a low‐cost and full‐solution process approach.     

Synthesis of copolyfluorenes with high fluorenone contents and its application in electroluminescent device by simple blending

Poly(fluorene‐co‐fluorenone)s containing high contents of fluorenone chromophore were synthesized by the Suzuki coupling reaction to study their electroluminescent (EL) properties. The copolymers are thermally stable below 430°C (T_d) in nitrogen atmosphere. In film state, their absorption and photoluminescence spectra (peaked at 373–382 nm and 562–564 nm, respectively) are mainly originated from fluorenone units, because of its efficient energy transfer. Both LUMO and HOMO energy levels, estimated from their cyclic voltammograms, are lowered slightly (−3.17→−3.23 eV, −5.84→−5.89 eV) with increasing contents of electron‐withdrawing fluorenone units. Double‐layer EL devices, using the copolyfluorenes or their blends with poly(9,9‐dihexylfluorene) ( PF ) as emitting layer, show exclusive emission originated from fluorenone chromophore (565 nm) when its content is high. Blending 0.02–5 wt % of PF‐33 (fluorenone fraction: 0.37) with PF greatly enhances device performance (610 cd m⁻² → 4400 cd m⁻² and 0.45 cd A⁻¹ → 1.52 cd A⁻¹). Our results demonstrate that the copolyfluorenes are promising emitting materials for EL devices by simple blending. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Donor-acceptor copolymer based on dioctylporphyrin: Synthesis and application in organic field-effect transistors

A novel alternating D–A copolymer, PPor–BT, with dioctylporphyrin (Por) as a donor unit and 5,6-bis(octyloxy)benzo-2,1,3-thiadiazole (BT) as an acceptor unit, was designed and synthesized by Pd-catalyzed Sonogashira-coupling reaction. The copolymer showed good solubility and film-forming ability. PPor–BT exhibited a broad absorption band from 350 to 950 nm with two peaks centered at 456 and 818 nm corresponding to the Soret band and Q-bands absorption of porphyrin segments, respectively. The employment of electron deficient BT unit to construct donor-acceptor structure observably broadened the absorption spectrum and enhanced the Q-band absorption of the porphyrin-based polymer. The HOMO and LUMO energy levels of the polymer are ?5.06 eV and ?3.63 eV, respectively. The solution-processed organic field-effect transistors (OFETs) were fabricated with bottom gate/top-contact geometry. The mobility of PPor–BT based OFEFs reached 4.3 × 10^?5 cm² V^?1 s^?1 with an on/off current ratio of 10⁴. This mobility is among the highest values for porphyrin-based polymers.     

Enhancement in thermoelectric properties using a P‐type and N‐type thin‐film device structure

In this study, we have fabricated thermoelectric devices with p‐type and n‐type conducting polymers and research the effect of device structure with the thermoelectric properties. It was found that the p‐type and n‐type structure greatly enhances the device's electrical conductivity due to separated charge carrier channels, but the Seebeck coefficient was reduced due to the increase of charge density by doping. Photoexcitation can improve the device's thermoelectric properties and can increase the Seebeck coefficient and electrical conductivity with increasing doping concentration simultaneously. The increases in both properties are due to the phonon–electron coupling effect: the concentration of electrons and holes are increased under illumination, and the phonon component of the heat flux can be reduced by phonon scattering. Consequently, the thermoelectric device structure can improve the efficiency of thermoelectric conversion. The P3HT:PCBM devices demonstrate a significant enhancement in the power factor (PF = S²σ), with a maximum value of ZT = 0.5 at 147°C, in which the PF value (34.8 μV/cm K²) is bigger than Bi₂Te₃/Sb₂Te₃ superlattice devices at room temperature. POLYM. COMPOS., 34:1728–1734, 2013. © 2013 Society of Plastics Engineers     

Synthesis,properties, and self‐assembly of poly(benzyl ether)‐b‐polystyrene dendritic–linear polymers

Poly(benzyl ether)‐b‐polystyrene dendritic–linear polymers were successfully synthesized using a dendritic chloric poly(benzyl ether) (G₁‐Cl, G₂‐Cl, and G₃‐Cl) as the macroinitiator through the atom transfer radical polymerization process. The structure and properties of the resultant polymers were characterizated by gel permeation chromatography, ¹H‐NMR, Fourier transform IR, thermogravimetric analysis, and differential scanning calorimetry. It was found that the temperature, reaction time, molar ratio of the macroinitiator to styrene, and the generation number of the macroinitiator have significant effects on the molecular weights, conversion, and polydispersities of the resulting polymers. These dendritic–linear block polymers had very good solubility in common organic solvents at room temperature. The terminal group (dendritic segments) of the polymers can affect their thermal stability. These dendritic–linear polymers after self‐assembling in selective solvents (chloroform/acetone) formed core–shell micelles. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1106–1112, 2005     

Structure,Judd-Ofelt analysis and spectra studies of Sm3+-doped MO-ZnO-B2O3–P2O5 (M = Mg,Ca, Sr,Ba) glasses for reddish-orange light application

In the present work, a series of Sm³⁺-doped MO-ZnO-B₂O₃–P₂O₅ (M = Mg, Ca, Sr, Ba) glasses were prepared. The glass structure and luminescence properties were investigated by XRD, DSC, IR, absorption spectroscopy, Judd-Ofelt theory and photoluminescence spectra. The J-O parameters of Sm³⁺-doped glasses follow the trend of Ω₄＞Ω₆＞Ω₂. Under the excitation of 401 nm Xenon lamp, Sm³⁺-doped glasses exhibited four emissions from the transitions of ⁴G_5/2→⁶H_J/2 (J = 5, 7, 9, 11) in the visible spectra. The luminous intensity of Sm³⁺ increases with the asymmetry in local environments and decreases with the increasing radius of the alkaline-earth cation. Among the as-prepared glass, the Sm³⁺-doped glass containing magnesium oxide exhibits higher values of stimulated emission cross-section (2.18 × 10⁻²¹ cm²), gain bandwidth (1.40 × 10⁻²⁷ cm³), and optical gain (3.83 × 10⁻²⁴ cm²). All the Sm³⁺-doped glasses show intense orange light in the CIE 1931 chromaticity diagram with a high color purity exceeding 99%. In addition, the time-resolved emission spectra reveal the decay process of the Sm³⁺ ions for the transitions ⁴G_5/2 → ⁶H_7/2 and ⁴G_5/2 → ⁶H_9/2 in the glass containing magnesium oxide. It suggests that Sm³⁺-doped alkaline-earth zinc borophosphate glasses could be a potential candidate for reddish-orange light-conversion fluorescent materials based on the ultraviolet light-emitting diode.     

Synthesis and characterization of donor-acceptor type 4,4′-bis(2,1,3-benzothiadiazole)-based copolymers

A series of novel donor-acceptor type polymers based on 4,4′-bis(2,1,3-benzothiadiazole) were synthesized and characterized. Two soluble regioregular tail-to-tail and head-to-head coupled polymers, poly[7,7′-bis(3-octyl-2-thienyl)-4,4′-bis(2,1,3-benzothiadiazole)] poly[3TBB3T], and poly[7,7′-bis(4-octyl-2-thienyl)-4,4′-bis(2,1,3-benzothiadiazole)] poly[4TBB4T] were synthesized by FeCl₃-mediated oxidative polymerization. To further decrease the band gap of the polymers, vinylene spacers were incorporated into the polymer backbone by Stille coupling of the corresponding monomers and (E)-1,2-bis(tributylstannyl)ethene. A crystal structure of a monomer analog shows near planar arrangement of the aromatic units in the solid state. The optical properties of the monomers and polymers were investigated by steady-state absorption and photoluminescence spectroscopy. Cyclic voltammetry measurements indicate that the polymers could be employed as acceptor materials in polymer-polymer bulk heterojunction solar cells due to their low LUMO energy of about −4.0 eV. A maximum photovoltaic power conversion efficiency of about 0.3% was observed for a 1:1 blend of regioregular poly(3-hexylthiophene) (rr-P3HT) and poly[4TBB4T] and the origin of the moderate efficiency is discussed by interpreting the device current-voltage characteristics, external quantum efficiency and incident light intensity dependence of the power conversion efficiency.     

The Investigations of the Pr,Gd, Si–N Doping,and Phosphor Curvature Effects on the Performances of YAG‐Based WLEDs

The effect of the phosphor curvature in the range 0.1766–0.2589 mm^?1 on the luminous efficacy of Y_2.95Al₅O₁₂:0.05Ce³⁺ (YAG)‐based white‐light‐emitting diodes (WLEDs) was investigated at the similar correlated color temperature (CCT) of ~6300 K by tuning the concentration of YAG phosphors in the phosphor layer ranging from 7.5 to 15 wt%. It was found that both the luminous efficacy and luminous power increased monotonically with the increasing curvature. The luminous efficacy (=82.4 lm/W) and luminous power (=297.85 mW) of the YAG‐based WLED at the preferable phosphor curvature of 0.2589 mm^?1 were 19.44% and 17.36%, respectively, higher than those at the curvature of 0.1766 mm^?1 under 350 mA. This finding reveals that the surface curvature of phosphor layers is a critical factor which cannot be ignored for the investigation of the light output of phosphor‐converted WLEDs. Moreover, the color rendering index (CRI) enhancement of YAG‐based WLED with substitution of Y_2.94Al₅O₁₂:0.05Ce³⁺, 0.01Pr³⁺ (YPrAG), Y_2.45Gd_0.5Al₅O₁₂:0.05Ce³⁺ (YGdAG), and Y_2.95Al_4.8Si_0.2O_11.8N_0.2:0.05Ce³⁺ (YAlSiON) for YAG were assessed under the same phosphor curvature of 0.2589 mm^?1 and the similar CCT ~6350 K. Taking the luminous efficacy, preparation cost of phosphors, and CRI into consideration, we suggest that the YGdAG is a preferable candidate for replacing the YAG for use in WLEDs among the four kinds of phosphors. Compared with the YAG (7.5 wt%)‐based WLED, the YGdAG (7 wt%)‐based WLED exhibited an improved CRI, less preparation cost of phosphors, and the acceptable reduction in luminous efficacy under 350 mA.     

Coaxial structured Bi2S3–SnS2-MWCNT hybrid nanocomposite with its improved thermoelectric properties

Bismuth(III) sulfide (Bi₂S₃), tin(IV) sulfide (SnS₂), and a multi-walled carbon nanotube (MWCNT) are prepared as a hybrid composites (Bi₂S₃–SnS₂-MWCNT) using a simple hydrothermal method. The as-prepared hybrid composite exhibit n-type thermoelectric (TE) characteristics and an enhanced power factor (PF) value. Bi₂S₃–SnS₂ composites are anchored to the surface of MWCNT and form a coaxial structure. The nanostructure formation through bonding between these different materials is confirmed via scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS). The TE properties of the Bi₂S₃–SnS₂-MWCNT composite is improved by changing the Bi₂S₃, SnS₂ and MWCNT content. The maximum PF (∼150.8 μ·W/m·K²) was obtained for Bi₂S₃–SnS₂-MWCNT composite with Bi:Sn ratio of 7:3 and 2 wt% of CNT. The highest PF values were ∼34 and ∼58 times higher than the PF of Bi₂S₃ and SnS₂ at room temperature. The synthesized Bi₂S₃–SnS₂-MWCNT hybrid nanocomposite can provide important components for fabrication CNT-based TE composites with high conversion efficiency, further advancing TE device.     

D-A copolymers based on 5,6-difluorobenzotriazole and oligothiophenes: Synthesis,field effect transistors,and polymer solar cells

Two new 5,6-difluorobenzotriazole (FBTA)-oligothiophene copolymers PFBTA-3T and PFBTA-4T, comprising terthiophene (3T) and quaterthiophene (4T) on the backbone, respectively, were successfully synthesized. A new route to synthesize FBTA monomer was established. Polymers PFBTA-3T and PFBTA-4T exhibited good solubility in common organic solvents and good thermal stability. In comparison to poly (3-hexylthiophene), the incorporations of the FBTA as in PFBTA-3T and PFBTA-4T could result in smaller band gaps around 1.83 eV for the two copolymers. The HOMO levels of PFBTA-3T and PFBTA-4T were −5.49 and −5.31 eV, respectively, while their LUMO levels were −3.65 and −3.90 eV, respectively. In field-effect transistors fabricated without high temperature thermal annealing, PFBTA-3T and PFBTA-4T could display hole mobilities of 1.68 × 10⁻³ and 1.31 × 10⁻² cm² V⁻¹ s⁻¹, respectively. The mobility for PFBTA-4T is the highest among the reported FBTA-based polymers, suggesting that FBTA is a promising heterocycle to construct polymers with high mobility. Polymer solar cells were also fabricated with PFBTA-3T and PFBTA-4T as the donor and PC₆₁BM as the acceptor. With copolymer: PC₆₁BM = 1:1.5 as the active layers, polymer solar cells showed power conversion efficiencies of 3.0% and 2.51% for PFBTA-3T and PFBTA-4T, respectively.     

Preparation and evaluation of nanocomposites of polyfuran with Al2O3 and montmorillonite clay

High yield oxidative polymerization of furan was accomplished in CHCl₃ solvent at 0 °C. A nanocomposite of polyfuran (PF)–Al₂O₃ was prepared through polymerization of furan in a suspension of nanodimensional Al₂O₃ in CHCl₃ at 0 °C. High yield polymerization of furan was also achieved in montmorillonite clay (MMT) without any extraneous oxidant. The formation of PF was confirmed by FTIR and elemental analysis. Thermogravimetric analyses revealed the following trends in thermal stability: PF < PF–Al₂O₃ < Al₂O₃ and PF < PF–MMT < MMT. Scanning electron microscopy showed the average particles sizes to be ca 51 nm and ca 40 nm for PF–Al₂O₃ and PF–MMT composites, respectively. The occurrence of a peak at 19.84 Å in the X‐ray diffraction pattern of the PF–MMT composite was indicative of the intercalation of PF in MMT lamellae. Transmission electron microscopic analyses for the PF–MMT composite also showed incorporation of PF moieties in‐between the MMT layers. The dc conductivity values (S cm^?1) of PF–FeCl₃, PF–Al₂O₃–FeCl₃, PF–MMT and PF–MMT–FeCl₃ systems were in the order of 10^?6, 10^?7, 10^?8 and 10^?7, respectively, and the values were significantly enhanced compared to the dc conductivity value of PF homopolymers (10^?11). Copyright © 2004 Society of Chemical Industry     

Electroluminescence performance of a series of fluorene/2,5-di(2-thienyl)-1H-pyrrole polymers

In this article, a series of fluorene/2,5-dithenyl-1H-pyrrole-based electroactive polymers (HS-X) with different feed ratio of SC12F/OF were synthesized via Suzuki coupling reactions. Chemical characterization of polymers was elucidated by ¹H NMR and Fourier-transform infrared spectroscopy. Electrochemical and electrophysical characterization of the synthesized polymers were investigated by cyclic voltammetry, UV-vis spectroscopy, and fluorescence spectroscopy. Thermal stability of polymers were studied with differential scanning calorimetry and manipulation of the Tg values of HS-X polymers was managed by increasing the numbers of the spiroalkylated fluorene (SAF) moieties incorporated into the polymer backbone. Five different conjugated polymers (HS-1, HS-2, HS-3, HS-4, and HS-5) were used as hole transport layer material in the fabrication of organic light-emitting diode (OLED) devices. The energy levels of the highest occupied molecular orbital as well as the lowest unoccupied molecular orbital and photoluminescence intensities were independent of the number of SAF units. OLED devices based on HS-X polymers were fabricated according to ITO/PEDOT:PSS/HS-X/Alq3/LiF:Al device configuration. Their electroluminescence performances were investigated and the best performance were obtained with the polymer containing 20% SC12F (HS-4) in an OLED device with a turn on voltage of 11.8 V, a maximum luminance of 1202 cd/m² and a maximum luminous efficiency of 0.30 cd/A compared to other polymers with different feed ratio.     

New tetraphenylethylene-containing conjugated polymers: Facile synthesis,aggregation-induced emission enhanced characteristics and application as explosive chemsensors and PLEDs

In this paper, tetraphenylethylene (TPE) units, one of the typical aggregation-induced emission (AIE) moieties, are utilized to construct a new functional polyfluorene (PF) P1, which exhibited the exciting property of the aggregation-induced emission enhancement (AIEE), instead of the aggregation-caused quenching (ACQ) of normal PFs, and could probe the explosive with high sensitivity both in the nanoparticles and solid state. Three other TPE-containing polymers, P2–P4, were also successfully prepared, and demonstrated good performance as explosive chemosensors and light-emitting materials. P3, bearing carbazole as hole-transporting units showed the best performance with a maximum luminance efficiency of 1.17 cd/A and a maximum brightness of 3609 cd/m² at 12.9 V in its light-emitting diode device.     

Synthesis and photovoltaic properties of alternative copolymers of benzo[1,2-b:4,5-b′]dithiophene and thiophene

Two conjugated polymers containing benzodithiophene (BDT) unit and the unit of thiophene or thieno[3,2-b]thiophene, P(BDT-T) and P(BDT-TT), were synthesized by Pd-catalyzed Stille coupling method. The UV–Vis absorption, thermal, and electrochemical properties of the two polymers were characterized. Photovoltaic properties of the polymers were studied by using the polymers as donor and PC₇₀BM as acceptor with a weight ratio of polymer: PC₇₀BM of 1:1.5. The power conversion efficiencies of the PSC devices based on P(BDT-T) reached 2.05% with an open-circuit voltage of 0.75 V, a short-circuit current of 4.5 mA cm⁻², and a fill factor of 0.61, under the illumination of AM1.5, 100 mW cm⁻².     

Preparation and chemical properties of π-conjugated poly(1,10-phenanthroline-3,8-diyl)s with crown ether subunits

π-Conjugated polymers consisting of 1,10-phenanthroline units and crown ether subunits (Poly-1, Poly-2, and Poly-3) were prepared by dehalogenation polycondensation of the corresponding dibromo monomers using a zero-valent nickel complex as a condensing agent. They were characterized by elemental analysis, ¹H NMR and UV–Vis spectroscopies, and cyclic voltammetry (CV). They were partly soluble in CHCl₃, and the number average molecular weight of the soluble part of Poly-2, which had 15-crown-5 subunits, was estimated to be 5300. The polymers exhibited UV–Vis peaks at approximately λ_max = 360 nm, which was reasonable. Complexation with [Ru(bpy)₂]²⁺ and alkaline metal ions made the polymer soluble in organic solvents. The complexation of [Ru(bpy)₂]²⁺ to the 1,10-phenanthroline unit proceeded quantitatively, and the [Ru(bpy)₂]²⁺ complexes exhibited CV curves characteristic of [Ru(N-N)₃]²⁺ complexes.