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White circularly polarized organic light‐emitting diodes (CP‐WOLEDs) are central to prospective 3D displays and lighting sources. However, owing to the unwanted charge trapping effect and inefficient chirality transfer, the development of CP‐WOLEDs with a high color rendering index (CRI) and large dissymmetry factor (gEL) is challenging. Herein, a pioneering strategy of chiral co‐assembly‐sensitized circularly polarized luminescence (CCS‐CPL) is proposed for improving the performance of white circularly polarized electroluminescence (CP‐EL). Chiral co‐assembled sensitizers ((S‐/R‐Cz)0.2‐(I‐P)0.8) are smartly developed using π–π stacking interactions between the chiral binaphthyl derivatives (S‐/R‐Cz) and achiral conjugated pyrene‐based polymer (I‐P) in a molar ratio of 1:4. Using the chiral co‐assembly‐sensitized strategy on achiral aggregation‐induced emission (AIE) dyes for emitting layers (EMLs) of OLEDs, full‐color achiral AIE‐active dyes can be sensitized by chiral co‐assembly (S‐/R‐Cz)0.2‐(I‐P)0.8. The color‐tunable white CP‐EL performance can be achieved at the CIE coordinates of (0.33, 0.33) with an ultrahigh CRI of 93 and a large gEL value up to 0.071. This study thus provides a valuable guidance for CCS‐type CP‐WOLEDs. [ABSTRACT FROM AUTHOR]

This paper delves to improve the upper‐limit temperature of hydrogenated nitrile rubber (HNBR) through regulation of the vulcanization process, filler system and cross‐linking additive. The tensile test and scanning electron microscope images showed that the aging at 180°C significantly accelerated the deterioration in the property of HNBR compared with 150°C aging. The results showed that a higher dosage of bis(1‐(tert‐butylperoxy)‐1‐methylethyl)‐benzene curing agent reduced the compression set of HNBR without sacrificing its tensile strength. Carbon black N539‐filled HNBR exhibited high tensile strength, while carbon black N774‐filled HNBR showed high heat resistance and low compression set. When the HNBR sample was reinforced with 20 phr of N539 and 20 phr of N774 carbon black, it achieved low compression set, high tensile strength, and heat resistance simultaneously. Then, N,N′‐bismaleimide‐4,4′‐diphenylmethane (BMI) was introduced into the HNBR composite as a cross‐linking assistant agent. The residual strength of BMI‐modified HNBR was 20.3 MPa (the retention rate of 92.3%), and its compression set was as low as 19.2% after aging at 180°C for 72 h. Even after aging the composite at 180°C for 168 h, its strength retention rate remained at 83.2% (18.3 MPa). The approach provided here increased the upper‐limit temperature range of HNBR to 180°C. [ABSTRACT FROM AUTHOR]

It is noteworthy that cholesteric liquid crystal (CLC) platforms have been witnessed in high‐performance circularly polarized luminescence (CPL) behaviors through the highly organized chiral co‐assembled arrangement of achiral dyes. However, most CPL‐active design strategies are closely relative to the helix co‐assembly structure of CLC rather than achiral dyes. Herein, we developed an intriguing regulation strategy for CPL‐active CLC materials. They were regulated using the orientational order parameter (SF) of achiral dichroic dyes as an incisive probe for the order arrangement degree of achiral dyes in CLC media. The I‐shaped phenothiazine derivative PHECN dye (SF=0.30) emitted a strong CPL signal (|glum|=0.47). In contrast, the T‐shaped derivative (PHEBen) dye (SF=0.09) showed a weak circular polarization level (|glum|=0.07) at similar CLC textures. Most interestingly, this kind of dichroic PHECN dye with a higher SF could greatly improve the contrast ratio of CPL (Δglum=0.47) and emission intensity (ΔFL=46.0 %) at direct‐current electric field compared with the T‐shaped PHEBen (Δglum=0.07 and ΔFL=1.0 %) in CLC. This work demonstrates that an induced CPL emission can be mediated using achiral dichroic dye, which will open a new avenue for developing excellent CPL‐active display materials. [ABSTRACT FROM AUTHOR]

Circularly polarized organic light‐emitting diodes are of great significance in 3D displays. However, achieving circularly polarized electroluminescence (CP‐EL) simultaneously with a large dissymmetry factor (gEL) and high efficiency still remains a formidable challenge. Herein, a facile and efficient strategy is developed for improving the performance of CP‐EL devices using device emitting layers of chiral coassembled helix nanofiber host materials. Chiral coassembled helix nanofiber host materials ((S‐/R‐2Cz)0.2‐(PFpy)0.8) could be smartly constructed through intermolecular π–π stacking interactions between the achiral conjugated pyridine‐based polymer acceptor (PFpy) and the chiral binaphthyl‐based donor (S‐/R‐2Cz). Significantly, the resulting chiral coassembled hosts (S‐/R‐2Cz)0.2‐(PFpy)0.8 greatly promote a commercially available achiral phosphorescence emitter to achieve solution‐processed red CP‐EL device performances at 620 nm with a high external quantum efficiency of 4.1% and a large |gEL| value of 0.014. [ABSTRACT FROM AUTHOR]

The properties of modified polypropylene (PP) materials are closely related to their phase structure. In this work, polyolefin elastomer (POE)‐toughened PP materials with different phase structures were designed by using various types of POEs (ethylene‐butene 710, 110, ethylene‐propylene 6202, ethylene‐octene 8200). Then, the effects of phase separation in PP/POE blends on both thermal and tensile properties as well as ultraviolet (UV) resistance were investigated. The results revealed that the POE type hardly affected the melt flow rate, melting or crystallization behavior of the modified PP samples. Moreover, scanning electron microscopy results showed that POE6202 had a smaller dispersed phase size in PP (0.1–0.5 μm), which improved the low‐temperature elongation at break. PP/POE110 blends with a larger microdomain (1–5 μm) had better high‐temperature tensile strength. Further, when toughened with POE110 and POE6202 simultaneously, modified PP had excellent low‐temperature elongation (272%@ −40°C) without sacrificing as much of its high‐temperature tensile strength (10.4 MPa@70°C). Finally, Electron Paramagnetic Resonance tests showed that the addition of amorphous POE decreased the intensity of free radicals generated in PP during irradiation and promoted their attenuation during decay. This indicated that the introduction of POE improved the UV resistance of PP. [ABSTRACT FROM AUTHOR]

White circularly polarized organic light‐emitting diodes (CP‐WOLEDs) are of great significance in potential lighting sources and full‐color 3D displays. However, High‐performance white CP‐EL sources are almost unexplored. We have constructed full‐color CP‐EL devices based on chiral co‐assemblies by using three achiral conjugated pyrene‐based dyes (BP, w‐WP and c‐WP) doped with chiral binaphthyl‐based enantiomers (S‐/R‐M) as the EMLs through an intermolecular chirality induction mechanism. (S‐/R‐M)0.2‐(c‐WP)0.8 films exhibit regular helix nanofibers under annealing treatment and emit strong white CPL. Significantly, remarkable CP‐WOLEDs based on (S‐/R‐M)0.2‐(c‐WP)0.8 were achieved with |gEL| values as high as 6.2×10−2 and an excellent CRI of 98 at the CIE coordinates of (0.33, 0.33). These are the highest gEL and CRI values of reported CP‐WOLEDs to date. This is the first achievement of CP‐WOLEDs based on chiral co‐assembled helix nanofiber emitters, and provides a valuable strategy with which to develop white CP‐EL for future practical applications. [ABSTRACT FROM AUTHOR]

In this work, a chiral functionalized bis‐benzoxanethonyl unit is introduced into three conjugated polymer backbones (S‐/R‐BP, S‐/R‐WP1, and S‐/R‐WP2) as the emitting layers (EMLs) of organic light‐emitting diodes (OLEDs) to construct full‐color circularly polarized electroluminescence (CP‐EL) by solution‐processing. Interestingly, standard white CP‐EL based on the monodispersed S‐/R‐WP2 achieves a high color rendering index of 95 at CIE coordinates of (0.33, 0.34). The CP‐OLED performances show the turn‐on voltage of ≈5.8 V, high maximum luminance of ≈3000 cd m−2, and stable gEL value of 10−3 in the wavelength range of 425–760 nm. This work is the first example to realize standard white CP‐OLEDs by intramolecular chirality transfer mechanism from chiral blue‐color moiety to achiral red‐color dye through polymer chain, which provides a valuable strategy to develop white CP‐EL for potential lighting and full‐color 3D displays. [ABSTRACT FROM AUTHOR]

Two chiral binaphthyl polymers (R/S‐P1 and R/S‐P2) with different dihedral angles of the binaphthyl moiety were chosen as chiral inducers to construct chiral co‐assemblies with an achiral pyrene‐naphthalimide dye (NPy) and then acted as the emitting layer (EML) of circularly polarized electroluminescence (CP‐EL) devices. The anchored dihedral angle of R/S‐P2 not only exhibited the enhanced chirality signal, but also had a strong chirality‐inducing effect on the achiral NPy dye in the chiral co‐assembly (R/S‐P2)0.6‐(NPy)0.4. After annealing at 120 °C, the CPL signal (|gem|) of ordered helical nano‐fibers (R/S‐P2)0.6‐(NPy)0.4 was amplified to 5.6×10−2, which was about 6‐fold larger than that of (R/S‐P1)0.6‐(NPy)0.4. The amplified gem value of (R/S‐P2)0.6‐(NPy)0.4 was due to the formation of a helical co‐assembly through the strong π–π stacking interaction between the R/S‐P2 and the achiral NPy. This kind of ordered helical nano‐fibers (R/S‐P2)0.6‐(NPy)0.4 acted as the EML of CP‐OLEDs, and achieved an excellent CP‐EL performance (|gEL|=4.8×10−2). [ABSTRACT FROM AUTHOR]

The application of polypropylene (PP) is greatly restricted by its poor low‐temperature tensile properties. In this work, a polypropylene random copolymer (rPP) and polypropylene/ethylene‐propylene‐diene monomer graft copolymer (gPP) were used to improve the toughening effect of polyolefin elastomer (POE) on PP. The influences of this addition on the phase morphology, crystallization, and rheological and mechanical properties were investigated. The results revealed that rPP both reduced the size of PP spherulites and improved the interfacial cohesion of the PP/POE blend, which endowed the material with greater tensile properties and melt flow rate. The elongation at break of PP/POE/rPP at 23, 0, −20, and −40°C was 400%, 221%, 205%, and 106%, respectively. These represented increases of more than 200% compared with those of PP/POE. The tensile strengths of PP/POE/rPP were 15.0, 19.1, 21.5, and 27.4 MPa at 23, 0, −20, and −40°C, respectively, which were comparable to those of PP/POE. Finally, the effects of the injection molding process parameters on the mechanical properties and phase morphology of rPP‐modified PP/POE blends were studied. [ABSTRACT FROM AUTHOR]

Chiral emissive nematic liquid crystals (N*‐LCs) can greatly amplify the circularly polarized luminescence (CPL) signals promoted by a highly regular spiral self‐assembly in the LCs system. Naphthalimide (NI) derivatives have been assigned to be one of the most excellent chromophores for fluorescent materials. In this paper, a novel strategy is first developed to regulate full‐color CPL behavior of N*‐LCs through different chiral NI‐based dyes. Chiral NI‐based dyes are doped into nematic liquid crystals (E7, N‐LCs) to form N*‐LCs as CPL‐active liquid crystal materials. Most interestingly, this kind of N*‐LCs could emit standard white CPL signals (CIE coordinates: (0.31, 0.33)) by choosing the blue‐red match of two chiral NI‐based dyes at the appropriate ratio. [ABSTRACT FROM AUTHOR]

The development of excellent circularly polarized luminescence (CPL) materials with both a high luminescence dissymmetry factor (glum) and high quantum yield (Φlum) is crucial for realizing 3D displays. Herein, we prepared chiral-emitting ternary liquid crystals (T-N*-LCs) containing the chiral binaphthyl dopant R/S-BF (a chiral inducer and energy donor) and the achiral dye Nile Red (a CPL emitter and energy acceptor) using the commercial nematic liquid crystals E7 (N-LCs) as a host. These ternary N*-LCs exhibited a photosensitive-type red CPL response controlled by an intermolecular dynamic Förster resonance energy transfer (FRET) mechanism. Under irradiation with 365 nm ultraviolet light (hand-held 1.0 mW cm−2 UV light), the binary-emitting liquid crystals containing R/S-BF in E7 showed a transition from a strong green CPL signal (λem = 480 nm, glum = +0.28/−0.25) to weak blue CPL (λem = 438 nm, glum = +0.03/−0.028) due to the Z-to-E isomerization of R/S-BF. Interestingly, T-N*-LCs loaded with the energy receptor Nile Red exhibited interconversion between a "strong" and "weak" red CPL response before and after irradiation with 365 nm UV light, which can be attributed to an intermolecular dynamic FRET process based on different overlap between the absorption of the acceptor (NR) and the distinct emissions of the Z- and E-isomers of the donor R/S-BF. Strong red CPL emission (glum = +0.63/−0.65, λem = 625 nm) was observed due to the high helical twisting power of Z-R/S-BF and efficient FRET from Z-R/S-BF to NR. This work paves the way for the construction of chiral optical information storage with photochromic change functionality. [ABSTRACT FROM AUTHOR]

Recently, much attention has been paid to circularly polarized luminescence (CPL) organic light-emitting diodes (CP-OLEDs) from achiral fluorophores through an intermolecular chirality induction mechanism. In this paper, we developed a new strategy for CP-OLEDs of achiral fluorophores induced by helical co-assembly between chiral polymers and an achiral fluorophore. In this paper, we synthesized three chiral 1,1′-binaphthyl-based polymers (R/S-P1 , R/S-P2 and R/S-P3) with different side chain alkyl groups (n-C4H9; n-C6H13; n-C8H17), which can act as chirality inducers and form chiral co-assemblies with an achiral pyrenyl fluorophore (Bpy). At a 50% doping weight ratio of R/S-P2 inducer with Bpy, this kind of chiral co-assembly (R/S-P2-Bpy) can exhibit helical nano fibers and emit a strong deep blue CPL signal (λem = 420 nm, dissymmetry factor ‖gem‖ = 0.042) in spin-coated films after annealing (120 °C). Moreover, the stable CP-OLEDs using R/S-P2-Bpy as the device emitting layer (EML) can emit strong CP-EL with an electroluminescence dissymmetry factor ‖gEL‖ of up to 0.021. [ABSTRACT FROM AUTHOR]

With the rapid development on 3D printing technology, more and more works have been devoted to 3D display. 3D display will really come true by using circularly polarized luminescence (CPL)‐active materials with both high quantum yield and dissymmetry factor (gem) in organic light‐emitting diode or liquid crystals (LCs). But so far most of these CPL materials cannot meet the real application requirement because of the low gem values in the range of 10−5–10−2. In this paper, ternary chiral emissive LCs (P‐N*‐LCs) is designed by doping chiral binaphthyl‐based enantiomers as chiral dopant (Guest 1) and achiral conjugated polymer as induced CPL emitter (Guest 2) into nematic liquid crystal (N‐LCs) Host 5CB. Both Guest 1 and Guest 2 show excellent compatibility with Host 5CB. The obtained ternary P‐N*‐LCs can emit strong‐induced CPL signal with gem up to 1.12 and ФFL up to 66.1%. This work first develops a new strategy for the smart design of excellent CPL materials from versatile achiral conjugation fluorescence polymers. [ABSTRACT FROM AUTHOR]

By combining the blue and orange CPL or functionalized bis‐benzoxanethones emitters (S‐/R‐BN‐tCz and S‐/R‐BN‐PXZ), warm white CP‐OLEDs were fabricated using solution‐processed single emitting layer strategy. The successful realization of white CP‐EL benefited from the same stable binaphthyl chirality and similar rigid structure of the two emissive CPL emitters. The devices exhibited the low turn‐on voltage of ≈4.3 V, maximum luminance of ≈10200 cd m−2 and maximum current efficiency of ≈2.0 cd A−1. Most significantly, the devices with CIE coordinates of (0.32, 0.45) displayed intense CP‐EL signals in the spectral range of 450 to 650 nm, and showed stable gEL values of ≈10−3 as the luminance increased from 100 to 6000 cd m−2. To the best of our knowledge, this work provides for the first time a simple and feasible strategy to fabricate solution‐processed white CP‐OLEDs based on the co‐doping of the CPL emitters. [ABSTRACT FROM AUTHOR]

Chiral organic polymers have considerable potential in solution-processable circularly polarized organic light emitting diodes (CP-OLEDs) due to their simple, low cost and large-area processing. Achiral conjugated poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]-thiadiazol-4,8-diyl)] (F8BT) is a donor–acceptor copolymer with superior characteristics including its ability to uniformly disperse chiral dopants and form homogeneous and smooth films. This paper describes the design and development of blue-emission chiral enantiomers R-/S-3 bearing pyrene groups as fluorophores and 2,2′-methylenedioxy-1,1′-binaphthalene moieties as chiral sources. Enantiomers R-/S-3 exhibit high thermal properties, outstanding photoluminescence properties and sufficient solubility in common organic reagents. The CP-OLEDs using R-/S-3 as the blue emission emitting layer show excellent efficiency, high brightness, and low turn-on voltage in non-doped OLEDs. Moreover, we further employed achiral conjugated fluorescent polymer F8BT, blended with blue-emitting chiral dopants (R-/S-3), as the device emitting layer. The CP-OLEDs based on blends of F8BT + 10% R-/S-3 showed low turn-on voltage (Von = 4.1 V), excellent current efficiencies (4.19 cd A−1 for F8BT + 10% R-3 and 4.06 cd A−1 for F8BT + 10% S-3), and high brightness (21797.8 cd m−2 for F8BT + 10% R-3 and 20572.6 cd m−2 for F8BT + 10% S-3). To our knowledge, this is, to date, the best device performance using blends of achiral fluorescent polymers and chiral inducers in solution-processable CP-PLEDs. The outcomes obtained in this study can provide us with a valuable reference for future studies on the induced CPL-active device design. [ABSTRACT FROM AUTHOR]

Ternary polymer dispersed cholesteric liquid crystals (PD-CLCs) prepared by doping AIE-active binaphthyl-based molecules (R/S-AD, chiral dopant) and the achiral liquid crystal fluorescent polymer, poly(p-phenylene ethynylene) (LC-PPE, CPL emitter) into 5CB, can emit strong circularly polarized luminescence (CPL) with gem up to 0.97. This work develops a new strategy for designing strong CPL materials. [ABSTRACT FROM AUTHOR]

This article explores the possibility of using polyolefin materials for composite insulator sheds. The transfer component (silicone oil or erucamide) is added into a polyolefin material to improve its hydrophobic properties. Results show that the silicone oil‐modified polyolefin material (polyolefin‐S) exhibited an obvious hydrophobicity transfer property. When the equivalent salt deposit density and nonsoluble deposit density are 0.1 and 0.5 mg/cm2, respectively, the static contact angle increases from 75° to 87° as the silicone oil transfer time increases from 24 to 96 hr. Meanwhile, polyolefin‐S exhibits high mechanical strength, hardness, volume resistivity, and surface resistivity values of 21.4 MPa, 62.6 HD, 1.7 × 1015 Ω m and 1.2 × 1016 Ω, respectively. Moreover, polyolefin‐S shows excellent tracking and erosion resistance of 4.5 kV level in the inclined plane test. The results verify that the polyolefin material is a promising candidate material for the hard shed of composite insulators. [ABSTRACT FROM AUTHOR]

Two pairs of D–A type AIE-active chiral dyes (R-/S-1 and R-/S-2) as chiral emitters doped into nematic liquid crystals (5CB, N-LCs) can form chiral nematic liquid crystals (N*-LCs) and regulate the amplified circularly polarized luminescence (CPL) signals. R-/S-2 with stronger D–A structure and more planar conformation could induce higher CPL response (glum = ±0.37) via the supramolecular self-assembly in N*-LCs system. [ABSTRACT FROM AUTHOR]

Three-component conjugated polymers of a strong donor–acceptor (D–A) type could be synthesized by Pd-catalyzed Suzuki coupling polymerization reaction of 1,2-bis(4-bromophenyl)-1,2-diphenylethene (M-1) with 9-octyl-3,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole (M-2) and 4,6-bis((E)-4-bromostyryl)-2,2-difluoro-5-phenyl-2H-1l3,3,2l4-dioxaborinine (M-3). Among them, P-1 and P-2 with high TPE ratios at 0.95 and 0.9 showed obvious aggregation-induced emission (AIE) behavior; in contrast P-3 with a low TPE ratio at 0.8 showed an aggregation-caused quenching (ACQ) phenomenon. In particular, the three resulting polymer dots (P-1 to P-3 Pdots) exhibited a 200 mV lower electrochemiluminescence (ECL) potential due to their strong D–A electronic structure. Most importantly, the ECL signals of Pdots could be enhanced as high as 3 times by increasing their AIE-active TPE moiety ratios from 0.8 (P-3) to 0.95 (P-1) via the band gap emission process. Herein, P-1 Pdots with the strongest ECL signal were successfully used as ECL biosensors for the detection of catechol, epinephrine and dopamine with detection limits of 1, 7 and 3 nM, respectively. This work provides a new strategy for developing highly sensitive ECL biosensors by the smart structure design of the AIE-active Pdots. [ABSTRACT FROM AUTHOR]

Two pairs of CPL-active binaphthyl-pyrene emitters with good photophysical properties and excellent chiroptical performances can emit high brightness blue CP-EL. The theoretical calculation results show that R-/S-5 can form rigid helix π–π stacking in the aggregation state which may greatly contribute to gEL of CP-OLEDs. [ABSTRACT FROM AUTHOR]

The dynamic chemistry of disulfide bonds has emerged as one of the most powerful tools used for the fabrication of organic compounds and self‐healing materials. In this article, a novel aromatic amine‐terminated polysulfide oligomer is first synthesized from thiol‐terminated polysulfide oligomer and bis(4‐aminophenyl) disulfide via disulfide metathesis mechanism. The resulting oligomer is confirmed by FTIR and 1H NMR spectra and then successfully applied in constructing self‐healable polyurea material (A‐LP23‐I), which combines the advantages of higher strength of polyureas and excellent self‐healing ability of polysulfide‐based materials. After subjecting to a temperature of 75 °C for 48 h, both the tensile strength and ultimate elongation of A‐LP23‐I restore to more than 90% of the original values (3.32 MPa and 396%). This study demonstrates a novel strategy for synthesizing aromatic amine‐terminated oligomer. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1460–1466 [ABSTRACT FROM AUTHOR]