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Light-Triggered Reversible Self-Engulfing of Janus Nanoparticles
摘要： Block copolymers containing azobenzene liquid crystalline (LC) mesogen are used to prepare snowman-like Janus nanoparticles (NPs) by emulsion solvent evaporation. The azobenzene-containing poly(methacrylate) (PMAAz) head of the Janus NPs is in the smectic LC phase with ordered stripes, which becomes amorphous and enlarged due to trans/cis transformation under UV irradiation. The expanded PMAAz can consequently engulf the other head. The self-engulfed NPs can recover to their original state in both shape and LC state via visible-light irradiation. This strategy is promising for programmable load and release of different payloads by remote trigger using light.
关键词： emulsion solvent evaporation,azobenzene,liquid crystalline,Block copolymers,Janus nanoparticles,programmable load and release,UV irradiation,visible-light irradiation
更新于2025-09-23 15:21:01
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Conjugated Polymers Containing BODIPY and Fluorene Units for Sensitive Detection of CN? Ions: Site-Selective Synthesis, Photo-Physical and Electrochemical Properties
摘要： Conjugated polymers containing distinct molecular units are expected to be very interesting because of their unique properties endowed by these units and the formed conjugated polymers. Herein, four new conjugated copolymers based on fluorene and 4,4’-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) have been designed and synthesized via Sonogashira polymerization. The fluorene unit was attached to the 3,5- or 2,6-positions of BODIPY by ethynylenes or p-diacetylenebenzene. The obtained polymers show good thermal stability and broad absorption in the wavelength range from 300 to 750 nm. The effects of site-selective copolymerization and conjugation length along the polymer backbone on the optoelectronic and electrochemical properties of these copolymers were systematically studied by UV-Vis spectroscopy, photoluminescence (PL) and cyclic voltammetry. Besides, it is found that the BODIPY-based copolymers exhibit selectively sensitive responses to cyanide anions, resulting in obvious change of UV-Vis absorption spectra and significant fluorescence quenching of the polymers among various common anions.
关键词： conjugated copolymers,site-selective,cyanide anion,BODIPY
更新于2025-09-23 15:21:01
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Photo-controlled RAFT polymerization mediated by organic/inorganic hybrid photoredox catalysts: enhanced catalytic efficiency
摘要： Photo-controlled RAFT polymerization mediated by organic/inorganic hybrid photoredox catalysts: enhanced catalytic efficiency. Metalloporphyrins (MTPPs) play an important role in the conversion of light energy to initiate photo-induced electron transfer–reversible addition–fragmentation chain transfer (PET-RAFT) polymerization, in which zinc tetraphenylporphyrin (ZnTPP) has attracted a high degree of attention. However, the self-aggregation effect of porphyrins in some organic solvents such as dimethyl sulphoxide (DMSO) leads to quenching of the excited state of the MTPPs and reduces their photocatalytic capacity in a concentration-dependent manner. In this study, a ZnTPP–POSS organic/inorganic complex was fabricated by linking a polyhedral oligomeric silsesquioxane (POSS) to ZnTPP. The aggregation of the photocatalyst was efficiently depressed in a PET-RAFT polymerization which was catalyzed by ZnTPP–POSS under green light (λmax = 515 nm, 3 mW cm?2). Compared to ZnTPP, the reactions using ZnTPP–POSS as the photocatalyst were well controlled for different monomers with accelerated reaction rates. Well-defined block copolymers were successfully achieved by the chain-extension reaction which demonstrates the high-end fidelities of this polymerization approach.
关键词： Photo-controlled RAFT polymerization,PET-RAFT polymerization,organic/inorganic hybrid photoredox catalysts,block copolymers,ZnTPP–POSS
更新于2025-09-23 15:19:57
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Development of Block Copolymers with Poly(3-hexylthiophene) Segments as Compatibilizers in Non-Fullerene Organic Solar Cells
摘要： P3HT-segment-based block copolymers have been reported to deliver an effective compatibilizer function in the P3HT:PC61BM bulk-heterojunction (BHJ) system to simultaneously improve performance and stability. However, as limited by the deficient optophysic properties of the P3HT:PC61BM system, the resultant power conversion efficiency (PCE) of compatibilizer-mediated devices is low despite the optimized chemical structures of the P3HT-segment-based block copolymers. To better shed light on such compatibilizer effect, the compatibilizer function of the P3HT-segment-based block copolymers is herein investigated in the emerging non-fullerene acceptor (NFA)-based BHJ systems. A P3HT analogue, poly[(4,4′-bis(2-butyloctoxycarbonyl-[2,2′-bithiophene]-5,5-diyl)-alt-(2,2′-bithiophene-5,5′-diyl)] (PDCBT), is used as the polymer donor since it shares the same backbone as P3HT to afford good compatibility with the P3HT-segment-based block copolymers and it has been proven to deliver a higher PCE than P3HT in the NFA BHJ systems. The P3HT-segment-based block copolymers (P1-P4) are manifested to offer similar compatibilizer function for the PDCBT-based NFA BHJ systems and the importance of their structural design is also revealed. As a result, addition of P4 delivers the largest enhancement in PCE: from 5.30% to 7.11% for the PDCBT:ITIC blend and from 6.21% to 8.04% for the PDCBT:IT-M blend. Moreover, it can also enhance device’s thermal stability, which can maintain 77% of initial PCE after annealing at 85 oC for 120 h (for the PDCBT:ITIC blend), outperforming the pristine binary device (66% preservation). More importantly, all the compatibilizer-mediated device exhibits an improved Voc. Such reduced potential loss can be attributed to the improved interfacial compatibility between the photoactive components, the most important function of a compatibilizer.
关键词： compatibilizer,poly(3-hexylthiophene) segment,non-fullerene acceptor,organic solar cells,Block copolymers
更新于2025-09-23 15:19:57
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Synthesis, electrochromic characterization and solar cell application of thiophene bearing alternating copolymers with azobenzene and coumarin subunits
摘要： In this study, azobenzene and coumarin functionalized thiophene comprising two copolymers (poly (4-((3000-hexyl-[2,20:50,200:500,2000-tetrathiophene] (cid:2) 30-yl)methoxy) - 2H-chromen-2-one (P1) and poly (1-(4-((4000-hexyl-[2,20: 50, 200: 500, 2000 - tetrathiophene] (cid:2) 30-yl) methoxy) phenyl) (cid:2)2-phenyldiazene) (P2)), were designed and synthesized according to the donor–acceptor (D–A) approach to investigate their electrochemical, optical and photovoltaic behaviors. Among the various copolymerization methods to obtain P1 and P2, Stille copolymerization reaction was preferred. The HOMO and LUMO values were determined via cyclic voltammetry (CV) as (cid:2)5.64 eV and (cid:2)3.76 eV for P1 and (cid:2)5.47 eV and (cid:2)3.83 eV for P2, respectively. The optical band gaps of the polymers for P1 and P2 were calculated as 1.88 eV and 1.64 eV using UV-VIS spectrophotometer. Electrochemical and spectroelectrochemical studies for synthesized copolymers support their usage in organic solar cell applications. The organic solar cells (OSCs) were designed using polymer as an electron donor group and PC60BM as an electron acceptor group. Performances of OSCs based on P1 and P2 were investigated with the device structure of ITO/PEDOT:PSS/ Polymer(P1/P2):PC60BM/LiF/Al. The preliminary solar cell results were reported here and studies are going on in our laboratories to increase the efficiency. The highest power conversion efficiency was obtained as 0.81% for P1 based device with 0.47 V open-circuit voltage (Voc) and 4.92 mA/cm2 current density (Jsc) values. The highest efficiency for P2 comprising device was found to be 0.96% under optimum conditions with 0.60 V and 4.98 mA/cm2, Voc and Jsc values, respectively.
关键词： Azobenzene,solar cell,coumarin,conducting polymers,thiophene bearing copolymers
更新于2025-09-23 15:19:57
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Distinctive Optical Properties of Hierarchically Ordered Nanostructures Selfa??Assembled from Multiblock Copolymer/Nanoparticle Mixtures
摘要： Hybrid materials with hierarchical nanostructures are of great interest for their advanced functions. However, the effect of the formation of hierarchical nanostructures on properties is not well understood. Here, through combining dissipative particle dynamics simulation and the finite-difference time-domain method, the optical properties of hierarchically ordered nanostructures formed by mixtures of A(BC)n multiblock copolymers and nanoparticles (NPs) are investigated. A series of hierarchically ordered nanostructures with multiple small-length-scale hybrid domains are obtained from the self-assembly of A(BC)n/NP. An increase and blueshift in optical absorption are observed when the number of small-length-scale hybrid domains increases. The small-length-scale hybrid domains enhance light scattering, which consequently contributes to the improved optical performance. These findings can yield guidelines for designing hierarchically ordered functional nanocomposites with light-harvesting characteristics.
关键词： nanostructures,self-assembly,multiblock copolymers,nanoparticles,optical properties
更新于2025-09-23 15:19:57
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Controlled Synthesis of PdII and PtII Supramolecular Copolymer with Sequential Multiblock and Amplified Phosphorescence
摘要： Supramolecular copolymers constitute a fundamental new class of functional materials attracting burgeoning interest, but examples that display phosphorescence and long-lived excited states are rare. Herein, we describe the synthesis of sequential phosphorescent multi-block supramolecular copolymers in one and multiple dimensions using pincer PtII and PdII complexes as building blocks by manipulating out-of-equilibrium self-assemblies via the living supramolecular polymerization approach. Doping a small amount of PtII complexes (2 mol %) into the PdII assemblies significantly boosted the emission efficiency and radiative decay rate constant (Fem = 3.7%, kr = 1.8 3 104 s?1 in PdII assemblies; Fem = 76.2%, kr = 58.6 3 104 s?1 in PtII-PdII co-assemblies), which is ascribed to an external heavy-atom spin-orbital coupling effect arising from the doped PtII complex with a delocalized 3[ds*/p*] excited state. The findings on PtII and PdII supramolecular copolymers with controlled sequences and greatly enhanced phosphorescence efficiencies open the door to new photofunctional and responsive luminescent metal-organic supramolecular materials.
关键词： Living supramolecular polymerization,PtII and PdII complexes,Phosphorescence,External heavy-atom effect,Supramolecular copolymers
更新于2025-09-23 15:19:57
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Determining the sequence and backbone structure of a??semi-statisticala?? copolymers as donora??acceptor polymers in organic solar cells
摘要： Organic photovoltaics (OPVs) are attracting significant attention due to the growing demand for economically viable and renewable energy sources. With efficiencies exceeding 16.5%, single junction bulk heterojunction (BHJ) devices are amongst the most promising and are nearing commercialisation. One recent avenue of research has focused on statistical conjugated copolymers. However, a detailed investigation as to why these materials can achieve higher power conversion efficiencies than their regular alternating counterparts is seldom reported. This work describes an investigation into donor–acceptor polymers demonstrating how differing monomer activities can lead to differing microstructures in a simple batch reaction, which in turn demonstrates promising optoelectronic and morphological properties required for organic photovoltaic devices. A one pot condensation polymerisation reaction with three monomers leads to an ABA triblock structure from differing monomer reactivities. This structure in turn leads to visualised phase separation which is possibly linked to an increase in performance. Further to this we report on the reliability of the Stille coupling for the synthesis of conjugated polymers.
关键词： Organic photovoltaics,Donor–acceptor polymers,Bulk heterojunction devices,Statistical conjugated copolymers,Stille coupling
更新于2025-09-23 15:19:57
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Synthesis, characterization, and application of fluorescent electrically conducting copolymer/metal-oxide nanocomposites
摘要： Solution polymerization of aniline in the presence of fluorescent organic dyes was carried out at 0–5°C for 2 h under nitrogen atmosphere with FeCl3 as an initiator. The copolymers were prepared under different experimental conditions. The prepared copolymers were characterized by various analytical tools. The electrical conductivity was measured. From the absorbance and emission intensity values the order of reaction was calculated. Further, its application toward the reduction of nitrophenol was done and the apparent rate constant (Kapp) was calculated. The Fourier Transform Infra Red (FTIR) spectrum confirmed the presence of benzenoid, quinonoid, and azo functionalities.
关键词： characterization,morphology,Copolymers,synthesis,conductivity,reduction
更新于2025-09-19 17:15:36
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Naphthalene Diimide-Based Terpolymers with Controlled Crystalline Properties for Producing High Electron Mobility and Optimal Blend Morphology in All-Polymer Solar Cells
摘要： We report a series of new n-type random copolymers (P(NDI2OD-Se-Th x) where x = 0, 0.5, 0.7, 0.8, 0.9, 1.0) consisting of naphthalene diimide (NDI), selenophene-2,2’-thiophene (Se-Th), and seleno[3,2-b]thiophene (SeTh) to demonstrate their use in producing efficient all-polymer solar cells (all-PSCs) and organic field-effect transistors (OFETs). To investigate the effect of polymer crystallinity on the performance of all-PSCs and OFETs, we tuned the composition of the Se-Th and SeTh moieties in the P(NDI2OD-Se-Th x) polymers, resulting in enhanced crystalline properties with higher Se-Th ratio. Thus, the OFET electron mobility was increased with higher Se-Th ratio, exhibiting the highest value of 1.38×10?1 cm2 V?1 s?1 with P(NDI2OD-Se-Th 1.0). However, the performance of all-PSCs based on PBDB-T:P(NDI2OD-Se-Th x) showed a non-linear trend relative to the Se-Th ratio and the performance was optimized with P(NDI2OD-Se-Th 0.8) exhibiting the highest power coversion efficiency of 8.30%. This is attributed to the stronger crystallization-driven phase separation in all-polymer blends for higher Se-Th ratio. At the optimal crystallinity of P(NDI2OD-Se-Th 0.8) in all-PSCs, the degree of phase separation, domain purity and the electron mobility were optimized, resulting in enhanced charge generation and transport. Our works describe structure-property-performance relationships to design effective n-type polymers in terms of crystalline and electrical properties suitable for both efficient OFETs and all-PSCs.
关键词： organic field-effect transistors,seleno[3,2-b]thiophene,polymer crystallinity,n-type random copolymers,selenophene-2,2’-thiophene,charge generation,all-polymer solar cells,charge transport,naphthalene diimide
更新于2025-09-19 17:13:59