最新刊期
卷 54 ， 期 6 ， 2023
高分子优秀青年学者
- 摘要：The development of transition-metal-catalyzed reactions has remarkably facilitated the synthesis and applications of alkyne polymers of diverse structures and functions. Classical synthetic strategy of alkyne polymers based on acetylenic monomers includes: (1) acetylenic bond activation that leads to polycouplings; (2) carbon-carbon triple bond activation by metal carbynes/carbenes that leads to metathesis polymerizations. Recently, our group introduced a third mode based on copper-mediated propargylic bond activation of propargylic electrophiles, which generates allenyl copper species as key intermediates. The allenyl copper complex is involved in the in situ formation and chain-growth polymerization of [n]cumulene (n=3, 5), which eventually affords a unique alkyne backbone with carbon-carbon triple bonds spaced by two sp3 carbons with exclusive regioselectivity. This article serves to describe recent developments of transition-metal-catalyzed synthesis of alkyne polymers based on polycouplings, metathesis, and propargylic activation, respectively. In particular, the chain-growth methods in each category are emphasized from a mechanistic perspective because of their potential in controlling the molecular weight and distribution, end groups, sequences, topology of the resulting alkyne polymers. This includes the catalyst transfer Sonogashira-type polycoupling, the ring-opening alkyne metathesis polymerization of strained alkynes, metathesis and metallotropy polymerization, and the emerging copper-catalyzed condensation polymerization of propargylic electrophiles developed by our group. The synergy between organometallic chemistry and synthetic polymer chemistry provides important driving force for both fields.关键词：Transition-metal catalysis;Alkyne polymers;Propargylic substitution;Chain-growth;Cumulenes
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发布时间：2023-05-31 - 摘要：Reversible deactivation radical polymerization (RDRP) has become one of the most common methods for the synthesis of well-defined polymers with predetermined molar mass, narrow molar mass distribution, and precise end-group functionality. Depending on the solubility of monomer/polymer in the polymerization system, RDRP can be performed via either homogeneous polymerization or heterogeneous polymerization. Compared with homogeneous RDRP, heterogeneous RDRP exhibits significant advantages, such as low viscosity, high polymerization rate, and nanoconfinement effect. More importantly, heterogeneous RDRP enables efficient preparation of well-defined polymer nanomaterials that find applications in many areas. Currently, almost all heterogeneous RDRPs are conducted via thermal initiation at high temperatures (e.g. 70 ℃), which is not beneficial for the preparation of many functional polymer nanomaterials. Performing heterogeneous RDRP at room temperature seems to be a minor change in the polymerization process, but this can lead to extensive opportunities for controlled synthesis of functional materials, the development of new heterogeneous RDRP methods, and mechanistic insights into heterogeneous RDRP. Many room-temperature initiations have been successfully introduced into heterogeneous RDRP, such as photoinitiation, enzyme initiation, redox initiation, and sonochemically initiation. In this feature article, we will summarize some recent developments of room-temperature heterogeneous RDRP that are difficult to be achieved via traditional heterogeneous RDRP, including the control of polymerization rate using room-temperature initiations, oxygen-tolerant heterogeneous RDRP via either enzymatic deoxygenation or photo-induced deoxygenation, the development of new heterogeneous RDRP methods (e.g. Z-RAFT mediated dispersion polymerization, wavelength-selective photo-induced heterogeneous RDRP), morphological control of polymer nanomaterials, and the synthesis of functional polymer nanomaterials (bio-related polymer nanomaterials, epoxy-functionalized polymer nanomaterials, and thermo-responsive polymer nanomarterials). Finally, current challenges and further opportunities of room-temperature heterogeneous RDRP are discussed.关键词：Reversible deactivation radical polymerization (RDRP);Heterogeneous polymerization;Room-temperature;Polymer nanomaterials
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发布时间：2023-05-31 - 摘要：Organometallics are one kind of potential catalytic system for synthesis of polyester from ring-opening (co)polymerization, because their catalytic performance can be easily modulated by tuning the Lewis acidity of the metal centre and modifying the electronic or steric effects of ligand backbone. In the past decades, the aluminum complexes with salen-type ligand have been widely used in ring-opening polymerization of cyclic ester, ring-opening copolymerization of (thio)anhydride and epoxide, stereo-selective ring-opening polymerization and chemo-selective multicomponent polymerization for farbricating well-defined polyesters. However, the traditional salen-Al complexes generally suffer from low catalytic activity or complete deactiveation at low catalyst concentration or high concentration of chain transfer agent, owing to the concentration effects and the decomposition of the catalyst caused by protic agents. It is desirable to develop catalytic system with high stability and good compatibility with protonic agents, which is important for decreasing catalyst loading, reducing the cost, minimizing the catalyst residual and increasing the molecular weight. Recently, we synthesized a series of bipyridine bisphenolate aluminum (BpyBph-Al) complexes and used these complexes to catalyze the lactide polymerization, melaic anhydride/epoxide copolymerization and thioanhydride/epoxide copolymerization. This feature article summarizes the recent progress on synthesis of polyesters by using (BpyBph-Al) complexes and discussed the their unique advantages in ring-opening (co)polymerization.关键词：Environmental-friendly polymer;Catalyst;Ring-opening polymerization;Ring-opening alternating copolymerization;Organometallics
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发布时间：2023-05-31 - 摘要：Semiconducting polymers, especially π-conjugated donor-acceptor (D-A) copolymers with defect-free alternating structures, are essential materials for plastic electronics and optoelectronics owing to their advantages of variable/tunable chemical structures, tunable bandgaps and optical absorptions, excellent charge transport mobility, mechanical flexibility, and solution processability for printing. However, the drawbacks including batch-to-batch reproducibility, structural defects, and etc. hindered the commercial application for polymers. Herein, we analyzed the causes of structural defects, especially homocoupling defects in terms of their mechanism of generation by illustrating the example of Stille couplings and the side reactions, the characterization methods, including matrix-assisted laser desorption/ionization (MALDI), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC) as well as ultraviolet-visible (UV-Vis) spectra, and the impact of defects on device performance by investigating the pioneering studies of this field within 5 years. Afterwards, three significant types of polymerizations to achieve copolymers with minimized structural defects have been illustrated separately, including Stille polymerization, Suzuki polymerization and direct arylation polymerization (DArP). From the synthetic perspective, the methodologies for the precision synthesis of conjugated polymers are in high demands and will pave the road for the development of organic electronics.关键词：Conjugated polymers;Precision synthesis;Homocoupling defects;Device performance
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发布时间：2023-05-31 - 摘要：In recent years, conjugated polymers have attracted extensive attention from both industry and academia due to their excellent solution processability and good mechanical properties. The incorporation of quinoidal unit, featured with good π-electron delocalization, rigidity structure and low-lying LUMO energy level, into conjugated backbone is a promising approach to developing high-performance conjugated polymers. However, how to introduce such structure into polymer backbone remains a challenge. In this feature article, we summarized the recent progress of conjugated polymers containing quinoidal structure. According to the structures of quinoidal units, we discussed the design and synthesis of quinoidal monomers. Particularly, we synthesized a series of oxindole- and indandione-terminated quinoidal compounds. The terminal aromatic rings in these quinoidal compounds provide an opportunity to feasibly adjust the properties of conjugated polymers. Furthermore, compared with the reported quinoids, oxindole- and indandione-terminated quinoidal compounds tend to exhibit lower LUMO energy levels, making them promising for the construction of n-type semiconductors. The applications of conjugated polymers containing quinoidal structure in different optoelectronic devices also have been discussed. Such polymers have been widely used in organic thin-film transistors (OTFTs), organic solar cells (OSCs), and organic thermoelectric (OTE) devices. For example, electron mobility of above 1 cm2·V-1·s-1 in OTFTs has been obtained for the polymers; air stable n-type OTE devices with power factor above 4.24 μW·m-1·K-2 can be fabricated based on these polymers. Finally, the current problems and future development directions in the research process of quinoid based polymers are also discussed, hoping to provide useful information for the development of high-performance polymer semiconductor materials. The major issues for this field include: (1) development of new configuration-locking methods for the synthesis of isomer-free quinoid monomers; (2) development of new quinoidal monomers for the synthesis of conjugated polymers with LUMO energy levels below -4.4 eV; (3) synthesis of conjugated polymers using quinoid units for NIR-II photothermal therapy.关键词：Conjugated polymers;Quinoidal structures;Semiconductor materials;Low bandgap;Organic optoelectronic devices
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发布时间：2023-05-31 - 摘要：Self-assembly of block copolymers (BCPs) into microparticles has gained growing interest due to their various applications, which are dependent on the morphology of microparticles. Therefore, it is of great significance for the regulation of ordered structure of microspheres. The constraint effects exerted by the boundary of a confining space can reduce the number of metastable states of BCPs, leading to the formation of uniform and defect-free structures. Thus, the three-dimensional (3D) confined assembly of BCPs has been employed as a powerful approach to preparing BCP microparticles with controllable morphology. In this feature article, the progress in the preparation of polymeric microparticles through 3D confined self-assembly of BCPs was comprehensively reviewed. The strategies and mechanism for regulating the shape, topology, and internal structure of BCP microspheres were summarized. Moreover, the effects of microparticle morphology on their performance in functional carriers and optical materials were analyzed in depth. Finally, the key scientific problems and challenges in this field were discussed.关键词：Block copolymers;Confined assembly;Polymeric microparticles;Structure control;Function regulation
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发布时间：2023-05-31 - 摘要：In recent years, immunotherapy, as a new therapeutic method, received extensive attention in the field of tumor therapy due to the exciting therapeutic effects on many types of malignant tumors. Though the development of immunotherapy is in full swing, immunotherapy still faces many challenges, such as low immune response rate, immune related adverse events. Using drug delivery materials for targeted delivery immune agents is an effective means to solve the current problems of immunodrugs and further improve the therapeutic index. Compared to chemotherapeutic agents, the target, mechanism and mode of action of immune agents are different, which poses a new challenge to the design of drug delivery materials. In this paper, we summarized the challenges in the process of immunodrugs delivery, and introduced the design ideas and representative results of polymeric materials for immune drug delivery to the tumor and lymph nodes. For the delivery of immune drug to tumor, we firstly showed 3 types of nanoparticles——polypeptide-dexamethasone conjugate, aspirin polymeric prodrug and nano-assembly of bile acid receptor modulators for releasing the immunosuppression in the tumor site. Then we introduced the poly(lactic acid) block polyethyleneimine CpG loaded nanoparticles combination with oxaliplatin for inducing the immunogenic death and further enhancing the in situ antitumor immunity. Finally, we present the strategy of hierarchical delivery of immune agents to tumors and lymph nodes using supramolecular assembled programmable nanomedicine. Furthermore, the influence of drug release mode on the immune stimulation effect was explored by the implants crosslinked by poly(ethylene glycol) and polysaccharide. For the delivery of immune drug to lymph node, pathogen-mimicking polymeric nanoparticles were used for realizing the efficient reflux of antigen and adjuvant to lymph nodes, and polyethyleneimine derivatives with stimulator of interferon genes (STING) adjuvant function were synthesized for achieving the spatiotemporal synergy between activating antigen presenting cells and promoting antigen cross presentation. Finally, we forwarded the problems that need to be solved and the future research direction in the field of immunodrug delivery.关键词：Biomedical polymers;Drug delivery;Tumor therapy;Immunotherapy
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发布时间：2023-05-31 - 摘要：Owing to the excellent biocompatibility, chemical diversity and sequence dependent bioactivity, peptides/poly(amino acids) have been widely used in biomedical applications, especially in tumor theranostics. However, there are still certain drawback of peptide/poly(amino acid) to overcome for future clinical applications, such as limited optical properties, short half-life and fast clearance rate. In this feature article, we describe the sequence design, side chain modification and self-assembled spatial structure of peptide/poly(amino acid). Such factors endow them with additional optical properties and enhanced pharmacokinetic, pharmacodynamic and immunological properties. We focus on the applications of biomaterials self-assembled from peptides/poly(amino acids) in the aspect of tumor diagnosis and treatment. Additionally, we propose important challenges and future prospects of peptide/poly(amino acid)-based biomaterials for tumor diagnosis and treatment.关键词：Peptide;Poly(amino acid);Self-assembly;Tumor Theranostics
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发布时间：2023-05-31 - 摘要：Biosensors are devices that are sensitive to biological substances and convert their changes into monitorable optical and electrical signals. Owing to their remarkable advantages of high selectivity, fast analysis speed and high accuracy, they are widely applied in biomedical, environmental monitoring and food safety. Nanoprobes, which play vital roles in the output and amplification of signals, are the core components of biosensors. The signals of nanoprobes are intrinsically related to their morphology, surface chemistry and assembled structure. In this feature article, we summarized our research on the following three aspects: (1) Use of intelligent polymers to precisely regulate the synthesis of nanoprobes through three growth modes, such as intelligent growth mode, chemically anchored seed-growth mode and micellar limited growth mode. Up to now, we have customized more than 30 kinds of efficient biomedical probe materials; (2) Developed the intelligent multifunctional surface engineering strategies on probe materials, and achieved 1D, 2D and 3D self-assembly of nanoprobes by adjusting the dynamic and thermodynamic parameters; (3) Based on the designed probe materials, different types of biosensors such as SERS biosensor, fluorescent biosensor, electrochemical biosensor and colorimetric biosensor are constructed, and their applications in food safety detection and biomedical diagnosis are explored.关键词：Biosensors;Nanoprobes;Smart polymers;Precise synthesis;Controllable assembly
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发布时间：2023-05-31 - 摘要：With the unique one-dimensional structure, fiber shape energy storage batteries, represented by lithium-ion fiber batteries, play an important role in energy supplement for wearable devices. The diameter of lithium-ion fiber batteries usually lies between tens to hundreds of micrometers. The outstanding flexibility can accommodate multiple deformation such as bending, twisting, and stretching. By low-cost weaving method, lithium-ion fiber batteries can be easily weaved into energy storage fabrics and integrate with daily clothes. However, traditional fiber batteries suffer from inefficient preparation and poor performance matching, which can hardly move forward from laboratory to industrial production. In addition, researchers used to believe that with the increase of length, the internal resistance of fiber batteries also increase, which seriously hindered the theoretical development of large-scale fiber batteries. In this feature article, we briefly summarize the research progress of fiber shape energy storage devices in recent years. For practical application requirement, the development of flexible lithium-ion fiber batteries is sufficiently concluded based on the work of our group. Firstly, continuous manufacture of lithium-ion fiber batteries is discussed. Large-scale production of lithium-ion batteries was realized for the first time, which met the prerequisites of broad usage. The variation of internal resistance with length was revealed for the special 1D structure of fiber batteries. The electrochemical performance, mechanical properties, and tolerance performance were characterized under practical scenarios. Furthermore, based on continuously prepared lithium-ion fiber batteries, energy storage fabrics and integration with wearable devices are developed. This showed promising applications in healthcare, communication, and motion monitoring. Finally, the future of flexible fiber shape energy storage devices is prospected. Efforts should be devoted to improving the electrochemical performance of lithium-ion fiber batteries, such as energy density, power density and cycle performance. Besides, fiber battery pack technique should be investigated to adapt more real-life scenarios. Suitable application for energy storage fabrics are still awaited to be explored.关键词：Fiber battery;Continuous production;Energy storage fabrics;Integration
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发布时间：2023-05-31 - 摘要：As the representative of new thin-film solar cells, the photoelectric conversion efficiency of organic/perovskite solar cells has achieved a great breakthrough in the last decade. At the same time, due to its light-weight, flexibility and low-cost printable preparation by solution process, the new thin-film solar cells also show potential for flexible devices. Combined with other functional flexible electronic devices, the integrated design can meet people's growing living needs for portable mobile power and wearable devices. In recent years, the author's research team focused on the key scientific and technical issues of integrated design and printing of flexible thin-film solar cells, mainly aiming at the problems of the fragility of devices and the poor reproducibility of flexible printing morphology, carried out systematic research and obtained a series of innovative achievements. In this feature article, the design of flexible transparent electrode, the engineering control of flexible interface, the design of flexible toughening of active layer for photoelectric conversion and the strategy of large-area flexible printing are discussed, and the development of flexible thin-film solar cell modules is prospected.关键词：Organic solar cells;Perovskite photovoltaics;Flexible electronics;Shear printing;Bionic design
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发布时间：2023-05-31 - 摘要：Polymer photovoltaics have achieved considerable development in recent years, and the latest Y-series non-fullerene acceptors represented by Y6 have boosted the power conversion efficiencies to nearly 20%, while some of their working mechanisms have not yet been fully understood. This paper reviews the research reports on the charge generation mechanism of polymer photovoltaic systems based on fullerene acceptors and non-fullerene acceptors in recent years, and compares the similarities and differences of the working mechanisms of the two systems and the possible reasons for the high performance of the Y series. Generally, the polymer donor-fullerene acceptor systems can achieve ultrafast charge separation, but suffers from large energy loss, which limits the improvement of their performance; the polymer donor-non-fullerene acceptor systems show greatly reduced energy loss, but their charge generation process is relatively slow, and in some cases the assistance of thermal energy is required. Y series acceptors have unique molecular packing way and charge generation kinetics which both contribute to their remarkable performance, while the specific mechanism of charge generation is still controversial. Also, possible methods and prospects for further reducing energy loss and improving device performance are proposed. It is clear that nonradiative recombination losses must be further reduced to achieve higher device performances, possibly by improving the photoluminescence quantum efficiency and fine-tuning the kinetics of the interconversion between excited state and charge transfer state. Finally, continuous efforts on improving the long term stability of polymer photovoltaic devices are still needed to promote their commercialization in the future.关键词：Polymer photovoltaics;Non-fullerene acceptors;Charge generation;Charge recombination;Energy loss
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发布时间：2023-05-31 - 摘要：Thermally activated sensitized fluorescence (TSF) with thermally activated delayed fluorescence materials (TADF) as sensitizers and highly efficient conventional fluorescent dopants (CFD) as emitters was called the "fourth-generation luminescence technology" of organic light-emitting diodes (OLEDs), which can achieve 100% exciton utilization with low efficiency roll-off and narrowband emission simultaneously, compared with the traditional TADF emitters. The functionally separated materials of TSF-OLEDs are connected with each other by the rapid Förster energy transfer between sensitizer and dopant, further breaking the trade-off between effective up-conversion of triplet and impressive radiative decay of singlet. Herein, focusing on the keystone about how to realize the precise modulation and efficient utilization of excitons generated from carriers recombination, we systematically summarize the recent research progress of TSF in our group from the perspective of the efficiency, lifetime and purity of TSF-OLEDs. Starting from the luminescent mechanism of the TSF-OLEDs, we display some methods which can restrict the energy loss pathways to improve efficiency and suppress efficiency roll-off. Meanwhile, a series of sensitizers with through-space charge transfer characteristic and high stability of blue emission, and the designing strategies of many narrowband emitters including BN-MR, BODIPY and Indolocarbazole are illustrated. In addition, the construction of white-emission devices with high performance is demonstreted. Finally, the challenges and opportunities for the future development in TSF-OLEDs are also discussed.关键词：Thermally activated sensitized fluorescence;Thermally activated delayed fluorescence;Sensitizer;Narrowband emitter
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发布时间：2023-05-31 - 摘要：Efficient electrochemically active materials are one of the key materials for achieving high-performance electrochemical energy storage devices. How to precisely regulate the microstructure of electrode materials at the atomic level and develop effective synthesis methods to achieve structure-controlled synthesis are scientific problems of great interest and the frontier of basic research. With the advantages of rich physical and chemical structures and adjustable functional group types, polymers have become an important type of materials in modern industrial development. In particular, rigid aromatic heterocyclic polymer-based materials have been widely used in electrochemical energy storage in recent years because they contain aromatic heterocyclic structures, facilitate high-temperature polymerization, have high residual carbon rates, and have good elemental and morphological inheritance after carbonization. In this feature article, we summarized the applications of rigid aromatic heterocyclic polymer-based electrode materials in electrochemical energy storage devices such as supercapacitors, sodium-ion batteries, and lithium-sulfur batteries. In particular, we discussed a series of elemental and morphology-controlled polymer-based electrode materials created by our group through intrinsic doping. Finally, the future research directions of polymer-based materials in the field of energy are summarized and prospected.关键词：Polymers;Supercapacitors;Sodium-ion batteries;Lithium-Sulfur batteries;Aromatic heterocyclic polymers
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发布时间：2023-05-31
Feature Article
- 摘要：Peptide nanomedicines have great potential in tumor diagnosis and treatment due to their advantages of easy design and modification, good targeting, biocompatibility and long blood circulation time. In recent years, the strategy of constructing peptide nanomaterials in situ in the tumor microenvironment has been widely studied, and "in vivo self-assembly" has proven to be a promising biotechnology for disease diagnosis and treatment. Construction of in situ peptide-based self-assemblies at tumor or infection sites shows assembly/aggregation-induced retention (AIR) effects and enhances the biological function of nanomaterials. Peptide molecules are often driven by hydrogen bonds, van der Waals forces, electrostatic effects, etc. to form supramolecular structures. The self-assembly behavior is often stimulated by various factors such as light, sound, enzymes, redox, etc., to form a corresponding assembly structure. The tumor microenvironment is more complex, and researchers have designed a series of peptide nanomaterials that can respond to the special tumor microenvironment, so that the peptide nanomaterials can be assembled at the tumor site to achieve the expected therapeutic effect. The in vivo self-assembly strategy of peptide nanomaterials can better improve the ability of drug enrichment at target location, cell uptake of drug and drug penetration. At the same time, it has been found that peptide nanomaterials also have a gratifying effect in non-invasive biological imaging, and that this non-invasive imaging strategy has also been widely used, such as fluorescence imaging, photoacoustic imaging, etc. Based on the current research work on peptide nanomaterials, this article reviews the effects of in vivo self-assembled peptide nanomaterials on the diagnosis and treatment of tumors through different stimuli (pH, enzymes, redox, etc.), focusing on the design and synthesis of different stimuli-responsive self-assembled peptide nanomaterials and their applications in tumor diagnosis and treatment, such as the enhancement of drug enrichment, penetration, endocytosis and other processes in drug delivery systems. At the same time, its application in biological imaging is briefly introduced, and finally the future development of self-assembled peptide nanomaterials in vivo is prospected.关键词：In vivo self-assembly;Peptide nanomaterials;Stimulation responsiveness;Drug delivery;Tumor diagnosis and treatment
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发布时间：2023-05-31
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