The practical deployment of polyester-based solid electrolytes such as poly(ε-caprolactone)(PCL)is hindered by two inherent material-level constraints:the semicrystalline nature of PCL chains severely restricts segme...The practical deployment of polyester-based solid electrolytes such as poly(ε-caprolactone)(PCL)is hindered by two inherent material-level constraints:the semicrystalline nature of PCL chains severely restricts segmental mobility and limits ionic conductivity,whereas interfacial instability against lithium metal anodes jeopardizes long-term cycling.Based on orthogonal polymerization technology combined with electrolyte structural design concepts,this work achieved a one-step fabrication of a polyester-based block copolymer electrolyte(BCPE)system comprising fluorinated segments(PTFEA)and poly(ε-caprolactone)(PCL).Structurally,this design enables a dual breakthrough in electrochemical performance:on one hand,the introduction of fluorinated segments with steric hindrance effects can effectively disrupt the regular arrangement of the PCL main chain,reduce the crystallinity of PCL within the polymer electrolyte,and significantly enhance the segmental mobility of the polymer matrix;on the other hand,during the charge/discharge cycles of lithium batteries,fluorinated segments can induce the formation of a LiF-rich solid electrolyte interphase(SEI)through in situ decomposition reactions,achieving interface stabilization and homogeneous lithiumion deposition regulation.展开更多
Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effectiv...Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.展开更多
To precisely control intrachain π-electron delocalization and interchain interaction simultaneously is the prerequisite to obtain stable and efficient deep-blue light-emitting p-n polymer semiconductors for the polym...To precisely control intrachain π-electron delocalization and interchain interaction simultaneously is the prerequisite to obtain stable and efficient deep-blue light-emitting p-n polymer semiconductors for the polymer light-emitting diodes(PLEDs).Herein,we introduced the steric carbazole-fluorene nanogrid into light-emitting diphenyl sulfone-based p-n polymer semiconductors(PG and PDG) via metal-free C-N coupling polymerization for the fabrication of deep-blue PLEDs.The steric,rigid and twisted configuration between nanogrid and diphenyl sulfone in PG and PDG present the unique characteristic of large steric hindrance interaction to suppress interchain aggregation in solid state.Due to the different length of electron-deficient diphenyl sulfone monomers,PG showed a deep-blue emission with a maximum peak at 428 nm but red-shifted to 480 nm for the PDG films.Interestingly,similar deep-blue emission behavior of PG in diluted non-polar solution and films suggested the extremely weak interchain aggregation.Finally,PLEDs based on PG are fabricated with a stable deep-blue emission of CIE(0.15,0.10),and corresponding EL spectral profile is also completely identical to PL ones of diluted solution,revealed the intrachain emission without obvious interchain excited state,confirmed effectiveness of the steric hindrance functionalization of nanogrid in p-n polymer semiconductor for deep-blue light-emitting organic optoelectronics.展开更多
Objectives:Drug resistance is the major determinant of chemotherapy failure,leading to relapse and tumor progression,demonstrating the urgent need for novel antineoplastic drugs.This study aimed to evaluate the antica...Objectives:Drug resistance is the major determinant of chemotherapy failure,leading to relapse and tumor progression,demonstrating the urgent need for novel antineoplastic drugs.This study aimed to evaluate the anticancer potential of two novel pyrazole derivatives,P3C.1 and P3C.2,and to elucidate their mechanism of action in cancer cells.Methods:The cytotoxicity of the compounds was evaluated across 27 different cancer cell lines via a nuclear staining assay.Subsequent flow cytometric and biochemical analyses were performed to assess reactive oxygen species(ROS)generation,apoptosis induction,mitochondrial integrity,and cell cycle progression.Additional studies included transcriptome analyses and immunoassays to characterize the molecular mechanisms underlying drug activity.Results:Two novel pyrazole derivatives,P3C.1 and P3C.2,were identified with potent cytotoxicity on a variety of cancer cell lines.Among the adherent cell lines tested,the triple-negative breast cancer(TNBC)cell line MDA-MB-231 exhibited the highest sensitivity to both compounds and was therefore selected for further experimentation.In vitro assays demonstrated that both compounds induced ROS generation,mitochondrial membrane depolarization,cell cycle arrest and apoptosis.Whole-transcriptome sequencing of P3C.1 and P3C.2-treated MDA-MB-231 and two lymphoblastic leukemia cell lines revealed four genes in common associated with cell signaling and membrane dynamics.Connectivity Map(CMAP)database comparisons of shared genes for each cancer subtype revealed a strong similarity between the two compounds with tubulin inhibitors,and subsequent assays confirmed that these compounds act as microtubule-disrupting agents.Moreover,protein phosphorylation analysis indicated that both compounds induced hyperphosphorylation of JNK,and ERK1/2,along with hypophosphorylation of p38 kinases.Conclusions:P3C.1 and P3C.2 emerged as promising anti-breast cancer agents with dual mechanisms of action involving microtubule disruption and altered kinase signaling,leading to induction of apoptosis.展开更多
Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catal...Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.展开更多
Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford prod...Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford products with fixed sequences and compositions.Herein,we report the triethylborane/1,8-diazabicyclo[5.4.0]undec-7-ene(Et_3B/DBU)pair-mediated four-component switchable polymerization of propylene oxide(PO),CO_(2),phthalic anhydride(PA),and racemic lactide(rac-LA),which enables the on-demand synthesis of four different block copolymers,i.e.,poly(propylene phthalate)-b-polylactide(PPE-b-PLA),PPE-b-PLA-b-poly(propylene carbonate)(PPC),PPE-b-PPC-b-PLA,and PPE-b-PPCb-poly(propylene oxide)(PPO),through rationally modulating the Lewis pair(LP)ratio.Core to this protocol is that increasing the loading of Et_(3)B accelerates the ring-opening of PO while impeding the reactivity of rac-LA,thus allowing for fine-tuning of the thermodynamic and kinetic of the switchable polymerization.Therefore,the four polymerization cycles involving PO/PA ring-opening copolymerization(ROCOP),PO/CO_(2) ROCOP,rac-LA ring-opening polymerization(ROP),and PO ROP can be connected and discriminated in precisely programmed manners.展开更多
Aggregation-induced emission(AIE)polymers have been extensively studied;however,the integration of AIE units into polyelectrolytes remains largely limited by the laborious multistep synthesis of pre-designed emissive ...Aggregation-induced emission(AIE)polymers have been extensively studied;however,the integration of AIE units into polyelectrolytes remains largely limited by the laborious multistep synthesis of pre-designed emissive monomers.Herein,we report a one-pot multicomponent polymerization method that directly produces main-chain charged polyelectrolytes with intrinsic AIE characteristics from non-emissive building blocks.By optimizing the monomer structures and reaction conditions,a series of soluble high-molecular-weight polymers with welldefined backbones were obtained in high yields.The resulting polyelectrolytes displayed robust AIE behavior,exhibiting fluorescence enhancement up to about 60-fold in an aqueous environment,and maintained excellent thermal stability.Owing to their cationic backbones,these polymers interact strongly with microbial surfaces and exhibit remarkable antimicrobial activities.This study establishes a synthetically efficient route to AIE polyelectrolytes and highlights their potential applications as multifunctional materials for bioimaging,antimicrobial therapy,and other applications.展开更多
Thermosetting polymers exhibit outstanding mechanical properties,thermal stability,and chemical resistance due to their permanently cross-linked network structures.However,the irreversible nature of covalent cross-lin...Thermosetting polymers exhibit outstanding mechanical properties,thermal stability,and chemical resistance due to their permanently cross-linked network structures.However,the irreversible nature of covalent cross-linking renders these materials non-reprocessable and non-recyclable,posing significant environmental challenges.Although healable polymers based on dynamic covalent bonds and supramolecular interactions have emerged as promising alternatives,a broadly applicable strategy utilizing metal-ligand coordination in thermoset systems remains underexplored.In this work,we present a robust and healable thermoset system fabricated via ring-opening metathesis polymerization(ROMP)of commercially available chelating norbornene comonomers.Cross-linking is accomplished through O-donor coordination to Lewis acidic metal centers,yielding polydicyclopentadiene(PDCPD)-based networks that demonstrate high mechanical strength(up to 60.8 MPa)and effective self-healing performance.This methodology offers a simple and scalable approach to developing high-performance,sustainable thermosetting materials.展开更多
Organocatalyzed atom transfer radical polymerization(O-ATRP)is a pivotal technique for the synthesis of polymers with well-defined structures that are devoid of metallic residues.A major challenge in this area is the ...Organocatalyzed atom transfer radical polymerization(O-ATRP)is a pivotal technique for the synthesis of polymers with well-defined structures that are devoid of metallic residues.A major challenge in this area is the reduction of catalyst loading while maintaining precise control over polymer architecture and properties.Herein,we systematically evaluate the efficacy of six pyrazino[2,3-f][1,10]phenanthroline(pyzPhen)-based photoredox catalysts in photoinduced O-ATRP.Experimental results indicate that the introduction of various substituents markedly influences the photophysical properties and redox behavior of the catalysts,thereby resulting in differing catalytic efficiencies in the O-ATRP of methyl methacrylate(MMA).Following additional optimization,two highly efficient O-ATRP photocatalysts capable of exhibiting thermally activated delayed fluorescence(TADF)were successfully identified.Under visible light irradiation,TADF catalysts effectively mediated the controlled polymerization of MMA at a low loading level of 50 ppm,particularly when used in conjunction with the initiator DBMM.The catalytic systems demonstrate excellent temporal control,broad monomer applicability,and favorable compatibility with various initiators and solvent systems.This work offers new insights into the development of efficient,low-catalyst-loading,metal-free ATRP systems.展开更多
To achieve the target of carbon neutrality,it is crucial to develop an efficient and green synthesis methodology with good atomic economy to achieve sufficient utilization of energy and sustainable development.Photoin...To achieve the target of carbon neutrality,it is crucial to develop an efficient and green synthesis methodology with good atomic economy to achieve sufficient utilization of energy and sustainable development.Photoinduced electron transfer reversible addition-fragmentation chain-transfer(PET-RAFT)polymerization is a precise methodology for constructing polymers with well-defined structures.However,conventional semiconductor-mediated PET-RAFT polymerization still has considerable limitations in terms of efficiency as well as the polymerization environment.Herein,sulfur-doped carbonized polymer dots(CPDs)were hydrothermally synthesized for catalysis of aqueous PET-RAFT polymerization at unprecedented efficiency with a highest propagation rate of 5.05 h-1.The resulting polymers have well-controlled molecular weight and narrow molecular weight dispersion(Ð<1.10).Based on the optoelectronic characterizations,we obtained insights into the photoinduced electron transfer process and proposed the mechanism for CPD-mediated PET-RAFT polymerization.In addition,as-synthesized CPDs for PET-RAFT polymerization were also demonstrated to be suitable for a wide range of light sources(blue/green/solar irradiation),numerous monomers,low catalyst loading(low as 0.01 mg mL^(-1)),and multiple polar solvent environments,all of which allowed to achieve efficiencies much higher than those of existing semiconductor-mediated methods.Finally,the CPDs were confirmed to be non-cytotoxic and catalyzed PET-RAFT polymerization successfully in cell culture media,indicating broad prospects in biomedical fields.展开更多
Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In t...Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.展开更多
It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation...It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.展开更多
Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to p...Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to prevent degradation and side reactions.In the contribution,histidine N-thiocarboxyanhydride(His-NTA)is directly synthesized in aqueous solution without protection.With the self-catalysis of the imidazole side group,the ring-closing reaction to form His-NTA does not require any activating reagent(e.g.,phosphorus tribromide),which is elucidated by density functional theory(DFT)calculations.His-NTA directly polymerizes into PHis bearing unprotected imidazole groups with designable molecular weights(4.2-7.7 kg/mol)and low dispersities(1.10-1.19).Kinetic experiments and Monte Carlo simulations reveal the elementary reactions and the relationship between the conversion of His-NTA and time during polymerization.Block copolymerization of His-NTA with sarcosine N-thiocarboxyanhydride(Sar-NTA)demonstrate versatile construction of functional polypept(o)ides.The triblock copoly(amino acid)PHis-b-PSar-b-PHis is capable to reversibly coordinate with transition metal ions(Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+)and Zn^(2+))to form pH-sensitive hydrogels.展开更多
Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymeriza...Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymerization of o-phthalaldehyde(OPA)and epoxide using Lewis pair type two-component organocatalysts for producing acetal-functionalized polyether and polyurethane.Notably,triethylborane as the Lewis acid,in comparison with tri(n-butyl)borane,more effectively enhances the polymerization activity by mitigating borane-induced reduction of the aldehyde group into extra initiating(borinic ester)species.Density functional theory(DFT)calculations present comparable energy barriers of OPA-epoxide cross-propagation and epoxide self-propagation,which is consistent with the experimental finding that an alternating-rich copolymer comprising mostly OPA-epoxide units but also epoxide-epoxide linkages is produced.In particular,when epoxide is added in a large excess,the product becomes a polyether containing acetal functionalities in the central part of the backbone and thus being convertible into polyurethane with refined acid degradability.展开更多
Core-shell colloidal particles with a polymer layer have broad applications in different areas.Herein,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembl...Core-shell colloidal particles with a polymer layer have broad applications in different areas.Herein,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembly and photoinduced seeded reversible addition-fragmentation chain transfer(RAFT)polymerization to prepare a diverse set of core-shell colloidal particles with a well-defined polymer layer.Chemical compositions,structures,and thicknesses of polymer layers could be conveniently regulated by using different types of monomers and feed[monomer]/[chain transfer agent]ratios during seeded RAFT polymerization.展开更多
The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxya...The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxyanhydride(NCA)is conducted at relatively slow rates,requiring long tubing or ending up with low-molecular-weight polymers.Inspired by recent advances in accelerated NCA polymerization,we report the crown-ether-catalyzed,rapid synthesis of polypeptide materials in cosolvents in flow reactors.The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min,yielding well-defined polypeptides(up to 30 k Da)through a 20-cm tubing reactor.Additionally,random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer.We believe that this work highlights the accelerated polymerization design in flow polymerization processes,offering the continuous production of polypeptide materials.展开更多
Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteris...Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteristics.However,their inherently low ion transport efficiency poses a major challenge for their application in LMBs.To address this issue,covalent organic framework(COF)with their ordered ion transport channels,chemical stability,large specific surface area,and designable multifunctional sites has shown promising potential to enhance lithium-ion conduction.Here,we prepared an anionic COF,Tp Pa-COOLi,which can catalyze the ring-opening copolymerization of cyclic lactone monomers for the in situ fabrication of SPEs.The design leverages the high specific surface area of COF to facilitate the absorption of polymerization precursor and catalyze the polymerization within the pores,forming additional COF-polymer junctions that enhance ion transport pathways.The partial exfoliation of COF achieved through these junctions improved its dispersion within the polymer matrix,preserving ion transport channels and facilitating ion transport across COF grain boundaries.By controlling variables to alter the crystallinity of Tp Pa-COOLi and the presence of-COOLi substituents,Tp Pa-COOLi with partial long-range order and-COOLi substituents exhibited superior electrochemical performance.This research demonstrates the potential in constructing high-performance SPEs for LMBs.展开更多
Chain-growth radical polymerization of vinyl monomers is essential for producing a wide range of materials with properties tailored to specific applications.However,the inherent resistance of the polymer's C―C ba...Chain-growth radical polymerization of vinyl monomers is essential for producing a wide range of materials with properties tailored to specific applications.However,the inherent resistance of the polymer's C―C backbone to degradation raises significant concerns regarding long-term environmental persistence,which also limits their potential in biomedical applications.To address these challenges,researchers have developed strategies to either degrade preexisting vinyl polymers or incorporate cleavable units into the backbone to modify them with enhanced degradability.This review explores the various approaches aimed at achieving backbone degradability in chain-growth radical polymerization of vinyl monomers,while also highlighting future research directions for the development of application-driven degradable vinyl polymers.展开更多
In recent years,cellulose-based fluorescent polymers have received considerable attention.However,conventional modification methods face challenges such as insolubility in most solvents,fluorescence instability,and en...In recent years,cellulose-based fluorescent polymers have received considerable attention.However,conventional modification methods face challenges such as insolubility in most solvents,fluorescence instability,and environmental risks.In this study,a novel biosynthesis strategy was developed to fabricate fluorescent cellulose by adding fluorescent glucose derivatives to a bacterial fermentation broth.The metabolic activity of bacteria is utilized to achieve in situ polymerization of glucose and its derivatives during the synthesis of bacterial cellulose.Owing to the structural similarity between triphenylamine-modified glucose(TPA-Glc N)and glucose monomers,the TPA-Glc N were efficiently assimilated by the bacterial cells and incorporated into the cellulose matrix,resulting in a uniform distribution of fluorescence.The fluorescence color and intensity of the obtained cellulose could be adjusted by varying the amount of the fluorescent glucose derivatives.Compared to the fluorescent cellulose synthesized through physical dyeing,the fluorescence of the products obtained by in situ polymerization showed higher intensity and stability.Furthermore,fluorescent bacterial cellulose can be hydrolyzed into nanocellulose-based ink,which demonstrates exceptional anti-counterfeiting capabilities under UV light.This biosynthesis method not only overcomes the limitations of traditional modification techniques but also highlights the potential of microbial systems as platforms for synthesizing functional polymers.展开更多
Some novel manganese and nickel complexes were synthesized by reacting manganese(Ⅱ) dichloride and nickel(Ⅱ) dichloride with pyridyl-imine ligands differing in the nature of the substituents at the imino nitrogen at...Some novel manganese and nickel complexes were synthesized by reacting manganese(Ⅱ) dichloride and nickel(Ⅱ) dichloride with pyridyl-imine ligands differing in the nature of the substituents at the imino nitrogen atom. All the complexes were characterized by analytical and infrared data: for some of them single crystals were obtained, and their molecular structure was determined by X-ray diffraction. The complexes were used in association with methylaluminoxane(MAO) for the polymerization of 1,3-butadiene obtaining active and selective catalysts giving predominantly 1,2 polybutadiene in case of manganese catalysts and exclusively cis-1,4 polybutadiene in case of nickel catalysts.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52573079)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B21003).
文摘The practical deployment of polyester-based solid electrolytes such as poly(ε-caprolactone)(PCL)is hindered by two inherent material-level constraints:the semicrystalline nature of PCL chains severely restricts segmental mobility and limits ionic conductivity,whereas interfacial instability against lithium metal anodes jeopardizes long-term cycling.Based on orthogonal polymerization technology combined with electrolyte structural design concepts,this work achieved a one-step fabrication of a polyester-based block copolymer electrolyte(BCPE)system comprising fluorinated segments(PTFEA)and poly(ε-caprolactone)(PCL).Structurally,this design enables a dual breakthrough in electrochemical performance:on one hand,the introduction of fluorinated segments with steric hindrance effects can effectively disrupt the regular arrangement of the PCL main chain,reduce the crystallinity of PCL within the polymer electrolyte,and significantly enhance the segmental mobility of the polymer matrix;on the other hand,during the charge/discharge cycles of lithium batteries,fluorinated segments can induce the formation of a LiF-rich solid electrolyte interphase(SEI)through in situ decomposition reactions,achieving interface stabilization and homogeneous lithiumion deposition regulation.
基金financially supported by the National Natural Science Foundation of China(No.52473338)the National Natural Science Foundation of China(Nos.52173004 and 51873055)+3 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0540000)Advanced Materials-National Science and Technology Major Project(No.2025ZD0614000)Hebei Natural Science Foundation(No.E2022202015)Anhui Province Science and Technology Innovation Tackling Key Project(No.202423i08050025)。
文摘Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.
基金the support from the Jiangsu Provincial Senior Talent Program (Dengfeng,Jiangsu University)the support from the National Key R&D Program of China (No.2024YFB3612600)+3 种基金the National Natural Science Foundation of China (Nos.22275098,62288102)Basic Research Program of Jiangsu (No.BK20243057)the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications (No.NY222097)the National Natural Science Foundation of China (No.62205035)。
文摘To precisely control intrachain π-electron delocalization and interchain interaction simultaneously is the prerequisite to obtain stable and efficient deep-blue light-emitting p-n polymer semiconductors for the polymer light-emitting diodes(PLEDs).Herein,we introduced the steric carbazole-fluorene nanogrid into light-emitting diphenyl sulfone-based p-n polymer semiconductors(PG and PDG) via metal-free C-N coupling polymerization for the fabrication of deep-blue PLEDs.The steric,rigid and twisted configuration between nanogrid and diphenyl sulfone in PG and PDG present the unique characteristic of large steric hindrance interaction to suppress interchain aggregation in solid state.Due to the different length of electron-deficient diphenyl sulfone monomers,PG showed a deep-blue emission with a maximum peak at 428 nm but red-shifted to 480 nm for the PDG films.Interestingly,similar deep-blue emission behavior of PG in diluted non-polar solution and films suggested the extremely weak interchain aggregation.Finally,PLEDs based on PG are fabricated with a stable deep-blue emission of CIE(0.15,0.10),and corresponding EL spectral profile is also completely identical to PL ones of diluted solution,revealed the intrachain emission without obvious interchain excited state,confirmed effectiveness of the steric hindrance functionalization of nanogrid in p-n polymer semiconductor for deep-blue light-emitting organic optoelectronics.
基金supported by NIH grant 1R16GM149379 to Renato J.Aguilerasupported by the core facilities of the BBRC,funded by the Research Centers in Minority Institutions grant 5U54MD007592 from the National Institute on Minority Health and Health Disparities to Robert A.Kirkensupported Denisse A.Gutierrez,Ana P.Betancourt,Elisa Robles-Escajeda and Armando Varela-Ramirez。
文摘Objectives:Drug resistance is the major determinant of chemotherapy failure,leading to relapse and tumor progression,demonstrating the urgent need for novel antineoplastic drugs.This study aimed to evaluate the anticancer potential of two novel pyrazole derivatives,P3C.1 and P3C.2,and to elucidate their mechanism of action in cancer cells.Methods:The cytotoxicity of the compounds was evaluated across 27 different cancer cell lines via a nuclear staining assay.Subsequent flow cytometric and biochemical analyses were performed to assess reactive oxygen species(ROS)generation,apoptosis induction,mitochondrial integrity,and cell cycle progression.Additional studies included transcriptome analyses and immunoassays to characterize the molecular mechanisms underlying drug activity.Results:Two novel pyrazole derivatives,P3C.1 and P3C.2,were identified with potent cytotoxicity on a variety of cancer cell lines.Among the adherent cell lines tested,the triple-negative breast cancer(TNBC)cell line MDA-MB-231 exhibited the highest sensitivity to both compounds and was therefore selected for further experimentation.In vitro assays demonstrated that both compounds induced ROS generation,mitochondrial membrane depolarization,cell cycle arrest and apoptosis.Whole-transcriptome sequencing of P3C.1 and P3C.2-treated MDA-MB-231 and two lymphoblastic leukemia cell lines revealed four genes in common associated with cell signaling and membrane dynamics.Connectivity Map(CMAP)database comparisons of shared genes for each cancer subtype revealed a strong similarity between the two compounds with tubulin inhibitors,and subsequent assays confirmed that these compounds act as microtubule-disrupting agents.Moreover,protein phosphorylation analysis indicated that both compounds induced hyperphosphorylation of JNK,and ERK1/2,along with hypophosphorylation of p38 kinases.Conclusions:P3C.1 and P3C.2 emerged as promising anti-breast cancer agents with dual mechanisms of action involving microtubule disruption and altered kinase signaling,leading to induction of apoptosis.
基金financial support from the National Natural Science Foundation of China(Nos.22401274,U23B6011)the Jilin Provincial Science and Technology Department Program(No.20250102070JC)。
文摘Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.
基金financially supported by National Key R&D Program Young Scientists Project(No.2023YFC3903100)the National Natural Science Foundation of China(No.22322503)analytical and testing assistance from the Analysis and Testing Center of HUST。
文摘Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford products with fixed sequences and compositions.Herein,we report the triethylborane/1,8-diazabicyclo[5.4.0]undec-7-ene(Et_3B/DBU)pair-mediated four-component switchable polymerization of propylene oxide(PO),CO_(2),phthalic anhydride(PA),and racemic lactide(rac-LA),which enables the on-demand synthesis of four different block copolymers,i.e.,poly(propylene phthalate)-b-polylactide(PPE-b-PLA),PPE-b-PLA-b-poly(propylene carbonate)(PPC),PPE-b-PPC-b-PLA,and PPE-b-PPCb-poly(propylene oxide)(PPO),through rationally modulating the Lewis pair(LP)ratio.Core to this protocol is that increasing the loading of Et_(3)B accelerates the ring-opening of PO while impeding the reactivity of rac-LA,thus allowing for fine-tuning of the thermodynamic and kinetic of the switchable polymerization.Therefore,the four polymerization cycles involving PO/PA ring-opening copolymerization(ROCOP),PO/CO_(2) ROCOP,rac-LA ring-opening polymerization(ROP),and PO ROP can be connected and discriminated in precisely programmed manners.
基金supported by the National Natural Science Foundation of China(No.22431004)Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates(No.2023B1212060003)。
文摘Aggregation-induced emission(AIE)polymers have been extensively studied;however,the integration of AIE units into polyelectrolytes remains largely limited by the laborious multistep synthesis of pre-designed emissive monomers.Herein,we report a one-pot multicomponent polymerization method that directly produces main-chain charged polyelectrolytes with intrinsic AIE characteristics from non-emissive building blocks.By optimizing the monomer structures and reaction conditions,a series of soluble high-molecular-weight polymers with welldefined backbones were obtained in high yields.The resulting polyelectrolytes displayed robust AIE behavior,exhibiting fluorescence enhancement up to about 60-fold in an aqueous environment,and maintained excellent thermal stability.Owing to their cationic backbones,these polymers interact strongly with microbial surfaces and exhibit remarkable antimicrobial activities.This study establishes a synthetically efficient route to AIE polyelectrolytes and highlights their potential applications as multifunctional materials for bioimaging,antimicrobial therapy,and other applications.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0540000)the National Natural Science Foundation of China(Nos.22301294,52025031 and 22261142664)the USTC Research Funds of the Double First-Class Initiative(No.YD9990002030)。
文摘Thermosetting polymers exhibit outstanding mechanical properties,thermal stability,and chemical resistance due to their permanently cross-linked network structures.However,the irreversible nature of covalent cross-linking renders these materials non-reprocessable and non-recyclable,posing significant environmental challenges.Although healable polymers based on dynamic covalent bonds and supramolecular interactions have emerged as promising alternatives,a broadly applicable strategy utilizing metal-ligand coordination in thermoset systems remains underexplored.In this work,we present a robust and healable thermoset system fabricated via ring-opening metathesis polymerization(ROMP)of commercially available chelating norbornene comonomers.Cross-linking is accomplished through O-donor coordination to Lewis acidic metal centers,yielding polydicyclopentadiene(PDCPD)-based networks that demonstrate high mechanical strength(up to 60.8 MPa)and effective self-healing performance.This methodology offers a simple and scalable approach to developing high-performance,sustainable thermosetting materials.
基金financially supported by the National Natural Science Foundation of China (No. 22271044).
文摘Organocatalyzed atom transfer radical polymerization(O-ATRP)is a pivotal technique for the synthesis of polymers with well-defined structures that are devoid of metallic residues.A major challenge in this area is the reduction of catalyst loading while maintaining precise control over polymer architecture and properties.Herein,we systematically evaluate the efficacy of six pyrazino[2,3-f][1,10]phenanthroline(pyzPhen)-based photoredox catalysts in photoinduced O-ATRP.Experimental results indicate that the introduction of various substituents markedly influences the photophysical properties and redox behavior of the catalysts,thereby resulting in differing catalytic efficiencies in the O-ATRP of methyl methacrylate(MMA).Following additional optimization,two highly efficient O-ATRP photocatalysts capable of exhibiting thermally activated delayed fluorescence(TADF)were successfully identified.Under visible light irradiation,TADF catalysts effectively mediated the controlled polymerization of MMA at a low loading level of 50 ppm,particularly when used in conjunction with the initiator DBMM.The catalytic systems demonstrate excellent temporal control,broad monomer applicability,and favorable compatibility with various initiators and solvent systems.This work offers new insights into the development of efficient,low-catalyst-loading,metal-free ATRP systems.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant No.22035001 and No.52233005.
文摘To achieve the target of carbon neutrality,it is crucial to develop an efficient and green synthesis methodology with good atomic economy to achieve sufficient utilization of energy and sustainable development.Photoinduced electron transfer reversible addition-fragmentation chain-transfer(PET-RAFT)polymerization is a precise methodology for constructing polymers with well-defined structures.However,conventional semiconductor-mediated PET-RAFT polymerization still has considerable limitations in terms of efficiency as well as the polymerization environment.Herein,sulfur-doped carbonized polymer dots(CPDs)were hydrothermally synthesized for catalysis of aqueous PET-RAFT polymerization at unprecedented efficiency with a highest propagation rate of 5.05 h-1.The resulting polymers have well-controlled molecular weight and narrow molecular weight dispersion(Ð<1.10).Based on the optoelectronic characterizations,we obtained insights into the photoinduced electron transfer process and proposed the mechanism for CPD-mediated PET-RAFT polymerization.In addition,as-synthesized CPDs for PET-RAFT polymerization were also demonstrated to be suitable for a wide range of light sources(blue/green/solar irradiation),numerous monomers,low catalyst loading(low as 0.01 mg mL^(-1)),and multiple polar solvent environments,all of which allowed to achieve efficiencies much higher than those of existing semiconductor-mediated methods.Finally,the CPDs were confirmed to be non-cytotoxic and catalyzed PET-RAFT polymerization successfully in cell culture media,indicating broad prospects in biomedical fields.
基金financially supported by the National Natural Science Foundation of China(No.21172269)the Fundamental Research Funds for the Central Universities,SouthCentral Minzu University(No.CZH24005)。
文摘Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.
基金supported by the Fundamental Research Funds for Central Universities(No.30922010811).
文摘It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.
基金financially supported by the National Natural Science Foundation of China(Nos.22271252 and 22201105)。
文摘Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to prevent degradation and side reactions.In the contribution,histidine N-thiocarboxyanhydride(His-NTA)is directly synthesized in aqueous solution without protection.With the self-catalysis of the imidazole side group,the ring-closing reaction to form His-NTA does not require any activating reagent(e.g.,phosphorus tribromide),which is elucidated by density functional theory(DFT)calculations.His-NTA directly polymerizes into PHis bearing unprotected imidazole groups with designable molecular weights(4.2-7.7 kg/mol)and low dispersities(1.10-1.19).Kinetic experiments and Monte Carlo simulations reveal the elementary reactions and the relationship between the conversion of His-NTA and time during polymerization.Block copolymerization of His-NTA with sarcosine N-thiocarboxyanhydride(Sar-NTA)demonstrate versatile construction of functional polypept(o)ides.The triblock copoly(amino acid)PHis-b-PSar-b-PHis is capable to reversibly coordinate with transition metal ions(Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+)and Zn^(2+))to form pH-sensitive hydrogels.
基金financially supported by the National Key R&D Program of China(No.2022YFC2805103)the National Natural Science Foundation of China(Nos.52022031 and 52263001)the Foundation from Qinghai Science and Technology Department(No.2022-ZJ-944Q)。
文摘Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymerization of o-phthalaldehyde(OPA)and epoxide using Lewis pair type two-component organocatalysts for producing acetal-functionalized polyether and polyurethane.Notably,triethylborane as the Lewis acid,in comparison with tri(n-butyl)borane,more effectively enhances the polymerization activity by mitigating borane-induced reduction of the aldehyde group into extra initiating(borinic ester)species.Density functional theory(DFT)calculations present comparable energy barriers of OPA-epoxide cross-propagation and epoxide self-propagation,which is consistent with the experimental finding that an alternating-rich copolymer comprising mostly OPA-epoxide units but also epoxide-epoxide linkages is produced.In particular,when epoxide is added in a large excess,the product becomes a polyether containing acetal functionalities in the central part of the backbone and thus being convertible into polyurethane with refined acid degradability.
基金support from the Science and Technology Program of Guangzhou(No.2024A04J2821)the National Natural Science Foundation of China(Nos.52222301,22171055)the Guangdong Natural Science Foundation for Distinguished Young Scholar(No.2022B1515020078)。
文摘Core-shell colloidal particles with a polymer layer have broad applications in different areas.Herein,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembly and photoinduced seeded reversible addition-fragmentation chain transfer(RAFT)polymerization to prepare a diverse set of core-shell colloidal particles with a well-defined polymer layer.Chemical compositions,structures,and thicknesses of polymer layers could be conveniently regulated by using different types of monomers and feed[monomer]/[chain transfer agent]ratios during seeded RAFT polymerization.
基金financially supported by the National Natural Science Foundation of China(No.22101194)Natural Science Foundation of Jiangsu Province(No.BK20210733)+3 种基金Suzhou Municipal Science and Technology Bureau(No.ZXL2021447)Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxyanhydride(NCA)is conducted at relatively slow rates,requiring long tubing or ending up with low-molecular-weight polymers.Inspired by recent advances in accelerated NCA polymerization,we report the crown-ether-catalyzed,rapid synthesis of polypeptide materials in cosolvents in flow reactors.The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min,yielding well-defined polypeptides(up to 30 k Da)through a 20-cm tubing reactor.Additionally,random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer.We believe that this work highlights the accelerated polymerization design in flow polymerization processes,offering the continuous production of polypeptide materials.
基金the National Natural Science Foundation of China(grant nos.52020105012 and 523B2025)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)the Analysis and Testing Center of HUST for the assistance in analysis and testing。
文摘Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteristics.However,their inherently low ion transport efficiency poses a major challenge for their application in LMBs.To address this issue,covalent organic framework(COF)with their ordered ion transport channels,chemical stability,large specific surface area,and designable multifunctional sites has shown promising potential to enhance lithium-ion conduction.Here,we prepared an anionic COF,Tp Pa-COOLi,which can catalyze the ring-opening copolymerization of cyclic lactone monomers for the in situ fabrication of SPEs.The design leverages the high specific surface area of COF to facilitate the absorption of polymerization precursor and catalyze the polymerization within the pores,forming additional COF-polymer junctions that enhance ion transport pathways.The partial exfoliation of COF achieved through these junctions improved its dispersion within the polymer matrix,preserving ion transport channels and facilitating ion transport across COF grain boundaries.By controlling variables to alter the crystallinity of Tp Pa-COOLi and the presence of-COOLi substituents,Tp Pa-COOLi with partial long-range order and-COOLi substituents exhibited superior electrochemical performance.This research demonstrates the potential in constructing high-performance SPEs for LMBs.
基金funding from the National Natural Science Foundation of China(No.22401037)funding from JST CREST(No.JPMJCR23L1)。
文摘Chain-growth radical polymerization of vinyl monomers is essential for producing a wide range of materials with properties tailored to specific applications.However,the inherent resistance of the polymer's C―C backbone to degradation raises significant concerns regarding long-term environmental persistence,which also limits their potential in biomedical applications.To address these challenges,researchers have developed strategies to either degrade preexisting vinyl polymers or incorporate cleavable units into the backbone to modify them with enhanced degradability.This review explores the various approaches aimed at achieving backbone degradability in chain-growth radical polymerization of vinyl monomers,while also highlighting future research directions for the development of application-driven degradable vinyl polymers.
基金supported by the National Natural Science Foundation of China(No.22376111)Shandong Provincial Natural Science Foundation(No.ZR2024YQ026)+2 种基金for Excellent Young Scholars,Taishan Scholar Foundation of Shandong Province(No.tsqn202408237)Youth Innovation Team Project for Talent Introduction and Cultivation in Universities of Shandong Province(No.096-1622002)the Research Foundation for Distinguished Scholars of Qingdao Agricultural University(No.663-1117015)。
文摘In recent years,cellulose-based fluorescent polymers have received considerable attention.However,conventional modification methods face challenges such as insolubility in most solvents,fluorescence instability,and environmental risks.In this study,a novel biosynthesis strategy was developed to fabricate fluorescent cellulose by adding fluorescent glucose derivatives to a bacterial fermentation broth.The metabolic activity of bacteria is utilized to achieve in situ polymerization of glucose and its derivatives during the synthesis of bacterial cellulose.Owing to the structural similarity between triphenylamine-modified glucose(TPA-Glc N)and glucose monomers,the TPA-Glc N were efficiently assimilated by the bacterial cells and incorporated into the cellulose matrix,resulting in a uniform distribution of fluorescence.The fluorescence color and intensity of the obtained cellulose could be adjusted by varying the amount of the fluorescent glucose derivatives.Compared to the fluorescent cellulose synthesized through physical dyeing,the fluorescence of the products obtained by in situ polymerization showed higher intensity and stability.Furthermore,fluorescent bacterial cellulose can be hydrolyzed into nanocellulose-based ink,which demonstrates exceptional anti-counterfeiting capabilities under UV light.This biosynthesis method not only overcomes the limitations of traditional modification techniques but also highlights the potential of microbial systems as platforms for synthesizing functional polymers.
文摘Some novel manganese and nickel complexes were synthesized by reacting manganese(Ⅱ) dichloride and nickel(Ⅱ) dichloride with pyridyl-imine ligands differing in the nature of the substituents at the imino nitrogen atom. All the complexes were characterized by analytical and infrared data: for some of them single crystals were obtained, and their molecular structure was determined by X-ray diffraction. The complexes were used in association with methylaluminoxane(MAO) for the polymerization of 1,3-butadiene obtaining active and selective catalysts giving predominantly 1,2 polybutadiene in case of manganese catalysts and exclusively cis-1,4 polybutadiene in case of nickel catalysts.
