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
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
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
As a powerful synthetic tool,ruthenium-catalyzed ring-opening metathesis polymerization(ROMP)has been widely utilized to prepare diverse heteroatom-containing polymers.In this contribution,we report the synthesis of t...As a powerful synthetic tool,ruthenium-catalyzed ring-opening metathesis polymerization(ROMP)has been widely utilized to prepare diverse heteroatom-containing polymers.In this contribution,we report the synthesis of the novel imine-based polymer through the copolymerization of cyclooctene with cyclic imine comonomer via ROMP.Because of the efficient hydrolysis reactions of the imine group,the generated copolymer can be easily degraded under mild condition.Moreover,the generated degradable product was the telechelic polymer bearing amine group,which was highly challenged for its direct synthesis.And this telechelic polymer could also be used for the further synthesis of new polymer through post-transformation.The introduction of imine unit in this work provides a new example of the degradable polymer synthesis.展开更多
Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great signif...Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.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
Polymerization-induced self-assembly(PISA)has become one of the most versatile approaches for scalable preparation of linear block copolymer nanoparticles with various morphologies.However,the controlled introduction ...Polymerization-induced self-assembly(PISA)has become one of the most versatile approaches for scalable preparation of linear block copolymer nanoparticles with various morphologies.However,the controlled introduction of branching into the core-forming block and the effect on the morphologies of block copolymer nanoparticles under PISA conditions have rarely been explored.Herein,a series of multifunctional macromolecular chain transfer agents(macro-CTAs)were first synthesized by a two-step green light-activated photoiniferter polymerization using two types of chain transfer monomers(CTMs).These macro-CTAs were then used to mediate reversible addition-fragmentation chain transfer(RAFT)dispersion polymerization of styrene(St)to prepare block copolymers with different core-forming block structures and the assemblies.The effect of the core-forming block structure on the morphology of block copolymer nanoparticles was investigated in detail.Transmission electron microscopy(TEM)analysis indicated that the brush-like core-forming block structure facilitated the formation of higher-order morphologies,while the branched core-forming block structure favored the formation of lower-order morphologies.Moreover,it was found that using macroCTAs with a shorter length also promoted the formation of higher-order morphologies.Finally,structures of block copolymers and the assemblies were further controlled by changing the structure of macro-CTA or using a binary mixture of two different macro-CTAs.We expect that this work not only sheds light on the synthesis of block copolymer nanoparticles but also provide important mechanistic insights into PISA of nonlinear block copolymers.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
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
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
The performance of hydrogel radical polymerization under ambient conditions is a major challenge because oxygen is an effective radical quencher and the steps to remove or neutralize it are time consuming and laboriou...The performance of hydrogel radical polymerization under ambient conditions is a major challenge because oxygen is an effective radical quencher and the steps to remove or neutralize it are time consuming and laborious.A self-initiating system consisting of transition metals and acetylacetone has been successfully developed.The system is capable of initiating free radical polymerization of hydrogels at room temperature under aerobic conditions,which is attributed to carbon radicals generated by the oxidation of acetylacetone.Some of these carbon radicals reduce oxygen to generate hydroxyl radicals,which together induce self-coagulation of hydrogels.The polymerization system was effective for a variety of monomer and hydrogel swelling and shrinking schemes,and the reaction remained successful when exposed to saturated oxygen.In conclusion,the results demonstrate that the present strategy is an effective approach to addressing the challenge of deoxygenation in polymer synthesis,and provides a convenient method for synthesizing multifunctional hydrogels under ambient conditions.展开更多
Copolymers of fluoroethylene and vinyl ethers(FEVE)are soluble and curable at relatively low temperature,and are used as high-performance coatings and paints.Currently,most market-available FEVE products obtained thro...Copolymers of fluoroethylene and vinyl ethers(FEVE)are soluble and curable at relatively low temperature,and are used as high-performance coatings and paints.Currently,most market-available FEVE products obtained through solution polymerization contain a large fraction of organic solvent,and hence,volatile organic compound(VOC)emissions cause environmental issues.In this study,the emulsion copolymerization of chlorotrifluoroethylene(CTFE)and vinyl ethers using an environmentally friendly emulsification system to produce waterborne FEVE was investigated.In addition to mixed nonionic and ionic surfactants,macromolecular monomer with double bond and polyoxyethylene segments were used in the emulsification system.The effect of adding macromolecular monomer and polyoxyethylene segment length of the nonionic surfactant on emulsion copolymerization were analyzed.An optimized emulsifier system for FEVE is proposed,and the prepared FEVE latexes exhibit excellent storage stability and film formation ability.展开更多
Exploration of new green polymerization strategies for the construction of conjugated polymers is important but challengeable.In this work,a multicomponent polymerization of acetylarenes,alkynones and ammonium acetate...Exploration of new green polymerization strategies for the construction of conjugated polymers is important but challengeable.In this work,a multicomponent polymerization of acetylarenes,alkynones and ammonium acetate for in situ construction of conjugated poly(triarylpyridine)s was developed.The polymerization reactions of diacetylarenes,aromatic dialkynones and NH_(4)OAc were performed in dimethylsulfoxide(DMSO)under heating in the presence of potassium tert-butoxide(t-BuOK),affording four conjugated poly(2,4,6-triarylpyridine)s(PTAPs)in satisfactory yields.The resulting PTAPs have good solubility in common organic solvents and high thermal stability with 5%weight loss temperatures reaching up to 460℃.They are also electrochemically active.The PTAPs incorporating tetraphenylethene units manifest aggregation-induced emission features.Moreover,through simply being doped into poly(vinyl alcohol)(PVA)matrix,the polymer and model compound containing triphenylamine moieties exhibit room-temperature phosphorescence properties with ultralong lifetimes up to 696.2 ms and high quantum yields up to 28.7%.This work not only provides a facile green synthetic route for conjugated polymers but also offers new insights into the design of advanced materials with unique photophysical properties.展开更多
Living cationic polymerization of 4-acetoxystyrene(STO)was conducted in CH_(2)Cl_(2) at-15℃ using a dicumyl chloride(DCC)/SnCl_(4)/nBu_(4)NBr initiating system.Impurity moisture initiation was inhibited by adding pro...Living cationic polymerization of 4-acetoxystyrene(STO)was conducted in CH_(2)Cl_(2) at-15℃ using a dicumyl chloride(DCC)/SnCl_(4)/nBu_(4)NBr initiating system.Impurity moisture initiation was inhibited by adding proton trap 2,6-di-tert-butylpyridine(DTBP),and the controlled initiation of DCC was confirmed by ^(1)H nuclear magnetic resonance(^(1)H-NMR)spectroscopy and matrix-assisted laser desorption ionization time-offlight mass(MALDI-TOF-MS)spectrometry.The polymerization kinetics were analyzed to for optimizing the polymerization rate.Allyl-telechelic PSTOs(allyl-PSTO-allyl)with molecular weight(Mn)range of 3540–7800 g/mol and narrow molecular weight dispersity(Mw/Mn)about 1.25 were prepared through nucleophilic substitution with allyltrimethylsilane(ATMS)at approximately 40%monomer conversion.The experimental results indicate that the substitution efficiency of ATMS increased with higher ATMS concentration,temperature,and extended reaction time.Nearly unity ally-functionality for allyl-PSTO-allyl was achieved by adding sufficient SnCl_(4) prior to the substitution.展开更多
As a key process in the manufacturing of hollow turbine blades for aeroengines,ceramic-core stereolithography(SL)is vital for the structural design and precise performance control of hollow turbine blades for aeroengi...As a key process in the manufacturing of hollow turbine blades for aeroengines,ceramic-core stereolithography(SL)is vital for the structural design and precise performance control of hollow turbine blades for aeroengines.Based on SL and digital light processing(DLP),ceramic SL has technical advantages such as high flexibility,short process flow,and integrated structure-performance manufacturing,making it ideal for manufacturing complex hollow ceramic cores.Currently,ceramic cores produced using this technology still encounter several challenges such as low bending strength,low dimensional accuracy,significant sintering shrinkage,and poor surface quality,which limit the innovative development and engineering applications of the additive manufacturing of UV-cured ceramics.This paper reviews the development of additive manufacturing technology and equipment for the vat polymerization of ceramic cores used in aeroengine blades and summarizes the principles and characteristics of vat polymerization for manufacturing ceramic cores.It also highlights research progress in lightweight structural design methods for ceramic cores,ceramic slurry preparation processes,SL processes,debinding and sintering processes,integration of forming system equipment,and verification of aeroengine blade casting.A comprehensive performance control strategy for the SL of ceramic cores is proposed,and future development directions and trends in ceramic-core fabrication using SL technology are discussed.展开更多
Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the ...Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.展开更多
The designing and manufacturing of micro/nanoscale tools for delivery,diagnostic,and therapeutic are essential for their multiscale integration in the precision medicine field.Conventional three-dimensional(3D)printin...The designing and manufacturing of micro/nanoscale tools for delivery,diagnostic,and therapeutic are essential for their multiscale integration in the precision medicine field.Conventional three-dimensional(3D)printing approaches are not suitable for such kind of tools due to the accuracy limitation.Multiphoton polymerization(MPP)-based micro/nanomanufacturing is a noncontact,high-precision molding technology that has been widely used in the micro/nano field is a promising tool for micro/nanoscale related precision medicine.In this article the fundamentals of MPP-based technology and the required materials in precision medicine are overviewed.The biomedical applications in various scenarios are then summarized and categorized as delivery systems,microtissue modeling,surgery,and diagnosis.Finally,the existing challenges and future perspectives on MPP-based micro/nanomanufacturing for precision medicine are discussed,focusing on material design,process optimization,and practical applications to overcome its current limitations.展开更多
Photoredox-mediated reversible-deactivation radical polymerization(RDRP)is an effective approach to synthesize polymers with defined composition and architecture.Current photoinduced RDRP primarily depends on outer-sp...Photoredox-mediated reversible-deactivation radical polymerization(RDRP)is an effective approach to synthesize polymers with defined composition and architecture.Current photoinduced RDRP primarily depends on outer-sphere electron transfer or homolysis mechanisms.Herein,we describe an example of iodine-mediated RDRP facilitated by photoinduced charge transfer complex(CTC)catalysis.The approach uses cheap and easily accessible N^(-)heterocyclic nitrenium salt(NHN^(+)...I^(-))as the photoactive CTC.Upon the irradiation of visible light,NHN^(+)...I^(-)undergoes single electron transfer to generate NHN·and I·radicals.The NHN·radical activates dormant Pn-I polymers via inner-sphere single electron transfer,leading to the propagating Pn·radical for chain growth and the I^(-)anion for recovering the CTC,and the I·radical deactivates the polymerization via coupling with Pn·.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
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 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financially supported by National Key R&D Program of China(No.2021YFA1501700)CAS Project for Young Scientists in Basic Research(No.YSBR-094)+1 种基金Natural Science Foundation of Anhui Province(Nos.2308085Y35 and 2023AH030002)Hefei Natural Science Foundation(No.202304)。
文摘As a powerful synthetic tool,ruthenium-catalyzed ring-opening metathesis polymerization(ROMP)has been widely utilized to prepare diverse heteroatom-containing polymers.In this contribution,we report the synthesis of the novel imine-based polymer through the copolymerization of cyclooctene with cyclic imine comonomer via ROMP.Because of the efficient hydrolysis reactions of the imine group,the generated copolymer can be easily degraded under mild condition.Moreover,the generated degradable product was the telechelic polymer bearing amine group,which was highly challenged for its direct synthesis.And this telechelic polymer could also be used for the further synthesis of new polymer through post-transformation.The introduction of imine unit in this work provides a new example of the degradable polymer synthesis.
基金financially supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22001078).
文摘Functional hyperbranched polymers,as an important class of materials,are widely applied in diverse areas.Therefore,the development of simple and efficient reactions to prepare hyperbranched polymers is of great significance.In this work,trialdehydes,diamines,and trimethylsilyl cyanide could easily undergo multicomponent polymerization under mild conditions,producing hyperbranched poly(α-aminonitrile)s with high molecular weights(M_(w) up to 4.87×10^(4))in good yields(up to 85%).The hyperbranched poly(α-aminonitrile)s have good solubility in commonly used organic solvents,high thermal stability as well as morphological stability.Furthermore,due to the numerous aldehyde groups in their branched chains,these hb-poly(α-aminonitrile)s can undergo one-pot,two-step,four-component post-polymerization with high efficiency.This work not only confirms the efficiency of our established catalyst-free multicomponent polymerization of aldehydes,amines and trimethylsilyl cyanide,but also provides a versatile and powerful platform for the preparation of functional hyperbranched polymeric materials.
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financially supported by the National Natural Science Foundation of China(Nos.22171055 and 52222301)the Guangdong Natural Science Foundation for Distinguished Young Scholar(No.2022B1515020078)the Science and Technology Program of Guangzhou(No.2024A04J2821)。
文摘Polymerization-induced self-assembly(PISA)has become one of the most versatile approaches for scalable preparation of linear block copolymer nanoparticles with various morphologies.However,the controlled introduction of branching into the core-forming block and the effect on the morphologies of block copolymer nanoparticles under PISA conditions have rarely been explored.Herein,a series of multifunctional macromolecular chain transfer agents(macro-CTAs)were first synthesized by a two-step green light-activated photoiniferter polymerization using two types of chain transfer monomers(CTMs).These macro-CTAs were then used to mediate reversible addition-fragmentation chain transfer(RAFT)dispersion polymerization of styrene(St)to prepare block copolymers with different core-forming block structures and the assemblies.The effect of the core-forming block structure on the morphology of block copolymer nanoparticles was investigated in detail.Transmission electron microscopy(TEM)analysis indicated that the brush-like core-forming block structure facilitated the formation of higher-order morphologies,while the branched core-forming block structure favored the formation of lower-order morphologies.Moreover,it was found that using macroCTAs with a shorter length also promoted the formation of higher-order morphologies.Finally,structures of block copolymers and the assemblies were further controlled by changing the structure of macro-CTA or using a binary mixture of two different macro-CTAs.We expect that this work not only sheds light on the synthesis of block copolymer nanoparticles but also provide important mechanistic insights into PISA of nonlinear block copolymers.
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.
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.
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.
基金funded by the National Key R&D Program of China(No.2022YFF0904000)Cross-disciplinary Innovation Project of Jilin University(No.JLUXKJC2021ZZ01)the financial support from National Natural Science Foundation of China(No.62201497).
文摘The performance of hydrogel radical polymerization under ambient conditions is a major challenge because oxygen is an effective radical quencher and the steps to remove or neutralize it are time consuming and laborious.A self-initiating system consisting of transition metals and acetylacetone has been successfully developed.The system is capable of initiating free radical polymerization of hydrogels at room temperature under aerobic conditions,which is attributed to carbon radicals generated by the oxidation of acetylacetone.Some of these carbon radicals reduce oxygen to generate hydroxyl radicals,which together induce self-coagulation of hydrogels.The polymerization system was effective for a variety of monomer and hydrogel swelling and shrinking schemes,and the reaction remained successful when exposed to saturated oxygen.In conclusion,the results demonstrate that the present strategy is an effective approach to addressing the challenge of deoxygenation in polymer synthesis,and provides a convenient method for synthesizing multifunctional hydrogels under ambient conditions.
基金financially supported by the joint lab of Shanghai Huayi 3F New Materials Co.,Ltd.Donghua University。
文摘Copolymers of fluoroethylene and vinyl ethers(FEVE)are soluble and curable at relatively low temperature,and are used as high-performance coatings and paints.Currently,most market-available FEVE products obtained through solution polymerization contain a large fraction of organic solvent,and hence,volatile organic compound(VOC)emissions cause environmental issues.In this study,the emulsion copolymerization of chlorotrifluoroethylene(CTFE)and vinyl ethers using an environmentally friendly emulsification system to produce waterborne FEVE was investigated.In addition to mixed nonionic and ionic surfactants,macromolecular monomer with double bond and polyoxyethylene segments were used in the emulsification system.The effect of adding macromolecular monomer and polyoxyethylene segment length of the nonionic surfactant on emulsion copolymerization were analyzed.An optimized emulsifier system for FEVE is proposed,and the prepared FEVE latexes exhibit excellent storage stability and film formation ability.
基金supported by the National Natural Science Foundation of China(No.22071166)the Priority Academic Program Development of Jiangsu High Education Institutions(PAPD).
文摘Exploration of new green polymerization strategies for the construction of conjugated polymers is important but challengeable.In this work,a multicomponent polymerization of acetylarenes,alkynones and ammonium acetate for in situ construction of conjugated poly(triarylpyridine)s was developed.The polymerization reactions of diacetylarenes,aromatic dialkynones and NH_(4)OAc were performed in dimethylsulfoxide(DMSO)under heating in the presence of potassium tert-butoxide(t-BuOK),affording four conjugated poly(2,4,6-triarylpyridine)s(PTAPs)in satisfactory yields.The resulting PTAPs have good solubility in common organic solvents and high thermal stability with 5%weight loss temperatures reaching up to 460℃.They are also electrochemically active.The PTAPs incorporating tetraphenylethene units manifest aggregation-induced emission features.Moreover,through simply being doped into poly(vinyl alcohol)(PVA)matrix,the polymer and model compound containing triphenylamine moieties exhibit room-temperature phosphorescence properties with ultralong lifetimes up to 696.2 ms and high quantum yields up to 28.7%.This work not only provides a facile green synthetic route for conjugated polymers but also offers new insights into the design of advanced materials with unique photophysical properties.
基金financially supported by the National Natural Science Foundation of China(No.52373011)。
文摘Living cationic polymerization of 4-acetoxystyrene(STO)was conducted in CH_(2)Cl_(2) at-15℃ using a dicumyl chloride(DCC)/SnCl_(4)/nBu_(4)NBr initiating system.Impurity moisture initiation was inhibited by adding proton trap 2,6-di-tert-butylpyridine(DTBP),and the controlled initiation of DCC was confirmed by ^(1)H nuclear magnetic resonance(^(1)H-NMR)spectroscopy and matrix-assisted laser desorption ionization time-offlight mass(MALDI-TOF-MS)spectrometry.The polymerization kinetics were analyzed to for optimizing the polymerization rate.Allyl-telechelic PSTOs(allyl-PSTO-allyl)with molecular weight(Mn)range of 3540–7800 g/mol and narrow molecular weight dispersity(Mw/Mn)about 1.25 were prepared through nucleophilic substitution with allyltrimethylsilane(ATMS)at approximately 40%monomer conversion.The experimental results indicate that the substitution efficiency of ATMS increased with higher ATMS concentration,temperature,and extended reaction time.Nearly unity ally-functionality for allyl-PSTO-allyl was achieved by adding sufficient SnCl_(4) prior to the substitution.
基金supported by Jiangsu Provincial Basic Research Program(Natural Science Foundation)Youth Fund(Grant No.BK20230885)International Joint Laboratory of Sustainable Manufacturing,Ministry of Education,Fundamental Research Funds for Central Universities(Grant No.NG2024012)+1 种基金Basic Research Project for Major Special Programs of Aero-Engine and Gas Turbine(Grant No.J2022-Ⅶ-0006-0048)High-Quality Development Special Project of the Ministry of Industry and Information Technology.
文摘As a key process in the manufacturing of hollow turbine blades for aeroengines,ceramic-core stereolithography(SL)is vital for the structural design and precise performance control of hollow turbine blades for aeroengines.Based on SL and digital light processing(DLP),ceramic SL has technical advantages such as high flexibility,short process flow,and integrated structure-performance manufacturing,making it ideal for manufacturing complex hollow ceramic cores.Currently,ceramic cores produced using this technology still encounter several challenges such as low bending strength,low dimensional accuracy,significant sintering shrinkage,and poor surface quality,which limit the innovative development and engineering applications of the additive manufacturing of UV-cured ceramics.This paper reviews the development of additive manufacturing technology and equipment for the vat polymerization of ceramic cores used in aeroengine blades and summarizes the principles and characteristics of vat polymerization for manufacturing ceramic cores.It also highlights research progress in lightweight structural design methods for ceramic cores,ceramic slurry preparation processes,SL processes,debinding and sintering processes,integration of forming system equipment,and verification of aeroengine blade casting.A comprehensive performance control strategy for the SL of ceramic cores is proposed,and future development directions and trends in ceramic-core fabrication using SL technology are discussed.
基金financially supported by the National Key R&D Program of China(No.2021YFA1501700)the National Natural Science Foundation of China(Nos.22371194 and 22301197)Fundamental Research Funds from Sichuan University(Nos.2023SCUNL103 and 2024SCUQJTX005)。
文摘Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.
基金the National Natural Science Foundation of China(52275294)the National Key Research and Development Program of China(2018YFA0703000).
文摘The designing and manufacturing of micro/nanoscale tools for delivery,diagnostic,and therapeutic are essential for their multiscale integration in the precision medicine field.Conventional three-dimensional(3D)printing approaches are not suitable for such kind of tools due to the accuracy limitation.Multiphoton polymerization(MPP)-based micro/nanomanufacturing is a noncontact,high-precision molding technology that has been widely used in the micro/nano field is a promising tool for micro/nanoscale related precision medicine.In this article the fundamentals of MPP-based technology and the required materials in precision medicine are overviewed.The biomedical applications in various scenarios are then summarized and categorized as delivery systems,microtissue modeling,surgery,and diagnosis.Finally,the existing challenges and future perspectives on MPP-based micro/nanomanufacturing for precision medicine are discussed,focusing on material design,process optimization,and practical applications to overcome its current limitations.
基金Supported by the National Natural Science Foundation of China(Nos.21773240 and 22173103)the University of the Chinese Academy of Sciences and Beijing National Laboratory for Molecular Sciences(No.BNLMS2023014)。
文摘Photoredox-mediated reversible-deactivation radical polymerization(RDRP)is an effective approach to synthesize polymers with defined composition and architecture.Current photoinduced RDRP primarily depends on outer-sphere electron transfer or homolysis mechanisms.Herein,we describe an example of iodine-mediated RDRP facilitated by photoinduced charge transfer complex(CTC)catalysis.The approach uses cheap and easily accessible N^(-)heterocyclic nitrenium salt(NHN^(+)...I^(-))as the photoactive CTC.Upon the irradiation of visible light,NHN^(+)...I^(-)undergoes single electron transfer to generate NHN·and I·radicals.The NHN·radical activates dormant Pn-I polymers via inner-sphere single electron transfer,leading to the propagating Pn·radical for chain growth and the I^(-)anion for recovering the CTC,and the I·radical deactivates the polymerization via coupling with Pn·.
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.
