Due to the structure characteristics of huge macromolecular size and the very low motion feature of the polymer chain which is very difficult to arrange regularly their long chain into the three dimensional space,thus...Due to the structure characteristics of huge macromolecular size and the very low motion feature of the polymer chain which is very difficult to arrange regularly their long chain into the three dimensional space,thus the polymer will incompletely crystallize except for the macroscopic single crystal of polydiacetylene polymerized by means of solid state crystalline polymerization.展开更多
Machine learning(ML),material genome,and big data approaches are highly overlapped in their strategies,algorithms,and models.They can target various definitions,distributions,and correlations of concerned physical par...Machine learning(ML),material genome,and big data approaches are highly overlapped in their strategies,algorithms,and models.They can target various definitions,distributions,and correlations of concerned physical parameters in given polymer systems,and have expanding applications as a new paradigm indispensable to conventional ones.Their inherent advantages in building quantitative multivariate correlations have largely enhanced the capability of scientific understanding and discoveries,thus facilitating mechanism exploration,target prediction,high-throughput screening,optimization,and rational and inverse designs.This article summarizes representative progress in the recent two decades focusing on the design,preparation,application,and sustainable development of polymer materials based on the exploration of key physical parameters in the composition-process-structure-property-performance relationship.The integration of both data-driven and physical insights through ML approaches to deepen fundamental understanding and discover novel polymer materials is categorically presented.Despite the construction and application of robust ML models,strategies and algorithms to deal with variant tasks in polymer science are still in rapid growth.The challenges and prospects are then presented.We believe that the innovation in polymer materials will thrive along the development of ML approaches,from efficient design to sustainable applications.展开更多
Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynam...Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynamic size and slower degradation.It is key to develop facile methods to large-scale synthesis of polymer rings with tunable compositions and microstructures.Recent progresses in large-scale synthesis of polymer rings against single-chain dynamic nanoparticles,and the example applications in synchronous enhancing toughness and strength of polymer nanocomposites are summarized.Once there is the breakthrough in rational design and effective large-scale synthesis of polymer rings and their functional derivatives,a family of cyclic functional hybrids would be available,thus providing a new paradigm in developing polymer science and engineering.展开更多
Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving...Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.展开更多
Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundame...Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundamental understanding on how they control the electrochemical performances.Herein,by harnessing the electrostatic adsorption of one-dimensional nanofiller(i.e.,surface-charged halloysite nanotubes,d-HNTs),we successfully fabricate a high-performance polymer nanocomposite electrolyte enabled by strong surface adsorption,referred as adsorption-state polymer electrolyte(ASPE).This ASPE shows fast ion transport(0.71±0.05 mS cm^(-1)at room temperature),high mechanical strength and toughness(10.3±0.05 MPa;15.73 MJ m^(-3)),improved lithium-ion transference number,and long cycle life with lithium metal anode,in comparison with the sample without the d-HNT adsorption effect.To fundamentally understand these high performances,an anion-rich asymmetric solvent structure model is further proposed and evidenced by both experiments and simulation studies.Results show that the electrostatic adsorption among the d-HNT,ionic liquid electrolyte,and polymer chain generates a nano filler-supported fast ion-conduction pathway with asymmetric Li+-coordination microenvironment.Meanwhile,the anion-rich asymmetric solvent structure model of ASPE also generates a fast de-solvation and anion-derived stable solid-electrolyte interphase for lithium metal anode.The high performance and understanding of the mechanism for ASPE provide a promising path to develop advanced polymer electrolytes.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
Advancing the integration of artificial intelligence and polymer science requires high-quality,open-source,and large-scale datasets.However,existing polymer databases often suffer from data sparsity,lack of polymer-pr...Advancing the integration of artificial intelligence and polymer science requires high-quality,open-source,and large-scale datasets.However,existing polymer databases often suffer from data sparsity,lack of polymer-property labels,and limited accessibility,hindering system-atic modeling across property prediction tasks.Here,we present OpenPoly,a curated experimental polymer database derived from extensive lit-erature mining and manual validation,comprising 3985 unique polymer-property data points spanning 26 key properties.We further develop a multi-task benchmarking framework that evaluates property prediction using four encoding methods and eight representative models.Our re-sults highlight that the optimized degree-of-polymerization encoding coupled with Morgan fingerprints achieves an optimal trade-off between computational cost and accuracy.In data-scarce condition,XGBoost outperforms deep learning models on key properties such as dielectric con-stant,glass transition temperature,melting point,and mechanical strength,achieving R2 scores of 0.65-0.87.To further showcase the practical utility of the database,we propose potential polymers for two energy-relevant applications:high temperature polymer dielectrics and fuel cell membranes.By offering a consistent and accessible benchmark and database,OpenPoly paves the way for more accurate polymer-property modeling and fosters data-driven advances in polymer genome engineering.展开更多
The self-assembly of block copolymers serves as an effective approach for fabricating various periodic ordered nanostructures. By employing self-consistent field theory (SCFT) to calculate the phase diagrams of block ...The self-assembly of block copolymers serves as an effective approach for fabricating various periodic ordered nanostructures. By employing self-consistent field theory (SCFT) to calculate the phase diagrams of block copolymers, one can accurately predict their self-assembly behaviors, thus providing guidance for the fabrication of various novel structures. However, SCFT is highly sensitive to initial conditions because it finds the free energy minima through an iterative process. Consequently, constructing phase diagrams using SCFT typically requires predefined candidate structures based on the experience of researchers. Such experience-dependent strategies often miss some structures and thus result in inaccurate phase diagrams. Recently, artificial intelligence (AI) techniques have demonstrated significant potential across diverse fields of science and technology. By leveraging AI methods, it is possible to reduce reliance on human experience, thereby constructing more robust and reliable phase diagrams. In this work, we demonstrate how to combine AI with SCFT to automatically search for self-assembled structures of block copolymers and construct phase diagrams. Our aim is to realize automatic construction of block copolymer phase diagrams while minimizing reliance on human prior knowledge.展开更多
The facile synthesis of high-valued polymers from waste molecules or low-cost common chemicals presents a significant challenge.Here,we develop a series of degradable poly(thiocarbonate)s from the new step-growth poly...The facile synthesis of high-valued polymers from waste molecules or low-cost common chemicals presents a significant challenge.Here,we develop a series of degradable poly(thiocarbonate)s from the new step-growth polymerization of diols,carbonyl sulfide(CoS,or carbon disulfide,CS_(2)),and dichlorides.Diols and dichlorides are common chemicals,and CoS(CS_(2))is released as industrial waste.In addition to abun-dant feedstocks,the method is efficient and performed under mild conditions,using common organic bases as catalysts,and affording unprece-dented polymers.When cos,diols,and dihalides were used as monomers,optimized conditions could completely suppress the oxygen-sulfur exchange reaction,enabling the efficient synthesis of well-defined poly(monothiocarbonate)s with melting points ranging from 48°C to 101°C.These polymers,which have a structure similar to polyethylene with low-density in-chain polar groups,exhibit remarkable toughness and ductili-ty that rival those of high-density polyethylene(melting point:90°C,tensile strength:21.6±0.7 MPa,and elongation at break:576%).Moreover,the obtained poly(monothiocarbonate)s can be chemically degraded by alcoholysis to yield small-molecule diols and dithiols.When CS_(2)was used in place of cos,a pronounced oxygen-sulfur exchange reaction occurred.By optimizing reaction condition,it was found that polymers with-S(C=O)S-and-S(C=S)S-as the main repeating units exhibited high thermal stability and crystallinity.Thus,a new approach for regulat-ing the structure of polythiocarbonates via the oxygen-sulfur exchange reaction is developed.Overall,the polymers hold great potential for green materials due to their facile synthesis,readily available feedstocks,excellent performance,and chemical degradability.展开更多
Colloidal molecules exhibit unique electronic,optical,and magnetic properties owing to their molecular-like configurations and coupling effects,making them promising building blocks for multifunctional materials.Howev...Colloidal molecules exhibit unique electronic,optical,and magnetic properties owing to their molecular-like configurations and coupling effects,making them promising building blocks for multifunctional materials.However,achieving precise and controllable assembly of isotropic nanoparticles with high yields remains a great challenge.In this study,we present a synergistic strategy that integrates molecular dynamics simulations with interpretable machine learning to develop a programmable assembly system based on block copolymers and DNA-functionalized nanoparticles.Our simulation results reveal that block copolymer modification facilitates stepwise control over surface phase separation and nanoparticle coassembly,thereby enhancing structural stability and efficiently suppressing disordered aggregation of atom-like nanoparticles.Furthermore,we demonstrated that precise,controllable,and programmable assembly of colloidal molecules can be achieved through rational DNA sequence design.SHapley Additive exPlanations(SHAP)analysis identified key structural descriptors that govern assembly outcomes and elucidated their underlying mechanistic roles.This work not only deepens the understanding of colloidal molecule assembly mechanisms but also lays a theoretical foundation for the rational design of functional colloidal architectures in nanomaterial science.展开更多
Shear banding in entangled polymer melts remains a fundamental yet unresolved phenomenon in nonlinear polymer rheology.Here,we perform molecular dynamics simulations of bidisperse entangled melts—comprising equal num...Shear banding in entangled polymer melts remains a fundamental yet unresolved phenomenon in nonlinear polymer rheology.Here,we perform molecular dynamics simulations of bidisperse entangled melts—comprising equal numbers of chains with lengths N=200 and N=400—to uncover the structural origins and dynamic evolution of shear banding.This bidisperse system amplifies spatial heterogeneities in the entanglement network and facilitates direct comparison with monodisperse melts of N=300,revealing quantitatively consistent steady-state shear stress versus shear rate responses.Notably,a pronounced stress plateau spanning over an order of magnitude in shear rate is observed,within which shear banding emerges reproducibly across independent simulations,as confirmed by systematic velocity profile and interface position analyses.Our findings challenge the prevailing notion that shear banding arises solely from dynamic flow instabilities.Instead,we establish a microstructure-driven framework,demonstrating that shear band nucleation is governed by pre-existing structural heterogeneities—specifically,localized weakening of the entanglement network at short-chain-enriched“soft spots”,indicative of a robust microstructural memory effect.During shear start-up,short chains preferentially disentangle and migrate along the shear direction;beyond a critical strain,long chains retract and redistribute away from the fast shear band center to minimize elastic energy.This chain-length-dependent migration dynamically enriches the shear band in short chains,stabilizing its structure and revealing a molecular mechanism that links entanglement heterogeneity to macroscopic flow localization.By bridging molecular-scale structural features with nonlinear rheological responses,this work offers a complementary perspective to classical tube and convective constraint release(CCR)models,highlighting the critical interplay between microstructural heterogeneity and chain migration in the onset and persistence of shear banding.展开更多
Flexible and stretchable energy storage devices are highly desirable for wearable electronics,particularly in the emerging fields of smart clothes,medical instruments,and stretchable skin.Lithium metal batteries(LMBs)...Flexible and stretchable energy storage devices are highly desirable for wearable electronics,particularly in the emerging fields of smart clothes,medical instruments,and stretchable skin.Lithium metal batteries(LMBs) with high power density and long cycle life are one of the ideal power sources for flexible and stretchable energy storage devices.However,the current LMBs are usually too rigid and bulky to meet the requirements of these devices.The electrolyte is the critical component that determines the energy density and security of flexible and stretchable LMBs.Among various electrolytes,gel polymer electrolytes(GPEs) perform excellent flexibility,safety,and high ionic conductivity compared with traditional liquid electrolytes and solid electrolytes,fulfilling the next generation deformable LMBs.This essay mainly reviews and highlights the recent progress in GPEs for flexible/stretchable LMBs and provides some useful insights for people interested in this field.Additionally,the multifunctional GPEs with self-healing,flame retardant,and temperature tolerance abilities are summarized.Finally,the perspectives and opportunities for flexible and stretchable GPEs are discussed.展开更多
Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving t...Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.展开更多
High catalytic efficiencies in ring opening polymerization(ROP)of a large ring-sized macrolactone,ω-pentadecalactone(PDL),by using transition metal Fe(II)-based catalysts were achieved for the first time in this stud...High catalytic efficiencies in ring opening polymerization(ROP)of a large ring-sized macrolactone,ω-pentadecalactone(PDL),by using transition metal Fe(II)-based catalysts were achieved for the first time in this study.Benefited from the bulky nature of the ligatedα-diimine ligands,as evidenced from single-crystal structures,as well as the weakly oxophilic nature of the metal centers,chain transesterification reactions could be partially suppressed,allowing the polymerization proceed in a living-like and semi-controllable manner,i.e.good linear dependence of propagation rates on catalyst concentration and PDL concentration as observed in the detailed kinetics studies.The whole polymerization proceeds via a“coordination-insertion”mechanism,and with the aid of density functional theory(DFT)calculation studies,a“slow insertion→fast elimination”manner was demonstrated for the monomer propagation step,suggesting the insertion of Fe-OR into the carbonyl group C=O as the rate-determining step.The present catalytic system also showed fast chain transfer reactions to alcohol compounds,affording quasi-immortal characteristics.DFT calculations showed that such a transfer reaction only required an energy barrier of 6.4 kcal/mol,performing a good consistency with the fast chain transfer rates.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
Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By us...Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By using dynamic light scattering(DLS),we discovered a dynamical transition for charged ring polymers with increasing ring concentration in the gel matrix from a diffusive state to a non-diffusive topological frustrated state with a more compact conformation.When the ring polymer size is smaller than the mesh size of the gel matrix,the rings are diffusive at low concentration of 5 g/L.The ring diffusion coefficient in the gel matrix is an order of magnitude smaller than that of rings in solution,obeying the Ogston's model.At high ring concentration of 40 g/L,the collective dynamical behavior of the charged rings exhibits a topologically frustrated non-diffusive state,which may originate from the inter-ring threading with the external confinement from the gel matrix.Based on our previous theoretical work,we also conjectured that in such a non-diffusive state,the ring polymers might adopt a more compact conformation with the overall size exponentν=1/3.展开更多
Polymers often exhibit multi-state conformational transitions with multiple pathways as temperature varies.However,characterizing the inherent features of these pathways is hindered by the lack of physical characteriz...Polymers often exhibit multi-state conformational transitions with multiple pathways as temperature varies.However,characterizing the inherent features of these pathways is hindered by the lack of physical characterizations that can distinguish various transition pathways between complex and disordered states.In this work,we introduced a machine-learning framework based on spatiotemporal point-cloud neural networks to identify and analyze conformational transition pathways in polymer chains.As a case study,we applied this framework to the temperature-induced unfolding of a single semi-flexible polymer chain,simulated via coarse-grained molecular dynamics.We first combined spatiotemporal point cloud neural networks and contrastive learning to extract features of conformational evolution,and then we employed unsupervised learning methods to cluster distinct transition pathways and unfolding trajectories.Our results reveal that,with increasing temperature,semi-flexible polymer chains exhibit five distinct unfolding pathways:rigid rod→random coil;small toroid→large toroid→hairpin→random coil;rod bundle→hairpin→random coil;hairpin→random coil;and tailed structure→random coil.We further calculated the structural order parameters of those typical conformations with distinct transition pathways,we distincted five transition mechanisms,including the straightening of rigid rods,tightening of small rings,expansion of hairpin ends,symmetrization of rod bundles,and retraction of tailed structures.These findings demonstrate that our framework presents a promising data-driven approach for analyzing complex conformational transitions in disordered polymers,which might be potentially extendable to other heterogeneous systems like intrinsically disordered proteins.展开更多
Given the increasing demand for distributed electricity,there is a burning desire to harvest electricity from renewable sources using environmentally friendly methods.Thermoelectric (TE) materials can meet this requir...Given the increasing demand for distributed electricity,there is a burning desire to harvest electricity from renewable sources using environmentally friendly methods.Thermoelectric (TE) materials can meet this requirement not only because of their ability to convert heat directly into electricity,enabling energy harvesting from waste heat and natural heat resources,but also because more than 60%of the energy is lost as waste heat [1].The discovery of the TE effect dates back to the 1820s when T.M.Seebeck observed electricity generation at the junction of two conductors with different temperatures.Additionally,when a voltage is applied to TE materials,they can create a temperature difference to enable solid-state cooling (known as the Peltier effect).Therefore,the TE effect promises both sustainable energy solutions and temperature control technologies.Over the past two decades,the urgent demand for powering ubiquitous Internet of Things devices has sparked significant interest in flexible thermoelectrics(F-TEs),which raises an intriguing question:Is the intrinsically flexible polymer an important candidate for state-of-the-art F-TEs applications?展开更多
The crystallization behavior of polymers is significantly influenced by molecular chain length and the dispersion of varying chain lengths.The complexity of studying crystallization arises from the dispersity of polym...The crystallization behavior of polymers is significantly influenced by molecular chain length and the dispersion of varying chain lengths.The complexity of studying crystallization arises from the dispersity of polymer materials and the typically slow cooling rates.Recent advancements in fast cooling techniques have rendered the investigation of polymer crystallization at varying cooling rates an attractive area of research;however,a systematic quantitative framework for this process is still lacking.We employ a coarse-grained model for polyvinyl alcohol(CGPVA)in molecular dynamics simulations to study the crystallization of linear polymers with varying chain lengths under variable cooling rates.Monodisperse,bidisperse and polydisperse samples are simulated.We propose two formulae based on a two-phase assumption to fit the exothermal curves obtained during cooling.Based on these formulae,better estimations of crystallization temperatures are obtained and the effects of chain lengths and cooling rates are studied.It is found that the crystallization temperature increases with chain length,similar to the Gibbs-Thomson relation formelting temperature,indicating a strong relation between fast crystallization and glass formation in linear polymers.Extrapolation to the infinitely slow cooling rate provides an easy way in simulations to estimate the equilibrium crystallization temperature.The effective chain lengths of polydisperse and bidisperse samples are found to be the number-averaged chain lengths compared to the weight-averaged ones.The chain length-dependent crystallization exhibits crossover behavior near the entanglement length,indicating the effects of entanglements under fast cooling conditions.The effect of chain length dispersity on crystallization becomes more obvious under fast cooling conditions.展开更多
Recently circularly polarized luminescence(CPL)materials have attracted significant interest.Introducing reversible dynamic property to these materials has been a key focus in cutting-edge fields,such as in high-level...Recently circularly polarized luminescence(CPL)materials have attracted significant interest.Introducing reversible dynamic property to these materials has been a key focus in cutting-edge fields,such as in high-level information encryption.Here,we provided a novel and general strategy involving handednessselective filtration and ground-state chiral self-recovery(CSR)in double film system to address this issue.Based on this strategy,we achieved CPL switch through the reversible modulation of ground-state chirality including absorption and scattering circular dichroism(CD)signals over the full UV-visible wavelength range(365-700 nm)in a single azobenzene polymer(PAzo)film.More importantly,by flexibly changing the type of fluorescent films,it is convenient to achieve general excited-state CSR,that is reversible switching of full-color including ideal white(CIE coordinate(0.33,0.33)),as well as room-temperature phosphorescent CPL.All these CPL signals without almost any intensity decay after three cycles of onand-off switching.Experimental results indicated that the trans-cis isomerization and ordered rearrangement of azobenzene units in PAzo film were the fundamental reasons for realizing CPL switching.Finally,based on this system we achieved dynamic visual encryption and decryption process including multiple decryption methods.This study provides an effective method for constructing a universally applicable chiroptical switch in excited state.展开更多
文摘Due to the structure characteristics of huge macromolecular size and the very low motion feature of the polymer chain which is very difficult to arrange regularly their long chain into the three dimensional space,thus the polymer will incompletely crystallize except for the macroscopic single crystal of polydiacetylene polymerized by means of solid state crystalline polymerization.
基金supported by the National Natural Science Foundation of China(Nos.22173094,52303121,and 52293471)National Key Research and Development Program of China(Nos.2022YFB3707303 and 2021YFB3801500)+2 种基金Major Science and Technology Projects for Independent Innovation of China FAW Group Co.Ltd.(No.20220301018GX)Guizhou Provincial Basic Research Program(Nos.BQW[2024]006 and Z2024021)Guizhou University Talents Fund(No.C0048072).
文摘Machine learning(ML),material genome,and big data approaches are highly overlapped in their strategies,algorithms,and models.They can target various definitions,distributions,and correlations of concerned physical parameters in given polymer systems,and have expanding applications as a new paradigm indispensable to conventional ones.Their inherent advantages in building quantitative multivariate correlations have largely enhanced the capability of scientific understanding and discoveries,thus facilitating mechanism exploration,target prediction,high-throughput screening,optimization,and rational and inverse designs.This article summarizes representative progress in the recent two decades focusing on the design,preparation,application,and sustainable development of polymer materials based on the exploration of key physical parameters in the composition-process-structure-property-performance relationship.The integration of both data-driven and physical insights through ML approaches to deepen fundamental understanding and discover novel polymer materials is categorically presented.Despite the construction and application of robust ML models,strategies and algorithms to deal with variant tasks in polymer science are still in rapid growth.The challenges and prospects are then presented.We believe that the innovation in polymer materials will thrive along the development of ML approaches,from efficient design to sustainable applications.
基金Supported by the National Natural Science Foundation of China(Nos.52293472,22473096 and 22471164)。
文摘Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynamic size and slower degradation.It is key to develop facile methods to large-scale synthesis of polymer rings with tunable compositions and microstructures.Recent progresses in large-scale synthesis of polymer rings against single-chain dynamic nanoparticles,and the example applications in synchronous enhancing toughness and strength of polymer nanocomposites are summarized.Once there is the breakthrough in rational design and effective large-scale synthesis of polymer rings and their functional derivatives,a family of cyclic functional hybrids would be available,thus providing a new paradigm in developing polymer science and engineering.
基金the financial support from the National Natural Science Foundation of China(52203123 and 52473248)State Key Laboratory of Polymer Materials Engineering(sklpme2024-2-04)+1 种基金the Fundamental Research Funds for the Central Universitiessponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.
基金financial support from the National Natural Science Foundation of China(52203123)the Sichuan Science and Technology Program(2023NSFSC0991)+2 种基金the State Key Laboratory of Polymer Materials Engineering(sklpme 2023-1-05 and sklpme 2024-2-04)the Fundamental Research Funds for the Central Universitiespartially sponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundamental understanding on how they control the electrochemical performances.Herein,by harnessing the electrostatic adsorption of one-dimensional nanofiller(i.e.,surface-charged halloysite nanotubes,d-HNTs),we successfully fabricate a high-performance polymer nanocomposite electrolyte enabled by strong surface adsorption,referred as adsorption-state polymer electrolyte(ASPE).This ASPE shows fast ion transport(0.71±0.05 mS cm^(-1)at room temperature),high mechanical strength and toughness(10.3±0.05 MPa;15.73 MJ m^(-3)),improved lithium-ion transference number,and long cycle life with lithium metal anode,in comparison with the sample without the d-HNT adsorption effect.To fundamentally understand these high performances,an anion-rich asymmetric solvent structure model is further proposed and evidenced by both experiments and simulation studies.Results show that the electrostatic adsorption among the d-HNT,ionic liquid electrolyte,and polymer chain generates a nano filler-supported fast ion-conduction pathway with asymmetric Li+-coordination microenvironment.Meanwhile,the anion-rich asymmetric solvent structure model of ASPE also generates a fast de-solvation and anion-derived stable solid-electrolyte interphase for lithium metal anode.The high performance and understanding of the mechanism for ASPE provide a promising path to develop advanced polymer electrolytes.
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 Natural Science Foundation of China (Nos. 92372126,52373203)the Excellent Young Scientists Fund Program
文摘Advancing the integration of artificial intelligence and polymer science requires high-quality,open-source,and large-scale datasets.However,existing polymer databases often suffer from data sparsity,lack of polymer-property labels,and limited accessibility,hindering system-atic modeling across property prediction tasks.Here,we present OpenPoly,a curated experimental polymer database derived from extensive lit-erature mining and manual validation,comprising 3985 unique polymer-property data points spanning 26 key properties.We further develop a multi-task benchmarking framework that evaluates property prediction using four encoding methods and eight representative models.Our re-sults highlight that the optimized degree-of-polymerization encoding coupled with Morgan fingerprints achieves an optimal trade-off between computational cost and accuracy.In data-scarce condition,XGBoost outperforms deep learning models on key properties such as dielectric con-stant,glass transition temperature,melting point,and mechanical strength,achieving R2 scores of 0.65-0.87.To further showcase the practical utility of the database,we propose potential polymers for two energy-relevant applications:high temperature polymer dielectrics and fuel cell membranes.By offering a consistent and accessible benchmark and database,OpenPoly paves the way for more accurate polymer-property modeling and fosters data-driven advances in polymer genome engineering.
基金supported by the National Natural Science Foundation of China(Nos.52394272,22333002,22203018,22303017).
文摘The self-assembly of block copolymers serves as an effective approach for fabricating various periodic ordered nanostructures. By employing self-consistent field theory (SCFT) to calculate the phase diagrams of block copolymers, one can accurately predict their self-assembly behaviors, thus providing guidance for the fabrication of various novel structures. However, SCFT is highly sensitive to initial conditions because it finds the free energy minima through an iterative process. Consequently, constructing phase diagrams using SCFT typically requires predefined candidate structures based on the experience of researchers. Such experience-dependent strategies often miss some structures and thus result in inaccurate phase diagrams. Recently, artificial intelligence (AI) techniques have demonstrated significant potential across diverse fields of science and technology. By leveraging AI methods, it is possible to reduce reliance on human experience, thereby constructing more robust and reliable phase diagrams. In this work, we demonstrate how to combine AI with SCFT to automatically search for self-assembled structures of block copolymers and construct phase diagrams. Our aim is to realize automatic construction of block copolymer phase diagrams while minimizing reliance on human prior knowledge.
基金supported by the National Natural Science Foundation of China(Nos.223B2119,U23A2083,52373014,52203129).
文摘The facile synthesis of high-valued polymers from waste molecules or low-cost common chemicals presents a significant challenge.Here,we develop a series of degradable poly(thiocarbonate)s from the new step-growth polymerization of diols,carbonyl sulfide(CoS,or carbon disulfide,CS_(2)),and dichlorides.Diols and dichlorides are common chemicals,and CoS(CS_(2))is released as industrial waste.In addition to abun-dant feedstocks,the method is efficient and performed under mild conditions,using common organic bases as catalysts,and affording unprece-dented polymers.When cos,diols,and dihalides were used as monomers,optimized conditions could completely suppress the oxygen-sulfur exchange reaction,enabling the efficient synthesis of well-defined poly(monothiocarbonate)s with melting points ranging from 48°C to 101°C.These polymers,which have a structure similar to polyethylene with low-density in-chain polar groups,exhibit remarkable toughness and ductili-ty that rival those of high-density polyethylene(melting point:90°C,tensile strength:21.6±0.7 MPa,and elongation at break:576%).Moreover,the obtained poly(monothiocarbonate)s can be chemically degraded by alcoholysis to yield small-molecule diols and dithiols.When CS_(2)was used in place of cos,a pronounced oxygen-sulfur exchange reaction occurred.By optimizing reaction condition,it was found that polymers with-S(C=O)S-and-S(C=S)S-as the main repeating units exhibited high thermal stability and crystallinity.Thus,a new approach for regulat-ing the structure of polythiocarbonates via the oxygen-sulfur exchange reaction is developed.Overall,the polymers hold great potential for green materials due to their facile synthesis,readily available feedstocks,excellent performance,and chemical degradability.
基金financially supported by the National Natural Science Foundation of China(Nos.92477118 and 22173045)the Postgraduate Research and Practice Innovation Program of Jiangsu Province(No.KYCX25_0188)。
文摘Colloidal molecules exhibit unique electronic,optical,and magnetic properties owing to their molecular-like configurations and coupling effects,making them promising building blocks for multifunctional materials.However,achieving precise and controllable assembly of isotropic nanoparticles with high yields remains a great challenge.In this study,we present a synergistic strategy that integrates molecular dynamics simulations with interpretable machine learning to develop a programmable assembly system based on block copolymers and DNA-functionalized nanoparticles.Our simulation results reveal that block copolymer modification facilitates stepwise control over surface phase separation and nanoparticle coassembly,thereby enhancing structural stability and efficiently suppressing disordered aggregation of atom-like nanoparticles.Furthermore,we demonstrated that precise,controllable,and programmable assembly of colloidal molecules can be achieved through rational DNA sequence design.SHapley Additive exPlanations(SHAP)analysis identified key structural descriptors that govern assembly outcomes and elucidated their underlying mechanistic roles.This work not only deepens the understanding of colloidal molecule assembly mechanisms but also lays a theoretical foundation for the rational design of functional colloidal architectures in nanomaterial science.
基金financially supported by the National Natural Science Foundation of China(Nos.22341304,22341303 and 22103079)National Key R&D Program of China(Nos.2020YFA0713601 and 2023YFA1008800)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDC0180303)Fundamental Enhancement Program(No.2024-JCJQ-JJ-0247)。
文摘Shear banding in entangled polymer melts remains a fundamental yet unresolved phenomenon in nonlinear polymer rheology.Here,we perform molecular dynamics simulations of bidisperse entangled melts—comprising equal numbers of chains with lengths N=200 and N=400—to uncover the structural origins and dynamic evolution of shear banding.This bidisperse system amplifies spatial heterogeneities in the entanglement network and facilitates direct comparison with monodisperse melts of N=300,revealing quantitatively consistent steady-state shear stress versus shear rate responses.Notably,a pronounced stress plateau spanning over an order of magnitude in shear rate is observed,within which shear banding emerges reproducibly across independent simulations,as confirmed by systematic velocity profile and interface position analyses.Our findings challenge the prevailing notion that shear banding arises solely from dynamic flow instabilities.Instead,we establish a microstructure-driven framework,demonstrating that shear band nucleation is governed by pre-existing structural heterogeneities—specifically,localized weakening of the entanglement network at short-chain-enriched“soft spots”,indicative of a robust microstructural memory effect.During shear start-up,short chains preferentially disentangle and migrate along the shear direction;beyond a critical strain,long chains retract and redistribute away from the fast shear band center to minimize elastic energy.This chain-length-dependent migration dynamically enriches the shear band in short chains,stabilizing its structure and revealing a molecular mechanism that links entanglement heterogeneity to macroscopic flow localization.By bridging molecular-scale structural features with nonlinear rheological responses,this work offers a complementary perspective to classical tube and convective constraint release(CCR)models,highlighting the critical interplay between microstructural heterogeneity and chain migration in the onset and persistence of shear banding.
基金financial support from National Natural Science Foundation of China(Nos.22005186 and 51877132) was acknowledged。
文摘Flexible and stretchable energy storage devices are highly desirable for wearable electronics,particularly in the emerging fields of smart clothes,medical instruments,and stretchable skin.Lithium metal batteries(LMBs) with high power density and long cycle life are one of the ideal power sources for flexible and stretchable energy storage devices.However,the current LMBs are usually too rigid and bulky to meet the requirements of these devices.The electrolyte is the critical component that determines the energy density and security of flexible and stretchable LMBs.Among various electrolytes,gel polymer electrolytes(GPEs) perform excellent flexibility,safety,and high ionic conductivity compared with traditional liquid electrolytes and solid electrolytes,fulfilling the next generation deformable LMBs.This essay mainly reviews and highlights the recent progress in GPEs for flexible/stretchable LMBs and provides some useful insights for people interested in this field.Additionally,the multifunctional GPEs with self-healing,flame retardant,and temperature tolerance abilities are summarized.Finally,the perspectives and opportunities for flexible and stretchable GPEs are discussed.
基金supported by the National Natural Science Foundation of China(No.U23B6011)the Jilin Provincial Science and Technology Department Program(No.20230101347JC)。
文摘Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.
基金financially supported by the National Natural Science Foundation of China(Nos.21901020 and 22003076)China Postdoctoral Science Foundation(No.2021M701818)+1 种基金Shandong Provincial Natural Science Foundation(No.ZR2022QE237)the Qingdao Postdoctoral Applied Research Project.H.Liu sincerely acknowledges financial support from the Taishan Scholars Program(No.tsqn202211165)。
文摘High catalytic efficiencies in ring opening polymerization(ROP)of a large ring-sized macrolactone,ω-pentadecalactone(PDL),by using transition metal Fe(II)-based catalysts were achieved for the first time in this study.Benefited from the bulky nature of the ligatedα-diimine ligands,as evidenced from single-crystal structures,as well as the weakly oxophilic nature of the metal centers,chain transesterification reactions could be partially suppressed,allowing the polymerization proceed in a living-like and semi-controllable manner,i.e.good linear dependence of propagation rates on catalyst concentration and PDL concentration as observed in the detailed kinetics studies.The whole polymerization proceeds via a“coordination-insertion”mechanism,and with the aid of density functional theory(DFT)calculation studies,a“slow insertion→fast elimination”manner was demonstrated for the monomer propagation step,suggesting the insertion of Fe-OR into the carbonyl group C=O as the rate-determining step.The present catalytic system also showed fast chain transfer reactions to alcohol compounds,affording quasi-immortal characteristics.DFT calculations showed that such a transfer reaction only required an energy barrier of 6.4 kcal/mol,performing a good consistency with the fast chain transfer rates.
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supported by the National Natural Science Foundation of China(No.22273114)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0770101)+1 种基金the National Key R&D Program of China(No.2023YFE0124500),the National Key R&D Program of China(No.2023YFC2411203)International Partnership Program of the Chinese Academy of Sciences(No.027GJHZ2022061FN)。
文摘Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By using dynamic light scattering(DLS),we discovered a dynamical transition for charged ring polymers with increasing ring concentration in the gel matrix from a diffusive state to a non-diffusive topological frustrated state with a more compact conformation.When the ring polymer size is smaller than the mesh size of the gel matrix,the rings are diffusive at low concentration of 5 g/L.The ring diffusion coefficient in the gel matrix is an order of magnitude smaller than that of rings in solution,obeying the Ogston's model.At high ring concentration of 40 g/L,the collective dynamical behavior of the charged rings exhibits a topologically frustrated non-diffusive state,which may originate from the inter-ring threading with the external confinement from the gel matrix.Based on our previous theoretical work,we also conjectured that in such a non-diffusive state,the ring polymers might adopt a more compact conformation with the overall size exponentν=1/3.
基金financially supported by the National Key R&D Program of China(No.2022YFB3707303)the National Natural Science Foundation of China(No.52293471)。
文摘Polymers often exhibit multi-state conformational transitions with multiple pathways as temperature varies.However,characterizing the inherent features of these pathways is hindered by the lack of physical characterizations that can distinguish various transition pathways between complex and disordered states.In this work,we introduced a machine-learning framework based on spatiotemporal point-cloud neural networks to identify and analyze conformational transition pathways in polymer chains.As a case study,we applied this framework to the temperature-induced unfolding of a single semi-flexible polymer chain,simulated via coarse-grained molecular dynamics.We first combined spatiotemporal point cloud neural networks and contrastive learning to extract features of conformational evolution,and then we employed unsupervised learning methods to cluster distinct transition pathways and unfolding trajectories.Our results reveal that,with increasing temperature,semi-flexible polymer chains exhibit five distinct unfolding pathways:rigid rod→random coil;small toroid→large toroid→hairpin→random coil;rod bundle→hairpin→random coil;hairpin→random coil;and tailed structure→random coil.We further calculated the structural order parameters of those typical conformations with distinct transition pathways,we distincted five transition mechanisms,including the straightening of rigid rods,tightening of small rings,expansion of hairpin ends,symmetrization of rod bundles,and retraction of tailed structures.These findings demonstrate that our framework presents a promising data-driven approach for analyzing complex conformational transitions in disordered polymers,which might be potentially extendable to other heterogeneous systems like intrinsically disordered proteins.
文摘Given the increasing demand for distributed electricity,there is a burning desire to harvest electricity from renewable sources using environmentally friendly methods.Thermoelectric (TE) materials can meet this requirement not only because of their ability to convert heat directly into electricity,enabling energy harvesting from waste heat and natural heat resources,but also because more than 60%of the energy is lost as waste heat [1].The discovery of the TE effect dates back to the 1820s when T.M.Seebeck observed electricity generation at the junction of two conductors with different temperatures.Additionally,when a voltage is applied to TE materials,they can create a temperature difference to enable solid-state cooling (known as the Peltier effect).Therefore,the TE effect promises both sustainable energy solutions and temperature control technologies.Over the past two decades,the urgent demand for powering ubiquitous Internet of Things devices has sparked significant interest in flexible thermoelectrics(F-TEs),which raises an intriguing question:Is the intrinsically flexible polymer an important candidate for state-of-the-art F-TEs applications?
基金National Natural Science Foundation of China No.22341302.
文摘The crystallization behavior of polymers is significantly influenced by molecular chain length and the dispersion of varying chain lengths.The complexity of studying crystallization arises from the dispersity of polymer materials and the typically slow cooling rates.Recent advancements in fast cooling techniques have rendered the investigation of polymer crystallization at varying cooling rates an attractive area of research;however,a systematic quantitative framework for this process is still lacking.We employ a coarse-grained model for polyvinyl alcohol(CGPVA)in molecular dynamics simulations to study the crystallization of linear polymers with varying chain lengths under variable cooling rates.Monodisperse,bidisperse and polydisperse samples are simulated.We propose two formulae based on a two-phase assumption to fit the exothermal curves obtained during cooling.Based on these formulae,better estimations of crystallization temperatures are obtained and the effects of chain lengths and cooling rates are studied.It is found that the crystallization temperature increases with chain length,similar to the Gibbs-Thomson relation formelting temperature,indicating a strong relation between fast crystallization and glass formation in linear polymers.Extrapolation to the infinitely slow cooling rate provides an easy way in simulations to estimate the equilibrium crystallization temperature.The effective chain lengths of polydisperse and bidisperse samples are found to be the number-averaged chain lengths compared to the weight-averaged ones.The chain length-dependent crystallization exhibits crossover behavior near the entanglement length,indicating the effects of entanglements under fast cooling conditions.The effect of chain length dispersity on crystallization becomes more obvious under fast cooling conditions.
基金the financial support from the National Natural Science Foundation of China(Nos.22301206,92356305 and 22301208)Natural Science Foundation of Anhui Province(No.2308085J15)+5 种基金Natural Science Foundation of Anhui Provincial Higher Education Institutions(No.2023AH010012)China Post-doctoral Science Foundation(No.2022M722312)the Key Laboratory of Polymeric Material Design and Synthesis for Biomedical Functionthe Priority Academic Program Development(PAPD)of Jiangsu Higher Education InstitutionsJiangsu Funding Program for Excellent Postdoctoral Talentthe Program of Innovative Research Team of Soochow University。
文摘Recently circularly polarized luminescence(CPL)materials have attracted significant interest.Introducing reversible dynamic property to these materials has been a key focus in cutting-edge fields,such as in high-level information encryption.Here,we provided a novel and general strategy involving handednessselective filtration and ground-state chiral self-recovery(CSR)in double film system to address this issue.Based on this strategy,we achieved CPL switch through the reversible modulation of ground-state chirality including absorption and scattering circular dichroism(CD)signals over the full UV-visible wavelength range(365-700 nm)in a single azobenzene polymer(PAzo)film.More importantly,by flexibly changing the type of fluorescent films,it is convenient to achieve general excited-state CSR,that is reversible switching of full-color including ideal white(CIE coordinate(0.33,0.33)),as well as room-temperature phosphorescent CPL.All these CPL signals without almost any intensity decay after three cycles of onand-off switching.Experimental results indicated that the trans-cis isomerization and ordered rearrangement of azobenzene units in PAzo film were the fundamental reasons for realizing CPL switching.Finally,based on this system we achieved dynamic visual encryption and decryption process including multiple decryption methods.This study provides an effective method for constructing a universally applicable chiroptical switch in excited state.
