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
The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behav...The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.展开更多
An effective strategy for enhancing the heat resistance of polystyrene(PS)with regard to its glass transition temperature(T_(g))involves the anionic solution copolymerization of a-methylstyrene(AMS)with styrene(St),ty...An effective strategy for enhancing the heat resistance of polystyrene(PS)with regard to its glass transition temperature(T_(g))involves the anionic solution copolymerization of a-methylstyrene(AMS)with styrene(St),typically requires much lower temperature(-25℃)and multistep monomer feeding to achieve higher number-average molecular weight(M_(n))block copolymers.However,the anionic copolymerization of AMS and St under the mild temperature remains largely unexplored.This study systematically investigated the anionic copolymerization of AMS and St using n-BuLi in nonpolar solvent(-25℃ to 25℃)through both one-step and two-step approaches.We demonstrated that one-step copolymerization at 25℃ yielded only 1-3 terminal AMS units,with higher feed ratios(5 wt%-20 wt%)increasing AMS incorporation but reducing the exact molecular weight(MW)due to enhanced depolymerization,as evidenced by MALDI-TOF MS.Temperature-controlled AMS conversion at-15℃ achieved 98%AMS conversion(5 wt% feed)by suppressing side reactions and lowering the[M]_(e),while 50℃(near T_(C))almost prevented incorporation.Despite t-BuOK regulation induced broader PDI(1.24)via reactive[(polymer-Li)OR]K intermediates,while other systems showed narrow distributions,t-BuOK outperformed THF in enhancing AMS incorporation via efficient ion pair dissociation.In comparison,the two-step polymerization approach demonstrated superior performance,achieving both higher AMS conversion efficiency and preferential incorporation at the initiation end.At a 20 wt%AMS feed ratio,this method yielded copolymer chains containing up to 6 AMS units on average.Thermal analysis revealed a composition-dependent single T_(g),which exhibited a systematic increase with higher AMS incorporation content.These results collectively demonstrate the precise control over AMS incorporation and heat resistance achievable through the manipulation of polymerization conditions.展开更多
Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catal...Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.展开更多
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
Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effectiv...Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.展开更多
Shear stress overshoot in entangled polymer rheology is a hallmark of transient dynamics,but its microscopic origin remains under debate.Using molecular dynamics simulations,we investigate a two-step shear protocol co...Shear stress overshoot in entangled polymer rheology is a hallmark of transient dynamics,but its microscopic origin remains under debate.Using molecular dynamics simulations,we investigate a two-step shear protocol consisting of successive startup shears separated by a waiting period,with the first shear interrupted before the overshoot.In the homogeneous flow,the GLaMM theory captures the stress response during the first shear,but fails to reproduce the nonmonotonic dependence of the second stress overshoot(σ_(2max))on the waiting time.Contrary to the prediction of a nonmonotonic normal stress component σ_(yy)during the waiting period,our simulations show that σ_(yy),like the tube segment orientation(S_(xy)),the contour length of the primitive chain(L),and the entanglement number per chain(Z),relaxes monotonically toward equilibrium.At the strain corresponding to σ_(2max),both the tube segment orientation and the entanglement number per chain exhibit a nonmonotonic dependence on the waiting time that closely mirrors the behavior of σ_(2max),indicating that both factors play significant roles in governing(σ_(2max).Our findings are consistent with the interpretation of lanniruberto and Ma rrucci[ACS Macro.Lett.2014,3,552]for orientation effects and with the viewpoint of Wang et al.[Macromolecules 2013,46,3147]for entanglement effects,although the two explanations are rooted in distinct physical pictu res.These results provide new insights into the stress responses of entanglement polymer fluids and underscore the need for a more unified theoretical framework.展开更多
Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenge...Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenges in functional versatility and environmental adaptability.Here,we present the first synthesis of periodic selenium-incorporated PEAs(Se-PEAs)via a rapid,catalyst-free selenol-yne click polymerization process.By harnessing the versatility of selenium,we achieved precise modulation of material properties.The resulting Se-PEAs demonstrated tunable mechanical behavior,spanning rigid plastics to elastomers,alongside exceptional thermal stability and high optical clarity.Programmable degradation profiles ensure long-term stability in physiological environments while facilitating rapid oxidative degradation at the end of the lifecycle.Surface selenoniumization further conferred robust antibacterial efficacy without compromising mechanical integrity.This multifunctionality positions Se-PEAs as transformative materials for biomedical implants,sustainable packaging,and high-refractiveindex optics.Our work advanced functional polymer design and underscored the potential of selenium chemistry in addressing global challenges in terms of plastic waste and ecological sustainability.展开更多
Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity an...Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.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
Intrinsic stretchability is a promising attribute of polymer organic solar cells(OSCs).However,rigid molecular blocks typically exhibit poor tensile properties,rendering polymers vulnerable to mechanical stress.In thi...Intrinsic stretchability is a promising attribute of polymer organic solar cells(OSCs).However,rigid molecular blocks typically exhibit poor tensile properties,rendering polymers vulnerable to mechanical stress.In this study,we introduce a different approach utilizing all-small-molecule donors and acceptors to fabricate stretchable OSCs.An elastomer,styrene-b-ethylene-butylene-styrene(SEBS),was embedded to modulate film crystallization and stretchability.SEBS effectively confines the growth process of donors and acceptors,leading to enhancement of the crystallization quality,thus contributing to enhanced device efficiencies.Meanwhile,SEBS can absorb and release mechanical stress during stretching,thereby preventing mechanical degradation of donors and acceptors.The mechanical properties of the OSCs were significantly improved by the incorporation of SEBS.Notably,the crack-onset strain increased from 1.03% to 5.99% with SEBS embedding.These findings present a straightforward strategy for achieving stretchable OSCs using all small molecules,offering a different perspective for realizing stretchable devices.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
Oxidative stress is a critical risk factor for various disease complications in patients with end-stage renal disease,which may be further aggravated during hemodialysis.Herein,we prepared a hemodialysis membrane by i...Oxidative stress is a critical risk factor for various disease complications in patients with end-stage renal disease,which may be further aggravated during hemodialysis.Herein,we prepared a hemodialysis membrane by introducing poly(2-Acrylamide-2-methylpropanesulfonic acid-N-vinylpyrrolidone)(P(AMPS-VP))into the polyethersulfone(PES)membrane by simple in-situ polymerization and non-solvent phase sepa-ration(NIPS)method,followed by tannic acid(TA)coating construction through hydrogen bonding interaction,termed PES/P(AMPS-VP)-TA.The membrane can efficiently remove reactive nitrogen radicals(RNS)(DPPH•,89.96%;ABTS•+,90.49%)and reactive oxygen species(ROS)(O_(2)•^(−),90.45%),and has a very sta-ble antioxidant property.Meanwhile,the membrane does not cause hemolysis and coagulation,and has superior blood compatibility required by hemodialysis membrane.In addition,the dialysis performance of the membrane is improved compared with unmodified PES,which is beneficial for practical hemodialysis applications.This work provides a reference for industrial preparation of hemodialysis membranes,which is expected to be applied to reduce oxidative stress in hemodialysis patients.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financially supported by the National Natural Science Foundation of China(Nos.22341304,22303100 and 12205270)the National Key R&D Program of China(Nos.2023YFA1008800 and 2020YFA0713601)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC0180303)。
文摘The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.
基金financially supported by the National Natural Science Foundation of China(No.52373052)Fundamental Research Funds for the Central Universities(No.DUT24MS011)。
文摘An effective strategy for enhancing the heat resistance of polystyrene(PS)with regard to its glass transition temperature(T_(g))involves the anionic solution copolymerization of a-methylstyrene(AMS)with styrene(St),typically requires much lower temperature(-25℃)and multistep monomer feeding to achieve higher number-average molecular weight(M_(n))block copolymers.However,the anionic copolymerization of AMS and St under the mild temperature remains largely unexplored.This study systematically investigated the anionic copolymerization of AMS and St using n-BuLi in nonpolar solvent(-25℃ to 25℃)through both one-step and two-step approaches.We demonstrated that one-step copolymerization at 25℃ yielded only 1-3 terminal AMS units,with higher feed ratios(5 wt%-20 wt%)increasing AMS incorporation but reducing the exact molecular weight(MW)due to enhanced depolymerization,as evidenced by MALDI-TOF MS.Temperature-controlled AMS conversion at-15℃ achieved 98%AMS conversion(5 wt% feed)by suppressing side reactions and lowering the[M]_(e),while 50℃(near T_(C))almost prevented incorporation.Despite t-BuOK regulation induced broader PDI(1.24)via reactive[(polymer-Li)OR]K intermediates,while other systems showed narrow distributions,t-BuOK outperformed THF in enhancing AMS incorporation via efficient ion pair dissociation.In comparison,the two-step polymerization approach demonstrated superior performance,achieving both higher AMS conversion efficiency and preferential incorporation at the initiation end.At a 20 wt%AMS feed ratio,this method yielded copolymer chains containing up to 6 AMS units on average.Thermal analysis revealed a composition-dependent single T_(g),which exhibited a systematic increase with higher AMS incorporation content.These results collectively demonstrate the precise control over AMS incorporation and heat resistance achievable through the manipulation of polymerization conditions.
基金financial support from the National Natural Science Foundation of China(Nos.22401274,U23B6011)the Jilin Provincial Science and Technology Department Program(No.20250102070JC)。
文摘Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.
基金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financially supported by the National Natural Science Foundation of China(No.52473338)the National Natural Science Foundation of China(Nos.52173004 and 51873055)+3 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0540000)Advanced Materials-National Science and Technology Major Project(No.2025ZD0614000)Hebei Natural Science Foundation(No.E2022202015)Anhui Province Science and Technology Innovation Tackling Key Project(No.202423i08050025)。
文摘Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.
基金financially supported by the National Natural Science Foundation of China(Nos.22341303,22103079,and 22503003)the Shandong Provincial Natural Science Foundation(No.ZR2023QB232)the Beijing Institute of Technology Research Fund Program for Young Scholars(No.RCPT-6120250009)。
文摘Shear stress overshoot in entangled polymer rheology is a hallmark of transient dynamics,but its microscopic origin remains under debate.Using molecular dynamics simulations,we investigate a two-step shear protocol consisting of successive startup shears separated by a waiting period,with the first shear interrupted before the overshoot.In the homogeneous flow,the GLaMM theory captures the stress response during the first shear,but fails to reproduce the nonmonotonic dependence of the second stress overshoot(σ_(2max))on the waiting time.Contrary to the prediction of a nonmonotonic normal stress component σ_(yy)during the waiting period,our simulations show that σ_(yy),like the tube segment orientation(S_(xy)),the contour length of the primitive chain(L),and the entanglement number per chain(Z),relaxes monotonically toward equilibrium.At the strain corresponding to σ_(2max),both the tube segment orientation and the entanglement number per chain exhibit a nonmonotonic dependence on the waiting time that closely mirrors the behavior of σ_(2max),indicating that both factors play significant roles in governing(σ_(2max).Our findings are consistent with the interpretation of lanniruberto and Ma rrucci[ACS Macro.Lett.2014,3,552]for orientation effects and with the viewpoint of Wang et al.[Macromolecules 2013,46,3147]for entanglement effects,although the two explanations are rooted in distinct physical pictu res.These results provide new insights into the stress responses of entanglement polymer fluids and underscore the need for a more unified theoretical framework.
基金supported by the National Natural Science Foundation of China(21971177)the Natural Science Foundation of the Jiangsu Higher Education Institution of China(22KJA150004)+3 种基金the Suzhou Science and Technology Bureau(SZM2021008)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Jiangsu Key Laboratory of Advanced Functional Polymers Design and Application,Soochow University,Suzhou Medical and Industrial Cooperation Innovation Project(SZM2022011)the Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis and the Program of Innovative Research Team of Soochow University。
文摘Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenges in functional versatility and environmental adaptability.Here,we present the first synthesis of periodic selenium-incorporated PEAs(Se-PEAs)via a rapid,catalyst-free selenol-yne click polymerization process.By harnessing the versatility of selenium,we achieved precise modulation of material properties.The resulting Se-PEAs demonstrated tunable mechanical behavior,spanning rigid plastics to elastomers,alongside exceptional thermal stability and high optical clarity.Programmable degradation profiles ensure long-term stability in physiological environments while facilitating rapid oxidative degradation at the end of the lifecycle.Surface selenoniumization further conferred robust antibacterial efficacy without compromising mechanical integrity.This multifunctionality positions Se-PEAs as transformative materials for biomedical implants,sustainable packaging,and high-refractiveindex optics.Our work advanced functional polymer design and underscored the potential of selenium chemistry in addressing global challenges in terms of plastic waste and ecological sustainability.
基金financially supported by the International Cooperation Program from the Ministry of Science and Technology of Hubei Province(No.2023EHA069)Shenzhen Science and Technology Program(No.JCYJ20230807143702005)National Foreign Experts Program(No.G2022027015L)。
文摘Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.
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.52303239 and 51933001)Natural Science Foundation of Shandong Province(Nos.ZR2022QB141 and 2023HWYQ-087).
文摘Intrinsic stretchability is a promising attribute of polymer organic solar cells(OSCs).However,rigid molecular blocks typically exhibit poor tensile properties,rendering polymers vulnerable to mechanical stress.In this study,we introduce a different approach utilizing all-small-molecule donors and acceptors to fabricate stretchable OSCs.An elastomer,styrene-b-ethylene-butylene-styrene(SEBS),was embedded to modulate film crystallization and stretchability.SEBS effectively confines the growth process of donors and acceptors,leading to enhancement of the crystallization quality,thus contributing to enhanced device efficiencies.Meanwhile,SEBS can absorb and release mechanical stress during stretching,thereby preventing mechanical degradation of donors and acceptors.The mechanical properties of the OSCs were significantly improved by the incorporation of SEBS.Notably,the crack-onset strain increased from 1.03% to 5.99% with SEBS embedding.These findings present a straightforward strategy for achieving stretchable OSCs using all small molecules,offering a different perspective for realizing stretchable devices.
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financially sponsored by the State Key Research Development Program of China(Nos.2021YFB3800700 and 2021YFB3800703)the National Natural Science Foundation of China(Nos.52122306 and U21A2098)the Sichuan Province Science and Technology Program(No.2022NSFSC0382).
文摘Oxidative stress is a critical risk factor for various disease complications in patients with end-stage renal disease,which may be further aggravated during hemodialysis.Herein,we prepared a hemodialysis membrane by introducing poly(2-Acrylamide-2-methylpropanesulfonic acid-N-vinylpyrrolidone)(P(AMPS-VP))into the polyethersulfone(PES)membrane by simple in-situ polymerization and non-solvent phase sepa-ration(NIPS)method,followed by tannic acid(TA)coating construction through hydrogen bonding interaction,termed PES/P(AMPS-VP)-TA.The membrane can efficiently remove reactive nitrogen radicals(RNS)(DPPH•,89.96%;ABTS•+,90.49%)and reactive oxygen species(ROS)(O_(2)•^(−),90.45%),and has a very sta-ble antioxidant property.Meanwhile,the membrane does not cause hemolysis and coagulation,and has superior blood compatibility required by hemodialysis membrane.In addition,the dialysis performance of the membrane is improved compared with unmodified PES,which is beneficial for practical hemodialysis applications.This work provides a reference for industrial preparation of hemodialysis membranes,which is expected to be applied to reduce oxidative stress in hemodialysis patients.
