A squarylium dye is dissolved in 4-cyano-4＇-pentylbiphenyl （SCB） and oriented by sandwiching mixtures between two pieces of rubbed glass plates. The optical absorption spectra of the oriented squarylium dye-5CB lay...A squarylium dye is dissolved in 4-cyano-4＇-pentylbiphenyl （SCB） and oriented by sandwiching mixtures between two pieces of rubbed glass plates. The optical absorption spectra of the oriented squarylium dye-5CB layers exhibit high anisotropy. The third-order nonlinear optical responses and susceptibilities X^（3）e of squarylium dye in 5CB are measured with light polarizations parallel and perpendicular to the orientational direction by the resonant femtosecond degenerate four-wave mixing （DFWM） technique. Temporal profiles of the DFWM signal of the oriented squarylium dye-5CB layers with light polarizations parallel and perpendicular to the orientational direction are measured with a time resolution of 0.3ps （FWHM）, and are found to consist of two components, i.e., the coherent instantaneous nonlinear response and slow response due to the formation of excited molecules. A high anisotropic ratio of x^（3）e, 10.8 ：k 1.2, is observed for the oriented layers.展开更多
The global polymer industry encounters great challenges as plastic waste is generated and accumulated,causing severe plastic pollution in our environment.Conventional polymers are dependent on non-renewable fossil fee...The global polymer industry encounters great challenges as plastic waste is generated and accumulated,causing severe plastic pollution in our environment.Conventional polymers are dependent on non-renewable fossil feedstocks and are hard to recycle.This linear“produce-use-discard”pattern is no longer sustainable,and the development of circular polymer systems—materials that can be efficiently depolymerized,recycled,and transformed into high-value products—has emerged as a critical research frontier with significant environmental and economic implications[[1],[2],[3],[4],[5],[6],[7],[8]].Insightful perspectives and reviews are brought together in this special issue of Fundamental Research,“Polymer Depolymerization,Recycling,and High-value Transformation.”The collection highlights innovative chemical strategies,emerging technologies,and interdisciplinary approaches reshaping our understanding of polymer sustainability.By presenting work from leading researchers,this issue aims to advance the development of circular polymer systems and inspire new solutions to the plastic waste crisis.展开更多
Functional materials with circularly polarized luminescence(CPL)have attracted tremendous attention due to their promising applications in three-dimensional dis-plays,chiral recognition and catalysis,photoelectronic d...Functional materials with circularly polarized luminescence(CPL)have attracted tremendous attention due to their promising applications in three-dimensional dis-plays,chiral recognition and catalysis,photoelectronic devices,contrast imaging,information encryption,and otherfields.Among various CPL-active materials,poly-meric systems with aggregation-induced emission(AIE)have emerged as excellent candidates because of their efficient aggregate-statefluorescence,large solid-state dissymmetry factor,excellent processibility,diversified self-assembly behaviors,and readily switchable CPL properties.This review summarizes and discusses the recent progress as well as future perspective of diverse AIE polymer systems with CPL,including CPL-active covalent AIE polymers,CPL-active supramolecular AIE polymers,and AIEgen/polymer composites with CPL.According to the loca-tion or introduction method of AIEgen in polymer structures,this review further divides CPL-active covalent AIE polymers into three categories,including polymers with AIEgen in main chains,polymers with AIEgen in side chains,and CPL-active polymers with clusterization-triggered emission.CPL-active supramolecular AIE polymers are discussed based on the driving force for the formation of supramolecular polymers,including host–vip interactions,metal coordination,and other non-covalent interactions.Moreover,examples on the construction of CPL-active AIEgen/polymer composites by physically mixing AIEgens with chi-ral(supra)polymers are also presented.This review is anticipated to provide readers with an overall view on the design strategies of CPL-active AIE polymers,and facil-itate further research on the development of CPL materials and AIE polymers with advanced applications.展开更多
Rheological measurement has been an effective method to characterize the structure and properties for multiphase/multi-component polymers,owing to its sensitivity to the structure change of hetero-geneous systems.In t...Rheological measurement has been an effective method to characterize the structure and properties for multiphase/multi-component polymers,owing to its sensitivity to the structure change of hetero-geneous systems.In this article,recent progress in the studies on the morphology/structure and rheological properties of heterogeneous systems is summarized,mainly reporting the findings of the authors and their collaborators,involving the correlation between the morphology and viscoelastic relaxation of LCST-type polymer blends,the microstructure and linear/nonlinear viscoelastic behavior of block copolymers,time scaling of shear-induced crystallization and rheological response of poly-olefins,and the relationship between the structure/properties and rheological behavior of filled polymer blends.It is suggested that a thorough understanding of the characteristic rheological response to the morphology/structure evolution of multiphase/multi-component polymers facilitates researchers’op-timizing the morphology/structure and ultimate mechanical properties of polymer materials.展开更多
In this work,shear strain modeling in materials consisting of a thin polymer layer(~15 nm),adhesive bonded to a rigid substrate,considered not to be impacted by deformation,was performed.A discrete-continuum model of ...In this work,shear strain modeling in materials consisting of a thin polymer layer(~15 nm),adhesive bonded to a rigid substrate,considered not to be impacted by deformation,was performed.A discrete-continuum model of chains system with a given stiffness with polar groups is developed.The polymer chain was considered in the framework of the persistene model,and the polar groups were based on the lattice model on the tetragonal lattice.It was assumed that the main contribution to the energy of interchain interactions is due to the potential of the polar groups and was calculated using the Metropolis algorithm.The potential interactions between the nearest polar groups of chains included the energy of dipole–dipole interactions(Keesom energy)and the Lennard–Jones potential.It is taken into account that the possible orientations of the polar groups are determined by the average elongation of the chain.Calculations showed that the dependence of free energy on the interchain distance has two minima.The first minimum is characterized by the orientational ordering of the polar groups,the second—by their disordered state.The depth and position of the minima depend on temperature,bending stiffness of the chain,the modulus of the dipole moment of the polar groups and the depth of the potential well in the Lennard–Jones energy.A step-by-step simulation of shear strain in a polymer layer in an orientationally disordered state was carried out.The obtained stress–strain diagrams make it possible to estimate the value of the elastic limit and also to determine the stresses at the points of phase transitions from a disordered to an orientationally ordered state.展开更多
Polymer–solvent systems exhibit complex solvation behaviours encompassing a diverse range of phenomena,including swelling,gelation,and dispersion.Accurate interpretation is often hindered by subjectivity,particularly...Polymer–solvent systems exhibit complex solvation behaviours encompassing a diverse range of phenomena,including swelling,gelation,and dispersion.Accurate interpretation is often hindered by subjectivity,particularly in manual rapid screening assessments.While computer vision models hold significant promise to replace the reliance on human evaluation for inference,their adoption is limited by the lack of domain-specific datasets tailored,in our case,to polymer–solvent systems.To bridge this gap,we conducted extensive screenings of polymers with diverse physical and chemical properties across various solvents,capturing solvation characteristics through images,videos,and image–text captions.This dataset informed the development of a multi-model vision assistant,integrating computer vision and vision-language approaches to autonomously detect,infer,and contextualise polymer–solvent interactions.The system combines a 2D-CNN module for static solvation state classification,a hybrid 2D/3D-CNN module to capture temporal dynamics,and a BLIP-2-based contextualisation module to generate descriptive captions for solvation behaviours,including vial orientation,solvent discolouration,and polymer interaction states.Computationally efficient,this vision assistant provides an accurate,objective,and scalable solution in interpreting solvation behaviours,fit for autonomous platforms and high-throughput workflows in material discovery and analysis.展开更多
文摘A squarylium dye is dissolved in 4-cyano-4＇-pentylbiphenyl （SCB） and oriented by sandwiching mixtures between two pieces of rubbed glass plates. The optical absorption spectra of the oriented squarylium dye-5CB layers exhibit high anisotropy. The third-order nonlinear optical responses and susceptibilities X^（3）e of squarylium dye in 5CB are measured with light polarizations parallel and perpendicular to the orientational direction by the resonant femtosecond degenerate four-wave mixing （DFWM） technique. Temporal profiles of the DFWM signal of the oriented squarylium dye-5CB layers with light polarizations parallel and perpendicular to the orientational direction are measured with a time resolution of 0.3ps （FWHM）, and are found to consist of two components, i.e., the coherent instantaneous nonlinear response and slow response due to the formation of excited molecules. A high anisotropic ratio of x^（3）e, 10.8 ：k 1.2, is observed for the oriented layers.
文摘The global polymer industry encounters great challenges as plastic waste is generated and accumulated,causing severe plastic pollution in our environment.Conventional polymers are dependent on non-renewable fossil feedstocks and are hard to recycle.This linear“produce-use-discard”pattern is no longer sustainable,and the development of circular polymer systems—materials that can be efficiently depolymerized,recycled,and transformed into high-value products—has emerged as a critical research frontier with significant environmental and economic implications[[1],[2],[3],[4],[5],[6],[7],[8]].Insightful perspectives and reviews are brought together in this special issue of Fundamental Research,“Polymer Depolymerization,Recycling,and High-value Transformation.”The collection highlights innovative chemical strategies,emerging technologies,and interdisciplinary approaches reshaping our understanding of polymer sustainability.By presenting work from leading researchers,this issue aims to advance the development of circular polymer systems and inspire new solutions to the plastic waste crisis.
基金National Natural Science Foundation of China,Grant/Award Number:22271197Science and Technology Plan of Shenzhen,Grant/Award Numbers:JCYJ20220531102601003,JCYJ20190808142403590。
文摘Functional materials with circularly polarized luminescence(CPL)have attracted tremendous attention due to their promising applications in three-dimensional dis-plays,chiral recognition and catalysis,photoelectronic devices,contrast imaging,information encryption,and otherfields.Among various CPL-active materials,poly-meric systems with aggregation-induced emission(AIE)have emerged as excellent candidates because of their efficient aggregate-statefluorescence,large solid-state dissymmetry factor,excellent processibility,diversified self-assembly behaviors,and readily switchable CPL properties.This review summarizes and discusses the recent progress as well as future perspective of diverse AIE polymer systems with CPL,including CPL-active covalent AIE polymers,CPL-active supramolecular AIE polymers,and AIEgen/polymer composites with CPL.According to the loca-tion or introduction method of AIEgen in polymer structures,this review further divides CPL-active covalent AIE polymers into three categories,including polymers with AIEgen in main chains,polymers with AIEgen in side chains,and CPL-active polymers with clusterization-triggered emission.CPL-active supramolecular AIE polymers are discussed based on the driving force for the formation of supramolecular polymers,including host–vip interactions,metal coordination,and other non-covalent interactions.Moreover,examples on the construction of CPL-active AIEgen/polymer composites by physically mixing AIEgens with chi-ral(supra)polymers are also presented.This review is anticipated to provide readers with an overall view on the design strategies of CPL-active AIE polymers,and facil-itate further research on the development of CPL materials and AIE polymers with advanced applications.
基金Supported by the National Basic Research Program of China(Grant No.2005CB623800)Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20040335077)
文摘Rheological measurement has been an effective method to characterize the structure and properties for multiphase/multi-component polymers,owing to its sensitivity to the structure change of hetero-geneous systems.In this article,recent progress in the studies on the morphology/structure and rheological properties of heterogeneous systems is summarized,mainly reporting the findings of the authors and their collaborators,involving the correlation between the morphology and viscoelastic relaxation of LCST-type polymer blends,the microstructure and linear/nonlinear viscoelastic behavior of block copolymers,time scaling of shear-induced crystallization and rheological response of poly-olefins,and the relationship between the structure/properties and rheological behavior of filled polymer blends.It is suggested that a thorough understanding of the characteristic rheological response to the morphology/structure evolution of multiphase/multi-component polymers facilitates researchers’op-timizing the morphology/structure and ultimate mechanical properties of polymer materials.
基金The study was supported by the Russian Foundation for Basic Research,Project No.19-42-350001.
文摘In this work,shear strain modeling in materials consisting of a thin polymer layer(~15 nm),adhesive bonded to a rigid substrate,considered not to be impacted by deformation,was performed.A discrete-continuum model of chains system with a given stiffness with polar groups is developed.The polymer chain was considered in the framework of the persistene model,and the polar groups were based on the lattice model on the tetragonal lattice.It was assumed that the main contribution to the energy of interchain interactions is due to the potential of the polar groups and was calculated using the Metropolis algorithm.The potential interactions between the nearest polar groups of chains included the energy of dipole–dipole interactions(Keesom energy)and the Lennard–Jones potential.It is taken into account that the possible orientations of the polar groups are determined by the average elongation of the chain.Calculations showed that the dependence of free energy on the interchain distance has two minima.The first minimum is characterized by the orientational ordering of the polar groups,the second—by their disordered state.The depth and position of the minima depend on temperature,bending stiffness of the chain,the modulus of the dipole moment of the polar groups and the depth of the potential well in the Lennard–Jones energy.A step-by-step simulation of shear strain in a polymer layer in an orientationally disordered state was carried out.The obtained stress–strain diagrams make it possible to estimate the value of the elastic limit and also to determine the stresses at the points of phase transitions from a disordered to an orientationally ordered state.
基金Green Rose Chemistry for their collaboration in this research and for providing both financial and technical support through an Innovate UK grant(10097443),subcontracted to the Innovation Centre in Digital Molecular Technologies(iDMT,Yusuf Hamied Department of Chemistry,University of Cambridge)Z.J.L.acknowledges support from the Marie Skłodowska-Curie Actions Innovative Training Networks through a Marie Curie Fellowship(101072732)as part of Horizon Europe 2021,underwritten by United Kingdom Research and Innovation(UKRI EP/X034763/1)+1 种基金Z.E.acknowledges financial support from the Mastercard Foundation ScholarshipThis work was further supported by the facilities and resources provided by the Innovation Centre in Digital Molecular Technologies,An element in Fig.1a was created using BioRender templates and modified prior to use.
文摘Polymer–solvent systems exhibit complex solvation behaviours encompassing a diverse range of phenomena,including swelling,gelation,and dispersion.Accurate interpretation is often hindered by subjectivity,particularly in manual rapid screening assessments.While computer vision models hold significant promise to replace the reliance on human evaluation for inference,their adoption is limited by the lack of domain-specific datasets tailored,in our case,to polymer–solvent systems.To bridge this gap,we conducted extensive screenings of polymers with diverse physical and chemical properties across various solvents,capturing solvation characteristics through images,videos,and image–text captions.This dataset informed the development of a multi-model vision assistant,integrating computer vision and vision-language approaches to autonomously detect,infer,and contextualise polymer–solvent interactions.The system combines a 2D-CNN module for static solvation state classification,a hybrid 2D/3D-CNN module to capture temporal dynamics,and a BLIP-2-based contextualisation module to generate descriptive captions for solvation behaviours,including vial orientation,solvent discolouration,and polymer interaction states.Computationally efficient,this vision assistant provides an accurate,objective,and scalable solution in interpreting solvation behaviours,fit for autonomous platforms and high-throughput workflows in material discovery and analysis.
