AIM:To investigate the biocompatibility and bacterial adhesion properties of light responsive materials(LRM)and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular le...AIM:To investigate the biocompatibility and bacterial adhesion properties of light responsive materials(LRM)and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular lenses(AIOLs).METHODS:Employing fundamental experimental research techniques,LRM with human lens epithelial cells(hLECs)and human retinal pigment epithelium cells(ARPE-19 cells)were co-cultured.Commercially available intraocular lenses(IOLs)were used as controls to perform cell counting kit-8(CCK-8),cell staining under varying light intensities,cell adhesion and bacterial adhesion experiments.RESULTS:LRM exhibited a stronger inhibitory effect on the proliferation of ARPE19 cells than commercially available IOLs when co-cultured with the undiluted extract for 96h(P<0.05).Under other culturing conditions,the effects on the proliferation of hLECs and ARPE-19 cells were not significantly different between the two materials.Under the influence of light irradiation at intensities of 200 and 300 mW/cm^(2),LRM demonstrated a markedly higher inhibitory effect on the survival of hLECs compared to commercially available IOLs(P<0.0001).They also showed a stronger suppressive effect on the survival rate of ARPE-19 cells,with significant differences observed at 200 mW/cm^(2)(P<0.001)and extremely significant differences at 300 mW/cm^(2)(P<0.0001).Additionally,compared to commercially available IOLs,LRM had a higher number of cells adhering to their surface(P<0.05),as well as a significantly greater number of adherent bacterium(P<0.0001).CONCLUSION:LRM,characterized by their excellent non-contact tunable deformability and low cytotoxicity to ocular tissues,show considerable potential for use in the fabrication of AIOLs.These materials demonstrate strong cell adhesion;however,during photothermal conversion processes involving shape deformation under various light intensities,the resultant temperature rise may harm surrounding cells.These factors suggest that while the material plays a positive role in reducing the incidence of posterior capsule opacification(PCO),it also poses potential risks for retinal damage.Additionally,the strong bacterial adhesion of these materials indicates an increased risk of endophthalmitis.展开更多
Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators d...Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators driven by magnetic force remotely.Nevertheless,the further study of magnetic responsive actuators with complex three-dimensional geometries and multiple functions is still limited by uncomplicated de-sign and flexible locomotion.This work provides a novel scheme integrating the origami method and modular designs,which defines the inner properties of magnetic material,extending the functions of magnetic responsive actuators with various modules.The directions of the inner magnetic moments can be programmed and the deformation degrees can be regulated by this approach,which promotes the fabrication of complicated soft actuators with multiple functions by integrating with modular designs.Especially,a movable actuator with various sensing modulus is designed by the origami method,which can perform the sensing application to external ultra-violet(UV),heat,and pH stimuli.Moreover,a mi-croneedle modular actuator which can be controlled wirelessly by a magnetic field was demonstrated for the potential application in the biomedical field.This proposed scheme for engineering magnetic respon-sive material with modular designs has shown great potential to improve the feasibility,versatility,and multiple functionalities of soft actuators.展开更多
Carbon-rich cycloarene macrocycles can adopt multiple atropisomeric forms due to steric hindrance restrictingσ-bond rotation.These distinct conformations exhibit variations in cavity structure,electronic properties,a...Carbon-rich cycloarene macrocycles can adopt multiple atropisomeric forms due to steric hindrance restrictingσ-bond rotation.These distinct conformations exhibit variations in cavity structure,electronic properties,and functional site distribution,leading to diverse molecular recognition and self-assembly behaviors.In recent years,research on carbon-rich cycloarene macrocyclic compounds has emerged as a cutting-edge and interdisciplinary focus in the fields of carbon-rich functional molecules and macrocyclic chemistry.This review provides a comprehensive overview of the development of atropisomers in carbon-rich cycloarene macrocycles,spanning their design and synthesis,optoelectronic properties,and supramolecular chemistry.展开更多
Multi-stimuli responsive materials controlled and coupled by two or more channels have a broad range of applications in the field of switches,memories,and molecular machines.The exploration of the material is currentl...Multi-stimuli responsive materials controlled and coupled by two or more channels have a broad range of applications in the field of switches,memories,and molecular machines.The exploration of the material is currently focused on the pure organic system,which limits the development o such materials greatly.In this work,we present a new chiral organic-inorganic hybrid salt,(R-3hydroxypyrrolidinium)_(2)[Fe(CN)_(5)(NO)](1),which exhibits rare multi-stimuli responsive behaviors in ther mal,mechanical and optical channels.In detail,1 undergoes a C2-P2_(1)22_(1) phase transition deriving from the thermal motion of organic cations with the increase of temperature,but the reverse transition can only be induced by mechanical pressure.Moreover,polycrystalline hybrid salt showed photo-responsive performance,i.e.,the ground-state N-bound nitrosyl ligand adopts two configurations in excited state caused by light in 532 nm irradiation,accompanying with a photo-induced structural transformation o the anionic framework.Namely,the thermal motion characteristics of organic cations,the photoresponse characteristics of anionic inorganic skeleton and the pressure characteristics from hydrogen bonds are si multaneously integrated in 1.This unprecedented coupling mechanism of multi-stimuli responses make1 a potential candidate for future multichannel data storage applications.展开更多
How the wave propagation analysis plays a key role in the studies of dynamic response of materials at high strain rates is analyzed. For the wave propagation technique, the followings are important: the loading and un...How the wave propagation analysis plays a key role in the studies of dynamic response of materials at high strain rates is analyzed. For the wave propagation technique, the followings are important: the loading and unloading constitutive relation presumed, the positions of the sensors embedded, the interactions between loading waves and unloading waves. For the split Hopkinson pressure bar (SHPB) technique, the assumption of one-dimensional stress wave propagation and the assumption of stress uniformity along the specimen should be satisfied. When the larger diameter bars are employed, the wave dispersion effects should be considered, including the high frequency oscillations, non-uniform stress distribution across the bar section, increase of rise time, and amplitude attenuation. The stress uniformity along the specimen is influenced by the reflection times in specimen, the wave impedance ratio of the specimen and the bar, and the waveform.展开更多
Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fi...Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fiber composites under mode-Ⅱ delamination damage. The load curve, AE relative energy, amplitude distribution, and amplitude spectrum are obtained and the delamination damage mechanism of the composites is investigated by the microscopic observation of a fractured specimen. The results show that the micro-damage accumulation around the crack tip region has a great effect on the evolutionary process of delamination. AE characteristics and amplitude spectrum represent the damage and the physical mechanism originating from the hierarchical microstructure. Our finding provides a novel aud feasible strategy to simultaneously evaluate the dynamic response and micro-damage mechanism for fiber composites.展开更多
Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a lar...Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a large challenge to design such stimulus responsive materials,especially functional materials having both dielectric switch and second harmonic generation(SHG).Here,a new stimuli-responsive switchable material [(CH_(3))_(3)N(CH_(2))_(2)Cl]_(2)]Mn(SCN)_(4)(H_(2)O)_(2)] was discovered as a potential secondharmonic generation(SHG) dielectric switch.It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions.In this work,we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation,which is tetramethylchloroethylamine(TMCEM) cation.By substituting H with a halogen,the increased steric hindrance of the molecular makes energy barrier increased,resulting in the reversible high-temperature phase transition.At the same time,the interactions of quasi-spherical cations and [Mn(SCN)_(4)(H_(2)O)_(2)]^(2-) anions affect a noncentrosymmetric structure to induce the SHG effect.These findings provide a new approach to design novel functional switch materials.展开更多
Constructingeco-friendlystimuli-responsivephosphorescence materials remains challenging and fascinating.Herein,we use natural cellulose as the rawmaterial to prepare pH-responsive room-temperature phosphorescent(RTP)m...Constructingeco-friendlystimuli-responsivephosphorescence materials remains challenging and fascinating.Herein,we use natural cellulose as the rawmaterial to prepare pH-responsive room-temperature phosphorescent(RTP)materials with excellent biodegradability by introducing anionic structures.The introduction of a phenylcarboxylate substituent not only promotes intersystem crossing but also brings about electrostatic-attractive and strong hydrogenbonding interactions,which enhance the intermolecular chain interactions.Therefore,the obtained anionic cellulose derivatives containing phenylcarboxylate groups exhibit ultra-long RTP.More intriguingly,these cellulose-based phosphorescent materials have a distinctive pH-responsive behavior.Under acidic conditions,the carboxylate is converted into the carboxylic acid,resulting in phosphorescence quenching.This process is reversible.Moreover,the obtained cellulosebased phosphorescent materials have excellent processability and can be easily processed into various material forms,such as film,coating,and pattern,by using eco-friendly aqueous solution processing strategies.Such proof-of-concept biomass-based phosphorescent materials with unique pH-responsive behavior and excellent processability have a huge potential in information encryption,advanced anti-counterfeiting,and food monitoring.展开更多
Structurally-modified acenes with a linear fusion ofπ-extended systems have shown highly attractive properties and promising applications in semiconductor materials,optoelectronic materials and others due to their un...Structurally-modified acenes with a linear fusion ofπ-extended systems have shown highly attractive properties and promising applications in semiconductor materials,optoelectronic materials and others due to their unique electronic structures.We have accessed a series of anthra/tetra/pentaquinodimethane-supported organoboranes,Mes^(*)B-A,Mes^(*)B-T and Mes^(*)B-P,with highly tunable emissions from blue to red(~680 nm)by controlling the number of fused benzene rings of the[n]acene core(n=3-5).Interestingly,these redox-switchable quinoid systems have chemically and electrochemically enabled two-electron oxidations,leading to dicationic anthracene,tetracene and pentacene segments(Mes^(*)B-A^(2+),Mes^(*)B-T^(2+)and Mes^(*)B-P^(2+))as evidenced by new absorption bands in the UV−vis−NIR spectra and spectroelectrochemical studies.Meanwhile,all the molecules feature aπ-conjugated,overcrowded ethylene structure that allows for a spin-state transition from closed-shell to the open-shell diradicals(Mes^(*)B-A^(2+),Mes^(*)B-T^(2+)and Mes^(*)B-P^(2+))under thermal conditions.This can further be confirmed by the variable-temperature(VT)^(1)H NMR and electron spin resonance(ESR)spectroscopy.These organoboranes also experienced an emission change in response to fluoride binding with electron-deficient boron centers.Our current work demonstrates not only the synthetic contribution to[n]acene-based luminescent materials,but also showcases multistate transformations for potential applications depending on well-tuned electronic,magnetic,electron transfer and charge transport mechanisms.展开更多
Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the...Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the hydrogen bond, known as the geometric H/D isotope effect. Herein, we report an organic crystal, diethylammonium hydrogen 1,4-terephthalate, exhibits a reversible structural phase transition and dielectric switching. Structural study shows the cations reside in channels formed by one-dimensional hydrogen-bonded anionic chains and undergo an order-disorder transition at around 206 K. The deuterated counterpart shows an elongation of the O…O hydrogen bond by about 0.005 A. This geometric isotope effect releases the internal pressure of the anionic host on the cation vips and results in a downward shift of the phase transition temperature by 10 K.展开更多
The tribological properties of newly developed friction material were evaluated by statistical analysis of the major affecting factors.The material for investigation was non-metallic friction material synergistically ...The tribological properties of newly developed friction material were evaluated by statistical analysis of the major affecting factors.The material for investigation was non-metallic friction material synergistically reinforced with aramid fibre and CaSO 4 whisker,which was developed for hoisting applications in coal mine.The response surface method（RSM）was employed to analyze the material performances affected by the independent and interactive effect of the factors under the normal working condition and severe working condition,respectively.Results showed that under the normal working condition,the newly developed material exhibited stable tribological properties which were insensitive to the test conditions.While under the severe working condition,the sliding velocity was the most dominant factor affecting the friction coefficient.Additionally,compared to the commercially available material,the modified material showed superior wear resistance and thermal stability.展开更多
In this paper,we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation.The investigat...In this paper,we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation.The investigation is carried out within the framework of the piecewise homogeneous body model by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity.It is assumed that there is a shear-spring-type imperfect contact between the layers,but a complete contact between the plate-strip and the rigid foundation.A mathematical model of the problem is constructed,and the governing equations of motion are solved by employing the finite element method（FEM）.Numerical results illustrating the influence of a change in the value of the shear-spring parameter on the dynamic response of the plate-strip are then presented.展开更多
Stimuli-responsive molecules are highly desirable in different scenario such as smart materials,bio-imaging,and environment monitoring.Herein,a series of hetero polycycles which show optical response toward chemical s...Stimuli-responsive molecules are highly desirable in different scenario such as smart materials,bio-imaging,and environment monitoring.Herein,a series of hetero polycycles which show optical response toward chemical stimuli are synthesized from trithiasumanene(TTS).The TTS is transformed into ortho-quinone form,which then undergoes three-component Debus-Radziszewski reaction with aldehydes and ammonia to give oxazole-fused TTS(2-6).The thiophene rings on 3-5 are selectively oxidized to thiophene-S,S-dioxides,affording 3-3O_(2)-5-3O_(2).It is found that the electronic structures of these compounds are governed by the sub-stituents on oxazole moiety and oxidation state of thiophene ring.Moreover,these hetero polycycles exhibit optical response toward different chemical stimuli.Particularly,compounds 6 and 3-3O_(2) can serve as fluorescence detectors for harmful chemicals sulfide ions(S2-/HS-)and aniline,respectively.This work indicates that TTS is a promising precursor for the creation of responsive materials.展开更多
Responsive soft materials capable of complex,reversible,and rapid geometric deformations under external stimuli hold significant potential for applications in minimally invasive medicine,wearable devices,and soft robo...Responsive soft materials capable of complex,reversible,and rapid geometric deformations under external stimuli hold significant potential for applications in minimally invasive medicine,wearable devices,and soft robotics.In this study,we present a novel approach for designing reconfigurable three dimensional(3D)deformable magnetic soft materials through photothermal programming.By embedding hard magnetic particles within a polymer matrix composed of fibrous polypyrrole(PPy)and semi-crystalline polymer,we develop magnetic composites that can be remotely controlled to achieve precise,programmable deformations under an external magnetic field.The key innovation lies in utilizing the photothermal effect of PPy,which temporarily alters the viscosity of the composite when irradiated with infrared light,allowing dynamic orientation of the magnetic particles.Upon cooling,the magnetic anisotropy is solidified,enabling rapid and reversible geometric changes.This method allows for intricate control over the magnetization distribution,leading to the development of multifunctional devices with various potential applications such as complex 3D deformations for soft robotics,multimodal electrical switches,rewritable quick response codes,and shape-adaptable grippers.Our study not only enhances the understanding of magnetic moment programming in soft materials but also opens new avenues for the design of adaptive and responsive materials for advanced technological applications.展开更多
Stimuli-responsive materials have shown promising applications in the areas of sensing,bioimaging,information encryption,and bioinspired camouflage.In particular,multi-stimuli-responsive materials represent a hot topi...Stimuli-responsive materials have shown promising applications in the areas of sensing,bioimaging,information encryption,and bioinspired camouflage.In particular,multi-stimuli-responsive materials represent a hot topic due to their modulated properties under multiple stimuli.Herein,we successfully developed multi-stimuli-responsive inks and a series of complex multi-stimuli-responsive 3-dimensional(3D)structures were fabricated via digital light processing 3D-printing technology.Notably,these complex 3D structures show shape memory,fast-response photochromic and thermochromic behavior,and excellent repeatability due to the combination of photochromic molecules(4-(2,2-bis(4-fluorophenyl)vinyl)benzyl methacrylate)and thermochromic pigments.Furthermore,a programmable encrypted box that changes colors and morphology by controlling temperature and ultraviolet irradiation was designed and printed,and this encrypted box exhibits strong security using OpenCV-based image recognition technology.This strategy provides a promising approach for the design of multi-stimuli-responsive materials and complex encryption systems in the future.展开更多
Solvent free DNA-surfactant melts are receiving continuous attractions in recent years.Their physical properties could be regulated via changing the alkyl chain length of surfactants.As an ideal external stimulus,ligh...Solvent free DNA-surfactant melts are receiving continuous attractions in recent years.Their physical properties could be regulated via changing the alkyl chain length of surfactants.As an ideal external stimulus,light has been used in the regulation of mechanical properties of DNA thermotropic liquid crystal(TLC)containing an azobenzene motif,while in this case,the UV light is the only effective excitation source.However,in comparison with visible light,UV light causes damage to DNA and has low tissue-penetration efficiency problem.In this work,a new type of DNA-didodecyldimethylammonium bromide(DNA-DDAB)TLCs fabricating with gold nanoparticles(AuNPs)was demonstrated.The visible light-induced photothermal effect of AuNPs could change the mechanical properties of AuNPs/DNA-DDAB TLCs,as shown by clearly boundary motion activity and viscoelasticity change.Furthermore,the ratio of AuNPs and charge stoichiometry of DNA:DDAB also affected photocurrent generation property of these DNA melts.The development of this visible light responsive DNA melt might facilitate the related studies in biomedicine and biomaterials.展开更多
Soft robots based on stimuli-responsive materials,such as those responsive to thermal,magnetic,or light stimuli,hold great potential for adaptive locomotion and multifunc-tionality in complex environments.Among these,...Soft robots based on stimuli-responsive materials,such as those responsive to thermal,magnetic,or light stimuli,hold great potential for adaptive locomotion and multifunc-tionality in complex environments.Among these,liquid crystal elastomers(LCEs)and magnetic microparticles have emerged as particularly promising candidates,leverag-ing their thermal responsiveness and magnetic controllability,respectively.However,integrating these modes to achieve synergistic multimodal actuation remains a signif-icant challenge.Here,we present the thermo-magnetic petal morphing robot,which combines LCEs with embedded magnetic microparticles to enable reversible shape morphing via remote light-to-thermal actuation and high-speed rolling locomotion under external magnetic fields.The robot can achieve rapid deformation under near-infrared light,transitioning from a closed spherical to an open cross-like configuration with consistent shape recovery across multiple cycles,and demonstrates a maximum locomotion speed of 30 body lengths per second,outperforming many state-of-the-art soft robots.Moreover,the robot’s performance remains robust across dry,wet,and underwater conditions,with adjustable magnetic particle concentrations allow-ing tunable actuation performance.Our work addresses the need for soft robots with enhanced versatility and adaptability in complex environments,paving the way for applications in areas such as targeted drug delivery and industrial material handling.展开更多
Modeling the response of material and chemical systems to electric fields remains a longstanding challenge.Machine learning interatomic potentials(MLIPs)offer an efficient and scalable alternative to quantum mechanica...Modeling the response of material and chemical systems to electric fields remains a longstanding challenge.Machine learning interatomic potentials(MLIPs)offer an efficient and scalable alternative to quantum mechanical methods,but do not by themselves incorporate electrical response.Here,we show that polarization and Born effective charge(BEC)tensors can be directly extracted from longrange MLIPs within the Latent Ewald Summation(LES)framework,solely by learning from energy and force data.Using this approach,we predict the infrared spectra of bulk water under zero or finite external electric fields,ionic conductivities of high-pressure superionic ice,and the phase transition and hysteresis in ferroelectric PbTiO_(3)perovskite.This work thus extends the capability of MLIPs to predict electrical response–without training on charges or polarization or BECs–and enables accurate modeling of electric-field-driven processes in diverse systems at scale.展开更多
The use of ultrashort laser pulses to manipulate properties or investigate a materials response on femtosecond time-scales enables detailed tracking of charge,spin,and lattice degrees of freedom.When pushing the limit...The use of ultrashort laser pulses to manipulate properties or investigate a materials response on femtosecond time-scales enables detailed tracking of charge,spin,and lattice degrees of freedom.When pushing the limits of experimental resolution,connection to theoretical modeling becomes increasingly important to infer causality relations.Weyl-semimetals are a particular class of materials of recent focus due to the topological protection of the Weyl-nodes,resulting in a number of fundamentally interesting phenomena.This work provides a first-principles framework based on timedependent density-functional theory for tracking the distribution of Weyl-nodes in the Brillouin-zone following an excitation by a laser pulse.Investigating the prototype material TaAs,we show that residual shifts in the Weyl-Nodes’position and energy distribution are induced by a photo-excitation within femto-seconds through band-structure renormalization.Further,we provide an analysis of the relaxation pathway of the photoexcited band-structure through lattice vibrations.展开更多
基金Supported by the National Natural Science Foundation of China(No.52073181,No.52273134).
文摘AIM:To investigate the biocompatibility and bacterial adhesion properties of light responsive materials(LRM)and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular lenses(AIOLs).METHODS:Employing fundamental experimental research techniques,LRM with human lens epithelial cells(hLECs)and human retinal pigment epithelium cells(ARPE-19 cells)were co-cultured.Commercially available intraocular lenses(IOLs)were used as controls to perform cell counting kit-8(CCK-8),cell staining under varying light intensities,cell adhesion and bacterial adhesion experiments.RESULTS:LRM exhibited a stronger inhibitory effect on the proliferation of ARPE19 cells than commercially available IOLs when co-cultured with the undiluted extract for 96h(P<0.05).Under other culturing conditions,the effects on the proliferation of hLECs and ARPE-19 cells were not significantly different between the two materials.Under the influence of light irradiation at intensities of 200 and 300 mW/cm^(2),LRM demonstrated a markedly higher inhibitory effect on the survival of hLECs compared to commercially available IOLs(P<0.0001).They also showed a stronger suppressive effect on the survival rate of ARPE-19 cells,with significant differences observed at 200 mW/cm^(2)(P<0.001)and extremely significant differences at 300 mW/cm^(2)(P<0.0001).Additionally,compared to commercially available IOLs,LRM had a higher number of cells adhering to their surface(P<0.05),as well as a significantly greater number of adherent bacterium(P<0.0001).CONCLUSION:LRM,characterized by their excellent non-contact tunable deformability and low cytotoxicity to ocular tissues,show considerable potential for use in the fabrication of AIOLs.These materials demonstrate strong cell adhesion;however,during photothermal conversion processes involving shape deformation under various light intensities,the resultant temperature rise may harm surrounding cells.These factors suggest that while the material plays a positive role in reducing the incidence of posterior capsule opacification(PCO),it also poses potential risks for retinal damage.Additionally,the strong bacterial adhesion of these materials indicates an increased risk of endophthalmitis.
基金support provided by the Hong Kong RGC Theme-based Research Scheme(No.AoE/M-402/20)Hong Kong RGC Area of Excellence Scheme(No.AoE/E-101/23-N)+1 种基金Hong Kong RGC Theme-based Research Scheme(No.T45-406/23-R)the Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Center.
文摘Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators driven by magnetic force remotely.Nevertheless,the further study of magnetic responsive actuators with complex three-dimensional geometries and multiple functions is still limited by uncomplicated de-sign and flexible locomotion.This work provides a novel scheme integrating the origami method and modular designs,which defines the inner properties of magnetic material,extending the functions of magnetic responsive actuators with various modules.The directions of the inner magnetic moments can be programmed and the deformation degrees can be regulated by this approach,which promotes the fabrication of complicated soft actuators with multiple functions by integrating with modular designs.Especially,a movable actuator with various sensing modulus is designed by the origami method,which can perform the sensing application to external ultra-violet(UV),heat,and pH stimuli.Moreover,a mi-croneedle modular actuator which can be controlled wirelessly by a magnetic field was demonstrated for the potential application in the biomedical field.This proposed scheme for engineering magnetic respon-sive material with modular designs has shown great potential to improve the feasibility,versatility,and multiple functionalities of soft actuators.
基金supported by the National Key R&D Program of China(2023YFA1406200)the National Natural Science Foundation of China(T2521005,12174144,12474009,12174146,and 124B2059)the Special Construction Project Fund for Shan-dong Province Taishan Scholars.
文摘Multifunctional optical responsive materials have grown increasingly pivotal in addressingthe escalating demands of sensing,detection,and anti-counterfeiting applications[1,2].These materials exhibit distinct visible optical variations upon exposure to external stimuli,such as pressure,temperature,light,solvents,pH fluctuations,or mechanical force.Fluorescent sensing and anti-counterfeiting technologies leveraging these optical responses have emerged as highly promising solutions.
基金H.-Y.Gong is grateful to the National Natural Science Foundation of China(No.92156009)for financial Support.
文摘Carbon-rich cycloarene macrocycles can adopt multiple atropisomeric forms due to steric hindrance restrictingσ-bond rotation.These distinct conformations exhibit variations in cavity structure,electronic properties,and functional site distribution,leading to diverse molecular recognition and self-assembly behaviors.In recent years,research on carbon-rich cycloarene macrocyclic compounds has emerged as a cutting-edge and interdisciplinary focus in the fields of carbon-rich functional molecules and macrocyclic chemistry.This review provides a comprehensive overview of the development of atropisomers in carbon-rich cycloarene macrocycles,spanning their design and synthesis,optoelectronic properties,and supramolecular chemistry.
基金supported by the National Natural Science Foundation of China(Nos.22071273 and 21821003)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.23lgzy001)。
文摘Multi-stimuli responsive materials controlled and coupled by two or more channels have a broad range of applications in the field of switches,memories,and molecular machines.The exploration of the material is currently focused on the pure organic system,which limits the development o such materials greatly.In this work,we present a new chiral organic-inorganic hybrid salt,(R-3hydroxypyrrolidinium)_(2)[Fe(CN)_(5)(NO)](1),which exhibits rare multi-stimuli responsive behaviors in ther mal,mechanical and optical channels.In detail,1 undergoes a C2-P2_(1)22_(1) phase transition deriving from the thermal motion of organic cations with the increase of temperature,but the reverse transition can only be induced by mechanical pressure.Moreover,polycrystalline hybrid salt showed photo-responsive performance,i.e.,the ground-state N-bound nitrosyl ligand adopts two configurations in excited state caused by light in 532 nm irradiation,accompanying with a photo-induced structural transformation o the anionic framework.Namely,the thermal motion characteristics of organic cations,the photoresponse characteristics of anionic inorganic skeleton and the pressure characteristics from hydrogen bonds are si multaneously integrated in 1.This unprecedented coupling mechanism of multi-stimuli responses make1 a potential candidate for future multichannel data storage applications.
文摘How the wave propagation analysis plays a key role in the studies of dynamic response of materials at high strain rates is analyzed. For the wave propagation technique, the followings are important: the loading and unloading constitutive relation presumed, the positions of the sensors embedded, the interactions between loading waves and unloading waves. For the split Hopkinson pressure bar (SHPB) technique, the assumption of one-dimensional stress wave propagation and the assumption of stress uniformity along the specimen should be satisfied. When the larger diameter bars are employed, the wave dispersion effects should be considered, including the high frequency oscillations, non-uniform stress distribution across the bar section, increase of rise time, and amplitude attenuation. The stress uniformity along the specimen is influenced by the reflection times in specimen, the wave impedance ratio of the specimen and the bar, and the waveform.
基金Supported by the Natural Science Foundation of Hebei Province under Grant No E2012201084the National University Students’ Innovative Training Program under Grant No 201410075004
文摘Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fiber composites under mode-Ⅱ delamination damage. The load curve, AE relative energy, amplitude distribution, and amplitude spectrum are obtained and the delamination damage mechanism of the composites is investigated by the microscopic observation of a fractured specimen. The results show that the micro-damage accumulation around the crack tip region has a great effect on the evolutionary process of delamination. AE characteristics and amplitude spectrum represent the damage and the physical mechanism originating from the hierarchical microstructure. Our finding provides a novel aud feasible strategy to simultaneously evaluate the dynamic response and micro-damage mechanism for fiber composites.
基金supported by the National Natural Science Foundation of China(Nos.21673038,21771037,21805033)Natural Science Foundation of Jiangsu Province(JSNSF,No.BK20170659)。
文摘Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a large challenge to design such stimulus responsive materials,especially functional materials having both dielectric switch and second harmonic generation(SHG).Here,a new stimuli-responsive switchable material [(CH_(3))_(3)N(CH_(2))_(2)Cl]_(2)]Mn(SCN)_(4)(H_(2)O)_(2)] was discovered as a potential secondharmonic generation(SHG) dielectric switch.It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions.In this work,we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation,which is tetramethylchloroethylamine(TMCEM) cation.By substituting H with a halogen,the increased steric hindrance of the molecular makes energy barrier increased,resulting in the reversible high-temperature phase transition.At the same time,the interactions of quasi-spherical cations and [Mn(SCN)_(4)(H_(2)O)_(2)]^(2-) anions affect a noncentrosymmetric structure to induce the SHG effect.These findings provide a new approach to design novel functional switch materials.
基金supported by the Youth Innovation Promotion Association CAS(grant no.2018040)(J.M.Z.)the National Natural Science Foundation of China(grant nos.52173292 and U2004211)(J.M.Z.and J.Z.)the National Key Research and Development Project(grant no.2020YFC1910303)(J.Z.).
文摘Constructingeco-friendlystimuli-responsivephosphorescence materials remains challenging and fascinating.Herein,we use natural cellulose as the rawmaterial to prepare pH-responsive room-temperature phosphorescent(RTP)materials with excellent biodegradability by introducing anionic structures.The introduction of a phenylcarboxylate substituent not only promotes intersystem crossing but also brings about electrostatic-attractive and strong hydrogenbonding interactions,which enhance the intermolecular chain interactions.Therefore,the obtained anionic cellulose derivatives containing phenylcarboxylate groups exhibit ultra-long RTP.More intriguingly,these cellulose-based phosphorescent materials have a distinctive pH-responsive behavior.Under acidic conditions,the carboxylate is converted into the carboxylic acid,resulting in phosphorescence quenching.This process is reversible.Moreover,the obtained cellulosebased phosphorescent materials have excellent processability and can be easily processed into various material forms,such as film,coating,and pattern,by using eco-friendly aqueous solution processing strategies.Such proof-of-concept biomass-based phosphorescent materials with unique pH-responsive behavior and excellent processability have a huge potential in information encryption,advanced anti-counterfeiting,and food monitoring.
基金supported by the Beijing Natural Science Foundation(No.2232024).
文摘Structurally-modified acenes with a linear fusion ofπ-extended systems have shown highly attractive properties and promising applications in semiconductor materials,optoelectronic materials and others due to their unique electronic structures.We have accessed a series of anthra/tetra/pentaquinodimethane-supported organoboranes,Mes^(*)B-A,Mes^(*)B-T and Mes^(*)B-P,with highly tunable emissions from blue to red(~680 nm)by controlling the number of fused benzene rings of the[n]acene core(n=3-5).Interestingly,these redox-switchable quinoid systems have chemically and electrochemically enabled two-electron oxidations,leading to dicationic anthracene,tetracene and pentacene segments(Mes^(*)B-A^(2+),Mes^(*)B-T^(2+)and Mes^(*)B-P^(2+))as evidenced by new absorption bands in the UV−vis−NIR spectra and spectroelectrochemical studies.Meanwhile,all the molecules feature aπ-conjugated,overcrowded ethylene structure that allows for a spin-state transition from closed-shell to the open-shell diradicals(Mes^(*)B-A^(2+),Mes^(*)B-T^(2+)and Mes^(*)B-P^(2+))under thermal conditions.This can further be confirmed by the variable-temperature(VT)^(1)H NMR and electron spin resonance(ESR)spectroscopy.These organoboranes also experienced an emission change in response to fluoride binding with electron-deficient boron centers.Our current work demonstrates not only the synthetic contribution to[n]acene-based luminescent materials,but also showcases multistate transformations for potential applications depending on well-tuned electronic,magnetic,electron transfer and charge transport mechanisms.
基金financially supported by the National Natural Science Foundation of China (Nos. 21875035 and 21991144)。
文摘Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the hydrogen bond, known as the geometric H/D isotope effect. Herein, we report an organic crystal, diethylammonium hydrogen 1,4-terephthalate, exhibits a reversible structural phase transition and dielectric switching. Structural study shows the cations reside in channels formed by one-dimensional hydrogen-bonded anionic chains and undergo an order-disorder transition at around 206 K. The deuterated counterpart shows an elongation of the O…O hydrogen bond by about 0.005 A. This geometric isotope effect releases the internal pressure of the anionic host on the cation vips and results in a downward shift of the phase transition temperature by 10 K.
基金Funded by National Natural Science Foundation of China(No. 50875253)Natural Science Foundation of Jiangsu Province of China(No. BK2008127)Key Project of Chinese Ministry of Education(NO.107054)
文摘The tribological properties of newly developed friction material were evaluated by statistical analysis of the major affecting factors.The material for investigation was non-metallic friction material synergistically reinforced with aramid fibre and CaSO 4 whisker,which was developed for hoisting applications in coal mine.The response surface method（RSM）was employed to analyze the material performances affected by the independent and interactive effect of the factors under the normal working condition and severe working condition,respectively.Results showed that under the normal working condition,the newly developed material exhibited stable tribological properties which were insensitive to the test conditions.While under the severe working condition,the sliding velocity was the most dominant factor affecting the friction coefficient.Additionally,compared to the commercially available material,the modified material showed superior wear resistance and thermal stability.
基金a member of a research project supported by the Research Fund of Kastamonu University via project num-ber Kü-BAP01/2016-4
文摘In this paper,we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation.The investigation is carried out within the framework of the piecewise homogeneous body model by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity.It is assumed that there is a shear-spring-type imperfect contact between the layers,but a complete contact between the plate-strip and the rigid foundation.A mathematical model of the problem is constructed,and the governing equations of motion are solved by employing the finite element method（FEM）.Numerical results illustrating the influence of a change in the value of the shear-spring parameter on the dynamic response of the plate-strip are then presented.
基金This work was supported by the National Key R&D Program of China(No.2017YFA0204903)the National Natural Science Foundation of China(No.21871119).
文摘Stimuli-responsive molecules are highly desirable in different scenario such as smart materials,bio-imaging,and environment monitoring.Herein,a series of hetero polycycles which show optical response toward chemical stimuli are synthesized from trithiasumanene(TTS).The TTS is transformed into ortho-quinone form,which then undergoes three-component Debus-Radziszewski reaction with aldehydes and ammonia to give oxazole-fused TTS(2-6).The thiophene rings on 3-5 are selectively oxidized to thiophene-S,S-dioxides,affording 3-3O_(2)-5-3O_(2).It is found that the electronic structures of these compounds are governed by the sub-stituents on oxazole moiety and oxidation state of thiophene ring.Moreover,these hetero polycycles exhibit optical response toward different chemical stimuli.Particularly,compounds 6 and 3-3O_(2) can serve as fluorescence detectors for harmful chemicals sulfide ions(S2-/HS-)and aniline,respectively.This work indicates that TTS is a promising precursor for the creation of responsive materials.
基金supported by the National Natural Science Foundation of China(52225307 and 22105193)the CAS Project for Young Scientists in Basic Research(YSBR-004)+1 种基金the Fundamental Research Funds for the Central Universities(20720220007 and 20720220011)partially carried out at the University of Science and Technology of China(USTC)Center of Micro and Nanoscale Research and Fabrication。
文摘Responsive soft materials capable of complex,reversible,and rapid geometric deformations under external stimuli hold significant potential for applications in minimally invasive medicine,wearable devices,and soft robotics.In this study,we present a novel approach for designing reconfigurable three dimensional(3D)deformable magnetic soft materials through photothermal programming.By embedding hard magnetic particles within a polymer matrix composed of fibrous polypyrrole(PPy)and semi-crystalline polymer,we develop magnetic composites that can be remotely controlled to achieve precise,programmable deformations under an external magnetic field.The key innovation lies in utilizing the photothermal effect of PPy,which temporarily alters the viscosity of the composite when irradiated with infrared light,allowing dynamic orientation of the magnetic particles.Upon cooling,the magnetic anisotropy is solidified,enabling rapid and reversible geometric changes.This method allows for intricate control over the magnetization distribution,leading to the development of multifunctional devices with various potential applications such as complex 3D deformations for soft robotics,multimodal electrical switches,rewritable quick response codes,and shape-adaptable grippers.Our study not only enhances the understanding of magnetic moment programming in soft materials but also opens new avenues for the design of adaptive and responsive materials for advanced technological applications.
基金support from the NSF of China(62275217)the Natural Science Basic Research Program of Shaanxi Province(2024JC-JCQN-51)the Fundamental Research Funds for the Central Universities.
文摘Stimuli-responsive materials have shown promising applications in the areas of sensing,bioimaging,information encryption,and bioinspired camouflage.In particular,multi-stimuli-responsive materials represent a hot topic due to their modulated properties under multiple stimuli.Herein,we successfully developed multi-stimuli-responsive inks and a series of complex multi-stimuli-responsive 3-dimensional(3D)structures were fabricated via digital light processing 3D-printing technology.Notably,these complex 3D structures show shape memory,fast-response photochromic and thermochromic behavior,and excellent repeatability due to the combination of photochromic molecules(4-(2,2-bis(4-fluorophenyl)vinyl)benzyl methacrylate)and thermochromic pigments.Furthermore,a programmable encrypted box that changes colors and morphology by controlling temperature and ultraviolet irradiation was designed and printed,and this encrypted box exhibits strong security using OpenCV-based image recognition technology.This strategy provides a promising approach for the design of multi-stimuli-responsive materials and complex encryption systems in the future.
基金supported by the National Natural Science Foundation of China(21805150)Natural Science Foundation of Shandong Province(ZR2019BB034)+1 种基金the Taishan Scholar Program of Shandong Province of China(ts20110829)Science and Technology Planning Project of Guangdong Province of China(2016B030309002)
文摘Solvent free DNA-surfactant melts are receiving continuous attractions in recent years.Their physical properties could be regulated via changing the alkyl chain length of surfactants.As an ideal external stimulus,light has been used in the regulation of mechanical properties of DNA thermotropic liquid crystal(TLC)containing an azobenzene motif,while in this case,the UV light is the only effective excitation source.However,in comparison with visible light,UV light causes damage to DNA and has low tissue-penetration efficiency problem.In this work,a new type of DNA-didodecyldimethylammonium bromide(DNA-DDAB)TLCs fabricating with gold nanoparticles(AuNPs)was demonstrated.The visible light-induced photothermal effect of AuNPs could change the mechanical properties of AuNPs/DNA-DDAB TLCs,as shown by clearly boundary motion activity and viscoelasticity change.Furthermore,the ratio of AuNPs and charge stoichiometry of DNA:DDAB also affected photocurrent generation property of these DNA melts.The development of this visible light responsive DNA melt might facilitate the related studies in biomedicine and biomaterials.
基金Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20210324132810026,KQTD20210811090146075,GXWD20220811164014001National Natural Science Foundation of China,Grant/Award Numbers:52375175,52005128Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2024A1515240015。
文摘Soft robots based on stimuli-responsive materials,such as those responsive to thermal,magnetic,or light stimuli,hold great potential for adaptive locomotion and multifunc-tionality in complex environments.Among these,liquid crystal elastomers(LCEs)and magnetic microparticles have emerged as particularly promising candidates,leverag-ing their thermal responsiveness and magnetic controllability,respectively.However,integrating these modes to achieve synergistic multimodal actuation remains a signif-icant challenge.Here,we present the thermo-magnetic petal morphing robot,which combines LCEs with embedded magnetic microparticles to enable reversible shape morphing via remote light-to-thermal actuation and high-speed rolling locomotion under external magnetic fields.The robot can achieve rapid deformation under near-infrared light,transitioning from a closed spherical to an open cross-like configuration with consistent shape recovery across multiple cycles,and demonstrates a maximum locomotion speed of 30 body lengths per second,outperforming many state-of-the-art soft robots.Moreover,the robot’s performance remains robust across dry,wet,and underwater conditions,with adjustable magnetic particle concentrations allow-ing tunable actuation performance.Our work addresses the need for soft robots with enhanced versatility and adaptability in complex environments,paving the way for applications in areas such as targeted drug delivery and industrial material handling.
基金funding from the BIDMaP Postdoctoral Fellowship.
文摘Modeling the response of material and chemical systems to electric fields remains a longstanding challenge.Machine learning interatomic potentials(MLIPs)offer an efficient and scalable alternative to quantum mechanical methods,but do not by themselves incorporate electrical response.Here,we show that polarization and Born effective charge(BEC)tensors can be directly extracted from longrange MLIPs within the Latent Ewald Summation(LES)framework,solely by learning from energy and force data.Using this approach,we predict the infrared spectra of bulk water under zero or finite external electric fields,ionic conductivities of high-pressure superionic ice,and the phase transition and hysteresis in ferroelectric PbTiO_(3)perovskite.This work thus extends the capability of MLIPs to predict electrical response–without training on charges or polarization or BECs–and enables accurate modeling of electric-field-driven processes in diverse systems at scale.
基金The Carl Trygger foundations is acknowledged for funding through grant CTS20:153O.G.Acknowledges financial support from the Swedish Research Council(VR)through grant 2019-03901+3 种基金European Research Council through the Synergy Grant 854843-FASTCORRThe computations were/was enabled by resources provided by the National Academic Infrastructure for Supercomputing in Sweden(NAISS)and the Swedish National Infrastructure for Computing(SNIC)at NSC and PSCpartially funded by the Swedish Research Council through grant agreements no.2022-06725 and no.2018-05973This work was supported by the Ministry of Education,Youth and Sports of the Czech Republic through the e-INFRA CZ(ID:90254).
文摘The use of ultrashort laser pulses to manipulate properties or investigate a materials response on femtosecond time-scales enables detailed tracking of charge,spin,and lattice degrees of freedom.When pushing the limits of experimental resolution,connection to theoretical modeling becomes increasingly important to infer causality relations.Weyl-semimetals are a particular class of materials of recent focus due to the topological protection of the Weyl-nodes,resulting in a number of fundamentally interesting phenomena.This work provides a first-principles framework based on timedependent density-functional theory for tracking the distribution of Weyl-nodes in the Brillouin-zone following an excitation by a laser pulse.Investigating the prototype material TaAs,we show that residual shifts in the Weyl-Nodes’position and energy distribution are induced by a photo-excitation within femto-seconds through band-structure renormalization.Further,we provide an analysis of the relaxation pathway of the photoexcited band-structure through lattice vibrations.
