In this work, a series of high performance bio-based polyurethanes（bio-PUs） were synthesized from polylactide（PLA）-based diols, different diisocyanates（TDI, MDI, HDI, IPDI） and chain extender 1,4-butanediol, in ...In this work, a series of high performance bio-based polyurethanes（bio-PUs） were synthesized from polylactide（PLA）-based diols, different diisocyanates（TDI, MDI, HDI, IPDI） and chain extender 1,4-butanediol, in which different soft and hard segments are used to adjust their transition temperatures and mechanical properties. Poly（lactide-co-caprolactone）copolymer diols（co-PLAols） instead of PLA diols as the soft segment improved the thermal stability and mechanical properties of the synthesized bio-PUs. Among them, MDI-based bio-PUs have the highest T_g（43.8 °C）, tensile strength（23.5 MPa） and modulus（380.8 MPa）, while HDI-based bio-PUs have the lowest T_g（21.4 °C） and highest elongation at break（580%）. Especially, the bio-PUs synthesized from co-PLAols and MDI demonstrate better mechanical properties,closed to petroleum-based commodities. Furthermore, the obtained bio-PUs display good shape memory properties at body temperature and cytocompatibility. Therefore, these bio-PUs are promising for applications in biomedical fields.展开更多
Smart elastomers have attracted great interest due to their excellent adaptability to changing environments and affinity to living organisms,characterized by their ability to undergo programmable deformations or prope...Smart elastomers have attracted great interest due to their excellent adaptability to changing environments and affinity to living organisms,characterized by their ability to undergo programmable deformations or property changes in response to external stimuli(e.g.,heat,light,pH,or electric/magnetic fields).They exhibit huge potential to drive the innovation of soft actuators,robotics,biomedical devices,and wearable electronics.This special issue of Chinese Journal of Polymer Science(CJPS)is dedicated to showcasing cutting-edge advancements in liquid crystal elastomers,hydrogels and the related soft actuators,with a focus on the design,synthesis,characterization,and application of stimuli-responsive soft elastomers and their integration into functional actuation systems.展开更多
Integrated conductive elastomers with excellent mechanical performance,stable high conductivity,self-healing capabilities,and high transparency are critical for advancing wearable devices.Nevertheless,achieving an opt...Integrated conductive elastomers with excellent mechanical performance,stable high conductivity,self-healing capabilities,and high transparency are critical for advancing wearable devices.Nevertheless,achieving an optimal balance among these properties remains a significant challenge.Herein,through in situ free-radical copolymerization of 2-[2-(2-methoxyethoxy)ethoxy]ethyl acrylate(TEEA)and vinylimidazole(VI)in the presence of polyethylene glycol(PEG;Mn=400),tough P(TEEA-co-VI)/PEG elastomers with multiple functionalities were prepared,in which P(TEEA-co-VI)was dynamically cross-linked by imidazole-Zn^(2+)metal coordination crosslinks,and physically blended with PEG as polymer electrolyte to form a homogeneous mixture.Notably,Zn^(2+)has a negligible impact on the polymerization process,allowing for the in situ formation of numerous imidazole-Zn^(2+)metal coordination crosslinks,which can effectively dissipate energy upon stretching to largely reinforce the elastomers.The obtained P(TEEA-co-VI)/PEG elastomers exhibited a high toughness of 10.0 MJ·m^(-3) with a high tensile strength of 3.3 MPa and a large elongation at break of 645%,along with outstanding self-healing capabilities due to the dynamic coordination crosslinks.Moreover,because of the miscibility of PEG with PTEEA copolymer matrix,and Li+can form weak coordination interactions with the ethoxy(EO)units in PEG and PTEEA,acting as a bridge to integrate PEG into the elastomer network.The resulted P(TEEA-co-VI)/PEG elastomers showed high transparency(92%)and stable high conductivity of 1.09×10_(-4) S·cm^(-1).In summary,the obtained elastomers exhibited a well-balanced combination of high toughness,high ionic conductivity,excellent self-healing capabilities,and high transparency,making them promising for applications in flexible strain sensors.展开更多
With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have comma...With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have commanded considerable attention.Bio-based polyurethane,on account of its remarkable physical and chemical properties,green,sustainable and renewable capacity,as well as its structural design capabilities,has drawn widespread attention and numerous studies have been carried out.It has gradually started to substitute traditional petroleum-based polyurethane materials in road engineering.Nevertheless,the application of bio-based polyurethane materials in road engineering remains in the exploratory phase.To stimulate the application research of bio-based polyurethane materials in road engineering and offer additional research directions,this paper reviews the research advancements of bio-based polyurethane materials and their applications in road engineering.The fundamental classification of bio-based polyurethane is introduced.The characteristics and challenges associated with various preparation methods for bio-based polyurethane are described.The influence of bio-based polyurethane on road engineering materials are analyzed.The evaluation indicators of bio-based polyurethane within the life cycle of road engineering are investigated.Finally,the development tendency towards in road engineering applications are forecasted.This paper provides a reference for the study of bio-based polyurethane materials in road engineering applications.展开更多
Conductive elastomers combining micromechanical sensitivity,lightweight adaptability,and environmental sustainability are critically needed for advanced flexible electronics requiring precise responsiveness and long-t...Conductive elastomers combining micromechanical sensitivity,lightweight adaptability,and environmental sustainability are critically needed for advanced flexible electronics requiring precise responsiveness and long-term wearability;however,the integration of these properties remains a significant challenge.Here,we present a biomass-derived conductive elastomer featuring a rationally engineered dynamic crosslinked network integrated with a tunable microporous architecture.This structural design imparts pronounced micromechanical sensitivity,an ultralow density(~0.25 g cm^(−3)),and superior mechanical compliance for adaptive deformation.Moreover,the unique micro-spring effect derived from the porous architecture ensures exceptional stretchability(>500%elongation at break)and superior resilience,delivering immediate and stable electrical response under both subtle(<1%)and large(>200%)mechanical stimuli.Intrinsic dynamic interactions endow the elastomer with efficient room temperature self-healing and complete recyclability without compromising performance.First-principles simulations clarify the mechanisms behind micropore formation and the resulting functionality.Beyond its facile and mild fabrication process,this work establishes a scalable route toward high-performance,sustainable conductive elastomers tailored for next-generation soft electronics.展开更多
The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the cha...The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the characteristics of being renewable,environmentally friendly,and having excellent barrier properties.They have become an important choice in fields such as food packaging,agricultural film covering,and medical protection.This review systematically analyzes the design and research of this type of material,classifying biobased and biodegradable barrier materials based on the sources of raw materials and synthesis pathways.It also provides a detailed introduction to the latest research progress of biobased and biodegradable barrier materials,discussing the synthesis methods and improvement measures of their barrier properties.Subsequently,it analyzes the related technologies for enhancing the barrier properties of biobased and biodegradable barrier materials,and finally looks forward to the directions that future research should focus on,promoting the transition of biobased and biodegradable barrier materials from the laboratory to industrial applications.展开更多
The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed th...The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed the bio-based electrotechnical epoxy resins based on magnolol.High-performance epoxy resin(DGEMT)with a double crosslinked points and its composites(Al_(2)O_(3)/DGEMT)were obtained taking advantages of the two bifunctional groups(allyl and phenolic hydroxyl groups)of magnolol.Benefitting from the distinctive structure of DGEMT,the Al_(2)O_(3)/DGEMT composites exhibited the advantages of intrinsically high thermal conductivity,high insulation,and low dielectric loss.The AC breakdown strength and thermal conductivity of Al_(2)O_(3)/DGEMT composites were 35.5 kV/mm and 1.19 W·m-1·K-1,respectively,which were 15.6%and 52.6%higher than those of petroleum-based composites(Al_(2)O_(3)/DGEBA).And its dielectric loss tanδ=0.0046 was 20.7%lower than that of Al_(2)O_(3)/DGEBA.Furthermore,the mechanical,thermal and processing properties of Al_(2)O_(3)/DGEMT are fully comparable to those of Al_(2)O_(3)/DGEBA.This work confirms the feasibility of manufacturing environmentally friendly power equipment using bio-based epoxy resins,which has excellent engineering applications.展开更多
Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that ...Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.展开更多
The development of high-performance functional composites has become a research hotspot in response to the hazards of over-heating and electromagnetic radiation in modern electronic devices.Herein,we grew magnetic Fe_...The development of high-performance functional composites has become a research hotspot in response to the hazards of over-heating and electromagnetic radiation in modern electronic devices.Herein,we grew magnetic Fe_(3)O_(4)particles in situ on the MXene layer to obtain an MXene@Fe_(3)O_(4)composite with rich heterogeneous interfaces.Owing to the unique heterostructure and the synergistic effects of multiple electromagnetic wave absorption mechanisms,the composite achieved a minimum reflection loss of-27.14 dB and an effect-ive absorption bandwidth of 2.05 GHz at an absorption thickness of 2 mm.Moreover,the MXene@Fe_(3)O_(4)composite could be encapsu-lated in thermoplastic polyurethane(TPU)via thermal curing.The obtained composite elastomer exhibited a strong tensile strength,and its thermal diffusivity was 113%higher than that of pure TPU.Such additional mechanical properties and thermal conduction features render this composite elastomer an advanced electromagnetic absorber to adapt to the ever-changing environment for expanding practical applications.展开更多
Liquid crystal elastomers(LCEs)are advanced materials characterized by their rubber-like hyperelasticity and liquid crystal phase transitions,offering exceptional mechanical properties.The development of smart mechani...Liquid crystal elastomers(LCEs)are advanced materials characterized by their rubber-like hyperelasticity and liquid crystal phase transitions,offering exceptional mechanical properties.The development of smart mechanical metamaterials(SMMs)from LCEs expands the potential for controlling mechanical responses and achieving nonlinear behaviors not possible with traditional metamaterials.However,the challenge lies in managing the interplay between nonlinear material responses and structural complexity,making the inverse design of LCE-based SMMs exceptionally demanding.In this paper,we introduce a design framework for LCE smart mechanical metamaterials that leverages neural networks and evolution strategies(ES)to optimize designs with nonlinear mechanical responses.Our approach involves constructing a flexible,unit-cell-based metamaterial model that integrates the soft elastic behavior and thermo-mechanical coupling of LCEs.The combination of microscopic liquid crystal molecule rotation and macroscopic block rotation enables highly tunable and nonlinear mechanical behaviors,of which the precise inverse design of stress-stretch responses is obtained via neural networks combined with ES.In addition,stimuli responses in the liquid crystal elastomers enable real-time adaptability and achieve tailored stress plateaus that are not possible with traditional metamaterials.Our findings provide new pathways in the design and optimization of advanced materials in flexible electronic devices,intelligent actuators,and systems for energy absorption and dissipation.展开更多
By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permea...By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permeability and heavy oil reservoirs under varying temperature conditions.The results demonstrate that this system effectively reduces oil–water interfacial tension,achieving an ultra-low interfacial tension state.The static oil washing efficiency of oil sands exceeds 85%,the average pressure reduction rate reaches 21.55%,and the oil recovery rate improves by 13.54%.These enhancements significantly increase the system’s ability to dissolve oilbased blockages,thereby lowering water injection pressure caused by organic fouling,increasing the injection volume of injection wells,and ultimately improving oil recovery efficiency.展开更多
Purpose–This study aims to carry out optimization and improvement work on the artificial climate aging and ultraviolet aging tests of elastic expansion joints in railway concrete bridges.Design/methodology/approach–...Purpose–This study aims to carry out optimization and improvement work on the artificial climate aging and ultraviolet aging tests of elastic expansion joints in railway concrete bridges.Design/methodology/approach–Three polyurethane elastomer specimens with different chemical compositions were adopted.According to relevant standard regulations,the aging test process was analyzed and evaluated in detail,and reasonable improvement suggestions were put forward.The effectiveness was verified through actual tests.Findings–The final test results indicate that the combination of artificial climate aging tests and ultraviolet aging tests is technically feasible and has significant advantages in practical applications.Originality/value–This study optimizes the conditions of artificial climate aging and ultraviolet aging tests,compares the advantages and disadvantages of different aging test methods,and proposes a combined test scheme of artificial climate aging and ultraviolet aging and verifies its effectiveness.The results provide valuable reference for simulating the actual aging behavior of polyurethane elastomers,material performance evaluation,and application in railway bridge engineering.It is conducive to promoting the reasonable application of this material in engineering,improving engineering quality,reducing costs,and has economic and social benefits.展开更多
With the rise in environmental awareness,the development of smart polymer materials is gradually becoming environmentally friendly and sustainable.Fluorescent liquid crystal elastomers(LCE)can change their shape or op...With the rise in environmental awareness,the development of smart polymer materials is gradually becoming environmentally friendly and sustainable.Fluorescent liquid crystal elastomers(LCE)can change their shape or optical properties in response to external stimuli,showing great potential for applications in sensing,information storage,and encryption.However,their life cycle is often unsustainable and not in line with the circular economy model.Based on the principle of green chemistry,a fluorescent LCE was developed through the co-polymerization of multiple monomers with 1,2-dithiolane end groups,which exhibited excellent self-healing,reprocessing,and closed-loop recyclability.In addition,by tailoring the phase transition temperature of the LCE,the transparency and fluorescence intensity of the resulting material can change at a low temperature of 8.0℃.By further integrating light or acid/base-triggered fluorescence information,a proof-of-concept for temperature monitoring during short-time vaccine transportation using the reusable fluorescent LCE film is demonstrated.This study establishes a new environmentally friendly manufacturing strategy for multifunctional LCE materials.展开更多
This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck o...This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck of precise anisotropic control in LCEs.Mechanically pre-programmed hierarchical LCE structures responsive to near-infrared(NIR)light were fabricated:the oriented constrained actuator achieves asymmetric contraction under NIR irradiation,enabling reversible switching between helix and planar morphologies with multi-terrain grasping capability;the biomimetic vine-like helical actuator,composed of Ag nanowire photothermal layers combined with helical LCE,utilizes temperaturegradient-induced phase transition wave propagation to achieve NIR-controlled climbing motion;the M?bius topology actuator realizes reversible deformation or self-locking states by tuning the twist angle(180°/360°);based on these,a bioinspired koala-like concentric soft robot was constructed,successfully demonstrating tree trunk climbing.This study reveals that artificial helical stretching significantly enhances the molecular chain orientation of LCEs(surpassing uniaxial stretching),reaching up to 1000%pre-strain,and the Ag NWs/LCE/PI(Polyimide)tri-layer structure achieves efficient photothermal-mechanical energy conversion via localized surface plasmon resonance(LSPR).This study provides a new paradigm for soft robotics material design and topological programming,demonstrating the potential for remote operation and adaptive grasping.展开更多
Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations a...Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations and environmental aggressors,silicone elastomers exhibit relatively low stiffness,limiting their direct applicability in seismic isolation.This study investigates the effect of fumed silica as a reinforcing filler to enhance the mechanical properties of laminated silicone elastomeric bearings.Elastomeric samples were fabricated with varying fumed silica proportions and subjected to Shore A hardness,uniaxial tensile,and lap shear tests to assess the influence of filler content.Additionally,quasi-static tests were conducted on reduced-scale bearing prototypes under combined vertical compression and cyclic horizontal shear to evaluate their seismic isolation performance.The results demonstrate that fumed silica reinforcement significantly increases stiffness,as evidenced by higher Shore A hardness values.However,a trade-off was observed in tensile properties,with reductions in tensile strength and elongation at break.Despite this,the equivalent elastic modulus did not show substantial variation up to large deformations,indicating that stiffness is preserved under most working conditions.Lap shear tests showed that fumed silica improves shear resistance,while quasi-static tests revealed inelastic behavior with small increases in equivalent shear coefficients but no substantial loss in damping ratios.These findings suggest that fumed silica reinforcement enhances silicone elastomers’stiffness and shear resistance while maintaining moderate damping properties,making it a promising approach for improving the mechanical performance of elastomeric bearings in seismic isolation applications.展开更多
Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)...Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.展开更多
In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance ...In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance of lightweight concrete.Through a mixture design approach,five formulations were selected and thoroughly characterized.The analysis of iso-response curves enabled an in-depth assessment of the cross-effects between formulation parameters and their interactions on the final properties of the material.The results show that integrating millet husks leads to a significant reduction in density,reaching up to 21%,while maintaining notable mechanical performance.A balanced formulation of sand and fibers achieved a maximum compressive strength of 12.11 MPa,demonstrating that,under specific conditions,plant fibers actively contribute to the structural integrity of the composite.In tensile strength,the positive influence of fibers is even more pronounced,with a maximum resistance of 8.62 MPa,highlighting their role in enhancing material cohesion.From a thermal perspective,millet husks reduce both thermal conductivity and effusivity,thereby limiting heat transfer and accumulation within the composite.Iso-response curve analysis reveals that these effects are directly linked to the proportions of the constituents and that achieving an optimal balance between sand,fibers,and cement is key to maximizing performance.These findings demonstrate that the adopted approach allows moving beyond conventional substitution methods by identifying optimal configurations for the design of lightweight bio-based concretes that are both strong and insulating,thereby confirming the potential of millet husks in developing lightweight concretes suitable for sustainable construction applications.展开更多
In recent years,flexible ionic conductors have made remarkable progress in the fields of energy storage devices and flexible sensors.However,most of these materials still face challenges such as the difficult trade-of...In recent years,flexible ionic conductors have made remarkable progress in the fields of energy storage devices and flexible sensors.However,most of these materials still face challenges such as the difficult trade-off between stretchability and high mechanical strength,as well as insufficient ionic conductivity.Among them,polymerizable deep eutectic solvents(PDES),which possess both hydrogen bond network construction capabilities and ionic conduction properties,have demonstrated great advantages in the synthesis of flexible ionic conductors.Herein,we report an ionic conductive elastomer(ICE)named PCHS-X based on PDES composed of 2-(methacryloyloxy)-N,N,N-trimethylammonium methyl sulfate(MA-MS),choline chloride(ChCl),and 2-hydroxyethyl acrylate(HEA).The introduction of MA-MS enabled the polymer network to form abundant hydrogen bonds,endowing PCHS-X with excellent mechanical strength,high transparency,favorable ionic conductivity,self-adhesiveness,and self-healing efficiency.When used as a strain sensor,the PCHS-X exhibits highly sensitive strain response,along with good stability and durability,allowing it to accurately monitor the movement of human body parts such as fingers,wrists,elbows,and knees.Additionally,owing to the enhanced ionic mobility at higher temperatures,this material also possesses excellent temperature sensing performance,enabling the fabrication of simple temperature sensors that can sensitively respond to temperature changes.This research provides new strategies for the practical applications of flexible electronic devices in fields such as wearable health monitoring and intelligent human-machine interaction.展开更多
An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthrolin...An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.展开更多
Conventional rotary actuators mainly rely on electric or hydraulic/pneumatic motors to convert energy into mechanical motion,making them one of the most widely used actuation methods in industrial manufacturing,roboti...Conventional rotary actuators mainly rely on electric or hydraulic/pneumatic motors to convert energy into mechanical motion,making them one of the most widely used actuation methods in industrial manufacturing,robotics,and automation control.However,these traditional actuators often suffer from limitations in operability and applicability due to their complex structures,bulky systems,high energy consumption,and severe mechanical wear.Liquid crystal elastomers(LCEs)have been increasingly used for programmable actuation applications,owing to their ability to undergo large,reversible,and anisotropic deformations in response to external stimuli.In this work,we propose a compact flexible rotary joint(FRJ)based on LCEs.To describe the thermo-mechanical coupled behaviors,a constitutive model is developed and further implemented for finite element analysis(FEA).Through combining experiments and simulations,we quantify the dynamic rotational behavior of the rotor rotating relative to the base driven by the induced strain of the FRJ under cyclic thermal stimuli.The proposed rotary joint features a simple structure,lightweight design,low energy consumption,and easy control.These characteristics endow it with significant potential for miniaturization and integration in the field of soft actuation and robotics.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21404112)Ningbo Key Scientific and Technological Project(No.2014B10023)+2 种基金Ningbo Natural Science Foundation(No.2015A610016)Open Project of Key Laboratory of Marine Materials and Related Technologies(No.2016K07)Ningbo Science and Technology Innovation Team(No.2015B11003)
文摘In this work, a series of high performance bio-based polyurethanes（bio-PUs） were synthesized from polylactide（PLA）-based diols, different diisocyanates（TDI, MDI, HDI, IPDI） and chain extender 1,4-butanediol, in which different soft and hard segments are used to adjust their transition temperatures and mechanical properties. Poly（lactide-co-caprolactone）copolymer diols（co-PLAols） instead of PLA diols as the soft segment improved the thermal stability and mechanical properties of the synthesized bio-PUs. Among them, MDI-based bio-PUs have the highest T_g（43.8 °C）, tensile strength（23.5 MPa） and modulus（380.8 MPa）, while HDI-based bio-PUs have the lowest T_g（21.4 °C） and highest elongation at break（580%）. Especially, the bio-PUs synthesized from co-PLAols and MDI demonstrate better mechanical properties,closed to petroleum-based commodities. Furthermore, the obtained bio-PUs display good shape memory properties at body temperature and cytocompatibility. Therefore, these bio-PUs are promising for applications in biomedical fields.
文摘Smart elastomers have attracted great interest due to their excellent adaptability to changing environments and affinity to living organisms,characterized by their ability to undergo programmable deformations or property changes in response to external stimuli(e.g.,heat,light,pH,or electric/magnetic fields).They exhibit huge potential to drive the innovation of soft actuators,robotics,biomedical devices,and wearable electronics.This special issue of Chinese Journal of Polymer Science(CJPS)is dedicated to showcasing cutting-edge advancements in liquid crystal elastomers,hydrogels and the related soft actuators,with a focus on the design,synthesis,characterization,and application of stimuli-responsive soft elastomers and their integration into functional actuation systems.
基金supported by the National Natural Science Foundation of China(Nos.52273023,51973103,and 21774069).
文摘Integrated conductive elastomers with excellent mechanical performance,stable high conductivity,self-healing capabilities,and high transparency are critical for advancing wearable devices.Nevertheless,achieving an optimal balance among these properties remains a significant challenge.Herein,through in situ free-radical copolymerization of 2-[2-(2-methoxyethoxy)ethoxy]ethyl acrylate(TEEA)and vinylimidazole(VI)in the presence of polyethylene glycol(PEG;Mn=400),tough P(TEEA-co-VI)/PEG elastomers with multiple functionalities were prepared,in which P(TEEA-co-VI)was dynamically cross-linked by imidazole-Zn^(2+)metal coordination crosslinks,and physically blended with PEG as polymer electrolyte to form a homogeneous mixture.Notably,Zn^(2+)has a negligible impact on the polymerization process,allowing for the in situ formation of numerous imidazole-Zn^(2+)metal coordination crosslinks,which can effectively dissipate energy upon stretching to largely reinforce the elastomers.The obtained P(TEEA-co-VI)/PEG elastomers exhibited a high toughness of 10.0 MJ·m^(-3) with a high tensile strength of 3.3 MPa and a large elongation at break of 645%,along with outstanding self-healing capabilities due to the dynamic coordination crosslinks.Moreover,because of the miscibility of PEG with PTEEA copolymer matrix,and Li+can form weak coordination interactions with the ethoxy(EO)units in PEG and PTEEA,acting as a bridge to integrate PEG into the elastomer network.The resulted P(TEEA-co-VI)/PEG elastomers showed high transparency(92%)and stable high conductivity of 1.09×10_(-4) S·cm^(-1).In summary,the obtained elastomers exhibited a well-balanced combination of high toughness,high ionic conductivity,excellent self-healing capabilities,and high transparency,making them promising for applications in flexible strain sensors.
基金supported by the Key R&D Project in Shaanxi Province(No.2024GX-YBXM-371)Shaanxi Qinchuangyuan Scientists+Engineers Team Construction Project(2025QCY-KXJ-141).
文摘With the escalating global emphasis on environmental conservation and sustainable development,enhancing the service quality and durability of road surfaces and facilitating the green development of highways have commanded considerable attention.Bio-based polyurethane,on account of its remarkable physical and chemical properties,green,sustainable and renewable capacity,as well as its structural design capabilities,has drawn widespread attention and numerous studies have been carried out.It has gradually started to substitute traditional petroleum-based polyurethane materials in road engineering.Nevertheless,the application of bio-based polyurethane materials in road engineering remains in the exploratory phase.To stimulate the application research of bio-based polyurethane materials in road engineering and offer additional research directions,this paper reviews the research advancements of bio-based polyurethane materials and their applications in road engineering.The fundamental classification of bio-based polyurethane is introduced.The characteristics and challenges associated with various preparation methods for bio-based polyurethane are described.The influence of bio-based polyurethane on road engineering materials are analyzed.The evaluation indicators of bio-based polyurethane within the life cycle of road engineering are investigated.Finally,the development tendency towards in road engineering applications are forecasted.This paper provides a reference for the study of bio-based polyurethane materials in road engineering applications.
基金supported by National Natural Science Foundation of China(No.52103044)Double First-Class Initiative University of Science and Technology of China(KY2400000037)the Young Talent Programme(GG2400007009).
文摘Conductive elastomers combining micromechanical sensitivity,lightweight adaptability,and environmental sustainability are critically needed for advanced flexible electronics requiring precise responsiveness and long-term wearability;however,the integration of these properties remains a significant challenge.Here,we present a biomass-derived conductive elastomer featuring a rationally engineered dynamic crosslinked network integrated with a tunable microporous architecture.This structural design imparts pronounced micromechanical sensitivity,an ultralow density(~0.25 g cm^(−3)),and superior mechanical compliance for adaptive deformation.Moreover,the unique micro-spring effect derived from the porous architecture ensures exceptional stretchability(>500%elongation at break)and superior resilience,delivering immediate and stable electrical response under both subtle(<1%)and large(>200%)mechanical stimuli.Intrinsic dynamic interactions endow the elastomer with efficient room temperature self-healing and complete recyclability without compromising performance.First-principles simulations clarify the mechanisms behind micropore formation and the resulting functionality.Beyond its facile and mild fabrication process,this work establishes a scalable route toward high-performance,sustainable conductive elastomers tailored for next-generation soft electronics.
基金supported by the Science and Technology Research Project of Henan Province(222102230031)Key Scientific Research Projects of Colleges and Universities in Henan Province(23A430018)Natural Science Foundation of Henan(252300420267).
文摘The current global shortage of oil resources and the pollution problems caused by traditional barrier materials urgently require the search for new substitutes.Biodegradable bio-based barrier materials possess the characteristics of being renewable,environmentally friendly,and having excellent barrier properties.They have become an important choice in fields such as food packaging,agricultural film covering,and medical protection.This review systematically analyzes the design and research of this type of material,classifying biobased and biodegradable barrier materials based on the sources of raw materials and synthesis pathways.It also provides a detailed introduction to the latest research progress of biobased and biodegradable barrier materials,discussing the synthesis methods and improvement measures of their barrier properties.Subsequently,it analyzes the related technologies for enhancing the barrier properties of biobased and biodegradable barrier materials,and finally looks forward to the directions that future research should focus on,promoting the transition of biobased and biodegradable barrier materials from the laboratory to industrial applications.
基金supported by the China Postdoctoral Science Foundation(No.2023M743622)Natural Science Foundation of Ningbo City(No.2024J109)+2 种基金National Natural Science Foundation of China(Nos.E52307038 and U23A20589)Ningbo 2025 Key Scientific Research Programs(Nos.2022Z111,2022Z160 and 2022Z198)the Leading Innovativeand Entrepreneur Team Introduction Program of Zhejiang(No.2021R01005).
文摘The demand for energy-efficient and environmental-friendly power grid construction has made the exploitation of bio-based electrical epoxy resins with excellent properties increasingly important.This work developed the bio-based electrotechnical epoxy resins based on magnolol.High-performance epoxy resin(DGEMT)with a double crosslinked points and its composites(Al_(2)O_(3)/DGEMT)were obtained taking advantages of the two bifunctional groups(allyl and phenolic hydroxyl groups)of magnolol.Benefitting from the distinctive structure of DGEMT,the Al_(2)O_(3)/DGEMT composites exhibited the advantages of intrinsically high thermal conductivity,high insulation,and low dielectric loss.The AC breakdown strength and thermal conductivity of Al_(2)O_(3)/DGEMT composites were 35.5 kV/mm and 1.19 W·m-1·K-1,respectively,which were 15.6%and 52.6%higher than those of petroleum-based composites(Al_(2)O_(3)/DGEBA).And its dielectric loss tanδ=0.0046 was 20.7%lower than that of Al_(2)O_(3)/DGEBA.Furthermore,the mechanical,thermal and processing properties of Al_(2)O_(3)/DGEMT are fully comparable to those of Al_(2)O_(3)/DGEBA.This work confirms the feasibility of manufacturing environmentally friendly power equipment using bio-based epoxy resins,which has excellent engineering applications.
基金supported by the National Natural Science Foundation of China(Nos.51973025 and 52222307)Jilin Science and Technology Bureau(Nos.20220204107YY and 20230204086YY)+1 种基金Changchun Science and Technology Bureau(No.21ZGY06)Jilin Province Development and Reform Commission(No.2023C028-4).
文摘Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ22E030016)the National Natural Science Foundation of China(No.52275137)+1 种基金the China Postdoctoral Science Foundation(No.2022M722831)the Postdoctoral Research Selected Funding Project of Zhejiang Province,China(No.ZJ2022063).
文摘The development of high-performance functional composites has become a research hotspot in response to the hazards of over-heating and electromagnetic radiation in modern electronic devices.Herein,we grew magnetic Fe_(3)O_(4)particles in situ on the MXene layer to obtain an MXene@Fe_(3)O_(4)composite with rich heterogeneous interfaces.Owing to the unique heterostructure and the synergistic effects of multiple electromagnetic wave absorption mechanisms,the composite achieved a minimum reflection loss of-27.14 dB and an effect-ive absorption bandwidth of 2.05 GHz at an absorption thickness of 2 mm.Moreover,the MXene@Fe_(3)O_(4)composite could be encapsu-lated in thermoplastic polyurethane(TPU)via thermal curing.The obtained composite elastomer exhibited a strong tensile strength,and its thermal diffusivity was 113%higher than that of pure TPU.Such additional mechanical properties and thermal conduction features render this composite elastomer an advanced electromagnetic absorber to adapt to the ever-changing environment for expanding practical applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.12322207,12202120 and T2293720/T2293722)the Shenzhen Science and Technology Program,China(Grant No.JCYJ20220531095210022)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2022037)financial support by the National Key Research and Development Program of China(Grant No.2023YFB3812500)。
文摘Liquid crystal elastomers(LCEs)are advanced materials characterized by their rubber-like hyperelasticity and liquid crystal phase transitions,offering exceptional mechanical properties.The development of smart mechanical metamaterials(SMMs)from LCEs expands the potential for controlling mechanical responses and achieving nonlinear behaviors not possible with traditional metamaterials.However,the challenge lies in managing the interplay between nonlinear material responses and structural complexity,making the inverse design of LCE-based SMMs exceptionally demanding.In this paper,we introduce a design framework for LCE smart mechanical metamaterials that leverages neural networks and evolution strategies(ES)to optimize designs with nonlinear mechanical responses.Our approach involves constructing a flexible,unit-cell-based metamaterial model that integrates the soft elastic behavior and thermo-mechanical coupling of LCEs.The combination of microscopic liquid crystal molecule rotation and macroscopic block rotation enables highly tunable and nonlinear mechanical behaviors,of which the precise inverse design of stress-stretch responses is obtained via neural networks combined with ES.In addition,stimuli responses in the liquid crystal elastomers enable real-time adaptability and achieve tailored stress plateaus that are not possible with traditional metamaterials.Our findings provide new pathways in the design and optimization of advanced materials in flexible electronic devices,intelligent actuators,and systems for energy absorption and dissipation.
文摘By investigating the performance characteristics of the bio-based surfactant 8901A,a composite decontamination and injection system was developed using 8901A as the primary agent,tailored for application in low-permeability and heavy oil reservoirs under varying temperature conditions.The results demonstrate that this system effectively reduces oil–water interfacial tension,achieving an ultra-low interfacial tension state.The static oil washing efficiency of oil sands exceeds 85%,the average pressure reduction rate reaches 21.55%,and the oil recovery rate improves by 13.54%.These enhancements significantly increase the system’s ability to dissolve oilbased blockages,thereby lowering water injection pressure caused by organic fouling,increasing the injection volume of injection wells,and ultimately improving oil recovery efficiency.
文摘Purpose–This study aims to carry out optimization and improvement work on the artificial climate aging and ultraviolet aging tests of elastic expansion joints in railway concrete bridges.Design/methodology/approach–Three polyurethane elastomer specimens with different chemical compositions were adopted.According to relevant standard regulations,the aging test process was analyzed and evaluated in detail,and reasonable improvement suggestions were put forward.The effectiveness was verified through actual tests.Findings–The final test results indicate that the combination of artificial climate aging tests and ultraviolet aging tests is technically feasible and has significant advantages in practical applications.Originality/value–This study optimizes the conditions of artificial climate aging and ultraviolet aging tests,compares the advantages and disadvantages of different aging test methods,and proposes a combined test scheme of artificial climate aging and ultraviolet aging and verifies its effectiveness.The results provide valuable reference for simulating the actual aging behavior of polyurethane elastomers,material performance evaluation,and application in railway bridge engineering.It is conducive to promoting the reasonable application of this material in engineering,improving engineering quality,reducing costs,and has economic and social benefits.
基金support from the National Natural Science Foundation of China(Nos.52073017 and 51773009)。
文摘With the rise in environmental awareness,the development of smart polymer materials is gradually becoming environmentally friendly and sustainable.Fluorescent liquid crystal elastomers(LCE)can change their shape or optical properties in response to external stimuli,showing great potential for applications in sensing,information storage,and encryption.However,their life cycle is often unsustainable and not in line with the circular economy model.Based on the principle of green chemistry,a fluorescent LCE was developed through the co-polymerization of multiple monomers with 1,2-dithiolane end groups,which exhibited excellent self-healing,reprocessing,and closed-loop recyclability.In addition,by tailoring the phase transition temperature of the LCE,the transparency and fluorescence intensity of the resulting material can change at a low temperature of 8.0℃.By further integrating light or acid/base-triggered fluorescence information,a proof-of-concept for temperature monitoring during short-time vaccine transportation using the reusable fluorescent LCE film is demonstrated.This study establishes a new environmentally friendly manufacturing strategy for multifunctional LCE materials.
基金financially supported by the National Natural Science Foundation of China(Nos.52275290 and 51905222)the Research Project of the State Key Laboratory of Mechanical System and Oscillation(No.MSV202419)+2 种基金Major Program of the National Natural Science Foundation of China for Basic Theory and Key Technology of Tri-Co Robots(No.92248301)Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University(No.KF2023006)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_2091)。
文摘This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck of precise anisotropic control in LCEs.Mechanically pre-programmed hierarchical LCE structures responsive to near-infrared(NIR)light were fabricated:the oriented constrained actuator achieves asymmetric contraction under NIR irradiation,enabling reversible switching between helix and planar morphologies with multi-terrain grasping capability;the biomimetic vine-like helical actuator,composed of Ag nanowire photothermal layers combined with helical LCE,utilizes temperaturegradient-induced phase transition wave propagation to achieve NIR-controlled climbing motion;the M?bius topology actuator realizes reversible deformation or self-locking states by tuning the twist angle(180°/360°);based on these,a bioinspired koala-like concentric soft robot was constructed,successfully demonstrating tree trunk climbing.This study reveals that artificial helical stretching significantly enhances the molecular chain orientation of LCEs(surpassing uniaxial stretching),reaching up to 1000%pre-strain,and the Ag NWs/LCE/PI(Polyimide)tri-layer structure achieves efficient photothermal-mechanical energy conversion via localized surface plasmon resonance(LSPR).This study provides a new paradigm for soft robotics material design and topological programming,demonstrating the potential for remote operation and adaptive grasping.
文摘Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations and environmental aggressors,silicone elastomers exhibit relatively low stiffness,limiting their direct applicability in seismic isolation.This study investigates the effect of fumed silica as a reinforcing filler to enhance the mechanical properties of laminated silicone elastomeric bearings.Elastomeric samples were fabricated with varying fumed silica proportions and subjected to Shore A hardness,uniaxial tensile,and lap shear tests to assess the influence of filler content.Additionally,quasi-static tests were conducted on reduced-scale bearing prototypes under combined vertical compression and cyclic horizontal shear to evaluate their seismic isolation performance.The results demonstrate that fumed silica reinforcement significantly increases stiffness,as evidenced by higher Shore A hardness values.However,a trade-off was observed in tensile properties,with reductions in tensile strength and elongation at break.Despite this,the equivalent elastic modulus did not show substantial variation up to large deformations,indicating that stiffness is preserved under most working conditions.Lap shear tests showed that fumed silica improves shear resistance,while quasi-static tests revealed inelastic behavior with small increases in equivalent shear coefficients but no substantial loss in damping ratios.These findings suggest that fumed silica reinforcement enhances silicone elastomers’stiffness and shear resistance while maintaining moderate damping properties,making it a promising approach for improving the mechanical performance of elastomeric bearings in seismic isolation applications.
文摘Aging plays a critical role in determining the durability and long-term performance of asphalt pavements,as it is influenced by both external factors(e.g.,temperature,ultraviolet(UV)radiation,moisture,oxidative gases)and internal factors such as binder composition.Although laboratory simulations of aging are well established for conventional bituminous binders,limited attention has been paid to replicating and evaluating aging processes in bio-based binders.This review provides a comprehensive analysis of current laboratory techniques for simulating and assessing binder aging,with a focus on two key areas:aging simulation protocols and evaluation methodologies.The analysis shows that although several efforts have been made to incorporate external aging factors into lab simulations,significant challenges persist,especially in the case of bio-based binders,which are characterized by a high variability in composition and limited understanding of their aging behavior.Current evaluation approaches also exhibit limitations.Improvements are needed in the molecular-level analysis of oxidation(e.g.,through more representative oxidation modelsin molecular dynamicssimulations),in the separation and quantification of binder constituents,and in the application of advanced techniques such as fluorescence microscopy to better characterize polymer dispersion.To enhance the reliability of laboratory simulations,future research should aim to improve the correlation between laboratory and field aging,define robust aging indexes,and refine characterization methods.These advancements are particularly critical for bio-based binders,whose performance is highly sensitive to aging and for which standard test protocols are still underdeveloped.A deeper understanding of aging mechanisms in both polymer-modified and biobased binders,along with improved analytical tools for assessing oxidative degradation and morphological changes,will be essential to support the development of sustainable,high-performance paving materials.
文摘In the context of transitioning toward more sustainable construction materials,this study explores the impact of incorporating millet husks as an alternative to sand on the physical,mechanical,and thermal performance of lightweight concrete.Through a mixture design approach,five formulations were selected and thoroughly characterized.The analysis of iso-response curves enabled an in-depth assessment of the cross-effects between formulation parameters and their interactions on the final properties of the material.The results show that integrating millet husks leads to a significant reduction in density,reaching up to 21%,while maintaining notable mechanical performance.A balanced formulation of sand and fibers achieved a maximum compressive strength of 12.11 MPa,demonstrating that,under specific conditions,plant fibers actively contribute to the structural integrity of the composite.In tensile strength,the positive influence of fibers is even more pronounced,with a maximum resistance of 8.62 MPa,highlighting their role in enhancing material cohesion.From a thermal perspective,millet husks reduce both thermal conductivity and effusivity,thereby limiting heat transfer and accumulation within the composite.Iso-response curve analysis reveals that these effects are directly linked to the proportions of the constituents and that achieving an optimal balance between sand,fibers,and cement is key to maximizing performance.These findings demonstrate that the adopted approach allows moving beyond conventional substitution methods by identifying optimal configurations for the design of lightweight bio-based concretes that are both strong and insulating,thereby confirming the potential of millet husks in developing lightweight concretes suitable for sustainable construction applications.
基金financially supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.20KJA150009)a Project Funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘In recent years,flexible ionic conductors have made remarkable progress in the fields of energy storage devices and flexible sensors.However,most of these materials still face challenges such as the difficult trade-off between stretchability and high mechanical strength,as well as insufficient ionic conductivity.Among them,polymerizable deep eutectic solvents(PDES),which possess both hydrogen bond network construction capabilities and ionic conduction properties,have demonstrated great advantages in the synthesis of flexible ionic conductors.Herein,we report an ionic conductive elastomer(ICE)named PCHS-X based on PDES composed of 2-(methacryloyloxy)-N,N,N-trimethylammonium methyl sulfate(MA-MS),choline chloride(ChCl),and 2-hydroxyethyl acrylate(HEA).The introduction of MA-MS enabled the polymer network to form abundant hydrogen bonds,endowing PCHS-X with excellent mechanical strength,high transparency,favorable ionic conductivity,self-adhesiveness,and self-healing efficiency.When used as a strain sensor,the PCHS-X exhibits highly sensitive strain response,along with good stability and durability,allowing it to accurately monitor the movement of human body parts such as fingers,wrists,elbows,and knees.Additionally,owing to the enhanced ionic mobility at higher temperatures,this material also possesses excellent temperature sensing performance,enabling the fabrication of simple temperature sensors that can sensitively respond to temperature changes.This research provides new strategies for the practical applications of flexible electronic devices in fields such as wearable health monitoring and intelligent human-machine interaction.
文摘An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.
基金Project supported by the National Natural Science Foundation of China(Nos.12125205,12321002,12132014,and 12072316)the Key Research and Development Program of Zhejiang Province of China(No.2021C01183)。
文摘Conventional rotary actuators mainly rely on electric or hydraulic/pneumatic motors to convert energy into mechanical motion,making them one of the most widely used actuation methods in industrial manufacturing,robotics,and automation control.However,these traditional actuators often suffer from limitations in operability and applicability due to their complex structures,bulky systems,high energy consumption,and severe mechanical wear.Liquid crystal elastomers(LCEs)have been increasingly used for programmable actuation applications,owing to their ability to undergo large,reversible,and anisotropic deformations in response to external stimuli.In this work,we propose a compact flexible rotary joint(FRJ)based on LCEs.To describe the thermo-mechanical coupled behaviors,a constitutive model is developed and further implemented for finite element analysis(FEA).Through combining experiments and simulations,we quantify the dynamic rotational behavior of the rotor rotating relative to the base driven by the induced strain of the FRJ under cyclic thermal stimuli.The proposed rotary joint features a simple structure,lightweight design,low energy consumption,and easy control.These characteristics endow it with significant potential for miniaturization and integration in the field of soft actuation and robotics.
