Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinn...Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinning systems that produce such fibers are highly energy efficient,inspiring researchers to mimic these processes to realize robust artificial spinning.Significant developments have been achieved in recent years toward the preparation of high-performance bio-based fibers.Beyond excellent mechanical properties,bio-based fibers can be functionalized with a series of new features,thus expanding their sophisticated applications in smart textiles,electronic sensors,and biomedical engineering.Here,recent progress in the construction of bio-based fibers is outlined.Various bioinspired spinning methods,strengthening strategies for mechanically strong fibers,and the diverse applications of these fibers are discussed.Moreover,challenges in reproducing the mechanical performance of natural systems and understanding their dynamic spinning process are presented.Finally,a perspective on the development of biological fibers is given.展开更多
With growing concerns for global warming and environmental issues,the research community has contributed significantly to green technology in the area of material science through the development of natural fiber-reinf...With growing concerns for global warming and environmental issues,the research community has contributed significantly to green technology in the area of material science through the development of natural fiber-reinforced polymer composites(NFRPC).Polymers serve as the matrix in NFRPC,while natural fibers serve as the reinforcing materials.Demand for high-performing materials made with natural resources is growing continuously.Natural fiber-reinforced polymer composites are sustainable biocomposites fabricated with natural fibers embedded with a polymer matrix.They offer a wide range of advantages,including a low weight-to-strength ratio,high flexural strength,damping properties,and resistance to corrosion,wear,and impact.Understanding the basic properties,characteristics,and processing techniques for natural fibers is important to consider their use as raw materials for high-quality biocomposite.Natural fibers come with low density and a high strengthto-weight ratio,allowing them to be a potential reinforcement for low-weight composites.This article attempts to present a comprehensive review of the available natural fibers,their classification,types,structures,physical properties,characteristics,and mechanical properties.Natural fibers are hydrophilic in nature and require physical and chemical treatment prior to their application as reinforcing material.This review will also cover the required physical and chemical treatments of natural fibers for fabricating biocomposites.展开更多
Novel bio-based and biodegradable block copolymers were synthesized by "click" reaction between poly(L-lactide)(PLLA) and polyamide 4(PA4). Upon tuning the molar mass of PLLA block, the properties of copolym...Novel bio-based and biodegradable block copolymers were synthesized by "click" reaction between poly(L-lactide)(PLLA) and polyamide 4(PA4). Upon tuning the molar mass of PLLA block, the properties of copolymers and electrospun ultrafine fibers were investigated and compared with those of PLLA and PA4 blends. PLLA and PA4 were found incompatible and formed individual crystalline regions, along with reciprocal inhibition in crystallization. Electrospun fibers were highly hydrophobic, even if hydrophilic PA4 was the rich component. The crystallinity of either PLLA or PA4 decreased after electrospinning and PLLA-rich as-spun fibers were almost amorphous. Immersion tests proved that fibers of block copolymers were relatively homogeneous with micro-phase separation between PLLA and PA4. The fibrous structures of copolymers were different from those of the fibers electrospun from blends, for which sheath-core structure induced by macro-phase separation between homopolymers of PLLA and PA4 was confirmed by TEM, EDS, and XPS.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
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
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
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
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
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
The present work is an attempt to develop bio-based hybrid composites by incorporating Betel nut Fiber(BF)and Chicken feather Fiber(CF)at different ratios in modified soybean oil matrix by compression molding techniqu...The present work is an attempt to develop bio-based hybrid composites by incorporating Betel nut Fiber(BF)and Chicken feather Fiber(CF)at different ratios in modified soybean oil matrix by compression molding technique.The ratio of the fiber and resin was taken as 30:70.Epoxidised soybean oil(ESO)was modified by using methacrylic acid and methacrylic anhydride.The ratio of CF and BF was varied from 2:1 to 1:2 respectively.The influence of hybrid fibers and fiber ratio on various properties of the composites was investigated.The obtained results showed that composites prepared with 1:1 ratio of CF and BF exhibited highest tensile strength compared to the other composites prepared by using different ratios of CF and BF.The surface morphology of the composites was studied by Scanning Electron Microscopy(SEM),where surface roughness was found to be decreased after incorporation of hybrid fibers.Thermogravimetric analysis was carried out to study the behaviour of the composites at high temperature,where thermal stability was found to enhance for hybrid composites compared to the composites prepared with single fibers.Also properties like water vapour uptake capacity and volumetric swelling were measured and found to be decreased for the hybrid composites.An overall improvement in properties was observed for composites having 1:1 ratio of CF:BF.Hence,it is concluded that 1:1 weight ratio of CF and BF is the optimum mixing ratio to enhance the various properties of the hybrid composites.展开更多
The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory ...The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory fibers.While the reticulospinal tract has been shown to be particularly prone to axonal growth and plasticity following injuries of the spinal cord,the differential capacities of excitatory and inhibitory fibers for plasticity remain unclear.As adaptive axonal plasticity involves a sophisticated interplay between excitatory and inhibitory input,we investigated in this study the plastic potential of glutamatergic(vGlut2)and GABAergic(vGat)fibers originating from the gigantocellular nucleus and the lateral paragigantocellular nucleus,two nuclei important for locomotor function.Using a combination of viral tracing,chemogenetic silencing,and AI-based kinematic analysis,we investigated plasticity and its impact on functional recovery within the first 3 weeks following injury,a period prone to neuronal remodeling.We demonstrate that,in this time frame,while vGlut2-positive fibers within the gigantocellular and lateral paragigantocellular nuclei rewire significantly following cervical spinal cord injury,vGat-positive fibers are rather unresponsive to injury.We also show that the acute silencing of excitatory axonal fibers which rewire in response to lesions of the spinal cord triggers a worsening of the functional recovery.Using kinematic analysis,we also pinpoint the locomotion features associated with the gigantocellular nucleus or lateral paragigantocellular nucleus during functional recovery.Overall,our study increases the understanding of the role of the gigantocellular and lateral paragigantocellular nuclei during functional recovery following spinal cord injury.展开更多
To develop a suitable production process for fiber reinforced investment casting shell mold,three methods were studied:the traditional method(M_(1)),the method of adding fiber into silica sol with mechanical stirring ...To develop a suitable production process for fiber reinforced investment casting shell mold,three methods were studied:the traditional method(M_(1)),the method of adding fiber into silica sol with mechanical stirring and ultrasonic agitation(M_(2)),and the method of adding fiber into slurry with mechanical stirring and ultrasonic agitation for durations of 3,15,30,and 45 min(M_(3)).The bending strength,high-temperature self-load deformation,and thermal conductivity of the shell molds were investigated.The results reveal that the enhancement of fiber dispersion through ultrasonic agitation improves the comprehensive performance of the shell molds.The maximum green bending strength of the shell mold by M_(2) reaches 3.29 MPa,which is 29% higher than that of the shell mold prepared by M_(1).Moreover,the high-temperature self-load deformation of the shell mold is reduced from 0.62% to 0.44%.In addition,simultaneous ultrasonic agitation and mechanical stirring effectively shorten the slurry preparation time while maintaining comparable levels of fiber dispersion.With the process M_(3)-45 min,the fillers are uniformly dispersed in the slurry,and the fired bending strength and the high-temperature self-load deformation reach 6.25 MPa and 0.41%,respectively.Therefore,the proposed ultrasonic agitation route is promising for the fabrication of fiber-reinforced shell molds with excellent fibers dispersion.展开更多
Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexib...Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexible fiber sensors.Through the preform-tofiber manufacturing technique,a variety of fiber sensors with complex functionalities spanning from the nanoscale to kilometer scale can be automated in a short time.Examples include temperature,acoustic,mechanical,chemical,biological,optoelectronic,and multifunctional sensors,which operate on diverse sensing principles such as resistance,capacitance,piezoelectricity,triboelectricity,photoelectricity,and thermoelectricity.This review outlines the principles of the thermal drawing process and provides a detailed overview of the latest advancements in various thermally drawn fiber sensors.Finally,the future developments of thermally drawn fiber sensors are discussed.展开更多
Variable stiffness composites present a promising solution for mitigating impact loads via varying the fiber volume fraction layer-wise,thereby adjusting the panel's stiffness.Since each layer of the composite may...Variable stiffness composites present a promising solution for mitigating impact loads via varying the fiber volume fraction layer-wise,thereby adjusting the panel's stiffness.Since each layer of the composite may be affected by a different failure mode,the optimal fiber volume fraction to suppress damage initiation and evolution is different across the layers.This research examines how re-allocating the fibers layer-wise enhances the composites'impact resistance.In this study,constant stiffness panels with the same fiber volume fraction throughout the layers are compared to variable stiffness ones by varying volume fraction layer-wise.A method is established that utilizes numerical analysis coupled with optimization techniques to determine the optimal fiber volume fraction in both scenarios.Three different reinforcement fibers(Kevlar,carbon,and glass)embedded in epoxy resin were studied.Panels were manufactured and tested under various loading conditions to validate results.Kevlar reinforcement revealed the highest tensile toughness,followed by carbon and then glass fibers.Varying reinforcement volume fraction significantly influences failure modes.Higher fractions lead to matrix cracking and debonding,while lower fractions result in more fiber breakage.The optimal volume fraction for maximizing fiber breakage energy is around 45%,whereas it is about 90%for matrix cracking and debonding.A drop tower test was used to examine the composite structure's behavior under lowvelocity impact,confirming the superiority of Kevlar-reinforced composites with variable stiffness.Conversely,glass-reinforced composites with constant stiffness revealed the lowest performance with the highest deflection.Across all reinforcement materials,the variable stiffness structure consistently outperformed its constant stiffness counterpart.展开更多
As a potential adsorption material,it is still a challenge for activated carbon fiber(ACF)in efficient adsorption of ethanol due to its nonpolar surface,which is mainly emitted from the grain drying industry.This stud...As a potential adsorption material,it is still a challenge for activated carbon fiber(ACF)in efficient adsorption of ethanol due to its nonpolar surface,which is mainly emitted from the grain drying industry.This study prepared surface polarity-modified ACF using the heteroatom doping method.The modified ACF possessed a richer array of strongly polar oxygen/nitrogen-containing functional groups(primarily phenolic hydroxyl and lactone groups),a larger specific surface are1,and a more developed micropore structure.The adsorption capacities of ethanol for O-ACF and N-ACF were 4.110 mmol/g and 1.698 mmol/g,respectively,which were 11.3 times and 4.7 times those of unmodified ACF.This was a significant improvement over our previous work(0.363 mmol/g).The improvement of adsorption capacity for the N-ACF was mainly due to the higher specific surface are1,greater number of micropores(more adsorption sites)and abundant existence of defects,whereas,for O-ACF,the improvement mainly relied on the abundant presence of oxygen-containing functional groups on the surface.However,water had a negative effect on the adsorption of ethanol for the modified ACF due to competitive adsorption and the disappearance of capillary condensation.It was further revealed that the adsorption process of ethanol and water was quite different.It obeyed the linear driving force(LDF)model for ethanol adsorption,however,the intraparticle diffusion(IPD)model for water adsorption.展开更多
It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranc...It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranched toughener,carboxylic acid-functionalized tannic acid(CATA),was successfully prepared and applicated to the preparation of solvent-free epoxy resins.The mechanical performance,morphology,structural characterization,and thermal characterization of toughened epoxy resin system were studied.The toughened epoxy resin system with only 1.0wt%CATA reached the highest impact strength,111%higher than the neat epoxy resin system.Notably,the tensile strength and elongation at break of toughened epoxy resin systems increased moderately with increasing CATA loading.Nonphase-separated hybrids with significant toughening effect were obtained.Additionally,the thermal stabilities of toughened epoxy resin systems decreased with increasing CATA loading.This study provides an eco-friendly,cost-effective,and facile approach for the preparation of high-performance,solvent-free epoxy resins with potential for practical applications in sealing integrated circuits and electrical devices fields.展开更多
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
In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spect...In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(~1 H-NMR). GSE existed as a potential bio-based reactive diluent for petroleum-based epoxy resin. The curing kinetics of EP/HHPA/GSE system was studied by non-isothermal DSC method. The kinetics parameters were calculated by using the Kissinger model, Crane model, Ozawa model, and β-T(temperature-heating rate) extrapolation, respectively. In addition, the effects of GSE on the thermo-mechanical properties and thermal stability of EP/HHPA/GSE systems were studied, indicating that GSE can effectively improve the toughness and thermal decomposition temperature of the epoxy system.展开更多
基金the National Key Research and Development Program of China(2017YFC1103900)the National Natural Science Foundation of China(22075244 and 51722306)+1 种基金Natural Science Foundation of Zhejiang Province(LZ22E030001)Shanxi-Zheda Institute of Advanced Materials and Chemical Engi-neering(2021SZ-TD009).
文摘Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinning systems that produce such fibers are highly energy efficient,inspiring researchers to mimic these processes to realize robust artificial spinning.Significant developments have been achieved in recent years toward the preparation of high-performance bio-based fibers.Beyond excellent mechanical properties,bio-based fibers can be functionalized with a series of new features,thus expanding their sophisticated applications in smart textiles,electronic sensors,and biomedical engineering.Here,recent progress in the construction of bio-based fibers is outlined.Various bioinspired spinning methods,strengthening strategies for mechanically strong fibers,and the diverse applications of these fibers are discussed.Moreover,challenges in reproducing the mechanical performance of natural systems and understanding their dynamic spinning process are presented.Finally,a perspective on the development of biological fibers is given.
文摘With growing concerns for global warming and environmental issues,the research community has contributed significantly to green technology in the area of material science through the development of natural fiber-reinforced polymer composites(NFRPC).Polymers serve as the matrix in NFRPC,while natural fibers serve as the reinforcing materials.Demand for high-performing materials made with natural resources is growing continuously.Natural fiber-reinforced polymer composites are sustainable biocomposites fabricated with natural fibers embedded with a polymer matrix.They offer a wide range of advantages,including a low weight-to-strength ratio,high flexural strength,damping properties,and resistance to corrosion,wear,and impact.Understanding the basic properties,characteristics,and processing techniques for natural fibers is important to consider their use as raw materials for high-quality biocomposite.Natural fibers come with low density and a high strengthto-weight ratio,allowing them to be a potential reinforcement for low-weight composites.This article attempts to present a comprehensive review of the available natural fibers,their classification,types,structures,physical properties,characteristics,and mechanical properties.Natural fibers are hydrophilic in nature and require physical and chemical treatment prior to their application as reinforcing material.This review will also cover the required physical and chemical treatments of natural fibers for fabricating biocomposites.
基金financially supported by the National Key Research and Development Program of China (Nos. 2017YFB0309301 and 2017YFB0309302)the Natural Science Foundation of Shanghai, China (No. 17ZR1407200)
文摘Novel bio-based and biodegradable block copolymers were synthesized by "click" reaction between poly(L-lactide)(PLLA) and polyamide 4(PA4). Upon tuning the molar mass of PLLA block, the properties of copolymers and electrospun ultrafine fibers were investigated and compared with those of PLLA and PA4 blends. PLLA and PA4 were found incompatible and formed individual crystalline regions, along with reciprocal inhibition in crystallization. Electrospun fibers were highly hydrophobic, even if hydrophilic PA4 was the rich component. The crystallinity of either PLLA or PA4 decreased after electrospinning and PLLA-rich as-spun fibers were almost amorphous. Immersion tests proved that fibers of block copolymers were relatively homogeneous with micro-phase separation between PLLA and PA4. The fibrous structures of copolymers were different from those of the fibers electrospun from blends, for which sheath-core structure induced by macro-phase separation between homopolymers of PLLA and PA4 was confirmed by TEM, EDS, and XPS.
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 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.
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The author,Gitashree Gogoi greatly acknowledged University Grants Commission(UGC),New Delhi,for providing the financial assistance(as fellowship).Grant number-NFO-2018-19-OBC-ASS-75119.
文摘The present work is an attempt to develop bio-based hybrid composites by incorporating Betel nut Fiber(BF)and Chicken feather Fiber(CF)at different ratios in modified soybean oil matrix by compression molding technique.The ratio of the fiber and resin was taken as 30:70.Epoxidised soybean oil(ESO)was modified by using methacrylic acid and methacrylic anhydride.The ratio of CF and BF was varied from 2:1 to 1:2 respectively.The influence of hybrid fibers and fiber ratio on various properties of the composites was investigated.The obtained results showed that composites prepared with 1:1 ratio of CF and BF exhibited highest tensile strength compared to the other composites prepared by using different ratios of CF and BF.The surface morphology of the composites was studied by Scanning Electron Microscopy(SEM),where surface roughness was found to be decreased after incorporation of hybrid fibers.Thermogravimetric analysis was carried out to study the behaviour of the composites at high temperature,where thermal stability was found to enhance for hybrid composites compared to the composites prepared with single fibers.Also properties like water vapour uptake capacity and volumetric swelling were measured and found to be decreased for the hybrid composites.An overall improvement in properties was observed for composites having 1:1 ratio of CF:BF.Hence,it is concluded that 1:1 weight ratio of CF and BF is the optimum mixing ratio to enhance the various properties of the hybrid composites.
基金supported by the Deutsche Forschungsgemeinschaft(DFG),TRR274(Project ID 408885537,Sy Nergy,EXC 2145/ID 390857198,to FMB)。
文摘The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory fibers.While the reticulospinal tract has been shown to be particularly prone to axonal growth and plasticity following injuries of the spinal cord,the differential capacities of excitatory and inhibitory fibers for plasticity remain unclear.As adaptive axonal plasticity involves a sophisticated interplay between excitatory and inhibitory input,we investigated in this study the plastic potential of glutamatergic(vGlut2)and GABAergic(vGat)fibers originating from the gigantocellular nucleus and the lateral paragigantocellular nucleus,two nuclei important for locomotor function.Using a combination of viral tracing,chemogenetic silencing,and AI-based kinematic analysis,we investigated plasticity and its impact on functional recovery within the first 3 weeks following injury,a period prone to neuronal remodeling.We demonstrate that,in this time frame,while vGlut2-positive fibers within the gigantocellular and lateral paragigantocellular nuclei rewire significantly following cervical spinal cord injury,vGat-positive fibers are rather unresponsive to injury.We also show that the acute silencing of excitatory axonal fibers which rewire in response to lesions of the spinal cord triggers a worsening of the functional recovery.Using kinematic analysis,we also pinpoint the locomotion features associated with the gigantocellular nucleus or lateral paragigantocellular nucleus during functional recovery.Overall,our study increases the understanding of the role of the gigantocellular and lateral paragigantocellular nuclei during functional recovery following spinal cord injury.
基金supported by the National Natural Science Foundation of China (Grant No. 5186504)the University Science Foundation for Young Science and Technology Talents in Inner Mongolia Autonomous Region of China (Grant No. NJYT22078)+2 种基金the Basic Scientific Research Expenses Program of Universities directly under Inner Mongolia Autonomous Region (Grant No. JY20220059)the Inner Mongolia Autonomous Region ‘Grassland Talent’ project Young Innovative Talent Training Program Level ⅠBasic Research Expenses of Universities directly under the Inner Mongolia Autonomous Region (Grant No. ZTY2023040)。
文摘To develop a suitable production process for fiber reinforced investment casting shell mold,three methods were studied:the traditional method(M_(1)),the method of adding fiber into silica sol with mechanical stirring and ultrasonic agitation(M_(2)),and the method of adding fiber into slurry with mechanical stirring and ultrasonic agitation for durations of 3,15,30,and 45 min(M_(3)).The bending strength,high-temperature self-load deformation,and thermal conductivity of the shell molds were investigated.The results reveal that the enhancement of fiber dispersion through ultrasonic agitation improves the comprehensive performance of the shell molds.The maximum green bending strength of the shell mold by M_(2) reaches 3.29 MPa,which is 29% higher than that of the shell mold prepared by M_(1).Moreover,the high-temperature self-load deformation of the shell mold is reduced from 0.62% to 0.44%.In addition,simultaneous ultrasonic agitation and mechanical stirring effectively shorten the slurry preparation time while maintaining comparable levels of fiber dispersion.With the process M_(3)-45 min,the fillers are uniformly dispersed in the slurry,and the fired bending strength and the high-temperature self-load deformation reach 6.25 MPa and 0.41%,respectively.Therefore,the proposed ultrasonic agitation route is promising for the fabrication of fiber-reinforced shell molds with excellent fibers dispersion.
基金supported by the National Key Research and Development Program of China(2023YFB3809800)the National Natural Science Foundation of China(52172249,52525601)+2 种基金the Chinese Academy of Sciences Talents Program(E2290701)the Jiangsu Province Talents Program(JSSCRC2023545)the Special Fund Project of Carbon Peaking Carbon Neutrality Science and Technology Innovation of Jiangsu Province(BE2022011).
文摘Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexible fiber sensors.Through the preform-tofiber manufacturing technique,a variety of fiber sensors with complex functionalities spanning from the nanoscale to kilometer scale can be automated in a short time.Examples include temperature,acoustic,mechanical,chemical,biological,optoelectronic,and multifunctional sensors,which operate on diverse sensing principles such as resistance,capacitance,piezoelectricity,triboelectricity,photoelectricity,and thermoelectricity.This review outlines the principles of the thermal drawing process and provides a detailed overview of the latest advancements in various thermally drawn fiber sensors.Finally,the future developments of thermally drawn fiber sensors are discussed.
基金funded by the American University of Sharjah.United Arab Emirates award number EN 9502-FRG19-M-E75。
文摘Variable stiffness composites present a promising solution for mitigating impact loads via varying the fiber volume fraction layer-wise,thereby adjusting the panel's stiffness.Since each layer of the composite may be affected by a different failure mode,the optimal fiber volume fraction to suppress damage initiation and evolution is different across the layers.This research examines how re-allocating the fibers layer-wise enhances the composites'impact resistance.In this study,constant stiffness panels with the same fiber volume fraction throughout the layers are compared to variable stiffness ones by varying volume fraction layer-wise.A method is established that utilizes numerical analysis coupled with optimization techniques to determine the optimal fiber volume fraction in both scenarios.Three different reinforcement fibers(Kevlar,carbon,and glass)embedded in epoxy resin were studied.Panels were manufactured and tested under various loading conditions to validate results.Kevlar reinforcement revealed the highest tensile toughness,followed by carbon and then glass fibers.Varying reinforcement volume fraction significantly influences failure modes.Higher fractions lead to matrix cracking and debonding,while lower fractions result in more fiber breakage.The optimal volume fraction for maximizing fiber breakage energy is around 45%,whereas it is about 90%for matrix cracking and debonding.A drop tower test was used to examine the composite structure's behavior under lowvelocity impact,confirming the superiority of Kevlar-reinforced composites with variable stiffness.Conversely,glass-reinforced composites with constant stiffness revealed the lowest performance with the highest deflection.Across all reinforcement materials,the variable stiffness structure consistently outperformed its constant stiffness counterpart.
基金supported by the National Key R&D Program of China(Nos.2022YFB4101500 and 2022YFE0209500)the National Natural Science Foundation of China(Nos.22276191 and 21976177)the Qinghai Province Air Pollution Assessment and Fine Management Support Project,and the University of Chinese Academy of Science.
文摘As a potential adsorption material,it is still a challenge for activated carbon fiber(ACF)in efficient adsorption of ethanol due to its nonpolar surface,which is mainly emitted from the grain drying industry.This study prepared surface polarity-modified ACF using the heteroatom doping method.The modified ACF possessed a richer array of strongly polar oxygen/nitrogen-containing functional groups(primarily phenolic hydroxyl and lactone groups),a larger specific surface are1,and a more developed micropore structure.The adsorption capacities of ethanol for O-ACF and N-ACF were 4.110 mmol/g and 1.698 mmol/g,respectively,which were 11.3 times and 4.7 times those of unmodified ACF.This was a significant improvement over our previous work(0.363 mmol/g).The improvement of adsorption capacity for the N-ACF was mainly due to the higher specific surface are1,greater number of micropores(more adsorption sites)and abundant existence of defects,whereas,for O-ACF,the improvement mainly relied on the abundant presence of oxygen-containing functional groups on the surface.However,water had a negative effect on the adsorption of ethanol for the modified ACF due to competitive adsorption and the disappearance of capillary condensation.It was further revealed that the adsorption process of ethanol and water was quite different.It obeyed the linear driving force(LDF)model for ethanol adsorption,however,the intraparticle diffusion(IPD)model for water adsorption.
基金from the Special Fund for the Program for Zhejiang Provincial Natural Science Foundation of China(LZ16C160001)National Key Research and Development Program(2017YFD0601105),the National Natural Science Foundation of China(Grant No.21806142)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LY20B070002).
文摘It is essential to design economic and efficient tougheners to prepare high-performance epoxy resin;however,this has remained a huge challenge.Herein,an eco-friendly,low-cost,and facile-fabricated bio-based hyperbranched toughener,carboxylic acid-functionalized tannic acid(CATA),was successfully prepared and applicated to the preparation of solvent-free epoxy resins.The mechanical performance,morphology,structural characterization,and thermal characterization of toughened epoxy resin system were studied.The toughened epoxy resin system with only 1.0wt%CATA reached the highest impact strength,111%higher than the neat epoxy resin system.Notably,the tensile strength and elongation at break of toughened epoxy resin systems increased moderately with increasing CATA loading.Nonphase-separated hybrids with significant toughening effect were obtained.Additionally,the thermal stabilities of toughened epoxy resin systems decreased with increasing CATA loading.This study provides an eco-friendly,cost-effective,and facile approach for the preparation of high-performance,solvent-free epoxy resins with potential for practical applications in sealing integrated circuits and electrical devices fields.
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.
基金the financial support provided by "One Hundred Talented People" of the Chinese Academy of Sciences–China (No. Y60707WR04)Natural Science Foundation of Zhejiang Province (No. Y16B040008)
文摘In this study, monoglycidyl silyl etherated eugenol(GSE) was synthesized as reactive epoxy diluent, and the chemical structure of GSE, intermediates, and products were characterized by Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(~1 H-NMR). GSE existed as a potential bio-based reactive diluent for petroleum-based epoxy resin. The curing kinetics of EP/HHPA/GSE system was studied by non-isothermal DSC method. The kinetics parameters were calculated by using the Kissinger model, Crane model, Ozawa model, and β-T(temperature-heating rate) extrapolation, respectively. In addition, the effects of GSE on the thermo-mechanical properties and thermal stability of EP/HHPA/GSE systems were studied, indicating that GSE can effectively improve the toughness and thermal decomposition temperature of the epoxy system.
