One novel two-dimensional(2D)terbium-based framework[Tb(L2-)(Ac)(DMA)]n(1)(H2 L=4’-(3,5-dicarboxyphenyl)-4,2’:6’,4"-terpyridine)was successfully isolated and structurally characterized.The structural analysis ...One novel two-dimensional(2D)terbium-based framework[Tb(L2-)(Ac)(DMA)]n(1)(H2 L=4’-(3,5-dicarboxyphenyl)-4,2’:6’,4"-terpyridine)was successfully isolated and structurally characterized.The structural analysis reveals that two Tb3+ions in 1 are bridged by twoη1:η1:μ2 carboxylates from L2-to form a binuclear unit,which is further linked by L2-to generate a 2D layer with kgd topology.Moreover,1 displays excellent thermostability and extensive solvent stability.Luminescent measurements reveal that 1 can be used as a recyclable luminescent probe for detecting pyridine with the lowest detection lim it of 0.12 vol%,and the luminescent mechanism is also discussed.展开更多
Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste.In this work,a dynamic cross-linked polyimide insulation film wit...Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste.In this work,a dynamic cross-linked polyimide insulation film with full closed-loop recyclability is successfully prepared,which also possesses good self-healing ability after being mechanical/electrical damaged depending on the Schiff base dynamic covalent bonds.The recycled and self-healed polyimide film still maintain its good tensile strength(r t)>60 MPa with Young’s modulus(E)>4 GPa,high thermal stability with glass transition temperature(T g)>220℃,and outstanding insulation property with breakdown strength(E 0)>358 kV mm^(-1),making it a very promising low energy consumption and high temperature resistant insulation material.The strategy of using Schiff base dynamic covalent bonds for reversible repairing the structure of high T g polyimides promotes the wider application of such sustainable and recyclable material in the field of electrical power and micro-electronics.展开更多
Physical cross-linking by hydrogen-bonds (H-bonds), providing a good combination of application properties of thermosets and processability of thermoplastics, is a potential strategy to resolve the recycling problem o...Physical cross-linking by hydrogen-bonds (H-bonds), providing a good combination of application properties of thermosets and processability of thermoplastics, is a potential strategy to resolve the recycling problem of traditional chemically cross-linked polyethylene. However, ureidopyrimidone (UPy), the most widely used H-bonding motif, is unfavorable for large-scale industrial application due to its poor thermal stability. In this work, H-bonds cross-linked polyethylene was successfully prepared by reactive melt blending maleic anhydride grafted polyethylene (PE-g-MAH) with 3-amino-1,2,4-triazole (ATA) to form amide triazole ring-carboxylic acid units. Triazole ring can easily generate multiple H-bonds with carboxylic acid and amide. More importantly, these units are more thermal stable than UPy due to the absence of unstable urea group of UPy. The introduction of H-bonds cross-linking leads to an obvious improvement in mechanical properties and creep resistance and a good maintain in thermal properties and recyclability. Furthermore, the reinforcement effect monotonically improves with increasing the density of H-bonds. The obtained good properties are mainly attributed to largely enhanced interchain interactions induced by H-bonds cross-linking and intrinsic reversibility of H-bonds. This work develops a novel way for the simple fabrication of H-bonds cross-linked PE with high performance through reactive melt blending.展开更多
In order to extend the application of epoxy vitrimer, 1,4-cyclohexanedicarboxylic acid（CHDA） was used as a co-curing agent and structure modifier for sebacic acid（SA） cured diglycidyl ether of bisphenol A（DGEBA）...In order to extend the application of epoxy vitrimer, 1,4-cyclohexanedicarboxylic acid（CHDA） was used as a co-curing agent and structure modifier for sebacic acid（SA） cured diglycidyl ether of bisphenol A（DGEBA） epoxy vitrimer to tailor the mechanical properties of epoxy vitrimers with 1,5,7-triazabicylo[4.4.0]dec-5-ene（TBD） as a transesterification catalyst. The glass transition temperature（Tg） of vitrimer increased gradually with the increase in CHDA content. Vitrimers behaved from elastomer to tough and hard plastics were successfully achieved by varying the feed ratio of CHDA to SA. Both the Young＇s modulus and storage modulus increased apparently with the increase in CHDA content. Stress relaxation measurement indicated that more prominent stress relaxation occurred at elevated temperatures and the stress relaxation decreased with the increase of CHDA content due to the reduced mobility of the vitrimer backbone. The vitrimers showed excellent recyclability as evidenced by the unchanged gel fraction and mechanical properties after compression molded for several times. With tunable mechanical properties, the epoxy vitrimers may find extensive potential applications.展开更多
Phase change materials(PCMs) present promising potential for guaranteeing safety in thermal management systems.However,most reported PCMs have a single application in energy storage for thermal management systems,whic...Phase change materials(PCMs) present promising potential for guaranteeing safety in thermal management systems.However,most reported PCMs have a single application in energy storage for thermal management systems,which does not meet the growing demand for multi-functional materials.In this paper,the flexible material and hydrogen-bonding function are innovatively combined to design and prepare a novel multi-functional flexible phase change film(PPL).The 0.2PPL-2 film exhibits solid-solid phase change behavior with energy storage density of 131.8 J/g at the transition temperature of42.1℃,thermal cycling stability(500 cycles),wide-temperature range flexibility(0-60℃) and selfhealing property.Notably,the PPL film can be recycled up to 98.5% by intrinsic remodeling.Moreover,the PPL film can be tailored to the desired colors and configurations and can be cleverly assembled on several thermal management systems at ambient temperature through its flexibility combined with shape-memory properties.More interestingly,the transmittance of PPL will be altered when the ambient temperature changes(60℃),conveying a clear thermal signal.Finally,the thermal energy storage performance of the PPL film is successfully tested by human thermotherapy and electronic device temperature control experiments.The proposed functional integration strategy provides innovative ideas to design PCMs for multifunctionality,and makes significant contributions in green chemistry,highefficiency thermal management,and energy sustainability.展开更多
In this paper,we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activa...In this paper,we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activated carbon and also to recycle the water used in dialysis.We studied the adsorption of artificial waste dialysate,which is a mixed solution of urea,creatinine,and uric acid,and the separate solutions for each of these and found that their extents of adsorption onto the spherical activated carbon material were nearly identical.The amount of adsorption was approximately 1.4 mg·g^−1 for urea,18 mg·g^−1 for creatinine,and 20 mg·g^−1 for uric acid.The urea,creatinine,and uric acid adsorbed onto the spherical activated carbon decomposed on heat treatment at 500℃,and the adsorption capacity of the spherical activated carbon was regenerated.Our study successfully demonstrated that the spherical activated carbon can be recycled in the waste dialysate treatment process.展开更多
Now, a rapidly growing concern for the environmental protection and resource utilization has stimulated many new activities in the in dustrialized world for coping with urgent environmental problems created by the ste...Now, a rapidly growing concern for the environmental protection and resource utilization has stimulated many new activities in the in dustrialized world for coping with urgent environmental problems created by the steadily increasing consumption of industrial products. Increasingly stringent r egulations and widely expressed public concern for the environment highlight the importance of disposing solid waste generated from industrial and consumable pr oducts. How to efficiently recycle and tackle this problem has been a very impo rtant issue over the world. Designing products for recyclability is driven by environmental and economic goals. To obtain good recyclability, two measures can be adopted. One is better recycling strategy and technology; the other is design for recycling (DFR). The recycling strategies of products generally inclu de: reuse, service, remanufacturing, recycling of production scraps during the p roduct usage, recycle (separation first) and disposal. Recyclability assessment is a very important content in DFR. This paper first discusses the content of D FR and strategies and types related to products recyclability, and points out th at easy or difficult recyclability depends on the design phase. Then method and procedure of recyclability assessment based on ANN is explored in detail. The pr ocess consists of selection of the ANN input and output parameters, control of t he sample quality and construction and training of the neural network. At la st, the case study shows this method is simple and operative.展开更多
We present a ring-opening polymerization of bridged cyclic lactone utilizing alcohol as the initiator and organic base as the catalyst.Bridged γ-butyrolactone monomers(PhSGBL and PhSeGBL)were synthesized efficiently ...We present a ring-opening polymerization of bridged cyclic lactone utilizing alcohol as the initiator and organic base as the catalyst.Bridged γ-butyrolactone monomers(PhSGBL and PhSeGBL)were synthesized efficiently from commercially available 3-cyclohexene-1-carboxylic acid.Due to the ring strain of the bridged structure,ring-opening polymerization of this type of γ-butyrolactone derivative was successfully carried out under mild conditions,e.g.,using ethylene glycol as the initiator and a commercial catalyst[1,5,7-triazabicyclo[4.4.0 dec-5-ene(TBD)]]as the catalyst at 30℃.The obtained polymer could be degraded to its monomer for recycling in the presence of ZnCl_(2) as a catalyst.PhSGBL and PhSeGBL could also be copolymerized with ε-caprolactone to tune the glass transition temperature.Additionally,the hydrophilicity of the obtained sulfur-containing polymers could be adjusted by selectively oxidizing the thioether side group to sulfone/sulfoxide,which offered a way to tune the hydrophilicity of polyester.On the other hand,the obtained selenium-containing compound could be degraded in the presence of m-CPBA(3-chloroperbenzoic acid),which offered potential application in sustained drug release.展开更多
The molecular recyclability of poly (ethylene terephthalate) (PET) and three semi-aromatic polyesters poly (phloretic acid) (poly-H), poly (dihydroferulic acid) (poly-G), and poly (dihydrosinapinic acid) (poly-S) is e...The molecular recyclability of poly (ethylene terephthalate) (PET) and three semi-aromatic polyesters poly (phloretic acid) (poly-H), poly (dihydroferulic acid) (poly-G), and poly (dihydrosinapinic acid) (poly-S) is evaluated in this study. PET is an extensively used aromatic polyester, and poly-H, poly-G, and poly-S can be considered semi-aromatic poly (lactic acid) modifications. All these polyesters have been depolymerized at neutral pH and by acid- and base-catalyzed hydrolysis at two temperatures, i.e., 50˚C and 80˚C. Base-catalyzed depolymerization of virgin PET leads to an isolated yield of 38% after 48 hours of reaction at 80˚C. Contrary to these results for PET, almost all the monomers of the semi-aromatic polyesters poly-H, poly-G, and poly-S are recovered with isolated yields larger than 90% at the same temperature after 15 minutes in a facile manner. A shrinking particle model used to determine the global kinetics of the base-catalyzed depolymerization showed that the rate rises with increasing temperature. Using the shrinking particle model, the intrinsic reaction rate constants were determined. It has been demonstrated that the rate coefficients of the depolymerization of the semi-aromatic polyesters poly-H, poly-G, and poly-S are between 2 and 3 orders of magnitude higher than those for PET.展开更多
Recently,the focus of materials research has shifted toward intelligent materials and structures with customizable properties and stimulus-responsive functions.Here,a recyclable thermosetting epoxy resin with self-rep...Recently,the focus of materials research has shifted toward intelligent materials and structures with customizable properties and stimulus-responsive functions.Here,a recyclable thermosetting epoxy resin with self-reported wear and customizable friction is achieved through dynamic and reversible molecular structure design.The epoxy vitrimer displays exceptional mechanical properties,with a Young's modulus of 2.3 GPa,elongation at break of 7.1%,and tensile strength of 79.25 MPa.Based on the reversible exchange of dynamic covalent bonds,the epoxy vitrimer can be fully recovered through hot pressing without the need for additional adhesives or catalysts,and even self-healing can be achieved.Furthermore,by utilizing the reversibility of dynamic covalent bonds,nanofillers(graphene oxide(GO)and polytetrafluoroethylene(PTFE))with specific tribological properties are incorporated into the recovery process to achieve customizable friction coefficients and wear rates.The self-reported characteristics of wear based on sulfur radicals are realized by exploiting the dynamic nature of disulfide bonds.The correlation between wear time and wear state is investigated.The molecular structure design of epoxy based on dynamic covalent bonds has resulted in a versatile thermosetting material with self-reporting and customizable friction properties that is ideal for sustainable engineering and friction applications.This enables intelligent manufacturing while reducing resource waste.展开更多
The industrial application of nano-photocatalysts in wastewater treatment has been severely restricted for a long time due to their difficult separation,poor reusability,and low efficiency.In this work,a facile strate...The industrial application of nano-photocatalysts in wastewater treatment has been severely restricted for a long time due to their difficult separation,poor reusability,and low efficiency.In this work,a facile strategy was proposed to enhance the photocatalytic activity and recovery performance of Ag@AgCl nanocatalysts.Biological veins(Bio-veins)with a unique 3D porous construction were used as carriers for the in-situ growth of Ag@AgCl nanoparticles.Scanning electron microscopy results showed that the Ag@AgCl nanoparticles were uniformly loaded on the surface and interior of the Bio-veins,and the size of the Ag@AgCl nanoparticles immobilized on the Bio-veins(50–300 nm)was significantly smaller than Ag@AgCl obtained by the co-precipitation method(1–3μm).The Bio-veins played a vital role in the photocatalysis reaction system.The degradation efficiency of the Ag@AgCl/Bio-veins(CI4)was up to 3.50 times as high as pure Ag@AgCl.Furthermore,the composites also exhibited excellent recyclability and stability under both visible and solar light.This work provided a suitable strategy for nano-photocatalysts for practical application and may also offer new possibilities for the high-value utilization of biomass materials.展开更多
With the start of the new year,Wen Congxiang,managing director of Ningbo Nuoding,a company specialising in the recycling of end-of-life vehicles,has been constantly on the move.Much of his time is spent coordinating w...With the start of the new year,Wen Congxiang,managing director of Ningbo Nuoding,a company specialising in the recycling of end-of-life vehicles,has been constantly on the move.Much of his time is spent coordinating with vehicle collection firms,electric bicycle manufacturers and recycled materials distributors,as he works to build partnerships focused on the targeted collection and distribution of recycled products.展开更多
Conventional thermosetting polymers,mostly derived from nonrenewable petroleum resources,are not reprocessable and recyclable due to their highly cross-linked three-dimensional networks and face the disadvantage of hi...Conventional thermosetting polymers,mostly derived from nonrenewable petroleum resources,are not reprocessable and recyclable due to their highly cross-linked three-dimensional networks and face the disadvantage of high flammability.To solve these issues,in this study,we synthesized a novel Schiff base covalent adaptable thermoset from a furan-derived tri-aldehyde monomer(TMFP)and a furan-derived di-amine monomer(DFDA).The as-prepared TMFP-DFDA-Vitrimer exhibited superior anti-flammability with a high limiting oxygen index(LOI)of 35.0%and a UL-94 V-0 rating,which was attributed to the excellent charring ability.Additionally,TMFPDFDA-Vitrimer could also be conveniently recycled by chemical decomposition under a mixed hydrochloric acid/tetrahydrofuran(HCl/THF)solution.After recycling for 5 times,the thermal,mechanical,and flame retardant properties of the recycled TMFP-DFDA-Vitrimer retained almost unchanged compared to the original one.This work provides a prime instance to develop advanced thermosetting polymers from abundant furan-based compounds.展开更多
Recycling spent lithium-ion(Li+)batteries is critical for achieving environmental conservation and the strategic recovery of essential resources.Compared with conventional methods for recovering cathode materials,whic...Recycling spent lithium-ion(Li+)batteries is critical for achieving environmental conservation and the strategic recovery of essential resources.Compared with conventional methods for recovering cathode materials,which are energy-intensive and prone to secondary pollution,the direct regeneration approach has emerged as a rapid and highly efficient method,gaining widespread attention in recent years.However,this approach faces major challenges,including degraded electrochemical performances and limited economic value.This study,therefore,proposes a high-value direct regeneration strategy to convert degraded spent LiFePO_(4)(S-LFP)into a gradient manganese(Mn)-doped regenerated LiFe_(0.7)Mn_(0.3)PO_(4)/C(R-LFMP)composite.This method leverages the inherent microcracks and Li vacancies present in S-LFP,likely acting as diffusion channels for the Mn^(2+)/Li^(+)ions.Through a two-step mechanochemical ball-milling and carbothermal reduction process,this approach achieves simultaneous Li replenishment and surface-localised Mn gradient doping with enhanced structural control.Notably,the R-LFMP exhibits an exceptional electrochemical performance.At 0.1 C,it delivers a discharge capacity of 161.4 mA h g^(−1)and an energy density of 563.5 Wh kg^(−1)(representing a 60.5%improvement over S-LFP).Additionally,it maintains 83%capacity retention after 900 cycles at 0.5C,a considerable enhancement compared to commercial LFMP(62%).Furthermore,the regenerated cathode material generates a net profit of$7.102 kg^(−1),surpassing the profitability of conventional recycling methods by 90%.Overall,this study introduces a transformative and sustainable LFP regeneration technology,achieving breakthroughs in electrochemical restoration and high-value recycling,while paving the way for the closed-loop utilisation of LFP-based energy storage systems.展开更多
This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw ...This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw resistance and durability of recycled concrete samples under varying freeze-thaw cycles.The results indicate that an appropriate addition of SAP significantly enhances the freeze-thaw resistance of recycled concrete.After 200 freeze-thaw cycles,the RS0.6 sample retained good surface integrity,demonstrating the best performance.Compared to NAC,its mass loss decreased by 1.16%,the relative dynamic modulus improved by 7.01%,and the compressive strength loss rate decreased by 5.41%.Additionally,T2 spectrum analysis revealed that adding SAP optimized the pore structure of recycled concrete and mitigated pore development during freeze-thaw cycles.As the number of freeze-thaw cycles increased,the RS0.3 and RS0.6 samples demonstrated superior frost resistance compared to NAC.However,an excessive amount of SAP increased pore expansion during subsequent freeze-thaw cycles,ultimately weakening frost resistance.展开更多
Europe is grappling with a colossal textile waste problem.Over 125 million tonnes of raw materials are devoured by the global industry each year,yet a mere fraction-less than 1%-of these fibres originate from recycled...Europe is grappling with a colossal textile waste problem.Over 125 million tonnes of raw materials are devoured by the global industry each year,yet a mere fraction-less than 1%-of these fibres originate from recycled textiles.The majority faces an unsustainable fate in landfills,incinerators,or is exported.A pivotal new report by Systemiq,"The Textile Recycling Breakthrough,"offers both a stark assessment and a strategic roadmap:Europe has the potential to amplify polyester textile recycling nearly tenfold by 2035,but this hinges on immediate,decisive action from policymakers and the industry.展开更多
Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of me...Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.展开更多
We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-gener...We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.展开更多
PKU:The super fibers combine strength and toughness In impact protection applications such as ballistic armor,vehicle shielding,and aerospace,the dynamic strength and dynamic toughness of fiber materials are critical ...PKU:The super fibers combine strength and toughness In impact protection applications such as ballistic armor,vehicle shielding,and aerospace,the dynamic strength and dynamic toughness of fiber materials are critical performance indicators determining protective efficacy.However,widely used polymeric fibers still face significant challenges preventing full utilization of the material’s intrinsic strength and toughness.展开更多
Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of re...Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.展开更多
基金Project supported by National Natural Science Foundation of China(21701039)Natural Science Foundation of Hebei Province(B2017201055)+1 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(201002099)the Fund for Shanxi"1331 Project"Key Innovative Research Team。
文摘One novel two-dimensional(2D)terbium-based framework[Tb(L2-)(Ac)(DMA)]n(1)(H2 L=4’-(3,5-dicarboxyphenyl)-4,2’:6’,4"-terpyridine)was successfully isolated and structurally characterized.The structural analysis reveals that two Tb3+ions in 1 are bridged by twoη1:η1:μ2 carboxylates from L2-to form a binuclear unit,which is further linked by L2-to generate a 2D layer with kgd topology.Moreover,1 displays excellent thermostability and extensive solvent stability.Luminescent measurements reveal that 1 can be used as a recyclable luminescent probe for detecting pyridine with the lowest detection lim it of 0.12 vol%,and the luminescent mechanism is also discussed.
基金This work was financially supported by the National Natural Science Foundation of China (No.51977114,52177020)Fundamental Research Funds for the Central Universities (No.FRF-NP-19-008 and FRF-TP-20-02B2)Scientific and Techno-logical Innovation Foundation of Foshan (BK21BE006).
文摘Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste.In this work,a dynamic cross-linked polyimide insulation film with full closed-loop recyclability is successfully prepared,which also possesses good self-healing ability after being mechanical/electrical damaged depending on the Schiff base dynamic covalent bonds.The recycled and self-healed polyimide film still maintain its good tensile strength(r t)>60 MPa with Young’s modulus(E)>4 GPa,high thermal stability with glass transition temperature(T g)>220℃,and outstanding insulation property with breakdown strength(E 0)>358 kV mm^(-1),making it a very promising low energy consumption and high temperature resistant insulation material.The strategy of using Schiff base dynamic covalent bonds for reversible repairing the structure of high T g polyimides promotes the wider application of such sustainable and recyclable material in the field of electrical power and micro-electronics.
基金financially supported by the National Natural Science Foundation of China (No. 51803130)Fundamental Research Funds for Central UniversitiesChongqing University Key Laboratory of Micro/Nano Materials Engineering and Technology (No. KFJJ2005)
文摘Physical cross-linking by hydrogen-bonds (H-bonds), providing a good combination of application properties of thermosets and processability of thermoplastics, is a potential strategy to resolve the recycling problem of traditional chemically cross-linked polyethylene. However, ureidopyrimidone (UPy), the most widely used H-bonding motif, is unfavorable for large-scale industrial application due to its poor thermal stability. In this work, H-bonds cross-linked polyethylene was successfully prepared by reactive melt blending maleic anhydride grafted polyethylene (PE-g-MAH) with 3-amino-1,2,4-triazole (ATA) to form amide triazole ring-carboxylic acid units. Triazole ring can easily generate multiple H-bonds with carboxylic acid and amide. More importantly, these units are more thermal stable than UPy due to the absence of unstable urea group of UPy. The introduction of H-bonds cross-linking leads to an obvious improvement in mechanical properties and creep resistance and a good maintain in thermal properties and recyclability. Furthermore, the reinforcement effect monotonically improves with increasing the density of H-bonds. The obtained good properties are mainly attributed to largely enhanced interchain interactions induced by H-bonds cross-linking and intrinsic reversibility of H-bonds. This work develops a novel way for the simple fabrication of H-bonds cross-linked PE with high performance through reactive melt blending.
基金financially supported by the National Natural Science Foundation of China (No.51703188)Fundamental Research Funds for the Central Universities (Nos.XDJK2017A016 and XDJK2017C022)
文摘In order to extend the application of epoxy vitrimer, 1,4-cyclohexanedicarboxylic acid（CHDA） was used as a co-curing agent and structure modifier for sebacic acid（SA） cured diglycidyl ether of bisphenol A（DGEBA） epoxy vitrimer to tailor the mechanical properties of epoxy vitrimers with 1,5,7-triazabicylo[4.4.0]dec-5-ene（TBD） as a transesterification catalyst. The glass transition temperature（Tg） of vitrimer increased gradually with the increase in CHDA content. Vitrimers behaved from elastomer to tough and hard plastics were successfully achieved by varying the feed ratio of CHDA to SA. Both the Young＇s modulus and storage modulus increased apparently with the increase in CHDA content. Stress relaxation measurement indicated that more prominent stress relaxation occurred at elevated temperatures and the stress relaxation decreased with the increase of CHDA content due to the reduced mobility of the vitrimer backbone. The vitrimers showed excellent recyclability as evidenced by the unchanged gel fraction and mechanical properties after compression molded for several times. With tunable mechanical properties, the epoxy vitrimers may find extensive potential applications.
基金supported by the Project of Shanghai Science and Technology Commission (Grant No. 19DZ1203102)National Key Research and Development Project (2018YFD0401300)Shanghai Municipal Science and Technology Project (16040501600)。
文摘Phase change materials(PCMs) present promising potential for guaranteeing safety in thermal management systems.However,most reported PCMs have a single application in energy storage for thermal management systems,which does not meet the growing demand for multi-functional materials.In this paper,the flexible material and hydrogen-bonding function are innovatively combined to design and prepare a novel multi-functional flexible phase change film(PPL).The 0.2PPL-2 film exhibits solid-solid phase change behavior with energy storage density of 131.8 J/g at the transition temperature of42.1℃,thermal cycling stability(500 cycles),wide-temperature range flexibility(0-60℃) and selfhealing property.Notably,the PPL film can be recycled up to 98.5% by intrinsic remodeling.Moreover,the PPL film can be tailored to the desired colors and configurations and can be cleverly assembled on several thermal management systems at ambient temperature through its flexibility combined with shape-memory properties.More interestingly,the transmittance of PPL will be altered when the ambient temperature changes(60℃),conveying a clear thermal signal.Finally,the thermal energy storage performance of the PPL film is successfully tested by human thermotherapy and electronic device temperature control experiments.The proposed functional integration strategy provides innovative ideas to design PCMs for multifunctionality,and makes significant contributions in green chemistry,highefficiency thermal management,and energy sustainability.
文摘In this paper,we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activated carbon and also to recycle the water used in dialysis.We studied the adsorption of artificial waste dialysate,which is a mixed solution of urea,creatinine,and uric acid,and the separate solutions for each of these and found that their extents of adsorption onto the spherical activated carbon material were nearly identical.The amount of adsorption was approximately 1.4 mg·g^−1 for urea,18 mg·g^−1 for creatinine,and 20 mg·g^−1 for uric acid.The urea,creatinine,and uric acid adsorbed onto the spherical activated carbon decomposed on heat treatment at 500℃,and the adsorption capacity of the spherical activated carbon was regenerated.Our study successfully demonstrated that the spherical activated carbon can be recycled in the waste dialysate treatment process.
文摘Now, a rapidly growing concern for the environmental protection and resource utilization has stimulated many new activities in the in dustrialized world for coping with urgent environmental problems created by the steadily increasing consumption of industrial products. Increasingly stringent r egulations and widely expressed public concern for the environment highlight the importance of disposing solid waste generated from industrial and consumable pr oducts. How to efficiently recycle and tackle this problem has been a very impo rtant issue over the world. Designing products for recyclability is driven by environmental and economic goals. To obtain good recyclability, two measures can be adopted. One is better recycling strategy and technology; the other is design for recycling (DFR). The recycling strategies of products generally inclu de: reuse, service, remanufacturing, recycling of production scraps during the p roduct usage, recycle (separation first) and disposal. Recyclability assessment is a very important content in DFR. This paper first discusses the content of D FR and strategies and types related to products recyclability, and points out th at easy or difficult recyclability depends on the design phase. Then method and procedure of recyclability assessment based on ANN is explored in detail. The pr ocess consists of selection of the ANN input and output parameters, control of t he sample quality and construction and training of the neural network. At la st, the case study shows this method is simple and operative.
基金financially supported by National Key Research and Development Program of China(No.2022YFB3704905)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘We present a ring-opening polymerization of bridged cyclic lactone utilizing alcohol as the initiator and organic base as the catalyst.Bridged γ-butyrolactone monomers(PhSGBL and PhSeGBL)were synthesized efficiently from commercially available 3-cyclohexene-1-carboxylic acid.Due to the ring strain of the bridged structure,ring-opening polymerization of this type of γ-butyrolactone derivative was successfully carried out under mild conditions,e.g.,using ethylene glycol as the initiator and a commercial catalyst[1,5,7-triazabicyclo[4.4.0 dec-5-ene(TBD)]]as the catalyst at 30℃.The obtained polymer could be degraded to its monomer for recycling in the presence of ZnCl_(2) as a catalyst.PhSGBL and PhSeGBL could also be copolymerized with ε-caprolactone to tune the glass transition temperature.Additionally,the hydrophilicity of the obtained sulfur-containing polymers could be adjusted by selectively oxidizing the thioether side group to sulfone/sulfoxide,which offered a way to tune the hydrophilicity of polyester.On the other hand,the obtained selenium-containing compound could be degraded in the presence of m-CPBA(3-chloroperbenzoic acid),which offered potential application in sustained drug release.
文摘The molecular recyclability of poly (ethylene terephthalate) (PET) and three semi-aromatic polyesters poly (phloretic acid) (poly-H), poly (dihydroferulic acid) (poly-G), and poly (dihydrosinapinic acid) (poly-S) is evaluated in this study. PET is an extensively used aromatic polyester, and poly-H, poly-G, and poly-S can be considered semi-aromatic poly (lactic acid) modifications. All these polyesters have been depolymerized at neutral pH and by acid- and base-catalyzed hydrolysis at two temperatures, i.e., 50˚C and 80˚C. Base-catalyzed depolymerization of virgin PET leads to an isolated yield of 38% after 48 hours of reaction at 80˚C. Contrary to these results for PET, almost all the monomers of the semi-aromatic polyesters poly-H, poly-G, and poly-S are recovered with isolated yields larger than 90% at the same temperature after 15 minutes in a facile manner. A shrinking particle model used to determine the global kinetics of the base-catalyzed depolymerization showed that the rate rises with increasing temperature. Using the shrinking particle model, the intrinsic reaction rate constants were determined. It has been demonstrated that the rate coefficients of the depolymerization of the semi-aromatic polyesters poly-H, poly-G, and poly-S are between 2 and 3 orders of magnitude higher than those for PET.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB 0470303)the National Natural Science Foundation of China(No.52305225 and 51935012)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(No.YSBR-023).
文摘Recently,the focus of materials research has shifted toward intelligent materials and structures with customizable properties and stimulus-responsive functions.Here,a recyclable thermosetting epoxy resin with self-reported wear and customizable friction is achieved through dynamic and reversible molecular structure design.The epoxy vitrimer displays exceptional mechanical properties,with a Young's modulus of 2.3 GPa,elongation at break of 7.1%,and tensile strength of 79.25 MPa.Based on the reversible exchange of dynamic covalent bonds,the epoxy vitrimer can be fully recovered through hot pressing without the need for additional adhesives or catalysts,and even self-healing can be achieved.Furthermore,by utilizing the reversibility of dynamic covalent bonds,nanofillers(graphene oxide(GO)and polytetrafluoroethylene(PTFE))with specific tribological properties are incorporated into the recovery process to achieve customizable friction coefficients and wear rates.The self-reported characteristics of wear based on sulfur radicals are realized by exploiting the dynamic nature of disulfide bonds.The correlation between wear time and wear state is investigated.The molecular structure design of epoxy based on dynamic covalent bonds has resulted in a versatile thermosetting material with self-reporting and customizable friction properties that is ideal for sustainable engineering and friction applications.This enables intelligent manufacturing while reducing resource waste.
基金This work was supported by the National Natural Science Foundation of China(Grant No.21776067)the Outstanding Youth Foundation of Hunan Province(Grant No.2020JJ2014)+1 种基金the Natural Science Foundation of Hunan Province(Grant Nos.2022JJ30264,2020JJ5159)the Scientific Research Fund of Hunan Provincial Education Department(Grant Nos.20C0803,21B0476).
文摘The industrial application of nano-photocatalysts in wastewater treatment has been severely restricted for a long time due to their difficult separation,poor reusability,and low efficiency.In this work,a facile strategy was proposed to enhance the photocatalytic activity and recovery performance of Ag@AgCl nanocatalysts.Biological veins(Bio-veins)with a unique 3D porous construction were used as carriers for the in-situ growth of Ag@AgCl nanoparticles.Scanning electron microscopy results showed that the Ag@AgCl nanoparticles were uniformly loaded on the surface and interior of the Bio-veins,and the size of the Ag@AgCl nanoparticles immobilized on the Bio-veins(50–300 nm)was significantly smaller than Ag@AgCl obtained by the co-precipitation method(1–3μm).The Bio-veins played a vital role in the photocatalysis reaction system.The degradation efficiency of the Ag@AgCl/Bio-veins(CI4)was up to 3.50 times as high as pure Ag@AgCl.Furthermore,the composites also exhibited excellent recyclability and stability under both visible and solar light.This work provided a suitable strategy for nano-photocatalysts for practical application and may also offer new possibilities for the high-value utilization of biomass materials.
文摘With the start of the new year,Wen Congxiang,managing director of Ningbo Nuoding,a company specialising in the recycling of end-of-life vehicles,has been constantly on the move.Much of his time is spent coordinating with vehicle collection firms,electric bicycle manufacturers and recycled materials distributors,as he works to build partnerships focused on the targeted collection and distribution of recycled products.
基金supported by the Project of State Key Laboratory of Environment-friendly Energy Materials,Southwest University of Science and Technology(No.22FKSY17)
文摘Conventional thermosetting polymers,mostly derived from nonrenewable petroleum resources,are not reprocessable and recyclable due to their highly cross-linked three-dimensional networks and face the disadvantage of high flammability.To solve these issues,in this study,we synthesized a novel Schiff base covalent adaptable thermoset from a furan-derived tri-aldehyde monomer(TMFP)and a furan-derived di-amine monomer(DFDA).The as-prepared TMFP-DFDA-Vitrimer exhibited superior anti-flammability with a high limiting oxygen index(LOI)of 35.0%and a UL-94 V-0 rating,which was attributed to the excellent charring ability.Additionally,TMFPDFDA-Vitrimer could also be conveniently recycled by chemical decomposition under a mixed hydrochloric acid/tetrahydrofuran(HCl/THF)solution.After recycling for 5 times,the thermal,mechanical,and flame retardant properties of the recycled TMFP-DFDA-Vitrimer retained almost unchanged compared to the original one.This work provides a prime instance to develop advanced thermosetting polymers from abundant furan-based compounds.
基金supported by the National Key Research and Development Program of China(2023YFB3809300).
文摘Recycling spent lithium-ion(Li+)batteries is critical for achieving environmental conservation and the strategic recovery of essential resources.Compared with conventional methods for recovering cathode materials,which are energy-intensive and prone to secondary pollution,the direct regeneration approach has emerged as a rapid and highly efficient method,gaining widespread attention in recent years.However,this approach faces major challenges,including degraded electrochemical performances and limited economic value.This study,therefore,proposes a high-value direct regeneration strategy to convert degraded spent LiFePO_(4)(S-LFP)into a gradient manganese(Mn)-doped regenerated LiFe_(0.7)Mn_(0.3)PO_(4)/C(R-LFMP)composite.This method leverages the inherent microcracks and Li vacancies present in S-LFP,likely acting as diffusion channels for the Mn^(2+)/Li^(+)ions.Through a two-step mechanochemical ball-milling and carbothermal reduction process,this approach achieves simultaneous Li replenishment and surface-localised Mn gradient doping with enhanced structural control.Notably,the R-LFMP exhibits an exceptional electrochemical performance.At 0.1 C,it delivers a discharge capacity of 161.4 mA h g^(−1)and an energy density of 563.5 Wh kg^(−1)(representing a 60.5%improvement over S-LFP).Additionally,it maintains 83%capacity retention after 900 cycles at 0.5C,a considerable enhancement compared to commercial LFMP(62%).Furthermore,the regenerated cathode material generates a net profit of$7.102 kg^(−1),surpassing the profitability of conventional recycling methods by 90%.Overall,this study introduces a transformative and sustainable LFP regeneration technology,achieving breakthroughs in electrochemical restoration and high-value recycling,while paving the way for the closed-loop utilisation of LFP-based energy storage systems.
基金Funded by the Science and Technology Program of Gansu Province(Nos.25JRRA497,23ZDFA017)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0950000)High-level Talent Funding of Kashi。
文摘This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw resistance and durability of recycled concrete samples under varying freeze-thaw cycles.The results indicate that an appropriate addition of SAP significantly enhances the freeze-thaw resistance of recycled concrete.After 200 freeze-thaw cycles,the RS0.6 sample retained good surface integrity,demonstrating the best performance.Compared to NAC,its mass loss decreased by 1.16%,the relative dynamic modulus improved by 7.01%,and the compressive strength loss rate decreased by 5.41%.Additionally,T2 spectrum analysis revealed that adding SAP optimized the pore structure of recycled concrete and mitigated pore development during freeze-thaw cycles.As the number of freeze-thaw cycles increased,the RS0.3 and RS0.6 samples demonstrated superior frost resistance compared to NAC.However,an excessive amount of SAP increased pore expansion during subsequent freeze-thaw cycles,ultimately weakening frost resistance.
文摘Europe is grappling with a colossal textile waste problem.Over 125 million tonnes of raw materials are devoured by the global industry each year,yet a mere fraction-less than 1%-of these fibres originate from recycled textiles.The majority faces an unsustainable fate in landfills,incinerators,or is exported.A pivotal new report by Systemiq,"The Textile Recycling Breakthrough,"offers both a stark assessment and a strategic roadmap:Europe has the potential to amplify polyester textile recycling nearly tenfold by 2035,but this hinges on immediate,decisive action from policymakers and the industry.
基金financially supported by the National Natural Science Foundation of China(No.52363007)。
文摘Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.
基金Funded by the Natural Science Foundation of Jiangsu Province(No.BK20220626)the National Natural Science Foundation of China(No.52078068)+2 种基金Science and Technology Innovation Foundation of NIT(No.KCTD006)Jiangsu Marine Structure Service Performance Improvement Engineering Research CenterKey Laboratory of Jiangsu"Marine Floating Wind Power Technology and Equipment"。
文摘We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete.
文摘PKU:The super fibers combine strength and toughness In impact protection applications such as ballistic armor,vehicle shielding,and aerospace,the dynamic strength and dynamic toughness of fiber materials are critical performance indicators determining protective efficacy.However,widely used polymeric fibers still face significant challenges preventing full utilization of the material’s intrinsic strength and toughness.
基金Funded by Natural Science Foundation of Guangxi(No.2025GXNSFBA069565)Guangxi Science and Technology Program(No.AD25069101)Guangxi Bagui Scholars Fund。
文摘Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands.
