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
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
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
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
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
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
Cadmium(Cd)contamination of soil is a global environmental issue.Traditional remediation techniques such as immobilization,leaching,and phytoextraction have numerous shortcomings,which has led to growing interest in t...Cadmium(Cd)contamination of soil is a global environmental issue.Traditional remediation techniques such as immobilization,leaching,and phytoextraction have numerous shortcomings,which has led to growing interest in the development of low-cost,high-efficiency,and environmentally friendly agents for removing Cd from soil.In this study,four magnetite(Fe_(3)O_(4))/polyaniline(PANI)nanocomposites,Fe_(3)O_(4)(1.0)/PANI,Fe_(3)O_(4)(1.5)/PANI,Fe_(3)O_(4)(2.0)/PANI,and Fe_(3)O_(4)(2.5)/PANI,were developed using 4 mL aniline monomer and 1.0,1.5,2.0,and 2.5 g Fe_(3)O_(4),respectively,and used as remediation agents with magnetic separation and regeneration capabilities.The Cd adsorption isotherms showed a better fit to the Langmuir model,with Fe_(3)O_(4)(1.5)/PANI exhibiting the highest Cd adsorption capacity of 47.62 mg g^(-1) at 25℃.Then,Fe_(3)O_(4)(1.5)/PANI was used to remediate four Cd-contaminated soils typical in China(black,brown,cinnamon,and red),all with a Cd content of 180 mg kg^(-1) after spiking.The results showed that the total Cd removal efficiency was satisfactory at 25.25%–38.91%and the exchangeable Cd removal efficiency was 36.03%on average.In addition,soil basic properties did not show significant changes after remediation.Regarding the regeneration performance,a higher total Cd removal efficiency(27.89%–44.96%)was achieved after the first regeneration cycle of Fe_(3)O_(4)(1.5)/PANI.After two regeneration cycles,Fe_(3)O_(4)(1.5)/PANI exhibited decreased total Cd removal efficiency compared to after the first regeneration,but its efficiency remained above 95%of or higher than those of virgin Fe_(3)O_(4)(1.5)/PANI.The synthetic process of Fe_(3)O_(4)/PANI was simple and cost-effective,and Fe_(3)O_(4)/PANI exhibited a high Cd removal efficiency with easy recovery and recyclability.Therefore,Fe_(3)O_(4)/PANI is a promising solution for the sustainable and efficient remediation of Cd-contaminated soils,especially for the reclamation of highly contaminated development land.展开更多
Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the ...Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.展开更多
Sustainably managing vehicles at their end-of-life stage(ELVs)presents significant potential forresource recovery,effectively addressing resource scarcity through the closure of the material loop.While ELVs in countri...Sustainably managing vehicles at their end-of-life stage(ELVs)presents significant potential forresource recovery,effectively addressing resource scarcity through the closure of the material loop.While ELVs in countries like Morocco have traditionally been treated as waste rather than secondaryresource material(SRM),they have the potential to reduce reliance on primary materials when usedjudiciously.Despite policymakers aiming for increased resource efficiency in the automobile sector,there is limited research exploring the role of the informal sector in recovering materials and parts fromELVs.This study investigates the ELV processing scenario at Salmia scrap market,recognized as one of Africa’s largest informal markets for ELVs.Using a mass-balance approach,the disposal of sedan cars isexamined,and a conceptual framework illustrating the process flow and interactions among multiplestakeholders is developed.From sampled sedan cars,approximately 7% of aluminum and 76%of iron,by weight,are recovered.These findings contribute to estimating the potential for recycling andrecovering materials from ELVs processed by the informal sector in Morocco.In a standard operationalcontext,estimations suggest that the sector holds substantial potential to recover aluminum and iron by2030.This underscores the importance of formalizing operations and integrating informal players intothe value chain to effectively address resource scarcity within a circular economy.展开更多
It is a challenging task to efficiently convert deleterious hydrogen sulfide(H_(2)S)into less harmful products such as SO_(4)^(2-)species.In an effort to address such issue,a step-scheme(S-scheme)heterojunction photoc...It is a challenging task to efficiently convert deleterious hydrogen sulfide(H_(2)S)into less harmful products such as SO_(4)^(2-)species.In an effort to address such issue,a step-scheme(S-scheme)heterojunction photocatalyst has been built by concatenating TiO_(2)(P25)and ultrathin Bi_(4)O_(5)Br_(2)into TiO_(2)/Bi_(4)O_(5)Br_(2)(namely,x-TB-y:x and y denote the molar ratio of TiO_(2):Bi_(4)O_(5)Br_(2)and pH value for solution-based synthesis,respectively)via in-situ hydrothermal method.The S-scheme charge transfer pathway in TB is confirmed by electron spin resonance and band structure analysis while experimental data and density functional theory calculations suggest the formation of an internal electric field to facilitate the separation and transfer of photoinduced charge carriers.Accordingly,the optimized heterojunction photocatalyst,i.e.,5-TB-9,showcases significantly high(>99%)removal efficiency against 10 ppm H_(2)S in a 17 L chamber within 12 minutes(removal kinetic rate r:0.7 mmol·h^(-1)·g^(-1),specific clean air delivery rate SCADR:5554 L·h^(-1)·g^(-1),quantum yield QY:3.24 E-3 molecules·photon^(-1),and space-time yield STY:3.24 E-3 molecules·photon^(-1)·mg^(-1)).Combined analysis of in-situ diffuse reflectance infrared Fourier transform adsorption spectra and gas chromatography-mass spectrometry allows to evaluate the mechanisms leading to the complete degradation of H_(2)S(i.e.,into SO_(4)^(2-)without forming any intermediate species).This work demonstrates the promising remediation potential of an S-scheme TiO_(2)/Bi_(4)O_(5)Br_(2)photocatalyst against hazardous H_(2)S gas for sustainable environmental remediation.展开更多
Lithium-ion batteries(LIBs)are the most popular energy storage devices due to their high energy density,high operating voltage,and long cycle life.However,green and effective recycling methods are needed because LIBs ...Lithium-ion batteries(LIBs)are the most popular energy storage devices due to their high energy density,high operating voltage,and long cycle life.However,green and effective recycling methods are needed because LIBs contain heavy metals such as Co,Ni,and Mn and organic compounds inside,which seriously threaten human health and the environment.In this work,we review the current status of spent LIB recycling,discuss the traditional pyrometallurgical and hydrometallurgical recovery processes,and summarize the existing short-process recovery technologies such as salt-assisted roasting,flotation processes,and direct recycling.Finally,we analyze the problems and potential research prospects of the current recycling process,and point out that the multidisciplinary integration of recycling will become the mainstream technology for the development of spent LIBs.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
Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and ...Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and persist primarily in shallowsurface soils,increasing evidence shows that these compounds can leach into the groundwater.Herein,we compare the leachabilities of PBDEs vs.PAHs from contaminated soils collected at an e-waste recycling site in Tianjin,China.Considerable amounts of BDE-209(0.3–2 ng/L)and phenanthrene(42–106 ng/L),the most abundant PBDE and PAH at the site,are detected in the effluents of columns packed with contaminated soils,with the specific concentrations varying with hydrodynamic and solution chemistry conditions.Interestingly,the leaching potential of BDE-209 appears to be closely related to the release of colloidal mineral particles,whereas the leachability of phenanthrene correlates well with the concentration of dissolved organic carbon in the effluent,but showing essentially no correlation with the concentration of mineral particles.The surprisingly different trends of the leachability observed between BDE-209 and phenanthrene is counterintuitive,as PBDEs and PAHs often co-exist at e-waste recycling sites(particularly at the sites wherein incineration is being practiced)and share many similarities in terms of physicochemical properties.One possible explanation is that due to its extremely low solubility,BDE-209 predominantly exists in free-phase(i.e.,as solid(nano)particles),whereas the more soluble phenanthrene is mainly sorbed to soil organic matter.Findings in this study underscore the need to better understand the mobility of highly hydrophobic organic contaminants at contaminated sites for improved risk management.展开更多
Amid the escalating plastic pollution issue, the development of biodegradable and recyclable polymeric materials has become a focus within the scientific community. Chain extenders, which are an important class of com...Amid the escalating plastic pollution issue, the development of biodegradable and recyclable polymeric materials has become a focus within the scientific community. Chain extenders, which are an important class of compounds, facilitate the elongation of polymer chains through reactive functional groups, thereby enhancing the performance of the materials. Epoxy-based chain extenders, due to their cost-effectiveness, low toxicity, high reaction efficiency, and effective reactivity with hydroxyl and carboxyl groups, have emerged as a promising class of chain extenders. This manuscript comprehensively elaborates on the varieties, structural characteristics, and performance of chain extenders, the challenges they face, and the methods for their modification. Special emphasis is placed on the application of epoxy-based chain extenders in biodegradable polymers, such as polylactic acid (PLA), and their subsequent influence on the structural and performance properties of these materials.展开更多
Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling sites.The association of PBDEs with soil colloids has been observed,indicating the potenti...Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling sites.The association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated transport.However,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely unknown.Herein,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous media.The colloids released froma soil sample collected at an e-waste recycling site in Tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).The colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater environments.Notably,under all the tested conditions(i.e.,varying flow velocity,pH,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids,even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions involved.Additionally,the mass of BDE-209 retained in the columns also correlates strongly with themass of retained colloids.Apparently,the PBDEs remain bound to soil colloids during transport in porous media.Findings in this study indicate that soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective carrier.This might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.展开更多
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.
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.
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financially supported by the National Natural Science Foundation of China(No.41807116)the Natural Science Foundation of Fujian Province,China(Nos.2023J01418,2019J05035,and 2022N0024)+2 种基金the Scientific and Technological Innovation Project of China Metallurgical Geology Bureau(No.CMGBKY202301)the Independent Innovation Foundation of Tianjin University and Fuzhou University,China(No.TF2023-3)the Fuzhou University Testing Fund of Precious Apparatus,China(No.2023T014).
文摘Cadmium(Cd)contamination of soil is a global environmental issue.Traditional remediation techniques such as immobilization,leaching,and phytoextraction have numerous shortcomings,which has led to growing interest in the development of low-cost,high-efficiency,and environmentally friendly agents for removing Cd from soil.In this study,four magnetite(Fe_(3)O_(4))/polyaniline(PANI)nanocomposites,Fe_(3)O_(4)(1.0)/PANI,Fe_(3)O_(4)(1.5)/PANI,Fe_(3)O_(4)(2.0)/PANI,and Fe_(3)O_(4)(2.5)/PANI,were developed using 4 mL aniline monomer and 1.0,1.5,2.0,and 2.5 g Fe_(3)O_(4),respectively,and used as remediation agents with magnetic separation and regeneration capabilities.The Cd adsorption isotherms showed a better fit to the Langmuir model,with Fe_(3)O_(4)(1.5)/PANI exhibiting the highest Cd adsorption capacity of 47.62 mg g^(-1) at 25℃.Then,Fe_(3)O_(4)(1.5)/PANI was used to remediate four Cd-contaminated soils typical in China(black,brown,cinnamon,and red),all with a Cd content of 180 mg kg^(-1) after spiking.The results showed that the total Cd removal efficiency was satisfactory at 25.25%–38.91%and the exchangeable Cd removal efficiency was 36.03%on average.In addition,soil basic properties did not show significant changes after remediation.Regarding the regeneration performance,a higher total Cd removal efficiency(27.89%–44.96%)was achieved after the first regeneration cycle of Fe_(3)O_(4)(1.5)/PANI.After two regeneration cycles,Fe_(3)O_(4)(1.5)/PANI exhibited decreased total Cd removal efficiency compared to after the first regeneration,but its efficiency remained above 95%of or higher than those of virgin Fe_(3)O_(4)(1.5)/PANI.The synthetic process of Fe_(3)O_(4)/PANI was simple and cost-effective,and Fe_(3)O_(4)/PANI exhibited a high Cd removal efficiency with easy recovery and recyclability.Therefore,Fe_(3)O_(4)/PANI is a promising solution for the sustainable and efficient remediation of Cd-contaminated soils,especially for the reclamation of highly contaminated development land.
基金financially supported by the National Key R&D Program of China(No.2021YFA1501700)the National Natural Science Foundation of China(Nos.22371194 and 22301197)Fundamental Research Funds from Sichuan University(Nos.2023SCUNL103 and 2024SCUQJTX005)。
文摘Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.
文摘Sustainably managing vehicles at their end-of-life stage(ELVs)presents significant potential forresource recovery,effectively addressing resource scarcity through the closure of the material loop.While ELVs in countries like Morocco have traditionally been treated as waste rather than secondaryresource material(SRM),they have the potential to reduce reliance on primary materials when usedjudiciously.Despite policymakers aiming for increased resource efficiency in the automobile sector,there is limited research exploring the role of the informal sector in recovering materials and parts fromELVs.This study investigates the ELV processing scenario at Salmia scrap market,recognized as one of Africa’s largest informal markets for ELVs.Using a mass-balance approach,the disposal of sedan cars isexamined,and a conceptual framework illustrating the process flow and interactions among multiplestakeholders is developed.From sampled sedan cars,approximately 7% of aluminum and 76%of iron,by weight,are recovered.These findings contribute to estimating the potential for recycling andrecovering materials from ELVs processed by the informal sector in Morocco.In a standard operationalcontext,estimations suggest that the sector holds substantial potential to recover aluminum and iron by2030.This underscores the importance of formalizing operations and integrating informal players intothe value chain to effectively address resource scarcity within a circular economy.
文摘It is a challenging task to efficiently convert deleterious hydrogen sulfide(H_(2)S)into less harmful products such as SO_(4)^(2-)species.In an effort to address such issue,a step-scheme(S-scheme)heterojunction photocatalyst has been built by concatenating TiO_(2)(P25)and ultrathin Bi_(4)O_(5)Br_(2)into TiO_(2)/Bi_(4)O_(5)Br_(2)(namely,x-TB-y:x and y denote the molar ratio of TiO_(2):Bi_(4)O_(5)Br_(2)and pH value for solution-based synthesis,respectively)via in-situ hydrothermal method.The S-scheme charge transfer pathway in TB is confirmed by electron spin resonance and band structure analysis while experimental data and density functional theory calculations suggest the formation of an internal electric field to facilitate the separation and transfer of photoinduced charge carriers.Accordingly,the optimized heterojunction photocatalyst,i.e.,5-TB-9,showcases significantly high(>99%)removal efficiency against 10 ppm H_(2)S in a 17 L chamber within 12 minutes(removal kinetic rate r:0.7 mmol·h^(-1)·g^(-1),specific clean air delivery rate SCADR:5554 L·h^(-1)·g^(-1),quantum yield QY:3.24 E-3 molecules·photon^(-1),and space-time yield STY:3.24 E-3 molecules·photon^(-1)·mg^(-1)).Combined analysis of in-situ diffuse reflectance infrared Fourier transform adsorption spectra and gas chromatography-mass spectrometry allows to evaluate the mechanisms leading to the complete degradation of H_(2)S(i.e.,into SO_(4)^(2-)without forming any intermediate species).This work demonstrates the promising remediation potential of an S-scheme TiO_(2)/Bi_(4)O_(5)Br_(2)photocatalyst against hazardous H_(2)S gas for sustainable environmental remediation.
基金financial support by the National Natural Science Foundation of China(No.52374293)Zhongyuan Science and Technology Innovation Leading Talent Project,China(No.224200510025)+1 种基金the Science and Technology Innovation Program of Hunan Province,China(No.2022RC1123)One of the authors,Hong-bo ZENG,gratefully acknowledges the support from the Natural Sciences and Engineering Research Council of Canada(NSERC)and the Canada Research Chairs Program.
文摘Lithium-ion batteries(LIBs)are the most popular energy storage devices due to their high energy density,high operating voltage,and long cycle life.However,green and effective recycling methods are needed because LIBs contain heavy metals such as Co,Ni,and Mn and organic compounds inside,which seriously threaten human health and the environment.In this work,we review the current status of spent LIB recycling,discuss the traditional pyrometallurgical and hydrometallurgical recovery processes,and summarize the existing short-process recovery technologies such as salt-assisted roasting,flotation processes,and direct recycling.Finally,we analyze the problems and potential research prospects of the current recycling process,and point out that the multidisciplinary integration of recycling will become the mainstream technology for the development of spent LIBs.
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.
基金supported by the National Key Research and Development Program of China(No.2019YFC1804202)the National Natural Science Foundation of China(Nos.22020102004 and 22125603)+1 种基金Tianjin Municipal Science and Technology Bureau(No.21JCZDJC00280)the Fundamental Research Funds for the Central Universities,and the Ministry of Education of China(No.T2017002).
文摘Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and persist primarily in shallowsurface soils,increasing evidence shows that these compounds can leach into the groundwater.Herein,we compare the leachabilities of PBDEs vs.PAHs from contaminated soils collected at an e-waste recycling site in Tianjin,China.Considerable amounts of BDE-209(0.3–2 ng/L)and phenanthrene(42–106 ng/L),the most abundant PBDE and PAH at the site,are detected in the effluents of columns packed with contaminated soils,with the specific concentrations varying with hydrodynamic and solution chemistry conditions.Interestingly,the leaching potential of BDE-209 appears to be closely related to the release of colloidal mineral particles,whereas the leachability of phenanthrene correlates well with the concentration of dissolved organic carbon in the effluent,but showing essentially no correlation with the concentration of mineral particles.The surprisingly different trends of the leachability observed between BDE-209 and phenanthrene is counterintuitive,as PBDEs and PAHs often co-exist at e-waste recycling sites(particularly at the sites wherein incineration is being practiced)and share many similarities in terms of physicochemical properties.One possible explanation is that due to its extremely low solubility,BDE-209 predominantly exists in free-phase(i.e.,as solid(nano)particles),whereas the more soluble phenanthrene is mainly sorbed to soil organic matter.Findings in this study underscore the need to better understand the mobility of highly hydrophobic organic contaminants at contaminated sites for improved risk management.
文摘Amid the escalating plastic pollution issue, the development of biodegradable and recyclable polymeric materials has become a focus within the scientific community. Chain extenders, which are an important class of compounds, facilitate the elongation of polymer chains through reactive functional groups, thereby enhancing the performance of the materials. Epoxy-based chain extenders, due to their cost-effectiveness, low toxicity, high reaction efficiency, and effective reactivity with hydroxyl and carboxyl groups, have emerged as a promising class of chain extenders. This manuscript comprehensively elaborates on the varieties, structural characteristics, and performance of chain extenders, the challenges they face, and the methods for their modification. Special emphasis is placed on the application of epoxy-based chain extenders in biodegradable polymers, such as polylactic acid (PLA), and their subsequent influence on the structural and performance properties of these materials.
基金supported by the National Key Research and Development Program of China(No.2019YFC1804202)the National Natural Science Foundation of China(No.22020102004)+1 种基金the Tianjin Municipal Science and Technology Bureau(No.21JCZDJC00280)the Fundamental Research Funds for the Central Universities by the Ministry of Education of China(No.T2017002).
文摘Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling sites.The association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated transport.However,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely unknown.Herein,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous media.The colloids released froma soil sample collected at an e-waste recycling site in Tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).The colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater environments.Notably,under all the tested conditions(i.e.,varying flow velocity,pH,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids,even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions involved.Additionally,the mass of BDE-209 retained in the columns also correlates strongly with themass of retained colloids.Apparently,the PBDEs remain bound to soil colloids during transport in porous media.Findings in this study indicate that soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective carrier.This might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.
