A number of chlorumethylated polystyrenes were synthesized and tried to immobilize aminoacylase from Aspergillus oryzae and many factors which affected immobilized enzyme activity were studied in detail. The results i...A number of chlorumethylated polystyrenes were synthesized and tried to immobilize aminoacylase from Aspergillus oryzae and many factors which affected immobilized enzyme activity were studied in detail. The results indicated that the immobilized enzyme on support(IAR-1) possessed high enzymatic activity and high stability.展开更多
A study has been conducted on the synthesis and characterization of a kind of novel polyrotaxanes comprisingα- cyclodextrins (α-CDs) threaded on triblock eopolymers with poly(ethylene glycol) (PEG) as a central axle...A study has been conducted on the synthesis and characterization of a kind of novel polyrotaxanes comprisingα- cyclodextrins (α-CDs) threaded on triblock eopolymers with poly(ethylene glycol) (PEG) as a central axle and flanked by two low molecular weight polystyrenes as outer stoppers.Styrene was allowed to telomerize with polypseudorotaxanes as chain transfer agents made from the self-assembly of a distal thiol-capped PEG with a varying amount ofα-CDs in the presence of a redox initiation system at 40~C i...展开更多
Polystyrene nanoparticles pose significant toxicological risks to aquatic ecosystems,yet their impact on zebrafish(Danio rerio)embryonic development,particularly erythropoiesis,remains underexplored.This study used si...Polystyrene nanoparticles pose significant toxicological risks to aquatic ecosystems,yet their impact on zebrafish(Danio rerio)embryonic development,particularly erythropoiesis,remains underexplored.This study used single-cell RNA sequencing to comprehensively evaluate the effects of polystyrene nanoparticle exposure on erythropoiesis in zebrafish embryos.In vivo validation experiments corroborated the transcriptomic findings,revealing that polystyrene nanoparticle exposure disrupted erythrocyte differentiation,as evidenced by the decrease in mature erythrocytes and concomitant increase in immature erythrocytes.Additionally,impaired heme synthesis further contributed to the diminished erythrocyte population.These findings underscore the toxic effects of polystyrene nanoparticles on hematopoietic processes,highlighting their potential to compromise organismal health in aquatic environments.展开更多
Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectros...Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectroscopy,thermogravimetric(TG)analysis,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state^(13)C nuclear magnetic resonance spectroscopy.The crucible coal-blending coking tests were carried out using an industrial coal mixture and the treated-PS with the highest caking index(PS300)or raw PS.Some properties of the resultant cokes were also analyzed.It was demonstrated that the caking index of PS dramatically increased by LTPT;however,exceeding 300℃ did not yield any benefit.The caking index increased due to the formation of the caking components,whose molecules are medium in size,caused by LTPT.Additionally,the coke reactivity index of the coke obtained from the mixture containing PS300 decreased by 5.1%relative to that of the coke made from the mixture with PS and the coke strength after reaction index of the former increased by 7.3% compared with that of the latter,suggesting that the ratio of depolymerized PS used for coal-blending coking could increase relative to that of PS.展开更多
Polymethyl methacrylate(PMMA)is an optically transparent thermoplastic with favorable processing conditions.In this study,a series of plastic scintillators are prepared via thermal polymerization,and the impact of PMM...Polymethyl methacrylate(PMMA)is an optically transparent thermoplastic with favorable processing conditions.In this study,a series of plastic scintillators are prepared via thermal polymerization,and the impact of PMMA content on their transparency and pulse shape discrimination(PSD)ability is investigated.The fabricated samples,comprising a polystyrene(PS)-PMMA matrix,30.0 wt%2,5-diphenyloxazole(PPO),and 0.2 wt%9,10-diphenylanthracene(DPA),exhibit high transparency with transmissivity ranging from 70.0 to 90.0%(above 415.0 nm)and demonstrate excellent n/γdiscrimination capability.Transparency increased with increasing PMMA content across the entire visible light spectrum.However,the PSD performance gradually deteriorated when the aromatic matrix was replaced with PMMA.The scintillator containing 20.0 wt%PMMA demonstrated the best stability concerning PSD properties and relative light yields.展开更多
Microplastics(MPs)are one of the most concerning pollutants that affects the health and growth of aquatic organisms.We characterized the MPs dispersion in the milli-Q water and seawater,and evaluated the effects of MP...Microplastics(MPs)are one of the most concerning pollutants that affects the health and growth of aquatic organisms.We characterized the MPs dispersion in the milli-Q water and seawater,and evaluated the effects of MPs on the gut epithelial cells of brine shrimp using three sizes of polystyrene(PS)microbeads(0.05,0.5,and 5μm,respectively).Results show that microbeads evenly dispersed in milli-Q water,but exhibited aggregation tendency in seawater associating with the particle size.Apart from a reduced survival rate,we observed the structure changes in the gut epithelium that the smaller size of PS microbeads resulted in an increased reactive oxygen species(ROS)and higher apoptosis-related genes expression.Moreover,exposure to all size of PS microbeads led to increased green fluorescence of J-monomer,indicating the declined mitochondrial membrane potential.Therefore,exposure to PS microbeads led to significantly size-dependent toxicity on brine shrimp.Especially,0.05-μm PS microbeads were more toxic,leading to severe oxidative stress and activation of the p53-Bax-Bcl2 pathway,ultimately resulting in cellular apoptosis and gut damage.These findings are important to understand the mechanism of MPs toxicity and its potential ecological risks to marine aquatic animals.展开更多
Nanoplastics exhibit greater environmental biotoxicity than microplastics and can be ingested by humans through major routes such as tap water,bottled water and other drinking water.Nanoplastics present a challenge fo...Nanoplastics exhibit greater environmental biotoxicity than microplastics and can be ingested by humans through major routes such as tap water,bottled water and other drinking water.Nanoplastics present a challenge for air flotation due to their minute particle size,negative surface potential,and similar density to water.This study employed dodecyltrimethylammonium chloride(DTAC)as a modifier to improve conventional air flotation,which significantly enhanced the removal of polystyrene nanoplastics(PSNPs).Conventional air flotation removed only 3.09%of PSNPs,while air flotation modified by dodecyltrimethylammonium chloride(DTAC-modified air flotation)increased the removal of PSNPs to 98.05%.The analysis of the DTAC-modified air flotation mechanism was conducted using a combination of instruments,including a zeta potential analyzer,contact angle meter,laser particle size meter,high definition camera,scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and Fourier transform infrared spectrometer(FTIR).The results indicated that the incorporation of DTAC reversed the electrostatic repulsion between bubbles and PSNPs to electrostatic attraction,significantly enhancing the hydrophobic force in the system.This,in turn,improved the collision adhesion effect between bubbles and PSNPs.The experimental results indicated that even when the flotation time was reduced to 7min,the DTACmodified air flotation still achieved a high removal rate of 96.26%.Furthermore,changes in aeration,pH,and ionic strength did not significantly affect the performance of the modified air flotation for the removal of PSNPs.The removal rate of PSNPs in all three water bodies exceeded 95%.The DTAC-modified air flotation has excellent resistance to interference from complex conditions and shows great potential for practical application.展开更多
Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interfac...Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interface anchoring,and inorganic particles have gained extensive attention recently owing to their large interfacial desorption energy,while their low affinity to bulk components is a drawback.In this study,an interfacial atom transfer radical polymerization(ATRP)technique was employed to grow polystyrene(PS)and poly(2-hydroxyethyl methacrylate)(PHEMA)simultaneously on different hemispheres of Br-functionalized SiO_(2) nanoparticles to stabilize a Pickering emulsion,whereby a brush-type Janus nanoparticle(SiO_(2)@JNP)was developed.The polymer brushes were well-characterized,and the Janus feature was validated by transmission electron microscope(TEM)observation of the sole hemisphere grafting of SiO_(2)-PS as a control sample.SiO_(2)@JNP was demonstrated to be an efficient compatibilizer for a PS/poly(methyl methacrylate)(PMMA)immiscible blend,and the droplet-matrix morphology was significantly refined.The mechanical strength and toughness of the blend were synchronously enhanced at a low content SiO_(2)@JNP optimized~0.9 wt%,with the tensile strength,elongation at break and impact strength increased by 17.7%,26.6%and 19.6%,respectively.This enhancement may be attributed to the entanglements between the grafted polymer brushes and individual components that improve the particle-bulk phase affinity and enforce interfacial adhesion.展开更多
Microplastics(MPs)have garnered significant international scrutiny as an emerging environmental pollutant,constituting one of the four principal global environmental threats and posing potential health hazards to huma...Microplastics(MPs)have garnered significant international scrutiny as an emerging environmental pollutant,constituting one of the four principal global environmental threats and posing potential health hazards to humans.However,data on the impact of MPs on the early life of the commercially important fish remain limited.In this study,polystyrene microspheres(PS-MPs)(1 and 5μm)were used to investigate the effects of MPs on the growth,development,and metabolism in early life stages of large yellow croaker Pseudosciaena crocea.Results indicate that MPs were enriched in the gastrointestinal tract and gills of the fish.In addition,PS-MPs(1μm)exhibited no obvious effects on embryo hatching and heart rates,while increased the mortality rate(23.00%vs.control 14.99%)and decreased the body length(4098.61±447.03μm vs.control with 2827.04±254.75μm)of the larvae at the highest exposure concentration(5×10^(4)items/L).Metabolomics analysis revealed that PS-MPs(5μm)induced mild perturbations in phospholipid metabolism,specifically alterations in phosphatidylethanolamine(PE)levels.These changes influenced the cell membranes of juvenile fish,and consequently elicited inflammatory responses,disrupted lipid homeostasis,and affected other critical physiological processes.Ultimately,these effects may avoid the growth retardation and potential mortality.Therefore,PS-MPs could affect negatively the fish health in the early life stage,which has implications for aquatic ecosystems.展开更多
The process of disposing of expanded polystyrene (EPS) is by burning it in municipal incinerators. This process gives off EPS microplastics, which can find their way into water, food, blood, and major organ systems. Z...The process of disposing of expanded polystyrene (EPS) is by burning it in municipal incinerators. This process gives off EPS microplastics, which can find their way into water, food, blood, and major organ systems. Zophobas morio larvae are capable of consuming and breaking down EPS within their digestive tracts by minimizing the spread of microplastics. Studies of the consumption of EPS by Z. morio larvae are typically conducted under white or no visible light treatments. This study tested whether the color of visible light influenced the consumption rate of EPS by Z. morio larvae. If Z. morio larvae consume EPS under visible light, then visible light will influence the amount of EPS consumed. If results suggest that the consumption rate is influenced by visible light colors, then Z. morio larvae could be a solution for recycling EPS. This study’s procedure placed Z. morio larvae into 25 jars under one of six visible light treatments of red, yellow, green, blue, white, and no visible light. Each jar contained a pre-weighed block of EPS and six Z. morio larvae. After two weeks, the Z. morio larvae were removed from the jars, and the difference between each pre-weighed EPS block and the weight of the same partially consumed block was recorded in three trials. The data indicates that green and blue visible light treatments resulted in the greatest amount of EPS consumed by Z. morio larvae while the red and yellow had the least amount of EPS consumed by the Z. morio larvae. In conclusion, results indicate that green and blue visible light, compared to the no visible light treatment, could be used to influence the Z. morio larvae to consume more EPS. Green and blue visible light and Z. morio larvae could make the recycling process of EPS more environmentally friendly when used in households or by local environmental organizations.展开更多
The adsorption kinetics of polystyrene[1-butyl-3-methylimidazolium][bis(2,4,4-trimethylpentyl)phosphinate](PS[C_(4)mim][C272])towards V(V)in acidic leachate was explored under ultrasound.The effects of ultrasonic powe...The adsorption kinetics of polystyrene[1-butyl-3-methylimidazolium][bis(2,4,4-trimethylpentyl)phosphinate](PS[C_(4)mim][C272])towards V(V)in acidic leachate was explored under ultrasound.The effects of ultrasonic power and V(V)concentration on the adsorption performance of PS[C_(4)mim][C272]were investigated.The results showed that ultrasonic radiation significantly shortened the adsorption equilibrium time and improved the adsorption performance of PS[C_(4)mim][C272]compared with the conventional oscillation.At an ultrasonic power of 200 W,the equilibrium adsorption capacity of PS[C_(4)mim][C272]reached its maximum of 311.58 mg/g.The kinetic model fitting results showed that the adsorption process of PS[C_(4)mim][C272]strictly followed the pseudo-second-order kinetic model under ultrasound.Analysis using the shrinking core model and the Weber−Morris model showed that the adsorption process of PS[C_(4)mim][C272]was primarily controlled by intra-particle diffusion mechanism.The adsorption isotherm model study showed that the Langmuir isotherm model could effectively fit the adsorption process of PS[C_(4)mim][C272]under ultrasound.展开更多
Polystyrene(PS)is rich in plastic materials,but it produces a large amount of waste every year,causing a huge burden on the environment.Although PS plastic is the source of a common"white pollution"in daily ...Polystyrene(PS)is rich in plastic materials,but it produces a large amount of waste every year,causing a huge burden on the environment.Although PS plastic is the source of a common"white pollution"in daily life,it still has a high utilization value.At the same time,the flammability of PS material determines that it cannot be applicated in places where fire accidents occur frequently.As a result,its application has been greatly limited.In order to realize the efficient utilization of waste PS and broaden its scope of application,PS was modified by hyper-crosslinking in order to improve its fire-retardant performance.In this method,the PS solution with high purity was obtained by dissolving waste PS foam with 1,2-dichloroethane(DCE),and then the hyper-crosslinked polymer with high specific surface area was prepared by adding cross-linking agent formaldehyde dimethyl acetal(FDA)and a Lewis-acid catalyst ferric chloride(FeCl_(3)).Further studies showed that the effects of the amount of cross-linking agent FDA,catalyst FeCl_(3) and PS on the reaction products were different.In addition,compared the as-prepared fire-retardant materials with PS foam from the aspects of flame retardancy and thermal insulation,it can be concluded that the fire-retardant performance of the materials prepared by this method has been significantly enhanced.And it is proved that this method is feasible towards the preparation of a large number of fire-retardant composite materials by using a scale-up experiment.展开更多
Exploiting high-performance yet low-cost hard carbon anodes is crucial to advancing the state-of-the-art sodium-ion batteries.However,the achievement of superior initial Coulombic efficiency(ICE)and high Na-storage ca...Exploiting high-performance yet low-cost hard carbon anodes is crucial to advancing the state-of-the-art sodium-ion batteries.However,the achievement of superior initial Coulombic efficiency(ICE)and high Na-storage capacity via low-temperature carbonization remains challenging due to the presence of tremendous defects with few closed pores.Here,a facile hybrid carbon framework design is proposed from the polystyrene precursor bearing distinct molecular bridges at a low pyrolysis temperature of 800℃ via in situ fusion and embedding strategy.This is realized by integrating triazine-and carbonylcrosslinked polystyrene nanospheres during carbonization.The triazine crosslinking allows in situ fusion of spheres into layered carbon with low defects and abundant closed pores,which serves as a matrix for embedding the well-retained carbon spheres with nanopores/defects derived from carbonyl crosslinking.Therefore,the hybrid hard carbon with intimate interface showcases synergistic Na ions storage behavior,showing an ICE of 70.2%,a high capacity of 279.3 mAh g^(-1),and long-term 500 cycles,superior to carbons from the respective precursor and other reported carbons fabricated under the low carbonization temperature.The present protocol opens new avenues toward low-cost hard carbon anode materials for high-performance sodiumion batteries.展开更多
Microplastics(MPs)have attracted growing attention worldwide as an increasingly prevalent environmental pollutant.In addition,chicken meat is currently the most widely consumed kind of poultry in the global market.Con...Microplastics(MPs)have attracted growing attention worldwide as an increasingly prevalent environmental pollutant.In addition,chicken meat is currently the most widely consumed kind of poultry in the global market.Consumer demand for chicken is on the rise both at home and abroad.As a result,the safety of chicken raising has also received significant attention.The lungs play an essential role in the physiological activities of chickens,and they are also the most vulnerable organs.Lung injury is difficult to repair after the accumulation of contaminants,and the mortality rate is high,which brings huge economic losses to farmers.The research on the toxicity of MPs has mainly focused on the marine ecosystem,while the mechanisms of toxicity and lung damage in chickens have been poorly studied.Thus,this study explored the effects of exposure to polystyrene microplastics(PS-MPs)at various concentrations for 42 d on chicken lungs.PS-MPs could cause lung pathologies and ultrastructural abnormalities,such as endoplasmic reticulum(ER)swelling,inflammatory cell infiltration,chromatin agglutination,and plasma membrane rupture.Simultaneously,PS-MPs increased the expression of genes related to the heat shock protein family(Hsp60,Hsp70,and Hsp90),ER stress signaling(activating) transcription factor 6(ATF0),ATF4,protein kinase RNA-like ER kinase(PERK),and eukaryotic translation initiation factor 2 subunitα(eIF2a),pyroptosis-related genes(NOD)-,LRR-and pyrin domain-containing protein 3(NLRP3),apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),interleukin-1β(IL-1β),cysteinyl aspartate-specific proteinase 1(Caspasel),and gasdermin-D(GSDMD),and the inflammatory signaling pathway(nuclear factor-kB(NF-kB),inducible nitric oxide synthase(iNOS),and cyclooxygenase-2(COX-2).The above results showed that PS-MP exposure could result in lung stress,ER stress,pyroptosis,and inflammation in broilers.Our findings provide new scientific clues for further research on the mechanisms of physical health and toxicology regardingMPs.展开更多
Many types of plastic products,including polystyrene,have long been used in commercial and industrial applications.Microplastics and nanoplastics,plastic particles derived from these plastic products,are emerging as e...Many types of plastic products,including polystyrene,have long been used in commercial and industrial applications.Microplastics and nanoplastics,plastic particles derived from these plastic products,are emerging as environmental pollutants that can pose health risks to a wide variety of living organisms,including humans.However,it is not well understood how microplastics and nanoplastics affect cellular functions and induce stress responses.Humans can be exposed to polystyrene-microplastics and polystyrene-nanoplastics through ingestion,inhalation,or skin contact.Most ingested plastics are excreted from the body,but inhaled plastics may accumulate in the lungs and can even reach the brain via the nose-to-brain route.Small-sized polystyrene-nanoplastics can enter cells by endocytosis,accumulate in the cytoplasm,and cause various cellular stresses,such as inflammation with increased pro-inflammatory cytokine production,oxidative stress with generation of reactive oxygen species,and mitochondrial dysfunction.They induce autophagy activation and autophagosome formation,but autophagic flux may be impaired due to lysosomal dysfunction.Unless permanently exposed to polystyrene-nanoplastics,they can be removed from cells by exocytosis and subsequently restore cellular function.However,neurons are very susceptible to this type of stress,thus even acute exposure can lead to neurodegeneration without recovery.This review focuses specifically on recent advances in research on polystyrene-nanoplastic-induced cytotoxicity and neurotoxicity.Furthermore,in this review,based on mechanistic studies of polystyrene-nanoplastics at the cellular level other than neurons,future directions for overcoming the negative effects of polystyrene-nanoplastics on neurons were suggested.展开更多
Polystyrene resins(PS)have been practical ion exchangers for radionuclides removal from water.However,nonspecific effects of ion exchange groups continue to be a major obstacle for emergency treatment with coexisting ...Polystyrene resins(PS)have been practical ion exchangers for radionuclides removal from water.However,nonspecific effects of ion exchange groups continue to be a major obstacle for emergency treatment with coexisting ions of high concentrations.The selectivity for Cs+enables zirconium phosphate(ZrP)to be the most promising inorganic sorbent for radioactive cesium extraction,despite being difficult to synthesize and causing excessive pressure loss in fixed-bed reactors due to fine powder.Herein,through facile confined crystallization in host macropores,we prepared PS confinedα-ZrP nanocrystalline(ZrP-PS).Size-screen sorption of layeredα-ZrP and sulfonic acid group preconcentration of PS synergistically enable a considerably higher Cs+affinity of ZrP-PS than PS,as confirmed by X-ray photoelectron spectroscopy(XPS)analysis.ZrP-PS demonstrated remarkable cesium sequestration performance in both batch and continuous experiments,with a high adsorption capacity of 269.58 mg/g,a rapid equilibrium within 80 min,and a continuous effluent volume of 2300 L/kg sorbents.Given the excellent selectivity for Cs+and flexibility to separate from treated water,ZrP-PS holds great promise as purification packages for the emergency treatment of radioactively contaminated water.展开更多
Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge loading.In this paper,t...Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge loading.In this paper,the failure mode and the earth pressure acting on the rigid retaining wall with EPS geofoam inclusions and granular backfills(henceforth referred to as EPS-wall),under limited surcharge loading are investigated through two-and three-dimensional model tests.The testing results show that different from the sliding of almost all the backfill in the EPS-wall under semi-infinite surcharge loading,only an approximately triangular backfill slides in the wall under limited surcharge loading.The distribution of the lateral earth pressure on the EPS-wall under limited surcharge loading is non-linear,and the distribution changes from the increase of the wall depth to the decrease with the increase of the limited surcharge loading.An approach based on the force equilibrium of a differential element is developed to predict the lateral earth pressure behind the EPS-wall subjected to limited surcharge loading,and its performance was fully validated by the three-dimensional model tests.展开更多
Thermoplastics flammability remains a considerable threat during fire incidents.Conventionally,halogen-free fire retardant(FR)additives are incorporated into thermoplastics to reduce fire hazards.However,the incorpora...Thermoplastics flammability remains a considerable threat during fire incidents.Conventionally,halogen-free fire retardant(FR)additives are incorporated into thermoplastics to reduce fire hazards.However,the incorporation of FR additives compromises the mechanical properties(most notably,toughness)of thermoplastics,which has impeded the development of thermoplastic products that possess both high mechanical and fire retarding performances.This study reports an in situ nano-fibrillation strategy to fabricate thermoplastics that exhibit fire retarding properties and a combination of high stiffness and toughness.The proposed composites were composed of in situ thermoplastic polyester elastomer(SBC)nanofibers within a polystyrene(PS)matrix containing hexagonal boron nitride(hBN)as the FR additive.The presence of elastomeric nanofibers successfully mitigated the losses in mechanical performances caused by the incorporation of 2 wt%hBN.Specifically,the inclusion of 15 wt%SBC nanofibers significantly enhanced the toughness of the PS-hBN composite by 350%with negligible effects on the stiffness as compared to neat PS.Furthermore,the presence of nanofibers resulted in synergies with hBN to fabricate composites with enhanced fire retarding performance since the total heat release(THR)of PS-hBN composite decreased from 212 to 189 MJ m^(-2) with 10 wt%nanofibers.Thus,nanofibers behave as a multifunctional component that compensated for the losses in mechanical performances caused by hBN incorporation,while enhancing the fire retarding performance.This strategy can be effectively implemented to fabricate the next generation of polymer composites with high fire retarding and mechanical properties for various applications including energy storage packs for batteries and electronics.展开更多
Microplastics(MPs)are commonly found with hydrophobic contaminants in the water column and pose a serious threat to aquatic organisms.The effects of polystyrene microplastics of different particle sizes on the accumul...Microplastics(MPs)are commonly found with hydrophobic contaminants in the water column and pose a serious threat to aquatic organisms.The effects of polystyrene microplastics of different particle sizes on the accumulation of triclosan in the gut of Xenopus tropicalis,its toxic effects,and the transmission of resistance genes were evaluated.The results showed that co-exposure to polystyrene(PS-MPs)adsorbed with triclosan(TCS)caused the accumulation of triclosan in the intestine with the following accumulation capacity:TCS+5μm PS group>TCS group>TCS+20μm PS group>TCS+0.1μm PS group.All experimental groups showed increased intestinal inflammation and antioxidant enzyme activity after 28 days of exposure to PS-MPs and TCS of different particle sizes.The TCS+20μm PS group exhibited the highest upregulated expression of pro-inflammatory factors(IL-10,IL-1β).The TCS+20μm group showed the highest increase in enzyme activity compared to the control group.PS-MPs and TCS,either alone or together,altered the composition of the intestinal microbial community.In addition,the presence of more antibiotic resistance genes than triclosan resistance genes significantly increased the expression of tetracycline resistance and sulfonamide resistance genes,which may be associated with the development of intestinal inflammation and oxidative stress.This study refines the aquatic ecotoxicity assessment of TCS adsorbed by MPs and provides informative information for the management and control of microplastics and non-antibiotic bacterial inhibitors.展开更多
The environmental behavior of and risks associated with nanoplastics(NPs)have attracted considerable attention.However,compared to pristine NPs,environmental factors such as ultraviolet(UV)irradiation that lead to cha...The environmental behavior of and risks associated with nanoplastics(NPs)have attracted considerable attention.However,compared to pristine NPs,environmental factors such as ultraviolet(UV)irradiation that lead to changes in the toxicity of NPs have rarely been studied.We evaluated the changes in morphology and physicochemical properties of polystyrene(PS)NPs before and after UV irradiation,and compared their hepatotoxicity in mice.The results showed that UV irradiation caused particle size reduction and increased the carbonyl index(CI)and negative charge on the particle surface.UV-aged PS NPs(aPS NPs)could induce the generation of hydroxyl radicals(·OH),but also further promoted the generation of·OH in the Fenton reaction system.Hepatic pathological damage was more severe in mice exposed to aPS NPs,accompanied by a large number of vacuoles and hepatocyte balloon-like changes and more marked perturbations in blood glucose and serum lipoprotein,alanine aminotransferase and aspartate aminotransferase levels.In addition,exposure to PS NPs and aPS NPs,especially aPS NPs,triggered oxidative stress and significantly damaged the antioxidant capacity of mice liver.Compared with PS NPs,exposure to aPS NPs increased the number of altered metabolites in hepatic and corresponding metabolic pathways,especially glutathione metabolism.Our research suggests that UV irradiation can disrupt the redox balance in organisms by promoting the production of·OH,enhancing PS NPs-induced liver damage and metabolic disorders.This study will help us understand the health risks of NPs and to avoid underestimation of the risks of NPs in nature.展开更多
文摘A number of chlorumethylated polystyrenes were synthesized and tried to immobilize aminoacylase from Aspergillus oryzae and many factors which affected immobilized enzyme activity were studied in detail. The results indicated that the immobilized enzyme on support(IAR-1) possessed high enzymatic activity and high stability.
基金supported by the National Natural Science Foundation of China (Nos.20374008 and 20674006).
文摘A study has been conducted on the synthesis and characterization of a kind of novel polyrotaxanes comprisingα- cyclodextrins (α-CDs) threaded on triblock eopolymers with poly(ethylene glycol) (PEG) as a central axle and flanked by two low molecular weight polystyrenes as outer stoppers.Styrene was allowed to telomerize with polypseudorotaxanes as chain transfer agents made from the self-assembly of a distal thiol-capped PEG with a varying amount ofα-CDs in the presence of a redox initiation system at 40~C i...
基金supported by the Institute for Basic Science (IBS-R022-D1)Global Learning&Academic Research Institution for Master’s/Ph D students and Post-Doc Program of the National Research Foundation of Korea Grant funded by the Ministry of Education (RS-2023-00301938)+1 种基金National Research Foundation of Korea Grant funded by the Korean government (RS-2024-00406152,MSIT)Additional financial support was provided by the 2024 Post-Doc Development Program of Pusan National University,Korea Medical Institute,and KREONET。
文摘Polystyrene nanoparticles pose significant toxicological risks to aquatic ecosystems,yet their impact on zebrafish(Danio rerio)embryonic development,particularly erythropoiesis,remains underexplored.This study used single-cell RNA sequencing to comprehensively evaluate the effects of polystyrene nanoparticle exposure on erythropoiesis in zebrafish embryos.In vivo validation experiments corroborated the transcriptomic findings,revealing that polystyrene nanoparticle exposure disrupted erythrocyte differentiation,as evidenced by the decrease in mature erythrocytes and concomitant increase in immature erythrocytes.Additionally,impaired heme synthesis further contributed to the diminished erythrocyte population.These findings underscore the toxic effects of polystyrene nanoparticles on hematopoietic processes,highlighting their potential to compromise organismal health in aquatic environments.
基金supported by the National Natural Science Foundation of China(22308006 and 22278001)the Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0407).
文摘Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectroscopy,thermogravimetric(TG)analysis,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state^(13)C nuclear magnetic resonance spectroscopy.The crucible coal-blending coking tests were carried out using an industrial coal mixture and the treated-PS with the highest caking index(PS300)or raw PS.Some properties of the resultant cokes were also analyzed.It was demonstrated that the caking index of PS dramatically increased by LTPT;however,exceeding 300℃ did not yield any benefit.The caking index increased due to the formation of the caking components,whose molecules are medium in size,caused by LTPT.Additionally,the coke reactivity index of the coke obtained from the mixture containing PS300 decreased by 5.1%relative to that of the coke made from the mixture with PS and the coke strength after reaction index of the former increased by 7.3% compared with that of the latter,suggesting that the ratio of depolymerized PS used for coal-blending coking could increase relative to that of PS.
基金supported by the National Natural Science Foundation of China(No.12027813)the fund of National Innovation Center of Radiation Application of China(Nos.KFZC2020020501,KFZC2021010101).
文摘Polymethyl methacrylate(PMMA)is an optically transparent thermoplastic with favorable processing conditions.In this study,a series of plastic scintillators are prepared via thermal polymerization,and the impact of PMMA content on their transparency and pulse shape discrimination(PSD)ability is investigated.The fabricated samples,comprising a polystyrene(PS)-PMMA matrix,30.0 wt%2,5-diphenyloxazole(PPO),and 0.2 wt%9,10-diphenylanthracene(DPA),exhibit high transparency with transmissivity ranging from 70.0 to 90.0%(above 415.0 nm)and demonstrate excellent n/γdiscrimination capability.Transparency increased with increasing PMMA content across the entire visible light spectrum.However,the PSD performance gradually deteriorated when the aromatic matrix was replaced with PMMA.The scintillator containing 20.0 wt%PMMA demonstrated the best stability concerning PSD properties and relative light yields.
基金Supported by the Program of Sustainable Development and Protection of Artemia Resources in Yuncheng Salt Lake of China(No.YHYJ-2023005)。
文摘Microplastics(MPs)are one of the most concerning pollutants that affects the health and growth of aquatic organisms.We characterized the MPs dispersion in the milli-Q water and seawater,and evaluated the effects of MPs on the gut epithelial cells of brine shrimp using three sizes of polystyrene(PS)microbeads(0.05,0.5,and 5μm,respectively).Results show that microbeads evenly dispersed in milli-Q water,but exhibited aggregation tendency in seawater associating with the particle size.Apart from a reduced survival rate,we observed the structure changes in the gut epithelium that the smaller size of PS microbeads resulted in an increased reactive oxygen species(ROS)and higher apoptosis-related genes expression.Moreover,exposure to all size of PS microbeads led to increased green fluorescence of J-monomer,indicating the declined mitochondrial membrane potential.Therefore,exposure to PS microbeads led to significantly size-dependent toxicity on brine shrimp.Especially,0.05-μm PS microbeads were more toxic,leading to severe oxidative stress and activation of the p53-Bax-Bcl2 pathway,ultimately resulting in cellular apoptosis and gut damage.These findings are important to understand the mechanism of MPs toxicity and its potential ecological risks to marine aquatic animals.
基金supported by Science&Technology Department of Sichuan Province(No.2023YFS0389)Chengdu Technology Innovation Research and Development Project of Chengdu Science and Technology Bureau(No.2022-YF05-00307-SN).
文摘Nanoplastics exhibit greater environmental biotoxicity than microplastics and can be ingested by humans through major routes such as tap water,bottled water and other drinking water.Nanoplastics present a challenge for air flotation due to their minute particle size,negative surface potential,and similar density to water.This study employed dodecyltrimethylammonium chloride(DTAC)as a modifier to improve conventional air flotation,which significantly enhanced the removal of polystyrene nanoplastics(PSNPs).Conventional air flotation removed only 3.09%of PSNPs,while air flotation modified by dodecyltrimethylammonium chloride(DTAC-modified air flotation)increased the removal of PSNPs to 98.05%.The analysis of the DTAC-modified air flotation mechanism was conducted using a combination of instruments,including a zeta potential analyzer,contact angle meter,laser particle size meter,high definition camera,scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and Fourier transform infrared spectrometer(FTIR).The results indicated that the incorporation of DTAC reversed the electrostatic repulsion between bubbles and PSNPs to electrostatic attraction,significantly enhancing the hydrophobic force in the system.This,in turn,improved the collision adhesion effect between bubbles and PSNPs.The experimental results indicated that even when the flotation time was reduced to 7min,the DTACmodified air flotation still achieved a high removal rate of 96.26%.Furthermore,changes in aeration,pH,and ionic strength did not significantly affect the performance of the modified air flotation for the removal of PSNPs.The removal rate of PSNPs in all three water bodies exceeded 95%.The DTAC-modified air flotation has excellent resistance to interference from complex conditions and shows great potential for practical application.
基金financially supported by the National Natural Science Foundation of China(Nos.22172028,21903015,and 22403017)Natural Science Foundation of Fujian Province of China(No.2022J05041)。
文摘Compatibilization is crucial for the blending of immiscible polymers to develop high-performance composites;however,traditional compatibilization by copolymers(pre-made or in-situ generation)suffers from weak interface anchoring,and inorganic particles have gained extensive attention recently owing to their large interfacial desorption energy,while their low affinity to bulk components is a drawback.In this study,an interfacial atom transfer radical polymerization(ATRP)technique was employed to grow polystyrene(PS)and poly(2-hydroxyethyl methacrylate)(PHEMA)simultaneously on different hemispheres of Br-functionalized SiO_(2) nanoparticles to stabilize a Pickering emulsion,whereby a brush-type Janus nanoparticle(SiO_(2)@JNP)was developed.The polymer brushes were well-characterized,and the Janus feature was validated by transmission electron microscope(TEM)observation of the sole hemisphere grafting of SiO_(2)-PS as a control sample.SiO_(2)@JNP was demonstrated to be an efficient compatibilizer for a PS/poly(methyl methacrylate)(PMMA)immiscible blend,and the droplet-matrix morphology was significantly refined.The mechanical strength and toughness of the blend were synchronously enhanced at a low content SiO_(2)@JNP optimized~0.9 wt%,with the tensile strength,elongation at break and impact strength increased by 17.7%,26.6%and 19.6%,respectively.This enhancement may be attributed to the entanglements between the grafted polymer brushes and individual components that improve the particle-bulk phase affinity and enforce interfacial adhesion.
基金Supported by the Pioneer and Leading Goose R&D Program of Zhejiang(No.2023C03130)the National Key R&D Program of China(No.2019YFD0901101)+4 种基金the National Natural Science Foundation of China(No.42076169)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(Nos.SL2022ZD203,SL2022MS012)the Zhejiang Provincial Natural Science Founds for Distinguished Young Scientists(No.LR21D060001)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the ChinaAPEC Cooperation Fund(No.2029901)。
文摘Microplastics(MPs)have garnered significant international scrutiny as an emerging environmental pollutant,constituting one of the four principal global environmental threats and posing potential health hazards to humans.However,data on the impact of MPs on the early life of the commercially important fish remain limited.In this study,polystyrene microspheres(PS-MPs)(1 and 5μm)were used to investigate the effects of MPs on the growth,development,and metabolism in early life stages of large yellow croaker Pseudosciaena crocea.Results indicate that MPs were enriched in the gastrointestinal tract and gills of the fish.In addition,PS-MPs(1μm)exhibited no obvious effects on embryo hatching and heart rates,while increased the mortality rate(23.00%vs.control 14.99%)and decreased the body length(4098.61±447.03μm vs.control with 2827.04±254.75μm)of the larvae at the highest exposure concentration(5×10^(4)items/L).Metabolomics analysis revealed that PS-MPs(5μm)induced mild perturbations in phospholipid metabolism,specifically alterations in phosphatidylethanolamine(PE)levels.These changes influenced the cell membranes of juvenile fish,and consequently elicited inflammatory responses,disrupted lipid homeostasis,and affected other critical physiological processes.Ultimately,these effects may avoid the growth retardation and potential mortality.Therefore,PS-MPs could affect negatively the fish health in the early life stage,which has implications for aquatic ecosystems.
文摘The process of disposing of expanded polystyrene (EPS) is by burning it in municipal incinerators. This process gives off EPS microplastics, which can find their way into water, food, blood, and major organ systems. Zophobas morio larvae are capable of consuming and breaking down EPS within their digestive tracts by minimizing the spread of microplastics. Studies of the consumption of EPS by Z. morio larvae are typically conducted under white or no visible light treatments. This study tested whether the color of visible light influenced the consumption rate of EPS by Z. morio larvae. If Z. morio larvae consume EPS under visible light, then visible light will influence the amount of EPS consumed. If results suggest that the consumption rate is influenced by visible light colors, then Z. morio larvae could be a solution for recycling EPS. This study’s procedure placed Z. morio larvae into 25 jars under one of six visible light treatments of red, yellow, green, blue, white, and no visible light. Each jar contained a pre-weighed block of EPS and six Z. morio larvae. After two weeks, the Z. morio larvae were removed from the jars, and the difference between each pre-weighed EPS block and the weight of the same partially consumed block was recorded in three trials. The data indicates that green and blue visible light treatments resulted in the greatest amount of EPS consumed by Z. morio larvae while the red and yellow had the least amount of EPS consumed by the Z. morio larvae. In conclusion, results indicate that green and blue visible light, compared to the no visible light treatment, could be used to influence the Z. morio larvae to consume more EPS. Green and blue visible light and Z. morio larvae could make the recycling process of EPS more environmentally friendly when used in households or by local environmental organizations.
基金financially supported by the National Natural Science Foundation of China(No.52074204)Key R&D Program of Zhejiang Province,China(No.2022C03061)。
文摘The adsorption kinetics of polystyrene[1-butyl-3-methylimidazolium][bis(2,4,4-trimethylpentyl)phosphinate](PS[C_(4)mim][C272])towards V(V)in acidic leachate was explored under ultrasound.The effects of ultrasonic power and V(V)concentration on the adsorption performance of PS[C_(4)mim][C272]were investigated.The results showed that ultrasonic radiation significantly shortened the adsorption equilibrium time and improved the adsorption performance of PS[C_(4)mim][C272]compared with the conventional oscillation.At an ultrasonic power of 200 W,the equilibrium adsorption capacity of PS[C_(4)mim][C272]reached its maximum of 311.58 mg/g.The kinetic model fitting results showed that the adsorption process of PS[C_(4)mim][C272]strictly followed the pseudo-second-order kinetic model under ultrasound.Analysis using the shrinking core model and the Weber−Morris model showed that the adsorption process of PS[C_(4)mim][C272]was primarily controlled by intra-particle diffusion mechanism.The adsorption isotherm model study showed that the Langmuir isotherm model could effectively fit the adsorption process of PS[C_(4)mim][C272]under ultrasound.
基金Thanks for financial support from the National Natural Science Foun-dation of China(No.51906252)the Natural Science Foundation of Jiangsu Province(NO.BK20190632)China Postdoctoral Science Foun-dation(2019M661980).
文摘Polystyrene(PS)is rich in plastic materials,but it produces a large amount of waste every year,causing a huge burden on the environment.Although PS plastic is the source of a common"white pollution"in daily life,it still has a high utilization value.At the same time,the flammability of PS material determines that it cannot be applicated in places where fire accidents occur frequently.As a result,its application has been greatly limited.In order to realize the efficient utilization of waste PS and broaden its scope of application,PS was modified by hyper-crosslinking in order to improve its fire-retardant performance.In this method,the PS solution with high purity was obtained by dissolving waste PS foam with 1,2-dichloroethane(DCE),and then the hyper-crosslinked polymer with high specific surface area was prepared by adding cross-linking agent formaldehyde dimethyl acetal(FDA)and a Lewis-acid catalyst ferric chloride(FeCl_(3)).Further studies showed that the effects of the amount of cross-linking agent FDA,catalyst FeCl_(3) and PS on the reaction products were different.In addition,compared the as-prepared fire-retardant materials with PS foam from the aspects of flame retardancy and thermal insulation,it can be concluded that the fire-retardant performance of the materials prepared by this method has been significantly enhanced.And it is proved that this method is feasible towards the preparation of a large number of fire-retardant composite materials by using a scale-up experiment.
基金financially supported by the project of the National Natural Science Foundation of China (Grant Nos.51972270,52322203)the Key Research and Development Program of Shaanxi Province (Grant NO.2024GH-ZDXM-21)the Fundamental Research Funds for the Central Universities (Grant Nos.G2022KY0607,23GH0202277).
文摘Exploiting high-performance yet low-cost hard carbon anodes is crucial to advancing the state-of-the-art sodium-ion batteries.However,the achievement of superior initial Coulombic efficiency(ICE)and high Na-storage capacity via low-temperature carbonization remains challenging due to the presence of tremendous defects with few closed pores.Here,a facile hybrid carbon framework design is proposed from the polystyrene precursor bearing distinct molecular bridges at a low pyrolysis temperature of 800℃ via in situ fusion and embedding strategy.This is realized by integrating triazine-and carbonylcrosslinked polystyrene nanospheres during carbonization.The triazine crosslinking allows in situ fusion of spheres into layered carbon with low defects and abundant closed pores,which serves as a matrix for embedding the well-retained carbon spheres with nanopores/defects derived from carbonyl crosslinking.Therefore,the hybrid hard carbon with intimate interface showcases synergistic Na ions storage behavior,showing an ICE of 70.2%,a high capacity of 279.3 mAh g^(-1),and long-term 500 cycles,superior to carbons from the respective precursor and other reported carbons fabricated under the low carbonization temperature.The present protocol opens new avenues toward low-cost hard carbon anode materials for high-performance sodiumion batteries.
基金This work was supported by the Key Projects of Natural Science Foundation of Heilongjiang Province of China(No.ZD2020C005).
文摘Microplastics(MPs)have attracted growing attention worldwide as an increasingly prevalent environmental pollutant.In addition,chicken meat is currently the most widely consumed kind of poultry in the global market.Consumer demand for chicken is on the rise both at home and abroad.As a result,the safety of chicken raising has also received significant attention.The lungs play an essential role in the physiological activities of chickens,and they are also the most vulnerable organs.Lung injury is difficult to repair after the accumulation of contaminants,and the mortality rate is high,which brings huge economic losses to farmers.The research on the toxicity of MPs has mainly focused on the marine ecosystem,while the mechanisms of toxicity and lung damage in chickens have been poorly studied.Thus,this study explored the effects of exposure to polystyrene microplastics(PS-MPs)at various concentrations for 42 d on chicken lungs.PS-MPs could cause lung pathologies and ultrastructural abnormalities,such as endoplasmic reticulum(ER)swelling,inflammatory cell infiltration,chromatin agglutination,and plasma membrane rupture.Simultaneously,PS-MPs increased the expression of genes related to the heat shock protein family(Hsp60,Hsp70,and Hsp90),ER stress signaling(activating) transcription factor 6(ATF0),ATF4,protein kinase RNA-like ER kinase(PERK),and eukaryotic translation initiation factor 2 subunitα(eIF2a),pyroptosis-related genes(NOD)-,LRR-and pyrin domain-containing protein 3(NLRP3),apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),interleukin-1β(IL-1β),cysteinyl aspartate-specific proteinase 1(Caspasel),and gasdermin-D(GSDMD),and the inflammatory signaling pathway(nuclear factor-kB(NF-kB),inducible nitric oxide synthase(iNOS),and cyclooxygenase-2(COX-2).The above results showed that PS-MP exposure could result in lung stress,ER stress,pyroptosis,and inflammation in broilers.Our findings provide new scientific clues for further research on the mechanisms of physical health and toxicology regardingMPs.
基金supported by the Basic Study and Interdisciplinary R&D Foundation of the University of Seoul(2019)grants,Nos.201910021035202006251003(both to KYR and JC)。
文摘Many types of plastic products,including polystyrene,have long been used in commercial and industrial applications.Microplastics and nanoplastics,plastic particles derived from these plastic products,are emerging as environmental pollutants that can pose health risks to a wide variety of living organisms,including humans.However,it is not well understood how microplastics and nanoplastics affect cellular functions and induce stress responses.Humans can be exposed to polystyrene-microplastics and polystyrene-nanoplastics through ingestion,inhalation,or skin contact.Most ingested plastics are excreted from the body,but inhaled plastics may accumulate in the lungs and can even reach the brain via the nose-to-brain route.Small-sized polystyrene-nanoplastics can enter cells by endocytosis,accumulate in the cytoplasm,and cause various cellular stresses,such as inflammation with increased pro-inflammatory cytokine production,oxidative stress with generation of reactive oxygen species,and mitochondrial dysfunction.They induce autophagy activation and autophagosome formation,but autophagic flux may be impaired due to lysosomal dysfunction.Unless permanently exposed to polystyrene-nanoplastics,they can be removed from cells by exocytosis and subsequently restore cellular function.However,neurons are very susceptible to this type of stress,thus even acute exposure can lead to neurodegeneration without recovery.This review focuses specifically on recent advances in research on polystyrene-nanoplastic-induced cytotoxicity and neurotoxicity.Furthermore,in this review,based on mechanistic studies of polystyrene-nanoplastics at the cellular level other than neurons,future directions for overcoming the negative effects of polystyrene-nanoplastics on neurons were suggested.
基金NSFC(Nos.U22A20403,21301151 and 52070115)Natural Science Foundation of Hebei Province(Nos.B2021203036 and E2022203011)Key Project of the Hebei Education Department(No.ZD2021103).
文摘Polystyrene resins(PS)have been practical ion exchangers for radionuclides removal from water.However,nonspecific effects of ion exchange groups continue to be a major obstacle for emergency treatment with coexisting ions of high concentrations.The selectivity for Cs+enables zirconium phosphate(ZrP)to be the most promising inorganic sorbent for radioactive cesium extraction,despite being difficult to synthesize and causing excessive pressure loss in fixed-bed reactors due to fine powder.Herein,through facile confined crystallization in host macropores,we prepared PS confinedα-ZrP nanocrystalline(ZrP-PS).Size-screen sorption of layeredα-ZrP and sulfonic acid group preconcentration of PS synergistically enable a considerably higher Cs+affinity of ZrP-PS than PS,as confirmed by X-ray photoelectron spectroscopy(XPS)analysis.ZrP-PS demonstrated remarkable cesium sequestration performance in both batch and continuous experiments,with a high adsorption capacity of 269.58 mg/g,a rapid equilibrium within 80 min,and a continuous effluent volume of 2300 L/kg sorbents.Given the excellent selectivity for Cs+and flexibility to separate from treated water,ZrP-PS holds great promise as purification packages for the emergency treatment of radioactively contaminated water.
基金funding support from National Natural Science Foundation of China(Grant No.52179109)Jiangsu Provincial Natural Science Foundation(Grant No.BK20230967)Open Research Fund of State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University(Grant No.KF2022-02).
文摘Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge loading.In this paper,the failure mode and the earth pressure acting on the rigid retaining wall with EPS geofoam inclusions and granular backfills(henceforth referred to as EPS-wall),under limited surcharge loading are investigated through two-and three-dimensional model tests.The testing results show that different from the sliding of almost all the backfill in the EPS-wall under semi-infinite surcharge loading,only an approximately triangular backfill slides in the wall under limited surcharge loading.The distribution of the lateral earth pressure on the EPS-wall under limited surcharge loading is non-linear,and the distribution changes from the increase of the wall depth to the decrease with the increase of the limited surcharge loading.An approach based on the force equilibrium of a differential element is developed to predict the lateral earth pressure behind the EPS-wall subjected to limited surcharge loading,and its performance was fully validated by the three-dimensional model tests.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)DG(No.RGPIN-2015-03985)the Ontario Research Fund(No.ORF-RE 07)。
文摘Thermoplastics flammability remains a considerable threat during fire incidents.Conventionally,halogen-free fire retardant(FR)additives are incorporated into thermoplastics to reduce fire hazards.However,the incorporation of FR additives compromises the mechanical properties(most notably,toughness)of thermoplastics,which has impeded the development of thermoplastic products that possess both high mechanical and fire retarding performances.This study reports an in situ nano-fibrillation strategy to fabricate thermoplastics that exhibit fire retarding properties and a combination of high stiffness and toughness.The proposed composites were composed of in situ thermoplastic polyester elastomer(SBC)nanofibers within a polystyrene(PS)matrix containing hexagonal boron nitride(hBN)as the FR additive.The presence of elastomeric nanofibers successfully mitigated the losses in mechanical performances caused by the incorporation of 2 wt%hBN.Specifically,the inclusion of 15 wt%SBC nanofibers significantly enhanced the toughness of the PS-hBN composite by 350%with negligible effects on the stiffness as compared to neat PS.Furthermore,the presence of nanofibers resulted in synergies with hBN to fabricate composites with enhanced fire retarding performance since the total heat release(THR)of PS-hBN composite decreased from 212 to 189 MJ m^(-2) with 10 wt%nanofibers.Thus,nanofibers behave as a multifunctional component that compensated for the losses in mechanical performances caused by hBN incorporation,while enhancing the fire retarding performance.This strategy can be effectively implemented to fabricate the next generation of polymer composites with high fire retarding and mechanical properties for various applications including energy storage packs for batteries and electronics.
基金supported by the National Natural Science Foundation of China(Nos.31802025,41977340,and 42277260).
文摘Microplastics(MPs)are commonly found with hydrophobic contaminants in the water column and pose a serious threat to aquatic organisms.The effects of polystyrene microplastics of different particle sizes on the accumulation of triclosan in the gut of Xenopus tropicalis,its toxic effects,and the transmission of resistance genes were evaluated.The results showed that co-exposure to polystyrene(PS-MPs)adsorbed with triclosan(TCS)caused the accumulation of triclosan in the intestine with the following accumulation capacity:TCS+5μm PS group>TCS group>TCS+20μm PS group>TCS+0.1μm PS group.All experimental groups showed increased intestinal inflammation and antioxidant enzyme activity after 28 days of exposure to PS-MPs and TCS of different particle sizes.The TCS+20μm PS group exhibited the highest upregulated expression of pro-inflammatory factors(IL-10,IL-1β).The TCS+20μm group showed the highest increase in enzyme activity compared to the control group.PS-MPs and TCS,either alone or together,altered the composition of the intestinal microbial community.In addition,the presence of more antibiotic resistance genes than triclosan resistance genes significantly increased the expression of tetracycline resistance and sulfonamide resistance genes,which may be associated with the development of intestinal inflammation and oxidative stress.This study refines the aquatic ecotoxicity assessment of TCS adsorbed by MPs and provides informative information for the management and control of microplastics and non-antibiotic bacterial inhibitors.
基金supported by the National Natural Science Foundation of China(Nos.82173569,81872667)。
文摘The environmental behavior of and risks associated with nanoplastics(NPs)have attracted considerable attention.However,compared to pristine NPs,environmental factors such as ultraviolet(UV)irradiation that lead to changes in the toxicity of NPs have rarely been studied.We evaluated the changes in morphology and physicochemical properties of polystyrene(PS)NPs before and after UV irradiation,and compared their hepatotoxicity in mice.The results showed that UV irradiation caused particle size reduction and increased the carbonyl index(CI)and negative charge on the particle surface.UV-aged PS NPs(aPS NPs)could induce the generation of hydroxyl radicals(·OH),but also further promoted the generation of·OH in the Fenton reaction system.Hepatic pathological damage was more severe in mice exposed to aPS NPs,accompanied by a large number of vacuoles and hepatocyte balloon-like changes and more marked perturbations in blood glucose and serum lipoprotein,alanine aminotransferase and aspartate aminotransferase levels.In addition,exposure to PS NPs and aPS NPs,especially aPS NPs,triggered oxidative stress and significantly damaged the antioxidant capacity of mice liver.Compared with PS NPs,exposure to aPS NPs increased the number of altered metabolites in hepatic and corresponding metabolic pathways,especially glutathione metabolism.Our research suggests that UV irradiation can disrupt the redox balance in organisms by promoting the production of·OH,enhancing PS NPs-induced liver damage and metabolic disorders.This study will help us understand the health risks of NPs and to avoid underestimation of the risks of NPs in nature.
