Ocean-degradable polyesters incorporating hydrophilic and rapidly degradable glycolide(GL)units into the polymer chain are the most promising for addressing marine plastic pollution,however,it is challenging to obtain...Ocean-degradable polyesters incorporating hydrophilic and rapidly degradable glycolide(GL)units into the polymer chain are the most promising for addressing marine plastic pollution,however,it is challenging to obtain high-molecular-weight copolymers with narrow molecular weight distributions.Herein,we prepared a novel biodegradable material,poly(butylene succinate-co-glycolide)(PBSGL),through ring-opening copolymerization using glycolide,succinic anhydride,and 1,4-butanediol as raw materials,providing a new solution strategy for marine pollution.GL could be polymerized according to the pre-designed composition by 1H-nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)results,indicating controlled polymerization with the synthesized PBSGLs having a weight-average molecular weight of up to 12.30×10^(4) g/mol and a narrow molecular weight distribution(1.33–1.65).Differential scanning calorimeter(DSC)and thermogravimetric analysis(TGA)results showed that T_(g) of PBSGLs increased from−32.5°C to−26.5°C with the increase of GL content from 0%to 40%,while T_(m)(>76°C)was much lower than T_(d,5%)(>314°C),which indicated that PBSGLs had good thermal stability and expanded the processing window and application range of the original poly(butylene succinate)(PBS)materials.Under simulated difficult conditions,PBSGL copolyesters could degrade faster with increasing GL content,where PBSGL40 degraded by 22.6%in 12 days,showing good biodegradability.Currently,most biodegradable polyesters with good performance slowly degrade in seawater.In a 30-day artificial seawater degradation test,the amorphous PBSGL40 copolyester showed a about 15-fold(2.33%weight loss)improvement in degradation ability compared to pure PBS,demonstrating rapid seawater degradation capability.展开更多
Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardan...Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardant strategies often compromise their mechanical properties,hindering their practical applications.Herein,a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)-based comonomer(DDP)was used to synthesize flame-retardant poly(ethylene furandicarboxylate-co-phosphaphenanthrene)(PEFDn).The covalent integration of DDP confers intrinsic flame retardancy,avoiding the plasticization and migration issues associated with additive-type systems.Upon thermal decomposition,the DOPO-derived moieties release phosphoric acid and radical scavengers,promoting char formation and suppressing flame propagation.Furthermore,density functional theory(DFT)calculations combined with non-covalent interaction(NCI)analysis revealed that DOPO dimer molecules adopt a stable parallel-displaced π-π stacking configu ration,potentially facilitating microphase separation and enhancing the energy dissipation capability.PEFD_(10)achieves a UL-94 V-0 rating while simultaneously increasing impact toughness from 1.5 kJ/m^(2) to 14.7 kJ/m^(2).Im portantly,PEFDn maintained acceptable oxygen-barrier properties.PEFD10 also exhibited high transparency and UV-shielding performance.The combination of intrinsic flame safety,im pact-toughness resistance,UV shielding,and an oxygen barrier ensures reliable protection of electrical components and long-term operational stability.The integration of multiple critical properties within a single bio-based material represents a novel approach fo r enabling sustainable polymer solutions for high-pe rformance electrical applications.展开更多
It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation...It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.展开更多
Most commercial plastics cannot easily degrade,which raises a number of sustainability issues.To address the current problem of plastic pollution,the research and development of easily degradable and recyclable polyme...Most commercial plastics cannot easily degrade,which raises a number of sustainability issues.To address the current problem of plastic pollution,the research and development of easily degradable and recyclable polymers has become an attractive subject.Herein,a new monomer of thiosalicylic methyl glycolide(TSMG)was synthesized using one-pot method and high molecular weight poly(thiosalicylic methyl glycolide)(PTSMG,M_(n) up to 300 kDa)can be obtained via the ring-opening polymerization(ROP)of TSMG.PTSMG exhibits good closed-loop recyclability and hydrolytic degradability,where PTSMG can generate pristine monomers through sublimation thermal depolymerization conditions due to the presence of thiophenol ester bond in the polymer chains,and can be degraded rapidly in aqueous solution,which provides a potential solution to the current plastic pollution problem.展开更多
It is well known that cationic polymers have excellent antimicrobial capacity accompanied with high biotoxicity,to reduce biotoxicity needs to decrease the number of cationic groups on polymers,which will influence an...It is well known that cationic polymers have excellent antimicrobial capacity accompanied with high biotoxicity,to reduce biotoxicity needs to decrease the number of cationic groups on polymers,which will influence antimicrobial activity.It is necessary to design a cationic polymer mimic natural antimicrobial peptide with excellent antibacterial activity and low toxicity to solve the above dilemma.Here,we designed and prepared a series of cationic poly(β-amino ester)s(PBAEs)with different cationic contents,and introducing hydrophobic alkyl chain to adjust the balance between antimicrobial activity and biotoxicity to obtain an ideal antimicrobial polymer.The optimum one of synthesized PBAE(hydrophilic cationic monomer:hydrophobic monomer=5:5)was screened by testing cytotoxicity and minimum inhibitory concentration(MIC),which can effectively kill S.aureus and E.coli with PBAE concentration of15μg/m L by a spread plate bacteriostatic method and dead and alive staining test.The way of PBAE killing bacterial was destroying the membrane like natural antimicrobial peptide observed by scanning electron microscopy(SEM).In addition,PBAE did not exhibit hemolysis and cytotoxicity.In particular,from the result of animal tests,the PBAE was able to promote healing of infected wounds from removing mature S.aureus and E.coli on the surface of infected wound.As a result,our work offers a viable approach for designing antimicrobial materials,highlighting the significant potential of PBAE polymers in the field of biomedical materials.展开更多
Poly(butylene succinate-co-furandicarboxylate)(PBSF)and poly(butylene adipateco-furandicarboxylate)(PBAF)are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived...Poly(butylene succinate-co-furandicarboxylate)(PBSF)and poly(butylene adipateco-furandicarboxylate)(PBAF)are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene succinate-co-terephthalate)(PBST)and poly(butylene adipate-co-terephthalate)(PBAT).In this study,quantum chemistry techniques after molecular dynamics simulations are employed to investigate the degradationmechanism of PBSF and PBAF catalyzed by Candida antarctica lipase B(CALB).Computational analysis indicates that the catalytic reaction follows a four-step mechanism resembling the ping-pong bibi mechanism,with the initial two steps being acylation reactions and the subsequent two being hydrolysis reactions.Notably,the first step of the hydrolysis is identified as the rate-determining step.Moreover,by introducing single-point mutations to expand the substrate entrance tunnel,the catalytic distance of the first acylation step decreases.Additionally,energy barrier of the rate-determining step is decreased in the PBSF system by site-directed mutations on key residues increasing hydrophobicity of the enzyme’s active site.This study unprecedently show the substrate binding pocket and hydrophobicity of the enzyme’s active site have the potential to be engineered to enhance the degradation of copolyesters catalyzed by CALB.展开更多
Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport ...Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport while maintaining the structural stability of the electrode under continuous charge‑discharge cycles.Electrochemical characterization under a three‑electrode system revealed exceptional rate capability:Mn@PN delivered an ultrahigh specific capacitance of 10318 F·g^(-1) at a low current density of 3 A·g^(-1) and retained 9415 F·g^(-1)(91.2%retention compared to the value at 3 A·g^(-1))even at an ultrahigh current density of 50 A·g^(-1).Moreover,the material exhibited 97.4%capacitance retention after 9000 cycles at 30 A·g^(-1),corresponding with a low capacitance decay rate of 0.003‰per cycle,significantly outperforming conventional conductive polymers like polyaniline(PANI).An asymmetric supercapacitor assembled with Mn@PN as the positive electrode(Mn@PN||AC)achieved an energy density of 328 Wh·kg^(-1) at 15 A·g^(-1) and retained 80.7%of its initial specific capacitance after 4000 cycles at 20 A·g^(-1).展开更多
In this study,a series of poly(ethylene succinate)-b-poly(butylene carbonate)(PES-b-PBC)multiblock copolymers were prepared through the chain-extension reaction of hydroxyl-terminated PES(PES-OH)and hydroxyl-terminate...In this study,a series of poly(ethylene succinate)-b-poly(butylene carbonate)(PES-b-PBC)multiblock copolymers were prepared through the chain-extension reaction of hydroxyl-terminated PES(PES-OH)and hydroxyl-terminated PBC(PBC-OH)prepolymers with 1,6-hexmethylene diisocyanate(HDI)as a chain extender.The effects of the prepolymer molecular weight and content on the structure and application properties of the PES-b-PBC copolymers were systematically investigated using various techniques.It was found that the compatibility of PES and PBC blocks in PES-b-PBC copolymers can be greatly enhanced by lowering the length of the prepolymers,and the amorphous phase of the PES and PBC chain segments in the PES-b-PBC copolymer would transform from immiscibility and partial miscibility to miscibility when the number-average molecular weight(M_(n))of the PES-OH and PBC-OH prepolymers is less than 2000 g/mol.Only the crystal structure of bare PES can be observed in the wide-angle X-ray diffraction(WAXD)spectrum of the PES-b-PBC copolymers,but their crystallinity degrees were found to decrease with increasing PBC fraction.The thermal behavior,crystallization performance,rheological properties,mechanical properties,and degradation properties of the PES-b-PBC multiblock copolymers can be easily modulated by altering the block length and composition of the prepolymers,offering potential applications in biodegradable materials.展开更多
Poly(ethylene succinate)(PES),a promising biodegradable polyester with cost advantages,suffers from inherently slow crystallization kinetics,which severely limits its processability and practical applications.To addre...Poly(ethylene succinate)(PES),a promising biodegradable polyester with cost advantages,suffers from inherently slow crystallization kinetics,which severely limits its processability and practical applications.To address this challenge,this study explored the use of commercially available,low-cost,and food-safe sugar alcohols,including Xylitol(Xy),D-sorbitol(DS),and D-mannitol(DM),as effective nucleating agents for PES.Remarkably,all three polyols significantly enhanced the nucleation and crystallization ability of PES,with DM exhibiting the most pronounced effect.DM increased the crystallization temperature by up to 23.9°C and accelerated the overall crystallization rate by more than 13-fold at only 0.5 wt%loading level.Through a combination of differential scanning calorimetry(DSC),polarized optical microscopy(POM),and wide-angle X-ray diffraction(WAXD)analyses,we revealed that DM promotes PES crystallization via a dual mechanism:epitaxial templating facilitated by excellent lattice matching,and enhanced chain adjustment through intermolecular hydrogen-bonding interactions.In contrast,Xy and DS primarily function through hydrogen-bonding interactions.This work not only identifies DM as a highly efficient,economical,and industrially viable nucleating agent for PES,but also provides fundamental insights into the role of the molecular structure and crystallization ability of nucleating agents in regulating polymer crystallization.展开更多
Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differenc...Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differences in their crystallization-promoting efficiency,and the underlying mechanism remains unclear.In this study,a series of nucleating agents,including N,N-diphenylterephthalamide(DPTA),N,N,N-triphenyl-1,3,5-benzenetricarboxamide(TPTA),N,N-diphenyl terephthalohydrazide(DBTA),and N,N,N-tribenzoyl-1,3,5-benzenetricarbohydrazide(TBTA),were designed and synthesized to investigate the differences in their effects on the crystallization performance of PLA.Density functional theory(DFT)and molecular dynamics(MD)simulations showed that DBTA had a smaller electrostatic potential difference(66.2 kcal/mol).During the cooling process,DBTA could stably form more intermolecular hydrogen bonds with PLA and exhibit a higher interaction energy,thus theoretically enabling more efficient promotion of PLA crystallization.Further differential scanning calorimetry(DSC)results revealed that at a 0.5wt%loading of DBTA,the crystallization peak temperature of the PLA-DBTA composite reached 118.1℃during cooling,whereas no distinct crystallization peak was observed for pure PLA under identical conditions.The crystallinity of the composite was significantly increased to 58.4%compared to 14.6%of pure PLA.Moreover,under isothermal crystallization at 130℃,DBTA reduced the half-crystallization time of PLA to 2.9min,while the half-crystallization time for pure PLA was 27.4 min.Time-resolved Fourier transform infrared spectroscopy(FTIR)results also confirmed that DBTA promoted the formation of gt conformational isomers of PLA during the crystallization process.This study elucidates the mechanism behind the performance differences between structurally similar nucleating agents in regulating PLA crystallization from the perspective of molecular electrostatic potential and hydrogen bonding interactions,providing a theoretical basis for the molecular design of efficient nucleating agents.展开更多
In-situ poly(1,3-dioxolane)(PDOL)-based electrolyte has received extensive attention in the research of lithium metal batteries due to its high stability to lithium anode and simple processing.However,it is still face...In-situ poly(1,3-dioxolane)(PDOL)-based electrolyte has received extensive attention in the research of lithium metal batteries due to its high stability to lithium anode and simple processing.However,it is still faced with defects such as low intrinsic ionic conductivity,a narrow electrochemical window,and poor thermal stability.A crosslinking and fluorination molecular design strategy toward PDOL is proposed to tackle the issues above.The amorphous crosslinked structure effectively improves ionic conductivity by inhibiting long-chain crystallization.Especially,the antioxidant–CF_(3)groups,stable crosslinked structure,and reduced terminal hydroxyl groups significantly enhance the electrochemical oxidation stability with a superb high-voltage window of 4.7 V.In addition,the designed electrolyte also exhibits obviously improved thermal stability with no deformation at 120°C for 5 min.Furthermore,the semi-solid NCM811||Li batteries exhibit a favourable capacity retention of 88.8%after 150 cycles at 0.5 C.Even assembled with NCM622 cathode working at 4.5 V,the semi-solid batteries can still show a satisfactory capacity retention of 85.3%after 100 cycles at 0.5 C.Also,a 0.1 Ah NCM811||Li pouch cell with active materials loading of 9 mg/cm2 demonstrates satisfactory cycling stability and working ability,which shows promising practical application prospects.展开更多
Smart pesticide delivery systems based on stimuli-responsive nanocarriers have attracted considerable attention because of their potential to enhance pesticide efficiency while reducing environmental risks.In this stu...Smart pesticide delivery systems based on stimuli-responsive nanocarriers have attracted considerable attention because of their potential to enhance pesticide efficiency while reducing environmental risks.In this study,a novel p H/glutathione dual-responsive pesticide delivery system was constructed through the synthesis of disulfide-bridged hollow mesoporous organosilica nanospheres(HMONs)via the St??ber method,followed by poly(acrylic acid)(PAA)coating through distillation-precipitation polymerization to form HMONs@PAA nanocomposites.The resulting abamectin-loaded system(Abamectin-HMONs@PAA)demonstrated a 12.73% pesticide loading capacity and significantly improved photostability,retaining twice as much active ingredient as free abamectin after 250 h of UV irradiation(36 W).Release studies revealed p H-and glutathione-dependent characteristics,with cumulative releases in acidic conditions exceeding those in neutral and alkaline environments by 18.66% and 40.98%,respectively,and a 14.2% increase in glutathione-containing solution(0.2 mmol·L^(-1) in 70% ethanol)after 97 h.Bioassays showed superior performance against Plutella xylostella,with a 13.33% reduction in survival rate compared to conventional suspension at equivalent dosage(40 mg·L^(-1)),while maintaining efficacy after extensive rainfall simulation(20 events over 10 days).This study provides a promising approach for developing environmentally responsive nanopesticides with enhanced durability and controlled-release properties,offering significant potential for sustainable crop protection.展开更多
Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its...Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.展开更多
Silica aerogels(SAs)impart low density and excellent thermal insulation to polymer systems,yet incorporating hydrophobic SAs into aqueous rubber latex systems remains challenging owing to their poor dispersibility and...Silica aerogels(SAs)impart low density and excellent thermal insulation to polymer systems,yet incorporating hydrophobic SAs into aqueous rubber latex systems remains challenging owing to their poor dispersibility and potential to destabilize the latex.Although previous studies have dispersed SAs in aqueous poly(vinyl alcohol)(PVA),the stability of such dispersions and their effectiveness as bridging media for latex integration have not been thoroughly evaluated,which limits their practical application in latex compounding.This study systematically examined how the surface chemistry governs hydrolytic stability,interfacial behavior,and latex compatibility in PVA-assisted aqueous processing.Two hydrophobic SAs were prepared:ethoxy-modified SA(E-SA)and methyl-modified SA(M-SA).Both initially formed a homogeneous PVA slurry,but E-SA rapidly hydrolyzed its surface—OCH_(2)CH_(3)groups,releasing ethanol,becoming hydrophilic,and undergoing irreversible nanopore collapse.In contrast,M-SA maintains its structural integrity and hydrophobicity because its—Si(CH_(3))_(3)groups are highly resistant to hydrolysis.This divergence dictates the behavior during latex blending.The ethanol released from E-SA disrupts electrostatic and steric stabilization,inducing latex coagulation,whereas M-SA/PVA dispersions preserve colloidal stability across diverse latex systems.As a practical demonstration,M-SA-reinforced chlorosulfonated polyethylene(CSM)rubber latex composites show more than a 50%reduction in thermal conductivity while maintaining chemical resistance,enabling high-performance insulating protective gloves and coatings.This work establishes a critical link between aerogel surface chemistry and aqueous processing stability,providing a mechanistic foundation for the rational design of water-based rubber/silica aerogel composites and next-generation thermal insulation materials.展开更多
Eukaryotic mRNAs are polyadenylated at their 3’-ends,and the poly(A)tails play critical roles in post-transcriptional gene regulation by influencing mRNA stability and translation.Here,we describe the biological proc...Eukaryotic mRNAs are polyadenylated at their 3’-ends,and the poly(A)tails play critical roles in post-transcriptional gene regulation by influencing mRNA stability and translation.Here,we describe the biological processes and major protein factors that control poly(A)tail synthesis and shortening.We also discuss recent breakthroughs in poly(A)tail sequencing methods that enable high throughput and accurate measurement of poly(A)tail lengths.Finally,we review how poly(A)-tail regulators and poly(A)-tail-mediated post-transcriptional mechanisms affect stem cell fate and early embryonic development.展开更多
Efficient recovery of uranium from radioactive wastewater significantly has far-reaching positive implications for both the recycling of uranium resources and environmental conservation.In this work,a new stable hydro...Efficient recovery of uranium from radioactive wastewater significantly has far-reaching positive implications for both the recycling of uranium resources and environmental conservation.In this work,a new stable hydrogel/MOFs composite with potential for efficient uranium capture has been developed.A double network structure was formed through the chemical covalent crosslinking of poly(acrylamide-acrylic acid) and the physical crosslinking of agar.The rapid self-crosslinking of agar not only enables the uniform dispersion of Metal-Organic Frameworks(MOFs) nanoparticles but also promotes the hydrogel to possess exceptional tensile strength and low swelling ratio,whereas the incorporation of amidoximated MOFs enhances the selectivity for uranium.The composite achieved a uranium-uptake capacity of 275.42 mg/g(298 K,C0=120 mg/L,pH=6),and it retains reproducible and stable after five cycles,while exhibiting high selectivity for uranyl,even amidst ten competing metal ions.Moreover,the uranium removal rate reached 93 % within three days in low concentration simulated nuclear wastewater.Multiple spectral analyses coupled with theoretical calculations confirmed that the mechanism of U(Ⅵ) capture involves intraparticle diffusion,along with the coordination of amidoxime,carboxyl,and amino groups.This research offers a valuable reference for the development of composite materials to treat radioactive effluent.展开更多
This study aimed to systematically regulate the performance of 4D printing composites by investigating the synergistic effects of dicumyl peroxide(DCP)and maleic anhydride-grafted polyethylene(MAH-g-PE)on a poly(lacti...This study aimed to systematically regulate the performance of 4D printing composites by investigating the synergistic effects of dicumyl peroxide(DCP)and maleic anhydride-grafted polyethylene(MAH-g-PE)on a poly(lactic acid)/thermoplastic polyurethane(PLA/TPU)matrix.Specifically,using a 70 wt%/30 wt%PLA/TPU matrix and an L_(9)(3^(2))orthogonal design,composites were evaluated via morphology,shape memory,mechanical tests,and multi-criteria analysis.Moderate DCP enhanced crosslinking,improving storage modulus and thermal stability,while excessive DCP caused brittleness.Furthermore,MAH-g-PE effectively improved interfacial compatibility,and its synergy with DCP was dosage-dependent.Consequently,Sample 5 achieved optimal performance,exhibiting uniform fracture morphology,a shape fixation rate of98.8%with the fastest recovery,and balanced strength-ductility.Multi-criteria analysis identified elongation at break and recovery time as the top contributing factors,with consistent rankings validated by Spearman analysis(ρ=0.833,p<0.01).In summary,adjusting DCP and MAH-g-PE contents effectively modulates the crosslinking structure and interfacial properties of PLA/TPU composites,providing a viable strategy for developing high-performance,tunable 4D printing materials.展开更多
Huntington's disease(HD)is caused by the abnormal expansion of polyglutamine(poly Q)repeats encoded in exon 1 of the huntingtin(HTT)gene,with neurotoxicity typically emerging when the repeat length exceeds 36 glut...Huntington's disease(HD)is caused by the abnormal expansion of polyglutamine(poly Q)repeats encoded in exon 1 of the huntingtin(HTT)gene,with neurotoxicity typically emerging when the repeat length exceeds 36 glutamine residues.Increasing the poly Q length promotes hypercompact conformations;however,how such compact chains mechanically unfold under nanoconfinement remains insufficiently understood.In this study,all-atom molecular dynamics simulations were performed to investigate the nanopore transport and surface-induced unfolding of poly Q chains of different lengths(Q22,Q36,Q40,and Q46)through graphene nanopores under controlled pulling velocities.By quantitatively analyzing the transport dynamics,as characterized by the pulling force,radius of gyration,center-of-mass distance,interaction energies,number of transported residues,and pulling energy,we demonstrated that poly Q chains of all investigated lengths can successfully translocate through the nanopore and undergo progressive unfolding on the graphene surface over a wide range of pulling velocities.Longer poly Q chains exhibit a higher resistance to unfolding,characterized by enhanced force peaks and increased pulling energy,reflecting stronger intramolecular interactions.Moreover,slower pulling velocities reduce the force fluctuations and lower the overall pulling energy.These results provide molecular-level mechanistic insights into the length-dependent transport and surface-mediated unfolding of poly Q,offering a physical basis for understanding poly Q conformational regulation relevant to Huntington's disease.展开更多
Although poly(urethane-urea)elastomers(PUEs)possess excellent mechanical properties and durability,their inherent flammability and inability to self-repair after damage significantly limits their applications in high-...Although poly(urethane-urea)elastomers(PUEs)possess excellent mechanical properties and durability,their inherent flammability and inability to self-repair after damage significantly limits their applications in high-end fields.To address this challenge,this study employs a supramolecular chemistry approach by simultaneously incorporating multiple hydrogen bonds as dynamic cross-linking points and a phosphorus-nitrogen synergistic flame-retardant structure into the poly(urethane-urea)network.The multiple hydrogen bonds endow the material with efficient intrinsic self-healing capability,while the phosphorus-nitrogen flame retardant ensures outstanding thermal stability and flame resistance,leading to the successful synthesis of a high-performance multifunctional poly(urethane-urea)elastomer.Experimental results demonstrated that when the content of the flame retardant diethyl(2-((2-aminoethyl)amino)ethyl)phosphoramidate(DEPTA)was 10 wt%,the resulting PUE/10%DEPTA achieved a V-0 rating in the vertical burning test,with a limiting oxygen index(LOI)of 30%.Concurrently,the elastomer maintained good toughness,exhibiting a tensile strength of 27.3 MPa,an elongation at break of 601%,and a self-healing efficiency of up to 94.46%.This breakthrough shows significant promise for advanced engineering applications that demand fire safety,structural durability,and extended service life through self-repair.展开更多
The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly add...The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly additives,can scavenge free radicals to enhance polymer durability.However,rough choices have resulted in wastage of resources and environmental pressure.Based on the application of plastic films as the background for use,this study systematically evaluates application effects of five HALSs.The films underwent accelerated aging for various durations and were further investigated by a combination of experiments and molecular simulation.Results showed that all HALSs mitigated PBAT light aging,with Chimassorb-944(UV-944)and Tinuvin-770(UV-770)performing the best for real applications.Quantum chemical calculation results showed that UV-944 had stronger anti migration ability.After 300 h of aging,films with UV-944 and UV-770 retained superior tensile strength and elongation at break in the transverse direction compared to neat PBAT films.Polymeric HALSs provided better long-term stability than small-molecule ones.Further spectra analysis indicated that stronger C―O bonds in HALS/PBAT composites correlated with improved photostability.This study offers valuable insights into improving weather resistance of PBAT biodegradable films and optimizing the real application of HALSs.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 52203012)Shanghai Rising-Star Program (No. 23QC1400900).
文摘Ocean-degradable polyesters incorporating hydrophilic and rapidly degradable glycolide(GL)units into the polymer chain are the most promising for addressing marine plastic pollution,however,it is challenging to obtain high-molecular-weight copolymers with narrow molecular weight distributions.Herein,we prepared a novel biodegradable material,poly(butylene succinate-co-glycolide)(PBSGL),through ring-opening copolymerization using glycolide,succinic anhydride,and 1,4-butanediol as raw materials,providing a new solution strategy for marine pollution.GL could be polymerized according to the pre-designed composition by 1H-nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)results,indicating controlled polymerization with the synthesized PBSGLs having a weight-average molecular weight of up to 12.30×10^(4) g/mol and a narrow molecular weight distribution(1.33–1.65).Differential scanning calorimeter(DSC)and thermogravimetric analysis(TGA)results showed that T_(g) of PBSGLs increased from−32.5°C to−26.5°C with the increase of GL content from 0%to 40%,while T_(m)(>76°C)was much lower than T_(d,5%)(>314°C),which indicated that PBSGLs had good thermal stability and expanded the processing window and application range of the original poly(butylene succinate)(PBS)materials.Under simulated difficult conditions,PBSGL copolyesters could degrade faster with increasing GL content,where PBSGL40 degraded by 22.6%in 12 days,showing good biodegradability.Currently,most biodegradable polyesters with good performance slowly degrade in seawater.In a 30-day artificial seawater degradation test,the amorphous PBSGL40 copolyester showed a about 15-fold(2.33%weight loss)improvement in degradation ability compared to pure PBS,demonstrating rapid seawater degradation capability.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3700300)the National Natural Science Foundation of China(Nos.52573017 and U21B2093)+1 种基金Key Research and Development Program of Ningbo(No.2022Z200)the Zhejiang Provincial Natural Science Foundation(No.LY23E030005)。
文摘Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardant strategies often compromise their mechanical properties,hindering their practical applications.Herein,a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)-based comonomer(DDP)was used to synthesize flame-retardant poly(ethylene furandicarboxylate-co-phosphaphenanthrene)(PEFDn).The covalent integration of DDP confers intrinsic flame retardancy,avoiding the plasticization and migration issues associated with additive-type systems.Upon thermal decomposition,the DOPO-derived moieties release phosphoric acid and radical scavengers,promoting char formation and suppressing flame propagation.Furthermore,density functional theory(DFT)calculations combined with non-covalent interaction(NCI)analysis revealed that DOPO dimer molecules adopt a stable parallel-displaced π-π stacking configu ration,potentially facilitating microphase separation and enhancing the energy dissipation capability.PEFD_(10)achieves a UL-94 V-0 rating while simultaneously increasing impact toughness from 1.5 kJ/m^(2) to 14.7 kJ/m^(2).Im portantly,PEFDn maintained acceptable oxygen-barrier properties.PEFD10 also exhibited high transparency and UV-shielding performance.The combination of intrinsic flame safety,im pact-toughness resistance,UV shielding,and an oxygen barrier ensures reliable protection of electrical components and long-term operational stability.The integration of multiple critical properties within a single bio-based material represents a novel approach fo r enabling sustainable polymer solutions for high-pe rformance electrical applications.
基金supported by the Fundamental Research Funds for Central Universities(No.30922010811).
文摘It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.
基金supported by the National Key R&D Program of China(No.2023YFA1506804)the National Natural Science Foundation of China(Nos.22471110,22171111,22131007 and 22071093)+1 种基金the Science Foundation of Gansu Province of China(No.22JR5RA406)the Fundamental Research Funds for the Central Universities(No.lzujbky-2023-15)。
文摘Most commercial plastics cannot easily degrade,which raises a number of sustainability issues.To address the current problem of plastic pollution,the research and development of easily degradable and recyclable polymers has become an attractive subject.Herein,a new monomer of thiosalicylic methyl glycolide(TSMG)was synthesized using one-pot method and high molecular weight poly(thiosalicylic methyl glycolide)(PTSMG,M_(n) up to 300 kDa)can be obtained via the ring-opening polymerization(ROP)of TSMG.PTSMG exhibits good closed-loop recyclability and hydrolytic degradability,where PTSMG can generate pristine monomers through sublimation thermal depolymerization conditions due to the presence of thiophenol ester bond in the polymer chains,and can be degraded rapidly in aqueous solution,which provides a potential solution to the current plastic pollution problem.
基金financially supported by the Natural Science Foundation of Jilin Province Science and Technology Department(No.20230101221JC)the National Natural Science Foundation of China(Nos.52173115,52073278,52203189)the Research Foundation for Advanced Talents of Xiamen University of Technology(Nos.5010423019,YKJ22052R)。
文摘It is well known that cationic polymers have excellent antimicrobial capacity accompanied with high biotoxicity,to reduce biotoxicity needs to decrease the number of cationic groups on polymers,which will influence antimicrobial activity.It is necessary to design a cationic polymer mimic natural antimicrobial peptide with excellent antibacterial activity and low toxicity to solve the above dilemma.Here,we designed and prepared a series of cationic poly(β-amino ester)s(PBAEs)with different cationic contents,and introducing hydrophobic alkyl chain to adjust the balance between antimicrobial activity and biotoxicity to obtain an ideal antimicrobial polymer.The optimum one of synthesized PBAE(hydrophilic cationic monomer:hydrophobic monomer=5:5)was screened by testing cytotoxicity and minimum inhibitory concentration(MIC),which can effectively kill S.aureus and E.coli with PBAE concentration of15μg/m L by a spread plate bacteriostatic method and dead and alive staining test.The way of PBAE killing bacterial was destroying the membrane like natural antimicrobial peptide observed by scanning electron microscopy(SEM).In addition,PBAE did not exhibit hemolysis and cytotoxicity.In particular,from the result of animal tests,the PBAE was able to promote healing of infected wounds from removing mature S.aureus and E.coli on the surface of infected wound.As a result,our work offers a viable approach for designing antimicrobial materials,highlighting the significant potential of PBAE polymers in the field of biomedical materials.
基金supported by the Joint Funds of the National Natural Science Foundation of China(No.U21A20320)the National Natural Science Foundation of China(No.22106102)was also sponsored by the special fund of State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants(No.SEPKLEHIAEC-202203).
文摘Poly(butylene succinate-co-furandicarboxylate)(PBSF)and poly(butylene adipateco-furandicarboxylate)(PBAF)are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene succinate-co-terephthalate)(PBST)and poly(butylene adipate-co-terephthalate)(PBAT).In this study,quantum chemistry techniques after molecular dynamics simulations are employed to investigate the degradationmechanism of PBSF and PBAF catalyzed by Candida antarctica lipase B(CALB).Computational analysis indicates that the catalytic reaction follows a four-step mechanism resembling the ping-pong bibi mechanism,with the initial two steps being acylation reactions and the subsequent two being hydrolysis reactions.Notably,the first step of the hydrolysis is identified as the rate-determining step.Moreover,by introducing single-point mutations to expand the substrate entrance tunnel,the catalytic distance of the first acylation step decreases.Additionally,energy barrier of the rate-determining step is decreased in the PBSF system by site-directed mutations on key residues increasing hydrophobicity of the enzyme’s active site.This study unprecedently show the substrate binding pocket and hydrophobicity of the enzyme’s active site have the potential to be engineered to enhance the degradation of copolyesters catalyzed by CALB.
文摘Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport while maintaining the structural stability of the electrode under continuous charge‑discharge cycles.Electrochemical characterization under a three‑electrode system revealed exceptional rate capability:Mn@PN delivered an ultrahigh specific capacitance of 10318 F·g^(-1) at a low current density of 3 A·g^(-1) and retained 9415 F·g^(-1)(91.2%retention compared to the value at 3 A·g^(-1))even at an ultrahigh current density of 50 A·g^(-1).Moreover,the material exhibited 97.4%capacitance retention after 9000 cycles at 30 A·g^(-1),corresponding with a low capacitance decay rate of 0.003‰per cycle,significantly outperforming conventional conductive polymers like polyaniline(PANI).An asymmetric supercapacitor assembled with Mn@PN as the positive electrode(Mn@PN||AC)achieved an energy density of 328 Wh·kg^(-1) at 15 A·g^(-1) and retained 80.7%of its initial specific capacitance after 4000 cycles at 20 A·g^(-1).
基金financially supported by the Science and Technology Projects of Changji Prefecture(No.2023112258)Shihezi Coal Chemical Industry Common Technology Research Institute Project(No.MGJY0104)the Program for Young Innovative Talents of Shihezi University(No.CXFZ202302).
文摘In this study,a series of poly(ethylene succinate)-b-poly(butylene carbonate)(PES-b-PBC)multiblock copolymers were prepared through the chain-extension reaction of hydroxyl-terminated PES(PES-OH)and hydroxyl-terminated PBC(PBC-OH)prepolymers with 1,6-hexmethylene diisocyanate(HDI)as a chain extender.The effects of the prepolymer molecular weight and content on the structure and application properties of the PES-b-PBC copolymers were systematically investigated using various techniques.It was found that the compatibility of PES and PBC blocks in PES-b-PBC copolymers can be greatly enhanced by lowering the length of the prepolymers,and the amorphous phase of the PES and PBC chain segments in the PES-b-PBC copolymer would transform from immiscibility and partial miscibility to miscibility when the number-average molecular weight(M_(n))of the PES-OH and PBC-OH prepolymers is less than 2000 g/mol.Only the crystal structure of bare PES can be observed in the wide-angle X-ray diffraction(WAXD)spectrum of the PES-b-PBC copolymers,but their crystallinity degrees were found to decrease with increasing PBC fraction.The thermal behavior,crystallization performance,rheological properties,mechanical properties,and degradation properties of the PES-b-PBC multiblock copolymers can be easily modulated by altering the block length and composition of the prepolymers,offering potential applications in biodegradable materials.
基金financially supported by the National Natural Science Foundation of China(Nos.22173116 and 22473113)the Science Foundation of China University of Petroleum,Beijing(No.2462025YJRC032)for providing financial support.
文摘Poly(ethylene succinate)(PES),a promising biodegradable polyester with cost advantages,suffers from inherently slow crystallization kinetics,which severely limits its processability and practical applications.To address this challenge,this study explored the use of commercially available,low-cost,and food-safe sugar alcohols,including Xylitol(Xy),D-sorbitol(DS),and D-mannitol(DM),as effective nucleating agents for PES.Remarkably,all three polyols significantly enhanced the nucleation and crystallization ability of PES,with DM exhibiting the most pronounced effect.DM increased the crystallization temperature by up to 23.9°C and accelerated the overall crystallization rate by more than 13-fold at only 0.5 wt%loading level.Through a combination of differential scanning calorimetry(DSC),polarized optical microscopy(POM),and wide-angle X-ray diffraction(WAXD)analyses,we revealed that DM promotes PES crystallization via a dual mechanism:epitaxial templating facilitated by excellent lattice matching,and enhanced chain adjustment through intermolecular hydrogen-bonding interactions.In contrast,Xy and DS primarily function through hydrogen-bonding interactions.This work not only identifies DM as a highly efficient,economical,and industrially viable nucleating agent for PES,but also provides fundamental insights into the role of the molecular structure and crystallization ability of nucleating agents in regulating polymer crystallization.
基金supported by the Project of the National Science Foundation of China(Nos.52173033,51773044 and 51603047)Foshan Science and Technology Innovation Project(No.FS0AA-KJ919-4402-0145)。
文摘Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differences in their crystallization-promoting efficiency,and the underlying mechanism remains unclear.In this study,a series of nucleating agents,including N,N-diphenylterephthalamide(DPTA),N,N,N-triphenyl-1,3,5-benzenetricarboxamide(TPTA),N,N-diphenyl terephthalohydrazide(DBTA),and N,N,N-tribenzoyl-1,3,5-benzenetricarbohydrazide(TBTA),were designed and synthesized to investigate the differences in their effects on the crystallization performance of PLA.Density functional theory(DFT)and molecular dynamics(MD)simulations showed that DBTA had a smaller electrostatic potential difference(66.2 kcal/mol).During the cooling process,DBTA could stably form more intermolecular hydrogen bonds with PLA and exhibit a higher interaction energy,thus theoretically enabling more efficient promotion of PLA crystallization.Further differential scanning calorimetry(DSC)results revealed that at a 0.5wt%loading of DBTA,the crystallization peak temperature of the PLA-DBTA composite reached 118.1℃during cooling,whereas no distinct crystallization peak was observed for pure PLA under identical conditions.The crystallinity of the composite was significantly increased to 58.4%compared to 14.6%of pure PLA.Moreover,under isothermal crystallization at 130℃,DBTA reduced the half-crystallization time of PLA to 2.9min,while the half-crystallization time for pure PLA was 27.4 min.Time-resolved Fourier transform infrared spectroscopy(FTIR)results also confirmed that DBTA promoted the formation of gt conformational isomers of PLA during the crystallization process.This study elucidates the mechanism behind the performance differences between structurally similar nucleating agents in regulating PLA crystallization from the perspective of molecular electrostatic potential and hydrogen bonding interactions,providing a theoretical basis for the molecular design of efficient nucleating agents.
基金the financial support from the National Natural Science Foundation of China (No. 52072390)the National High-Level Talents Special Support Program (Leading Talent of Technological Innovation)+2 种基金the China Postdoctoral Science Foundation (No. 2023M743648)the Young Scientists Fund of the National Natural Science Foundation of China (No. 52302330)the support from the Shanghai Emperor of Cleaning Hi-Tech Co.,LTD
文摘In-situ poly(1,3-dioxolane)(PDOL)-based electrolyte has received extensive attention in the research of lithium metal batteries due to its high stability to lithium anode and simple processing.However,it is still faced with defects such as low intrinsic ionic conductivity,a narrow electrochemical window,and poor thermal stability.A crosslinking and fluorination molecular design strategy toward PDOL is proposed to tackle the issues above.The amorphous crosslinked structure effectively improves ionic conductivity by inhibiting long-chain crystallization.Especially,the antioxidant–CF_(3)groups,stable crosslinked structure,and reduced terminal hydroxyl groups significantly enhance the electrochemical oxidation stability with a superb high-voltage window of 4.7 V.In addition,the designed electrolyte also exhibits obviously improved thermal stability with no deformation at 120°C for 5 min.Furthermore,the semi-solid NCM811||Li batteries exhibit a favourable capacity retention of 88.8%after 150 cycles at 0.5 C.Even assembled with NCM622 cathode working at 4.5 V,the semi-solid batteries can still show a satisfactory capacity retention of 85.3%after 100 cycles at 0.5 C.Also,a 0.1 Ah NCM811||Li pouch cell with active materials loading of 9 mg/cm2 demonstrates satisfactory cycling stability and working ability,which shows promising practical application prospects.
基金financially supported by the Jiangsu Forestry Science and Technology Innovation and Promotion Project(No.LYKJ-Nanjing[2022]02)the Jiangsu Agricultural Science and Technology Innovation Fund(No.CX(23)3090)。
文摘Smart pesticide delivery systems based on stimuli-responsive nanocarriers have attracted considerable attention because of their potential to enhance pesticide efficiency while reducing environmental risks.In this study,a novel p H/glutathione dual-responsive pesticide delivery system was constructed through the synthesis of disulfide-bridged hollow mesoporous organosilica nanospheres(HMONs)via the St??ber method,followed by poly(acrylic acid)(PAA)coating through distillation-precipitation polymerization to form HMONs@PAA nanocomposites.The resulting abamectin-loaded system(Abamectin-HMONs@PAA)demonstrated a 12.73% pesticide loading capacity and significantly improved photostability,retaining twice as much active ingredient as free abamectin after 250 h of UV irradiation(36 W).Release studies revealed p H-and glutathione-dependent characteristics,with cumulative releases in acidic conditions exceeding those in neutral and alkaline environments by 18.66% and 40.98%,respectively,and a 14.2% increase in glutathione-containing solution(0.2 mmol·L^(-1) in 70% ethanol)after 97 h.Bioassays showed superior performance against Plutella xylostella,with a 13.33% reduction in survival rate compared to conventional suspension at equivalent dosage(40 mg·L^(-1)),while maintaining efficacy after extensive rainfall simulation(20 events over 10 days).This study provides a promising approach for developing environmentally responsive nanopesticides with enhanced durability and controlled-release properties,offering significant potential for sustainable crop protection.
基金the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C01072)the Institute of Zhejiang University-Quzhou for their financial support。
文摘Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.
基金financially supported by the National Key Research and Development Program of China(Nos.2022YFC2603500,2022YFC2603502)the Guangzhou Science and Technology Project(No.2024A04J4280).All authors acknowledge the financial support.
文摘Silica aerogels(SAs)impart low density and excellent thermal insulation to polymer systems,yet incorporating hydrophobic SAs into aqueous rubber latex systems remains challenging owing to their poor dispersibility and potential to destabilize the latex.Although previous studies have dispersed SAs in aqueous poly(vinyl alcohol)(PVA),the stability of such dispersions and their effectiveness as bridging media for latex integration have not been thoroughly evaluated,which limits their practical application in latex compounding.This study systematically examined how the surface chemistry governs hydrolytic stability,interfacial behavior,and latex compatibility in PVA-assisted aqueous processing.Two hydrophobic SAs were prepared:ethoxy-modified SA(E-SA)and methyl-modified SA(M-SA).Both initially formed a homogeneous PVA slurry,but E-SA rapidly hydrolyzed its surface—OCH_(2)CH_(3)groups,releasing ethanol,becoming hydrophilic,and undergoing irreversible nanopore collapse.In contrast,M-SA maintains its structural integrity and hydrophobicity because its—Si(CH_(3))_(3)groups are highly resistant to hydrolysis.This divergence dictates the behavior during latex blending.The ethanol released from E-SA disrupts electrostatic and steric stabilization,inducing latex coagulation,whereas M-SA/PVA dispersions preserve colloidal stability across diverse latex systems.As a practical demonstration,M-SA-reinforced chlorosulfonated polyethylene(CSM)rubber latex composites show more than a 50%reduction in thermal conductivity while maintaining chemical resistance,enabling high-performance insulating protective gloves and coatings.This work establishes a critical link between aerogel surface chemistry and aqueous processing stability,providing a mechanistic foundation for the rational design of water-based rubber/silica aerogel composites and next-generation thermal insulation materials.
基金supported in part by the National Institute of Environmental Health Sciences(Z01ES102745 to GH).
文摘Eukaryotic mRNAs are polyadenylated at their 3’-ends,and the poly(A)tails play critical roles in post-transcriptional gene regulation by influencing mRNA stability and translation.Here,we describe the biological processes and major protein factors that control poly(A)tail synthesis and shortening.We also discuss recent breakthroughs in poly(A)tail sequencing methods that enable high throughput and accurate measurement of poly(A)tail lengths.Finally,we review how poly(A)-tail regulators and poly(A)-tail-mediated post-transcriptional mechanisms affect stem cell fate and early embryonic development.
基金supported by the National Natural Science Foundation of China(No.22376091)the Natural Science Foundation of Hunan Province(No.2023JJ40530)the Scientific Research Fund of Hunan Provincial Education Department(No.23B0778).
文摘Efficient recovery of uranium from radioactive wastewater significantly has far-reaching positive implications for both the recycling of uranium resources and environmental conservation.In this work,a new stable hydrogel/MOFs composite with potential for efficient uranium capture has been developed.A double network structure was formed through the chemical covalent crosslinking of poly(acrylamide-acrylic acid) and the physical crosslinking of agar.The rapid self-crosslinking of agar not only enables the uniform dispersion of Metal-Organic Frameworks(MOFs) nanoparticles but also promotes the hydrogel to possess exceptional tensile strength and low swelling ratio,whereas the incorporation of amidoximated MOFs enhances the selectivity for uranium.The composite achieved a uranium-uptake capacity of 275.42 mg/g(298 K,C0=120 mg/L,pH=6),and it retains reproducible and stable after five cycles,while exhibiting high selectivity for uranyl,even amidst ten competing metal ions.Moreover,the uranium removal rate reached 93 % within three days in low concentration simulated nuclear wastewater.Multiple spectral analyses coupled with theoretical calculations confirmed that the mechanism of U(Ⅵ) capture involves intraparticle diffusion,along with the coordination of amidoxime,carboxyl,and amino groups.This research offers a valuable reference for the development of composite materials to treat radioactive effluent.
基金supported by the National Natural Science Foundation of China(No.51905543)。
文摘This study aimed to systematically regulate the performance of 4D printing composites by investigating the synergistic effects of dicumyl peroxide(DCP)and maleic anhydride-grafted polyethylene(MAH-g-PE)on a poly(lactic acid)/thermoplastic polyurethane(PLA/TPU)matrix.Specifically,using a 70 wt%/30 wt%PLA/TPU matrix and an L_(9)(3^(2))orthogonal design,composites were evaluated via morphology,shape memory,mechanical tests,and multi-criteria analysis.Moderate DCP enhanced crosslinking,improving storage modulus and thermal stability,while excessive DCP caused brittleness.Furthermore,MAH-g-PE effectively improved interfacial compatibility,and its synergy with DCP was dosage-dependent.Consequently,Sample 5 achieved optimal performance,exhibiting uniform fracture morphology,a shape fixation rate of98.8%with the fastest recovery,and balanced strength-ductility.Multi-criteria analysis identified elongation at break and recovery time as the top contributing factors,with consistent rankings validated by Spearman analysis(ρ=0.833,p<0.01).In summary,adjusting DCP and MAH-g-PE contents effectively modulates the crosslinking structure and interfacial properties of PLA/TPU composites,providing a viable strategy for developing high-performance,tunable 4D printing materials.
基金supported by the National Natural Science Foundation of China(Nos.12302408,20904047 and62375245)the Natural Science Foundation of Zhejiang Province(Nos.LY17A040001 and LY19F03004)+1 种基金the ZUST Postgraduate Course Development Fund(No.2025yjskj05)the ZUST Postgraduate Research and Innovation Fund(No.2025yjskc20)。
文摘Huntington's disease(HD)is caused by the abnormal expansion of polyglutamine(poly Q)repeats encoded in exon 1 of the huntingtin(HTT)gene,with neurotoxicity typically emerging when the repeat length exceeds 36 glutamine residues.Increasing the poly Q length promotes hypercompact conformations;however,how such compact chains mechanically unfold under nanoconfinement remains insufficiently understood.In this study,all-atom molecular dynamics simulations were performed to investigate the nanopore transport and surface-induced unfolding of poly Q chains of different lengths(Q22,Q36,Q40,and Q46)through graphene nanopores under controlled pulling velocities.By quantitatively analyzing the transport dynamics,as characterized by the pulling force,radius of gyration,center-of-mass distance,interaction energies,number of transported residues,and pulling energy,we demonstrated that poly Q chains of all investigated lengths can successfully translocate through the nanopore and undergo progressive unfolding on the graphene surface over a wide range of pulling velocities.Longer poly Q chains exhibit a higher resistance to unfolding,characterized by enhanced force peaks and increased pulling energy,reflecting stronger intramolecular interactions.Moreover,slower pulling velocities reduce the force fluctuations and lower the overall pulling energy.These results provide molecular-level mechanistic insights into the length-dependent transport and surface-mediated unfolding of poly Q,offering a physical basis for understanding poly Q conformational regulation relevant to Huntington's disease.
文摘Although poly(urethane-urea)elastomers(PUEs)possess excellent mechanical properties and durability,their inherent flammability and inability to self-repair after damage significantly limits their applications in high-end fields.To address this challenge,this study employs a supramolecular chemistry approach by simultaneously incorporating multiple hydrogen bonds as dynamic cross-linking points and a phosphorus-nitrogen synergistic flame-retardant structure into the poly(urethane-urea)network.The multiple hydrogen bonds endow the material with efficient intrinsic self-healing capability,while the phosphorus-nitrogen flame retardant ensures outstanding thermal stability and flame resistance,leading to the successful synthesis of a high-performance multifunctional poly(urethane-urea)elastomer.Experimental results demonstrated that when the content of the flame retardant diethyl(2-((2-aminoethyl)amino)ethyl)phosphoramidate(DEPTA)was 10 wt%,the resulting PUE/10%DEPTA achieved a V-0 rating in the vertical burning test,with a limiting oxygen index(LOI)of 30%.Concurrently,the elastomer maintained good toughness,exhibiting a tensile strength of 27.3 MPa,an elongation at break of 601%,and a self-healing efficiency of up to 94.46%.This breakthrough shows significant promise for advanced engineering applications that demand fire safety,structural durability,and extended service life through self-repair.
基金supported by the Key Research and Development Task Project of Xinjiang Uygur Autonomous Region(No.2022B02033)the National Natural Science Foundation of China(Nos.42211530566 and 42311530066)+2 种基金the NSFC-FNRS Joint Program BIOAGRIFILM(No.FNRS PINT-BILATM 2022)the Science and Technology Project of Bijie Tobacco Company of Guizhou Province(No.2022520500240192)the Agricultural Science and Technology Innovation Program(ASTIP)。
文摘The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly additives,can scavenge free radicals to enhance polymer durability.However,rough choices have resulted in wastage of resources and environmental pressure.Based on the application of plastic films as the background for use,this study systematically evaluates application effects of five HALSs.The films underwent accelerated aging for various durations and were further investigated by a combination of experiments and molecular simulation.Results showed that all HALSs mitigated PBAT light aging,with Chimassorb-944(UV-944)and Tinuvin-770(UV-770)performing the best for real applications.Quantum chemical calculation results showed that UV-944 had stronger anti migration ability.After 300 h of aging,films with UV-944 and UV-770 retained superior tensile strength and elongation at break in the transverse direction compared to neat PBAT films.Polymeric HALSs provided better long-term stability than small-molecule ones.Further spectra analysis indicated that stronger C―O bonds in HALS/PBAT composites correlated with improved photostability.This study offers valuable insights into improving weather resistance of PBAT biodegradable films and optimizing the real application of HALSs.
