Nowadays,the development of effective bioplastics aims to combine traditional plastics’functionality with environmentally friendly properties.The most effective and durable modern bioplastics are made from the edible...Nowadays,the development of effective bioplastics aims to combine traditional plastics’functionality with environmentally friendly properties.The most effective and durable modern bioplastics are made from the edible part of crops.This forces bioplastics to competewith food production because the crops that produce bioplastics can also be used for human nutrition.That is why the article’s main focus is on creating bioplastics using renewable,non-food raw materials(cellulose,lignin,etc.).Eco-friendly composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)with reed and hemp waste as a filler.The physic-chemical features of the structure and surface,as well as the technological characteristics of reed and hemp waste as the organic fillers for renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid),were studied.Theeffect of the fractional composition analysis,morphology,and nature of reed and hempwaste on the quality of the design of eco-friendly biodegradable composites and their ability to disperse in the matrix of renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch and poly(lactic acid)was carried out.The influence of different content and morphology of reed and hemp waste on the composite characteristics was investigated.It is shown that the most optimal direction for obtaining strong eco-friendly biodegradable composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)is associated with the use of waste reed stalks,with its optimal content at the level of 50 wt.%.展开更多
The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler ne...The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler network evolution.Under dynamic conditions,small oscillatory shear strains (0.1%) significantly enhanced filler particle motion,leading to pronounced agglomeration and a flocculation degree of about 4.3MPa at 145℃.In contrast,static flocculation exhibited a fundamentally different mechanism dominated by polymer chain dynamics,which is driven mainly by thermal activation.Radial distribution function (RDF) analysis of transmission electron microscopy (TEM) images revealed a slight decrease (2 nm) in the interparticle distance peak after static annealing at 100℃ for 7 h,indicating localized motion of CB particles.However,the overall filler network remained stable,with no significant agglomeration observed.The increase in bound rubber content from about 23% to 28% with rising temperature further confirmed the dominant role of polymer chain adsorption and interfacial reinforcement in static flocculation.These findings highlight the critical influence of external strain on filler network formation and provide new insights into the polymer-dominated mechanism of static flocculation.The results offer practical guidance for optimizing the storage and processing of rubber nanocomposites,particularly in applications where static flocculation during prolonged storage is a concern.展开更多
As living standards improve,the energy consumption for regulating indoor temperature keeps increasing.Windows,in particular,enhance indoor brightness but also lead to increased energy loss,especially in sunny weather....As living standards improve,the energy consumption for regulating indoor temperature keeps increasing.Windows,in particular,enhance indoor brightness but also lead to increased energy loss,especially in sunny weather.Developing a product that can maintain indoor brightness while reducing energy consumption is a challenge.We developed a facile,spectrally selective transparent ultrahigh-molecular-weight polyethylene composite film to address this trade-off.It is based on a blend of antimony-doped tin oxide and then spin-coated hydrophobic fumed silica,achieving a high visible light transmittance(>70%)and high shielding rates for ultraviolet(>90%)and near-infrared(>70%).When applied to the acrylic window of containers and placed outside,this film can cause a 10℃ temperature drop compared to a pure polymer film.Moreover,in building energy simulations,the annual energy savings could be between 14.1%~31.9%per year.The development of energy-efficient and eco-friendly transparent films is crucial for reducing energy consumption and promoting sustainability in the window environment.展开更多
The early stages of crystallization and occurrence of surface wrinkling were investigated using poly(butadiene)-block-poly(ε-caprolactone)with an ordered lamellar structure.Direct evidence has demonstrated that surfa...The early stages of crystallization and occurrence of surface wrinkling were investigated using poly(butadiene)-block-poly(ε-caprolactone)with an ordered lamellar structure.Direct evidence has demonstrated that surface wrinkling precedes nucleation and crystal growth.This study examined the relationship between surface wrinkling,nucleation,and the formation of crystalline supramolecular structures using atomic force microscopy(AFM)and X-ray scattering measurements.Surface wrinkling is attributed to curving induced by accumulated stresses,including residual stress from the sample preparation and thermal stress during cooling.These stresses cause large-scale material flow and corresponding changes in the molecular conformations,potentially reducing the nucleation barrier.This hypothesis is supported by the rapid crystal growth observed following the spread of surface wrinkles.Additionally,the surface curving of the polymer thin film creates local minima of the free energy,facilitating nucleation.The nuclei subsequently grow into crystalline supramolecular structures by incorporating polymer molecules from the melt.This mechanism highlights the role of localized structural inhomogeneity in the early stages of crystallization and provides new insights into structure formation processes.展开更多
A comparative analysis was performed on poly(lactic acid)(PLA),poly(caprolactone)(PCL),basalt fiber(BF)composites produced using two distinct approaches:direct blending and masterbatching.The limitations of PLA-BF com...A comparative analysis was performed on poly(lactic acid)(PLA),poly(caprolactone)(PCL),basalt fiber(BF)composites produced using two distinct approaches:direct blending and masterbatching.The limitations of PLA-BF composites with regard to distribution and adhesion are well-documented,as are chemical treatment methods(addition of compatibilisers,surface treatments,silanization).This work aimed to study an industrially relevant potential solution of utilising a PCL-BF masterbatch,prepared as a 50/50 wt.%blend using planetary roller extrusion(PEX)to both improve the distribution and homogeneity of the fibers as well as provide a secondary adhesion site to facilitate improved mechanical properties of the final PLA-PCL-BF composite.The resultant materials were injection moulded to prepare ISO standard test specimens and tested on the basis of their physical properties via tensile testing,impact strength testing,flexural analysis,Fourier transforminfrared spectroscopy and water absorption capability.The results displayed that the incorporation of PCL and BF led to an increase in ductility of the composite materials,allowing for improvements in the inherent brittleness of virgin PLA.Major increases in the impact strength were achieved with the utilisation of a 25% PCL/BF masterbatch,allowing for a greater than 50%increase.As an overall observation,the use of a masterbatching process,opposed to direct blending of the constituent materials allows for a greater consistency of composite to be achieved at the expense of increased gains.展开更多
The development of epoxy(EP)nanocomposites has emerged as a prominent research area across diverse sectors,including automotive,construction,and aerospace industries.Recently,adopting biomimetic strategies for the pre...The development of epoxy(EP)nanocomposites has emerged as a prominent research area across diverse sectors,including automotive,construction,and aerospace industries.Recently,adopting biomimetic strategies for the preparation of nanomaterials to design multifunctional epoxy resins has emerged as a prominent research hotspot.Inspired by the growth pattern of coral reefs,this study successfully engineered a novel hierarchical nanostructured material(Fe-NiPS-PBA)with the aim of creating EP nanocomposites that exhibit highly flame-retardant efficiency,exceptional mechanical strength,and distinguished wear-resisting property even at low additive concentrations.With a 3 wt%addition of Fe-NiPS-PBA,the limiting oxygen index of the EP/3Fe-NiPS-PBA nanocomposite increased from 23.5 to 25.9,achieving a UL-94 V-0 rating.Compared to pure EP,EP/3Fe-NiPSPBA nanocomposite reduced the peak heat release rate(PHRR),total heat release(THR),peak smoke production rate(PSPR),total smoke production(TSP),and maximum CO emission(MCO)by 44.1%,66.7%,47.0%,67.8%,and 51.7%,respectively.Moreover,the incorporation of a 1 wt%additive resulted in significant enhancements of tensile strength from 76.7 MPa to 96.9 MPa,while the wear rate demonstrated a remarkable reduction of 77.8%.The Fe-NiPS-PBA significantly enhanced the fire performance and mechanical strength of EP nanocomposites,demonstrating exceptional overall performance in various applications.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
The demand for high-temperature electromagnetic wave absorption(EWA)materials has significantly increased alongside advancements in aerospace and communication technologies.Although traditional magnetic absorbers,such...The demand for high-temperature electromagnetic wave absorption(EWA)materials has significantly increased alongside advancements in aerospace and communication technologies.Although traditional magnetic absorbers,such as ferrites and metal powders,show excellent magnetic loss performance at room temperature,they have significant limitations in harsh environments due to their high density,low Curie temperature,and susceptibility to oxidation.In contrast,carbon-containing materials have emerged as promising candidates for high-temperature EWA applications,owing to their high melting point,low density,tunable dielectric loss mechanisms,and superior thermal stability.Unlike magnetic materials,carbon-based systems primarily dissipate electromagnetic energy through conductance loss,dipole polarization,and interfacial polarization,thereby avoiding performance degradation at elevated temperatures.However,several critical challenges remain,including insufficient oxidation resistance,mechanical reliability issues,and the need for stable impedance matching.To address these limitations,recent strategies such as defect engineering,heterointerface construction,and metamaterial design have been proposed to enhance thermal stability and functional performance.This review provides a systematic summary of recent advances in carbon-containing absorbers,with a focus on dielectric loss mechanisms,optimization strategies,and multiscale structural design principles.By elucidating the structure–property relationships of carbon materials,carbide ceramics,and novel carbon hybrids,this study aims to offer theoretical and technical guidance for the development of advanced high-temperature electromagnetic wave absorbers,thereby promoting their practical applications in aerospace and telecommunications.展开更多
The concept of self-healing that involves a built-in ability to heal in response to damage wherever and whenever it occurs in a material,analogous to the healing process in living organisms,has emerged a couple of dec...The concept of self-healing that involves a built-in ability to heal in response to damage wherever and whenever it occurs in a material,analogous to the healing process in living organisms,has emerged a couple of decades ago.Driven primarily by the demands for life-like materials and soft smart materials,therefore,the development of self-healing polymeric hydrogels has continually attracted the attention of the scientific community.Here,this review is intended to give an in-depth overview of the state-of-the-art advances in the field of self-healing polymeric hydrogels.Specifically,recently emerging trends in self-healing polymeric hydrogels are summarized,and notably,recommendations to endow these hydrogels with fascinating multi-functionalities including luminescence,conductivity/magnetism and shape memory etc are presented.To close,the current challenges and future opportunities in this field are also discussed.展开更多
By changing both the monomer composition and the polymer structure, we have varied the mechanical properties of resorbable polymers. The polymers were synthesized by ring-opening polymerization using L-lactide （LLA...By changing both the monomer composition and the polymer structure, we have varied the mechanical properties of resorbable polymers. The polymers were synthesized by ring-opening polymerization using L-lactide （LLA）, ε-caprolactone （εCL）, trimethylene carbonate （TMC） and 1,5-dioxepan-2-one （DXO） as monomers. Well-defined triblock copolymers, microblock copolymers and networks have been evaluated, and comparisons between them show that it is possible to tune the mechanical properties. Triblock copolymers with an amorphous middle block of poly（1,5-dioxepan-2- one） （PDXO） and semi-crystalline end-blocks of poly（ε-caprolactone） （PCL） were stronger and had a higher strain at break than triblock copolymers with poly（L-lactide） （PLLA） as end-blocks. Polymers with both DXO and TMC in the amorphous middle-block and PLLA as end-blocks showed a lower stress at break, but the material gained elasticity, a property which is very valuable in tissue engineering. Mechanical properties of networks, synthesized by a novel method, containing PDXO and PCL are also presented. Although it is difficult to compare them with the uncross-linked polymers, this is an additional way to modify and widen the properties.展开更多
A new process for lamination of polymer films by 'bulk surface photografting' has been developed. The chemical component of the invention is that the curing of reactive solution between two substrates is initi...A new process for lamination of polymer films by 'bulk surface photografting' has been developed. The chemical component of the invention is that the curing of reactive solution between two substrates is initiated by the surface free radicals produced by aromatic ketones and surface-hydrogen of substrates. Using the new approach, two or more polymer films are bonded together by a grafted polymer network which is grafted to adjacent substrate surfaces. The technique has been applied to film substrates of different polymers such as polyolefins, polyesters, and polyamides which have abstractable hydrogens at the surface. The photolaminated film composites containing carrier films and an intermediate functional film of low permeability give strong laminates with high barrier properties, e.g, for oxygen and air.展开更多
Nowadays, the use of natural fiber reinforced polymer-based composites is gradually increasing day by day for their many advantages for civil engineering construction applications. Due to their many advantages for pol...Nowadays, the use of natural fiber reinforced polymer-based composites is gradually increasing day by day for their many advantages for civil engineering construction applications. Due to their many advantages for polymer-based composite materials are widely used in civil construction, automobiles, aerospace, and many others. Natural fibers such as jute, kenaf, pineapple, sugarcane, hemp, oil palm, flax, and leaf, etc. are cheap, environmentally friendly, renewable, completely and partially biodegradable which can be utilized to obtain new high-performance polymer materials. These composites are having satisfactory mechanical properties (i.e. tensile properties, flexural stress-strain behavior, fracture toughness, and fracture strength) which make them more attractive than other composites. Due to easy availability and renewability, natural fibers can be used as an alternative of synthetic fibers as a reinforcing agent. The aim of this paper is to review different natural fibers reinforced based polymer composites with mechanical characterization, applications, also shows the opportunities, challenges and future demand of natural composite material towards civil applications.展开更多
The use of composites in different sectors has become inevitable due to the enhancement in properties, reduction in the manufacturing cost and suitability to several applications. Among different classifications, poly...The use of composites in different sectors has become inevitable due to the enhancement in properties, reduction in the manufacturing cost and suitability to several applications. Among different classifications, polymeric composites are mainly focused on their use as structural components and the selection and composition of reinforcement play a vital role in determining the characteristics of the composite. Although composites are developed with man-made reinforcement in the beginning stage, in the present situation, natural reinforcements have proved excellent results in terms of properties. Hence, nowadays researches are mainly focused on the use of different natural fibers in different forms as reinforcements in polymeric composite. This work presents a brief overview on the properties of natural fiber and natural fiber reinforced composites which is an emerging area in polymer science. Interests in natural fiber is reasonable due to the advantages of these materials compared to others, such as synthetic fiber composites, including low environmental impact and low cost and support their potential to be used. Moreover, the disadvantage of the synthetic and fiber-glass as reinforcement, the use of natural fiber reinforced composite gained the attention of the young scientists, researchers, and engineers and are being exploited as a replacement for the conventional fiber such as glass, aramid, carbon etc. Natural fibers have been proven alternative to synthetic fiber in transportation such as automobiles, railway coaches and aerospace, military, building, packaging, consumer products and construction industries for ceiling paneling, partition boards etc. However, in development of these composites, some drawbacks have also emerged. In this paper, it has been tried to overview all of this together.展开更多
A new crosslinked polymer,called P65,with appropriate photo-electrochemical,opto-electronic,and thermal properties,has been designed and synthesized as an efficient,dopant-free,hole-transport material(HTM)for n-i-p ty...A new crosslinked polymer,called P65,with appropriate photo-electrochemical,opto-electronic,and thermal properties,has been designed and synthesized as an efficient,dopant-free,hole-transport material(HTM)for n-i-p type planar perovskite solar cells(PSCs).P65 is obtained from a low-cost and easily synthesized spiro[fluorene-9,90-xanthene]-30,60-diol(SFX-OH)-based monomer X65 through a freeradical polymerization reaction.The combination of a three-dimensional(3 D)SFX core unit,holetransport methoxydiphenylamine group,and crosslinked polyvinyl network provides P65 with good solubility and excellent film-forming properties.By employing P65 as a dopant-free hole-transport layer in conventional n-i-p type PSCs,a power conversion efficiency(PCE)of up to 17.7%is achieved.To the best of our knowledge,this is the first time a 3 D,crosslinked,polymeric dopant-free HTM has been reported for use in conventional n-i-p type PSCs.This study provides a new strategy for the future development of a 3 D crosslinked polymeric dopant-free HTM with a simple synthetic route and low-cost for commercial,large-scale applications in future PSCs.展开更多
Thin films of perovskite deposited from solution inevitably introduce large number of defects,which serve as recombination centers and are detrimental for solar cell performance.Although many small molecules and polym...Thin films of perovskite deposited from solution inevitably introduce large number of defects,which serve as recombination centers and are detrimental for solar cell performance.Although many small molecules and polymers have been delicately designed to migrate defects of perovskite films,exploiting credible passivation agents based on natural materials would offer an alternative approach.Here,an ecofriendly and cost-effective biomaterial,ploy-L-lysine(PLL),is identified to effectively passivate the defects of perovskite films prepared by blade-coating.It is found that incorporation of a small amount(2.5 mg mL^(-1))of PLL significantly boosts the performance of printed devices,yielding a high efficiency of 19.45% with an increase in open-circuit voltage by up to 100 mV.Density functional theory calculations combined with X-ray photoelectron spectroscopy reveal that the functional groups(-NH2,-COOH)of PLL effectively migrate the Pb-I antisite defects via Pb-N coordination and suppress the formation of metallic Pb in the blade-coated perovskite film.This work suggests a viable avenue to exploit passivation agents from natural materials for preparation of high-quality perovskite layers for optoelectronic applications.展开更多
The target of the present investigation is synthesis and characterization of an amphiphilic diblock copolymer with antibacterial property. Ring opening polymerization （ROP） of ε-caprolactone （CL） and tetrahydrofu...The target of the present investigation is synthesis and characterization of an amphiphilic diblock copolymer with antibacterial property. Ring opening polymerization （ROP） of ε-caprolactone （CL） and tetrahydrofuran （THF） was carried out under inert atmosphere by using L-cysteine as a bridging agent in the presence of stannous octoate （SO） as a catalyst. The nano silver end capped diblock copolymer was synthesized by in situ method. Thus obtained nano silver end capped L-cysteine bridged diblock copolymer was characterized by various analytical methods like Fourier transform infrared （FTIR） spectroscopy, nuclear magnetic resonance （NMR） spectroscopy, circular dichroism （CD）, fluorescence spectroscopy, gel permeation chromatography （GPC）, X-ray photoelectron spectroscopy （XPS）, thermogravimetric analysis （TGA）, differential scanning calorimetry （DSC）, field emission scanning electron microscopy （FESEM）, high resolution transmission electron microscopy （HRTEM） and zeta potential. The antimicrobial property of the nano silver end capped diblock copolymer against e-coli was tested.展开更多
Poly(phenylene oxide)/renewable polyamide 11 (PPO/PA11 20/80) blends toughened with glycidylmethacrylate grafted ethylene-n-octene copolymer (GEOC) were prepared in a co-rotating twin-screwextruder. The reaction betwe...Poly(phenylene oxide)/renewable polyamide 11 (PPO/PA11 20/80) blends toughened with glycidylmethacrylate grafted ethylene-n-octene copolymer (GEOC) were prepared in a co-rotating twin-screwextruder. The reaction between GEOC and PPO/PA11 blend was analyzed by gel content tests. Themorphology of PPO/PA11/GEOC blends was observed by scanning electron microscope. The SEMresults showed that PPO formed the continuous phase, though it is a minority component of blends. Withincreasing GEOC content from 5 to 15 wt% the morphology of the blends transformed from droplet-matrix toco-continuous structure, in which both PA11 and PPO phases are continuous. The blend with co-continuousmorphology had better mechanical properties than those with droplet-matrix morphology. The impactstrength of the PPO/PA11/GEOC blends was much higher compared to the one without GEOC as well asPA11 due to the compatibilizing effect, which was also proved by DSC analysis, rheological behavior (MFR,DMTA) and tensile properties.展开更多
External magnetic field increases the photo-induced polymerization rate of styrene microemulsion.The type of photoinitiator plays an important role. The photoinitiators, used are dimethoxyphenyl acetophenone(DMPA), 1-...External magnetic field increases the photo-induced polymerization rate of styrene microemulsion.The type of photoinitiator plays an important role. The photoinitiators, used are dimethoxyphenyl acetophenone(DMPA), 1-hydroxycyclohexyl phenylketone (Irgacure 184) and dimethylhydroxyacetophenone (Darocur 1173). No magnetic effect was observed by using dibenzylketone (DBK) as photoinitiator. The molecular weight of the polymer is slightly affected by magnetic field. The influence of temperature has also been investigated.展开更多
文摘Nowadays,the development of effective bioplastics aims to combine traditional plastics’functionality with environmentally friendly properties.The most effective and durable modern bioplastics are made from the edible part of crops.This forces bioplastics to competewith food production because the crops that produce bioplastics can also be used for human nutrition.That is why the article’s main focus is on creating bioplastics using renewable,non-food raw materials(cellulose,lignin,etc.).Eco-friendly composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)with reed and hemp waste as a filler.The physic-chemical features of the structure and surface,as well as the technological characteristics of reed and hemp waste as the organic fillers for renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid),were studied.Theeffect of the fractional composition analysis,morphology,and nature of reed and hempwaste on the quality of the design of eco-friendly biodegradable composites and their ability to disperse in the matrix of renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch and poly(lactic acid)was carried out.The influence of different content and morphology of reed and hemp waste on the composite characteristics was investigated.It is shown that the most optimal direction for obtaining strong eco-friendly biodegradable composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)is associated with the use of waste reed stalks,with its optimal content at the level of 50 wt.%.
基金supported by the National Natural Science Foundation of China(No.52293471)National Key R&D Program of China(No.2022YFB3707303).
文摘The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler network evolution.Under dynamic conditions,small oscillatory shear strains (0.1%) significantly enhanced filler particle motion,leading to pronounced agglomeration and a flocculation degree of about 4.3MPa at 145℃.In contrast,static flocculation exhibited a fundamentally different mechanism dominated by polymer chain dynamics,which is driven mainly by thermal activation.Radial distribution function (RDF) analysis of transmission electron microscopy (TEM) images revealed a slight decrease (2 nm) in the interparticle distance peak after static annealing at 100℃ for 7 h,indicating localized motion of CB particles.However,the overall filler network remained stable,with no significant agglomeration observed.The increase in bound rubber content from about 23% to 28% with rising temperature further confirmed the dominant role of polymer chain adsorption and interfacial reinforcement in static flocculation.These findings highlight the critical influence of external strain on filler network formation and provide new insights into the polymer-dominated mechanism of static flocculation.The results offer practical guidance for optimizing the storage and processing of rubber nanocomposites,particularly in applications where static flocculation during prolonged storage is a concern.
基金financially supported by the Natural Science Foundation of Henan(242300421010)National Natural Science Foundation of China(52403055).
文摘As living standards improve,the energy consumption for regulating indoor temperature keeps increasing.Windows,in particular,enhance indoor brightness but also lead to increased energy loss,especially in sunny weather.Developing a product that can maintain indoor brightness while reducing energy consumption is a challenge.We developed a facile,spectrally selective transparent ultrahigh-molecular-weight polyethylene composite film to address this trade-off.It is based on a blend of antimony-doped tin oxide and then spin-coated hydrophobic fumed silica,achieving a high visible light transmittance(>70%)and high shielding rates for ultraviolet(>90%)and near-infrared(>70%).When applied to the acrylic window of containers and placed outside,this film can cause a 10℃ temperature drop compared to a pure polymer film.Moreover,in building energy simulations,the annual energy savings could be between 14.1%~31.9%per year.The development of energy-efficient and eco-friendly transparent films is crucial for reducing energy consumption and promoting sustainability in the window environment.
基金the National Natural Science Foundation of China(Nos.U2032101 and 11905306)the National Key Research and Development Project of China(No.2022YFB2402602).
文摘The early stages of crystallization and occurrence of surface wrinkling were investigated using poly(butadiene)-block-poly(ε-caprolactone)with an ordered lamellar structure.Direct evidence has demonstrated that surface wrinkling precedes nucleation and crystal growth.This study examined the relationship between surface wrinkling,nucleation,and the formation of crystalline supramolecular structures using atomic force microscopy(AFM)and X-ray scattering measurements.Surface wrinkling is attributed to curving induced by accumulated stresses,including residual stress from the sample preparation and thermal stress during cooling.These stresses cause large-scale material flow and corresponding changes in the molecular conformations,potentially reducing the nucleation barrier.This hypothesis is supported by the rapid crystal growth observed following the spread of surface wrinkles.Additionally,the surface curving of the polymer thin film creates local minima of the free energy,facilitating nucleation.The nuclei subsequently grow into crystalline supramolecular structures by incorporating polymer molecules from the melt.This mechanism highlights the role of localized structural inhomogeneity in the early stages of crystallization and provides new insights into structure formation processes.
文摘A comparative analysis was performed on poly(lactic acid)(PLA),poly(caprolactone)(PCL),basalt fiber(BF)composites produced using two distinct approaches:direct blending and masterbatching.The limitations of PLA-BF composites with regard to distribution and adhesion are well-documented,as are chemical treatment methods(addition of compatibilisers,surface treatments,silanization).This work aimed to study an industrially relevant potential solution of utilising a PCL-BF masterbatch,prepared as a 50/50 wt.%blend using planetary roller extrusion(PEX)to both improve the distribution and homogeneity of the fibers as well as provide a secondary adhesion site to facilitate improved mechanical properties of the final PLA-PCL-BF composite.The resultant materials were injection moulded to prepare ISO standard test specimens and tested on the basis of their physical properties via tensile testing,impact strength testing,flexural analysis,Fourier transforminfrared spectroscopy and water absorption capability.The results displayed that the incorporation of PCL and BF led to an increase in ductility of the composite materials,allowing for improvements in the inherent brittleness of virgin PLA.Major increases in the impact strength were achieved with the utilisation of a 25% PCL/BF masterbatch,allowing for a greater than 50%increase.As an overall observation,the use of a masterbatching process,opposed to direct blending of the constituent materials allows for a greater consistency of composite to be achieved at the expense of increased gains.
基金Outstanding Youth Scientific Research Project in Anhui Province(2022AH020055)Key Research and Development Projects in Anhui Province(2022i01020016)。
文摘The development of epoxy(EP)nanocomposites has emerged as a prominent research area across diverse sectors,including automotive,construction,and aerospace industries.Recently,adopting biomimetic strategies for the preparation of nanomaterials to design multifunctional epoxy resins has emerged as a prominent research hotspot.Inspired by the growth pattern of coral reefs,this study successfully engineered a novel hierarchical nanostructured material(Fe-NiPS-PBA)with the aim of creating EP nanocomposites that exhibit highly flame-retardant efficiency,exceptional mechanical strength,and distinguished wear-resisting property even at low additive concentrations.With a 3 wt%addition of Fe-NiPS-PBA,the limiting oxygen index of the EP/3Fe-NiPS-PBA nanocomposite increased from 23.5 to 25.9,achieving a UL-94 V-0 rating.Compared to pure EP,EP/3Fe-NiPSPBA nanocomposite reduced the peak heat release rate(PHRR),total heat release(THR),peak smoke production rate(PSPR),total smoke production(TSP),and maximum CO emission(MCO)by 44.1%,66.7%,47.0%,67.8%,and 51.7%,respectively.Moreover,the incorporation of a 1 wt%additive resulted in significant enhancements of tensile strength from 76.7 MPa to 96.9 MPa,while the wear rate demonstrated a remarkable reduction of 77.8%.The Fe-NiPS-PBA significantly enhanced the fire performance and mechanical strength of EP nanocomposites,demonstrating exceptional overall performance in various applications.
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 National Natural Science Foundation of China(52572086 and 52502371)the Natural Science Foundation of Henan(242300421010)+2 种基金Scientific and Technological Innovation Talents in Colleges and Universities in Henan Province(22HASTIT001)the Henan Province Natural Science Foundation Outstanding Youth Fund Project(242300421009)the Henan Province science and technology research project(252102320354and 252102230037)。
文摘The demand for high-temperature electromagnetic wave absorption(EWA)materials has significantly increased alongside advancements in aerospace and communication technologies.Although traditional magnetic absorbers,such as ferrites and metal powders,show excellent magnetic loss performance at room temperature,they have significant limitations in harsh environments due to their high density,low Curie temperature,and susceptibility to oxidation.In contrast,carbon-containing materials have emerged as promising candidates for high-temperature EWA applications,owing to their high melting point,low density,tunable dielectric loss mechanisms,and superior thermal stability.Unlike magnetic materials,carbon-based systems primarily dissipate electromagnetic energy through conductance loss,dipole polarization,and interfacial polarization,thereby avoiding performance degradation at elevated temperatures.However,several critical challenges remain,including insufficient oxidation resistance,mechanical reliability issues,and the need for stable impedance matching.To address these limitations,recent strategies such as defect engineering,heterointerface construction,and metamaterial design have been proposed to enhance thermal stability and functional performance.This review provides a systematic summary of recent advances in carbon-containing absorbers,with a focus on dielectric loss mechanisms,optimization strategies,and multiscale structural design principles.By elucidating the structure–property relationships of carbon materials,carbide ceramics,and novel carbon hybrids,this study aims to offer theoretical and technical guidance for the development of advanced high-temperature electromagnetic wave absorbers,thereby promoting their practical applications in aerospace and telecommunications.
基金supported by the National Natural Science Foundation of China(Nos.51773215,21774138)the Sino-German Mobility Programme(No.M-0424)+4 种基金Key Research Program of Frontier Sciences,Chinese Academy of Sciences(No.QYZDB-SSW-SLH036)Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2019297)Xiaoling Zuo is grateful for the financial supported by Science and Technology Fund of Guizhou Provinee,China(No.[2020]1 Y209)the Overseas Talents Selection Fund of Guizhou Province,China(No.[2020]11)Fund Project of Guizhou Minzu University,China(No.GZMU[2019]YB23).
文摘The concept of self-healing that involves a built-in ability to heal in response to damage wherever and whenever it occurs in a material,analogous to the healing process in living organisms,has emerged a couple of decades ago.Driven primarily by the demands for life-like materials and soft smart materials,therefore,the development of self-healing polymeric hydrogels has continually attracted the attention of the scientific community.Here,this review is intended to give an in-depth overview of the state-of-the-art advances in the field of self-healing polymeric hydrogels.Specifically,recently emerging trends in self-healing polymeric hydrogels are summarized,and notably,recommendations to endow these hydrogels with fascinating multi-functionalities including luminescence,conductivity/magnetism and shape memory etc are presented.To close,the current challenges and future opportunities in this field are also discussed.
基金This work was supported by the Swedish Foundation for Strategic Research(No. A302:132).
文摘By changing both the monomer composition and the polymer structure, we have varied the mechanical properties of resorbable polymers. The polymers were synthesized by ring-opening polymerization using L-lactide （LLA）, ε-caprolactone （εCL）, trimethylene carbonate （TMC） and 1,5-dioxepan-2-one （DXO） as monomers. Well-defined triblock copolymers, microblock copolymers and networks have been evaluated, and comparisons between them show that it is possible to tune the mechanical properties. Triblock copolymers with an amorphous middle block of poly（1,5-dioxepan-2- one） （PDXO） and semi-crystalline end-blocks of poly（ε-caprolactone） （PCL） were stronger and had a higher strain at break than triblock copolymers with poly（L-lactide） （PLLA） as end-blocks. Polymers with both DXO and TMC in the amorphous middle-block and PLLA as end-blocks showed a lower stress at break, but the material gained elasticity, a property which is very valuable in tissue engineering. Mechanical properties of networks, synthesized by a novel method, containing PDXO and PCL are also presented. Although it is difficult to compare them with the uncross-linked polymers, this is an additional way to modify and widen the properties.
文摘A new process for lamination of polymer films by 'bulk surface photografting' has been developed. The chemical component of the invention is that the curing of reactive solution between two substrates is initiated by the surface free radicals produced by aromatic ketones and surface-hydrogen of substrates. Using the new approach, two or more polymer films are bonded together by a grafted polymer network which is grafted to adjacent substrate surfaces. The technique has been applied to film substrates of different polymers such as polyolefins, polyesters, and polyamides which have abstractable hydrogens at the surface. The photolaminated film composites containing carrier films and an intermediate functional film of low permeability give strong laminates with high barrier properties, e.g, for oxygen and air.
文摘Nowadays, the use of natural fiber reinforced polymer-based composites is gradually increasing day by day for their many advantages for civil engineering construction applications. Due to their many advantages for polymer-based composite materials are widely used in civil construction, automobiles, aerospace, and many others. Natural fibers such as jute, kenaf, pineapple, sugarcane, hemp, oil palm, flax, and leaf, etc. are cheap, environmentally friendly, renewable, completely and partially biodegradable which can be utilized to obtain new high-performance polymer materials. These composites are having satisfactory mechanical properties (i.e. tensile properties, flexural stress-strain behavior, fracture toughness, and fracture strength) which make them more attractive than other composites. Due to easy availability and renewability, natural fibers can be used as an alternative of synthetic fibers as a reinforcing agent. The aim of this paper is to review different natural fibers reinforced based polymer composites with mechanical characterization, applications, also shows the opportunities, challenges and future demand of natural composite material towards civil applications.
文摘The use of composites in different sectors has become inevitable due to the enhancement in properties, reduction in the manufacturing cost and suitability to several applications. Among different classifications, polymeric composites are mainly focused on their use as structural components and the selection and composition of reinforcement play a vital role in determining the characteristics of the composite. Although composites are developed with man-made reinforcement in the beginning stage, in the present situation, natural reinforcements have proved excellent results in terms of properties. Hence, nowadays researches are mainly focused on the use of different natural fibers in different forms as reinforcements in polymeric composite. This work presents a brief overview on the properties of natural fiber and natural fiber reinforced composites which is an emerging area in polymer science. Interests in natural fiber is reasonable due to the advantages of these materials compared to others, such as synthetic fiber composites, including low environmental impact and low cost and support their potential to be used. Moreover, the disadvantage of the synthetic and fiber-glass as reinforcement, the use of natural fiber reinforced composite gained the attention of the young scientists, researchers, and engineers and are being exploited as a replacement for the conventional fiber such as glass, aramid, carbon etc. Natural fibers have been proven alternative to synthetic fiber in transportation such as automobiles, railway coaches and aerospace, military, building, packaging, consumer products and construction industries for ceiling paneling, partition boards etc. However, in development of these composites, some drawbacks have also emerged. In this paper, it has been tried to overview all of this together.
基金the support of the Swedish Energy Agency and Swedish Foundation for Strategic Research(SSF)for their financial supportthe China Scholarship Council(CSC)for its financial support。
文摘A new crosslinked polymer,called P65,with appropriate photo-electrochemical,opto-electronic,and thermal properties,has been designed and synthesized as an efficient,dopant-free,hole-transport material(HTM)for n-i-p type planar perovskite solar cells(PSCs).P65 is obtained from a low-cost and easily synthesized spiro[fluorene-9,90-xanthene]-30,60-diol(SFX-OH)-based monomer X65 through a freeradical polymerization reaction.The combination of a three-dimensional(3 D)SFX core unit,holetransport methoxydiphenylamine group,and crosslinked polyvinyl network provides P65 with good solubility and excellent film-forming properties.By employing P65 as a dopant-free hole-transport layer in conventional n-i-p type PSCs,a power conversion efficiency(PCE)of up to 17.7%is achieved.To the best of our knowledge,this is the first time a 3 D,crosslinked,polymeric dopant-free HTM has been reported for use in conventional n-i-p type PSCs.This study provides a new strategy for the future development of a 3 D crosslinked polymeric dopant-free HTM with a simple synthetic route and low-cost for commercial,large-scale applications in future PSCs.
基金supported by the National Natural Science Foundation of China(Grant No.61705090,11804117)Natural Science Foundation of Guangdong Province(2020A1515010853)。
文摘Thin films of perovskite deposited from solution inevitably introduce large number of defects,which serve as recombination centers and are detrimental for solar cell performance.Although many small molecules and polymers have been delicately designed to migrate defects of perovskite films,exploiting credible passivation agents based on natural materials would offer an alternative approach.Here,an ecofriendly and cost-effective biomaterial,ploy-L-lysine(PLL),is identified to effectively passivate the defects of perovskite films prepared by blade-coating.It is found that incorporation of a small amount(2.5 mg mL^(-1))of PLL significantly boosts the performance of printed devices,yielding a high efficiency of 19.45% with an increase in open-circuit voltage by up to 100 mV.Density functional theory calculations combined with X-ray photoelectron spectroscopy reveal that the functional groups(-NH2,-COOH)of PLL effectively migrate the Pb-I antisite defects via Pb-N coordination and suppress the formation of metallic Pb in the blade-coated perovskite film.This work suggests a viable avenue to exploit passivation agents from natural materials for preparation of high-quality perovskite layers for optoelectronic applications.
文摘The target of the present investigation is synthesis and characterization of an amphiphilic diblock copolymer with antibacterial property. Ring opening polymerization （ROP） of ε-caprolactone （CL） and tetrahydrofuran （THF） was carried out under inert atmosphere by using L-cysteine as a bridging agent in the presence of stannous octoate （SO） as a catalyst. The nano silver end capped diblock copolymer was synthesized by in situ method. Thus obtained nano silver end capped L-cysteine bridged diblock copolymer was characterized by various analytical methods like Fourier transform infrared （FTIR） spectroscopy, nuclear magnetic resonance （NMR） spectroscopy, circular dichroism （CD）, fluorescence spectroscopy, gel permeation chromatography （GPC）, X-ray photoelectron spectroscopy （XPS）, thermogravimetric analysis （TGA）, differential scanning calorimetry （DSC）, field emission scanning electron microscopy （FESEM）, high resolution transmission electron microscopy （HRTEM） and zeta potential. The antimicrobial property of the nano silver end capped diblock copolymer against e-coli was tested.
文摘Poly(phenylene oxide)/renewable polyamide 11 (PPO/PA11 20/80) blends toughened with glycidylmethacrylate grafted ethylene-n-octene copolymer (GEOC) were prepared in a co-rotating twin-screwextruder. The reaction between GEOC and PPO/PA11 blend was analyzed by gel content tests. Themorphology of PPO/PA11/GEOC blends was observed by scanning electron microscope. The SEMresults showed that PPO formed the continuous phase, though it is a minority component of blends. Withincreasing GEOC content from 5 to 15 wt% the morphology of the blends transformed from droplet-matrix toco-continuous structure, in which both PA11 and PPO phases are continuous. The blend with co-continuousmorphology had better mechanical properties than those with droplet-matrix morphology. The impactstrength of the PPO/PA11/GEOC blends was much higher compared to the one without GEOC as well asPA11 due to the compatibilizing effect, which was also proved by DSC analysis, rheological behavior (MFR,DMTA) and tensile properties.
文摘External magnetic field increases the photo-induced polymerization rate of styrene microemulsion.The type of photoinitiator plays an important role. The photoinitiators, used are dimethoxyphenyl acetophenone(DMPA), 1-hydroxycyclohexyl phenylketone (Irgacure 184) and dimethylhydroxyacetophenone (Darocur 1173). No magnetic effect was observed by using dibenzylketone (DBK) as photoinitiator. The molecular weight of the polymer is slightly affected by magnetic field. The influence of temperature has also been investigated.
