Vacuum-ultraviolet(VUV)radiation is high-energy UV radiation with a wavelength of 100-200 nm capable of decomposing/mineralizing hazardous emerging organic pollutants(EPs)in water through direct photolysis and/or by g...Vacuum-ultraviolet(VUV)radiation is high-energy UV radiation with a wavelength of 100-200 nm capable of decomposing/mineralizing hazardous emerging organic pollutants(EPs)in water through direct photolysis and/or by generating reactive free radicals(RFRs)during photolysis.However,due to the unsatisfactory photoelectric conversion rate,strong absorption by oxygen and water molecules,and other characteristics of VUV radiation,its application and development are hindered,leading to misconceptions regarding high energy consumption and insufficient free radical yield.The objectives of our assessment in this review are as follows:The illumination of the photochemical characteristics of VUV and the reactivity of aqueous solutions.Summarization of accurate UV dose and energy evaluation criteria.Comparison and analysis of the photochemical mechanisms and reaction kinetics of different types of EPs via VUV direct photolysis,as well as the interference origins of typical substrates in water for VUV decontamination.We found that quantities typically reported in VUV photochemical reactions of engineered systems are underreported in low-pressure mercury lamp(LPUV)photochemical reactions,especially a quantitative indicator of the species or energy that induces a chemical reaction.The absence of these quantities has made it difficult to assess the fundamental performance of VUV photolysis fully compared with that of UV-C.Some studies have sought to optimize VUV-advanced reduction processes(VUV-ARP)or VUV reactor treatment of these contaminants;however,an abundant evaluation of the reaction origins and processes between VUV-derived main RFRs and reactants(H_(2)O,O_(2),organic matter,inorganic ions,etc.)is essential,cause these scientific elements will provide the possibility to break the application gap for VUV in the field of EPs treating.Overall,the data compilation,analysis,and research recommendations provided in this review will form the basis for all photochemical reactions initiated by VUV radiation with water as the backing agent.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
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
Conventional polyethylene(PE)fibers face limitations in large-scale industrial applications due to their poor thermal stability and inherent hydrophobicity,which restrict processing temperatures and dyeability,especia...Conventional polyethylene(PE)fibers face limitations in large-scale industrial applications due to their poor thermal stability and inherent hydrophobicity,which restrict processing temperatures and dyeability,especially in blended fabric production.In this research,a one-step ultraviolet(UV)irradiation technology was employed to modify medium molecular weight PE fibers through simultaneous crosslinking and grafting modifications,aiming to enhance their thermal stability and hydrophilicity.The modification employed a cost-effective,UV-initiated crosslinking system consisting of benzophenone(BP)as the photoinitiator and triallyl isocyanurate(TAIC)as the cocrosslinker.Acrylic acid(AA)was selected as the grafting monomer.These modifiers were thoroughly mixed with the PE matrix in a liquid-phase environment,and the mixture was melt-spun into fibers.The resulting fibers were then subjected to UV irradiation,which triggered the crosslinking and grafting reactions.The effects of the mass fraction of each component and irradiation parameters on modification efficacy were systematically investigated,followed by a comprehensive characterization of the modified PE fibers.The modified PE fibers achieved optimal thermal stability under the following conditions:2.0%mass fractions for both BP and TAIC,a UV irradiation intensity of 2000 mW/cm^(2),and an equivalent irradiation time of 60 s.This synergistic modification approach enables the fibers to maintain superior morphological integrity and mechanical performance when exposed to elevated temperatures ranging from 130 to 150℃.Meanwhile,an AA grafting mass fraction of 2.0%maximizes hydrophilicity with minimal impact on other properties,as evidenced by a dramatic reduction in the water contact angle(WCA)from 105.0°(hydrophobic)to 48.4°(hydrophilic).These improvements confirm the effectiveness of the modification strategy in synergistically enhancing both thermal stability and hydrophilicity of PE fibers.展开更多
A monolithic integrated full-wave bridge rectifier consisted of horizontal Schottky-barrier diodes(SBD)is prepared based on 100 nm ultra-thin β-Ga_(2)O_(3)and demonstrated the solar-blind UV(SUV)light-modulated chara...A monolithic integrated full-wave bridge rectifier consisted of horizontal Schottky-barrier diodes(SBD)is prepared based on 100 nm ultra-thin β-Ga_(2)O_(3)and demonstrated the solar-blind UV(SUV)light-modulated characteristics.Under SUV light illumination,the rectifier has the excellent full-wave rectification characteristics for the AC input signals of 5,12,and 24 V with different frequencies.Further,experimental results confirmed the feasibility of continuously tuning the rectified output through SUV light-encoding.This work provides valuable insights for the development of optically programmable Ga_(2)O_(3)ACDC converters.展开更多
Polymer nanocomposite coatings(PNCCs)are unprecedented generation of coatings engineered for displaying inexpensive and brilliant functional surface coatings with eminent corrosion guard,mechanical resistance,antimicr...Polymer nanocomposite coatings(PNCCs)are unprecedented generation of coatings engineered for displaying inexpensive and brilliant functional surface coatings with eminent corrosion guard,mechanical resistance,antimicrobial,chemical durability,electrical insulation,and UV aging features.Due to their widely anticipation in petroleum,applications in building,conveyance,aerospace,electronics,automobiles and energy,these multi-functional coatings have a tremendous leverage in human life,all technological and scientific subjects.Numerous applications have been made for multilateral polymers like polyurethane(PU),epoxy(EP),polyaniline(PANI)conductive polymer,polypyrrole(PPy),and etc,on various metallic surfaces especially,carbon steel substrate owing to their excellent resistance properties.Practically,nanomaterials can possess potential in the all-interdisciplinary domains of materials science and engineering,chemical and physical sciences,biological and health sciences.As known,the designed polymer nanocomposite coating paradigm is fundamentally constituted from polymer or resin as a vehicle and inorganic nanofillers(nanoparticles and nanocomposites).Some commercialized and excessively employed nanocontainers in polymer nanocomposite coating formulations,like ZnO,TiO_(2),carbon nanotubes(CNTs),clay,SiO_(2),Al_(2)O_(3),graphene,GO,CeO_(2),ZrO_(2),FeTiO_(3),etc were discussed.The current review covered the chemistry and potential applications of the largest utilized multifunctional polymer nanocomposite coatings such as EP,PU and other considerable PNCCs.Lately,a titanic attention was made for epoxy nanocomposites because of their distinct physicochemical characteristics,which result from the combined qualities of the nanoparticles and polymer material unity.In addition,the author incorporated some of his scientific contributions in this area represented in construction of innovative functional polymer nanocomposites for a variety of uses with high economic,industrial impacts and future orientation.Furthermore,some newly published applications of polymer nanocomposite coatings were incorporated and discussed.展开更多
基金supported by the National Key R&D Program of China(No.2023YFC3210100).
文摘Vacuum-ultraviolet(VUV)radiation is high-energy UV radiation with a wavelength of 100-200 nm capable of decomposing/mineralizing hazardous emerging organic pollutants(EPs)in water through direct photolysis and/or by generating reactive free radicals(RFRs)during photolysis.However,due to the unsatisfactory photoelectric conversion rate,strong absorption by oxygen and water molecules,and other characteristics of VUV radiation,its application and development are hindered,leading to misconceptions regarding high energy consumption and insufficient free radical yield.The objectives of our assessment in this review are as follows:The illumination of the photochemical characteristics of VUV and the reactivity of aqueous solutions.Summarization of accurate UV dose and energy evaluation criteria.Comparison and analysis of the photochemical mechanisms and reaction kinetics of different types of EPs via VUV direct photolysis,as well as the interference origins of typical substrates in water for VUV decontamination.We found that quantities typically reported in VUV photochemical reactions of engineered systems are underreported in low-pressure mercury lamp(LPUV)photochemical reactions,especially a quantitative indicator of the species or energy that induces a chemical reaction.The absence of these quantities has made it difficult to assess the fundamental performance of VUV photolysis fully compared with that of UV-C.Some studies have sought to optimize VUV-advanced reduction processes(VUV-ARP)or VUV reactor treatment of these contaminants;however,an abundant evaluation of the reaction origins and processes between VUV-derived main RFRs and reactants(H_(2)O,O_(2),organic matter,inorganic ions,etc.)is essential,cause these scientific elements will provide the possibility to break the application gap for VUV in the field of EPs treating.Overall,the data compilation,analysis,and research recommendations provided in this review will form the basis for all photochemical reactions initiated by VUV radiation with water as the backing agent.
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(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.
文摘Conventional polyethylene(PE)fibers face limitations in large-scale industrial applications due to their poor thermal stability and inherent hydrophobicity,which restrict processing temperatures and dyeability,especially in blended fabric production.In this research,a one-step ultraviolet(UV)irradiation technology was employed to modify medium molecular weight PE fibers through simultaneous crosslinking and grafting modifications,aiming to enhance their thermal stability and hydrophilicity.The modification employed a cost-effective,UV-initiated crosslinking system consisting of benzophenone(BP)as the photoinitiator and triallyl isocyanurate(TAIC)as the cocrosslinker.Acrylic acid(AA)was selected as the grafting monomer.These modifiers were thoroughly mixed with the PE matrix in a liquid-phase environment,and the mixture was melt-spun into fibers.The resulting fibers were then subjected to UV irradiation,which triggered the crosslinking and grafting reactions.The effects of the mass fraction of each component and irradiation parameters on modification efficacy were systematically investigated,followed by a comprehensive characterization of the modified PE fibers.The modified PE fibers achieved optimal thermal stability under the following conditions:2.0%mass fractions for both BP and TAIC,a UV irradiation intensity of 2000 mW/cm^(2),and an equivalent irradiation time of 60 s.This synergistic modification approach enables the fibers to maintain superior morphological integrity and mechanical performance when exposed to elevated temperatures ranging from 130 to 150℃.Meanwhile,an AA grafting mass fraction of 2.0%maximizes hydrophilicity with minimal impact on other properties,as evidenced by a dramatic reduction in the water contact angle(WCA)from 105.0°(hydrophobic)to 48.4°(hydrophilic).These improvements confirm the effectiveness of the modification strategy in synergistically enhancing both thermal stability and hydrophilicity of PE fibers.
基金supported by Natural Science Basic Research Program of Shaanxi Province of China(Grant No.2023JCYB574)National Natural Science Foundation of China(Grant No.62204203)。
文摘A monolithic integrated full-wave bridge rectifier consisted of horizontal Schottky-barrier diodes(SBD)is prepared based on 100 nm ultra-thin β-Ga_(2)O_(3)and demonstrated the solar-blind UV(SUV)light-modulated characteristics.Under SUV light illumination,the rectifier has the excellent full-wave rectification characteristics for the AC input signals of 5,12,and 24 V with different frequencies.Further,experimental results confirmed the feasibility of continuously tuning the rectified output through SUV light-encoding.This work provides valuable insights for the development of optically programmable Ga_(2)O_(3)ACDC converters.
文摘Polymer nanocomposite coatings(PNCCs)are unprecedented generation of coatings engineered for displaying inexpensive and brilliant functional surface coatings with eminent corrosion guard,mechanical resistance,antimicrobial,chemical durability,electrical insulation,and UV aging features.Due to their widely anticipation in petroleum,applications in building,conveyance,aerospace,electronics,automobiles and energy,these multi-functional coatings have a tremendous leverage in human life,all technological and scientific subjects.Numerous applications have been made for multilateral polymers like polyurethane(PU),epoxy(EP),polyaniline(PANI)conductive polymer,polypyrrole(PPy),and etc,on various metallic surfaces especially,carbon steel substrate owing to their excellent resistance properties.Practically,nanomaterials can possess potential in the all-interdisciplinary domains of materials science and engineering,chemical and physical sciences,biological and health sciences.As known,the designed polymer nanocomposite coating paradigm is fundamentally constituted from polymer or resin as a vehicle and inorganic nanofillers(nanoparticles and nanocomposites).Some commercialized and excessively employed nanocontainers in polymer nanocomposite coating formulations,like ZnO,TiO_(2),carbon nanotubes(CNTs),clay,SiO_(2),Al_(2)O_(3),graphene,GO,CeO_(2),ZrO_(2),FeTiO_(3),etc were discussed.The current review covered the chemistry and potential applications of the largest utilized multifunctional polymer nanocomposite coatings such as EP,PU and other considerable PNCCs.Lately,a titanic attention was made for epoxy nanocomposites because of their distinct physicochemical characteristics,which result from the combined qualities of the nanoparticles and polymer material unity.In addition,the author incorporated some of his scientific contributions in this area represented in construction of innovative functional polymer nanocomposites for a variety of uses with high economic,industrial impacts and future orientation.Furthermore,some newly published applications of polymer nanocomposite coatings were incorporated and discussed.
