Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has ...Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has been difficult to strike a balance between the robustness and flexibility of coatings constructed by a single cross-linked network design.To overcome the conundrum,this innovative approach effectively combines two distinct cross-linked networks with unique functions,thus overcoming the challenge.Through a tightly interwoven structure comprised of added crosslinking sites,the coating achieves improved liquid repellency(WCA>100°,OSA<10°),increased durability(withstands 2,000 cycles of cotton wear),enhanced flexibility(endures 5,000 cycles of bending with a bending radius of 1 mm),and maintains high transparency(over 98%in the range of 410 nm to 760 nm).Additionally,the coating with remarkable adhesion can be applied to multiple substrates,enabling large-scale preparation and easy cycling coating,thus expanding its potential applications.The architecture of this fluoride-free dual cross-linked network not only advances liquid-repellent surfaces but also provides valuable insights for the development of eco-friendly materials in the future.展开更多
Although glass-ceramic(GC)scintillators offer improved performance by combining the advantages of both glass and crystalline materials,achieving an optimal balance between crystallinity and transparency through in sit...Although glass-ceramic(GC)scintillators offer improved performance by combining the advantages of both glass and crystalline materials,achieving an optimal balance between crystallinity and transparency through in situ crystallization in glass is still challenging.To address this problem,this work proposes a comprehensive strategy for regulating the heat treatment temperature,adjusting the amount of raw materials for precipitated nanocrystals,and modifying the glass network structure.Taking NaLuF_(4):Tb-based GC as an example,the results show that optimal conditions,including heat treatment at 700℃,a total molar percentage of 31.33%for NaF,LuF_(3),and TbF_(3),and a Si/Al ratio of 5.09,yield GC with 58%crystallinity and 90%transmittance at 542 nm,which are notably superior to those of most other reported high-performance oxyfluoride GC.The corresponding light yieldl detection limit,and image resolution are 10,200 photons-MeV^(-1),1.26 nGy-s^(-1),and 25.3 lp-mm,respectively,with the resolution exceeding values reported for most fluoride glass-and GC-based scintillators.These findings provide valuable insights into the design of high-performance GC scintillators with high crystallinity and transmittance.展开更多
Highly transparent and super-wettable nanocoatings for multifunctional applications with outstanding physical properties are in high demanded.However,such nanocoatings resistant to water invasion and Ultraviolet(UV)we...Highly transparent and super-wettable nanocoatings for multifunctional applications with outstanding physical properties are in high demanded.However,such nanocoatings resistant to water invasion and Ultraviolet(UV)weathering remain a significant challenge.In this work,physically durable coatings based on inorganic nanoparticles(NPs)and an organic segment(isocyanate-silane modified surfactant)have been synthesized via a sol-gel approach.It is noteworthy the isocyanate-silane with-NH-C=O-functional group creates a strong bonding between the highly hydrophilic surfactant and the inorganic NPs.This in-house synthesized organic segment can render the coating long-lasting wetting properties and resist to be washed away by water,while the inorganic NPs can form sturdy covalent bonds with the nano-scale hierarchical structure on the glazing substrate to improve the durability.This nanocoating demonstrates high transparency with superwetting property(water contact angle,WCA=4.4±0.3°),effective de-frosting performance.Water invasion or UV accelerated weathering tests do not significantly affect the self-cleaning performance of nanocoating.Physical properties,including coating adhesion,hardness,Young's modulus,and abrasion resistance are systematically investigated.Interestingly,this clear coating shows prominent infrared shielding property attributed to Antimony-doped tin oxide(Sb-doped SnO_(2))NPs.The developed nanocoating process is easy to scale up for larger areas that require multipurpose self-cleaning functions.展开更多
Near-infrared phosphor-converted light-emitting diodes(NIR pc-LEDs),one of the most promising NIR light sources,have garnered significant attention owing to their compact structure,long lifetime and energy conservatio...Near-infrared phosphor-converted light-emitting diodes(NIR pc-LEDs),one of the most promising NIR light sources,have garnered significant attention owing to their compact structure,long lifetime and energy conservation.Despite these advantages,commercial NIR pc-LEDs employing pseudotransmission configurations,where the NIR phosphor and silicone composites are directly coated on blue LED chips,suffer from critical limitations in thermal management that severely deteriorate their NIR output performance.To address these intrinsic limitations,we developed an oxygen-coordination-competitive crystallization strategy to engineer high-transparencyβ-Ga_(2)O_(3):Cr^(3+)glass-ceramics(GC).This strategy leveraged the strong oxygen affinity of Ga^(3+)ions,which drove the directional migration and recombination of Ga^(3+)and O^(2-)ions within the isolated[GaO_(4)]tetrahedral network during thermal processing.This controlled phase evolution enabled localized crystallization of theβ-Ga_(2)O_(3):Cr^(3+)nanocrystals while maintaining high transparency.The optimizedβ-Ga_(2)O_(3):Cr^(3+)GC(0.4 mm thickness)achieved remarkable 81.2%NIR transmittance,approaching internal quantum efficiency(IQE≈100%)and high thermal stability(89%@423 K).When this hightransparencyβ-Ga_(2)O_(3):Cr^(3+)GC was employed as the NIR conversion material,the NIR GC-converted LEDs(GCc-LEDs)achieved 568 mW of NIR output power at a 500 mA drive current with a photoelectric conversion efficiency of 13%.The demonstrated performance metrics of NIR GCc-LEDs positioned this technology as an ideal NIR illumination source for next-generation point-of-care diagnostics,intelligent night vision systems,and nondestructive testing applications.展开更多
In response to the development of the concepts of“carbon neutrality”and“carbon peak”,it is critical to developing materials with high near-infrared(NIR)solar reflectivity and high emissivity in the atmospheric tra...In response to the development of the concepts of“carbon neutrality”and“carbon peak”,it is critical to developing materials with high near-infrared(NIR)solar reflectivity and high emissivity in the atmospheric transparency window(ATW;8–13μm)to advance zero energy consumption radiative cooling technology.To regulate emission and reflection properties,a series of high-entropy rare earth stannate ceramics(HE-RE_(2)Sn_(2)O_(7):(Y_(0.2)La_(0.2)Nd_(0.2)Eu_(0.2)Gd_(0.2))_(2)Sn_(2)O_(7),(Y_(0.2)La_(0.2)Sm_(0.2)Eu_(0.2)Lu_(0.2))_(2)Sn_(2)O_(7),and(Y_(0.2)La_(0.2)Gd_(0.2)Yb_(0.2)Lu_(0.2))_(2)Sn_(2)O_(7))with severe lattice distortion were prepared using a solid phase reaction followed by a pressureless sintering method for the first time.Lattice distortion is accomplished by introducing rare earth elements with different cation radii and mass.The as-synthesized HE-RE_(2)Sn_(2)O_(7)ceramics possess high ATW emissivity(91.38%–95.41%),high NIR solar reflectivity(92.74%–97.62%),low thermal conductivity(1.080–1.619 W·m^(−1)·K^(−1)),and excellent chemical stability.On the one hand,the lattice distortion intensifies the asymmetry of the structural unit to cause a notable alteration in the electric dipole moment,ultimately enlarging the ATW emissivity.On the other hand,by selecting difficult excitation elements,HE-RE_(2)Sn_(2)O_(7),which has a wide band gap(Eg),exhibits high NIR solar reflectivity.Hence,the multi-component design can effectively enhance radiative cooling ability of HE-RE_(2)Sn_(2)O_(7)and provide a novel strategy for developing radiative cooling materials.展开更多
Traditional technologies for manufacturing microfluidic devices often involve the use of molds for polydimethylsiloxane(PDMS)casting generated from photolithography techniques,which are time-consuming,costly,and diffi...Traditional technologies for manufacturing microfluidic devices often involve the use of molds for polydimethylsiloxane(PDMS)casting generated from photolithography techniques,which are time-consuming,costly,and difficult to use in generating multilayered structure.As an alternative,3D printing allows rapid and cost-effective prototyping and customization of complex microfluidic structures.However,3Dprinted devices are typically opaque and are challenging to create small channels.Herein,we introduce a novel“programmable optical window bonding”3D printing method that incorporates the bonding of an optical window during the printing process,facilitating the fabrication of transparent microfluidic devices with high printing fidelity.Our approach allows direct and rapid manufacturing of complex microfluidic structure without the use of molds for PDMS casting.We successfully demonstrated the applications of this method by fabricating a variety of microfluidic devices,including perfusable chips for cell culture,droplet generators for spheroid formation,and high-resolution droplet microfluidic devices involving different channel width and height for rapid antibiotic susceptibility testing.Overall,our 3D printing method demonstrates a rapid and cost-effective approach for manufacturing microfluidic devices,particularly in the biomedical field,where rapid prototyping and high-quality optical analysis are crucial.展开更多
Ultrathin film-based transparent conductive oxides(TCOs)with a broad work function(WF)tunability are highly demanded for e cient energy conversion devices.However,reducing the film thickness below 50 nm is limited due...Ultrathin film-based transparent conductive oxides(TCOs)with a broad work function(WF)tunability are highly demanded for e cient energy conversion devices.However,reducing the film thickness below 50 nm is limited due to rapidly increasing resistance;furthermore,introducing dopants into TCOs such as indium tin oxide(ITO)to reduce the resistance decreases the transparency due to a trade-o between the two quantities.Herein,we demonstrate dopant-tunable ultrathin(≤50 nm)TCOs fabricated via electric field-driven metal implantation(m-TCOs;m=Ni,Ag,and Cu)without com-promising their innate electrical and optical properties.The m-TCOs exhibit a broad WF variation(0.97 eV),high transmittance in the UV to visible range(89–93%at 365 nm),and low sheet resistance(30–60Ωcm-2).Experimental and theoretical analyses show that interstitial metal atoms mainly a ect the change in the WF without substantial losses in optical transparency.The m-ITOs are employed as anode or cathode electrodes for organic light-emitting diodes(LEDs),inorganic UV LEDs,and organic photovoltaics for their universal use,leading to outstanding performances,even without hole injection layer for OLED through the WF-tailored Ni-ITO.These results verify the proposed m-TCOs enable e ective carrier transport and light extraction beyond the limits of traditional TCOs.展开更多
A family of new triphenylmethane(TPM)-based polyimides(PIs)containing bulky tert-butyldimethylsiloxy(TBS)side-groups(PI-TPMOSis)has been prepared by a post-polymerization modification via a simple silyl ether reaction...A family of new triphenylmethane(TPM)-based polyimides(PIs)containing bulky tert-butyldimethylsiloxy(TBS)side-groups(PI-TPMOSis)has been prepared by a post-polymerization modification via a simple silyl ether reaction of TPM-based PIs containing hydroxyl(OH)groups(PI-TPMOHs).The attachment of TBS side-groups in PI-TPMOSis can be achieved up to 100%,as confirmed by the 1H-NMR and IR spectra.Due to the presence of the TPM structure,PI-TPMOSi films still display the excellent thermal stability with high glass transition temperature(Tg)of 314–351°C and high degradation temperature(Td5%)of 480–501°C.It is quite remarkable that the introduction of TBS side-groups into PI-TPMOSi chains results in more superior optical,dielectric and solubility properties in comparison with the precursor PI-TPMOH films,probably due to the reductions of the packing density and charge-transfer complexes(CTCs)formation.The optical transmittance at 400 nm(T400)of PI-TPMOSi films is significantly increased from 45.3%–68.8%to 75.4%–81.6%of the precursor PI-TPMOH films.The dielectric constant(Dk)and dissipation factor(Df)at 1 MHz of PI-TPMOSi films are reduced from 4.11–4.40 and 0.00159–0.00235 to 2.61–2.92 and 0.00125–0.00171 of the precursor PI-TPMOH films,respectively.Combining the molecular design and simple preparation method,this study provides an effective approach for enhancement of various properties of PI films for microelectronic and photoelectric engineering applications.展开更多
Size-scalable X-ray scintillators with high transparency and robust photon yield allow for imaging large objects with greater precision and detail.Solution-processable scintillators,typically crafted from quantum dots...Size-scalable X-ray scintillators with high transparency and robust photon yield allow for imaging large objects with greater precision and detail.Solution-processable scintillators,typically crafted from quantum dots(QDs),are promising candidates for highly efficient scintillation applications.However,the restricted size and low transparency in QD-based scintillators lead to less efficient X-ray imaging for large objects requiring high resolution.Herein,we demonstrate a meter-scale ZnO QD scintillator with a visible range transmittance exceeding 96%,featuring bright singlet-triplet hybrid self-trapping excitons(STEs).The quantum yields(QYs)of singlet excitons and triplet excitons are 44.7%and 26.3%.Benefiting from a large Stokes shift and bright triplet excitons,the scintillator has a negligible self-absorption and elevated photon yields.Additionally,the scintillator exhibits exchange invariance,demonstrating identical optical performance upon exchanging the coordinates(r)of the QDs.Featuring bright singlet-triplet hybrid STEs and high transparency,the scintillator achieves high resolution X-ray imaging of 42-line pairs per millimeter(42 lp mm^(-1))at a meter scale.Moreover,demonstrations of 5000 cm^(2) X-ray imaging and real-time dynamic X-ray imaging are presented.The lowest detectable dose rate for X-ray detection is as low as 37.63±0.4 nGy s^(-1).This work presents a novel sizable and transparent scintillator with bright singlet-triplet hybrid STEs,showcasing their potential in high-resolution and sizable object X-ray imaging.展开更多
基金financially supported by the National Natu-ral Science Foundation of China(Nos.22375047,22378068,and 22075046)the Natural Science Foundation of Fujian Province(No.2022J01568)+2 种基金the National Key Research and Development Program of China(Nos.2022YFB3804905 and 2022YFB3804900)China Postdoctoral Science Foundation(No.2023M743437)start-up funding from Wenzhou Institute,University of Chinese Academy of Sciences(No.WIUCASQD2019002).
文摘Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has been difficult to strike a balance between the robustness and flexibility of coatings constructed by a single cross-linked network design.To overcome the conundrum,this innovative approach effectively combines two distinct cross-linked networks with unique functions,thus overcoming the challenge.Through a tightly interwoven structure comprised of added crosslinking sites,the coating achieves improved liquid repellency(WCA>100°,OSA<10°),increased durability(withstands 2,000 cycles of cotton wear),enhanced flexibility(endures 5,000 cycles of bending with a bending radius of 1 mm),and maintains high transparency(over 98%in the range of 410 nm to 760 nm).Additionally,the coating with remarkable adhesion can be applied to multiple substrates,enabling large-scale preparation and easy cycling coating,thus expanding its potential applications.The architecture of this fluoride-free dual cross-linked network not only advances liquid-repellent surfaces but also provides valuable insights for the development of eco-friendly materials in the future.
基金supported by the National Natural Science Foundation of China(Nos.12304442,52272141,51972060,12074068,52102159,and22103013)the Professional Development Program for University Teachers in Zhejiang Province(No.FX2024075)the Natural Science Foundation of Fujian Province(Nos.2024J02014,2022J05091,2021J06021,and 2021J01190).
文摘Although glass-ceramic(GC)scintillators offer improved performance by combining the advantages of both glass and crystalline materials,achieving an optimal balance between crystallinity and transparency through in situ crystallization in glass is still challenging.To address this problem,this work proposes a comprehensive strategy for regulating the heat treatment temperature,adjusting the amount of raw materials for precipitated nanocrystals,and modifying the glass network structure.Taking NaLuF_(4):Tb-based GC as an example,the results show that optimal conditions,including heat treatment at 700℃,a total molar percentage of 31.33%for NaF,LuF_(3),and TbF_(3),and a Si/Al ratio of 5.09,yield GC with 58%crystallinity and 90%transmittance at 542 nm,which are notably superior to those of most other reported high-performance oxyfluoride GC.The corresponding light yieldl detection limit,and image resolution are 10,200 photons-MeV^(-1),1.26 nGy-s^(-1),and 25.3 lp-mm,respectively,with the resolution exceeding values reported for most fluoride glass-and GC-based scintillators.These findings provide valuable insights into the design of high-performance GC scintillators with high crystallinity and transmittance.
基金The Hong Kong University of Science and Technology(Grants#:R9365,F0776,and F0782).
文摘Highly transparent and super-wettable nanocoatings for multifunctional applications with outstanding physical properties are in high demanded.However,such nanocoatings resistant to water invasion and Ultraviolet(UV)weathering remain a significant challenge.In this work,physically durable coatings based on inorganic nanoparticles(NPs)and an organic segment(isocyanate-silane modified surfactant)have been synthesized via a sol-gel approach.It is noteworthy the isocyanate-silane with-NH-C=O-functional group creates a strong bonding between the highly hydrophilic surfactant and the inorganic NPs.This in-house synthesized organic segment can render the coating long-lasting wetting properties and resist to be washed away by water,while the inorganic NPs can form sturdy covalent bonds with the nano-scale hierarchical structure on the glazing substrate to improve the durability.This nanocoating demonstrates high transparency with superwetting property(water contact angle,WCA=4.4±0.3°),effective de-frosting performance.Water invasion or UV accelerated weathering tests do not significantly affect the self-cleaning performance of nanocoating.Physical properties,including coating adhesion,hardness,Young's modulus,and abrasion resistance are systematically investigated.Interestingly,this clear coating shows prominent infrared shielding property attributed to Antimony-doped tin oxide(Sb-doped SnO_(2))NPs.The developed nanocoating process is easy to scale up for larger areas that require multipurpose self-cleaning functions.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52172083,62275105,12304443,52473262,and 52402192)the Zhejiang Province Key R&D Program:Vanguard and Leading Geese Projects(Grant No.2024C01190)+6 种基金the International Science&Technology Cooperation Program of Guangdong(Grant No.2021A0505030078)the Guangzhou Key Research and Development Program(Grant No.2023B03J1239)the Program for Innovative Research Team in University of Education System of Guangzhou(Grant No.202235404)financially supported by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515110463)the Significant Science and Technology Projects of LongMen Laboratory in Henan Province(Grant No.231100220100)the Key Research and Development Program of Henan Province(Grant No.231111222200)the Key Scientific Research Projects of Higher Education Institutions in Henan Province(Grant No.25CY025)。
文摘Near-infrared phosphor-converted light-emitting diodes(NIR pc-LEDs),one of the most promising NIR light sources,have garnered significant attention owing to their compact structure,long lifetime and energy conservation.Despite these advantages,commercial NIR pc-LEDs employing pseudotransmission configurations,where the NIR phosphor and silicone composites are directly coated on blue LED chips,suffer from critical limitations in thermal management that severely deteriorate their NIR output performance.To address these intrinsic limitations,we developed an oxygen-coordination-competitive crystallization strategy to engineer high-transparencyβ-Ga_(2)O_(3):Cr^(3+)glass-ceramics(GC).This strategy leveraged the strong oxygen affinity of Ga^(3+)ions,which drove the directional migration and recombination of Ga^(3+)and O^(2-)ions within the isolated[GaO_(4)]tetrahedral network during thermal processing.This controlled phase evolution enabled localized crystallization of theβ-Ga_(2)O_(3):Cr^(3+)nanocrystals while maintaining high transparency.The optimizedβ-Ga_(2)O_(3):Cr^(3+)GC(0.4 mm thickness)achieved remarkable 81.2%NIR transmittance,approaching internal quantum efficiency(IQE≈100%)and high thermal stability(89%@423 K).When this hightransparencyβ-Ga_(2)O_(3):Cr^(3+)GC was employed as the NIR conversion material,the NIR GC-converted LEDs(GCc-LEDs)achieved 568 mW of NIR output power at a 500 mA drive current with a photoelectric conversion efficiency of 13%.The demonstrated performance metrics of NIR GCc-LEDs positioned this technology as an ideal NIR illumination source for next-generation point-of-care diagnostics,intelligent night vision systems,and nondestructive testing applications.
基金the Lingchuang Research Project of China National Nuclear Co.,the National Key R&D Program of China(No.2022YFB3504302)the Fujian Provincial Natural Fund Project(No.2021J05101)+1 种基金the Young Elite Scientists Sponsorship Program by CAST(No.YESS20210336)the XMIREM autonomously deployment project(No.2023GG03).
文摘In response to the development of the concepts of“carbon neutrality”and“carbon peak”,it is critical to developing materials with high near-infrared(NIR)solar reflectivity and high emissivity in the atmospheric transparency window(ATW;8–13μm)to advance zero energy consumption radiative cooling technology.To regulate emission and reflection properties,a series of high-entropy rare earth stannate ceramics(HE-RE_(2)Sn_(2)O_(7):(Y_(0.2)La_(0.2)Nd_(0.2)Eu_(0.2)Gd_(0.2))_(2)Sn_(2)O_(7),(Y_(0.2)La_(0.2)Sm_(0.2)Eu_(0.2)Lu_(0.2))_(2)Sn_(2)O_(7),and(Y_(0.2)La_(0.2)Gd_(0.2)Yb_(0.2)Lu_(0.2))_(2)Sn_(2)O_(7))with severe lattice distortion were prepared using a solid phase reaction followed by a pressureless sintering method for the first time.Lattice distortion is accomplished by introducing rare earth elements with different cation radii and mass.The as-synthesized HE-RE_(2)Sn_(2)O_(7)ceramics possess high ATW emissivity(91.38%–95.41%),high NIR solar reflectivity(92.74%–97.62%),low thermal conductivity(1.080–1.619 W·m^(−1)·K^(−1)),and excellent chemical stability.On the one hand,the lattice distortion intensifies the asymmetry of the structural unit to cause a notable alteration in the electric dipole moment,ultimately enlarging the ATW emissivity.On the other hand,by selecting difficult excitation elements,HE-RE_(2)Sn_(2)O_(7),which has a wide band gap(Eg),exhibits high NIR solar reflectivity.Hence,the multi-component design can effectively enhance radiative cooling ability of HE-RE_(2)Sn_(2)O_(7)and provide a novel strategy for developing radiative cooling materials.
文摘Traditional technologies for manufacturing microfluidic devices often involve the use of molds for polydimethylsiloxane(PDMS)casting generated from photolithography techniques,which are time-consuming,costly,and difficult to use in generating multilayered structure.As an alternative,3D printing allows rapid and cost-effective prototyping and customization of complex microfluidic structures.However,3Dprinted devices are typically opaque and are challenging to create small channels.Herein,we introduce a novel“programmable optical window bonding”3D printing method that incorporates the bonding of an optical window during the printing process,facilitating the fabrication of transparent microfluidic devices with high printing fidelity.Our approach allows direct and rapid manufacturing of complex microfluidic structure without the use of molds for PDMS casting.We successfully demonstrated the applications of this method by fabricating a variety of microfluidic devices,including perfusable chips for cell culture,droplet generators for spheroid formation,and high-resolution droplet microfluidic devices involving different channel width and height for rapid antibiotic susceptibility testing.Overall,our 3D printing method demonstrates a rapid and cost-effective approach for manufacturing microfluidic devices,particularly in the biomedical field,where rapid prototyping and high-quality optical analysis are crucial.
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government under Grant No.2016R1A3B1908249。
文摘Ultrathin film-based transparent conductive oxides(TCOs)with a broad work function(WF)tunability are highly demanded for e cient energy conversion devices.However,reducing the film thickness below 50 nm is limited due to rapidly increasing resistance;furthermore,introducing dopants into TCOs such as indium tin oxide(ITO)to reduce the resistance decreases the transparency due to a trade-o between the two quantities.Herein,we demonstrate dopant-tunable ultrathin(≤50 nm)TCOs fabricated via electric field-driven metal implantation(m-TCOs;m=Ni,Ag,and Cu)without com-promising their innate electrical and optical properties.The m-TCOs exhibit a broad WF variation(0.97 eV),high transmittance in the UV to visible range(89–93%at 365 nm),and low sheet resistance(30–60Ωcm-2).Experimental and theoretical analyses show that interstitial metal atoms mainly a ect the change in the WF without substantial losses in optical transparency.The m-ITOs are employed as anode or cathode electrodes for organic light-emitting diodes(LEDs),inorganic UV LEDs,and organic photovoltaics for their universal use,leading to outstanding performances,even without hole injection layer for OLED through the WF-tailored Ni-ITO.These results verify the proposed m-TCOs enable e ective carrier transport and light extraction beyond the limits of traditional TCOs.
基金supported by the National Natural Science Foundation of China(Nos.52203014,52103010 and 52003200)the Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515110767,2022A1515010969,2020A1515110897 and 2023A1515010999)+2 种基金the Open Fund for Key Lab of Guangdong High Property and Functional Macromolecular Materials,China(No.20220601)Guangdong Provincial Department of Education Featured Innovation Project(No.2021KTSCX138)the Science Foundation for Young Research Groups of Wuyi University(Nos.2020AL016 and 2019AL019).
文摘A family of new triphenylmethane(TPM)-based polyimides(PIs)containing bulky tert-butyldimethylsiloxy(TBS)side-groups(PI-TPMOSis)has been prepared by a post-polymerization modification via a simple silyl ether reaction of TPM-based PIs containing hydroxyl(OH)groups(PI-TPMOHs).The attachment of TBS side-groups in PI-TPMOSis can be achieved up to 100%,as confirmed by the 1H-NMR and IR spectra.Due to the presence of the TPM structure,PI-TPMOSi films still display the excellent thermal stability with high glass transition temperature(Tg)of 314–351°C and high degradation temperature(Td5%)of 480–501°C.It is quite remarkable that the introduction of TBS side-groups into PI-TPMOSi chains results in more superior optical,dielectric and solubility properties in comparison with the precursor PI-TPMOH films,probably due to the reductions of the packing density and charge-transfer complexes(CTCs)formation.The optical transmittance at 400 nm(T400)of PI-TPMOSi films is significantly increased from 45.3%–68.8%to 75.4%–81.6%of the precursor PI-TPMOH films.The dielectric constant(Dk)and dissipation factor(Df)at 1 MHz of PI-TPMOSi films are reduced from 4.11–4.40 and 0.00159–0.00235 to 2.61–2.92 and 0.00125–0.00171 of the precursor PI-TPMOH films,respectively.Combining the molecular design and simple preparation method,this study provides an effective approach for enhancement of various properties of PI films for microelectronic and photoelectric engineering applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.62075198,11974317,61804136)the Outstanding Youth Foundation of Henan(Grant nos.222300420087)S.-Y.S.acknowledges the support from the National Postdoctoral Program for Innovative Talents(Grant No.BX20240337).
文摘Size-scalable X-ray scintillators with high transparency and robust photon yield allow for imaging large objects with greater precision and detail.Solution-processable scintillators,typically crafted from quantum dots(QDs),are promising candidates for highly efficient scintillation applications.However,the restricted size and low transparency in QD-based scintillators lead to less efficient X-ray imaging for large objects requiring high resolution.Herein,we demonstrate a meter-scale ZnO QD scintillator with a visible range transmittance exceeding 96%,featuring bright singlet-triplet hybrid self-trapping excitons(STEs).The quantum yields(QYs)of singlet excitons and triplet excitons are 44.7%and 26.3%.Benefiting from a large Stokes shift and bright triplet excitons,the scintillator has a negligible self-absorption and elevated photon yields.Additionally,the scintillator exhibits exchange invariance,demonstrating identical optical performance upon exchanging the coordinates(r)of the QDs.Featuring bright singlet-triplet hybrid STEs and high transparency,the scintillator achieves high resolution X-ray imaging of 42-line pairs per millimeter(42 lp mm^(-1))at a meter scale.Moreover,demonstrations of 5000 cm^(2) X-ray imaging and real-time dynamic X-ray imaging are presented.The lowest detectable dose rate for X-ray detection is as low as 37.63±0.4 nGy s^(-1).This work presents a novel sizable and transparent scintillator with bright singlet-triplet hybrid STEs,showcasing their potential in high-resolution and sizable object X-ray imaging.
