Polyaniline(PANi)hydrogels have a wide range of applications in artificial skin,flexible robotics,and movement monitoring.Nevertheless,limited by the modulus mismatch between rigid PANi and the soft hydrogel matrix,th...Polyaniline(PANi)hydrogels have a wide range of applications in artificial skin,flexible robotics,and movement monitoring.Nevertheless,limited by the modulus mismatch between rigid PANi and the soft hydrogel matrix,the high strength and toughness of the PANi hydrogel are mutually exclusive.Although the introduction of sacrificial bonds into the hydrogel network can alleviate this contradiction to a certain extent,it always causes pronounced energy hysteresis during hydrogel deformation.Inspired by the energy storage and release of macroscopic springs,in this work,we propose a molecular entanglement approach for the fabrication of PANi hydrogels featuring high toughness and low hysteresis,where flexible poly(ethylene glycol)(PEG)is entangled with chemically cross-linked poly(acrylic acid)(PAA)as a hydrogel matrix,and rigid PANi as a conductive filler.The resultant PAA/PEG/PANi hydrogel exhibited high mechanical properties(fracture strength of 0.75 MPa and toughness of 4.81 MJ·m^(-3))and a low energy dissipation ratio(28.2%when stretching to 300%).Moreover,the PAA/PEG/PANi hydrogel possesses a good electrical response to external forces and can be employed as a strain sensor to monitor human joint movements by producing specific electrical signals.This work provides a straightforward strategy for preparing tough conductive PANi hydrogels with low hysteresis,showing potential for the development of healthcare devices.展开更多
Because of their better chemical stability and fascinating anisotropic characteristics,Dion-Jacobson(DJ)-layered halide perovskites,which owe crystallographic two-dimensional structures,have fascinated growing attenti...Because of their better chemical stability and fascinating anisotropic characteristics,Dion-Jacobson(DJ)-layered halide perovskites,which owe crystallographic two-dimensional structures,have fascinated growing attention for solar devices.DJ-layered halide perovskites have special structural and photoelectronic features that allow the van der Waals gap to be eliminated or reduced.DJ-layered halide perovskites have improved photophysical characteristics,resulting in improved photovoltaic performance.Nevertheless,owing to the nature of the solution procedure and the fast crystal development of DJ perovskite thin layers,the precursor compositions and processing circumstances can cause a variety of defects to occur.The application of additives can impact DJ perovskite crystallization and film generation,trap passivation in the bulk and/or at the surface,interface structure,and energetic tuning.This study discusses recent developments in additive engineering for DJ multilayer halide perovskite film production.Several additive-assisted bulk and interface optimization methodologies are summarized.Lastly,an overview of research developments in additive engineering in the production of DJ-layered halide perovskite solar cells is offered.展开更多
Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-...Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-NTA)initiated by amino-terminated PEG.The self-assemblies of three PEG-b-PMeSPG copolymers with different PMeSPG block lengths were first prepared by nanoprecipitation method using THF and DMF,respectively,as the organic solvent,and their morphologies were studied by Cryo-EM and DLS.To prepare polymersomes loaded with glucose oxidase(GOx),double emulsion method followed by extrusion treatment was employed.The oxidation-responsive disruption of polymersomes was achieved upon the introduction of glucose because of the oxidants generated insitu by GOx/glucose.展开更多
Interfacial defects and energy barrier would result in serious interfacial non-radiative recombination losses.In addition,the quality of perovskite films is highly dependent on deposition substrates.Consequently,there...Interfacial defects and energy barrier would result in serious interfacial non-radiative recombination losses.In addition,the quality of perovskite films is highly dependent on deposition substrates.Consequently,there is an urgent desire to develop multifunctional interface modulators to manage the interface between electron transport layer and perovskite layer.Here,we report a multifunctional buried interface modulation strategy that 4-fluoro-phenylammonium tetrafluoroborate (FBABF_(4)) consisting of simultaneously fluorinated anion and cation is inserted between SnO_(2)layer and perovskite layer.It is uncovered by time-of-flight secondary ion mass spectroscopy that the anion and cation in modifier are mainly located at this interface,which is put down to coordination bond of the fluorine atom on BF_(4)^(-) with SnO_(2),and the hydrogen bond of the fluorine atom on FBA^(+) with formamidinium.This suggests that simultaneous fluorination of anion and cation in the ionic liquid molecule is of crucial importance to ameliorate interfacial contact through chemical linker.The interface modification approach enables the realization of interfacial defect passivation,interfacial energy band alignment modulation,and perovskite crystallization manipulation,which are translated into enhanced efficiency and stability as well as significantly suppressed hysteresis.The multiple functions of FBABF_(4) endow the modified solar cells excellent photovoltaic performance with an efficiency exceeding 23%along with appealing long-term stability.This work highlights the critical role of fluorination strategy in engineering multifunctional organic salt modulators for improving interfacial contact.展开更多
Fluorescent vesicles have recently attracted increasing attention because of their potential applications in bioimaging,diagnostics, and theranostics, for example, in vivo study of the delivery and the distribution of...Fluorescent vesicles have recently attracted increasing attention because of their potential applications in bioimaging,diagnostics, and theranostics, for example, in vivo study of the delivery and the distribution of active substances. However, fluorescent vesicles containing conventional organic dyes often suffer from the problem of aggregation-caused quenching(ACQ) of fluorescence.Fluorescent vesicles working with aggregation-induced emission(AIE) offer an extraordinary tool to tackle the ACQ issue, showing advantages such as high emission efficiency, superior photophysical stability, low background interference, and high sensitivity. AIE fluorescent vesicles represent a new type of fluorescent and functional nanomaterials. In this review, we summarize the recent advances in the development of AIE fluorescent vesicles. The review is organized according to the chemical structures and architectures of the amphiphilic molecules that constitute the AIE vesicles, i.e., small-molecule amphiphiles, amphiphilic polymers, and amphiphilic supramolecules and supramacromolecules. The studies on the applications of these AIE vesicles as stimuli-responsive vesicles,fluorescence-guided drug release carriers, cell imaging tools, and fluorescent materials based on fluorescence resonance energy transfer(FRET) are also discussed.展开更多
Aiming at overcoming the strength-ductility trade-off in structural Ti-alloys,a new family of TRIP/TWIP Ti-alloys was developed in the past decade(TWIP:twinning-induced plasticity;TRIP:transformationinduced plasticity...Aiming at overcoming the strength-ductility trade-off in structural Ti-alloys,a new family of TRIP/TWIP Ti-alloys was developed in the past decade(TWIP:twinning-induced plasticity;TRIP:transformationinduced plasticity).Herein,we study the tunable nature of deformation mechanisms with various TWIP and TRIP contributions by fine adjustment of the Zr content on ternary Ti-12 Mo-xZr(x=3,6,10)alloys.The microstructure and deformation mechanisms of the Ti-Mo-Zr alloys are explored by using in-situ electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM).The results show that a transition of the dominant deformation mode occurred,going from TRIP to TWIP major mechanism with increasing Zr content.In the Ti-12 Mo-3 Zr alloy,the stress-induced martensitic transformation(SIM)is the major deformation mode which accommodates the plastic flow.Regarding the Ti-12 Mo-6 Zr alloy,the combined deformation twinning(DT)and SIM modes both contribute to the overall plasticity with enhanced strain-hardening rate and subsequent large uniform ductility.Further increase of the Zr content in Ti-12 Mo-10 Zr alloy leads to an improved yield stress involving single DT mode as a dominant deformation mechanism throughout the plastic regime.In the present work,a set of comprehensive in-situ and ex-situ microstructural investigations clarify the evolution of deformation microstructures during tensile loading and unloading processes.展开更多
The devitrification of glasses with composition 50GeO2-40PbO-10PbF2-xREF3, RE = Gd, Eu, 0 3+: β-PbF2 nanocrystals embedded in a glassy oxide matrix. This transformation is investigated using thermal analysis, X-ray d...The devitrification of glasses with composition 50GeO2-40PbO-10PbF2-xREF3, RE = Gd, Eu, 0 3+: β-PbF2 nanocrystals embedded in a glassy oxide matrix. This transformation is investigated using thermal analysis, X-ray diffraction and electron microscopy. A comparison with RE3+: β-PbF2 ceramics prepared by standard ceramic techniques is performed. The Rare Earth cations show a strong nucleating effect for the precipitation of the RE3++: β-PbF2 nanocrystals. The evolution of the unit cell parameters of the REF3: β-PbF2 solid solution results from a combined effect of Pb2+-RE3+ substitution and interstitial F– introduction. In the glass ceramics, RE3+: β-PbF2 nanocrystals are constrained by the glassy matrix when they form with a pressure equivalent to 1.6 GPa. The constrained nanocrystals can return to a relaxed state by chemical dissolution of the embedding glassy matrix, followed by thermal treatments.展开更多
Research into environmentally friendly strategies for hydrogen transfer reduction is increasing, along with the need for more elaborate heterocyclic platforms. Within this context, we develop a new approach for substi...Research into environmentally friendly strategies for hydrogen transfer reduction is increasing, along with the need for more elaborate heterocyclic platforms. Within this context, we develop a new approach for substituted dihydrobenzo[c]carbazoles and indoles. These compounds were synthesized through an iron-catalyzed hydrogen transfer reduction of nitroarenes, followed by intramolecular cyclization. This transformation involves using a Kn?lker-type catalyst, Cs_(2)CO_(3) as the base, and benzyl alcohol as the nonexpensive and low volatile hydrogen donor. We synthesize 30 examples of aza-heterocycles with moderate to excellent yields by applying this strategy. Additionally, DFT calculations demonstrated that the pathway reaction could follow an anionic mechanism.展开更多
Water-soluble thermoresponsive polymers present either upper critical solution temperature(UCST) or lower critical solution tempe rature(LCST) depending on the location of their miscibility range with water at high te...Water-soluble thermoresponsive polymers present either upper critical solution temperature(UCST) or lower critical solution tempe rature(LCST) depending on the location of their miscibility range with water at high temperatures or at low temperatures.Compared with LCST polymers,the water-soluble UCST polymers are still less explored until now.In this work three copolymers of P(AAm-co-GAA) were synthesized by copolymerizing two acrylamide monomers,acrylamide(AAm) and acrylamide functionalized with natural glycyrrhetinic acid(GAA),using reversible addition-fragmentation chain transfer(RAFT) polymerization.These copolymers exhibited the typical UCST thermoresponsive behavior,and their phase transition temperatures could be easily tuned to around 37℃ for potential biological applications.Moreover,the UCST of P(AAm-co-GAA) can be adjusted not only by the content of glycyrrhetinic acid(GA) and polymer concentrations,but also by the host-vip interactions between GA and cyclodextrins(β-and γ-CD).The suitable value of UCST and the biocompatible nature of GA and CDs may endow these copolymers with practical applications in biomedical chemistry.展开更多
During the last decades,a large amount of scientific works had been devoted toβ-type Zr and Ti alloys for biomedical applica-tions due to their high strength,good corrosion resistance,low magnetic susceptibility and ...During the last decades,a large amount of scientific works had been devoted toβ-type Zr and Ti alloys for biomedical applica-tions due to their high strength,good corrosion resistance,low magnetic susceptibility and superior biocompatibility[1].展开更多
This study proposes a novel strategy for the design of a new family of metastable Zr alloys.These al-loys offer improved mechanical properties for implants,particularly in applications where conventional stainless ste...This study proposes a novel strategy for the design of a new family of metastable Zr alloys.These al-loys offer improved mechanical properties for implants,particularly in applications where conventional stainless steels and Co-Cr alloys are currently used but lack suitability.The design approach is based on the controlled twinning-induced plasticity(TWIP)effect,significantly enhancing the ductility and strain-hardenability of the Zr alloys.In order to draw a“blueprint”for the compositional design of biomedical T WIP(Bio-T WIP)Zr alloys-using only non-toxic elements,the study combines D-electron phase stability calculations(specifically bond order(Bo)and mean d-orbital energy(Md))with a systematic experimental screening of active deformation mechanisms within the Zr-Nb-Sn alloy system.This research aids in ac-curately identifying the TWIP line,which signifies the mechanism shift between TWIP and classic slip as the primary deformation mechanism.To demonstrate the efficacy of the TWIP mechanism in enhancing mechanical properties,Zr-12Nb-2Sn,Zr-13Nb-1Sn,and Zr-14Nb-3Sn alloys are selected.Results indicate that the TWIP mechanism leads to a significant improvement of strain-hardening rate and a uniform elongation of∼20%in Zr-12Nb-2Sn,which displays both{332}<113>mechanical twinning and disloca-tion slip as the primary deformation mechanisms.Conversely,Zr-14Nb-3Sn exhibits the typical mechan-ical properties found in stable body-centered cubic(BCC)alloys,characterized by the sole occurrence of dislocation slip.Cell viability tests confirm the superior biocompatibility of Zr-Nb-based alloys with deformation twins on the surface,in line with existing literature.Based on the whole set of results,a comprehensive design diagram is proposed.展开更多
Thermal treatment either in the presence of oxygen (calcination) or of a reducing agent (reduction) result is all the time a key issue within the preparation of a catalyst. In this work, a microwave plasma treatment w...Thermal treatment either in the presence of oxygen (calcination) or of a reducing agent (reduction) result is all the time a key issue within the preparation of a catalyst. In this work, a microwave plasma treatment was chosen as an alternative to typical calcinations, because it is a more energy efficient process. Thus, a Microwave Fluidized Bed Plasma reactor (MFBP) was employed in catalyst synthesis process under different gas compositions, such as argon and argon/oxygen mixtures over g-alumina supported silver catalysts, which are generally used for selective reduction of NOx by ethanol. After the first catalytic tests performed in the presence of plasma treated catalyst, it can be concluded that plasma treatment process represents an interesting alternative to conventional calcination during catalyst synthesis, resulting in a more sustainable process, moreover in view of its industrial application. In order to understand the particular effect of plasma treatment, the catalysts submitted to this treatment were carefully characterized by means of thermo gravimetric analysis (TGA), differential thermal analysis (DTA) and UV-VIS-NIR.展开更多
Zinc oxide nanoparticles with different sizes and shapes have been synthesized in polyol using a bottom-up approach. We have studied the scale-up of the process to massively produce high quality nanoparticles of contr...Zinc oxide nanoparticles with different sizes and shapes have been synthesized in polyol using a bottom-up approach. We have studied the scale-up of the process to massively produce high quality nanoparticles of controlled size and shape. The scale-up strategy required the effective mixing of reagents using either axial or radial mixing configurations and was experimentally validated by comparing structural properties of particles obtained in a small and a large size reactor. In addition, the flow patterns in these reactors have been calculated using three-dimensional turbulent computational fluid dynamics (CFD) simulations. Our results indicate a strong connection between the flow patterns, as obtained by CFD simulations, and the size and shape of the particles. Actually, our pilot scale reactor allowed producing sample aliquots of ~50 grams with nanoparticle sizes ranging from 8 nm to 600 nm and aspect ratio varying from 1 (nanospheres) to 20 (nanorods). After their synthesis, these two nanoparticle classes have been tested as building blocks in D149-dye-sensitized solar cell (DSSC). The measured power conversion efficiency (PCE) was 4.66% for nanorods shaped particles and 4.21% for nanospheres. These values were significantly higher than the 3.90% PCE obtained with commercial Degussa VP20 ZnO nanoparticles.展开更多
Labor-intensive,trial-and-error methods are frequently employed for modifying the perovskite surface to mitigate trap defects.There is an urgent need for rationally designed and efficient molecular passivators.To addr...Labor-intensive,trial-and-error methods are frequently employed for modifying the perovskite surface to mitigate trap defects.There is an urgent need for rationally designed and efficient molecular passivators.To address the performance and stability challenges caused by defects in polycrystalline perovskite,we have rationally designed and tailored passivation molecules,4-(trifluoromethyl)benzoic anhydride(TFBA),ethyl 4-(trifluoromethyl)benzoate(TFB),and 4-(trifluoromethyl)benzoic acid(PTF),to minimize interfacial energy loss and modulate the bandgap alignment for achieving efficient perovskite solar cells(PSCs).These molecules could target the perovskite surface defects,particularly Pb-I antisite defects,with the-COOH and trifluoromethyl functional groups at the edges.Among them,PTF exhibited superior passivation performance by coordinat-ing its carboxyl group withPb2+,effectively suppressing non-radiative recombination.Additionally,the fluorine sites in these molecules corrected lattice distortions and stabilized the perovskite structure through hydrogen bonding with MA/FA cations,reducing ion migration,and enhancing moisture resistance.As a result,PTF-modified PSCs achieved an efficiency of 25.57%and maintained over 85%of their initial efficiency after 1600 h of aging.This study provides a clear pathway for optimizing passivation strategies through rational molecular design.展开更多
Light-matter interactions are frequently perceived as predominantly influenced by the electric field,with the magnetic component of light often overlooked.Nonetheless,the magnetic field plays a pivotal role in various...Light-matter interactions are frequently perceived as predominantly influenced by the electric field,with the magnetic component of light often overlooked.Nonetheless,the magnetic field plays a pivotal role in various optical processes,including chiral light-matter interactions,photon-avalanching,and forbidden photochemistry,underscoring the significance of manipulating magnetic processes in optical phenomena.Here,we explore the ability to control the magnetic light and matter interactions at the nanoscale.In particular,we demonstrate experimentally,using a plasmonic nanostructure,the transfer of energy from the magnetic nearfield to a nanoparticle,thanks to the subwavelength magnetic confinement allowed by our nano-antenna.This control is made possible by the particular design of our plasmonic nanostructure,which has been optimized to spatially decouple the electric and magnetic components of localized plasmonic fields.Furthermore,by studying the spontaneous emission from the Lanthanide-ions doped nanoparticle,we observe that the measured field distributions are not spatially correlated with the experimentally estimated electric and magnetic local densities of states of this antenna,in contradiction with what would be expected from reciprocity.We demonstrate that this counter-intuitive observation is,in fact,the result of the different optical paths followed by the excitation and emission of the ions,which forbids a direct application of the reciprocity theorem.展开更多
Optical memories can be categorized into three regimes,including the optical data storage that use light as a tool to store classical bit values[1,2],coherent memories for light which preserve the amplitude and the ph...Optical memories can be categorized into three regimes,including the optical data storage that use light as a tool to store classical bit values[1,2],coherent memories for light which preserve the amplitude and the phase information of input optical pulses[3,4]and optical quantum memories that specifically work for quantum light field[5,6].Recently,Bland-Hawthorn et al.[7]proposed to construct long-baseline optical telescopes based on transportable optical memories.展开更多
Trivalent lanthanides in wide bandgap fluoride or phosphate hosts can present persistent luminescence between 200 nm and 1.7 μm after charging by X-rays.Mechanisms are reviewed and applications envisioned.
Nature is providing inspiration for researchers to mimic its functions or existing structures,which could remarkably promote the development of new materials.Here,a large-size honeycomb-shaped liquid crystal elastomer...Nature is providing inspiration for researchers to mimic its functions or existing structures,which could remarkably promote the development of new materials.Here,a large-size honeycomb-shaped liquid crystal elastomer(LCE)actuator with LC orientation along the height of the honeycomb shape is built by combining magnetic field alignment and soft lithography technology.This homeotropic alignment allowed the height contraction of honeycomb and pore size expansion of hexagons in a reversible manner upon temperature variation.Therefore,this LCE actuator can be used as a structure for temperature-gated separation of particles.Another example is an iris-like LCE actuator,which has the capability of adjusting its aperture size with a temperature variation.Our approach provides a simple way to design customizable sophisticated LCE actuators for various potential applications.展开更多
Nanoporous membranes and vesicles are interesting systems with potential in applications offering channels for material exchange.Herein,nanoporous membranes and polymersomes are developed by self-assembly of trans-and...Nanoporous membranes and vesicles are interesting systems with potential in applications offering channels for material exchange.Herein,nanoporous membranes and polymersomes are developed by self-assembly of trans-and cis-stereoisomers of amphiphilic polymers.Two polymers,PEG550-TPEChol and PEG550-SS-TPE-SS-Chol,containing a central tetraphenylethene(TPE),a cholesterol(Chol),and a poly(ethylene glycol)(PEG550)are studied.展开更多
基金financially supported by the Beijing Natural Science Foundation(No.L233016)。
文摘Polyaniline(PANi)hydrogels have a wide range of applications in artificial skin,flexible robotics,and movement monitoring.Nevertheless,limited by the modulus mismatch between rigid PANi and the soft hydrogel matrix,the high strength and toughness of the PANi hydrogel are mutually exclusive.Although the introduction of sacrificial bonds into the hydrogel network can alleviate this contradiction to a certain extent,it always causes pronounced energy hysteresis during hydrogel deformation.Inspired by the energy storage and release of macroscopic springs,in this work,we propose a molecular entanglement approach for the fabrication of PANi hydrogels featuring high toughness and low hysteresis,where flexible poly(ethylene glycol)(PEG)is entangled with chemically cross-linked poly(acrylic acid)(PAA)as a hydrogel matrix,and rigid PANi as a conductive filler.The resultant PAA/PEG/PANi hydrogel exhibited high mechanical properties(fracture strength of 0.75 MPa and toughness of 4.81 MJ·m^(-3))and a low energy dissipation ratio(28.2%when stretching to 300%).Moreover,the PAA/PEG/PANi hydrogel possesses a good electrical response to external forces and can be employed as a strain sensor to monitor human joint movements by producing specific electrical signals.This work provides a straightforward strategy for preparing tough conductive PANi hydrogels with low hysteresis,showing potential for the development of healthcare devices.
基金Min Liu thanks the CSC for funding his PhD scholarship(grant number 202008120110)The ANR agency is acknowledged for financial support via the ChemSta project ANR-21-CE05-0022.
文摘Because of their better chemical stability and fascinating anisotropic characteristics,Dion-Jacobson(DJ)-layered halide perovskites,which owe crystallographic two-dimensional structures,have fascinated growing attention for solar devices.DJ-layered halide perovskites have special structural and photoelectronic features that allow the van der Waals gap to be eliminated or reduced.DJ-layered halide perovskites have improved photophysical characteristics,resulting in improved photovoltaic performance.Nevertheless,owing to the nature of the solution procedure and the fast crystal development of DJ perovskite thin layers,the precursor compositions and processing circumstances can cause a variety of defects to occur.The application of additives can impact DJ perovskite crystallization and film generation,trap passivation in the bulk and/or at the surface,interface structure,and energetic tuning.This study discusses recent developments in additive engineering for DJ multilayer halide perovskite film production.Several additive-assisted bulk and interface optimization methodologies are summarized.Lastly,an overview of research developments in additive engineering in the production of DJ-layered halide perovskite solar cells is offered.
基金the French National Research Agency(No.ANR16-CE29-0028)the National Natural Science Foundation of China(No.21674091)+2 种基金the Joint Foundation of Shaanxi Province Natural Science Basic Research ProgramShaanxi Coal Chemical Group Co.,Ltd.(No.2019JLM-46)for financial supportthe China Scholarship Council for funding his Ph.D.scholarship in France。
文摘Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-NTA)initiated by amino-terminated PEG.The self-assemblies of three PEG-b-PMeSPG copolymers with different PMeSPG block lengths were first prepared by nanoprecipitation method using THF and DMF,respectively,as the organic solvent,and their morphologies were studied by Cryo-EM and DLS.To prepare polymersomes loaded with glucose oxidase(GOx),double emulsion method followed by extrusion treatment was employed.The oxidation-responsive disruption of polymersomes was achieved upon the introduction of glucose because of the oxidants generated insitu by GOx/glucose.
基金supported by the National Natural Science Foundation of China (Grant Nos. 62004058, U21A2076, 21701041, 52071048)the Nature Science Foundation of Hebei Province (Grant No. F2020202022)+4 种基金the Open Fund of the State Key Laboratory of Integrated Optoelectronics (Grant No. IOSKL2020KF09)the State Key Laboratory of Reliability and Intelligence of Electrical Equipment (Grant No. EERI_PI20200005)supported by the Support plan for Overseas Students to Return to China for Entrepreneurship and Innovation (Grant No. cx2020003)the Fundamental Research Funds for the Central Universities (Grant No. 2020CDJ-LHZZ-074)the Natural Science Foundation of Chongqing (Grant No. cstc2020jcyjmsxmX0629)。
文摘Interfacial defects and energy barrier would result in serious interfacial non-radiative recombination losses.In addition,the quality of perovskite films is highly dependent on deposition substrates.Consequently,there is an urgent desire to develop multifunctional interface modulators to manage the interface between electron transport layer and perovskite layer.Here,we report a multifunctional buried interface modulation strategy that 4-fluoro-phenylammonium tetrafluoroborate (FBABF_(4)) consisting of simultaneously fluorinated anion and cation is inserted between SnO_(2)layer and perovskite layer.It is uncovered by time-of-flight secondary ion mass spectroscopy that the anion and cation in modifier are mainly located at this interface,which is put down to coordination bond of the fluorine atom on BF_(4)^(-) with SnO_(2),and the hydrogen bond of the fluorine atom on FBA^(+) with formamidinium.This suggests that simultaneous fluorination of anion and cation in the ionic liquid molecule is of crucial importance to ameliorate interfacial contact through chemical linker.The interface modification approach enables the realization of interfacial defect passivation,interfacial energy band alignment modulation,and perovskite crystallization manipulation,which are translated into enhanced efficiency and stability as well as significantly suppressed hysteresis.The multiple functions of FBABF_(4) endow the modified solar cells excellent photovoltaic performance with an efficiency exceeding 23%along with appealing long-term stability.This work highlights the critical role of fluorination strategy in engineering multifunctional organic salt modulators for improving interfacial contact.
基金financially supported by the French National Research Agency (No. ANR-16-CE29-0028)the National Natural Science Foundation of China (Nos. 21604001 and 21528402)
文摘Fluorescent vesicles have recently attracted increasing attention because of their potential applications in bioimaging,diagnostics, and theranostics, for example, in vivo study of the delivery and the distribution of active substances. However, fluorescent vesicles containing conventional organic dyes often suffer from the problem of aggregation-caused quenching(ACQ) of fluorescence.Fluorescent vesicles working with aggregation-induced emission(AIE) offer an extraordinary tool to tackle the ACQ issue, showing advantages such as high emission efficiency, superior photophysical stability, low background interference, and high sensitivity. AIE fluorescent vesicles represent a new type of fluorescent and functional nanomaterials. In this review, we summarize the recent advances in the development of AIE fluorescent vesicles. The review is organized according to the chemical structures and architectures of the amphiphilic molecules that constitute the AIE vesicles, i.e., small-molecule amphiphiles, amphiphilic polymers, and amphiphilic supramolecules and supramacromolecules. The studies on the applications of these AIE vesicles as stimuli-responsive vesicles,fluorescence-guided drug release carriers, cell imaging tools, and fluorescent materials based on fluorescence resonance energy transfer(FRET) are also discussed.
基金supported by National Natural Science foundation of China(Grant No.51601216 and 51901193)China Postdoctoral Science Foundation(Grant No.2018M632414)+4 种基金Fund of State Key Lab of Advanced Metals and Materials,University of Science and Technology Beijing(Grant No.2019-ZD03)Fundamental Research Funds for the Central Universities(Grant No.2017XKQY009)Funds of Industry-University-Research Cooperation in Jiangsu Province(Grand No.BY2018075)Key Research and Development Program of Shaanxi(Grant No.2019GY-151)sponsored by China Scholarship Council。
文摘Aiming at overcoming the strength-ductility trade-off in structural Ti-alloys,a new family of TRIP/TWIP Ti-alloys was developed in the past decade(TWIP:twinning-induced plasticity;TRIP:transformationinduced plasticity).Herein,we study the tunable nature of deformation mechanisms with various TWIP and TRIP contributions by fine adjustment of the Zr content on ternary Ti-12 Mo-xZr(x=3,6,10)alloys.The microstructure and deformation mechanisms of the Ti-Mo-Zr alloys are explored by using in-situ electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM).The results show that a transition of the dominant deformation mode occurred,going from TRIP to TWIP major mechanism with increasing Zr content.In the Ti-12 Mo-3 Zr alloy,the stress-induced martensitic transformation(SIM)is the major deformation mode which accommodates the plastic flow.Regarding the Ti-12 Mo-6 Zr alloy,the combined deformation twinning(DT)and SIM modes both contribute to the overall plasticity with enhanced strain-hardening rate and subsequent large uniform ductility.Further increase of the Zr content in Ti-12 Mo-10 Zr alloy leads to an improved yield stress involving single DT mode as a dominant deformation mechanism throughout the plastic regime.In the present work,a set of comprehensive in-situ and ex-situ microstructural investigations clarify the evolution of deformation microstructures during tensile loading and unloading processes.
文摘The devitrification of glasses with composition 50GeO2-40PbO-10PbF2-xREF3, RE = Gd, Eu, 0 3+: β-PbF2 nanocrystals embedded in a glassy oxide matrix. This transformation is investigated using thermal analysis, X-ray diffraction and electron microscopy. A comparison with RE3+: β-PbF2 ceramics prepared by standard ceramic techniques is performed. The Rare Earth cations show a strong nucleating effect for the precipitation of the RE3++: β-PbF2 nanocrystals. The evolution of the unit cell parameters of the REF3: β-PbF2 solid solution results from a combined effect of Pb2+-RE3+ substitution and interstitial F– introduction. In the glass ceramics, RE3+: β-PbF2 nanocrystals are constrained by the glassy matrix when they form with a pressure equivalent to 1.6 GPa. The constrained nanocrystals can return to a relaxed state by chemical dissolution of the embedding glassy matrix, followed by thermal treatments.
文摘Research into environmentally friendly strategies for hydrogen transfer reduction is increasing, along with the need for more elaborate heterocyclic platforms. Within this context, we develop a new approach for substituted dihydrobenzo[c]carbazoles and indoles. These compounds were synthesized through an iron-catalyzed hydrogen transfer reduction of nitroarenes, followed by intramolecular cyclization. This transformation involves using a Kn?lker-type catalyst, Cs_(2)CO_(3) as the base, and benzyl alcohol as the nonexpensive and low volatile hydrogen donor. We synthesize 30 examples of aza-heterocycles with moderate to excellent yields by applying this strategy. Additionally, DFT calculations demonstrated that the pathway reaction could follow an anionic mechanism.
基金supported by National Key R&D Program of China(No.2017YFD0200302)the National Natural Science Foundation of China(NSFC,No.2604085)。
文摘Water-soluble thermoresponsive polymers present either upper critical solution temperature(UCST) or lower critical solution tempe rature(LCST) depending on the location of their miscibility range with water at high temperatures or at low temperatures.Compared with LCST polymers,the water-soluble UCST polymers are still less explored until now.In this work three copolymers of P(AAm-co-GAA) were synthesized by copolymerizing two acrylamide monomers,acrylamide(AAm) and acrylamide functionalized with natural glycyrrhetinic acid(GAA),using reversible addition-fragmentation chain transfer(RAFT) polymerization.These copolymers exhibited the typical UCST thermoresponsive behavior,and their phase transition temperatures could be easily tuned to around 37℃ for potential biological applications.Moreover,the UCST of P(AAm-co-GAA) can be adjusted not only by the content of glycyrrhetinic acid(GA) and polymer concentrations,but also by the host-vip interactions between GA and cyclodextrins(β-and γ-CD).The suitable value of UCST and the biocompatible nature of GA and CDs may endow these copolymers with practical applications in biomedical chemistry.
基金Junhui Tang is sponsored by China Scholarship Council。
文摘During the last decades,a large amount of scientific works had been devoted toβ-type Zr and Ti alloys for biomedical applica-tions due to their high strength,good corrosion resistance,low magnetic susceptibility and superior biocompatibility[1].
基金the support of the French Agence Nationale de la Recherche(ANR),under grant ANR-21-CE08-0022(project ISANAMI)Junhui TANG is sponsored by the China Scholarship Council.
文摘This study proposes a novel strategy for the design of a new family of metastable Zr alloys.These al-loys offer improved mechanical properties for implants,particularly in applications where conventional stainless steels and Co-Cr alloys are currently used but lack suitability.The design approach is based on the controlled twinning-induced plasticity(TWIP)effect,significantly enhancing the ductility and strain-hardenability of the Zr alloys.In order to draw a“blueprint”for the compositional design of biomedical T WIP(Bio-T WIP)Zr alloys-using only non-toxic elements,the study combines D-electron phase stability calculations(specifically bond order(Bo)and mean d-orbital energy(Md))with a systematic experimental screening of active deformation mechanisms within the Zr-Nb-Sn alloy system.This research aids in ac-curately identifying the TWIP line,which signifies the mechanism shift between TWIP and classic slip as the primary deformation mechanism.To demonstrate the efficacy of the TWIP mechanism in enhancing mechanical properties,Zr-12Nb-2Sn,Zr-13Nb-1Sn,and Zr-14Nb-3Sn alloys are selected.Results indicate that the TWIP mechanism leads to a significant improvement of strain-hardening rate and a uniform elongation of∼20%in Zr-12Nb-2Sn,which displays both{332}<113>mechanical twinning and disloca-tion slip as the primary deformation mechanisms.Conversely,Zr-14Nb-3Sn exhibits the typical mechan-ical properties found in stable body-centered cubic(BCC)alloys,characterized by the sole occurrence of dislocation slip.Cell viability tests confirm the superior biocompatibility of Zr-Nb-based alloys with deformation twins on the surface,in line with existing literature.Based on the whole set of results,a comprehensive design diagram is proposed.
文摘Thermal treatment either in the presence of oxygen (calcination) or of a reducing agent (reduction) result is all the time a key issue within the preparation of a catalyst. In this work, a microwave plasma treatment was chosen as an alternative to typical calcinations, because it is a more energy efficient process. Thus, a Microwave Fluidized Bed Plasma reactor (MFBP) was employed in catalyst synthesis process under different gas compositions, such as argon and argon/oxygen mixtures over g-alumina supported silver catalysts, which are generally used for selective reduction of NOx by ethanol. After the first catalytic tests performed in the presence of plasma treated catalyst, it can be concluded that plasma treatment process represents an interesting alternative to conventional calcination during catalyst synthesis, resulting in a more sustainable process, moreover in view of its industrial application. In order to understand the particular effect of plasma treatment, the catalysts submitted to this treatment were carefully characterized by means of thermo gravimetric analysis (TGA), differential thermal analysis (DTA) and UV-VIS-NIR.
文摘Zinc oxide nanoparticles with different sizes and shapes have been synthesized in polyol using a bottom-up approach. We have studied the scale-up of the process to massively produce high quality nanoparticles of controlled size and shape. The scale-up strategy required the effective mixing of reagents using either axial or radial mixing configurations and was experimentally validated by comparing structural properties of particles obtained in a small and a large size reactor. In addition, the flow patterns in these reactors have been calculated using three-dimensional turbulent computational fluid dynamics (CFD) simulations. Our results indicate a strong connection between the flow patterns, as obtained by CFD simulations, and the size and shape of the particles. Actually, our pilot scale reactor allowed producing sample aliquots of ~50 grams with nanoparticle sizes ranging from 8 nm to 600 nm and aspect ratio varying from 1 (nanospheres) to 20 (nanorods). After their synthesis, these two nanoparticle classes have been tested as building blocks in D149-dye-sensitized solar cell (DSSC). The measured power conversion efficiency (PCE) was 4.66% for nanorods shaped particles and 4.21% for nanospheres. These values were significantly higher than the 3.90% PCE obtained with commercial Degussa VP20 ZnO nanoparticles.
基金supported by the National Natural Science Foundation of China(U21A2076,62274018,52462031)The S&T Program of Hebei(24464401D)+3 种基金The Central Guidance on Local Science and Technology Development Fund of Hebei Province(226Z4305G)Hebei Province Higher Education Science and Technology Research Project(JZX2024030)Shijiazhuang Basic Research Project at Hebei-based Universities(241790847A)The Natural Science Foundation of Hebei Province(E2024202086,E2024202300).
文摘Labor-intensive,trial-and-error methods are frequently employed for modifying the perovskite surface to mitigate trap defects.There is an urgent need for rationally designed and efficient molecular passivators.To address the performance and stability challenges caused by defects in polycrystalline perovskite,we have rationally designed and tailored passivation molecules,4-(trifluoromethyl)benzoic anhydride(TFBA),ethyl 4-(trifluoromethyl)benzoate(TFB),and 4-(trifluoromethyl)benzoic acid(PTF),to minimize interfacial energy loss and modulate the bandgap alignment for achieving efficient perovskite solar cells(PSCs).These molecules could target the perovskite surface defects,particularly Pb-I antisite defects,with the-COOH and trifluoromethyl functional groups at the edges.Among them,PTF exhibited superior passivation performance by coordinat-ing its carboxyl group withPb2+,effectively suppressing non-radiative recombination.Additionally,the fluorine sites in these molecules corrected lattice distortions and stabilized the perovskite structure through hydrogen bonding with MA/FA cations,reducing ion migration,and enhancing moisture resistance.As a result,PTF-modified PSCs achieved an efficiency of 25.57%and maintained over 85%of their initial efficiency after 1600 h of aging.This study provides a clear pathway for optimizing passivation strategies through rational molecular design.
基金supported by the ERC grant FemtoMagnet(grant no.101087709)the financial support from the Agence Nationale de la Recherche(ANR-20-CE09-0031-01,ANR-22-CE09-0027-04 and ANR-23-ERCC-0005)the Institut de Physique du CNRS(Tremplin@INP 2020).
文摘Light-matter interactions are frequently perceived as predominantly influenced by the electric field,with the magnetic component of light often overlooked.Nonetheless,the magnetic field plays a pivotal role in various optical processes,including chiral light-matter interactions,photon-avalanching,and forbidden photochemistry,underscoring the significance of manipulating magnetic processes in optical phenomena.Here,we explore the ability to control the magnetic light and matter interactions at the nanoscale.In particular,we demonstrate experimentally,using a plasmonic nanostructure,the transfer of energy from the magnetic nearfield to a nanoparticle,thanks to the subwavelength magnetic confinement allowed by our nano-antenna.This control is made possible by the particular design of our plasmonic nanostructure,which has been optimized to spatially decouple the electric and magnetic components of localized plasmonic fields.Furthermore,by studying the spontaneous emission from the Lanthanide-ions doped nanoparticle,we observe that the measured field distributions are not spatially correlated with the experimentally estimated electric and magnetic local densities of states of this antenna,in contradiction with what would be expected from reciprocity.We demonstrate that this counter-intuitive observation is,in fact,the result of the different optical paths followed by the excitation and emission of the ions,which forbids a direct application of the reciprocity theorem.
基金supported by the National Key R&D Program of China (2017YFA0304100)Innovation Program for Quantum Science and Technology (2021ZD0301200)+2 种基金the National Natural Science Foundation of China (12222411 and 11821404)partially carried out at the USTC Center for Micro and Nanoscale Research and Fabricationthe support from the Youth Innovation Promotion Association CAS。
文摘Optical memories can be categorized into three regimes,including the optical data storage that use light as a tool to store classical bit values[1,2],coherent memories for light which preserve the amplitude and the phase information of input optical pulses[3,4]and optical quantum memories that specifically work for quantum light field[5,6].Recently,Bland-Hawthorn et al.[7]proposed to construct long-baseline optical telescopes based on transportable optical memories.
文摘Trivalent lanthanides in wide bandgap fluoride or phosphate hosts can present persistent luminescence between 200 nm and 1.7 μm after charging by X-rays.Mechanisms are reviewed and applications envisioned.
基金This study received support from the French National Research Agency(ANR-16-CE29-0028)from the“Institut Pierre-Gilles de Gennes”(IPGG,laboratoire d’excellence,“Investissements d’avenir”programs ANR-10-IDEX-0001-02 PSL,ANR10-LABX-31 and ANR10-EQPX-34).
文摘Nature is providing inspiration for researchers to mimic its functions or existing structures,which could remarkably promote the development of new materials.Here,a large-size honeycomb-shaped liquid crystal elastomer(LCE)actuator with LC orientation along the height of the honeycomb shape is built by combining magnetic field alignment and soft lithography technology.This homeotropic alignment allowed the height contraction of honeycomb and pore size expansion of hexagons in a reversible manner upon temperature variation.Therefore,this LCE actuator can be used as a structure for temperature-gated separation of particles.Another example is an iris-like LCE actuator,which has the capability of adjusting its aperture size with a temperature variation.Our approach provides a simple way to design customizable sophisticated LCE actuators for various potential applications.
基金support from the Centre National de la Recherche Scientifique(CNRS)through the Mission for Transversal and Interdisciplinary Initiatives(MITI)interdisciplinary programsthe French National Research Agency(ANR-16-CE29-0028)as well as National Natural Science Foundation of China(NSFC)(grant no.11674217)and Shanghai Municipal Science&Technology Major Project(grant no.2019SHZDZX01).
文摘Nanoporous membranes and vesicles are interesting systems with potential in applications offering channels for material exchange.Herein,nanoporous membranes and polymersomes are developed by self-assembly of trans-and cis-stereoisomers of amphiphilic polymers.Two polymers,PEG550-TPEChol and PEG550-SS-TPE-SS-Chol,containing a central tetraphenylethene(TPE),a cholesterol(Chol),and a poly(ethylene glycol)(PEG550)are studied.
