X-ray detectors show potential applications in medical imaging,materials science,and nuclear energy.To achieve high detection efficiency and spatial resolution,many conventional semiconductor materials,such as amorpho...X-ray detectors show potential applications in medical imaging,materials science,and nuclear energy.To achieve high detection efficiency and spatial resolution,many conventional semiconductor materials,such as amorphous selenium,cadmium telluride zinc,and perovskites,have been utilized in direct conversion X-ray detectors.However,these semiconductor materials are susceptible to temperature-induced performance degradation,crystallization,delamination,uneven lattice growth,radiation damage,and high dark current.This study explores a new approach by coupling an FC40 electronic fluorinated liquid with a specialized high-resolution and high-readout-speed complementary metal-oxide-semiconductor(CMOS)pixel array,specifically the Topmetal II−chip,to fabricate a direct conversion X-ray detector.The fluorinated liquid FC40(molecular formula:C_(21)F_(48)N_(2))is an electronic medium that is minimally affected by temperature and displays no issues with uniform conductivity.It exhibits a low dark current and minimal radiation damage and enables customizable thickness in X-ray absorption.This addresses the limitations inherent in conventional semiconductor-based detectors.In this study,simple X-ray detector imaging tests were conducted,demonstrating the excellent coupling capability between FC40 electronic fluorinated liquid and CMOS chips by the X-ray detector.A spatial resolution of 4.0 lp/mm was measured using a striped line par card,and a relatively clear image of a cockroach was displayed in the digital radiography imaging results.Preliminary test results indicated the feasibility of fabricating an X-ray detector by combining FC40 electronic fluorinated liquid and CMOS chips.Owing to the absence of issues related to chip-material coupling,a high spatial resolution could be achieved by reducing the chip pixel size.This method presents a new avenue for studies on novel liquid-based direct conversion X-ray detectors.展开更多
It is urgent to develop high-performance polyimide(PI)films that simultaneously exhibit high transparency,exceptional thermal stability,mechanical robustness,and low dielectric to fulfil the requirements of flexible d...It is urgent to develop high-performance polyimide(PI)films that simultaneously exhibit high transparency,exceptional thermal stability,mechanical robustness,and low dielectric to fulfil the requirements of flexible display technologies.Herein,a series of fluorinated polyimide films(FPIs)were fabricated by the condensation of 5,5′-(perfluoropropane-2,2-diyl)bis(isobenzofuran-1,3-dione)(6FDA)and the fluorinated triphenylmethane diamine monomer(EDA,MEDA and DMEDA)with heat-crosslinkable tetrafluorostyrene side groups,which was incorporated by different numbers of methyl groups pendant in the ortho position of amino groups.Subsequently,the FPI films underwent heating to produce crosslinking FPIs(C-FPIs)through the self-crosslinking of double bonds in the tetrafluorostyrene.The transparency,solvent resistance,thermal stability,mechanical robustness and dielectric properties of FPI and C-FPI films can be tuned by the number of methyl groups and crosslinking,which were deeply investigated by virtue of molecular dynamics(MD)simulations and density functional theory(DFT).As a result,all the films exhibited exceptional optically colorless and transparent,with transmittance in the visible region of 450-700 nm exceeding 79.9%,and the cut-off wavelengths(λ_(off))were nearly 350 nm.The thermal decomposition temperatures at 5% weight loss(T_(d5%))for all samples exceeded 504℃.These films exhibited a wide range of tunable tensile strength(46.5-75.1 MPa).Significantly,they showed exceptional dielectric properties with the dielectric constant of 2.3-2.5 at full frequency(10^(7)-20 Hz).This study not only highlights the relationship between the polymer molecular structure and properties,but offer insights for balancing optical transparency,heat resistance and low dielectric constant in PI films.展开更多
The construction of monodisperse microporous organic microspheres is deemed a challenging issue,primarily due to the difficulty in achieving both high microporosity and uniformity within the microspheres.In this study...The construction of monodisperse microporous organic microspheres is deemed a challenging issue,primarily due to the difficulty in achieving both high microporosity and uniformity within the microspheres.In this study,a series of fluorinated monodisperse microporous microspheres are fabricated by solvothermal precipitation polymerization.The resulting fluorous methacrylate-based microspheres achieved higher than 400 m^(2)/g surface area,along with a yield of over 90%for the microspheres.Through comprehensive characterization and simulation methods,we discovered that the introduction of fluorous methacrylate monomers at high loading levels is the key factor contributing to the formation of the microporosity within the microspheres.The controlled temperature profile was found to be advantageous for achieving a high yield of microspheres and increased uniformity.Two-dimensional assemblies of these fluorinated microsphere arrays exhibited superhydrophobicity,superolephilicity,and water sliding angles below 10°.Furthermore,a three-dimensional assembly of the fluorinated microporous microsphere in a chromatographic column demonstrated significant improvement in the separation of Engelhardt agent compared to commercial columns.Our work offers a novel approach to constructing fluorinated monodisperse microporous microspheres for advanced applications.展开更多
Fluorinated gases(F-gases)play a vital role in the chemical industry and in the fields of air conditioning,refrigeration,health care,and organic synthesis.However,the direct emission of waste gases containing F-gases ...Fluorinated gases(F-gases)play a vital role in the chemical industry and in the fields of air conditioning,refrigeration,health care,and organic synthesis.However,the direct emission of waste gases containing F-gases into the atmosphere contributes to greenhouse effects and generates toxic substances.Developing porous materials for the energy-efficient capture,separation,and recovery of F-gases is highly desired.Recently,as a highly designable porous adsorbents,metal–organic frameworks(MOFs)exhibit excellent selective sorption performance toward F-gases,especially for the recognition and separation of different F-gases with highly similar properties,showing their great potential in F-gases control and recovery.In this review,we discuss the capture and separation of F-gases and their azeotropic,near-azeotropic,and isomeric mixtures in various application scenarios by MOFs,specifically classify and analyze molecular interaction between F-gases and MOFs,and interpret the mechanisms underlying their high performance regarding both adsorption capacity and selectivity,providing a repertoire for future materials design.Challenges faced in the transformation research roadmap of MOFs adsorbent separation technologies toward F-gases are also discussed,and areas for future research endeavors are highlighted.展开更多
In the research and production of fluorinated materials,large volumes of unstructured textual data are generated,characterized by high heterogeneity and fragmentation.These issues hinder systematic knowledge integrati...In the research and production of fluorinated materials,large volumes of unstructured textual data are generated,characterized by high heterogeneity and fragmentation.These issues hinder systematic knowledge integration and efficient utilization.Constructing a knowledge graph for fluorinated materials processing is essential for enabling structured knowledge management and intelligent applications.Among its core components,Named Entity Recognition(NER)plays an essential role,as its accuracy directly impacts relation extraction and semantic modeling,which ultimately affects the knowledge graph construction for fluorinated materials.However,NER in this domain faces challenges such as fuzzy entity boundaries,inconsistent terminology,and a lack of high-quality annotated corpora.To address these problems,(i)We first construct a domain-specific NER dataset by combining manual annotation with an improved Easy Data Augmentation(EDA)strategy;(ii)Secondly,we propose a novel model,RRC-ADV,which integrates RoBERTa-wwm for dynamic contextual word representation,adversarial training to improve robustness against boundary ambiguity,and a Residual BiLSTM(ResBiLSTM)to enhance sequential feature modeling.Further,a Conditional Random Field(CRF)layer is incorporated for globally optimized label prediction.Experimental results demonstrate that RRC-ADV achieves an average F1 score of 89.23%on the self-constructed dataset,significantly outperforming baseline models.The model exhibits strong robustness and adaptability within the domain of fluorinated materials.Our work enhances the accuracy of NER in the fluorinated materials processing domain and paves the way for downstream tasks such as relation extraction in knowledge graph construction.展开更多
Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene...Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene-co-p-terphenyl piperidinium)(PPTP3F_(x)-DIL)AEMs with different fluorinated monomers for high performance AEMFCs.The polymerization of fluorinated monomers with other aryl monomers can effectively promote the separation of microphase in the membrane.It also has a high OH-conductivity at a low swelling.The membrane(PPTP3F_(4)-DIL)prepared by polycondensation of 2,2,2-trifluoro-1-(p-tolyl)ethan 1-one monomer achieves a high conductivity of 168.5 mS cm^(-1)at 80℃.At the same time,the water uptake is 40.0%and the swelling ratio is 12.1%.In addition,these membranes also have good mechanical properties and alkaline stability.After 1440 h of treatment in a NaOH(2 M)solution at 80℃,PPTP3F_(x)-DIL still maintains excellent tensile strength(>30.3 MPa)and elongation at break(>43.4%),and the conductivity retention of the PPTP3F_(1)-DIL membrane is 90.3%.The PPTP3F_(4)-DIL-based single cell exhibits a high peak power density(918.1 mW cm^(-2))and excellent durability(100 h)at 80℃.Therefore,these PPTP3F_(x)-DIL membranes have a wide range of applications in AEMFCs.展开更多
The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely investigated.However,the question of ...The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely investigated.However,the question of the“trade-off”between AEM ionic conductivity and dimensional stability remains difficult.The strategy of inducing microphase separation to improve the performance of AEM has attracted much attention recently,but the design of optimal molecular structures is still being explored.Here,this work introduced different ratios of 3-bromo-1,1,1-trifluoroacetone(x=40,50,and 60)into the main chain of poly(p-terphenylene isatin).Because fluorinated groups have excellent hydrophobicity,hydrophilic hydroxyl-containing side chains are introduced to jointly adjust the formation of phase separation structure.The results show that PTI-PTF_(50)-NOH AEM with the appropriate fluorinated group ratio has the best ionic conductivity and alkali stability under the combined effect of both.It has an ionic conductivity of 133.83 mS cm^(-1)at 80°C.In addition,the OH-conductivity remains at 89%of the initial value at 80°C and 3 M KOH for 1056 h of immersion.The cell polarization curve based on PTI-PTF_(50)-NOH shows a power density of 734.76 mW cm^(-2)at a current density of 1807.7 mA cm^(-2).展开更多
Fluorinated fused azobenzene boron(FBAz)is a novel electron-deficient building block for polymer electron acceptors in all-polymer solar cells(all-PSC).The B←N bridging units impart a fixed configuration and low-lyin...Fluorinated fused azobenzene boron(FBAz)is a novel electron-deficient building block for polymer electron acceptors in all-polymer solar cells(all-PSC).The B←N bridging units impart a fixed configuration and low-lying LUMO/HOMO energy.Three polymer acceptor materials(P2f,P3f and P5f)with different fluorine substitution positions by copolymerizing FBAz with indacenodithiophene(IDT),are synthesized and investigated to study the influence of fluorinated forms on the all-polymer solar cell performance.The FBAz units are synthesized in just three steps,facilitating the straightforward production of polymer acceptors P2f,P3f,and P5f.These acceptors exhibit strong light absorption in the visible to near-infrared range of 500-1000nm and possess suitable LUMO/HOMO energy levels of-3.99/-5.66 eV which are very complementary to that(E_(LUMO/HOMO)=-3.59/-5.20 eV)of the widely-used polymer donor poly[(ethylhexylthiophenyl)-benzodithiophene-(ethylhexyl)-thienothiophene](PTB7-Th).All-polymer solar cells(all-PSCs)with PTB7-Th as electron donor and P3f as electron acceptor exhibits highest power conversion efficiencies(PCE)2.70%.When PC_(61)BM is added as the third component,the device efficiency can reach 5.36%.These preliminary results indicate that FBAz is a promising strong electron acceptor for the development of n-type polymer semiconductors,especially in organic photovoltaics(OPVs).To the best of our knowledge,this is the first example demonstrating the unique photovoltaic properties of the N=N double bond as an acceptor material.展开更多
To improve the friction and wear performance at room and elevated temperatures,Ti48Al2Nb2Cr(at.%)alloy was anodically fluorinated in an NH_(4)F-containing electrolyte.The effects of anodic fluorination on the friction...To improve the friction and wear performance at room and elevated temperatures,Ti48Al2Nb2Cr(at.%)alloy was anodically fluorinated in an NH_(4)F-containing electrolyte.The effects of anodic fluorination on the friction coefficient,wear rate,wear track morphology,and adhesion strength between the oxide scale and substrate were investigated.Results showed that the in-situ formation of Al_(2)O_(3)-enriched oxide scale was promoted due to fluorine effect,by which the surface hardness and wear resistance were both enhanced.After the friction and wear test,no noticeable changes were found on the fluorinated Ti48Al2Nb2Cr,whilst severe abrasion was evident on the GCr15 counterpart.This indicates that anodic fluorination could effectively enhance the friction and wear performance of Ti48Al2Nb2Cr alloy.At elevated temperatures,the dominant wear mechanism of the fluorinated Ti48Al2Nb2Cr/GCr15 pair was oxidation wear and adhesive wear.展开更多
Although the parallel incorporation of fluorinated aromatic amino acids(FAAAs)into proteins has been explored since 2010,the corresponding ^(19)F NMR investigation has been lacking to date.To assess the potential of t...Although the parallel incorporation of fluorinated aromatic amino acids(FAAAs)into proteins has been explored since 2010,the corresponding ^(19)F NMR investigation has been lacking to date.To assess the potential of the parallel incorporation of FAAAs in studies of protein structure,dynamics and interactions,we examine the protein yields,fluorine incorporation efficiencies,and ^(19)F NMR spectra upon simultaneously incorporating FAAAs including 3-fluorotyrosine(3FY),4-fluorophenylalanine(4FF)and 5-fluorotryptophan(5FW)into two model proteins:the structured protein GB1 domain(GB1)and the intrinsically disordered protein a-synuclein(a-syn).We found that the simultaneous incorporation of 3FY and 5FW achieved higher efficiency than combinations of 4FF and 5FW,4FF and 3FY,or 3FY,4FF and 5FW.Moreover,incorporating more types of FAAAs leads to a reduction in overall yield.The ^(19)F spectra of 3FY,4FF and 5FW residues in α-syn and GB1 exhibited good dispersion of chemical shifts.However,the GB1 spectrum showed complexity due to incomplete fluorination and interactions within aromatic cluster.This complexity could be significantly reduced by supplementing the medium with natural aromatic amino acids.To validate the advantage of ^(19)F NMR spectrum,we use 3FY-4FF-5FW-F94W-α-syn to investigate the interaction between α-syn and sodium dodecyl sulphate(SDS)micelle.Our study demonstrates that ^(19)F NMR spectroscopy of proteins with parallel incorporation of FAAAs provides a valuable tool for investigating protein conformation,dynamics and interactions.展开更多
A novel fluorinated polyurethane （FPU） with fluorine-containing pendent groups was prepared by using fluorinated polyether glycol （PTMG-g-HFP） as a soft segment, 1,6-hexamethylene diisocyanate （HDI） or toluene d...A novel fluorinated polyurethane （FPU） with fluorine-containing pendent groups was prepared by using fluorinated polyether glycol （PTMG-g-HFP） as a soft segment, 1,6-hexamethylene diisocyanate （HDI） or toluene diisocyanate （TD1） as a hard segment and 1,4-butanodiol （BDO） as a chain extender. FTIR, ^1H NMR, ^13C NMR and GPC were used to characterize the structure of the fluorinated polyurethane. Thermal stabilities of the fluorinated polyurethane and the corresponding hydrogenated polyurethane were studied by TGA. XPS analysis at two different sampling depths for the fluorinated polyurethane was used to investigate the surface compositions of FPU. The results showed the fluorine enrichment on the surface of FPU.展开更多
Ethyl-(2,2,2-trifluoroethyl)carbonate(ETFEC)is investigated as a solvent component in high-voltage electrolytes for LiNi0.5Mn1.5O4(LNMO).Our results show that the self-discharge behavior and the high temperature cycle...Ethyl-(2,2,2-trifluoroethyl)carbonate(ETFEC)is investigated as a solvent component in high-voltage electrolytes for LiNi0.5Mn1.5O4(LNMO).Our results show that the self-discharge behavior and the high temperature cycle performance can be significantly improved by the addition of 10%ETFEC into the normal carbonate electrolytes,e.g.,the capacity retention improved from 65.3%to 77.1%after 200 cycles at 60℃.The main reason can be ascribed to the high stability of ETFEC which prevents large oxidation of the electrolyte on the cathode surface.In addition,we also explore the feasibility of electrolytes using single fluoriated-solvents with and without additives.Our results show that the cycle performance of LNMO material can be greatly improved in 1 MLiPF6+pure ETFEC-solvent system with 2 wt%ethylene carbonate(EC)or ethylene sulfate(DTD).The capacity retention of the LNMO materials is 93%after 300 cycles,even better than that of carbonate-based electrolytes.It is shown that the additives are oxidized on the surface of LNMO particles and contribute to the formation of cathode/electrolyte interphase(CEI)films.This composite CEI film plays a crucial role in suppressing the serious decomposition of the electrolyte at high voltage.展开更多
This paper reported the oxidation of ethylbenzene catalyzed by fluorinated metalloporphyrins under mild conditions without any additives. The results showed that the cobalt(II)(5,10,15,20-tetrakis(pentafluorophenyl))p...This paper reported the oxidation of ethylbenzene catalyzed by fluorinated metalloporphyrins under mild conditions without any additives. The results showed that the cobalt(II)(5,10,15,20-tetrakis(pentafluorophenyl))porphyrin was the best catalyst among the fluorinated metalloporphyrins. The conversion of ethylbenzene reached 38.6%, the selectivity to acetophenone reached 94.0%, and the turnover number is 2719 under the optimal conditions.展开更多
Lithium–sulfur(Li–S) batteries represent a "beyond Li-ion" technology with low cost and high theoretical energy density and should fulfill the ever-growing requirements of electric vehicles and stationary ...Lithium–sulfur(Li–S) batteries represent a "beyond Li-ion" technology with low cost and high theoretical energy density and should fulfill the ever-growing requirements of electric vehicles and stationary energy storage systems. However, the sulfur-based conversion reaction in conventional liquid electrolytes results in issues like the so-called shuttle effect of polysulfides and lithium dendrite growth, which deteriorate the electrochemical performance and safety of Li–S batteries. Optimization of conventional organic solvents(including ether and carbonate) by fluorination to form fluorinated electrolytes is a promising strategy for the practical application of Li–S batteries. The fluorinated electrolytes, owing to the high electronegativity of fluorine, possesses attractive physicochemical properties, including low melting point,high flash point, and low solubility of lithium polysulfide, and can form a compact and stable solid electrolyte interphase(SEI) with the lithium metal anode. Herein, we review recent advancements in the development of fluorinated electrolytes for use in Li–S batteries. The effect of solvent molecular structure on the performance of Li–S batteries and the formation mechanism of SEI on the cathode and anode sides are analyzed and discussed in detail. The remaining challenges and future perspectives of fluorinated electrolytes for Li–S batteries are also presented.展开更多
Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers. The resultant latex and its film were characterized with dynamic light scattering ...Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers. The resultant latex and its film were characterized with dynamic light scattering detector and contact angle meter. Influences of amount of DMDAAC on the properties of resultant latex and its film were investigated in detail. Results show that the particle size of the latex has the minimum value knd the zeta potential of the latex is increased when the amount of DMDAAC is increased. In addition, the particle size of the latex is unimodal distribution when the amount of DMDAAC is not more than 2.5%. However, the particle size of the latex is bimodal distribution when the amount of DMDAAC is more than 2.5%. The contact angle is varied slightly with the increase of amount of DMDAAC when it is not more than 2.5%. Nevertheless, the contact angle is decreased with the increase of the amount of DMDAAC when it is more than 2.5%.展开更多
Three novel fluorinated cationic surfactants were prepared by adopting perfluoro-2-methy1-2-pentene as raw substrate. The as-obtained fluorinated cationic surfactants exhibited excellent surface properties, all of the...Three novel fluorinated cationic surfactants were prepared by adopting perfluoro-2-methy1-2-pentene as raw substrate. The as-obtained fluorinated cationic surfactants exhibited excellent surface properties, all of them can reduce the surface tension of water to below 20.00mN/m at the critical micelle concentrations （CMC）. The incorporation of SDS, AOS, APG or LAB into 2-（4-（3,3,4,4,5,5,5-heptafluoro- 2,2-bis（trifluoromethyl）pentyl）benzamido）-N,N-dimethylethana-mine oxide 4a could generate much lower CMC and surface tension value at the CMC than individual 4a. Especially, the surface tension values of that combined APG/4a can be reduced to 17.31 mN/m. The excellent surface activities and their remarkable compatibility to various types of hydrocarbon surfactants make them as sustainable alternatives to PFOA （perfluorooctanoic acid, C7F15CO2H） and PFOS （perfluorooctane sulphonate, C8F17SO3X, with X = K, Na, H）.展开更多
The pressure drop during production in the near-wellbore zone of gas condensate reservoirs causes condensate formation in this area.Condensate blockage in this area causes an additional pressure drop that weakens the ...The pressure drop during production in the near-wellbore zone of gas condensate reservoirs causes condensate formation in this area.Condensate blockage in this area causes an additional pressure drop that weakens the effective parameters of production,such as permeability.Reservoir rock wettability alteration to gas-wet through chemical treatment is one of the solutions to produce these condensates and eliminate condensate blockage in the area.In this study,an anionic fluorinated surfactant was synthesized and used for chemical treatment and carbonate rock wettability alteration.The synthesized surfactant was characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.Then,using surface tension tests,its critical micelle concentration(CMC)was determined.Contact angle experiments on chemically treated sections with surfactant solutions and spontaneous imbibition were performed to investigate the wettability alteration.Surfactant adsorption on porous media was calculated using flooding.Finally,the surfactant foamability was investigated using a Ross-Miles foam generator.According to the results,the synthesized surfactant has suitable thermal stability for use in gas condensate reservoirs.A CMC of 3500 ppm was obtained for the surfactant based on the surface tension experiments.Contact angle experiments show the ability of the surfactant to chemical treatment and wettability alteration of carbonate rocks to gas-wet so that at the constant concentration of CMC and at 373 K,the contact angles at treatment times of 30,60,120 and 240 min were obtained 87.94°,93.50°,99.79°and 106.03°,respectively.However,this ability varies at different surfactant concentrations and temperatures.The foamability test also shows the suitable stability of the foam generated by the surfactant,and a foam half-life time of 13 min was obtained for the surfactant at CMC.展开更多
A novel fluorinated triblock copolymer incorporating 2-ethylhexyl methacrylate （EHMA）, tert-butyl methacrylate （tBMA） and 1H,1H,2H,2H-perfluorodecyl acrylate （FA） （PEHMA-b-PtBMA-b-PFA） was first synthesized us...A novel fluorinated triblock copolymer incorporating 2-ethylhexyl methacrylate （EHMA）, tert-butyl methacrylate （tBMA） and 1H,1H,2H,2H-perfluorodecyl acrylate （FA） （PEHMA-b-PtBMA-b-PFA） was first synthesized using three successive reversible addition fragmentation chain transfer （RAFT） polymerization and the subsequent hydrolyzing at acidic condition. The as-fabricated triblock copolymer exhibited an interesting morphology evolution from the multi-compartment rod-like structure to spherical structure along with the addition of a selective solution. At the same time, a visible phase separation domain could be seen in the core area due to the existence of fluorocarbon segments. Furthermore, the self- assembly behavior of the triphilic copolymer at different pH was also verified by transmission electron microscopy, as well as the dynamic light scattering. These stimuli-responsive multi-compartment nanostructures may have potential applications in drug delivery.展开更多
Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance;thus,they are considered as a promising solution for advanced lithium-ion batter...Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance;thus,they are considered as a promising solution for advanced lithium-ion batteries carrying both high-energy density and high safety.Moreover,the fluorinated electrolytes are widely used to form stable electrolyte interphase,due to their chemical reactivity with lithiated graphite or lithium.However,the influence of this reactivity on the thermal safety of batteries is seldom discussed.Herein,we demonstrate that the flame-retardant fluorinated electrolytes help to reduce the flammability,while the lithium-ion batteries with flame-retardant fluorinated electrolytes still undergo thermal runaway and disclose their different thermal runaway pathway from that of battery with conventional electrolyte.The reduction in fluorinated components(e.g.,LiPF 6 and fluoroethylene carbonate(FEC))by fully lithiated graphite accounts for a significant heat release during battery thermal runaway.The 13%of total heat is sufficient to trigger the chain reactions during battery thermal runaway.This study deepens the understanding of the thermal runaway mechanism of lithium-ion batteries employing flame-retardant fluorinated electrolytes,providing guidance on the concept of electrolyte design for safer lithium-ion batteries.展开更多
With the increase of herbicide-resistant weeds, novel, more selective and even more potent herbicides to control weeds are needed. In this paper, a series of N-fluorinated phenyl-N＇-pyrimidyl urea derivatives were sy...With the increase of herbicide-resistant weeds, novel, more selective and even more potent herbicides to control weeds are needed. In this paper, a series of N-fluorinated phenyl-N＇-pyrimidyl urea derivatives were synthesized and screened for their herbicidal activities against Amaranthus retroflexus （AR） and Setaria viridis （ SV）. Compound 2S （N-（3-trifluoromethylphenyl）-N＇-（2-amino-4-chloro-6-methylpyr- imidyl） urea） exhibited marked herbicidal activity against SV（IC50 =11.67 mg/L） and is more potent than bensulfuron （IC50= 27.45 mg/L）, a commercially available herbicide. A statistically significant CoMFA model with high prediction abilities （q2 = 0.869, r2 = 0.989） was obtained.展开更多
基金supported by the National Natural Science Foundation of China(No.12235006)the National Key Research and Development Program of China(No.2020YFE0202002.
文摘X-ray detectors show potential applications in medical imaging,materials science,and nuclear energy.To achieve high detection efficiency and spatial resolution,many conventional semiconductor materials,such as amorphous selenium,cadmium telluride zinc,and perovskites,have been utilized in direct conversion X-ray detectors.However,these semiconductor materials are susceptible to temperature-induced performance degradation,crystallization,delamination,uneven lattice growth,radiation damage,and high dark current.This study explores a new approach by coupling an FC40 electronic fluorinated liquid with a specialized high-resolution and high-readout-speed complementary metal-oxide-semiconductor(CMOS)pixel array,specifically the Topmetal II−chip,to fabricate a direct conversion X-ray detector.The fluorinated liquid FC40(molecular formula:C_(21)F_(48)N_(2))is an electronic medium that is minimally affected by temperature and displays no issues with uniform conductivity.It exhibits a low dark current and minimal radiation damage and enables customizable thickness in X-ray absorption.This addresses the limitations inherent in conventional semiconductor-based detectors.In this study,simple X-ray detector imaging tests were conducted,demonstrating the excellent coupling capability between FC40 electronic fluorinated liquid and CMOS chips by the X-ray detector.A spatial resolution of 4.0 lp/mm was measured using a striped line par card,and a relatively clear image of a cockroach was displayed in the digital radiography imaging results.Preliminary test results indicated the feasibility of fabricating an X-ray detector by combining FC40 electronic fluorinated liquid and CMOS chips.Owing to the absence of issues related to chip-material coupling,a high spatial resolution could be achieved by reducing the chip pixel size.This method presents a new avenue for studies on novel liquid-based direct conversion X-ray detectors.
基金financially supported by the Natural Science Foundation of Shandong Province(Nos.ZR2021ME055,ZR2022QB170 and ZR2022MB034)the Foundation(No.GZKF202128)of State Key Laboratory of Biobased Material and Green Papermaking,Qilu University of Technology,Shandong Academy of Sciencesthe Development Program Project of Young Innovation Team of Institutions of Higher Learning in Shandong Province.
文摘It is urgent to develop high-performance polyimide(PI)films that simultaneously exhibit high transparency,exceptional thermal stability,mechanical robustness,and low dielectric to fulfil the requirements of flexible display technologies.Herein,a series of fluorinated polyimide films(FPIs)were fabricated by the condensation of 5,5′-(perfluoropropane-2,2-diyl)bis(isobenzofuran-1,3-dione)(6FDA)and the fluorinated triphenylmethane diamine monomer(EDA,MEDA and DMEDA)with heat-crosslinkable tetrafluorostyrene side groups,which was incorporated by different numbers of methyl groups pendant in the ortho position of amino groups.Subsequently,the FPI films underwent heating to produce crosslinking FPIs(C-FPIs)through the self-crosslinking of double bonds in the tetrafluorostyrene.The transparency,solvent resistance,thermal stability,mechanical robustness and dielectric properties of FPI and C-FPI films can be tuned by the number of methyl groups and crosslinking,which were deeply investigated by virtue of molecular dynamics(MD)simulations and density functional theory(DFT).As a result,all the films exhibited exceptional optically colorless and transparent,with transmittance in the visible region of 450-700 nm exceeding 79.9%,and the cut-off wavelengths(λ_(off))were nearly 350 nm.The thermal decomposition temperatures at 5% weight loss(T_(d5%))for all samples exceeded 504℃.These films exhibited a wide range of tunable tensile strength(46.5-75.1 MPa).Significantly,they showed exceptional dielectric properties with the dielectric constant of 2.3-2.5 at full frequency(10^(7)-20 Hz).This study not only highlights the relationship between the polymer molecular structure and properties,but offer insights for balancing optical transparency,heat resistance and low dielectric constant in PI films.
基金supported by Natural Science Foundation of Shandong Province(No.ZR2022MB033)Science and Technology Bureau of Jinan City(No.2021GXRC105)University of Jinan Disciplinary Cross-Convergence Construction Project 2023(No.XKJC-202302)。
文摘The construction of monodisperse microporous organic microspheres is deemed a challenging issue,primarily due to the difficulty in achieving both high microporosity and uniformity within the microspheres.In this study,a series of fluorinated monodisperse microporous microspheres are fabricated by solvothermal precipitation polymerization.The resulting fluorous methacrylate-based microspheres achieved higher than 400 m^(2)/g surface area,along with a yield of over 90%for the microspheres.Through comprehensive characterization and simulation methods,we discovered that the introduction of fluorous methacrylate monomers at high loading levels is the key factor contributing to the formation of the microporosity within the microspheres.The controlled temperature profile was found to be advantageous for achieving a high yield of microspheres and increased uniformity.Two-dimensional assemblies of these fluorinated microsphere arrays exhibited superhydrophobicity,superolephilicity,and water sliding angles below 10°.Furthermore,a three-dimensional assembly of the fluorinated microporous microsphere in a chromatographic column demonstrated significant improvement in the separation of Engelhardt agent compared to commercial columns.Our work offers a novel approach to constructing fluorinated monodisperse microporous microspheres for advanced applications.
基金funded by the National Key Research and Development Program of China(2022YFE0110500)National Natural Science Foundation of China(22376161,52373154,52103181)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe Interdisciplinary Project in Environmental Science and Engineering of Tongji University(2023-3-YB-02)。
文摘Fluorinated gases(F-gases)play a vital role in the chemical industry and in the fields of air conditioning,refrigeration,health care,and organic synthesis.However,the direct emission of waste gases containing F-gases into the atmosphere contributes to greenhouse effects and generates toxic substances.Developing porous materials for the energy-efficient capture,separation,and recovery of F-gases is highly desired.Recently,as a highly designable porous adsorbents,metal–organic frameworks(MOFs)exhibit excellent selective sorption performance toward F-gases,especially for the recognition and separation of different F-gases with highly similar properties,showing their great potential in F-gases control and recovery.In this review,we discuss the capture and separation of F-gases and their azeotropic,near-azeotropic,and isomeric mixtures in various application scenarios by MOFs,specifically classify and analyze molecular interaction between F-gases and MOFs,and interpret the mechanisms underlying their high performance regarding both adsorption capacity and selectivity,providing a repertoire for future materials design.Challenges faced in the transformation research roadmap of MOFs adsorbent separation technologies toward F-gases are also discussed,and areas for future research endeavors are highlighted.
基金funded by the Opening Fund of Key Laboratory of Higher Education of Sichuan Province for Enterprise Informationalization and Internet of Things(No.2023WYJ06)the Yadong Wu Talent Program(No.H31225001)+1 种基金supported in part by the Defense Industrial Technology Development Program(No.JCKY2022404C001)by the Sichuan Provincial Key Lab of Process Equipment and Control’s Project(No.GK201509)。
文摘In the research and production of fluorinated materials,large volumes of unstructured textual data are generated,characterized by high heterogeneity and fragmentation.These issues hinder systematic knowledge integration and efficient utilization.Constructing a knowledge graph for fluorinated materials processing is essential for enabling structured knowledge management and intelligent applications.Among its core components,Named Entity Recognition(NER)plays an essential role,as its accuracy directly impacts relation extraction and semantic modeling,which ultimately affects the knowledge graph construction for fluorinated materials.However,NER in this domain faces challenges such as fuzzy entity boundaries,inconsistent terminology,and a lack of high-quality annotated corpora.To address these problems,(i)We first construct a domain-specific NER dataset by combining manual annotation with an improved Easy Data Augmentation(EDA)strategy;(ii)Secondly,we propose a novel model,RRC-ADV,which integrates RoBERTa-wwm for dynamic contextual word representation,adversarial training to improve robustness against boundary ambiguity,and a Residual BiLSTM(ResBiLSTM)to enhance sequential feature modeling.Further,a Conditional Random Field(CRF)layer is incorporated for globally optimized label prediction.Experimental results demonstrate that RRC-ADV achieves an average F1 score of 89.23%on the self-constructed dataset,significantly outperforming baseline models.The model exhibits strong robustness and adaptability within the domain of fluorinated materials.Our work enhances the accuracy of NER in the fluorinated materials processing domain and paves the way for downstream tasks such as relation extraction in knowledge graph construction.
基金support of the National Natural Science Foundation of China(Grant 22278340&22078272)。
文摘Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene-co-p-terphenyl piperidinium)(PPTP3F_(x)-DIL)AEMs with different fluorinated monomers for high performance AEMFCs.The polymerization of fluorinated monomers with other aryl monomers can effectively promote the separation of microphase in the membrane.It also has a high OH-conductivity at a low swelling.The membrane(PPTP3F_(4)-DIL)prepared by polycondensation of 2,2,2-trifluoro-1-(p-tolyl)ethan 1-one monomer achieves a high conductivity of 168.5 mS cm^(-1)at 80℃.At the same time,the water uptake is 40.0%and the swelling ratio is 12.1%.In addition,these membranes also have good mechanical properties and alkaline stability.After 1440 h of treatment in a NaOH(2 M)solution at 80℃,PPTP3F_(x)-DIL still maintains excellent tensile strength(>30.3 MPa)and elongation at break(>43.4%),and the conductivity retention of the PPTP3F_(1)-DIL membrane is 90.3%.The PPTP3F_(4)-DIL-based single cell exhibits a high peak power density(918.1 mW cm^(-2))and excellent durability(100 h)at 80℃.Therefore,these PPTP3F_(x)-DIL membranes have a wide range of applications in AEMFCs.
基金Natural Science Foundation of China(grant nos 22075031)Jilin Provincial Science&Technology Department(grant nos 20220201105GX)Jilin Provincial Development and Reform Commission(grant nos 2023C034-4)。
文摘The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely investigated.However,the question of the“trade-off”between AEM ionic conductivity and dimensional stability remains difficult.The strategy of inducing microphase separation to improve the performance of AEM has attracted much attention recently,but the design of optimal molecular structures is still being explored.Here,this work introduced different ratios of 3-bromo-1,1,1-trifluoroacetone(x=40,50,and 60)into the main chain of poly(p-terphenylene isatin).Because fluorinated groups have excellent hydrophobicity,hydrophilic hydroxyl-containing side chains are introduced to jointly adjust the formation of phase separation structure.The results show that PTI-PTF_(50)-NOH AEM with the appropriate fluorinated group ratio has the best ionic conductivity and alkali stability under the combined effect of both.It has an ionic conductivity of 133.83 mS cm^(-1)at 80°C.In addition,the OH-conductivity remains at 89%of the initial value at 80°C and 3 M KOH for 1056 h of immersion.The cell polarization curve based on PTI-PTF_(50)-NOH shows a power density of 734.76 mW cm^(-2)at a current density of 1807.7 mA cm^(-2).
基金supported by the National Natural Science Foundation of China(No.22375123)the Shuguang Program of Shanghai Education Development Foundation,the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SXTD012)。
文摘Fluorinated fused azobenzene boron(FBAz)is a novel electron-deficient building block for polymer electron acceptors in all-polymer solar cells(all-PSC).The B←N bridging units impart a fixed configuration and low-lying LUMO/HOMO energy.Three polymer acceptor materials(P2f,P3f and P5f)with different fluorine substitution positions by copolymerizing FBAz with indacenodithiophene(IDT),are synthesized and investigated to study the influence of fluorinated forms on the all-polymer solar cell performance.The FBAz units are synthesized in just three steps,facilitating the straightforward production of polymer acceptors P2f,P3f,and P5f.These acceptors exhibit strong light absorption in the visible to near-infrared range of 500-1000nm and possess suitable LUMO/HOMO energy levels of-3.99/-5.66 eV which are very complementary to that(E_(LUMO/HOMO)=-3.59/-5.20 eV)of the widely-used polymer donor poly[(ethylhexylthiophenyl)-benzodithiophene-(ethylhexyl)-thienothiophene](PTB7-Th).All-polymer solar cells(all-PSCs)with PTB7-Th as electron donor and P3f as electron acceptor exhibits highest power conversion efficiencies(PCE)2.70%.When PC_(61)BM is added as the third component,the device efficiency can reach 5.36%.These preliminary results indicate that FBAz is a promising strong electron acceptor for the development of n-type polymer semiconductors,especially in organic photovoltaics(OPVs).To the best of our knowledge,this is the first example demonstrating the unique photovoltaic properties of the N=N double bond as an acceptor material.
基金financially supported by the National Natural Science Foundation of China(No.52271084)the Guangdong Basic and Applied Basic Research Foundation,China(No.2021B1515020056)the Open Research Fund of Songshan Lake Materials Laboratory,China(No.2022SLABFK06)。
文摘To improve the friction and wear performance at room and elevated temperatures,Ti48Al2Nb2Cr(at.%)alloy was anodically fluorinated in an NH_(4)F-containing electrolyte.The effects of anodic fluorination on the friction coefficient,wear rate,wear track morphology,and adhesion strength between the oxide scale and substrate were investigated.Results showed that the in-situ formation of Al_(2)O_(3)-enriched oxide scale was promoted due to fluorine effect,by which the surface hardness and wear resistance were both enhanced.After the friction and wear test,no noticeable changes were found on the fluorinated Ti48Al2Nb2Cr,whilst severe abrasion was evident on the GCr15 counterpart.This indicates that anodic fluorination could effectively enhance the friction and wear performance of Ti48Al2Nb2Cr alloy.At elevated temperatures,the dominant wear mechanism of the fluorinated Ti48Al2Nb2Cr/GCr15 pair was oxidation wear and adhesive wear.
基金supported by the Ministry of Science and Technology of China[grants 2021YFA1302602]the National Natural Science Foundation of China[grants 21925406,21991082,21921004]the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0540000 and YSBR-068).
文摘Although the parallel incorporation of fluorinated aromatic amino acids(FAAAs)into proteins has been explored since 2010,the corresponding ^(19)F NMR investigation has been lacking to date.To assess the potential of the parallel incorporation of FAAAs in studies of protein structure,dynamics and interactions,we examine the protein yields,fluorine incorporation efficiencies,and ^(19)F NMR spectra upon simultaneously incorporating FAAAs including 3-fluorotyrosine(3FY),4-fluorophenylalanine(4FF)and 5-fluorotryptophan(5FW)into two model proteins:the structured protein GB1 domain(GB1)and the intrinsically disordered protein a-synuclein(a-syn).We found that the simultaneous incorporation of 3FY and 5FW achieved higher efficiency than combinations of 4FF and 5FW,4FF and 3FY,or 3FY,4FF and 5FW.Moreover,incorporating more types of FAAAs leads to a reduction in overall yield.The ^(19)F spectra of 3FY,4FF and 5FW residues in α-syn and GB1 exhibited good dispersion of chemical shifts.However,the GB1 spectrum showed complexity due to incomplete fluorination and interactions within aromatic cluster.This complexity could be significantly reduced by supplementing the medium with natural aromatic amino acids.To validate the advantage of ^(19)F NMR spectrum,we use 3FY-4FF-5FW-F94W-α-syn to investigate the interaction between α-syn and sodium dodecyl sulphate(SDS)micelle.Our study demonstrates that ^(19)F NMR spectroscopy of proteins with parallel incorporation of FAAAs provides a valuable tool for investigating protein conformation,dynamics and interactions.
基金Financial support from the Fundamental Research Foundation of Beijing Institute of Technology (No.20070442005)
文摘A novel fluorinated polyurethane （FPU） with fluorine-containing pendent groups was prepared by using fluorinated polyether glycol （PTMG-g-HFP） as a soft segment, 1,6-hexamethylene diisocyanate （HDI） or toluene diisocyanate （TD1） as a hard segment and 1,4-butanodiol （BDO） as a chain extender. FTIR, ^1H NMR, ^13C NMR and GPC were used to characterize the structure of the fluorinated polyurethane. Thermal stabilities of the fluorinated polyurethane and the corresponding hydrogenated polyurethane were studied by TGA. XPS analysis at two different sampling depths for the fluorinated polyurethane was used to investigate the surface compositions of FPU. The results showed the fluorine enrichment on the surface of FPU.
基金financially supported by National Key Research and Development Program of China(Grant no.2018YFB010440)the National Natural Science Foundation of China(Grant nos.21761132030,21621091).
文摘Ethyl-(2,2,2-trifluoroethyl)carbonate(ETFEC)is investigated as a solvent component in high-voltage electrolytes for LiNi0.5Mn1.5O4(LNMO).Our results show that the self-discharge behavior and the high temperature cycle performance can be significantly improved by the addition of 10%ETFEC into the normal carbonate electrolytes,e.g.,the capacity retention improved from 65.3%to 77.1%after 200 cycles at 60℃.The main reason can be ascribed to the high stability of ETFEC which prevents large oxidation of the electrolyte on the cathode surface.In addition,we also explore the feasibility of electrolytes using single fluoriated-solvents with and without additives.Our results show that the cycle performance of LNMO material can be greatly improved in 1 MLiPF6+pure ETFEC-solvent system with 2 wt%ethylene carbonate(EC)or ethylene sulfate(DTD).The capacity retention of the LNMO materials is 93%after 300 cycles,even better than that of carbonate-based electrolytes.It is shown that the additives are oxidized on the surface of LNMO particles and contribute to the formation of cathode/electrolyte interphase(CEI)films.This composite CEI film plays a crucial role in suppressing the serious decomposition of the electrolyte at high voltage.
文摘This paper reported the oxidation of ethylbenzene catalyzed by fluorinated metalloporphyrins under mild conditions without any additives. The results showed that the cobalt(II)(5,10,15,20-tetrakis(pentafluorophenyl))porphyrin was the best catalyst among the fluorinated metalloporphyrins. The conversion of ethylbenzene reached 38.6%, the selectivity to acetophenone reached 94.0%, and the turnover number is 2719 under the optimal conditions.
基金the National Natural Science Foundation of China(Grant nos.51772089 and 21872046)the Youth 1000 Talent Program of China(Grant no.S2017JJJCQN0149)+2 种基金the Fundamental Research Funds for the Central Universitiesthe Outstanding Youth Scientist Foundation of Hunan Province(Grant no.S2019JJQNJJ0361)Natural Science Foundation of Hunan Province(Grant no.S2019JJQNJJ0361)。
文摘Lithium–sulfur(Li–S) batteries represent a "beyond Li-ion" technology with low cost and high theoretical energy density and should fulfill the ever-growing requirements of electric vehicles and stationary energy storage systems. However, the sulfur-based conversion reaction in conventional liquid electrolytes results in issues like the so-called shuttle effect of polysulfides and lithium dendrite growth, which deteriorate the electrochemical performance and safety of Li–S batteries. Optimization of conventional organic solvents(including ether and carbonate) by fluorination to form fluorinated electrolytes is a promising strategy for the practical application of Li–S batteries. The fluorinated electrolytes, owing to the high electronegativity of fluorine, possesses attractive physicochemical properties, including low melting point,high flash point, and low solubility of lithium polysulfide, and can form a compact and stable solid electrolyte interphase(SEI) with the lithium metal anode. Herein, we review recent advancements in the development of fluorinated electrolytes for use in Li–S batteries. The effect of solvent molecular structure on the performance of Li–S batteries and the formation mechanism of SEI on the cathode and anode sides are analyzed and discussed in detail. The remaining challenges and future perspectives of fluorinated electrolytes for Li–S batteries are also presented.
基金supported by the Science and Technology Department of Zhejiang Province under Grant No. 2010C31040the financial support of Zhejiang Provincial Natural Science Foundation of China(No. Y4100152)Zhejiang University of Technology Natural Science Foundation(No.20100202)
文摘Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers. The resultant latex and its film were characterized with dynamic light scattering detector and contact angle meter. Influences of amount of DMDAAC on the properties of resultant latex and its film were investigated in detail. Results show that the particle size of the latex has the minimum value knd the zeta potential of the latex is increased when the amount of DMDAAC is increased. In addition, the particle size of the latex is unimodal distribution when the amount of DMDAAC is not more than 2.5%. However, the particle size of the latex is bimodal distribution when the amount of DMDAAC is more than 2.5%. The contact angle is varied slightly with the increase of amount of DMDAAC when it is not more than 2.5%. Nevertheless, the contact angle is decreased with the increase of the amount of DMDAAC when it is more than 2.5%.
基金supported by the National Natural Science Foundation of China (No. 2167020782)the Science and Technology Commission of Shanghai Municipality (No. 15DZ2281500)
文摘Three novel fluorinated cationic surfactants were prepared by adopting perfluoro-2-methy1-2-pentene as raw substrate. The as-obtained fluorinated cationic surfactants exhibited excellent surface properties, all of them can reduce the surface tension of water to below 20.00mN/m at the critical micelle concentrations （CMC）. The incorporation of SDS, AOS, APG or LAB into 2-（4-（3,3,4,4,5,5,5-heptafluoro- 2,2-bis（trifluoromethyl）pentyl）benzamido）-N,N-dimethylethana-mine oxide 4a could generate much lower CMC and surface tension value at the CMC than individual 4a. Especially, the surface tension values of that combined APG/4a can be reduced to 17.31 mN/m. The excellent surface activities and their remarkable compatibility to various types of hydrocarbon surfactants make them as sustainable alternatives to PFOA （perfluorooctanoic acid, C7F15CO2H） and PFOS （perfluorooctane sulphonate, C8F17SO3X, with X = K, Na, H）.
文摘The pressure drop during production in the near-wellbore zone of gas condensate reservoirs causes condensate formation in this area.Condensate blockage in this area causes an additional pressure drop that weakens the effective parameters of production,such as permeability.Reservoir rock wettability alteration to gas-wet through chemical treatment is one of the solutions to produce these condensates and eliminate condensate blockage in the area.In this study,an anionic fluorinated surfactant was synthesized and used for chemical treatment and carbonate rock wettability alteration.The synthesized surfactant was characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.Then,using surface tension tests,its critical micelle concentration(CMC)was determined.Contact angle experiments on chemically treated sections with surfactant solutions and spontaneous imbibition were performed to investigate the wettability alteration.Surfactant adsorption on porous media was calculated using flooding.Finally,the surfactant foamability was investigated using a Ross-Miles foam generator.According to the results,the synthesized surfactant has suitable thermal stability for use in gas condensate reservoirs.A CMC of 3500 ppm was obtained for the surfactant based on the surface tension experiments.Contact angle experiments show the ability of the surfactant to chemical treatment and wettability alteration of carbonate rocks to gas-wet so that at the constant concentration of CMC and at 373 K,the contact angles at treatment times of 30,60,120 and 240 min were obtained 87.94°,93.50°,99.79°and 106.03°,respectively.However,this ability varies at different surfactant concentrations and temperatures.The foamability test also shows the suitable stability of the foam generated by the surfactant,and a foam half-life time of 13 min was obtained for the surfactant at CMC.
基金financially supported by the National Natural Science Foundation of China(Nos.51622301 and 51573046)Fundamental Research Funds for the Central Universities(Nos.B14018,WD1616010 and 222201717001)
文摘A novel fluorinated triblock copolymer incorporating 2-ethylhexyl methacrylate （EHMA）, tert-butyl methacrylate （tBMA） and 1H,1H,2H,2H-perfluorodecyl acrylate （FA） （PEHMA-b-PtBMA-b-PFA） was first synthesized using three successive reversible addition fragmentation chain transfer （RAFT） polymerization and the subsequent hydrolyzing at acidic condition. The as-fabricated triblock copolymer exhibited an interesting morphology evolution from the multi-compartment rod-like structure to spherical structure along with the addition of a selective solution. At the same time, a visible phase separation domain could be seen in the core area due to the existence of fluorocarbon segments. Furthermore, the self- assembly behavior of the triphilic copolymer at different pH was also verified by transmission electron microscopy, as well as the dynamic light scattering. These stimuli-responsive multi-compartment nanostructures may have potential applications in drug delivery.
基金This work is funded by National Natural Science Foundation of China(Grant No.52006115)Ministry of Science and Technology of China(Grant No.2019YFE0100200)+3 种基金National Natural Science Foundation of China(Grant No.52076121)China National Postdoctoral Program for Innovative Talents(Grant No.BX20190162)China Postdoctoral Science Foundation(Grant No.2019M660631)the Tsinghua University Initiative Scientific Research Program(Grant No.2019Z02UTY06).
文摘Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance;thus,they are considered as a promising solution for advanced lithium-ion batteries carrying both high-energy density and high safety.Moreover,the fluorinated electrolytes are widely used to form stable electrolyte interphase,due to their chemical reactivity with lithiated graphite or lithium.However,the influence of this reactivity on the thermal safety of batteries is seldom discussed.Herein,we demonstrate that the flame-retardant fluorinated electrolytes help to reduce the flammability,while the lithium-ion batteries with flame-retardant fluorinated electrolytes still undergo thermal runaway and disclose their different thermal runaway pathway from that of battery with conventional electrolyte.The reduction in fluorinated components(e.g.,LiPF 6 and fluoroethylene carbonate(FEC))by fully lithiated graphite accounts for a significant heat release during battery thermal runaway.The 13%of total heat is sufficient to trigger the chain reactions during battery thermal runaway.This study deepens the understanding of the thermal runaway mechanism of lithium-ion batteries employing flame-retardant fluorinated electrolytes,providing guidance on the concept of electrolyte design for safer lithium-ion batteries.
基金supported by the National Natural Science Foundation of China(No.30900935)the Fundamental Research Funds for the Central Universities(Nos.2011PY086,2011PY039)
文摘With the increase of herbicide-resistant weeds, novel, more selective and even more potent herbicides to control weeds are needed. In this paper, a series of N-fluorinated phenyl-N＇-pyrimidyl urea derivatives were synthesized and screened for their herbicidal activities against Amaranthus retroflexus （AR） and Setaria viridis （ SV）. Compound 2S （N-（3-trifluoromethylphenyl）-N＇-（2-amino-4-chloro-6-methylpyr- imidyl） urea） exhibited marked herbicidal activity against SV（IC50 =11.67 mg/L） and is more potent than bensulfuron （IC50= 27.45 mg/L）, a commercially available herbicide. A statistically significant CoMFA model with high prediction abilities （q2 = 0.869, r2 = 0.989） was obtained.
