CONSPECTUS:Polymer−nanoparticle(NP)composites with ultrahigh loadings(more than 50 vol%)of NPs possess exceptional mechanical,transport,and physical properties,making them valuable for various applications.However,pro...CONSPECTUS:Polymer−nanoparticle(NP)composites with ultrahigh loadings(more than 50 vol%)of NPs possess exceptional mechanical,transport,and physical properties,making them valuable for various applications.However,producing such polymer−NP composites poses significant challenges due to difficulties associated with mixing and dispersing high fractions of NPs in polymers.A promising approach to overcome these challenges involves infiltrating a polymer into the interstitial pores of a disordered NP packing,resulting in a polymer-infiltrated NP film(PINF).Recently,versatile capillarity-driven techniques have emerged,successfully enabling the production of PINFs.These capillarity-driven techniques allow for the fabrication of homogeneous(fully infiltrated),nanoporous(partially infiltrated),and heterostructured PINFs.Infiltrating polymers into stiff but brittle NP packings increases their toughness,attributed to the formation of polymer bridges between adjacent NPs or interchain entanglements.The physical confinement of polymer within the interstitial pore also enhances thermal stability and heat transfer of PINFs.Additionally,the tunable nanoporosity and heterostructures of PINFs lead to unique optical properties suitable for various practical applications.In this Account,we present recent advances and progress in capillarity-based techniques for the fabrication of PINFs and provide a summary of our latest finding on the infiltration process and the properties of PINFs which we have obtained after the publication of our 2021 review paper.We also discuss the stability of the resulting PINFs and demonstrate some practical applications.We conclude the Account by outlining the fundamental research and application directions for the future.In Section 2,we detail capillarity-driven techniques to infiltrate a polymer into a disordered packing of NPs,specifically capillary rise infiltration(CaRI),solvent-driven infiltration of polymer(SIP),and leaching-enabled CaRI(LeCaRI).The CaRI and SIP techniques involve thermal and solvent vapor annealing processes,respectively,while the LeCaRI technique is performed at room temperature without any solvent.For each technique,factors influencing the extent and dynamics of polymer infiltration,including nanoconfinement and polymer−NP surface interactions,are explained.In Section 3,we focus on the mechanical properties and thermal/photo degradation behaviors of the PINFs,which are closely linked to their stability,and explain how nanoconfinement and polymer−NP surface interactions affect these properties.We show that kinetics of infiltration and the properties of PINFs have nontrivial and at times counterintuitive dependence on the extent of nanoconfinement and the interaction strengths between polymers and NPs.In Section 4,we explore some practical applications of PINFs,demonstrating their multifunctionality in areas such as antireflection coatings and antifouling coatings.We highlight how PINFs with tunable refractive indices serve as effective antireflection coatings and how lubricant depletion-resistant slippery liquid-infused porous surfaces can be developed.In Section 5,we discuss the remaining challenges associated with capillarity-driven techniques and PINFs that need to be addressed and explore potential applications such as functional films,coatings,and membranes for sustainable development.展开更多
Glioblastomas belong to the most aggressive human cancers with short survival times.Due to the blood-brainbarrier,they are mostly inaccessible to traditional chemotherapy.We have recently shown that doxorubicin boundt...Glioblastomas belong to the most aggressive human cancers with short survival times.Due to the blood-brainbarrier,they are mostly inaccessible to traditional chemotherapy.We have recently shown that doxorubicin boundto polysorbate-coated nanoparticles crossed the intact blood-brain barrier,thus reaching therapeutic concentra-tions in the brain.Here,we investigated the therapeutic potential of this formulation of doxorubicin in vivo using ananimal model created by implantation of 101/8 glioblastoma tumor in rat brains.Groups of 5-8 glioblastoma-展开更多
Electrochemical nitrate(NO_(3)^(-))reduction reaction(eNO_(3)RR)to ammonia(NH3)provides a promising route for both water conservation and green ammonia synthesis.Although various catalysts were designed for the eNO_(3...Electrochemical nitrate(NO_(3)^(-))reduction reaction(eNO_(3)RR)to ammonia(NH3)provides a promising route for both water conservation and green ammonia synthesis.Although various catalysts were designed for the eNO_(3)RR and great achievements have been achieved,it is still a challenge to realize selective eNO_(3)RR to NH3at low concentration for the competing hydrogen evolution reaction(HER)and poor mass transfer of NO_(3)^(-).Herein,we designed a tandem catalyst of Pd nanoparticle loaded Cu_(2)O hierarchical nanofiber(Pd-Cu_(2)O)to improve eNO_(3)RR performance at low nitrate concentration.The Pd-Cu_(2)O shows a faraday efficiency(FE)of 95.80%and an ammonia selectivity of 97.34%at a comparatively low applied potential of-0.15 V versus RHE with low concentration.Besides,it exhibits excellent nitrate removal effects,the residual concentration of nitrate-N was only 7.22 ppm at-0.15 V.Electrochemical characterizations indicate that the abundant secondary heterojunction structures and the tandem effects of Pd-Cu_(2)O synergistic ally accelerate the transfer and conversion of NO_(3)^(-)and improve the dynamic of eNO_(3)RR at low concentration.Furthermore,the operando electrochemical impedance spectroscopy(EIS)and density functional theory(DFT)calculations suggested the tandem effects of Pd-Cu_(2)O improved the adsorption of NO_(3)^(-)and*H and thus promoted the dynamics of eNO_(3)RR at low concentration.The findings highlight the tandem effects of Pd-Cu_(2)O and provide an effective strategy for designing electrocatalysts that can be applied to low concentration and low applied potential conditions.展开更多
The Ullmann coupling reaction of aromatic halides is the most challenging C–C coupling reaction.Both MOF-based and MOF-deriffed types of catalysts haffe recently proffided useful nanocatalysts for a ffariety of react...The Ullmann coupling reaction of aromatic halides is the most challenging C–C coupling reaction.Both MOF-based and MOF-deriffed types of catalysts haffe recently proffided useful nanocatalysts for a ffariety of reactions,but they haffe rarely been compared.Herein,the Ullmann-type aryl iodide homocoupling is effciently catalyzed by gold and palladium nanoparticles(NPs)loaded on ZIF-8 before(ZIF-8-based nanocatalyst:M@ZIF-8)and after calcination(ZIF-8-deriffed catalyst:M@CN).The nanocatalysts M@ZIF-8(M=Pd,Au)are found to be more effcient than the catalysts M@CN.Pd@ZIF-8 exhibits better perform ances than those of Au@ZIF-8 for a series of aryl iodides,but in the case of 4-nitro-iodobenzene,deshy droiodination was obserffed besides the coupling product.Mechanisms are proposed and discussed for both Au(0)and Pd(0)nanocatalysts.展开更多
The primary aim of the study was to prepare narrow sized polymeric nanoparticles by implementing few modifications to the conventional nanoprecipitation technique and to evaluate the effect of various process paramete...The primary aim of the study was to prepare narrow sized polymeric nanoparticles by implementing few modifications to the conventional nanoprecipitation technique and to evaluate the effect of various process parameters on prepared polymeric nanoparticles.Eudragit E 100 nanoparticles were prepared by modified nanoprecipitation technique and step-by-step optimization was carried out to evaluate the effect of various process parameters such as organic solvent,polymer concentration,percentage of organic solvent,mode of addition of organic solvent in to aqueous phase,volume of aqueous phase,poloxamer 188 concentration,β-cyclodextrin concentration,temperature generated during sonication process,sonication duration,and drug concentration on the particle size,surface area,distribution width and uniformity of the prepared nanoparticles.The optimized process parameters were implemented to fabricate dual drug loaded Eudragit E 100 nanoparticles which were spherical in shape with mean particle size in the range of 118 to 140 nm,polydispersity index in the range of 0.187 to 0.254 and zeta potential in the range of 16.6 to 28.8 mV.Thus developed modified nanoprecipitation method can be used to fabricate narrow sized polymeric nanoparticles.展开更多
Semiconductor photocatalysis provides a promising potential solution to the challenging issue of clean energy production.Construction of multijunction systems is an effective strategy to overcome the serious drawbacks...Semiconductor photocatalysis provides a promising potential solution to the challenging issue of clean energy production.Construction of multijunction systems is an effective strategy to overcome the serious drawbacks of fast charge recombination and the limited visible-light absorption of semiconductor photocatalysts.Here,we report a novel quaternary heterogeneous photocatalyst fabricated by loading Ag nanoparticles onto ZnO nanowires and subsequent simultaneous formation of core/shell structured ZnO@ZnS and Ag@Ag_(2)S heterojunctions via a one-step anion-exchange sulfuration reaction process.The resulting four-component ZnO@ZnS/Ag@Ag_(2)S multijunction photocatalyst exhibits a high hydrogen evolution activity(140.3μmol g^(-1))under simulated solar light irradiation in 5 h,far exceeding those of bare ZnO(30.8μmol g^(-1)),ZnO@ZnS(92.8μmol g^(-1))and ZnO/Ag(45.1μmol g^(-1))counterparts.The enhanced photocatalytic activity can be attributed to the synergetic effect of the formation of both Z-scheme and type II core/shell heterojunctions,favoring light absorption and separation of photogenerated electron-hole pairs in the composite.This work provides a facile,controlled method for the fabrication of multicomponent heterostructures used for efficient solar water splitting.展开更多
Two low-dimensional Cu(I)boron imidazolate frameworks(BIFs),[CuBH(bim)_(3)]_(n)(BIF-40;bim=benzimidazolate)and[CuBH(im)_(3)]_(n)(BIF-6,im=imidazolate),have been synthesized and both of them display unique mechanochrom...Two low-dimensional Cu(I)boron imidazolate frameworks(BIFs),[CuBH(bim)_(3)]_(n)(BIF-40;bim=benzimidazolate)and[CuBH(im)_(3)]_(n)(BIF-6,im=imidazolate),have been synthesized and both of them display unique mechanochromism.In addition,BIF-40 showed reducing activity due to the rich B–H bonds in the structure,and it was employed to load AuPd bimetal nanoparticles through a one-step process for further catalysis.The corresponding mechanism involving a grinding process between chains or layers is discussed in detail.This work not only provides compelling evidence for designing and applying coordination polymers as mechanochromic materials,but also develops an eco-friendly strategy for loading bimetallic NPs into BIFs.展开更多
基金supported by Penn MRSEC(NSF DMR 1720530)and NSF CBET-1933704.
文摘CONSPECTUS:Polymer−nanoparticle(NP)composites with ultrahigh loadings(more than 50 vol%)of NPs possess exceptional mechanical,transport,and physical properties,making them valuable for various applications.However,producing such polymer−NP composites poses significant challenges due to difficulties associated with mixing and dispersing high fractions of NPs in polymers.A promising approach to overcome these challenges involves infiltrating a polymer into the interstitial pores of a disordered NP packing,resulting in a polymer-infiltrated NP film(PINF).Recently,versatile capillarity-driven techniques have emerged,successfully enabling the production of PINFs.These capillarity-driven techniques allow for the fabrication of homogeneous(fully infiltrated),nanoporous(partially infiltrated),and heterostructured PINFs.Infiltrating polymers into stiff but brittle NP packings increases their toughness,attributed to the formation of polymer bridges between adjacent NPs or interchain entanglements.The physical confinement of polymer within the interstitial pore also enhances thermal stability and heat transfer of PINFs.Additionally,the tunable nanoporosity and heterostructures of PINFs lead to unique optical properties suitable for various practical applications.In this Account,we present recent advances and progress in capillarity-based techniques for the fabrication of PINFs and provide a summary of our latest finding on the infiltration process and the properties of PINFs which we have obtained after the publication of our 2021 review paper.We also discuss the stability of the resulting PINFs and demonstrate some practical applications.We conclude the Account by outlining the fundamental research and application directions for the future.In Section 2,we detail capillarity-driven techniques to infiltrate a polymer into a disordered packing of NPs,specifically capillary rise infiltration(CaRI),solvent-driven infiltration of polymer(SIP),and leaching-enabled CaRI(LeCaRI).The CaRI and SIP techniques involve thermal and solvent vapor annealing processes,respectively,while the LeCaRI technique is performed at room temperature without any solvent.For each technique,factors influencing the extent and dynamics of polymer infiltration,including nanoconfinement and polymer−NP surface interactions,are explained.In Section 3,we focus on the mechanical properties and thermal/photo degradation behaviors of the PINFs,which are closely linked to their stability,and explain how nanoconfinement and polymer−NP surface interactions affect these properties.We show that kinetics of infiltration and the properties of PINFs have nontrivial and at times counterintuitive dependence on the extent of nanoconfinement and the interaction strengths between polymers and NPs.In Section 4,we explore some practical applications of PINFs,demonstrating their multifunctionality in areas such as antireflection coatings and antifouling coatings.We highlight how PINFs with tunable refractive indices serve as effective antireflection coatings and how lubricant depletion-resistant slippery liquid-infused porous surfaces can be developed.In Section 5,we discuss the remaining challenges associated with capillarity-driven techniques and PINFs that need to be addressed and explore potential applications such as functional films,coatings,and membranes for sustainable development.
文摘Glioblastomas belong to the most aggressive human cancers with short survival times.Due to the blood-brainbarrier,they are mostly inaccessible to traditional chemotherapy.We have recently shown that doxorubicin boundto polysorbate-coated nanoparticles crossed the intact blood-brain barrier,thus reaching therapeutic concentra-tions in the brain.Here,we investigated the therapeutic potential of this formulation of doxorubicin in vivo using ananimal model created by implantation of 101/8 glioblastoma tumor in rat brains.Groups of 5-8 glioblastoma-
基金financially supported by the National Key Research and Development Program of China(No.2021YFB4000604)National Natural Science Foundation of China(No.52271220)+2 种基金The Program of the Ministry of Education of China for Introducing Talents of Discipline to Universities(No.B12015)the Fundamental Research Funds for the Central UniversitiesHaihe Laboratory of Sustainable Chemical Transformations,Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials,Science Research and Technology Development Project of Guilin(No.20210102-4)
文摘Electrochemical nitrate(NO_(3)^(-))reduction reaction(eNO_(3)RR)to ammonia(NH3)provides a promising route for both water conservation and green ammonia synthesis.Although various catalysts were designed for the eNO_(3)RR and great achievements have been achieved,it is still a challenge to realize selective eNO_(3)RR to NH3at low concentration for the competing hydrogen evolution reaction(HER)and poor mass transfer of NO_(3)^(-).Herein,we designed a tandem catalyst of Pd nanoparticle loaded Cu_(2)O hierarchical nanofiber(Pd-Cu_(2)O)to improve eNO_(3)RR performance at low nitrate concentration.The Pd-Cu_(2)O shows a faraday efficiency(FE)of 95.80%and an ammonia selectivity of 97.34%at a comparatively low applied potential of-0.15 V versus RHE with low concentration.Besides,it exhibits excellent nitrate removal effects,the residual concentration of nitrate-N was only 7.22 ppm at-0.15 V.Electrochemical characterizations indicate that the abundant secondary heterojunction structures and the tandem effects of Pd-Cu_(2)O synergistic ally accelerate the transfer and conversion of NO_(3)^(-)and improve the dynamic of eNO_(3)RR at low concentration.Furthermore,the operando electrochemical impedance spectroscopy(EIS)and density functional theory(DFT)calculations suggested the tandem effects of Pd-Cu_(2)O improved the adsorption of NO_(3)^(-)and*H and thus promoted the dynamics of eNO_(3)RR at low concentration.The findings highlight the tandem effects of Pd-Cu_(2)O and provide an effective strategy for designing electrocatalysts that can be applied to low concentration and low applied potential conditions.
基金the China Scholarship Council of the People’s Republic of China(PhD grant to W.W.),the National Science Center of Poland under the program OPUS(E.C.and S.M.:2019/33/B/ST5/01495)the University of Bordeaux,the Centre National de la Recherche Scientifique(CNRS)and CIC biomaGUNE is gratefully acknowledged.
文摘The Ullmann coupling reaction of aromatic halides is the most challenging C–C coupling reaction.Both MOF-based and MOF-deriffed types of catalysts haffe recently proffided useful nanocatalysts for a ffariety of reactions,but they haffe rarely been compared.Herein,the Ullmann-type aryl iodide homocoupling is effciently catalyzed by gold and palladium nanoparticles(NPs)loaded on ZIF-8 before(ZIF-8-based nanocatalyst:M@ZIF-8)and after calcination(ZIF-8-deriffed catalyst:M@CN).The nanocatalysts M@ZIF-8(M=Pd,Au)are found to be more effcient than the catalysts M@CN.Pd@ZIF-8 exhibits better perform ances than those of Au@ZIF-8 for a series of aryl iodides,but in the case of 4-nitro-iodobenzene,deshy droiodination was obserffed besides the coupling product.Mechanisms are proposed and discussed for both Au(0)and Pd(0)nanocatalysts.
文摘The primary aim of the study was to prepare narrow sized polymeric nanoparticles by implementing few modifications to the conventional nanoprecipitation technique and to evaluate the effect of various process parameters on prepared polymeric nanoparticles.Eudragit E 100 nanoparticles were prepared by modified nanoprecipitation technique and step-by-step optimization was carried out to evaluate the effect of various process parameters such as organic solvent,polymer concentration,percentage of organic solvent,mode of addition of organic solvent in to aqueous phase,volume of aqueous phase,poloxamer 188 concentration,β-cyclodextrin concentration,temperature generated during sonication process,sonication duration,and drug concentration on the particle size,surface area,distribution width and uniformity of the prepared nanoparticles.The optimized process parameters were implemented to fabricate dual drug loaded Eudragit E 100 nanoparticles which were spherical in shape with mean particle size in the range of 118 to 140 nm,polydispersity index in the range of 0.187 to 0.254 and zeta potential in the range of 16.6 to 28.8 mV.Thus developed modified nanoprecipitation method can be used to fabricate narrow sized polymeric nanoparticles.
基金Shenzhen Science and Technology Innovation Committee(Grant No.JCYJ20170817111443306,JCYJ20170412154335393 and KQTD2016022619584022)Southern University of Science and Technology(Grant No.G01296001)+1 种基金Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control(Grant No.2017B030301012)NSFC(No.51802143)。
文摘Semiconductor photocatalysis provides a promising potential solution to the challenging issue of clean energy production.Construction of multijunction systems is an effective strategy to overcome the serious drawbacks of fast charge recombination and the limited visible-light absorption of semiconductor photocatalysts.Here,we report a novel quaternary heterogeneous photocatalyst fabricated by loading Ag nanoparticles onto ZnO nanowires and subsequent simultaneous formation of core/shell structured ZnO@ZnS and Ag@Ag_(2)S heterojunctions via a one-step anion-exchange sulfuration reaction process.The resulting four-component ZnO@ZnS/Ag@Ag_(2)S multijunction photocatalyst exhibits a high hydrogen evolution activity(140.3μmol g^(-1))under simulated solar light irradiation in 5 h,far exceeding those of bare ZnO(30.8μmol g^(-1)),ZnO@ZnS(92.8μmol g^(-1))and ZnO/Ag(45.1μmol g^(-1))counterparts.The enhanced photocatalytic activity can be attributed to the synergetic effect of the formation of both Z-scheme and type II core/shell heterojunctions,favoring light absorption and separation of photogenerated electron-hole pairs in the composite.This work provides a facile,controlled method for the fabrication of multicomponent heterostructures used for efficient solar water splitting.
基金support of this work by the 973 program(2012CB821705)NSFC(21221001,21203196,21425102)CAS(XDA07070200).
文摘Two low-dimensional Cu(I)boron imidazolate frameworks(BIFs),[CuBH(bim)_(3)]_(n)(BIF-40;bim=benzimidazolate)and[CuBH(im)_(3)]_(n)(BIF-6,im=imidazolate),have been synthesized and both of them display unique mechanochromism.In addition,BIF-40 showed reducing activity due to the rich B–H bonds in the structure,and it was employed to load AuPd bimetal nanoparticles through a one-step process for further catalysis.The corresponding mechanism involving a grinding process between chains or layers is discussed in detail.This work not only provides compelling evidence for designing and applying coordination polymers as mechanochromic materials,but also develops an eco-friendly strategy for loading bimetallic NPs into BIFs.
