Effective sealing of wet,dynamic and concealed wounds remains a formidable challenge in clinical practice.Sprayable hydrogel sealants are promising due to their ability to cover a wide area rapidly,but they face limit...Effective sealing of wet,dynamic and concealed wounds remains a formidable challenge in clinical practice.Sprayable hydrogel sealants are promising due to their ability to cover a wide area rapidly,but they face limitations in dynamic and moist environments.To address this issue,we have employed the principle of a homogeneous network to design a sprayable hydrogel sealant with enhanced fatigue resistance and reduced swelling.This network is formed by combining the spherical structure of lysozyme(LZM)with the orthotetrahedral structure of 4-arm-polyethylene glycol(4-arm-PEG).We have achieved exceptional sprayability by controlling the pH of the precursor solution.The homogeneous network,constructed through uniform cross-linking of amino groups in protein and 4-arm-PEG-NHS,provides the hydrogel with outstanding fatigue resistance,low swelling and sustained adhesion.In vitro testing demonstrated that it could endure 2000 cycles of underwater shearing,while in vivo experiments showed adhesion maintenance exceeding 24 h.Furthermore,the hydrogel excelled in sealing leaks and promoting ulcer healing in models including porcine cardiac hemorrhage,lung air leakage and rat oral ulcers,surpassing commonly used clinical materials.Therefore,our research presents an advanced biomaterial strategy with the potential to advance the clinical management of wet,dynamic and concealed wounds.展开更多
The bamboo fiber functionalized with phthalic anhydride underwent carbonization,yielding bam-boo cellulose-derived carbon nanomaterials(C-BCN).These C-BCN were subsequently integrated into an acrylamide precursor solu...The bamboo fiber functionalized with phthalic anhydride underwent carbonization,yielding bam-boo cellulose-derived carbon nanomaterials(C-BCN).These C-BCN were subsequently integrated into an acrylamide precursor solution to synthesize an ultra-robust,fatigue-resistant conductive hydrogel(PAM-C-BCN).During in situ polymerization,the abundant active sites on the C-BCN surface facilitated covalent cross-linking with the polyacrylamide(PAM)matrix.This interfacial interaction promoted strong adhesion between the PAM chains and the carbon nanostructures,forming a densely interpenetrated network through macromolecular entanglement.The synergis-tic coupling of the rigid C-BCN framework with the flexible polymer chains conferred exceptional mechanical resilience and energy dissipation capabilities to the composite hydrogel.Compared to the PAM hydrogel,the PAM-C-BCN hydrogel exhibited an improvement in mechanical prop-erties,with a fracture strength of 363 kPa(a 2.5%increase),an elongation of approximately 2254%(a 2.0%increase),a fracture energy of 30 kJ/m^(2)(a 3.1%increase),and a toughness of 3.04 MJ/m^(3)(a 4.1%increase).Moreover,PAM-C-BCN hydrogel demonstrated high adhesion(up to 7.5 kPa on pigskin)and conductivity(0.21 S/m).This strategy required neither complex design nor processing,offering a simple and efficient approach with great potential for hydrogel appli-cations requiring high mechanical performance.At the crack tip of PAM-C-BCN hydrogel,C-BCN exhibited superior crack propagation resistance compared to SiO2 nanoparticles.Importantly,this strategy offered valuable insights for developing tough and stretchable hydrogels.展开更多
CaBi_(2)Nb_(2)O_(9) thin film capacitors were fabricated on SrRuO_(3)-buffered Pt(111)/Ti/Si(100)substrates by adopting a two-step fabrication process.This process combines a low-temperature sputtering deposition with...CaBi_(2)Nb_(2)O_(9) thin film capacitors were fabricated on SrRuO_(3)-buffered Pt(111)/Ti/Si(100)substrates by adopting a two-step fabrication process.This process combines a low-temperature sputtering deposition with a rapid thermal annealing(RTA)to inhibit the grain growth,for the purposes of delaying the polarization saturation and reducing the ferroelectric hysteresis.By using this method,CaBi_(2)Nb_(2)O_(9) thin films with uniformly distributed nanograins were obtained,which display a large recyclable energy density Wrec≈69 J/cm^(3) and a high energy efficiencyη≈82.4%.A superior fatigue-resistance(negligible energy performance degradation after 10^(9) charge-discharge cycles)and a good thermal stability(from-170 to 150℃)have also been achieved.This two-step method can be used to prepare other bismuth layer-structured ferroelectric film capacitors with enhanced energy storage performances.展开更多
Particle-based electrocatalysts need to be glued on an electrode,where fast and slow steps of the reaction are spatially and temporally convoluted near the particles.Since the particles are under continuous electroche...Particle-based electrocatalysts need to be glued on an electrode,where fast and slow steps of the reaction are spatially and temporally convoluted near the particles.Since the particles are under continuous electrochemical stress,decay in their catalytic performance(a.k.a.,fatigue)often occurs due to degradation of the active materials,detachment of particles and deteriorating kinetics.Here we report that these problems are well addressed by fluidizing the particles.The catalysts,instead of being fixed on an electrode,are now fluidized in the electrolyte.Reaction occurs when individual particles collide with the electrode,which collectively delivers a continuous,scalable and stable electrochemical current.Since the catalysts now work in rotation,they experience much faster kinetics and avoid the buildup of excessive electrochemical stress,leading to orders of magnitude higher particle-average efficiency and greatly enhanced fatigue resistance.Proof-ofconcepts are demonstrated using Pt/C catalysts for three well-known reactions,including oxygen evolution,hydrogen evolution and methanol oxidation reactions,all of which suffer severe performance decay using Pt/C under different mechanisms.Fluidized electrocatalysis breaks the spatial and temporal continuum of electrocatalytic reactions,and makes them drastically more fatigue resistant.It is material-and reaction-agnostic,and should be a general approach to enhance electrocatalytic reactions.展开更多
基金supported by the National key research and development program(2021YFB3800800)the National Natural Science Foundation of China(31922041,11932012,32171341,82202334)+2 种基金the 111 Project(B14018)Excellence Project of Shanghai Municipal Health Commission(20234Z0003)the Science and Technology Innovation Project and Excellent Academic Leader Project of Shanghai Science and Technology Committee(21S31901500,21XD1421100)are acknowledged.
文摘Effective sealing of wet,dynamic and concealed wounds remains a formidable challenge in clinical practice.Sprayable hydrogel sealants are promising due to their ability to cover a wide area rapidly,but they face limitations in dynamic and moist environments.To address this issue,we have employed the principle of a homogeneous network to design a sprayable hydrogel sealant with enhanced fatigue resistance and reduced swelling.This network is formed by combining the spherical structure of lysozyme(LZM)with the orthotetrahedral structure of 4-arm-polyethylene glycol(4-arm-PEG).We have achieved exceptional sprayability by controlling the pH of the precursor solution.The homogeneous network,constructed through uniform cross-linking of amino groups in protein and 4-arm-PEG-NHS,provides the hydrogel with outstanding fatigue resistance,low swelling and sustained adhesion.In vitro testing demonstrated that it could endure 2000 cycles of underwater shearing,while in vivo experiments showed adhesion maintenance exceeding 24 h.Furthermore,the hydrogel excelled in sealing leaks and promoting ulcer healing in models including porcine cardiac hemorrhage,lung air leakage and rat oral ulcers,surpassing commonly used clinical materials.Therefore,our research presents an advanced biomaterial strategy with the potential to advance the clinical management of wet,dynamic and concealed wounds.
基金supported by Applied Basic Research Program of Yunnan Province(No.202301AS070041)National Natural Science Foundation of China(No.32171884)+5 种基金the Major Science and Technology Project of Yunnan Province(202402AE090027)Long Yang acknowledges Candidates of the Young and Middle-Aged Academic Leaders of Yunnan Province(No.202105AC160048)the Ten Thousand Talent Program for Young Topnotch Talents of Yunnan Province(No.YNWR-QNBJ-2020-136)Guanben Du acknowledges the Yunnan Provincial Academician Workstation(No.YSZJGZZ-2020052)the 111 Project(No.D21027)supported by the Scientific Research Fund project of Education Department of Yunnan Province(No.2025J0626).
文摘The bamboo fiber functionalized with phthalic anhydride underwent carbonization,yielding bam-boo cellulose-derived carbon nanomaterials(C-BCN).These C-BCN were subsequently integrated into an acrylamide precursor solution to synthesize an ultra-robust,fatigue-resistant conductive hydrogel(PAM-C-BCN).During in situ polymerization,the abundant active sites on the C-BCN surface facilitated covalent cross-linking with the polyacrylamide(PAM)matrix.This interfacial interaction promoted strong adhesion between the PAM chains and the carbon nanostructures,forming a densely interpenetrated network through macromolecular entanglement.The synergis-tic coupling of the rigid C-BCN framework with the flexible polymer chains conferred exceptional mechanical resilience and energy dissipation capabilities to the composite hydrogel.Compared to the PAM hydrogel,the PAM-C-BCN hydrogel exhibited an improvement in mechanical prop-erties,with a fracture strength of 363 kPa(a 2.5%increase),an elongation of approximately 2254%(a 2.0%increase),a fracture energy of 30 kJ/m^(2)(a 3.1%increase),and a toughness of 3.04 MJ/m^(3)(a 4.1%increase).Moreover,PAM-C-BCN hydrogel demonstrated high adhesion(up to 7.5 kPa on pigskin)and conductivity(0.21 S/m).This strategy required neither complex design nor processing,offering a simple and efficient approach with great potential for hydrogel appli-cations requiring high mechanical performance.At the crack tip of PAM-C-BCN hydrogel,C-BCN exhibited superior crack propagation resistance compared to SiO2 nanoparticles.Importantly,this strategy offered valuable insights for developing tough and stretchable hydrogels.
基金the financial support of the National Natural Science Foundation of China(Grant Nos.51772175 and 51872166)the Nano Projects of Suzhou City(Grant No.ZXG201445)+2 种基金the support from the Seed Funding for Top Talents in Qilu University of Technology(Shandong Academy of Sciences)the International Cooperation Research Project of Qilu University of Technology(Grant No.QLUTGJHZ2018003)the Independent Innovation Foundation of Shandong University(Grant Nos.2018JC045 and 2017ZD008).
文摘CaBi_(2)Nb_(2)O_(9) thin film capacitors were fabricated on SrRuO_(3)-buffered Pt(111)/Ti/Si(100)substrates by adopting a two-step fabrication process.This process combines a low-temperature sputtering deposition with a rapid thermal annealing(RTA)to inhibit the grain growth,for the purposes of delaying the polarization saturation and reducing the ferroelectric hysteresis.By using this method,CaBi_(2)Nb_(2)O_(9) thin films with uniformly distributed nanograins were obtained,which display a large recyclable energy density Wrec≈69 J/cm^(3) and a high energy efficiencyη≈82.4%.A superior fatigue-resistance(negligible energy performance degradation after 10^(9) charge-discharge cycles)and a good thermal stability(from-170 to 150℃)have also been achieved.This two-step method can be used to prepare other bismuth layer-structured ferroelectric film capacitors with enhanced energy storage performances.
基金Y.Z.and Y.K.thanks University of Electronic Science and Technology of China(UESTC)for supporting their academic visit and research activities at Northwestern that generated most data reported in this work.Y.Z.also thanks her new faculty startup fund at Hunan University,which supported her to reproduce the work and generate some new data during the review of the manuscript.J.H.thanks the support from the Robert R.McCormick School of Engineering and Applied Science at Northwestern,and the Humboldt Research Award,an earlier Guggenheim Fellowship and an earlier gift fund from the Sony Corporation,which offered the intellectual freedom for him to indulge in new and unfunded research ideas during his academic leaves and conceptualize this work.This work made use of the TEM facility of Northwestern University’s NUANCE Center,which has received support from the Soft and Hybrid Nanotechnology Experimental(SHyNE)Resource(NSF ECCS-1542205)the MRSEC program(NSF DMR-1720139)at the Materials Research Center,the International Institute for Nanotechnology(IIN),the Keck Foundation,and the State of Illinois,through the IIN.The authors thank Luke Prestowitz,Alane Lim,Kevin Chiou,Prof.Markus Antonietti from Max Planck Institute of Colloids and Interfaces for helpful discussions.We also thank the anonymous reviewers for their helpful comments and suggestions.
文摘Particle-based electrocatalysts need to be glued on an electrode,where fast and slow steps of the reaction are spatially and temporally convoluted near the particles.Since the particles are under continuous electrochemical stress,decay in their catalytic performance(a.k.a.,fatigue)often occurs due to degradation of the active materials,detachment of particles and deteriorating kinetics.Here we report that these problems are well addressed by fluidizing the particles.The catalysts,instead of being fixed on an electrode,are now fluidized in the electrolyte.Reaction occurs when individual particles collide with the electrode,which collectively delivers a continuous,scalable and stable electrochemical current.Since the catalysts now work in rotation,they experience much faster kinetics and avoid the buildup of excessive electrochemical stress,leading to orders of magnitude higher particle-average efficiency and greatly enhanced fatigue resistance.Proof-ofconcepts are demonstrated using Pt/C catalysts for three well-known reactions,including oxygen evolution,hydrogen evolution and methanol oxidation reactions,all of which suffer severe performance decay using Pt/C under different mechanisms.Fluidized electrocatalysis breaks the spatial and temporal continuum of electrocatalytic reactions,and makes them drastically more fatigue resistant.It is material-and reaction-agnostic,and should be a general approach to enhance electrocatalytic reactions.
