The self-driven behavior of droplets on a functionalized surface,coupled with wetting gradient and wedge patterns,is systematically investigated using molecular dynamics(MD)simulations.The effects of key factors,inclu...The self-driven behavior of droplets on a functionalized surface,coupled with wetting gradient and wedge patterns,is systematically investigated using molecular dynamics(MD)simulations.The effects of key factors,including wedge angle,wettability,and wetting gradient,on the droplet self-driving effect is revealed from the nanoscale.Results indicate that the maximum velocity of droplets on hydrophobic wedge-shaped surfaces increases with the wedge angle,accompanied by a rapid attenuation of driving force;however,the average velocity decreases with the increased wedge angle.Conversely,droplet movement on hydrophilic wedge-shaped surfaces follows the opposite trend,particularly in terms of average velocity compared to the hydrophobic case.Both wedge-shaped and composite gradient wedge-shaped surfaces are found to induce droplet motion,with droplets exhibiting higher speeds and distances on hydrophobic surfaces compared to hydrophilic surfaces,regardless of surface type.Importantly,the inclusion of wettability gradients significantly influences droplet motion,with hydrophobic composite gradient wedge-shaped surfaces showing considerable improvements in droplet speed and distance compared to their hydrophilic counterparts.By combining suitable wettability gradients with wedge-shaped surfaces,the limitations inherent in the wettability gradient range and wedge-shaped configuration can be mitigated,thereby enhancing droplet speed and distance.The findings presented in this paper offer valuable insights for the design of advanced functional surfaces tailored for manipulating droplets in real-world applications.展开更多
To investigate the microscopicmechanism underlying the influence of surface-chemical gradient on heat andmass recovery,a molecular dynamicsmodel including droplet condensation and transport process has been developed ...To investigate the microscopicmechanism underlying the influence of surface-chemical gradient on heat andmass recovery,a molecular dynamicsmodel including droplet condensation and transport process has been developed to examine heat and mass recovery performance.This work aimed at identify optimal conditions for enhancing heat and mass recovery through the combination of wettability gradient and nanopore transport.For comprehensive analysis,the structure in the simulation was categorized into three distinct groups:a homogeneous structure,a small wettability gradient,and a large wettability gradient.The homogeneous surface demonstrated low efficiency in heat and mass transfer,as evidenced by filmwise condensation.In contrast,the surface with a small wettability gradient experienced a transition from dropwise condensation to filmwise condensation,resulting in a gradual decrease in the efficiency of vapor heat and mass transfer.Only a large wettability gradient could achieve periodic and efficient dropwise condensation heat and mass transfer which was attributed to the rapid droplet coalescence and transport to the nanopore after condensing on the cold surface.展开更多
Multi-layered functionally graded(FG)structure Ni-W/Er2O3 nanocomposite films were prepared by continuously changing the deposition parameters,in which the Er2O3 and W contents varied with thickness.The microstructure...Multi-layered functionally graded(FG)structure Ni-W/Er2O3 nanocomposite films were prepared by continuously changing the deposition parameters,in which the Er2O3 and W contents varied with thickness.The microstructure and chemical composition of the electrodeposited Ni-W/Er2O3 films were determined by scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDS).The anti-corrosion and wear properties of the electrodeposition films were investigated by electrochemical measurement and ball-on-disk friction test.The microhardness distribution of the cross section of nanocomposites was measured by nanoindentation.The results showed that with decreasing agitation rate or increasing average current density,the contents of Er2O3 nanoparticles and tungsten were distributed in a gradient along the thickness,and the contents on the surface were larger.By comparison,FG Ni-W/Er2O3 films had better anti-corrosion and wear properties than the uniform Ni-W/Er2O3 films.Atomic force microscopy(AFM)and profilometry measurements indicated that Er2O3 nanoparticles had an effect on the surface roughness.展开更多
The global organ shortage is critically severe,withmany patients at risk of lifethreatening conditions due to the scarcity of suitable donor organs.Gene-edited porcine organs for human transplantation have emerged as ...The global organ shortage is critically severe,withmany patients at risk of lifethreatening conditions due to the scarcity of suitable donor organs.Gene-edited porcine organs for human transplantation have emerged as a promising solution and a focus of scientific research.We urge all relevant parties in China to collaborate in establishing consensus and standards for xenotransplantation using genetically modified pigs to benefit patients worldwide.展开更多
Thermosensitive hydrogel can integrate vapor molecular capture,in-situ liquefaction,and thermal-induced water release for freshwater capture.This study aimed to examine the dynamic behavior of poly(N-isopropylacrylami...Thermosensitive hydrogel can integrate vapor molecular capture,in-situ liquefaction,and thermal-induced water release for freshwater capture.This study aimed to examine the dynamic behavior of poly(N-isopropylacrylamide)(PNIPAM)single chain and cross-linking thermosensitive hydrogel through molecular dynamics simulation.Specifically,the impact of lower critical solution temperature(LCST)on the conformation of polymer chain and the interaction between water and polymer chain were also investigated.The polymer chain conformation underwent a transition from coil to globule when the temperature exceeded the LCST,indicating the temperature responsiveness of PNIPAM.Additionally,thermosensitive hydrogel samples with different cross-linking degrees(DOC)were studied,and relevant parameters such as the number of free water,the diffusion coefficient of water,and the pore size distribution were counted to evaluate the temperature responsiveness and water release characteristics of thermosensitive hydrogel.展开更多
基金supported by the National Natural Science Foundation of China(No.52206073)the University Outstanding Youth Fund Project of Anhui Province(Nos.2022AH020028 and 2022AH030037)+2 种基金the Natural Science Foundation of Anhui Province(Nos.1908085QF292 and 2308085ME173)Anhui Province Outstanding Young Talents Support Program(No.gxyqZD2022058)Guangdong Basic and Applied Basic Research Foundation(Nos.2024A1515011379 and 2023A1515110613).
文摘The self-driven behavior of droplets on a functionalized surface,coupled with wetting gradient and wedge patterns,is systematically investigated using molecular dynamics(MD)simulations.The effects of key factors,including wedge angle,wettability,and wetting gradient,on the droplet self-driving effect is revealed from the nanoscale.Results indicate that the maximum velocity of droplets on hydrophobic wedge-shaped surfaces increases with the wedge angle,accompanied by a rapid attenuation of driving force;however,the average velocity decreases with the increased wedge angle.Conversely,droplet movement on hydrophilic wedge-shaped surfaces follows the opposite trend,particularly in terms of average velocity compared to the hydrophobic case.Both wedge-shaped and composite gradient wedge-shaped surfaces are found to induce droplet motion,with droplets exhibiting higher speeds and distances on hydrophobic surfaces compared to hydrophilic surfaces,regardless of surface type.Importantly,the inclusion of wettability gradients significantly influences droplet motion,with hydrophobic composite gradient wedge-shaped surfaces showing considerable improvements in droplet speed and distance compared to their hydrophilic counterparts.By combining suitable wettability gradients with wedge-shaped surfaces,the limitations inherent in the wettability gradient range and wedge-shaped configuration can be mitigated,thereby enhancing droplet speed and distance.The findings presented in this paper offer valuable insights for the design of advanced functional surfaces tailored for manipulating droplets in real-world applications.
基金supported by the National Natural Science Foundation of China(No.52206093)the University Outstanding Youth Fund Project of Anhui Province(Nos.2022AH020028 and 2022AH030037)+2 种基金the Natural Science Foundation of Anhui Province(Nos.1908085QF292 and 2308085ME173)Anhui Province Outstanding Young Talents Support Program(No.gxyqZD2022058)Guangdong Basic and Applied Basic Research Foundation(Nos.2024A1515011379 and 2023A1515110613).
文摘To investigate the microscopicmechanism underlying the influence of surface-chemical gradient on heat andmass recovery,a molecular dynamicsmodel including droplet condensation and transport process has been developed to examine heat and mass recovery performance.This work aimed at identify optimal conditions for enhancing heat and mass recovery through the combination of wettability gradient and nanopore transport.For comprehensive analysis,the structure in the simulation was categorized into three distinct groups:a homogeneous structure,a small wettability gradient,and a large wettability gradient.The homogeneous surface demonstrated low efficiency in heat and mass transfer,as evidenced by filmwise condensation.In contrast,the surface with a small wettability gradient experienced a transition from dropwise condensation to filmwise condensation,resulting in a gradual decrease in the efficiency of vapor heat and mass transfer.Only a large wettability gradient could achieve periodic and efficient dropwise condensation heat and mass transfer which was attributed to the rapid droplet coalescence and transport to the nanopore after condensing on the cold surface.
基金the National Natural Science Foundation of China(Nos.51625504,51675421,51427805,51435002,91748209,51705406,and91748209)the Joint fund of the Ministry of Education of China(Nos.6141A0231 and 6141A0202)partially sponsored by National Key R&D Program of China(Nos.2016YFF0100700 and 2017YFF0204803)。
文摘Multi-layered functionally graded(FG)structure Ni-W/Er2O3 nanocomposite films were prepared by continuously changing the deposition parameters,in which the Er2O3 and W contents varied with thickness.The microstructure and chemical composition of the electrodeposited Ni-W/Er2O3 films were determined by scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDS).The anti-corrosion and wear properties of the electrodeposition films were investigated by electrochemical measurement and ball-on-disk friction test.The microhardness distribution of the cross section of nanocomposites was measured by nanoindentation.The results showed that with decreasing agitation rate or increasing average current density,the contents of Er2O3 nanoparticles and tungsten were distributed in a gradient along the thickness,and the contents on the surface were larger.By comparison,FG Ni-W/Er2O3 films had better anti-corrosion and wear properties than the uniform Ni-W/Er2O3 films.Atomic force microscopy(AFM)and profilometry measurements indicated that Er2O3 nanoparticles had an effect on the surface roughness.
基金supported by The Key Project of Zhejiang Provincial Natural Science Foundation of China(LZ22C010003)the Scientific and Technological Innovation Leading Talents Project of Zhejiang Provincial“High-level Talents Special Support Plan”(2021R52043).
文摘The global organ shortage is critically severe,withmany patients at risk of lifethreatening conditions due to the scarcity of suitable donor organs.Gene-edited porcine organs for human transplantation have emerged as a promising solution and a focus of scientific research.We urge all relevant parties in China to collaborate in establishing consensus and standards for xenotransplantation using genetically modified pigs to benefit patients worldwide.
基金supported by National Natural Science Foundation of China(No.52206073)Fundamental Research Funds for the Central Universities(No.3132023119)Guangdong Basic and Applied Basic Research Foundation(Nos.2024A1515011379 and 2023A1515110613).
文摘Thermosensitive hydrogel can integrate vapor molecular capture,in-situ liquefaction,and thermal-induced water release for freshwater capture.This study aimed to examine the dynamic behavior of poly(N-isopropylacrylamide)(PNIPAM)single chain and cross-linking thermosensitive hydrogel through molecular dynamics simulation.Specifically,the impact of lower critical solution temperature(LCST)on the conformation of polymer chain and the interaction between water and polymer chain were also investigated.The polymer chain conformation underwent a transition from coil to globule when the temperature exceeded the LCST,indicating the temperature responsiveness of PNIPAM.Additionally,thermosensitive hydrogel samples with different cross-linking degrees(DOC)were studied,and relevant parameters such as the number of free water,the diffusion coefficient of water,and the pore size distribution were counted to evaluate the temperature responsiveness and water release characteristics of thermosensitive hydrogel.
