Triboelectric nanogenerators(TENGs)are advanced devices designed to harness mechanical energy from various sources such as vibrations,friction,or shear and convert it into electrical energy.Schottkybased tribovoltaic ...Triboelectric nanogenerators(TENGs)are advanced devices designed to harness mechanical energy from various sources such as vibrations,friction,or shear and convert it into electrical energy.Schottkybased tribovoltaic nanogenerators(TVNGs)are a type of TENG that incorporates a semiconductor-metal barrier,known as a Schottky barrier,into their design.This barrier aids in rectifying the generated electrical output,eliminating the need for external current rectification circuits.Further,silicon-based Schottky TVNGs can leverage existing surface functionalization procedures to improve device output and durability.Almost without exception,these procedures commence with an oxide-free and hydrogen-terminated silicon surface(Si-H).Replacing hydrogen with its heavier isotope deuterium(Si-D)does not hinder access to established surface chemistry procedures,and based on previous reports the isotope exchange is likely to improve resistance of the non-oxide semiconductor against its anodic decomposition.In this report we have developed the optimal surface chemistry procedures for preparing Si-D surfaces and explored to what extent this isotope effect translates into improved performances and durability of Schottky TVNGs.Our findings reveal that the maximum current output of TVNGs constructed on Si-D Si(111)crystals is comparable to that of mainstream Si-H devices.Additionally,we highlight a generally higher density of surface electrical defects in Si-D compared to Si-H,and verify the contribution of a flexoelectric term to the mechanic-to-electrical energy conversion mechanism.Ultimately,our experiments demonstrate that the primary advantage of replacing hydrogen with deuterium lies in enhancing device longevity.展开更多
Functional multiblock poly(ether-b-amide)(PEBA)copolymers,comprised of PA1212(polyamide 1212)as hard segments and Jeffamine ED-2003 as soft segments,were successfully prepared via two-step melt polycondensation withou...Functional multiblock poly(ether-b-amide)(PEBA)copolymers,comprised of PA1212(polyamide 1212)as hard segments and Jeffamine ED-2003 as soft segments,were successfully prepared via two-step melt polycondensation without any amidation catalyst.Here,using diamino-terminated poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide)(PPO-PEO-PPO),Jeffamine ED-2003,enhances the compatibility between polyamide oligomer and polyether,which is better than the traditional route using hydroxyl-terminated polyether.The chemical structure of multiblock PEBAs,as well as the microphase separated structure with crystalline phase of polyamide and polyether,were confirmed by heteronuclear multiple-bond correlation spectrum,heteronuclear multiple quantum correlation spectrum,Fourier transform infrared spectroscopy(FT-IR),differential scanning calorimetry and dynamic mechanical analysis.The hydrophilic PEBA copolymers showed water adsorption ranging from 87.3%to 17.1%depending on the polyether content,and specially showed moisture responsive behavior within seconds when exposed to moisture.The corresponding mechanism was studied using time-resolved attenuated total reflectance FT-IR spectroscopy in the molecular level and the water diffusion coefficient was estimated to be 1.07×10^(–8)cm^(2)∙s^(-1).Two-dimensional correlation FT-IR spectra analysis was performed to confirm that the interaction between water and polyether phase was in preference to that between water and polyamide matrix,and water molecule only forms hydrogen bond with the polyether segment.Due to the incorporation of PEO segments,the PEBAs have the surface resistivity varying from 5.6×10^(9)to 6.5×10^(10)Ω,which makes PEBA potential candidate as permanent antistatic agent.展开更多
Centrifugal and shear forces are produced when solids or liquids rotate.Rotary systems and devices that use these forces,such as dynamic thin-film flow technology,are evolving continuously,improve material structure-p...Centrifugal and shear forces are produced when solids or liquids rotate.Rotary systems and devices that use these forces,such as dynamic thin-film flow technology,are evolving continuously,improve material structure-property relationships at the nanoscale,representing a rapidly thriving and expanding field of research high with green chemistry metrics,consolidated at the inception of science.The vortex fluidic device(VFD)provides many advantages over conventional batch processing,with fluidic waves causing high shear and producing large surface areas for micro-mixing as well as rapid mass and heat transfer,enabling reactions beyond diffusion control.Combining these abilities allows for a green and innovative approach to altering materials for various research and industry applications by controlling small-scale flows and regulating molecular and macromolecular chemical reactivity,self-organization phenomena,and the synthesis of novel materials.This review highlights the aptitude of the VFD as clean technology,with an increase in efficiency for a diversity of top-down,bottom-up,and novel material transformations which benefit from effective vortex-based processing to control material structure-property relationships.展开更多
Antireflection layers are commonly used in photovoltaics to increase light absorption and therefore increase maximum photocurrent.Here,pyramid structures are created on Si surfaces with alkaline solution etching.The e...Antireflection layers are commonly used in photovoltaics to increase light absorption and therefore increase maximum photocurrent.Here,pyramid structures are created on Si surfaces with alkaline solution etching.The extent of pyramid coverage depends directly on the reaction time and as a result,the surface reflectance decreases with reaction time.展开更多
基金Simone Ciampi and Melanie Macgregor acknowledge support from the Australian Research Council(Grant Nos.DP220100553,FT190100148,and FT200100301)the instruments and expertise of Microscopy Australia at the Future Industries Institute,University of South Australia,enabled by NCRIS,university,and state government support.
文摘Triboelectric nanogenerators(TENGs)are advanced devices designed to harness mechanical energy from various sources such as vibrations,friction,or shear and convert it into electrical energy.Schottkybased tribovoltaic nanogenerators(TVNGs)are a type of TENG that incorporates a semiconductor-metal barrier,known as a Schottky barrier,into their design.This barrier aids in rectifying the generated electrical output,eliminating the need for external current rectification circuits.Further,silicon-based Schottky TVNGs can leverage existing surface functionalization procedures to improve device output and durability.Almost without exception,these procedures commence with an oxide-free and hydrogen-terminated silicon surface(Si-H).Replacing hydrogen with its heavier isotope deuterium(Si-D)does not hinder access to established surface chemistry procedures,and based on previous reports the isotope exchange is likely to improve resistance of the non-oxide semiconductor against its anodic decomposition.In this report we have developed the optimal surface chemistry procedures for preparing Si-D surfaces and explored to what extent this isotope effect translates into improved performances and durability of Schottky TVNGs.Our findings reveal that the maximum current output of TVNGs constructed on Si-D Si(111)crystals is comparable to that of mainstream Si-H devices.Additionally,we highlight a generally higher density of surface electrical defects in Si-D compared to Si-H,and verify the contribution of a flexoelectric term to the mechanic-to-electrical energy conversion mechanism.Ultimately,our experiments demonstrate that the primary advantage of replacing hydrogen with deuterium lies in enhancing device longevity.
基金financially supported by the National Natural Science Foundation of China (21978089 and 21878256)the Fundamental Research Funds for the Central Universities (22221818010)+1 种基金the 111 Project (B20031)the Program of Shanghai Subject Chief Scientist (21XD1433000)
文摘Functional multiblock poly(ether-b-amide)(PEBA)copolymers,comprised of PA1212(polyamide 1212)as hard segments and Jeffamine ED-2003 as soft segments,were successfully prepared via two-step melt polycondensation without any amidation catalyst.Here,using diamino-terminated poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide)(PPO-PEO-PPO),Jeffamine ED-2003,enhances the compatibility between polyamide oligomer and polyether,which is better than the traditional route using hydroxyl-terminated polyether.The chemical structure of multiblock PEBAs,as well as the microphase separated structure with crystalline phase of polyamide and polyether,were confirmed by heteronuclear multiple-bond correlation spectrum,heteronuclear multiple quantum correlation spectrum,Fourier transform infrared spectroscopy(FT-IR),differential scanning calorimetry and dynamic mechanical analysis.The hydrophilic PEBA copolymers showed water adsorption ranging from 87.3%to 17.1%depending on the polyether content,and specially showed moisture responsive behavior within seconds when exposed to moisture.The corresponding mechanism was studied using time-resolved attenuated total reflectance FT-IR spectroscopy in the molecular level and the water diffusion coefficient was estimated to be 1.07×10^(–8)cm^(2)∙s^(-1).Two-dimensional correlation FT-IR spectra analysis was performed to confirm that the interaction between water and polyether phase was in preference to that between water and polyamide matrix,and water molecule only forms hydrogen bond with the polyether segment.Due to the incorporation of PEO segments,the PEBAs have the surface resistivity varying from 5.6×10^(9)to 6.5×10^(10)Ω,which makes PEBA potential candidate as permanent antistatic agent.
基金Postgraduate Research Scholarship and Flinders University Research Investment Fund 2022,and the Australian Research Council,Grant/Award Numbers:DP200101105,DP200101106。
文摘Centrifugal and shear forces are produced when solids or liquids rotate.Rotary systems and devices that use these forces,such as dynamic thin-film flow technology,are evolving continuously,improve material structure-property relationships at the nanoscale,representing a rapidly thriving and expanding field of research high with green chemistry metrics,consolidated at the inception of science.The vortex fluidic device(VFD)provides many advantages over conventional batch processing,with fluidic waves causing high shear and producing large surface areas for micro-mixing as well as rapid mass and heat transfer,enabling reactions beyond diffusion control.Combining these abilities allows for a green and innovative approach to altering materials for various research and industry applications by controlling small-scale flows and regulating molecular and macromolecular chemical reactivity,self-organization phenomena,and the synthesis of novel materials.This review highlights the aptitude of the VFD as clean technology,with an increase in efficiency for a diversity of top-down,bottom-up,and novel material transformations which benefit from effective vortex-based processing to control material structure-property relationships.
基金The support of the Australian Research Council Discovery Program(DP150101354 and DP160101301)is gratefully acknowledged.
文摘Antireflection layers are commonly used in photovoltaics to increase light absorption and therefore increase maximum photocurrent.Here,pyramid structures are created on Si surfaces with alkaline solution etching.The extent of pyramid coverage depends directly on the reaction time and as a result,the surface reflectance decreases with reaction time.
