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.