In the present review,the formation of superhydrophobic(SHP)structures on the surface of Mg alloys was investigated.Different methods including hydrothermal technique,chemical and electrochemical deposition,conversion...In the present review,the formation of superhydrophobic(SHP)structures on the surface of Mg alloys was investigated.Different methods including hydrothermal technique,chemical and electrochemical deposition,conversion and polymer coating,and etching routes were discussed.The superhydrophobicity could form on the surface of Mg alloys by the application of different chemical,electrochemical,and physical methods followed by the immersion of these alloys in the solution containing modifying agents including fatty acids or long-chain molecules.The formed morphology,composition,and contact angle were reported and the effect of synthesis route on these characteristics was reviewed.展开更多
Lithium niobate(LN)has experienced significant developments during past decades due to its versatile properties,especially its large electro-optic(EO)coefficient.For example,bulk LN-based modulators with high speeds a...Lithium niobate(LN)has experienced significant developments during past decades due to its versatile properties,especially its large electro-optic(EO)coefficient.For example,bulk LN-based modulators with high speeds and a superior linearity are widely used in typical fiber-optic communication systems.However,with everincreasing demands for signal transmission capacity,the high power and large size of bulk LN-based devices pose great challenges,especially when one of its counterparts,integrated silicon photonics,has experienced dramatic developments in recent decades.Not long ago,high-quality thin-film LN on insulator(LNOI)became commercially available,which has paved the way for integrated LN photonics and opened a hot research area of LN photonics devices.LNOI allows a large refractive index contrast,thus light can be confined within a more compact structure.Together with other properties of LN,such as nonlinear/acousto-optic/pyroelectric effects,various kinds of high-performance integrated LN devices can be demonstrated.A comprehensive summary of advances in LN photonics is provided.As LN photonics has experienced several decades of development,our review includes some of the typical bulk LN devices as well as recently developed thin film LN devices.In this way,readers may be inspired by a complete picture of the evolution of this technology.We first introduce the basic material properties of LN and several key processing technologies for fabricating photonics devices.After that,various kinds of functional devices based on different effects are summarized.Finally,we give a short summary and perspective of LN photonics.We hope this review can give readers more insight into recent advances in LN photonics and contribute to the further development of LN related research.展开更多
Direct exposure of samples to the active species of air generated by a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has been used to etch and to increase the surface energy of metallic surfaces, photoresist, ...Direct exposure of samples to the active species of air generated by a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has been used to etch and to increase the surface energy of metallic surfaces, photoresist, polymer films, and nonwoven fab- rics. The OAUGDP is a non-thermal plasma with the classical characteristics of a DC normal glow discharge that operates in air (and other gases) at atmospheric pres- sure. Neither a vacuum system nor batch processing is necessary. A wide range of applications to metals, photoresist, films, fabrics, and polymeric webs can be accom- modated by direct exposure of the workpiece to the plasma in parallel-plate reactors. This technolopy is simple, it produces effects that can be obtained in no other way at one atmosphere; it generates minimal pollutants or unwanted by-products; and it is suitable for individual sample or online treatment of metallic surfaces, wafers, films, and fabrics. Early exposures of solid materials to the OAUGDP required minutes to produce rela- tively small increases of surface energy. These durations appeared too long for com- mercial application to fast-moving webs. Recent improvements in OAUGDP gas com- position, power density, plasma quality, recireulating gas flow, and impedance match- ing of the power supply to the parallel plate plasma reactor have made it possible to raise the surface energy of a variety of polymeric webs (PP, PET PE etc.) to levels of 60 to 70 dynes/cm with one second of exposure. In air plasmas, the high surface ener- gies are not durable, and fall to 50 dynes/cm after periods of weeks to months. Here, we report the exposure of metallic surfaces, photoresist, polymeric films, and nonwo- ven fabrics made of PP and PET to an impedance matched parallel plate OAUGDP for durations ranging from one second to several tens of seconds. Data will be re- ported on the surface energy, wettability, wickability, and aging effect of polymeric films and fabrics as functions of time of exposure, and time after exposure; the rate and uniform展开更多
This paper explores the capability of the“surface-protected etching”process for the creation of rattle-type SiO_(2)@void@SiO_(2) colloidal structures featuring a mesoporous silica shell and a mesoporous movable sili...This paper explores the capability of the“surface-protected etching”process for the creation of rattle-type SiO_(2)@void@SiO_(2) colloidal structures featuring a mesoporous silica shell and a mesoporous movable silica core.The surface-protected etching process involves stabilization of the particle surface using a polymer ligand,and then selective etching of the interior to form hollow structures.In this paper,this strategy has been extended to the formation of rattle-like structures by etching SiO_(2)@SiO_(2) core shell particles which are synthesized by a two-step sol gel process.The key is to introduce a protecting polymer of polyvinylpyrrolidone(PVP)to the surface of both core and shell in order to tailor their relative stability against chemical etching.Upon reacting with NaOH,the outer layer silica becomes a hollow shell as only the surface layer is protected by PVP and the interior is removed,while the core remains its original size thanks to the protection of PVP on its surface.This process can be carried out at room temperature without the need of additional templates or complicated heterogeneous coating procedures.The etching process also results in the rattle-type colloids having mesoscale pores with two distinct average sizes.In our demonstration of a model drug delivery process,such mesoporous structures show an interesting two-step elution profile which is believed to be related to the unique porous rattle structures.展开更多
文摘In the present review,the formation of superhydrophobic(SHP)structures on the surface of Mg alloys was investigated.Different methods including hydrothermal technique,chemical and electrochemical deposition,conversion and polymer coating,and etching routes were discussed.The superhydrophobicity could form on the surface of Mg alloys by the application of different chemical,electrochemical,and physical methods followed by the immersion of these alloys in the solution containing modifying agents including fatty acids or long-chain molecules.The formed morphology,composition,and contact angle were reported and the effect of synthesis route on these characteristics was reviewed.
基金the National Research Foundation,Singapore,under its Competitive Research Programme(CRP Award No.NRF-CRP24-2020-0003)This work was also supported by the program for HUST Academic Frontier Youth Team(2018QYTD08)This work was partially supported by A*STAR(Agency for Science,Technology and Research),Singapore,under the RIE2020 Advanced Manufacturing and Engineering(AME)IAF-PP Grant,No.A19B3a0008
文摘Lithium niobate(LN)has experienced significant developments during past decades due to its versatile properties,especially its large electro-optic(EO)coefficient.For example,bulk LN-based modulators with high speeds and a superior linearity are widely used in typical fiber-optic communication systems.However,with everincreasing demands for signal transmission capacity,the high power and large size of bulk LN-based devices pose great challenges,especially when one of its counterparts,integrated silicon photonics,has experienced dramatic developments in recent decades.Not long ago,high-quality thin-film LN on insulator(LNOI)became commercially available,which has paved the way for integrated LN photonics and opened a hot research area of LN photonics devices.LNOI allows a large refractive index contrast,thus light can be confined within a more compact structure.Together with other properties of LN,such as nonlinear/acousto-optic/pyroelectric effects,various kinds of high-performance integrated LN devices can be demonstrated.A comprehensive summary of advances in LN photonics is provided.As LN photonics has experienced several decades of development,our review includes some of the typical bulk LN devices as well as recently developed thin film LN devices.In this way,readers may be inspired by a complete picture of the evolution of this technology.We first introduce the basic material properties of LN and several key processing technologies for fabricating photonics devices.After that,various kinds of functional devices based on different effects are summarized.Finally,we give a short summary and perspective of LN photonics.We hope this review can give readers more insight into recent advances in LN photonics and contribute to the further development of LN related research.
文摘Direct exposure of samples to the active species of air generated by a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has been used to etch and to increase the surface energy of metallic surfaces, photoresist, polymer films, and nonwoven fab- rics. The OAUGDP is a non-thermal plasma with the classical characteristics of a DC normal glow discharge that operates in air (and other gases) at atmospheric pres- sure. Neither a vacuum system nor batch processing is necessary. A wide range of applications to metals, photoresist, films, fabrics, and polymeric webs can be accom- modated by direct exposure of the workpiece to the plasma in parallel-plate reactors. This technolopy is simple, it produces effects that can be obtained in no other way at one atmosphere; it generates minimal pollutants or unwanted by-products; and it is suitable for individual sample or online treatment of metallic surfaces, wafers, films, and fabrics. Early exposures of solid materials to the OAUGDP required minutes to produce rela- tively small increases of surface energy. These durations appeared too long for com- mercial application to fast-moving webs. Recent improvements in OAUGDP gas com- position, power density, plasma quality, recireulating gas flow, and impedance match- ing of the power supply to the parallel plate plasma reactor have made it possible to raise the surface energy of a variety of polymeric webs (PP, PET PE etc.) to levels of 60 to 70 dynes/cm with one second of exposure. In air plasmas, the high surface ener- gies are not durable, and fall to 50 dynes/cm after periods of weeks to months. Here, we report the exposure of metallic surfaces, photoresist, polymeric films, and nonwo- ven fabrics made of PP and PET to an impedance matched parallel plate OAUGDP for durations ranging from one second to several tens of seconds. Data will be re- ported on the surface energy, wettability, wickability, and aging effect of polymeric films and fabrics as functions of time of exposure, and time after exposure; the rate and uniform
文摘This paper explores the capability of the“surface-protected etching”process for the creation of rattle-type SiO_(2)@void@SiO_(2) colloidal structures featuring a mesoporous silica shell and a mesoporous movable silica core.The surface-protected etching process involves stabilization of the particle surface using a polymer ligand,and then selective etching of the interior to form hollow structures.In this paper,this strategy has been extended to the formation of rattle-like structures by etching SiO_(2)@SiO_(2) core shell particles which are synthesized by a two-step sol gel process.The key is to introduce a protecting polymer of polyvinylpyrrolidone(PVP)to the surface of both core and shell in order to tailor their relative stability against chemical etching.Upon reacting with NaOH,the outer layer silica becomes a hollow shell as only the surface layer is protected by PVP and the interior is removed,while the core remains its original size thanks to the protection of PVP on its surface.This process can be carried out at room temperature without the need of additional templates or complicated heterogeneous coating procedures.The etching process also results in the rattle-type colloids having mesoscale pores with two distinct average sizes.In our demonstration of a model drug delivery process,such mesoporous structures show an interesting two-step elution profile which is believed to be related to the unique porous rattle structures.
