The progress of membrane technology with the development of membranes with controlled parameters led to porous membranes.These membranes can be formed using different methods and have numerous applications in science ...The progress of membrane technology with the development of membranes with controlled parameters led to porous membranes.These membranes can be formed using different methods and have numerous applications in science and technology.Anodization of aluminum in this aspect is an electro-synthetic process that changes the surface of the metal through oxidation to deliver an anodic oxide layer.This process results in a self-coordinated,exceptional cluster of round and hollow formed pores with controllable pore widths,periodicity,and thickness.Categorization in barrier type and porous type films,and different methods for the preparation of membranes,have been discussed.After the initial introduction,the paper proceeds with a brief overview of anodizing process.That engages anodic aluminum oxide(AAO)layers to be used as formats in various nanotechnology applications without the necessity for expensive lithographical systems.This review article surveys the current status of the investigation on AAO membranes.A comprehensive analysis is performed on AAO membranes in applications;filtration,sensors,drug delivery,template-assisted growth of various nanostructures.Their multiple usages in nanotechnology have also been discussed to gather nanomaterials and devices or unite theminto specific applications,such as nano-electronic gadgets,channel layers,and clinical platforms tissue designing.From this review,the fact that the specified enhancement of properties of AAO can be done by varying geometric parameters of AAO has been highlighted.No review paper focused on a detailed discussion of multiple applications of AAO with prospects and challenges.Also,it is a challenge for the research community to compare results reported in the literature.This paper provides tables for easy comparison of reported applications with membrane parameters.This review paper represents the formation,properties,applications with objective consideration of the prospects and challenges of AAO applications.The prospects may appeal to researchers to promote the development of unique membranes with functionalization and controlled geometric parameters and check the feasibility of the AAO membranes in nanotechnology and devices.展开更多
This review summarizes the various techniques developed for fabricating nanotube arrays in porous anodic alumina membranes （AAMs）. After a brief introduction to the fabrication process of AAMs, taking carbons, metal...This review summarizes the various techniques developed for fabricating nanotube arrays in porous anodic alumina membranes （AAMs）. After a brief introduction to the fabrication process of AAMs, taking carbons, metals, semiconductors, organics, biomoleculars, and heterojunctions as typical examples, attention will be focused on the recently established methods to fabricate nanotubes in AAM, including electrochemical deposition, surface sol-gel, modified chemical vapor deposition, atomic layer deposition, and layer-by-layer growth. Every method is demonstrated by one or two reported results. Finally, this review is concluded with some perspectives on the research directions and focuses on the AAM-based nanotubes fields.展开更多
The modification procedure of anodic alumina membrane(AAM) was studied. The AAM structure after modification was characterized by nickel nanowires prepared in AAM. Scanning electron microscopy was used to characterize...The modification procedure of anodic alumina membrane(AAM) was studied. The AAM structure after modification was characterized by nickel nanowires prepared in AAM. Scanning electron microscopy was used to characterize the topography and structure properties of the AAM and nickel nanowires. The transformation of the current during the voltage reduction was studied. The mechanism of current and structure change during modification was discussed. The results show that a root structure produces after the AAM modification. The length of the root structure depends on the velocity of the voltage reduction. Slow voltage reduction leads to a large length of the root structure, otherwise, a short length of the root structure. At the end of the modification, the barrier layer is thin enough to be passed by electrons. Hence, the direct electrodeposition of one-dimensional nanowires can be carried out on the AAM with barrier layer and aluminum matrix successfully without any other treatments.展开更多
The pure aluminum and Al Mg Mn alloy were anodized in 4%, 10% and 18.5% phosphoric acid solution, respectively. As for pure Al, the maximum thickness of anodized aluminum oxide (AAO) membrane, 216 nm, is obtained by b...The pure aluminum and Al Mg Mn alloy were anodized in 4%, 10% and 18.5% phosphoric acid solution, respectively. As for pure Al, the maximum thickness of anodized aluminum oxide (AAO) membrane, 216 nm, is obtained by being anodized in 4% solution. Its average pore diameter is around 70 nm, and pore density exceeds 10 10 /cm 2. Under the same technology condition, the membrane thickness decreases with increment of electrolyte content. TEM images show that element Mg or Mn added into aluminum alloy can damage the integration of AAO membrane. During anodizing of aluminum, the formed oxide layer is amorphous. After being annealed at 600 ℃ for 24 h, it is still amorphous. However, when membrane is annealed at 930 ℃, the amorphous oxide begins to transform to γ Al 2O 3 .展开更多
The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates tosynthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pore...The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates tosynthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and thelayer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm themethodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.展开更多
High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed...High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.展开更多
Objective The correlation between various formative conditions and the pore characterizationsof the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic aluminamembrane. M...Objective The correlation between various formative conditions and the pore characterizationsof the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic aluminamembrane. Methods High purity aluminum foils are used as the starting materials. The anodization is conduc-ted in three types of electrolytes, 3% sulfuric acid, 5% sulfuric acid and 2. 7% oxalic acid, respectively, with dif-ferent voltages at for 48h. The characterizations of the pore size, the effective porosity and the pore porosity areobserved and determined by scanning electron microscopy. The hydraulic conductances of the membranes are meas-ured to confirm that the pores are open and evaluate the permselectivity of the membranes. Results The experi-mental result shows that the ordered pore arrays are obtained for oxidation under our experimental conditions. Withthe increasing of the voltage, the pore size and pore porosity increased significantly (P <0.05) , while the effectiveporosity decreased significantly (P <0.05) with the same electrolyte. The pore size formed in 3% sulfuric acid or5% sulfuric acid is much smaller than in 2. 7% oxalic acid as an electrolyte. The hydraulic conductance of anodicalumina membrane that formed under our experimental condition is higher than those of the membranes are availablecurrently used in clinical. Conclusion The results suggest that the optimal conditions for the formation of anodicalumina membrane that used in hemodialysis are in 3% or 5% sulfuric acid with 12. 5V to 17. 5V at for 48h.展开更多
Electrochemical technologies for the on-site treatment of spent acid etchant have received great attention due their ease of operation and economic benefits. On the other hand, a large amount of Cl2 is generated durin...Electrochemical technologies for the on-site treatment of spent acid etchant have received great attention due their ease of operation and economic benefits. On the other hand, a large amount of Cl2 is generated during the electrolysis process, which leads to potential environmental risks. In the present work, a novel threecompartment ceramic membrane flow reactor, including a cathode chamber, an anode chamber, and a gas absorption chamber was developed. The three chambers were divided by an Al2O3 ceramic membrane and a breathable hydrophobic anode diffusion electrode(ADE). The Cl2 evolution onset potential of the ADE was increased to 1.19 V from 1.05 V of the graphite felt, effectively inhibiting the chlorine evolution reaction(CER).The anode-generated Cl2 diffused into the gas absorption chamber through the ADE and was eventually consumed by the H2O2 adsorbent. Cu could be recovered without emitting chlorine due to the special structure of reactor. The current efficiency of copper precipitation and cathode reduction from Cu2+to Cu+reached 97.7%at a working current of 150 m A. These results indicated that the novel membrane reactor had high potential for application in the copper recovery industry.展开更多
Uncontrollable Zn dendrites and side reactions seriously downgrade the cycling stability of the Zn anode,and restrict the commercialization of aqueous zinc ion batteries.Here,PAN-based(PAN,PAN/PMMA)nanofiber membranes...Uncontrollable Zn dendrites and side reactions seriously downgrade the cycling stability of the Zn anode,and restrict the commercialization of aqueous zinc ion batteries.Here,PAN-based(PAN,PAN/PMMA)nanofiber membranes with uniform“zincophilic-hydrophobic”sites have been in-situ electrospun on Zn to effectively prevent harmful side reactions and control Zn plating/stripping behavior.The abundant highly-negative functional groups(C≡N and C=O)of PAN/PMMA have strong coordination interactions with Zn2+,which can accelerate Zn2+desolvation and increase the Zn2+migration number.Furthermore,the even distribution of zincophilic sites can help create a uniform Zn deposition environment and enable horizontal Zn deposition.Simultaneously,the inherent“hydrophobicity”of the nonpolar carbon skeleton in PAN/PMMA can prevent Zn corrosion and hydrogen evolution reaction(HER)side reactions,thus improving the cycling stability of the Zn anode.As a result,PAN/PMMA@Zn symmetric cells demonstrated remarkable rate performance and long cycling stability,sustaining efficient operation for over 2000 cycles at 10 mA cm^(−2)with a low polarization voltage below 65 mV.This Zn anode modification strategy by in-situ constructed PAN-based nanofiber membrane has the advantages of simple-preparation,one-step membrane construction,binder-free,uniform distribution of functionalized units,which not only provides a specific scheme for developing advanced Zn anode but also lays a certain research foundation for developing“separator-anode”integrated Zn-based batteries.展开更多
The porous anodic alumina membranes （PAAMs） have been successfully used as templates for the fabrication of functional nano-materials due to their outstanding regularity and physicochemical properties. In this paper...The porous anodic alumina membranes （PAAMs） have been successfully used as templates for the fabrication of functional nano-materials due to their outstanding regularity and physicochemical properties. In this paper, a transparent double-sided anodic alumina membrane with ultra-thin aluminum substrate was fabricated with the three-step anodic oxidation method in the oxalic acid electrolyte. The characters such as the top-surface morphology, membrane thickness, and depth of nanopores of this three-layer （A1203-A1-A1203） sandwiched nano-structure were controllable through regulating the main anodic oxidation conditions, e.g., anodic oxidation time of various steps, coating remove process. The experiments data revealed that the aluminum substrate is exponential declined with the oxidation time when it was approximately reduced by a few micrometers. This new double-sided anodic alumina membrane can be used as the high-quality functional field emission materials and templates.展开更多
A novel soft polymer template containing a double-layer structure,which includes a thin layer of polymethylmethacrylate(PMMA)used as a pattern layer and a thicker layer of polydimethylsiloxane(PDMS)used as a back laye...A novel soft polymer template containing a double-layer structure,which includes a thin layer of polymethylmethacrylate(PMMA)used as a pattern layer and a thicker layer of polydimethylsiloxane(PDMS)used as a back layer,was fabricated from a replica molding process.Anodic aluminum oxide(AAO)template was used as the replica mold to be replicated to the polymethylmethacrylate layer by a thermal infiltration process under a vacuum condition.Results indicate that PMMA/PDMS soft templates with different sizes could be easily fabricated from the as-prepared AAO replica mold.The PMMA/PDMS soft templates were then employed to imprint a TiO_2 gel for achieving TiO_2 nano-pore arrays.After the imprinting process,the PDMS layer was firstly peeled off and the PMMA layer was then removed into acetonitrile,which can avoid any demolding problems like damages or distortions.The TiO_2 nano-pore arrays with the crystalline of anatase could be obtained at a heat treatment temperature of 450°C.展开更多
文摘The progress of membrane technology with the development of membranes with controlled parameters led to porous membranes.These membranes can be formed using different methods and have numerous applications in science and technology.Anodization of aluminum in this aspect is an electro-synthetic process that changes the surface of the metal through oxidation to deliver an anodic oxide layer.This process results in a self-coordinated,exceptional cluster of round and hollow formed pores with controllable pore widths,periodicity,and thickness.Categorization in barrier type and porous type films,and different methods for the preparation of membranes,have been discussed.After the initial introduction,the paper proceeds with a brief overview of anodizing process.That engages anodic aluminum oxide(AAO)layers to be used as formats in various nanotechnology applications without the necessity for expensive lithographical systems.This review article surveys the current status of the investigation on AAO membranes.A comprehensive analysis is performed on AAO membranes in applications;filtration,sensors,drug delivery,template-assisted growth of various nanostructures.Their multiple usages in nanotechnology have also been discussed to gather nanomaterials and devices or unite theminto specific applications,such as nano-electronic gadgets,channel layers,and clinical platforms tissue designing.From this review,the fact that the specified enhancement of properties of AAO can be done by varying geometric parameters of AAO has been highlighted.No review paper focused on a detailed discussion of multiple applications of AAO with prospects and challenges.Also,it is a challenge for the research community to compare results reported in the literature.This paper provides tables for easy comparison of reported applications with membrane parameters.This review paper represents the formation,properties,applications with objective consideration of the prospects and challenges of AAO applications.The prospects may appeal to researchers to promote the development of unique membranes with functionalization and controlled geometric parameters and check the feasibility of the AAO membranes in nanotechnology and devices.
基金the support provided by the Japan Society for the Promotion of Science(JSPS)Fellowship program at the National Institute of Advanced Industrial Science and Technology,Tsukuba,Japanthe National Natural Science Foundation of China(Grant No.10704074)+1 种基金the Special Project of Excellent Young Researchers of Anhui Province,Chinathe Project of Excellent President Scholarship of Chinese Academy of Sciences.
文摘This review summarizes the various techniques developed for fabricating nanotube arrays in porous anodic alumina membranes （AAMs）. After a brief introduction to the fabrication process of AAMs, taking carbons, metals, semiconductors, organics, biomoleculars, and heterojunctions as typical examples, attention will be focused on the recently established methods to fabricate nanotubes in AAM, including electrochemical deposition, surface sol-gel, modified chemical vapor deposition, atomic layer deposition, and layer-by-layer growth. Every method is demonstrated by one or two reported results. Finally, this review is concluded with some perspectives on the research directions and focuses on the AAM-based nanotubes fields.
文摘The modification procedure of anodic alumina membrane(AAM) was studied. The AAM structure after modification was characterized by nickel nanowires prepared in AAM. Scanning electron microscopy was used to characterize the topography and structure properties of the AAM and nickel nanowires. The transformation of the current during the voltage reduction was studied. The mechanism of current and structure change during modification was discussed. The results show that a root structure produces after the AAM modification. The length of the root structure depends on the velocity of the voltage reduction. Slow voltage reduction leads to a large length of the root structure, otherwise, a short length of the root structure. At the end of the modification, the barrier layer is thin enough to be passed by electrons. Hence, the direct electrodeposition of one-dimensional nanowires can be carried out on the AAM with barrier layer and aluminum matrix successfully without any other treatments.
文摘The pure aluminum and Al Mg Mn alloy were anodized in 4%, 10% and 18.5% phosphoric acid solution, respectively. As for pure Al, the maximum thickness of anodized aluminum oxide (AAO) membrane, 216 nm, is obtained by being anodized in 4% solution. Its average pore diameter is around 70 nm, and pore density exceeds 10 10 /cm 2. Under the same technology condition, the membrane thickness decreases with increment of electrolyte content. TEM images show that element Mg or Mn added into aluminum alloy can damage the integration of AAO membrane. During anodizing of aluminum, the formed oxide layer is amorphous. After being annealed at 600 ℃ for 24 h, it is still amorphous. However, when membrane is annealed at 930 ℃, the amorphous oxide begins to transform to γ Al 2O 3 .
基金This work was supported by the National Natural Science Foundation of China (No. 20023003 and 20128004).
文摘The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates tosynthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and thelayer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm themethodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.
基金the funding support from “Hundred Talents Program” of Zhejiang University and International Joint Laboratory of Chinese Education Ministry on Resource Chemistry at Shanghai Normal Universitythe National Natural Science Foundation of China (No. 91961126) for funding this work。
文摘High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.
文摘Objective The correlation between various formative conditions and the pore characterizationsof the anodic alumina membrane is investigated to seek the optimal conditions for the formation of anodic aluminamembrane. Methods High purity aluminum foils are used as the starting materials. The anodization is conduc-ted in three types of electrolytes, 3% sulfuric acid, 5% sulfuric acid and 2. 7% oxalic acid, respectively, with dif-ferent voltages at for 48h. The characterizations of the pore size, the effective porosity and the pore porosity areobserved and determined by scanning electron microscopy. The hydraulic conductances of the membranes are meas-ured to confirm that the pores are open and evaluate the permselectivity of the membranes. Results The experi-mental result shows that the ordered pore arrays are obtained for oxidation under our experimental conditions. Withthe increasing of the voltage, the pore size and pore porosity increased significantly (P <0.05) , while the effectiveporosity decreased significantly (P <0.05) with the same electrolyte. The pore size formed in 3% sulfuric acid or5% sulfuric acid is much smaller than in 2. 7% oxalic acid as an electrolyte. The hydraulic conductance of anodicalumina membrane that formed under our experimental condition is higher than those of the membranes are availablecurrently used in clinical. Conclusion The results suggest that the optimal conditions for the formation of anodicalumina membrane that used in hemodialysis are in 3% or 5% sulfuric acid with 12. 5V to 17. 5V at for 48h.
基金Supported by the National Natural Science Foundation of China(21838005,21676139)the Higher Education Natural Science Foundation of Jiangsu Province(15KJA530001)+1 种基金the Key Scientific Research and Development Projects of Jiangsu Province(BE201800901)Research Fund of State Key Laboratory of MaterialsOriented Chemical Engineering(ZK201604).
文摘Electrochemical technologies for the on-site treatment of spent acid etchant have received great attention due their ease of operation and economic benefits. On the other hand, a large amount of Cl2 is generated during the electrolysis process, which leads to potential environmental risks. In the present work, a novel threecompartment ceramic membrane flow reactor, including a cathode chamber, an anode chamber, and a gas absorption chamber was developed. The three chambers were divided by an Al2O3 ceramic membrane and a breathable hydrophobic anode diffusion electrode(ADE). The Cl2 evolution onset potential of the ADE was increased to 1.19 V from 1.05 V of the graphite felt, effectively inhibiting the chlorine evolution reaction(CER).The anode-generated Cl2 diffused into the gas absorption chamber through the ADE and was eventually consumed by the H2O2 adsorbent. Cu could be recovered without emitting chlorine due to the special structure of reactor. The current efficiency of copper precipitation and cathode reduction from Cu2+to Cu+reached 97.7%at a working current of 150 m A. These results indicated that the novel membrane reactor had high potential for application in the copper recovery industry.
基金the Natural Science Foundation of China(No.21701202)Henan Province(No.212102210182&222102240038&232102231059&Young Backbone Teacher Funding of Henan province)Natural Science Foundation of Zhongyuan University of Technology(No.K2023MS007&K2023QN006).
文摘Uncontrollable Zn dendrites and side reactions seriously downgrade the cycling stability of the Zn anode,and restrict the commercialization of aqueous zinc ion batteries.Here,PAN-based(PAN,PAN/PMMA)nanofiber membranes with uniform“zincophilic-hydrophobic”sites have been in-situ electrospun on Zn to effectively prevent harmful side reactions and control Zn plating/stripping behavior.The abundant highly-negative functional groups(C≡N and C=O)of PAN/PMMA have strong coordination interactions with Zn2+,which can accelerate Zn2+desolvation and increase the Zn2+migration number.Furthermore,the even distribution of zincophilic sites can help create a uniform Zn deposition environment and enable horizontal Zn deposition.Simultaneously,the inherent“hydrophobicity”of the nonpolar carbon skeleton in PAN/PMMA can prevent Zn corrosion and hydrogen evolution reaction(HER)side reactions,thus improving the cycling stability of the Zn anode.As a result,PAN/PMMA@Zn symmetric cells demonstrated remarkable rate performance and long cycling stability,sustaining efficient operation for over 2000 cycles at 10 mA cm^(−2)with a low polarization voltage below 65 mV.This Zn anode modification strategy by in-situ constructed PAN-based nanofiber membrane has the advantages of simple-preparation,one-step membrane construction,binder-free,uniform distribution of functionalized units,which not only provides a specific scheme for developing advanced Zn anode but also lays a certain research foundation for developing“separator-anode”integrated Zn-based batteries.
基金supported by the Major Research Plan of the National Nat-ural Science Foundation of China(Grant No.91123030)the International Cooperation Foundation of the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2011DFA12220)the National Natural Science Foundation of China(Grant No.61378083)
文摘The porous anodic alumina membranes （PAAMs） have been successfully used as templates for the fabrication of functional nano-materials due to their outstanding regularity and physicochemical properties. In this paper, a transparent double-sided anodic alumina membrane with ultra-thin aluminum substrate was fabricated with the three-step anodic oxidation method in the oxalic acid electrolyte. The characters such as the top-surface morphology, membrane thickness, and depth of nanopores of this three-layer （A1203-A1-A1203） sandwiched nano-structure were controllable through regulating the main anodic oxidation conditions, e.g., anodic oxidation time of various steps, coating remove process. The experiments data revealed that the aluminum substrate is exponential declined with the oxidation time when it was approximately reduced by a few micrometers. This new double-sided anodic alumina membrane can be used as the high-quality functional field emission materials and templates.
基金supported by the Ministry of Science and Technology of China through 863-project under grant 2009AA03Z218the Major Program of the National Natural Science Foundation of China under Grant No.90923012the Research Fund for the Doctoral Program of Higher Education of China under grant 200806980023
文摘A novel soft polymer template containing a double-layer structure,which includes a thin layer of polymethylmethacrylate(PMMA)used as a pattern layer and a thicker layer of polydimethylsiloxane(PDMS)used as a back layer,was fabricated from a replica molding process.Anodic aluminum oxide(AAO)template was used as the replica mold to be replicated to the polymethylmethacrylate layer by a thermal infiltration process under a vacuum condition.Results indicate that PMMA/PDMS soft templates with different sizes could be easily fabricated from the as-prepared AAO replica mold.The PMMA/PDMS soft templates were then employed to imprint a TiO_2 gel for achieving TiO_2 nano-pore arrays.After the imprinting process,the PDMS layer was firstly peeled off and the PMMA layer was then removed into acetonitrile,which can avoid any demolding problems like damages or distortions.The TiO_2 nano-pore arrays with the crystalline of anatase could be obtained at a heat treatment temperature of 450°C.
