A novel inorganic-organic layer with outstanding corrosion resistance in a 3.5wt.% NaCl solution was fabricated by taking advantage of the unique interactions between coumarin (COM) molecules and the porous layer form...A novel inorganic-organic layer with outstanding corrosion resistance in a 3.5wt.% NaCl solution was fabricated by taking advantage of the unique interactions between coumarin (COM) molecules and the porous layer formed on Mg alloy. To achieve this aim, the AZ31 Mg alloy coated via microarc oxidation (MAO) coating was placed in an ethanolic solution of COM for 6 and 12 h at 25 ℃. By reducing the surface area exposed to the corrosive species, the donor-acceptor complexes produced by the particular interactions between the COM and MAO surface would successfully prevent the corrosion of Mg alloy substrate. The MAO layer would provide the ideal sites for the charge-transfer-induced physical and chemical locking, leading to uneven organic layer nucleation and crystal growth with a thatch-like structure. To evaluate the formation mechanism of such hybrid composites and highlight the key bonding modes between the COM and MAO, theoretical simulations were conducted.展开更多
The unique interactions between hexadecanoic acid(HA)and albumin(ALB)molecules on the surface of the porous layer of AZ31 Mg alloy were exploited to fabricate a novel hybrid composite film with excellent electrochemic...The unique interactions between hexadecanoic acid(HA)and albumin(ALB)molecules on the surface of the porous layer of AZ31 Mg alloy were exploited to fabricate a novel hybrid composite film with excellent electrochemical stability in a 3.5 wt.%Na Cl solution.Herein,the inorganic layer(IL)obtained by plasma electrolytic oxidation of AZ31 Mg alloy in an alkaline-phosphate-WO_(3)electrolyte was soaked in an organic solution composed of ALB and HA for 10 and 24 h at 60℃.Although albumin and HA may coexist on the same surface of IL,the higher reactivity of ALB molecules would prevent the formation of a thick layer of HA.The donor-acceptor complexes formed due to the unique interactions between ALB and/or HA and IL surface would reduce the area exposed to the corrosive species which in turn would efficiently protect the substrate from corrosion.The porous structure of the IL would provide preferable sites for the physical and chemical locking triggered by charge-transfer phenomena,leading to the inhomogeneous nucleation and crystal growth of a flowery flakes-like organic layer.DFT calculations were performed to reveal the primary bonding modes between the ALB,HA,and IL and to assess the mechanistic insights into the formation of such novel hybrid composites.展开更多
The formation of inorganic-organic hybrids(IOH)on the metallic substrates would play a decisive role in improving their structural and functional features.In this work,the growth of organic coating(OC)consisting of co...The formation of inorganic-organic hybrids(IOH)on the metallic substrates would play a decisive role in improving their structural and functional features.In this work,the growth of organic coating(OC)consisting of coumarin-3-carboxylic acid(3-CCA)and albumin(ALB)on the inorganic layer(IC),produced by plasma electrolysis of AZ31 Mg alloy,led to enabling organically synergistic reactions on the porous inorganic surface,forming a flake-like structure sealing the structural defects of IC.Synergistic actions between OC and IC endow the flake-like structures with chemical protection and photocatalytic performance.Upon contact with a corrosive solution,the IOH layer possesses stable morphologies that delay the corrosive degradation of the whole structure.The electrochemical stability of the sample produced by immersion IC in the organic solution for 10 h(IOH2 sample)was superior to the other samples as it had the lowest corrosion current density(1.69×10^(−10)A·cm^(−2))and the highest top layer resistance(1.2×10^(7)Ω·cm^(2)).Moreover,the IOH layer can photodegrade the organic pollutants in model wastewater,where the highest photocatalytic efficiency of 99.47%was found in the IOH2 sample.Furthermore,computational calculations were performed to assess the relative activity of different parts of the ALB and 3-CCA structures,which provide helpful information into the formation mechanism of the IOH materials.展开更多
基金This work was supported by the National Research Foundation of Korea(NRF)funded by the Korean government(MSIT)(No.2022R1A2C1006743).
文摘A novel inorganic-organic layer with outstanding corrosion resistance in a 3.5wt.% NaCl solution was fabricated by taking advantage of the unique interactions between coumarin (COM) molecules and the porous layer formed on Mg alloy. To achieve this aim, the AZ31 Mg alloy coated via microarc oxidation (MAO) coating was placed in an ethanolic solution of COM for 6 and 12 h at 25 ℃. By reducing the surface area exposed to the corrosive species, the donor-acceptor complexes produced by the particular interactions between the COM and MAO surface would successfully prevent the corrosion of Mg alloy substrate. The MAO layer would provide the ideal sites for the charge-transfer-induced physical and chemical locking, leading to uneven organic layer nucleation and crystal growth with a thatch-like structure. To evaluate the formation mechanism of such hybrid composites and highlight the key bonding modes between the COM and MAO, theoretical simulations were conducted.
基金the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2019R1G1A1099335)supported also by the Mid-Level Researcher National Project of the National Research Foundation(NRF)funded by the Ministry of Science and ICT,Republic of Korea(NRF-2020R1A2C2004192)supported partly by Basic Research Program through the National Research Foundation,Republic of Korea(NRF-2019R1FA1062702)。
文摘The unique interactions between hexadecanoic acid(HA)and albumin(ALB)molecules on the surface of the porous layer of AZ31 Mg alloy were exploited to fabricate a novel hybrid composite film with excellent electrochemical stability in a 3.5 wt.%Na Cl solution.Herein,the inorganic layer(IL)obtained by plasma electrolytic oxidation of AZ31 Mg alloy in an alkaline-phosphate-WO_(3)electrolyte was soaked in an organic solution composed of ALB and HA for 10 and 24 h at 60℃.Although albumin and HA may coexist on the same surface of IL,the higher reactivity of ALB molecules would prevent the formation of a thick layer of HA.The donor-acceptor complexes formed due to the unique interactions between ALB and/or HA and IL surface would reduce the area exposed to the corrosive species which in turn would efficiently protect the substrate from corrosion.The porous structure of the IL would provide preferable sites for the physical and chemical locking triggered by charge-transfer phenomena,leading to the inhomogeneous nucleation and crystal growth of a flowery flakes-like organic layer.DFT calculations were performed to reveal the primary bonding modes between the ALB,HA,and IL and to assess the mechanistic insights into the formation of such novel hybrid composites.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean Government(MSIT)(No.2022R1A2C1006743).
文摘The formation of inorganic-organic hybrids(IOH)on the metallic substrates would play a decisive role in improving their structural and functional features.In this work,the growth of organic coating(OC)consisting of coumarin-3-carboxylic acid(3-CCA)and albumin(ALB)on the inorganic layer(IC),produced by plasma electrolysis of AZ31 Mg alloy,led to enabling organically synergistic reactions on the porous inorganic surface,forming a flake-like structure sealing the structural defects of IC.Synergistic actions between OC and IC endow the flake-like structures with chemical protection and photocatalytic performance.Upon contact with a corrosive solution,the IOH layer possesses stable morphologies that delay the corrosive degradation of the whole structure.The electrochemical stability of the sample produced by immersion IC in the organic solution for 10 h(IOH2 sample)was superior to the other samples as it had the lowest corrosion current density(1.69×10^(−10)A·cm^(−2))and the highest top layer resistance(1.2×10^(7)Ω·cm^(2)).Moreover,the IOH layer can photodegrade the organic pollutants in model wastewater,where the highest photocatalytic efficiency of 99.47%was found in the IOH2 sample.Furthermore,computational calculations were performed to assess the relative activity of different parts of the ALB and 3-CCA structures,which provide helpful information into the formation mechanism of the IOH materials.