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Jia J, Giannakis S, Li D, Yan B, Lin T. Efficient and sustainable photocatalytic inactivation of E. coli by an innovative immobilized Ag/TiO 2 photocatalyst with peroxymonosulfate (PMS) under visible light. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:166376. [PMID: 37595906 DOI: 10.1016/j.scitotenv.2023.166376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 08/20/2023]
Abstract
A novel catalytic system for effective photocatalytic inactivation of Escherichia coli (E. coli) was constructed by anchoring Ag nanoparticles (AgNPs) on silane coupling agent (SCA) pretreated TiO2 nano-tube arrays (Ag/SCA/TiO2NTAs). Morphology and structural analyses revealed that SCA could disperse AgNPs evenly on TiO2NTAs, thus inducing a superior surface plasmon resonance (SPR) effect. Ag/SCA/TiO2NTAs catalyst exhibited excellent inactivation performance when in the presence of peroxymonosulfate (PMS) and visible light (VL), with 6-log E. coli was completely inactivated within 60 min, which was 5.3, 12.5 and 13.2 times higher than that of Ag/SCA/TiO2NTAs/VL, PMS/VL and Ag/SCA/TiO2NTAs/PMS/dark systems, respectively. Additionally, the photocatalyst exhibited a highly reusable property, with the inactivation performance almost unchanged after ten cycles of uses with minimal Ag leaching. The inactivation mechanism analysis demonstrated that both radical (SO4•-, OH) and non-radical (h+, 1O2) pathways involved in E. coli inactivation, and SCA played a pivotal role in the production of reactive species. Chloride ions (Cl-) greatly enhanced the inactivation efficiency, while bicarbonate (HCO3-) and phosphate (H2PO4-) showed an inhibitory effect. Humic acid (HA) displayed a dual effect on inactivation performance, where the low concentration of HA facilitated the bacteria inactivation, while the higher dose suppressed bacteria inactivation. Moreover, the system exhibited excellent inactivation performance in tap water. This work first used SCA as the binder to fix AgNPs on TiO2NTAs for VL photocatalytic inactivation of bacteria with the assistance of PMS, which was expected to provide some insights into the practical treatment of drinking water.
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Affiliation(s)
- Jialin Jia
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Stefanos Giannakis
- Universidad Politécnica de Madrid, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Departamento de Ingeniería Civil: Hidráulica, Energía y Medio Ambiente, Environment, Coast and Ocean Research Laboratory (ECOREL-UPM), c/ Profesor Aranguren, 3, ES-28040, Madrid, Spain.
| | - Dong Li
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, PR China
| | - Boyin Yan
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
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2
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Zhang T, Zhang C, Du S, Zhang Z, Lu W, Su P, Jiao Y, Zhao Y. A review: The formation, prevention, and remediation of acid mine drainage. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:111871-111890. [PMID: 37848792 DOI: 10.1007/s11356-023-30220-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 09/27/2023] [Indexed: 10/19/2023]
Abstract
In abandoned open-pit coal mines, surface water and groundwater form acidic waters with high concentrations of metal ions due to chemical interactions with ores such as pyrite, and the formation of acid mine drainage (AMD) is one of the major sources of pollution of world concern. For this reason, this paper reviews the formation mechanisms and influencing factors of AMD. It also describes the prediction, prevention, and remediation techniques for AMD, identifying key research gaps. It also discusses the current challenges and shortcomings faced globally in the management of AMD. The formation of AMD is mainly caused by the oxidation of pyrite in mines, but it is mainly influenced by history, climate, topography, and hydrogeology, making the formation mechanism of AMD extremely complex. Currently, the remediation technologies for AMD mainly include active treatment and passive treatment, which can effectively neutralize acidic wastewater. However, the prediction technology for AMD is blank, and the source treatment technology such as passivation and microencapsulation only stays in the experimental stage. This leads to the high cost of treatment technologies at this stage and the inability to identify potential risks in mines. Overall, this review provides remediation tools for AMD from predicting root causes to treatment. Geophysical technology is an effective method for predicting the motion path and pollution surface of AMD in the future, and resource recovery for AMD is a key point that must be paid attention to in the future. Finally, integrated treatment technologies that deserve further exploration need to be emphasized.
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Affiliation(s)
- Tengzhuo Zhang
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, People's Republic of China
| | - Chunhui Zhang
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, People's Republic of China.
| | - Song Du
- General Prospecting Institute of China National Administration of Coal Geology, Beijing, 100039, People's Republic of China
| | - Zhao Zhang
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, People's Republic of China
| | - Wenjing Lu
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, People's Republic of China
| | - Peidong Su
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, People's Republic of China
| | - Yanan Jiao
- School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, People's Republic of China
| | - Yue Zhao
- General Prospecting Institute of China National Administration of Coal Geology, Beijing, 100039, People's Republic of China
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3
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Dong A, Sun M, Gui Y. Adsorption and Gas-Sensing Properties of Ag n (n = 1-4) Cluster Doped GeSe for CH 4 and CO Gases in Oil-Immersed Transformer. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:4203. [PMID: 36500826 PMCID: PMC9739156 DOI: 10.3390/nano12234203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/21/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
The adsorption mechanism of CO and CH4 on GeSe, modified with the most stable 1-4 Ag-atom clusters, is studied with the help of density functional theory. Adsorption distance, adsorption energy, total density of states (TDOS), projected density of states (PDOS), and molecular orbital theory were all used to analyze the results. CO was found to chemisorb exothermically on GeSe, independent of Ag cluster size, with Ag4-GeSe representing the optimum choice for CO gas sensors. CH4, in contrast, was found to chemisorb on Ag-GeSe and Ag2-GeSe and to physisorb on Ag3-GeSe and Ag4-GeSe. Here, Ag GeSe was found to be the optimum choice for CH4 gas sensors. Overall, our calculations suggest that GeSe modified by Ag clusters of different sizes could be used to advantage to detect CO and CH4 gas in ambient air.
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Affiliation(s)
- Aijuan Dong
- Qinhuangdao Vocational and Technical College, Qinhuangdao 066100, China
| | - Meiling Sun
- Qinhuangdao Vocational and Technical College, Qinhuangdao 066100, China
| | - Yingang Gui
- College of Engineering and Technology, Southwest University, Chongqing 400715, China
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4
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Cao Z, Zhou C, Wang J, Wei G, Li T, Zhuang K. Theoretical Study of Adsorption Behavior of Dimethylamine and Ammonia on Al- and Ga-Doped BN Monolayer Surfaces Based on DFT. ACS OMEGA 2022; 7:37857-37866. [PMID: 36312343 PMCID: PMC9607678 DOI: 10.1021/acsomega.2c04963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Endogenous volatile organic compounds (VOCs) can reflect human health status and be used for clinical diagnosis and health monitoring. Dimethylamine and ammonia are the signature VOC gases of nephropathy. In order to find a potential gas sensitivity material for the detection of both signature VOC gases of nephropathy, this paper investigated the adsorption properties of dimethylamine and ammonia on Al- and Ga-doped BN monolayers based on density functional theory. Through analyzing the adsorption energy, adsorption distance, charge transfer, density of states, and HOMO/LUMO, the results indicated that the adsorption effect of Al- and Ga-doped BN monolayers to dimethylamine and ammonia is probably good, and these nanomaterials have the potential to be applied for nephropathy monitoring and clinical diagnosis.
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Affiliation(s)
- Zhengqin Cao
- College
of Electrical Engineering, Chongqing University
of Science and Technology, Chongqing401331, China
| | - Changli Zhou
- College
of Electrical Engineering, Chongqing University
of Science and Technology, Chongqing401331, China
| | - Jia Wang
- College
of medical informatics, Chongqing Medical
University, Chongqing400016, China
| | - Gang Wei
- College
of Electrical Engineering, Chongqing University
of Science and Technology, Chongqing401331, China
| | - Ting Li
- Traditional
Chinese medicine hospital of Jiulongpo district in Chongqing, Chongqing400050, China
| | - Kai Zhuang
- College
of Electrical Engineering, Chongqing University
of Science and Technology, Chongqing401331, China
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5
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Ge M, He Z, Song Z. Polydiacetylene/organic magadiite nanocomposite film with stable reversible structure and reversible thermochromism. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03236-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Zhang A, Dong A, Gui Y. Gas-Sensing Properties of B/N-Modified SnS 2 Monolayer to Greenhouse Gases (NH 3, Cl 2, and C 2H 2). MATERIALS 2022; 15:ma15155152. [PMID: 35897583 PMCID: PMC9330703 DOI: 10.3390/ma15155152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 02/04/2023]
Abstract
The adsorption capacity of intrinsic SnS2 to NH3, Cl2 and C2H2 is very weak. However, non-metallic elements B and N have strong chemical activity, which can significantly improve the conductivity and gas sensitivity of SnS2. Based on density functional theory, SnS2 was modified with B and N atoms to analyze its adsorption mechanism and gas sensitivity for NH3, Cl2 and C2H2 gases. The optimal structure, adsorption energy, state density and frontier molecular orbital theory are analyzed, and the results are in good agreement with the experimental results. The results show that the adsorption of gas molecules is exothermic and spontaneous. Only the adsorption of NH3 and Cl2 on B-SnS2 belongs to chemical adsorption, whereas other gas adsorption systems belong to physical adsorption. Moderate adsorption distance, large adsorption energy, charge transfer and frontier molecular orbital analysis show that gas adsorption leads to the change of the conductivity of the modified SnS2 system. The adsorption capacity of B-SnS2 to these gases is Cl2 > NH3 > C2H2. The adsorption capacity of N-SnS2 is NH3 > C2H2 > Cl2. Therefore, according to different conductivity changes, B-SnS2 and N-SnS2 materials can be developed for greenhouse gas detection of gas sensors.
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Affiliation(s)
- Aijuan Zhang
- College of Physics and Electronic Engineering, Xianyang Normal University, Xianyang 712000, China;
| | - Aijuan Dong
- Qinhuangdao Vocational and Technical College, Qinhuangdao 066100, China
- Correspondence:
| | - Yingang Gui
- College of Engineering and Technology, Southwest University, Chongqing 400715, China;
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7
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Gong W, Liu J, Gui Y, Huang H. Adsorption of Greenhouse Decomposition Products on Ag 2O-SnS 2 and CuO-SnS 2 Surfaces. ACS OMEGA 2022; 7:21043-21051. [PMID: 35935290 PMCID: PMC9347902 DOI: 10.1021/acsomega.2c01828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
In this paper, based on density functional theory, the adsorption mechanism and gas sensitivity of Ag2O/CuO-modified SnS2 were analyzed. The results were analyzed according to the adsorption energy, total density of states, partial density of states, and frontier molecular orbital theory. The results show that the adsorption of all gas molecules is exothermic. NH3, Cl2, and C2H2 gases are chemisorbed on the modified SnS2 surfaces. After gas adsorption, the energy gap of the base changes by more than 10%, which fully shows that the conductivity changes greatly after gas adsorption, which can be reflected in the macroscopic resistance change. Ag2O-SnS2 is suitable as a gas sensor for NH3 gas sensors in terms of moderate adsorption distance, large adsorption energy, charge transfer, and frontier molecular orbital theory, while CuO-SnS2 is more suitable as a C2H2 gas sensor.
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Affiliation(s)
- Wei Gong
- College
of Electronic Information Engineering, Chongqing
Technology and Business Institute, Chongqing 400052, China
| | - Jingcheng Liu
- College
of Electronic Information Engineering, Chongqing
Technology and Business Institute, Chongqing 400052, China
- Liquor
Making Microbial Application & Detection Technology of Luzhou
Key Laboratory, Luzhou Vocational &
Technical College, Luzhou 646000, China
| | - Yingang Gui
- College
of Engineering and Technology, Southwest
University, Chongqing 400715, China
| | - Heqing Huang
- College
of Electronic Information Engineering, Chongqing
Technology and Business Institute, Chongqing 400052, China
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8
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Long J, Li C, Li Y. Enhancement of Mechanical and Bond Properties of Epoxy Adhesives Modified by SiO 2 Nanoparticles with Active Groups. Polymers (Basel) 2022; 14:polym14102052. [PMID: 35631934 PMCID: PMC9143029 DOI: 10.3390/polym14102052] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 04/27/2022] [Accepted: 04/30/2022] [Indexed: 01/27/2023] Open
Abstract
In order to improve the mechanical and bond properties of epoxy adhesives for their wide scope of applications, modified epoxy adhesives were produced in this study with SiO2 nanoparticles of 20 nm in size, including inactive groups, NH2 active groups, and C4H8 active groups. The mechanical properties of specimens were examined, and an investigation was conducted into the effects of epoxy adhesive modified by three kinds of SiO2 nanoparticles on the bond properties of carbon fiber reinforced polymer and steel (CFRP/steel) double lap joints. According to scanning electron microscopy (SEM), the distribution effect in epoxy adhesive of SiO2 nanoparticles modified by active groups was better than that of inactive groups. When the mass fraction of SiO2-C4H8 nanoparticles was 0.05%, the tensile strength, tensile modulus, elongation at break, bending strength, flexural modulus, and impact strength of the epoxy adhesives reached their maximum, which were 47.63%, 44.81%, 57.31%, 62.17%, 33.72%, 78.89%, and 68.86% higher than that of the EP, respectively, and 8.45%, 9.52%, 9.24%, 20.22%, 17.76%, 20.18%, and 12.65% higher than that of the inactive groups of SiO2 nanoparticles, respectively. The SiO2 nanoparticles modified with NH2 or C4H8 active groups were effective in improving the ultimate load-bearing capacity and bond properties of epoxy adhesives glued to CFRP/steel double lap joints, thus increasing the strain and interface shear stress peak value of the CFRP surface.
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Affiliation(s)
- Jiejie Long
- School of Civil Engineering and Architecture, Changsha University of Science and Technology, No. 960 Wanjiali Road, Changsha 410114, China;
| | - Chuanxi Li
- School of Civil Engineering and Architecture, Changsha University of Science and Technology, No. 960 Wanjiali Road, Changsha 410114, China;
- Correspondence: (C.L.); (Y.L.)
| | - You Li
- School of Civil Engineering, Hunan University of Technology, Zhuzhou 412007, China
- Correspondence: (C.L.); (Y.L.)
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Zhang A, Dong Q, Gui Y, Li J, Wan F. Gas-Sensing Property of TM-MoTe 2 Monolayer towards SO 2, SOF 2, and HF Gases. Molecules 2022; 27:3176. [PMID: 35630656 PMCID: PMC9147850 DOI: 10.3390/molecules27103176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 11/18/2022] Open
Abstract
Detecting the characteristic decomposition products (SO2, SOF2, and HF) of SF6 is an effective way to diagnose the electric discharge in SF6-insulated equipment. Based on first-principles calculations, Au, Ag, and Cu were chosen as the surface modification transition metal to improve the adsorption and gas-sensing properties of MoTe2 monolayer towards SO2, SOF2, and HF gases. The results show that Au, Ag, and Cu atoms tend to be trapped by TH sites on the MoTe2 monolayer, and the binding strength increases in the order of Ag < Au < Cu. In gas adsorption, the moderate adsorption energy provides the basis that the TM-MoTe2 monolayer can be used as gas-sensing material for SO2, SOF2, and HF. The conductivity of the adsorption system changes significantly. The conductivity decreases upon gases adsorption on TM-MoTe2 monolayer, except the conductivity of Ag-MoTe2 monolayer increases after interacting with SOF2 gas.
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Affiliation(s)
- Aijuan Zhang
- College of Physics and Electronic Engineering, Xianyang Normal University, Xianyang 712000, China; (A.Z.); (Q.D.); (J.L.); (F.W.)
| | - Qunfeng Dong
- College of Physics and Electronic Engineering, Xianyang Normal University, Xianyang 712000, China; (A.Z.); (Q.D.); (J.L.); (F.W.)
| | - Yingang Gui
- College of Engineering and Technology, Southwest University, Chongqing 400715, China
| | - Jinfang Li
- College of Physics and Electronic Engineering, Xianyang Normal University, Xianyang 712000, China; (A.Z.); (Q.D.); (J.L.); (F.W.)
| | - Feng Wan
- College of Physics and Electronic Engineering, Xianyang Normal University, Xianyang 712000, China; (A.Z.); (Q.D.); (J.L.); (F.W.)
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10
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Gu X, Hou J, Ai S. Effect of silane modified
nano‐SiO
2
on the mechanical properties and compatibility of
PBAT
/lignin composite films. J Appl Polym Sci 2021. [DOI: 10.1002/app.52051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Xinhui Gu
- College of Chemistry and Material Science Shandong Agricultural University Tai'an China
| | - Juying Hou
- College of Chemistry and Material Science Shandong Agricultural University Tai'an China
| | - Shiyun Ai
- College of Chemistry and Material Science Shandong Agricultural University Tai'an China
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Aziz T, Ullah A, Fan H, Jamil MI, Khan FU, Ullah R, Iqbal M, Ali A, Ullah B. Recent Progress in Silane Coupling Agent with Its Emerging Applications. JOURNAL OF POLYMERS AND THE ENVIRONMENT 2021; 29:3427-3443. [DOI: 10.1007/s10924-021-02142-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/31/2021] [Indexed: 07/25/2024]
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13
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Effect of Aminosilane Coupling Agent-Modified Nano-SiO2 Particles on Thermodynamic Properties of Epoxy Resin Composites. Processes (Basel) 2021. [DOI: 10.3390/pr9050771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
From the perspective of improving the thermodynamic properties of epoxy resin, it has become the focus of research to enhance the operational stability of GIS (Gas Insulated Substation) basin insulators for UHV (Ultra-High Voltage) equipment. In this paper, three aminosilane coupling agents with different chain lengths, (3-Aminopropyl)trimethoxysilane (KH550), Aminoethyl)-γ-aminopropyltrimethoxysilane (KH792) and 3-[2-(2-Aminoethylamino)ethylamino]propyl-trimethoxysilane (TAPS), were used to modify nano-SiO2 and doped into epoxy resin, respectively, using a combination of experimental and molecular dynamics simulations. The experimental results showed that the surface-grafted KH792 model of nano-SiO2 exhibited the most significant improvement in thermal properties compared with the undoped nanoparticle model. The storage modulus increased by 276 MPa and the Tg increased by 61 K. The simulation results also showed that the mechanical properties of the nano-SiO2 surface-grafted KH792 model were about 3 times higher than that of the undoped nanoparticle model, the Tg increased by 36.5 K, and the thermal conductivity increased by 24.5%.
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14
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Molecular Simulation of Improved Mechanical Properties and Thermal Stability of Insulation Paper Cellulose by Modification with Silane-Coupling-Agent-Grafted Nano-SiO2. Processes (Basel) 2021. [DOI: 10.3390/pr9050766] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Cellulose is an important part of transformer insulation paper. Thermal aging of cellulose occurs in long-term operation of transformers, which deteriorates the mechanical properties and thermal stability of cellulose, resulting in a decrease in the transformer life. Therefore, improvement of the mechanical properties and thermal stability of cellulose has become a research hotspot. In this study, the effects of different silane coupling agents on the mechanical properties and thermal stability of modified cellulose were studied. The simulation results showed that the mechanical parameters of cellulose are only slightly improved by KH560 (γ-glycidyl ether oxypropyl trimethoxysilane) and KH570 (γ-methylacrylloxy propyl trimethoxy silane) modified nano-SiO2, while the mechanical parameters of cellulose are greatly improved by KH550 (γ-aminopropyl triethoxy silane) and KH792 (N-(2-aminoethyl)-3-amino propyl trimethoxy silane) modified nano-SiO2. The glass-transition temperature of the composite model is 24 K higher than that of the unmodified model. The mechanism of the change of the glass-transition temperature was analyzed from the point of view of free-volume theory. The main reason for the change of the glass-transition temperature is that the free volume abruptly changes, which increases the space for movement of the cellulose chain and accelerates the whole movement of the molecular chain. Therefore, modifying cellulose with KH792-modified nano-SiO2 can significantly enhance the thermal stability of cellulose.
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15
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Fu S, Zhao X, Zhou Z, Li M, Zhu L. Effective removal of odor substances using intimately coupled photocatalysis and biodegradation system prepared with the silane coupling agent (SCA)-enhanced TiO 2 coating method. WATER RESEARCH 2021; 188:116569. [PMID: 33142118 DOI: 10.1016/j.watres.2020.116569] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/17/2020] [Accepted: 10/24/2020] [Indexed: 06/11/2023]
Abstract
Intimately coupled photocatalysis and biodegradation (ICPB) combining photocatalysis with microbial degradation is an attractive wastewater treatment technology. However, when prepared in conventional ways, the supported-photocatalysts aggregate frequently, detach easily from carriers, and prohibit the colonization of microorganisms inside the carriers. To overcome these challenges, silane coupling agent (SCA)-enhanced TiO2 coating method is developed in this study. The coupling agent γ-glycidoxypropyltrimethoxysilane (KH560) greatly enhanced the adhesion between photocatalysts and the carrier through ether and Ti-O-Si linkages. The dense TiO2 layer was firmly adhered to the carrier outer surface, and the loading amount reached 351.8±8.2 mg/g, over ten times higher than using the powder sintering method (31.5±2.4 mg/g). In the ICPB system constructed with the KH560-enhanced TiO2-supported polyurethane sponge (KH560-TiO2-PU) carriers, removal efficiencies of two model odor substances, 2-methylisoborneol (2-MIB) and geosmin (GSM), reached 88.9±0.3% and 85.0±1.0% in 12 h at an initial concentration of 500 ng/L respectively, which were 17.7±0.6% and 19.4±0.4% greater than those of the ICPB system prepared with the powder sintering method. After 5 operating cycles, the novel ICPB system remained stable with high 2-MIB and GSM removal efficiencies, reaching 89.9±0.8% and 86.1±0.2% respectively after 12h, while TiO2 peeling ratio was as low as 5.0±2.8%. Biofilms attached onto the carrier inner surface were resilient over the operating cycles with the increase of both richness and diversity of microbial communities. Analysis of biofilm microbial community and pollutant degradation pathways revealed the enhanced removal of 2-MIB and GSM in the novel ICPB system might be attributed to multiple factors. First, the alleviated aggregation and increased adhesion of photocatalysts onto carriers improved the overall photocatalysis efficiency. Second, biofilm inside of the carrier was protected and the microbial activity was well remained. Third, photocatalytic intermediate products were efficiently biodegraded by the enriched functional microbial populations, such as Thauera and Flavobacterium, with little concern of excessive oxidation. Collectively, this research provides a new technological solution that synergizes photocatalysis and biodegradation for effective removal of odorous substances in polluted natural water.
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Affiliation(s)
- Shiyuan Fu
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China
| | - Xinyu Zhao
- Hangzhou No. 14 High School, Hanzhou 310006, China
| | - Zhou Zhou
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China
| | - Mengyan Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, United States
| | - Liang Zhu
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058, China; Zhejiang Provincial Engineering Laboratory of Water Pollution Control, 388 Yuhangtang Road, Hangzhou 310058, China.
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