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He W, Qi Y, Shen J, Chen X, Fan M, Zhou J, Chen W. Effect of Coating Shell on High-Frequency Polarization Loss of Core-Shell Filler Dielectric Composites: An Alternating-Field Polarization Phase-Field Simulation of BN@SiO 2/PTFE Composite. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5418. [PMID: 37570121 PMCID: PMC10420265 DOI: 10.3390/ma16155418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023]
Abstract
Introducing a coating shell between the filler and matrix is an effective way to reduce the dielectric loss of the particle/matrix dielectric composites. It found that besides the improvement in interface compatibility, there may be some other effects of the coating shell, such as the elimination of the dielectric mismatch. However, the specific mechanism is still unclear due to the absence of an effective model for the quantitative analysis of the relationship between core-shell structure and dielectric loss, hindering the progress of the dielectric composite design. Here, a phase-field model for simulating high-frequency, alternating-field polarization is employed to study the relationship between high-frequency polarization loss and the coating shell in the silicon dioxide coating boron nitride polytetrafluoroethylene-based (BN@SiO2/PTFE) composite. The results show that the dielectric mismatch makes the high-frequency polarization loss spatially localized and periodically time-variant. The reduction of polarization loss depends on the polarization loss of SiO2. To reduce the high-frequency dielectric loss of the composite, the coating shell should not only eliminate the dielectric mismatch, but its dielectric loss must also be lower than that of the core filler. Furthermore, the model provided in this work has the potential to extend the quantitative calculation of non-intrinsic polarization loss and conduction loss.
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Affiliation(s)
| | | | - Jie Shen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China; (W.H.); (Y.Q.); (X.C.); (M.F.); (J.Z.)
| | | | | | | | - Wen Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China; (W.H.); (Y.Q.); (X.C.); (M.F.); (J.Z.)
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Sharudin RW, Md Azmi NS, Hanizan A, Akhbar S, Ahmad Z, Ohshima M. Dynamic Molecular Simulation of Polyethylene/Organoclay Nanocomposites for Their Physical Properties and Foam Morphology. MATERIALS (BASEL, SWITZERLAND) 2023; 16:3122. [PMID: 37109958 PMCID: PMC10146239 DOI: 10.3390/ma16083122] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 03/22/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Polyethylene materials are of great interest to be used in many applications due to their many advantageous characteristics. It is light, highly chemical resistant, easy to process, low in cost and has good mechanical properties. Polyethylene is widely used as a cable-insulating material. However, research is still needed to further improve its insulation quality and properties. In this study, an experimental and alternative approach through a dynamic modeling method was conducted. The main objective was to investigate the effect of modified organoclay concentration on the properties of polyethylene/organoclay nanocomposites by observing their characterization and optical and mechanical properties. The thermogram curve reveals that 2 wt% organoclay used has the highest crystallinity (46.7%) while the highest amount of organoclay used produced the lowest crystallinity (31.2%). The presence of cracks was also observed mostly in the nanocomposite with higher content of organoclay, usually where 2.0 wt% and above of organoclay was used. Morphological observation from simulation results supports the experimental work. Only small pores were observed to form in lower concentrations, and as the concentration was increased to 2.0 wt% and above, the pores present became larger in size. Increasing the concentration of organoclay up to 2.0 wt% reduced the interfacial tension while increasing the concentration above 2.0 wt% did not bring any changes to the interfacial tension value. Different formulations produced different behavior of nanocomposite. Hence the control of the formulation was important to control the final result of the products for appropriate application in different sectors of industry.
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Affiliation(s)
- Rahida Wati Sharudin
- School of Chemical Engineering, College of Engineering, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia
| | - Nik Salwani Md Azmi
- School of Chemical Engineering, College of Engineering, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia
| | - Anuaruddin Hanizan
- School of Chemical Engineering, College of Engineering, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia
| | - Suffiyana Akhbar
- School of Chemical Engineering, College of Engineering, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia
| | - Zakiah Ahmad
- School of Civil Engineering, College of Engineering, Universiti Teknologi MARA, Shah Alam 40450, Selangor, Malaysia
| | - Masahiro Ohshima
- Department of Chemical Engineering, Kyoto University, Kyoto 615-8510, Japan
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Kapourani A, Chachlioutaki K, Andriotis EG, Fatouros DG, Barmpalexis P. Evaluating PAA/PVA thermal crosslinking process during the preparation of in-situ high-drug loading amorphous solid dispersions. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.104030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Meng J, Wang J, Wang L. Simulation Study on the Screening of Hydrophobic Surface Materials for Pipeline Drag Reduction Based on Adsorption Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:11236-11249. [PMID: 36074728 DOI: 10.1021/acs.langmuir.2c01299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Hydrophobic surface drag reduction techniques are effective in reducing the frictional resistance of fluids, the adsorption of liquid molecules on hydrophobic surfaces can reflect the resistance to fluid flow through such solid surfaces. Based on molecular simulation technology, we investigate the adsorption characteristics of water molecules on hydrophobic surfaces to achieve rapid screening of hydrophobic materials in fire-fighting water supply systems. The Monte Carlo method was used to simulate the adsorption process of polymers and to analyze the effects of temperature and fixed adsorption quantity. Contact angle tests were also done to verify polymer hydrophobicity. The isothermal adsorption heat, water molecule distribution, and energy distribution were studied by molecular mechanics and molecular dynamics methods. Then, adsorption localization simulations and electrostatic potential distributions were used to predict possible adsorption sites on hydrophobic surfaces and single-molecule chains. Finally, the interaction energy, diffusion coefficient, and free volume were investigated to explain the adsorption mechanism at the molecular level. Simulation results show that, overall, PTFE was more hydrophobic and PES was more hydrophilic and at 298 K, the number of adsorbed water molecules was ranked as follows: PTFE < PVDF < PVC < PMMA < PPS < CSM < BD-HDI < BD-MDI < BD-TDI < PES. Furthermore, PTFE, PVDF, PVC, PES, and PPS have more stable adsorption configurations on the (0 -1 0) surface. According to the findings, hydrogen bonding dominates the interaction between water molecules and hydrophilic polymers, whereas π-π interactions increase water molecules' diffusion resistance in polymers with benzene rings. In addition, PES contains many sulfone groups and ether bonds, which disorganize the chain arrangement to provide more free volume, whereas the water adsorption rate of PTFE is reduced because its molecular chains are less convoluted and more organized.
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Affiliation(s)
- Junqing Meng
- School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
- State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing), Beijing 100083, China
- Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Jie Wang
- School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
- State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Lijuan Wang
- School of Emergency Management and Safety Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China
- State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing), Beijing 100083, China
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Lu L, Zhao C, Zhang H, Cai F, Wu S. Influence of Specific Structure on the Dielectric and Thermal Performance of Bulk Polymers: Atomistic Molecular Dynamics Simulations of XNBR. MACROMOL THEOR SIMUL 2022. [DOI: 10.1002/mats.202200006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ling Lu
- State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing 100029 P. R. China
| | - Chen Zhao
- School of Metallurgy Northeastern University Shenyang 110819 P. R. China
| | - Hao Zhang
- State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing 100029 P. R. China
| | - Fei Cai
- State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing 100029 P. R. China
- Shenzhen Geim Graphene Center Tsinghua‐Berkeley Shenzhen Institute & Institute of Materials Research Tsinghua Shenzhen International Graduate School Tsinghua University Shenzhen 518055 P. R. China
| | - Sizhu Wu
- State Key Laboratory of Organic‐Inorganic Composites Beijing University of Chemical Technology Beijing 100029 P. R. China
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Kadim EJ, Noorden ZA, Adzis Z, Azis N. Nanoparticles Application in High Voltage Insulation Systems. IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION 2021; 28:1380-1399. [DOI: 10.1109/tdei.2021.009531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Zhang J, Wang D, Wang L, Zuo W, Zhou L, Hu X, Bao D. Effect of Terminal Groups on Thermomechanical and Dielectric Properties of Silica-Epoxy Composite Modified by Hyperbranched Polyester. Polymers (Basel) 2021; 13:2451. [PMID: 34372053 PMCID: PMC8348354 DOI: 10.3390/polym13152451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/18/2021] [Accepted: 07/19/2021] [Indexed: 02/07/2023] Open
Abstract
To study the effect of hyperbranched polyester with different kinds of terminal groups on the thermomechanical and dielectric properties of silica-epoxy resin composite, a molecular dynamics simulation method was utilized. Pure epoxy resin and four groups of silica-epoxy resin composites were established, where the silica surface was hydrogenated, grafted with silane coupling agents, and grafted with hyperbranched polyester with terminal carboxyl and terminal hydroxyl, respectively. Then the thermal conductivity, glass transition temperature, elastic modulus, dielectric constant, free volume fraction, mean square displacement, hydrogen bonds, and binding energy of the five models were calculated. The results showed that the hyperbranched polyester significantly improved the thermomechanical and dielectric properties of the silica-epoxy composites compared with other surface treatments, and the terminal groups had an obvious effect on the enhancement effect. Among them, epoxy composite modified by the hyperbranched polyester with terminal carboxy exhibited the best thermomechanical properties and lowest dielectric constant. Our analysis of the microstructure found that the two systems grafted with hyperbranched polyester had a smaller free volume fraction (FFV) and mean square displacement (MSD), and the larger number of hydrogen bonds and greater binding energy, indicating that weaker strength of molecular segments motion and stronger interfacial bonding between silica and epoxy resin matrix were the reasons for the enhancement of the thermomechanical and dielectric properties.
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Affiliation(s)
- Jianwen Zhang
- School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 211116, China; (J.Z.); (D.W.); (W.Z.); (X.H.); (D.B.)
| | - Dongwei Wang
- School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 211116, China; (J.Z.); (D.W.); (W.Z.); (X.H.); (D.B.)
| | - Lujia Wang
- School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 211116, China; (J.Z.); (D.W.); (W.Z.); (X.H.); (D.B.)
- State Key Laboratory of Internet of Things for Smart City, University of Macau, Macau 999078, China
| | - Wanwan Zuo
- School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 211116, China; (J.Z.); (D.W.); (W.Z.); (X.H.); (D.B.)
| | - Lijun Zhou
- School of Electrical Engineering, Southwest Jiaotong University, Chengdu 611756, China;
| | - Xue Hu
- School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 211116, China; (J.Z.); (D.W.); (W.Z.); (X.H.); (D.B.)
| | - Dingyu Bao
- School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 211116, China; (J.Z.); (D.W.); (W.Z.); (X.H.); (D.B.)
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Kniha K, Hölzle F, Al-Sibai F, Jörg J, Kneer R, Modabber A. Heat analysis of different devices for thermo-explantation of dental implants: a numeric analysis and preclinical in-vitro model. J ORAL IMPLANTOL 2020; 47:455-463. [PMID: 33270868 DOI: 10.1563/aaid-joi-d-20-00046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Thermal treatment may reverse the osseointegration of implants and could become an atraumatic controlled method for implant removal in the future. The aim of this non-random in vitro study was to empirically identify suitable sources for a controlled heating process, in order to generate a homogenous temperature distribution at a threshold level of 47°C for future in vivo research. Two different set-ups evaluating four different sources (water, laser, monopolar and an electrical joule heater device) were used to carry out infrared measurements and numerical calculations at 47°C along the implant axis and along the periimplant area at the axial plane. Furthermore, required time intervals to heat up the implant tip from 33°C to 47°C were determined. The monopolar electric device led to the most uneven and unpredictable implant heating and was therefore excluded. The thermal analysis suggested identical thermal distributions without any significant differences for water and electrical joule sources with a heat maximum at the implant shoulder (p > 0.05). On the other hand, the laser device may produce the temperature maximum in the middle of the implant without any afterglow effect (p < 0.01). When the implant was heated from 33°C up to 47°C, the water device indicated the fastest approach. Thermal distributions of water and laser sources may be suitable for clinical applications. For future research the numerical analysis may suggests an ideal time interval of 120s to 180s for a homogenous implant temperature of 47°C.
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Affiliation(s)
- Kristian Kniha
- Universitatsklinikum Aachen Department of oral and maxillofacial surgery Pauwelsstraße 30 GERMANY Aachen Nordrheinwestfalen 52074 Universitatsklinikum Aachen
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