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Organosoluble and Light-Colored Fluorinated Polyimides Prepared from Bis[4-(4-amino-2-trifluoronethylphenoxy)phenyl]ether and Aromatic Dianhydrides

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Polymer science - Series B 2023年第4期65卷 514-527页

作者： Yung-Chung Chen Su, Yu-Yang Chiang, Hsun-Ching Department of Chemical and Materials Engineering National Kaohsiung University of Science and Technology Kaohsiung80778 Taiwan National Kaohsiung University of Science and Technology Kaohsiung City80778 Taiwan Department of Opto-Electronic Nano Hybrid Materials Research Material and Chemical Research Laboratories Industrial Technology Research Institute Hsinchu31040 Taiwan Department of Chemical Engineering Tatung University Taipei104 Taiwan

Abstract: Balanced high transparency, thermal properties and organosolublility are urgent requirements for preparing polyimides. In this study, a series of fluorinated polyimides (Va-f) containing a multi-ether fluorinated diamine unit were designed. The corresponding PIs were synthesized through traditionally thermally polycondensation with bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]ether (II) and various commercial aromatic dinahydrides (IIIa-f). In particular, there are four rigid benzene rings and three flexible ether linkages in its fluorinated diamine structure (II), which is expected to achieve a balance in organic solubility and thermal properties. Va-f had inherent viscosity ranging from 0.88 to 1.24 dL/g. In addition, these fluorinated PIs exhibited high organo-solubility in common organic solvents and mechanical properties of tensile strengths of 92–116 MPa, tensile moduli of 2.0–42.3 GPa, elongations at break of 10–36%. Meanwhile, they also exhibited glass transition temperatures (T g s) of 215–265°C, 10 wt % weight-loss temperatures of 525–597°C in N2. Among these PI films, Vf appeared excellent optical transparency, which displayed the cut-off wavelength at 361 nm with b* value of 8.7. For a comparative study, nonfluorinated analogous polyimides VIa-f were also synthesized. As a result, the fluorinated V series showed better organo-solubility, better optical property, lower dielectric constant and lower moisture absorption but without scarified thermal properties. Such attractive comprehensive properties make these fluorinated PIs as potential candidates for application in microelectronics industry. © 2023, Pleiades Publishing, Ltd.

关键词： Solubility

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A novel reprocessable chloroprene rubber based on dynamic disulfide metathesis

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International Journal of Smart and Nano materials 2024年第1期15卷 42-61页

作者： Jianliang Jiang Junxue Zhai Yanqing Chen Dongqi Zhao Yakai Feng School of Chemical Engineering and Technology Collaborative Innovation Center of Chemical Science and Chemical Engineering(Tianjin)Tianjin UniversityTianjinChina R&D Department of China(Yangzhou) Material Handling Tech-Engineering LtdYangzhouChina Key Laboratory of Rubber Plastics of Ministry of Education/Shandong Province (QUsT)School of Polymer Science&EngineeringQingdao University of Science&TechnologyQingdaoChina R&D Department of Tianjin Joaboa Technology Co.Ltd TianjinP.R.China Frontiers Science Center for Synthetic Biology Tianjin UniversityTianjinChina Key Laboratory of Systems Bioengineering(Ministry of Education) Tianjin UniversityTianjinChina

For sustainable application of chloroprene rubber(CR),a new technology is developed by the vulcanization of CR using 2,2'-dithiodipyridine(DPD)as a cross-linking agent with the repro-cessing performance owing to disulfde *** DPD was incorporated into CR vulcanization,the Menschutkin reac-tion between allyl chloride group and pyridine group occurred with a maximum exothermic peak at 184°*** number of effective cross-linking bond at o.5 phr DPD vulcanizate was higher than that at high DPD *** vulcanizate showed high tensile strength(11.12 MPa)and elongation at break(1253±120%)owing to the exchangeable disulfide bond in the *** the catalysis of triphenylphosphine,the metathesis of disulfide compound was improved obviously,which endowed CR/DPD vulcanizates with good recyclability *** cross-linkage maintains its stability at low temperature,thus ensuring the mechanical stability of CR/DPD vulcanizate under the ambient *** and reprocessing of CR/DPD vulcanizate can be conducted with common industrial rubber processing *** reprocessable chloroprene rubber could have potential appli-cation in CR industry,also serve to significantly improve envir-onmental sustainability.

关键词： Chloroprene rubber reprocessable Menschutkin reaction disulfide

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Novel photoactive material and fabrication techniques for solar cells application:nanocellulose-based graphene oxide CdS composite

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Clean Energy 2024年第2期8卷 189-216页

作者： Hassan Oriyomi Shoyiga Stephen Okiemute Akpasi Joseph Akpan Ubani Oluwaseun Amune Sammy Lewis Kiambi Chemistry Department North-West UniversityMafikengSouth Africa Material Science Innovation and Modelling(MaSIM)Research Focus Area Faculty of Natural and Agricultural SciencesNorth-West University(Mafikeng Campus)MmabathoSouth Africa Green Engineering Research Group Chemical Engineering DepartmentDurban University of TechnologyDurbanSouth Africa Industrial Engineering Department Durban University of TechnologyDurbanSouth Africa Chemical Engineering Department Edo State UniversityUzairueNigeria Chemical Engineering Department Vaal University of TechnologyVanderbijlparkSouth Africa

In recent times,solar energy has become one of the largest available sources of renewable energy at our ***,the design of highly efficient solar cells is increasingly becoming crucial as there has been a surge for economically viable alternative energy sources with the lowest *** advances have been made through different routes to make photovoltaic(PV)/solar technologies economically viable,eco-friendly and consequently *** a result,cellulose nanomaterials have become one of the emerging technologies in this regard because of the advantages of high-value bio-based nanostructured materials,such as their abundance and ***-based photoactive nanocomposite materials can be made by integrating conducting photoactive and electroconductive materials with hydrophilic biocompatible *** nanoparticles,such as graphene/reduced graphene oxide cadmium sulphide quantum dots,amongst others,can be introduced into the nanocellulose matrix and can be applied either as charge transporters or photoactive materials in different types of solar ***,in this review,we highlight the optoelectronic properties of different photoactive materials,particularly nanocellulose-based graphene nanocomposites;their efficiencies and drawbacks were *** effect of doping each PV material on the PV performance is also *** is anticipated that the novel material would result in a reduction in the cost of solar cells,jointly enhancing their efficacy in generating environmentally friendly *** the fabrication techniques and equipment play a crucial role in the development of solar cells,the fabrication techniques of bulk-heterojunction(BHJ)cells containing a nanocellulose-based graphene composite and case studies of already fabricated BHJ PV cells with nanocellulose-based graphene composite are discussed.

关键词： nanocellulose-based composite bulk heterojunction graphene composite photoactive materials fabrication techniques solar energy power conversion efficiency

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Electrically manipulating magnetization reversal via energy band engineering

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science China(Physics,Mechanics & Astronomy) 2023年第5期66卷 181-187页

作者： Junwei Tong Yanzhao Wu Feifei Luo Fubo Tian Xianmin Zhang Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China Department of Physics Freie Universität BerlinBerlin 14195Germany State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Realization of a magnetization reversal by an external electric field is vital for developing ultra-low-power spintronic *** this report,starting from energy band engineering,a general design principle is proposed for achieving electrical manipulation of a nonvolatile 180°magnetization reversal.A half semiconductor(HSC)and a bipolar magnetic semiconductor(BMS)are selected as the model of magnetic layers,whose conduction-band minimum and valence-band maximum are in the same and opposite spin states,*** on the analysis of virtual hopping and tight-binding models,the interlayer coupling of HSC/insulator/BMS devices is successfully tuned between ferromagnetic and antiferromagnetic interactions by varying electric field ***,the interlayer coupling nearly disappears after removing the electric field,proving the nonvolatile magnetization *** first-principles calculations,the feasibility of present design strategy is further confirmed by a representative device with the structure of CrBr3/h-BN/2H-VSe_(2).This design guideline and physical phenomena may open an avenue to explore magnetoelectric coupling mechanisms and develop next-generation spintronic devices.

关键词： magnetic semiconductor magnetization reversal energy band engineering

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Radar Absorbing Properties of Barium Hexaferrite Accompanying with Cu Powders in Polymer Composite Coatings 31

Radar Absorbing Properties of Barium Hexaferrite Accompanyin...

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31st Joint Seminar on the Development of materials science in Research and Education, DMSRE 2022

作者： Atay, H. Yllmaz İzmir Katip Çelebi University Department of Material Science and Engineering Çiǧli İzmir35620 Turkey

Radar, which is an electronic and electromagnetic system that works with the use of radio waves to detect and locate objects, has led to the need for radar absorber materials for some military applications, especially for defence and security. In this study, barium hexaferrite and copper powders were used to investigate a radar absorbing composite material. Barium hexaferrite powders were synthesized by Sol-Gel method. Barium hexaferrite and copper powders were added to a polyurethane resin at different loading levels to interpolate the radar absorption property. Metal substrates were covered with these polymeric composite materials. Characterization tests such as X-Ray Diffraction, Scanning Electron Microscopy (SEM) and scratch test were performed. For evaluating the radar absorbing properties of reinforced composites, a Network Analyzer was used. It was concluded that use of barium hexaferrite and copper powders improved absorbing activity of the coatings. Increasing the amount of barium hexaferrite and copper powders in the coatings, increased the radar absorption performance. Besides, very good synergistic effects were obtained in between barium hexaferrite and Cu powders. The reason for this is thought to be their own individual magnetic properties and electrical that work in the radar absorption mechanism. © Published under licence by IOP Publishing Ltd.

关键词： Sol-gels

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Customized 3D-Printed Insoles for Diabetic Foot Care: Finite Element analysis and Machine Learning Approach 7

Customized 3D-Printed Insoles for Diabetic Foot Care: Finite...

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7th International Conference on material Strength and Applied Mechanics, MSAM 2024

作者： Lu, Zhenghui Li, Xin Gao, Zixiang Chen, Hairong Zhang, Qiaolin Xu, Yining Fekete, Gusztáv Gu, Yaodong Faculty of Engineering University of Pannonia Veszprém Hungary Department of Material Science and Technology Audi Hungaria Faculty of Vehicle Engineering Széchenyi István University Gyor Hungary Faculty of Sports Science Ningbo University Ningbo China Doctoral School on Safety and Security Science Óbuda University Budapest Hungary

ISBN: (纸本)9781643685472

Diabetic foot is a common complication in patients with diabetes, which can lead to plantar ulcers and even necessitate amputation. This study aims to utilize finite element analysis to simulate the offloading effects of 3D-printed insoles with various structures on plantar pressure and to explore the use of machine learning in providing optimal plantar pressure offloading solutions for patients with diabetic foot. The results demonstrated that negative Poisson's ratio structured insoles were more effective in reducing plantar pressure (reducing pressure by an average of 39.2%) than barefoot and conventional structures. This was achieved through a unique lateral contraction deformation, which increased the contact area with the foot. The pressure-reducing effect of insoles may be weight-related, suggesting that heavier patients may require stiffer insoles. However, the machine learning algorithm demonstrated a poor fit (only 60.75%) in the task of recommending suitable insoles. In conclusion, this study demonstrated the significant effect of negative Poisson's ratio structured insoles in reducing plantar pressure in diabetic patients, providing new ideas for diabetic foot protection. With the development of data analysis technology in the future, the feasibility and application of personalised insole design will be more promising. © The Author(s), 2024.

关键词： Poisson ratio

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Quantum Polarization in Two-Mode Generalized Binomial State

Quantum Polarization in Two-Mode Generalized Binomial State

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International Conference on Signal Processing and Communication (ICSC)

作者： Anjali Jatwani Amit Verma Department of Physics and Material Science and Engineering Jaypee Institute of Information Technology Noida India

ISBN: (数字)9798331511890

ISBN: (纸本)9798331511906

This study investigates quantum polarization in a two-mode generalized binomial state (TMGBS), a non-classical property of light, using quantum Stokes parameters and crucial in terms of its relationship to the purity and coherence of quantum states. Here we explore the criterion of quantum polarization in a generalized binomial state of light, which features a binomial photon number distribution in light pulses. Previous work by our group has examined other higher-order nonclassicality in single-and two-mode systems of GBS. Here we focus on the degree of polarization, an essential factor for observing entanglement in two-mode quantum states. Our findings emphasize the role of quantum polarization in detecting entanglement between optical modes, a fundamental resource for quantum communication protocols, including quantum teleportation and cryptography. The study demonstrates that TMGBS is an optimal candidate for achieving high degrees of quantum polarization under varied parameters, providing insights that could advance quantum technologies like quantum communication and metrology, where entanglement is pivotal.

关键词： Stokes parameters Polarization Protocols Quantum entanglement Coherence Quantum state Teleportation Optical signal processing Quantum communication Photonics

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High-performance flexible all-solid-state asymmetric supercapacitors based on binder-free MXene/cellulose nanofiber anode and carbon cloth/polyaniline cathode

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Nano Research 2023年第5期16卷 7696-7709页

作者： Xiaoyu Bi Meichun Li Guoqiang Zhou Chaozheng Liu Runzhou Huang Yang Shi Ben Bin Xu Zhanhu Guo Wei Fan Hassan Algadi Shengbo Ge Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsCollege of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580China Integrated Composites Lab Department of Mechanical and Construction EngineeringNorthumbria UniversityNewcastle Upon TyneNE18STUK School of Textile Science and Engineering&Key Laboratory of Functional Textile Material and Product of Ministry of Education Xi'an Polytechnic UniversityXi'an 710048China College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Electrical Engineering Faculty of EngineeringNajran UniversityNajran11001Saudi Arabia

The search for wearable electronics has been attracted great efforts,there is an ever-growing demand for all-solid-state flexible energy storage ***,it is a challenge to obtain both positive and negative electrodes with excellent mechanical strength and match positive and negative charges to achieve high energy densities and operate voltages to satisfy practical application ***,flexible MXene(Ti_(3)C_(2)Tx)/cellulose nanofiber(CNF)composite film negative electrodes(MCNF)were fabricated with a vacuum filtration method,as well as positive electrodes(CP)by combining polyaniline(PANI)with carbon cloth(CC)using an in-situ polymerization *** positive and negative free-standing electrodes exhibited excellent electrochemical behavior and bendable/foldable *** a result,the all-pseudocapacitance asymmetric device of MCNF//CP assembled with charge-matched between anode and cathode achieves an extended voltage window of 1.5 V,high energy density of 30.6 Wh·kg^(−1)(1211 W·kg^(−1)),86%capacitance retention after 5000 cycles,the device maintains excellent bendability,*** work will pave the way for the development of all-pseudocapacitive asymmetric supercapacitors(ASC)with simultaneously preeminent mechanical properties,high energy density,wide operating voltage window.

关键词： MXene cellulose nanofiber polyaniline asymmetric supercapacitors

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Sapphire Fiber Scattering Array Interferometer for Multiplexable High-Temperature Sensing

Sapphire Fiber Scattering Array Interferometer for Multiplex...

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2024 Conference on Lasers and Electro-Optics, CLEO 2024

作者： Shi, Guannan Thomas, Joseph G. Pickrell, Gary Wang, Anbo Zhu, Yizheng Center for Photonics Technology The Bradley Department of Electrical and Computer Engineering Virginia Tech BlacksburgVA24061 United States Center for Photonics Technology Department of Material Science and Engineering Virginia Tech BlacksburgVA24061 United States

ISBN: (纸本)9781957171395

An intrinsic sapphire fiber scattering array interferometer (SAI) is presented. SAI generates robust interferometric signal with a ~20 dB signal-to-noise ratio and is immune to blackbody radiation-induced noise. Multiplexable high-temperature sensing to ~1500°C is demonstrated. © Optica Publishing Group 2024 © 2024 The Author (s)

关键词： Sapphire

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Development of a Quartic Formalism for a Ternary System 8

Development of a Quartic Formalism for a Ternary System

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8th International Congress on the science and Technology of Steelmaking, ICS 2022

作者： Mir, Ishfaq Pande, Manish M. Department of Metallurgical Engineering and Material Science Indian Institute of Technology Bombay Maharashtra Mumbai400076 India

ISBN: (纸本)9780930767136

The activity coefficient (γi) of a component in a ternary system can be represented by Wagner's Taylor series expansion. Alternatively, we can also obtain γI from a Redlich polynomial representing the excess Gibbs free energy (gE) of the system. In the present work, a quartic formalism has been developed for a ternary system to represent thermodynamic properties that connects available interaction parameter data on binary and ternary systems by 1. applying Gibbs Duhem equation to the Taylor's series expansion of the components 2. differentiating (Equation persented) with respect to n1, n2 and n3. It has been found that the interaction parameters are reduced from n2 + 3n to 1/2 (n − 1)(n + 4) due to the interrelationship between various interaction parameters. Therefore, the nth order interaction parameters in nth order truncation are not required as they can be obtained from lower order interaction parameters. © 2022 by the Association for Iron & Steel Technology.

关键词： Expansion

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